Linux 6.9

[linux.git] / drivers / iommu / intel / iommu.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright © 2006-2014 Intel Corporation.
 *
 * Authors: David Woodhouse <[email protected]>,
 *          Ashok Raj <[email protected]>,
 *          Shaohua Li <[email protected]>,
 *          Anil S Keshavamurthy <[email protected]>,
 *          Fenghua Yu <[email protected]>
 *          Joerg Roedel <[email protected]>
 */

#define pr_fmt(fmt)     "DMAR: " fmt
#define dev_fmt(fmt)    pr_fmt(fmt)

#include <linux/crash_dump.h>
#include <linux/dma-direct.h>
#include <linux/dmi.h>
#include <linux/memory.h>
#include <linux/pci.h>
#include <linux/pci-ats.h>
#include <linux/spinlock.h>
#include <linux/syscore_ops.h>
#include <linux/tboot.h>
#include <uapi/linux/iommufd.h>

#include "iommu.h"
#include "../dma-iommu.h"
#include "../irq_remapping.h"
#include "pasid.h"
#include "cap_audit.h"
#include "perfmon.h"

#define ROOT_SIZE               VTD_PAGE_SIZE
#define CONTEXT_SIZE            VTD_PAGE_SIZE

#define IS_GFX_DEVICE(pdev) ((pdev->class >> 16) == PCI_BASE_CLASS_DISPLAY)
#define IS_USB_DEVICE(pdev) ((pdev->class >> 8) == PCI_CLASS_SERIAL_USB)
#define IS_ISA_DEVICE(pdev) ((pdev->class >> 8) == PCI_CLASS_BRIDGE_ISA)
#define IS_AZALIA(pdev) ((pdev)->vendor == 0x8086 && (pdev)->device == 0x3a3e)

#define IOAPIC_RANGE_START      (0xfee00000)
#define IOAPIC_RANGE_END        (0xfeefffff)
#define IOVA_START_ADDR         (0x1000)

#define DEFAULT_DOMAIN_ADDRESS_WIDTH 57

#define __DOMAIN_MAX_PFN(gaw)  ((((uint64_t)1) << ((gaw) - VTD_PAGE_SHIFT)) - 1)
#define __DOMAIN_MAX_ADDR(gaw) ((((uint64_t)1) << (gaw)) - 1)

/* We limit DOMAIN_MAX_PFN to fit in an unsigned long, and DOMAIN_MAX_ADDR
   to match. That way, we can use 'unsigned long' for PFNs with impunity. */
#define DOMAIN_MAX_PFN(gaw)     ((unsigned long) min_t(uint64_t, \
                                __DOMAIN_MAX_PFN(gaw), (unsigned long)-1))
#define DOMAIN_MAX_ADDR(gaw)    (((uint64_t)__DOMAIN_MAX_PFN(gaw)) << VTD_PAGE_SHIFT)

/* IO virtual address start page frame number */
#define IOVA_START_PFN          (1)

#define IOVA_PFN(addr)          ((addr) >> PAGE_SHIFT)

static void __init check_tylersburg_isoch(void);
static int rwbf_quirk;

/*
 * set to 1 to panic kernel if can't successfully enable VT-d
 * (used when kernel is launched w/ TXT)
 */
static int force_on = 0;
static int intel_iommu_tboot_noforce;
static int no_platform_optin;

#define ROOT_ENTRY_NR (VTD_PAGE_SIZE/sizeof(struct root_entry))

/*
 * Take a root_entry and return the Lower Context Table Pointer (LCTP)
 * if marked present.
 */
static phys_addr_t root_entry_lctp(struct root_entry *re)
{
        if (!(re->lo & 1))
                return 0;

        return re->lo & VTD_PAGE_MASK;
}

/*
 * Take a root_entry and return the Upper Context Table Pointer (UCTP)
 * if marked present.
 */
static phys_addr_t root_entry_uctp(struct root_entry *re)
{
        if (!(re->hi & 1))
                return 0;

        return re->hi & VTD_PAGE_MASK;
}

static int device_rid_cmp_key(const void *key, const struct rb_node *node)
{
        struct device_domain_info *info =
                rb_entry(node, struct device_domain_info, node);
        const u16 *rid_lhs = key;

        if (*rid_lhs < PCI_DEVID(info->bus, info->devfn))
                return -1;

        if (*rid_lhs > PCI_DEVID(info->bus, info->devfn))
                return 1;

        return 0;
}

static int device_rid_cmp(struct rb_node *lhs, const struct rb_node *rhs)
{
        struct device_domain_info *info =
                rb_entry(lhs, struct device_domain_info, node);
        u16 key = PCI_DEVID(info->bus, info->devfn);

        return device_rid_cmp_key(&key, rhs);
}

/*
 * Looks up an IOMMU-probed device using its source ID.
 *
 * Returns the pointer to the device if there is a match. Otherwise,
 * returns NULL.
 *
 * Note that this helper doesn't guarantee that the device won't be
 * released by the iommu subsystem after being returned. The caller
 * should use its own synchronization mechanism to avoid the device
 * being released during its use if its possibly the case.
 */
struct device *device_rbtree_find(struct intel_iommu *iommu, u16 rid)
{
        struct device_domain_info *info = NULL;
        struct rb_node *node;
        unsigned long flags;

        spin_lock_irqsave(&iommu->device_rbtree_lock, flags);
        node = rb_find(&rid, &iommu->device_rbtree, device_rid_cmp_key);
        if (node)
                info = rb_entry(node, struct device_domain_info, node);
        spin_unlock_irqrestore(&iommu->device_rbtree_lock, flags);

        return info ? info->dev : NULL;
}

static int device_rbtree_insert(struct intel_iommu *iommu,
                                struct device_domain_info *info)
{
        struct rb_node *curr;
        unsigned long flags;

        spin_lock_irqsave(&iommu->device_rbtree_lock, flags);
        curr = rb_find_add(&info->node, &iommu->device_rbtree, device_rid_cmp);
        spin_unlock_irqrestore(&iommu->device_rbtree_lock, flags);
        if (WARN_ON(curr))
                return -EEXIST;

        return 0;
}

static void device_rbtree_remove(struct device_domain_info *info)
{
        struct intel_iommu *iommu = info->iommu;
        unsigned long flags;

        spin_lock_irqsave(&iommu->device_rbtree_lock, flags);
        rb_erase(&info->node, &iommu->device_rbtree);
        spin_unlock_irqrestore(&iommu->device_rbtree_lock, flags);
}

/*
 * This domain is a statically identity mapping domain.
 *      1. This domain creats a static 1:1 mapping to all usable memory.
 *      2. It maps to each iommu if successful.
 *      3. Each iommu mapps to this domain if successful.
 */
static struct dmar_domain *si_domain;
static int hw_pass_through = 1;

struct dmar_rmrr_unit {
        struct list_head list;          /* list of rmrr units   */
        struct acpi_dmar_header *hdr;   /* ACPI header          */
        u64     base_address;           /* reserved base address*/
        u64     end_address;            /* reserved end address */
        struct dmar_dev_scope *devices; /* target devices */
        int     devices_cnt;            /* target device count */
};

struct dmar_atsr_unit {
        struct list_head list;          /* list of ATSR units */
        struct acpi_dmar_header *hdr;   /* ACPI header */
        struct dmar_dev_scope *devices; /* target devices */
        int devices_cnt;                /* target device count */
        u8 include_all:1;               /* include all ports */
};

struct dmar_satc_unit {
        struct list_head list;          /* list of SATC units */
        struct acpi_dmar_header *hdr;   /* ACPI header */
        struct dmar_dev_scope *devices; /* target devices */
        struct intel_iommu *iommu;      /* the corresponding iommu */
        int devices_cnt;                /* target device count */
        u8 atc_required:1;              /* ATS is required */
};

static LIST_HEAD(dmar_atsr_units);
static LIST_HEAD(dmar_rmrr_units);
static LIST_HEAD(dmar_satc_units);

#define for_each_rmrr_units(rmrr) \
        list_for_each_entry(rmrr, &dmar_rmrr_units, list)

static void intel_iommu_domain_free(struct iommu_domain *domain);

int dmar_disabled = !IS_ENABLED(CONFIG_INTEL_IOMMU_DEFAULT_ON);
int intel_iommu_sm = IS_ENABLED(CONFIG_INTEL_IOMMU_SCALABLE_MODE_DEFAULT_ON);

int intel_iommu_enabled = 0;
EXPORT_SYMBOL_GPL(intel_iommu_enabled);

static int dmar_map_gfx = 1;
static int intel_iommu_superpage = 1;
static int iommu_identity_mapping;
static int iommu_skip_te_disable;

#define IDENTMAP_GFX            2
#define IDENTMAP_AZALIA         4

const struct iommu_ops intel_iommu_ops;
static const struct iommu_dirty_ops intel_dirty_ops;

static bool translation_pre_enabled(struct intel_iommu *iommu)
{
        return (iommu->flags & VTD_FLAG_TRANS_PRE_ENABLED);
}

static void clear_translation_pre_enabled(struct intel_iommu *iommu)
{
        iommu->flags &= ~VTD_FLAG_TRANS_PRE_ENABLED;
}

static void init_translation_status(struct intel_iommu *iommu)
{
        u32 gsts;

        gsts = readl(iommu->reg + DMAR_GSTS_REG);
        if (gsts & DMA_GSTS_TES)
                iommu->flags |= VTD_FLAG_TRANS_PRE_ENABLED;
}

static int __init intel_iommu_setup(char *str)
{
        if (!str)
                return -EINVAL;

        while (*str) {
                if (!strncmp(str, "on", 2)) {
                        dmar_disabled = 0;
                        pr_info("IOMMU enabled\n");
                } else if (!strncmp(str, "off", 3)) {
                        dmar_disabled = 1;
                        no_platform_optin = 1;
                        pr_info("IOMMU disabled\n");
                } else if (!strncmp(str, "igfx_off", 8)) {
                        dmar_map_gfx = 0;
                        pr_info("Disable GFX device mapping\n");
                } else if (!strncmp(str, "forcedac", 8)) {
                        pr_warn("intel_iommu=forcedac deprecated; use iommu.forcedac instead\n");
                        iommu_dma_forcedac = true;
                } else if (!strncmp(str, "strict", 6)) {
                        pr_warn("intel_iommu=strict deprecated; use iommu.strict=1 instead\n");
                        iommu_set_dma_strict();
                } else if (!strncmp(str, "sp_off", 6)) {
                        pr_info("Disable supported super page\n");
                        intel_iommu_superpage = 0;
                } else if (!strncmp(str, "sm_on", 5)) {
                        pr_info("Enable scalable mode if hardware supports\n");
                        intel_iommu_sm = 1;
                } else if (!strncmp(str, "sm_off", 6)) {
                        pr_info("Scalable mode is disallowed\n");
                        intel_iommu_sm = 0;
                } else if (!strncmp(str, "tboot_noforce", 13)) {
                        pr_info("Intel-IOMMU: not forcing on after tboot. This could expose security risk for tboot\n");
                        intel_iommu_tboot_noforce = 1;
                } else {
                        pr_notice("Unknown option - '%s'\n", str);
                }

                str += strcspn(str, ",");
                while (*str == ',')
                        str++;
        }

        return 1;
}
__setup("intel_iommu=", intel_iommu_setup);

void *alloc_pgtable_page(int node, gfp_t gfp)
{
        struct page *page;
        void *vaddr = NULL;

        page = alloc_pages_node(node, gfp | __GFP_ZERO, 0);
        if (page)
                vaddr = page_address(page);
        return vaddr;
}

void free_pgtable_page(void *vaddr)
{
        free_page((unsigned long)vaddr);
}

static int domain_type_is_si(struct dmar_domain *domain)
{
        return domain->domain.type == IOMMU_DOMAIN_IDENTITY;
}

static int domain_pfn_supported(struct dmar_domain *domain, unsigned long pfn)
{
        int addr_width = agaw_to_width(domain->agaw) - VTD_PAGE_SHIFT;

        return !(addr_width < BITS_PER_LONG && pfn >> addr_width);
}

/*
 * Calculate the Supported Adjusted Guest Address Widths of an IOMMU.
 * Refer to 11.4.2 of the VT-d spec for the encoding of each bit of
 * the returned SAGAW.
 */
static unsigned long __iommu_calculate_sagaw(struct intel_iommu *iommu)
{
        unsigned long fl_sagaw, sl_sagaw;

        fl_sagaw = BIT(2) | (cap_fl5lp_support(iommu->cap) ? BIT(3) : 0);
        sl_sagaw = cap_sagaw(iommu->cap);

        /* Second level only. */
        if (!sm_supported(iommu) || !ecap_flts(iommu->ecap))
                return sl_sagaw;

        /* First level only. */
        if (!ecap_slts(iommu->ecap))
                return fl_sagaw;

        return fl_sagaw & sl_sagaw;
}

static int __iommu_calculate_agaw(struct intel_iommu *iommu, int max_gaw)
{
        unsigned long sagaw;
        int agaw;

        sagaw = __iommu_calculate_sagaw(iommu);
        for (agaw = width_to_agaw(max_gaw); agaw >= 0; agaw--) {
                if (test_bit(agaw, &sagaw))
                        break;
        }

        return agaw;
}

/*
 * Calculate max SAGAW for each iommu.
 */
int iommu_calculate_max_sagaw(struct intel_iommu *iommu)
{
        return __iommu_calculate_agaw(iommu, MAX_AGAW_WIDTH);
}

/*
 * calculate agaw for each iommu.
 * "SAGAW" may be different across iommus, use a default agaw, and
 * get a supported less agaw for iommus that don't support the default agaw.
 */
int iommu_calculate_agaw(struct intel_iommu *iommu)
{
        return __iommu_calculate_agaw(iommu, DEFAULT_DOMAIN_ADDRESS_WIDTH);
}

static bool iommu_paging_structure_coherency(struct intel_iommu *iommu)
{
        return sm_supported(iommu) ?
                        ecap_smpwc(iommu->ecap) : ecap_coherent(iommu->ecap);
}

static void domain_update_iommu_coherency(struct dmar_domain *domain)
{
        struct iommu_domain_info *info;
        struct dmar_drhd_unit *drhd;
        struct intel_iommu *iommu;
        bool found = false;
        unsigned long i;

        domain->iommu_coherency = true;
        xa_for_each(&domain->iommu_array, i, info) {
                found = true;
                if (!iommu_paging_structure_coherency(info->iommu)) {
                        domain->iommu_coherency = false;
                        break;
                }
        }
        if (found)
                return;

        /* No hardware attached; use lowest common denominator */
        rcu_read_lock();
        for_each_active_iommu(iommu, drhd) {
                if (!iommu_paging_structure_coherency(iommu)) {
                        domain->iommu_coherency = false;
                        break;
                }
        }
        rcu_read_unlock();
}

static int domain_update_iommu_superpage(struct dmar_domain *domain,
                                         struct intel_iommu *skip)
{
        struct dmar_drhd_unit *drhd;
        struct intel_iommu *iommu;
        int mask = 0x3;

        if (!intel_iommu_superpage)
                return 0;

        /* set iommu_superpage to the smallest common denominator */
        rcu_read_lock();
        for_each_active_iommu(iommu, drhd) {
                if (iommu != skip) {
                        if (domain && domain->use_first_level) {
                                if (!cap_fl1gp_support(iommu->cap))
                                        mask = 0x1;
                        } else {
                                mask &= cap_super_page_val(iommu->cap);
                        }

                        if (!mask)
                                break;
                }
        }
        rcu_read_unlock();

        return fls(mask);
}

static int domain_update_device_node(struct dmar_domain *domain)
{
        struct device_domain_info *info;
        int nid = NUMA_NO_NODE;
        unsigned long flags;

        spin_lock_irqsave(&domain->lock, flags);
        list_for_each_entry(info, &domain->devices, link) {
                /*
                 * There could possibly be multiple device numa nodes as devices
                 * within the same domain may sit behind different IOMMUs. There
                 * isn't perfect answer in such situation, so we select first
                 * come first served policy.
                 */
                nid = dev_to_node(info->dev);
                if (nid != NUMA_NO_NODE)
                        break;
        }
        spin_unlock_irqrestore(&domain->lock, flags);

        return nid;
}

/* Return the super pagesize bitmap if supported. */
static unsigned long domain_super_pgsize_bitmap(struct dmar_domain *domain)
{
        unsigned long bitmap = 0;

        /*
         * 1-level super page supports page size of 2MiB, 2-level super page
         * supports page size of both 2MiB and 1GiB.
         */
        if (domain->iommu_superpage == 1)
                bitmap |= SZ_2M;
        else if (domain->iommu_superpage == 2)
                bitmap |= SZ_2M | SZ_1G;

        return bitmap;
}

/* Some capabilities may be different across iommus */
void domain_update_iommu_cap(struct dmar_domain *domain)
{
        domain_update_iommu_coherency(domain);
        domain->iommu_superpage = domain_update_iommu_superpage(domain, NULL);

        /*
         * If RHSA is missing, we should default to the device numa domain
         * as fall back.
         */
        if (domain->nid == NUMA_NO_NODE)
                domain->nid = domain_update_device_node(domain);

        /*
         * First-level translation restricts the input-address to a
         * canonical address (i.e., address bits 63:N have the same
         * value as address bit [N-1], where N is 48-bits with 4-level
         * paging and 57-bits with 5-level paging). Hence, skip bit
         * [N-1].
         */
        if (domain->use_first_level)
                domain->domain.geometry.aperture_end = __DOMAIN_MAX_ADDR(domain->gaw - 1);
        else
                domain->domain.geometry.aperture_end = __DOMAIN_MAX_ADDR(domain->gaw);

        domain->domain.pgsize_bitmap |= domain_super_pgsize_bitmap(domain);
        domain_update_iotlb(domain);
}

struct context_entry *iommu_context_addr(struct intel_iommu *iommu, u8 bus,
                                         u8 devfn, int alloc)
{
        struct root_entry *root = &iommu->root_entry[bus];
        struct context_entry *context;
        u64 *entry;

        /*
         * Except that the caller requested to allocate a new entry,
         * returning a copied context entry makes no sense.
         */
        if (!alloc && context_copied(iommu, bus, devfn))
                return NULL;

        entry = &root->lo;
        if (sm_supported(iommu)) {
                if (devfn >= 0x80) {
                        devfn -= 0x80;
                        entry = &root->hi;
                }
                devfn *= 2;
        }
        if (*entry & 1)
                context = phys_to_virt(*entry & VTD_PAGE_MASK);
        else {
                unsigned long phy_addr;
                if (!alloc)
                        return NULL;

                context = alloc_pgtable_page(iommu->node, GFP_ATOMIC);
                if (!context)
                        return NULL;

                __iommu_flush_cache(iommu, (void *)context, CONTEXT_SIZE);
                phy_addr = virt_to_phys((void *)context);
                *entry = phy_addr | 1;
                __iommu_flush_cache(iommu, entry, sizeof(*entry));
        }
        return &context[devfn];
}

/**
 * is_downstream_to_pci_bridge - test if a device belongs to the PCI
 *                               sub-hierarchy of a candidate PCI-PCI bridge
 * @dev: candidate PCI device belonging to @bridge PCI sub-hierarchy
 * @bridge: the candidate PCI-PCI bridge
 *
 * Return: true if @dev belongs to @bridge PCI sub-hierarchy, else false.
 */
static bool
is_downstream_to_pci_bridge(struct device *dev, struct device *bridge)
{
        struct pci_dev *pdev, *pbridge;

        if (!dev_is_pci(dev) || !dev_is_pci(bridge))
                return false;

        pdev = to_pci_dev(dev);
        pbridge = to_pci_dev(bridge);

        if (pbridge->subordinate &&
            pbridge->subordinate->number <= pdev->bus->number &&
            pbridge->subordinate->busn_res.end >= pdev->bus->number)
                return true;

        return false;
}

static bool quirk_ioat_snb_local_iommu(struct pci_dev *pdev)
{
        struct dmar_drhd_unit *drhd;
        u32 vtbar;
        int rc;

        /* We know that this device on this chipset has its own IOMMU.
         * If we find it under a different IOMMU, then the BIOS is lying
         * to us. Hope that the IOMMU for this device is actually
         * disabled, and it needs no translation...
         */
        rc = pci_bus_read_config_dword(pdev->bus, PCI_DEVFN(0, 0), 0xb0, &vtbar);
        if (rc) {
                /* "can't" happen */
                dev_info(&pdev->dev, "failed to run vt-d quirk\n");
                return false;
        }
        vtbar &= 0xffff0000;

        /* we know that the this iommu should be at offset 0xa000 from vtbar */
        drhd = dmar_find_matched_drhd_unit(pdev);
        if (!drhd || drhd->reg_base_addr - vtbar != 0xa000) {
                pr_warn_once(FW_BUG "BIOS assigned incorrect VT-d unit for Intel(R) QuickData Technology device\n");
                add_taint(TAINT_FIRMWARE_WORKAROUND, LOCKDEP_STILL_OK);
                return true;
        }

        return false;
}

static bool iommu_is_dummy(struct intel_iommu *iommu, struct device *dev)
{
        if (!iommu || iommu->drhd->ignored)
                return true;

        if (dev_is_pci(dev)) {
                struct pci_dev *pdev = to_pci_dev(dev);

                if (pdev->vendor == PCI_VENDOR_ID_INTEL &&
                    pdev->device == PCI_DEVICE_ID_INTEL_IOAT_SNB &&
                    quirk_ioat_snb_local_iommu(pdev))
                        return true;
        }

        return false;
}

static struct intel_iommu *device_lookup_iommu(struct device *dev, u8 *bus, u8 *devfn)
{
        struct dmar_drhd_unit *drhd = NULL;
        struct pci_dev *pdev = NULL;
        struct intel_iommu *iommu;
        struct device *tmp;
        u16 segment = 0;
        int i;

        if (!dev)
                return NULL;

        if (dev_is_pci(dev)) {
                struct pci_dev *pf_pdev;

                pdev = pci_real_dma_dev(to_pci_dev(dev));

                /* VFs aren't listed in scope tables; we need to look up
                 * the PF instead to find the IOMMU. */
                pf_pdev = pci_physfn(pdev);
                dev = &pf_pdev->dev;
                segment = pci_domain_nr(pdev->bus);
        } else if (has_acpi_companion(dev))
                dev = &ACPI_COMPANION(dev)->dev;

        rcu_read_lock();
        for_each_iommu(iommu, drhd) {
                if (pdev && segment != drhd->segment)
                        continue;

                for_each_active_dev_scope(drhd->devices,
                                          drhd->devices_cnt, i, tmp) {
                        if (tmp == dev) {
                                /* For a VF use its original BDF# not that of the PF
                                 * which we used for the IOMMU lookup. Strictly speaking
                                 * we could do this for all PCI devices; we only need to
                                 * get the BDF# from the scope table for ACPI matches. */
                                if (pdev && pdev->is_virtfn)
                                        goto got_pdev;

                                if (bus && devfn) {
                                        *bus = drhd->devices[i].bus;
                                        *devfn = drhd->devices[i].devfn;
                                }
                                goto out;
                        }

                        if (is_downstream_to_pci_bridge(dev, tmp))
                                goto got_pdev;
                }

                if (pdev && drhd->include_all) {
got_pdev:
                        if (bus && devfn) {
                                *bus = pdev->bus->number;
                                *devfn = pdev->devfn;
                        }
                        goto out;
                }
        }
        iommu = NULL;
out:
        if (iommu_is_dummy(iommu, dev))
                iommu = NULL;

        rcu_read_unlock();

        return iommu;
}

static void domain_flush_cache(struct dmar_domain *domain,
                               void *addr, int size)
{
        if (!domain->iommu_coherency)
                clflush_cache_range(addr, size);
}

static void free_context_table(struct intel_iommu *iommu)
{
        struct context_entry *context;
        int i;

        if (!iommu->root_entry)
                return;

        for (i = 0; i < ROOT_ENTRY_NR; i++) {
                context = iommu_context_addr(iommu, i, 0, 0);
                if (context)
                        free_pgtable_page(context);

                if (!sm_supported(iommu))
                        continue;

                context = iommu_context_addr(iommu, i, 0x80, 0);
                if (context)
                        free_pgtable_page(context);
        }

        free_pgtable_page(iommu->root_entry);
        iommu->root_entry = NULL;
}

#ifdef CONFIG_DMAR_DEBUG
static void pgtable_walk(struct intel_iommu *iommu, unsigned long pfn,
                         u8 bus, u8 devfn, struct dma_pte *parent, int level)
{
        struct dma_pte *pte;
        int offset;

        while (1) {
                offset = pfn_level_offset(pfn, level);
                pte = &parent[offset];
                if (!pte || (dma_pte_superpage(pte) || !dma_pte_present(pte))) {
                        pr_info("PTE not present at level %d\n", level);
                        break;
                }

                pr_info("pte level: %d, pte value: 0x%016llx\n", level, pte->val);

                if (level == 1)
                        break;

                parent = phys_to_virt(dma_pte_addr(pte));
                level--;
        }
}

void dmar_fault_dump_ptes(struct intel_iommu *iommu, u16 source_id,
                          unsigned long long addr, u32 pasid)
{
        struct pasid_dir_entry *dir, *pde;
        struct pasid_entry *entries, *pte;
        struct context_entry *ctx_entry;
        struct root_entry *rt_entry;
        int i, dir_index, index, level;
        u8 devfn = source_id & 0xff;
        u8 bus = source_id >> 8;
        struct dma_pte *pgtable;

        pr_info("Dump %s table entries for IOVA 0x%llx\n", iommu->name, addr);

        /* root entry dump */
        rt_entry = &iommu->root_entry[bus];
        if (!rt_entry) {
                pr_info("root table entry is not present\n");
                return;
        }

        if (sm_supported(iommu))
                pr_info("scalable mode root entry: hi 0x%016llx, low 0x%016llx\n",
                        rt_entry->hi, rt_entry->lo);
        else
                pr_info("root entry: 0x%016llx", rt_entry->lo);

        /* context entry dump */
        ctx_entry = iommu_context_addr(iommu, bus, devfn, 0);
        if (!ctx_entry) {
                pr_info("context table entry is not present\n");
                return;
        }

        pr_info("context entry: hi 0x%016llx, low 0x%016llx\n",
                ctx_entry->hi, ctx_entry->lo);

        /* legacy mode does not require PASID entries */
        if (!sm_supported(iommu)) {
                level = agaw_to_level(ctx_entry->hi & 7);
                pgtable = phys_to_virt(ctx_entry->lo & VTD_PAGE_MASK);
                goto pgtable_walk;
        }

        /* get the pointer to pasid directory entry */
        dir = phys_to_virt(ctx_entry->lo & VTD_PAGE_MASK);
        if (!dir) {
                pr_info("pasid directory entry is not present\n");
                return;
        }
        /* For request-without-pasid, get the pasid from context entry */
        if (intel_iommu_sm && pasid == IOMMU_PASID_INVALID)
                pasid = IOMMU_NO_PASID;

        dir_index = pasid >> PASID_PDE_SHIFT;
        pde = &dir[dir_index];
        pr_info("pasid dir entry: 0x%016llx\n", pde->val);

        /* get the pointer to the pasid table entry */
        entries = get_pasid_table_from_pde(pde);
        if (!entries) {
                pr_info("pasid table entry is not present\n");
                return;
        }
        index = pasid & PASID_PTE_MASK;
        pte = &entries[index];
        for (i = 0; i < ARRAY_SIZE(pte->val); i++)
                pr_info("pasid table entry[%d]: 0x%016llx\n", i, pte->val[i]);

        if (pasid_pte_get_pgtt(pte) == PASID_ENTRY_PGTT_FL_ONLY) {
                level = pte->val[2] & BIT_ULL(2) ? 5 : 4;
                pgtable = phys_to_virt(pte->val[2] & VTD_PAGE_MASK);
        } else {
                level = agaw_to_level((pte->val[0] >> 2) & 0x7);
                pgtable = phys_to_virt(pte->val[0] & VTD_PAGE_MASK);
        }

pgtable_walk:
        pgtable_walk(iommu, addr >> VTD_PAGE_SHIFT, bus, devfn, pgtable, level);
}
#endif

static struct dma_pte *pfn_to_dma_pte(struct dmar_domain *domain,
                                      unsigned long pfn, int *target_level,
                                      gfp_t gfp)
{
        struct dma_pte *parent, *pte;
        int level = agaw_to_level(domain->agaw);
        int offset;

        if (!domain_pfn_supported(domain, pfn))
                /* Address beyond IOMMU's addressing capabilities. */
                return NULL;

        parent = domain->pgd;

        while (1) {
                void *tmp_page;

                offset = pfn_level_offset(pfn, level);
                pte = &parent[offset];
                if (!*target_level && (dma_pte_superpage(pte) || !dma_pte_present(pte)))
                        break;
                if (level == *target_level)
                        break;

                if (!dma_pte_present(pte)) {
                        uint64_t pteval;

                        tmp_page = alloc_pgtable_page(domain->nid, gfp);

                        if (!tmp_page)
                                return NULL;

                        domain_flush_cache(domain, tmp_page, VTD_PAGE_SIZE);
                        pteval = ((uint64_t)virt_to_dma_pfn(tmp_page) << VTD_PAGE_SHIFT) | DMA_PTE_READ | DMA_PTE_WRITE;
                        if (domain->use_first_level)
                                pteval |= DMA_FL_PTE_XD | DMA_FL_PTE_US | DMA_FL_PTE_ACCESS;

                        if (cmpxchg64(&pte->val, 0ULL, pteval))
                                /* Someone else set it while we were thinking; use theirs. */
                                free_pgtable_page(tmp_page);
                        else
                                domain_flush_cache(domain, pte, sizeof(*pte));
                }
                if (level == 1)
                        break;

                parent = phys_to_virt(dma_pte_addr(pte));
                level--;
        }

        if (!*target_level)
                *target_level = level;

        return pte;
}

/* return address's pte at specific level */
static struct dma_pte *dma_pfn_level_pte(struct dmar_domain *domain,
                                         unsigned long pfn,
                                         int level, int *large_page)
{
        struct dma_pte *parent, *pte;
        int total = agaw_to_level(domain->agaw);
        int offset;

        parent = domain->pgd;
        while (level <= total) {
                offset = pfn_level_offset(pfn, total);
                pte = &parent[offset];
                if (level == total)
                        return pte;

                if (!dma_pte_present(pte)) {
                        *large_page = total;
                        break;
                }

                if (dma_pte_superpage(pte)) {
                        *large_page = total;
                        return pte;
                }

                parent = phys_to_virt(dma_pte_addr(pte));
                total--;
        }
        return NULL;
}

/* clear last level pte, a tlb flush should be followed */
static void dma_pte_clear_range(struct dmar_domain *domain,
                                unsigned long start_pfn,
                                unsigned long last_pfn)
{
        unsigned int large_page;
        struct dma_pte *first_pte, *pte;

        if (WARN_ON(!domain_pfn_supported(domain, last_pfn)) ||
            WARN_ON(start_pfn > last_pfn))
                return;

        /* we don't need lock here; nobody else touches the iova range */
        do {
                large_page = 1;
                first_pte = pte = dma_pfn_level_pte(domain, start_pfn, 1, &large_page);
                if (!pte) {
                        start_pfn = align_to_level(start_pfn + 1, large_page + 1);
                        continue;
                }
                do {
                        dma_clear_pte(pte);
                        start_pfn += lvl_to_nr_pages(large_page);
                        pte++;
                } while (start_pfn <= last_pfn && !first_pte_in_page(pte));

                domain_flush_cache(domain, first_pte,
                                   (void *)pte - (void *)first_pte);

        } while (start_pfn && start_pfn <= last_pfn);
}

static void dma_pte_free_level(struct dmar_domain *domain, int level,
                               int retain_level, struct dma_pte *pte,
                               unsigned long pfn, unsigned long start_pfn,
                               unsigned long last_pfn)
{
        pfn = max(start_pfn, pfn);
        pte = &pte[pfn_level_offset(pfn, level)];

        do {
                unsigned long level_pfn;
                struct dma_pte *level_pte;

                if (!dma_pte_present(pte) || dma_pte_superpage(pte))
                        goto next;

                level_pfn = pfn & level_mask(level);
                level_pte = phys_to_virt(dma_pte_addr(pte));

                if (level > 2) {
                        dma_pte_free_level(domain, level - 1, retain_level,
                                           level_pte, level_pfn, start_pfn,
                                           last_pfn);
                }

                /*
                 * Free the page table if we're below the level we want to
                 * retain and the range covers the entire table.
                 */
                if (level < retain_level && !(start_pfn > level_pfn ||
                      last_pfn < level_pfn + level_size(level) - 1)) {
                        dma_clear_pte(pte);
                        domain_flush_cache(domain, pte, sizeof(*pte));
                        free_pgtable_page(level_pte);
                }
next:
                pfn += level_size(level);
        } while (!first_pte_in_page(++pte) && pfn <= last_pfn);
}

/*
 * clear last level (leaf) ptes and free page table pages below the
 * level we wish to keep intact.
 */
static void dma_pte_free_pagetable(struct dmar_domain *domain,
                                   unsigned long start_pfn,
                                   unsigned long last_pfn,
                                   int retain_level)
{
        dma_pte_clear_range(domain, start_pfn, last_pfn);

        /* We don't need lock here; nobody else touches the iova range */
        dma_pte_free_level(domain, agaw_to_level(domain->agaw), retain_level,
                           domain->pgd, 0, start_pfn, last_pfn);

        /* free pgd */
        if (start_pfn == 0 && last_pfn == DOMAIN_MAX_PFN(domain->gaw)) {
                free_pgtable_page(domain->pgd);
                domain->pgd = NULL;
        }
}

/* When a page at a given level is being unlinked from its parent, we don't
   need to *modify* it at all. All we need to do is make a list of all the
   pages which can be freed just as soon as we've flushed the IOTLB and we
   know the hardware page-walk will no longer touch them.
   The 'pte' argument is the *parent* PTE, pointing to the page that is to
   be freed. */
static void dma_pte_list_pagetables(struct dmar_domain *domain,
                                    int level, struct dma_pte *pte,
                                    struct list_head *freelist)
{
        struct page *pg;

        pg = pfn_to_page(dma_pte_addr(pte) >> PAGE_SHIFT);
        list_add_tail(&pg->lru, freelist);

        if (level == 1)
                return;

        pte = page_address(pg);
        do {
                if (dma_pte_present(pte) && !dma_pte_superpage(pte))
                        dma_pte_list_pagetables(domain, level - 1, pte, freelist);
                pte++;
        } while (!first_pte_in_page(pte));
}

static void dma_pte_clear_level(struct dmar_domain *domain, int level,
                                struct dma_pte *pte, unsigned long pfn,
                                unsigned long start_pfn, unsigned long last_pfn,
                                struct list_head *freelist)
{
        struct dma_pte *first_pte = NULL, *last_pte = NULL;

        pfn = max(start_pfn, pfn);
        pte = &pte[pfn_level_offset(pfn, level)];

        do {
                unsigned long level_pfn = pfn & level_mask(level);

                if (!dma_pte_present(pte))
                        goto next;

                /* If range covers entire pagetable, free it */
                if (start_pfn <= level_pfn &&
                    last_pfn >= level_pfn + level_size(level) - 1) {
                        /* These suborbinate page tables are going away entirely. Don't
                           bother to clear them; we're just going to *free* them. */
                        if (level > 1 && !dma_pte_superpage(pte))
                                dma_pte_list_pagetables(domain, level - 1, pte, freelist);

                        dma_clear_pte(pte);
                        if (!first_pte)
                                first_pte = pte;
                        last_pte = pte;
                } else if (level > 1) {
                        /* Recurse down into a level that isn't *entirely* obsolete */
                        dma_pte_clear_level(domain, level - 1,
                                            phys_to_virt(dma_pte_addr(pte)),
                                            level_pfn, start_pfn, last_pfn,
                                            freelist);
                }
next:
                pfn = level_pfn + level_size(level);
        } while (!first_pte_in_page(++pte) && pfn <= last_pfn);

        if (first_pte)
                domain_flush_cache(domain, first_pte,
                                   (void *)++last_pte - (void *)first_pte);
}

/* We can't just free the pages because the IOMMU may still be walking
   the page tables, and may have cached the intermediate levels. The
   pages can only be freed after the IOTLB flush has been done. */
static void domain_unmap(struct dmar_domain *domain, unsigned long start_pfn,
                         unsigned long last_pfn, struct list_head *freelist)
{
        if (WARN_ON(!domain_pfn_supported(domain, last_pfn)) ||
            WARN_ON(start_pfn > last_pfn))
                return;

        /* we don't need lock here; nobody else touches the iova range */
        dma_pte_clear_level(domain, agaw_to_level(domain->agaw),
                            domain->pgd, 0, start_pfn, last_pfn, freelist);

        /* free pgd */
        if (start_pfn == 0 && last_pfn == DOMAIN_MAX_PFN(domain->gaw)) {
                struct page *pgd_page = virt_to_page(domain->pgd);
                list_add_tail(&pgd_page->lru, freelist);
                domain->pgd = NULL;
        }
}

/* iommu handling */
static int iommu_alloc_root_entry(struct intel_iommu *iommu)
{
        struct root_entry *root;

        root = alloc_pgtable_page(iommu->node, GFP_ATOMIC);
        if (!root) {
                pr_err("Allocating root entry for %s failed\n",
                        iommu->name);
                return -ENOMEM;
        }

        __iommu_flush_cache(iommu, root, ROOT_SIZE);
        iommu->root_entry = root;

        return 0;
}

static void iommu_set_root_entry(struct intel_iommu *iommu)
{
        u64 addr;
        u32 sts;
        unsigned long flag;

        addr = virt_to_phys(iommu->root_entry);
        if (sm_supported(iommu))
                addr |= DMA_RTADDR_SMT;

        raw_spin_lock_irqsave(&iommu->register_lock, flag);
        dmar_writeq(iommu->reg + DMAR_RTADDR_REG, addr);

        writel(iommu->gcmd | DMA_GCMD_SRTP, iommu->reg + DMAR_GCMD_REG);

        /* Make sure hardware complete it */
        IOMMU_WAIT_OP(iommu, DMAR_GSTS_REG,
                      readl, (sts & DMA_GSTS_RTPS), sts);

        raw_spin_unlock_irqrestore(&iommu->register_lock, flag);

        /*
         * Hardware invalidates all DMA remapping hardware translation
         * caches as part of SRTP flow.
         */
        if (cap_esrtps(iommu->cap))
                return;

        iommu->flush.flush_context(iommu, 0, 0, 0, DMA_CCMD_GLOBAL_INVL);
        if (sm_supported(iommu))
                qi_flush_pasid_cache(iommu, 0, QI_PC_GLOBAL, 0);
        iommu->flush.flush_iotlb(iommu, 0, 0, 0, DMA_TLB_GLOBAL_FLUSH);
}

void iommu_flush_write_buffer(struct intel_iommu *iommu)
{
        u32 val;
        unsigned long flag;

        if (!rwbf_quirk && !cap_rwbf(iommu->cap))
                return;

        raw_spin_lock_irqsave(&iommu->register_lock, flag);
        writel(iommu->gcmd | DMA_GCMD_WBF, iommu->reg + DMAR_GCMD_REG);

        /* Make sure hardware complete it */
        IOMMU_WAIT_OP(iommu, DMAR_GSTS_REG,
                      readl, (!(val & DMA_GSTS_WBFS)), val);

        raw_spin_unlock_irqrestore(&iommu->register_lock, flag);
}

/* return value determine if we need a write buffer flush */
static void __iommu_flush_context(struct intel_iommu *iommu,
                                  u16 did, u16 source_id, u8 function_mask,
                                  u64 type)
{
        u64 val = 0;
        unsigned long flag;

        switch (type) {
        case DMA_CCMD_GLOBAL_INVL:
                val = DMA_CCMD_GLOBAL_INVL;
                break;
        case DMA_CCMD_DOMAIN_INVL:
                val = DMA_CCMD_DOMAIN_INVL|DMA_CCMD_DID(did);
                break;
        case DMA_CCMD_DEVICE_INVL:
                val = DMA_CCMD_DEVICE_INVL|DMA_CCMD_DID(did)
                        | DMA_CCMD_SID(source_id) | DMA_CCMD_FM(function_mask);
                break;
        default:
                pr_warn("%s: Unexpected context-cache invalidation type 0x%llx\n",
                        iommu->name, type);
                return;
        }
        val |= DMA_CCMD_ICC;

        raw_spin_lock_irqsave(&iommu->register_lock, flag);
        dmar_writeq(iommu->reg + DMAR_CCMD_REG, val);

        /* Make sure hardware complete it */
        IOMMU_WAIT_OP(iommu, DMAR_CCMD_REG,
                dmar_readq, (!(val & DMA_CCMD_ICC)), val);

        raw_spin_unlock_irqrestore(&iommu->register_lock, flag);
}

/* return value determine if we need a write buffer flush */
static void __iommu_flush_iotlb(struct intel_iommu *iommu, u16 did,
                                u64 addr, unsigned int size_order, u64 type)
{
        int tlb_offset = ecap_iotlb_offset(iommu->ecap);
        u64 val = 0, val_iva = 0;
        unsigned long flag;

        switch (type) {
        case DMA_TLB_GLOBAL_FLUSH:
                /* global flush doesn't need set IVA_REG */
                val = DMA_TLB_GLOBAL_FLUSH|DMA_TLB_IVT;
                break;
        case DMA_TLB_DSI_FLUSH:
                val = DMA_TLB_DSI_FLUSH|DMA_TLB_IVT|DMA_TLB_DID(did);
                break;
        case DMA_TLB_PSI_FLUSH:
                val = DMA_TLB_PSI_FLUSH|DMA_TLB_IVT|DMA_TLB_DID(did);
                /* IH bit is passed in as part of address */
                val_iva = size_order | addr;
                break;
        default:
                pr_warn("%s: Unexpected iotlb invalidation type 0x%llx\n",
                        iommu->name, type);
                return;
        }

        if (cap_write_drain(iommu->cap))
                val |= DMA_TLB_WRITE_DRAIN;

        raw_spin_lock_irqsave(&iommu->register_lock, flag);
        /* Note: Only uses first TLB reg currently */
        if (val_iva)
                dmar_writeq(iommu->reg + tlb_offset, val_iva);
        dmar_writeq(iommu->reg + tlb_offset + 8, val);

        /* Make sure hardware complete it */
        IOMMU_WAIT_OP(iommu, tlb_offset + 8,
                dmar_readq, (!(val & DMA_TLB_IVT)), val);

        raw_spin_unlock_irqrestore(&iommu->register_lock, flag);

        /* check IOTLB invalidation granularity */
        if (DMA_TLB_IAIG(val) == 0)
                pr_err("Flush IOTLB failed\n");
        if (DMA_TLB_IAIG(val) != DMA_TLB_IIRG(type))
                pr_debug("TLB flush request %Lx, actual %Lx\n",
                        (unsigned long long)DMA_TLB_IIRG(type),
                        (unsigned long long)DMA_TLB_IAIG(val));
}

static struct device_domain_info *
domain_lookup_dev_info(struct dmar_domain *domain,
                       struct intel_iommu *iommu, u8 bus, u8 devfn)
{
        struct device_domain_info *info;
        unsigned long flags;

        spin_lock_irqsave(&domain->lock, flags);
        list_for_each_entry(info, &domain->devices, link) {
                if (info->iommu == iommu && info->bus == bus &&
                    info->devfn == devfn) {
                        spin_unlock_irqrestore(&domain->lock, flags);
                        return info;
                }
        }
        spin_unlock_irqrestore(&domain->lock, flags);

        return NULL;
}

void domain_update_iotlb(struct dmar_domain *domain)
{
        struct dev_pasid_info *dev_pasid;
        struct device_domain_info *info;
        bool has_iotlb_device = false;
        unsigned long flags;

        spin_lock_irqsave(&domain->lock, flags);
        list_for_each_entry(info, &domain->devices, link) {
                if (info->ats_enabled) {
                        has_iotlb_device = true;
                        break;
                }
        }

        list_for_each_entry(dev_pasid, &domain->dev_pasids, link_domain) {
                info = dev_iommu_priv_get(dev_pasid->dev);
                if (info->ats_enabled) {
                        has_iotlb_device = true;
                        break;
                }
        }
        domain->has_iotlb_device = has_iotlb_device;
        spin_unlock_irqrestore(&domain->lock, flags);
}

/*
 * The extra devTLB flush quirk impacts those QAT devices with PCI device
 * IDs ranging from 0x4940 to 0x4943. It is exempted from risky_device()
 * check because it applies only to the built-in QAT devices and it doesn't
 * grant additional privileges.
 */
#define BUGGY_QAT_DEVID_MASK 0x4940
static bool dev_needs_extra_dtlb_flush(struct pci_dev *pdev)
{
        if (pdev->vendor != PCI_VENDOR_ID_INTEL)
                return false;

        if ((pdev->device & 0xfffc) != BUGGY_QAT_DEVID_MASK)
                return false;

        return true;
}

static void iommu_enable_pci_caps(struct device_domain_info *info)
{
        struct pci_dev *pdev;

        if (!dev_is_pci(info->dev))
                return;

        pdev = to_pci_dev(info->dev);

        /* The PCIe spec, in its wisdom, declares that the behaviour of
           the device if you enable PASID support after ATS support is
           undefined. So always enable PASID support on devices which
           have it, even if we can't yet know if we're ever going to
           use it. */
        if (info->pasid_supported && !pci_enable_pasid(pdev, info->pasid_supported & ~1))
                info->pasid_enabled = 1;

        if (info->ats_supported && pci_ats_page_aligned(pdev) &&
            !pci_enable_ats(pdev, VTD_PAGE_SHIFT)) {
                info->ats_enabled = 1;
                domain_update_iotlb(info->domain);
        }
}

static void iommu_disable_pci_caps(struct device_domain_info *info)
{
        struct pci_dev *pdev;

        if (!dev_is_pci(info->dev))
                return;

        pdev = to_pci_dev(info->dev);

        if (info->ats_enabled) {
                pci_disable_ats(pdev);
                info->ats_enabled = 0;
                domain_update_iotlb(info->domain);
        }

        if (info->pasid_enabled) {
                pci_disable_pasid(pdev);
                info->pasid_enabled = 0;
        }
}

static void __iommu_flush_dev_iotlb(struct device_domain_info *info,
                                    u64 addr, unsigned int mask)
{
        u16 sid, qdep;

        if (!info || !info->ats_enabled)
                return;

        sid = info->bus << 8 | info->devfn;
        qdep = info->ats_qdep;
        qi_flush_dev_iotlb(info->iommu, sid, info->pfsid,
                           qdep, addr, mask);
        quirk_extra_dev_tlb_flush(info, addr, mask, IOMMU_NO_PASID, qdep);
}

static void iommu_flush_dev_iotlb(struct dmar_domain *domain,
                                  u64 addr, unsigned mask)
{
        struct dev_pasid_info *dev_pasid;
        struct device_domain_info *info;
        unsigned long flags;

        if (!domain->has_iotlb_device)
                return;

        spin_lock_irqsave(&domain->lock, flags);
        list_for_each_entry(info, &domain->devices, link)
                __iommu_flush_dev_iotlb(info, addr, mask);

        list_for_each_entry(dev_pasid, &domain->dev_pasids, link_domain) {
                info = dev_iommu_priv_get(dev_pasid->dev);

                if (!info->ats_enabled)
                        continue;

                qi_flush_dev_iotlb_pasid(info->iommu,
                                         PCI_DEVID(info->bus, info->devfn),
                                         info->pfsid, dev_pasid->pasid,
                                         info->ats_qdep, addr,
                                         mask);
        }
        spin_unlock_irqrestore(&domain->lock, flags);
}

static void domain_flush_pasid_iotlb(struct intel_iommu *iommu,
                                     struct dmar_domain *domain, u64 addr,
                                     unsigned long npages, bool ih)
{
        u16 did = domain_id_iommu(domain, iommu);
        struct dev_pasid_info *dev_pasid;
        unsigned long flags;

        spin_lock_irqsave(&domain->lock, flags);
        list_for_each_entry(dev_pasid, &domain->dev_pasids, link_domain)
                qi_flush_piotlb(iommu, did, dev_pasid->pasid, addr, npages, ih);

        if (!list_empty(&domain->devices))
                qi_flush_piotlb(iommu, did, IOMMU_NO_PASID, addr, npages, ih);
        spin_unlock_irqrestore(&domain->lock, flags);
}

static void __iommu_flush_iotlb_psi(struct intel_iommu *iommu, u16 did,
                                    unsigned long pfn, unsigned int pages,
                                    int ih)
{
        unsigned int aligned_pages = __roundup_pow_of_two(pages);
        unsigned long bitmask = aligned_pages - 1;
        unsigned int mask = ilog2(aligned_pages);
        u64 addr = (u64)pfn << VTD_PAGE_SHIFT;

        /*
         * PSI masks the low order bits of the base address. If the
         * address isn't aligned to the mask, then compute a mask value
         * needed to ensure the target range is flushed.
         */
        if (unlikely(bitmask & pfn)) {
                unsigned long end_pfn = pfn + pages - 1, shared_bits;

                /*
                 * Since end_pfn <= pfn + bitmask, the only way bits
                 * higher than bitmask can differ in pfn and end_pfn is
                 * by carrying. This means after masking out bitmask,
                 * high bits starting with the first set bit in
                 * shared_bits are all equal in both pfn and end_pfn.
                 */
                shared_bits = ~(pfn ^ end_pfn) & ~bitmask;
                mask = shared_bits ? __ffs(shared_bits) : BITS_PER_LONG;
        }

        /*
         * Fallback to domain selective flush if no PSI support or
         * the size is too big.
         */
        if (!cap_pgsel_inv(iommu->cap) || mask > cap_max_amask_val(iommu->cap))
                iommu->flush.flush_iotlb(iommu, did, 0, 0,
                                         DMA_TLB_DSI_FLUSH);
        else
                iommu->flush.flush_iotlb(iommu, did, addr | ih, mask,
                                         DMA_TLB_PSI_FLUSH);
}

static void iommu_flush_iotlb_psi(struct intel_iommu *iommu,
                                  struct dmar_domain *domain,
                                  unsigned long pfn, unsigned int pages,
                                  int ih, int map)
{
        unsigned int aligned_pages = __roundup_pow_of_two(pages);
        unsigned int mask = ilog2(aligned_pages);
        uint64_t addr = (uint64_t)pfn << VTD_PAGE_SHIFT;
        u16 did = domain_id_iommu(domain, iommu);

        if (WARN_ON(!pages))
                return;

        if (ih)
                ih = 1 << 6;

        if (domain->use_first_level)
                domain_flush_pasid_iotlb(iommu, domain, addr, pages, ih);
        else
                __iommu_flush_iotlb_psi(iommu, did, pfn, pages, ih);

        /*
         * In caching mode, changes of pages from non-present to present require
         * flush. However, device IOTLB doesn't need to be flushed in this case.
         */
        if (!cap_caching_mode(iommu->cap) || !map)
                iommu_flush_dev_iotlb(domain, addr, mask);
}

/* Notification for newly created mappings */
static void __mapping_notify_one(struct intel_iommu *iommu, struct dmar_domain *domain,
                                 unsigned long pfn, unsigned int pages)
{
        /*
         * It's a non-present to present mapping. Only flush if caching mode
         * and second level.
         */
        if (cap_caching_mode(iommu->cap) && !domain->use_first_level)
                iommu_flush_iotlb_psi(iommu, domain, pfn, pages, 0, 1);
        else
                iommu_flush_write_buffer(iommu);
}

/*
 * Flush the relevant caches in nested translation if the domain
 * also serves as a parent
 */
static void parent_domain_flush(struct dmar_domain *domain,
                                unsigned long pfn,
                                unsigned long pages, int ih)
{
        struct dmar_domain *s1_domain;

        spin_lock(&domain->s1_lock);
        list_for_each_entry(s1_domain, &domain->s1_domains, s2_link) {
                struct device_domain_info *device_info;
                struct iommu_domain_info *info;
                unsigned long flags;
                unsigned long i;

                xa_for_each(&s1_domain->iommu_array, i, info)
                        __iommu_flush_iotlb_psi(info->iommu, info->did,
                                                pfn, pages, ih);

                if (!s1_domain->has_iotlb_device)
                        continue;

                spin_lock_irqsave(&s1_domain->lock, flags);
                list_for_each_entry(device_info, &s1_domain->devices, link)
                        /*
                         * Address translation cache in device side caches the
                         * result of nested translation. There is no easy way
                         * to identify the exact set of nested translations
                         * affected by a change in S2. So just flush the entire
                         * device cache.
                         */
                        __iommu_flush_dev_iotlb(device_info, 0,
                                                MAX_AGAW_PFN_WIDTH);
                spin_unlock_irqrestore(&s1_domain->lock, flags);
        }
        spin_unlock(&domain->s1_lock);
}

static void intel_flush_iotlb_all(struct iommu_domain *domain)
{
        struct dmar_domain *dmar_domain = to_dmar_domain(domain);
        struct iommu_domain_info *info;
        unsigned long idx;

        xa_for_each(&dmar_domain->iommu_array, idx, info) {
                struct intel_iommu *iommu = info->iommu;
                u16 did = domain_id_iommu(dmar_domain, iommu);

                if (dmar_domain->use_first_level)
                        domain_flush_pasid_iotlb(iommu, dmar_domain, 0, -1, 0);
                else
                        iommu->flush.flush_iotlb(iommu, did, 0, 0,
                                                 DMA_TLB_DSI_FLUSH);

                if (!cap_caching_mode(iommu->cap))
                        iommu_flush_dev_iotlb(dmar_domain, 0, MAX_AGAW_PFN_WIDTH);
        }

        if (dmar_domain->nested_parent)
                parent_domain_flush(dmar_domain, 0, -1, 0);
}

static void iommu_disable_protect_mem_regions(struct intel_iommu *iommu)
{
        u32 pmen;
        unsigned long flags;

        if (!cap_plmr(iommu->cap) && !cap_phmr(iommu->cap))
                return;

        raw_spin_lock_irqsave(&iommu->register_lock, flags);
        pmen = readl(iommu->reg + DMAR_PMEN_REG);
        pmen &= ~DMA_PMEN_EPM;
        writel(pmen, iommu->reg + DMAR_PMEN_REG);

        /* wait for the protected region status bit to clear */
        IOMMU_WAIT_OP(iommu, DMAR_PMEN_REG,
                readl, !(pmen & DMA_PMEN_PRS), pmen);

        raw_spin_unlock_irqrestore(&iommu->register_lock, flags);
}

static void iommu_enable_translation(struct intel_iommu *iommu)
{
        u32 sts;
        unsigned long flags;

        raw_spin_lock_irqsave(&iommu->register_lock, flags);
        iommu->gcmd |= DMA_GCMD_TE;
        writel(iommu->gcmd, iommu->reg + DMAR_GCMD_REG);

        /* Make sure hardware complete it */
        IOMMU_WAIT_OP(iommu, DMAR_GSTS_REG,
                      readl, (sts & DMA_GSTS_TES), sts);

        raw_spin_unlock_irqrestore(&iommu->register_lock, flags);
}

static void iommu_disable_translation(struct intel_iommu *iommu)
{
        u32 sts;
        unsigned long flag;

        if (iommu_skip_te_disable && iommu->drhd->gfx_dedicated &&
            (cap_read_drain(iommu->cap) || cap_write_drain(iommu->cap)))
                return;

        raw_spin_lock_irqsave(&iommu->register_lock, flag);
        iommu->gcmd &= ~DMA_GCMD_TE;
        writel(iommu->gcmd, iommu->reg + DMAR_GCMD_REG);

        /* Make sure hardware complete it */
        IOMMU_WAIT_OP(iommu, DMAR_GSTS_REG,
                      readl, (!(sts & DMA_GSTS_TES)), sts);

        raw_spin_unlock_irqrestore(&iommu->register_lock, flag);
}

static int iommu_init_domains(struct intel_iommu *iommu)
{
        u32 ndomains;

        ndomains = cap_ndoms(iommu->cap);
        pr_debug("%s: Number of Domains supported <%d>\n",
                 iommu->name, ndomains);

        spin_lock_init(&iommu->lock);

        iommu->domain_ids = bitmap_zalloc(ndomains, GFP_KERNEL);
        if (!iommu->domain_ids)
                return -ENOMEM;

        /*
         * If Caching mode is set, then invalid translations are tagged
         * with domain-id 0, hence we need to pre-allocate it. We also
         * use domain-id 0 as a marker for non-allocated domain-id, so
         * make sure it is not used for a real domain.
         */
        set_bit(0, iommu->domain_ids);

        /*
         * Vt-d spec rev3.0 (section 6.2.3.1) requires that each pasid
         * entry for first-level or pass-through translation modes should
         * be programmed with a domain id different from those used for
         * second-level or nested translation. We reserve a domain id for
         * this purpose.
         */
        if (sm_supported(iommu))
                set_bit(FLPT_DEFAULT_DID, iommu->domain_ids);

        return 0;
}

static void disable_dmar_iommu(struct intel_iommu *iommu)
{
        if (!iommu->domain_ids)
                return;

        /*
         * All iommu domains must have been detached from the devices,
         * hence there should be no domain IDs in use.
         */
        if (WARN_ON(bitmap_weight(iommu->domain_ids, cap_ndoms(iommu->cap))
                    > NUM_RESERVED_DID))
                return;

        if (iommu->gcmd & DMA_GCMD_TE)
                iommu_disable_translation(iommu);
}

static void free_dmar_iommu(struct intel_iommu *iommu)
{
        if (iommu->domain_ids) {
                bitmap_free(iommu->domain_ids);
                iommu->domain_ids = NULL;
        }

        if (iommu->copied_tables) {
                bitmap_free(iommu->copied_tables);
                iommu->copied_tables = NULL;
        }

        /* free context mapping */
        free_context_table(iommu);

#ifdef CONFIG_INTEL_IOMMU_SVM
        if (pasid_supported(iommu)) {
                if (ecap_prs(iommu->ecap))
                        intel_svm_finish_prq(iommu);
        }
#endif
}

/*
 * Check and return whether first level is used by default for
 * DMA translation.
 */
static bool first_level_by_default(unsigned int type)
{
        /* Only SL is available in legacy mode */
        if (!scalable_mode_support())
                return false;

        /* Only level (either FL or SL) is available, just use it */
        if (intel_cap_flts_sanity() ^ intel_cap_slts_sanity())
                return intel_cap_flts_sanity();

        /* Both levels are available, decide it based on domain type */
        return type != IOMMU_DOMAIN_UNMANAGED;
}

static struct dmar_domain *alloc_domain(unsigned int type)
{
        struct dmar_domain *domain;

        domain = kzalloc(sizeof(*domain), GFP_KERNEL);
        if (!domain)
                return NULL;

        domain->nid = NUMA_NO_NODE;
        if (first_level_by_default(type))
                domain->use_first_level = true;
        domain->has_iotlb_device = false;
        INIT_LIST_HEAD(&domain->devices);
        INIT_LIST_HEAD(&domain->dev_pasids);
        spin_lock_init(&domain->lock);
        xa_init(&domain->iommu_array);

        return domain;
}

int domain_attach_iommu(struct dmar_domain *domain, struct intel_iommu *iommu)
{
        struct iommu_domain_info *info, *curr;
        unsigned long ndomains;
        int num, ret = -ENOSPC;

        info = kzalloc(sizeof(*info), GFP_KERNEL);
        if (!info)
                return -ENOMEM;

        spin_lock(&iommu->lock);
        curr = xa_load(&domain->iommu_array, iommu->seq_id);
        if (curr) {
                curr->refcnt++;
                spin_unlock(&iommu->lock);
                kfree(info);
                return 0;
        }

        ndomains = cap_ndoms(iommu->cap);
        num = find_first_zero_bit(iommu->domain_ids, ndomains);
        if (num >= ndomains) {
                pr_err("%s: No free domain ids\n", iommu->name);
                goto err_unlock;
        }

        set_bit(num, iommu->domain_ids);
        info->refcnt    = 1;
        info->did       = num;
        info->iommu     = iommu;
        curr = xa_cmpxchg(&domain->iommu_array, iommu->seq_id,
                          NULL, info, GFP_ATOMIC);
        if (curr) {
                ret = xa_err(curr) ? : -EBUSY;
                goto err_clear;
        }
        domain_update_iommu_cap(domain);

        spin_unlock(&iommu->lock);
        return 0;

err_clear:
        clear_bit(info->did, iommu->domain_ids);
err_unlock:
        spin_unlock(&iommu->lock);
        kfree(info);
        return ret;
}

void domain_detach_iommu(struct dmar_domain *domain, struct intel_iommu *iommu)
{
        struct iommu_domain_info *info;

        spin_lock(&iommu->lock);
        info = xa_load(&domain->iommu_array, iommu->seq_id);
        if (--info->refcnt == 0) {
                clear_bit(info->did, iommu->domain_ids);
                xa_erase(&domain->iommu_array, iommu->seq_id);
                domain->nid = NUMA_NO_NODE;
                domain_update_iommu_cap(domain);
                kfree(info);
        }
        spin_unlock(&iommu->lock);
}

static int guestwidth_to_adjustwidth(int gaw)
{
        int agaw;
        int r = (gaw - 12) % 9;

        if (r == 0)
                agaw = gaw;
        else
                agaw = gaw + 9 - r;
        if (agaw > 64)
                agaw = 64;
        return agaw;
}

static void domain_exit(struct dmar_domain *domain)
{
        if (domain->pgd) {
                LIST_HEAD(freelist);

                domain_unmap(domain, 0, DOMAIN_MAX_PFN(domain->gaw), &freelist);
                put_pages_list(&freelist);
        }

        if (WARN_ON(!list_empty(&domain->devices)))
                return;

        kfree(domain);
}

static int domain_context_mapping_one(struct dmar_domain *domain,
                                      struct intel_iommu *iommu,
                                      u8 bus, u8 devfn)
{
        struct device_domain_info *info =
                        domain_lookup_dev_info(domain, iommu, bus, devfn);
        u16 did = domain_id_iommu(domain, iommu);
        int translation = CONTEXT_TT_MULTI_LEVEL;
        struct dma_pte *pgd = domain->pgd;
        struct context_entry *context;
        int agaw, ret;

        if (hw_pass_through && domain_type_is_si(domain))
                translation = CONTEXT_TT_PASS_THROUGH;

        pr_debug("Set context mapping for %02x:%02x.%d\n",
                bus, PCI_SLOT(devfn), PCI_FUNC(devfn));

        spin_lock(&iommu->lock);
        ret = -ENOMEM;
        context = iommu_context_addr(iommu, bus, devfn, 1);
        if (!context)
                goto out_unlock;

        ret = 0;
        if (context_present(context) && !context_copied(iommu, bus, devfn))
                goto out_unlock;

        /*
         * For kdump cases, old valid entries may be cached due to the
         * in-flight DMA and copied pgtable, but there is no unmapping
         * behaviour for them, thus we need an explicit cache flush for
         * the newly-mapped device. For kdump, at this point, the device
         * is supposed to finish reset at its driver probe stage, so no
         * in-flight DMA will exist, and we don't need to worry anymore
         * hereafter.
         */
        if (context_copied(iommu, bus, devfn)) {
                u16 did_old = context_domain_id(context);

                if (did_old < cap_ndoms(iommu->cap)) {
                        iommu->flush.flush_context(iommu, did_old,
                                                   (((u16)bus) << 8) | devfn,
                                                   DMA_CCMD_MASK_NOBIT,
                                                   DMA_CCMD_DEVICE_INVL);
                        iommu->flush.flush_iotlb(iommu, did_old, 0, 0,
                                                 DMA_TLB_DSI_FLUSH);
                }

                clear_context_copied(iommu, bus, devfn);
        }

        context_clear_entry(context);
        context_set_domain_id(context, did);

        if (translation != CONTEXT_TT_PASS_THROUGH) {
                /*
                 * Skip top levels of page tables for iommu which has
                 * less agaw than default. Unnecessary for PT mode.
                 */
                for (agaw = domain->agaw; agaw > iommu->agaw; agaw--) {
                        ret = -ENOMEM;
                        pgd = phys_to_virt(dma_pte_addr(pgd));
                        if (!dma_pte_present(pgd))
                                goto out_unlock;
                }

                if (info && info->ats_supported)
                        translation = CONTEXT_TT_DEV_IOTLB;
                else
                        translation = CONTEXT_TT_MULTI_LEVEL;

                context_set_address_root(context, virt_to_phys(pgd));
                context_set_address_width(context, agaw);
        } else {
                /*
                 * In pass through mode, AW must be programmed to
                 * indicate the largest AGAW value supported by
                 * hardware. And ASR is ignored by hardware.
                 */
                context_set_address_width(context, iommu->msagaw);
        }

        context_set_translation_type(context, translation);
        context_set_fault_enable(context);
        context_set_present(context);
        if (!ecap_coherent(iommu->ecap))
                clflush_cache_range(context, sizeof(*context));

        /*
         * It's a non-present to present mapping. If hardware doesn't cache
         * non-present entry we only need to flush the write-buffer. If the
         * _does_ cache non-present entries, then it does so in the special
         * domain #0, which we have to flush:
         */
        if (cap_caching_mode(iommu->cap)) {
                iommu->flush.flush_context(iommu, 0,
                                           (((u16)bus) << 8) | devfn,
                                           DMA_CCMD_MASK_NOBIT,
                                           DMA_CCMD_DEVICE_INVL);
                iommu->flush.flush_iotlb(iommu, did, 0, 0, DMA_TLB_DSI_FLUSH);
        } else {
                iommu_flush_write_buffer(iommu);
        }

        ret = 0;

out_unlock:
        spin_unlock(&iommu->lock);

        return ret;
}

static int domain_context_mapping_cb(struct pci_dev *pdev,
                                     u16 alias, void *opaque)
{
        struct device_domain_info *info = dev_iommu_priv_get(&pdev->dev);
        struct intel_iommu *iommu = info->iommu;
        struct dmar_domain *domain = opaque;

        return domain_context_mapping_one(domain, iommu,
                                          PCI_BUS_NUM(alias), alias & 0xff);
}

static int
domain_context_mapping(struct dmar_domain *domain, struct device *dev)
{
        struct device_domain_info *info = dev_iommu_priv_get(dev);
        struct intel_iommu *iommu = info->iommu;
        u8 bus = info->bus, devfn = info->devfn;

        if (!dev_is_pci(dev))
                return domain_context_mapping_one(domain, iommu, bus, devfn);

        return pci_for_each_dma_alias(to_pci_dev(dev),
                                      domain_context_mapping_cb, domain);
}

/* Returns a number of VTD pages, but aligned to MM page size */
static unsigned long aligned_nrpages(unsigned long host_addr, size_t size)
{
        host_addr &= ~PAGE_MASK;
        return PAGE_ALIGN(host_addr + size) >> VTD_PAGE_SHIFT;
}

/* Return largest possible superpage level for a given mapping */
static int hardware_largepage_caps(struct dmar_domain *domain, unsigned long iov_pfn,
                                   unsigned long phy_pfn, unsigned long pages)
{
        int support, level = 1;
        unsigned long pfnmerge;

        support = domain->iommu_superpage;

        /* To use a large page, the virtual *and* physical addresses
           must be aligned to 2MiB/1GiB/etc. Lower bits set in either
           of them will mean we have to use smaller pages. So just
           merge them and check both at once. */
        pfnmerge = iov_pfn | phy_pfn;

        while (support && !(pfnmerge & ~VTD_STRIDE_MASK)) {
                pages >>= VTD_STRIDE_SHIFT;
                if (!pages)
                        break;
                pfnmerge >>= VTD_STRIDE_SHIFT;
                level++;
                support--;
        }
        return level;
}

/*
 * Ensure that old small page tables are removed to make room for superpage(s).
 * We're going to add new large pages, so make sure we don't remove their parent
 * tables. The IOTLB/devTLBs should be flushed if any PDE/PTEs are cleared.
 */
static void switch_to_super_page(struct dmar_domain *domain,
                                 unsigned long start_pfn,
                                 unsigned long end_pfn, int level)
{
        unsigned long lvl_pages = lvl_to_nr_pages(level);
        struct iommu_domain_info *info;
        struct dma_pte *pte = NULL;
        unsigned long i;

        while (start_pfn <= end_pfn) {
                if (!pte)
                        pte = pfn_to_dma_pte(domain, start_pfn, &level,
                                             GFP_ATOMIC);

                if (dma_pte_present(pte)) {
                        dma_pte_free_pagetable(domain, start_pfn,
                                               start_pfn + lvl_pages - 1,
                                               level + 1);

                        xa_for_each(&domain->iommu_array, i, info)
                                iommu_flush_iotlb_psi(info->iommu, domain,
                                                      start_pfn, lvl_pages,
                                                      0, 0);
                        if (domain->nested_parent)
                                parent_domain_flush(domain, start_pfn,
                                                    lvl_pages, 0);
                }

                pte++;
                start_pfn += lvl_pages;
                if (first_pte_in_page(pte))
                        pte = NULL;
        }
}

static int
__domain_mapping(struct dmar_domain *domain, unsigned long iov_pfn,
                 unsigned long phys_pfn, unsigned long nr_pages, int prot,
                 gfp_t gfp)
{
        struct dma_pte *first_pte = NULL, *pte = NULL;
        unsigned int largepage_lvl = 0;
        unsigned long lvl_pages = 0;
        phys_addr_t pteval;
        u64 attr;

        if (unlikely(!domain_pfn_supported(domain, iov_pfn + nr_pages - 1)))
                return -EINVAL;

        if ((prot & (DMA_PTE_READ|DMA_PTE_WRITE)) == 0)
                return -EINVAL;

        if (!(prot & DMA_PTE_WRITE) && domain->nested_parent) {
                pr_err_ratelimited("Read-only mapping is disallowed on the domain which serves as the parent in a nested configuration, due to HW errata (ERRATA_772415_SPR17)\n");
                return -EINVAL;
        }

        attr = prot & (DMA_PTE_READ | DMA_PTE_WRITE | DMA_PTE_SNP);
        attr |= DMA_FL_PTE_PRESENT;
        if (domain->use_first_level) {
                attr |= DMA_FL_PTE_XD | DMA_FL_PTE_US | DMA_FL_PTE_ACCESS;
                if (prot & DMA_PTE_WRITE)
                        attr |= DMA_FL_PTE_DIRTY;
        }

        domain->has_mappings = true;

        pteval = ((phys_addr_t)phys_pfn << VTD_PAGE_SHIFT) | attr;

        while (nr_pages > 0) {
                uint64_t tmp;

                if (!pte) {
                        largepage_lvl = hardware_largepage_caps(domain, iov_pfn,
                                        phys_pfn, nr_pages);

                        pte = pfn_to_dma_pte(domain, iov_pfn, &largepage_lvl,
                                             gfp);
                        if (!pte)
                                return -ENOMEM;
                        first_pte = pte;

                        lvl_pages = lvl_to_nr_pages(largepage_lvl);

                        /* It is large page*/
                        if (largepage_lvl > 1) {
                                unsigned long end_pfn;
                                unsigned long pages_to_remove;

                                pteval |= DMA_PTE_LARGE_PAGE;
                                pages_to_remove = min_t(unsigned long, nr_pages,
                                                        nr_pte_to_next_page(pte) * lvl_pages);
                                end_pfn = iov_pfn + pages_to_remove - 1;
                                switch_to_super_page(domain, iov_pfn, end_pfn, largepage_lvl);
                        } else {
                                pteval &= ~(uint64_t)DMA_PTE_LARGE_PAGE;
                        }

                }
                /* We don't need lock here, nobody else
                 * touches the iova range
                 */
                tmp = cmpxchg64_local(&pte->val, 0ULL, pteval);
                if (tmp) {
                        static int dumps = 5;
                        pr_crit("ERROR: DMA PTE for vPFN 0x%lx already set (to %llx not %llx)\n",
                                iov_pfn, tmp, (unsigned long long)pteval);
                        if (dumps) {
                                dumps--;
                                debug_dma_dump_mappings(NULL);
                        }
                        WARN_ON(1);
                }

                nr_pages -= lvl_pages;
                iov_pfn += lvl_pages;
                phys_pfn += lvl_pages;
                pteval += lvl_pages * VTD_PAGE_SIZE;

                /* If the next PTE would be the first in a new page, then we
                 * need to flush the cache on the entries we've just written.
                 * And then we'll need to recalculate 'pte', so clear it and
                 * let it get set again in the if (!pte) block above.
                 *
                 * If we're done (!nr_pages) we need to flush the cache too.
                 *
                 * Also if we've been setting superpages, we may need to
                 * recalculate 'pte' and switch back to smaller pages for the
                 * end of the mapping, if the trailing size is not enough to
                 * use another superpage (i.e. nr_pages < lvl_pages).
                 */
                pte++;
                if (!nr_pages || first_pte_in_page(pte) ||
                    (largepage_lvl > 1 && nr_pages < lvl_pages)) {
                        domain_flush_cache(domain, first_pte,
                                           (void *)pte - (void *)first_pte);
                        pte = NULL;
                }
        }

        return 0;
}

static void domain_context_clear_one(struct device_domain_info *info, u8 bus, u8 devfn)
{
        struct intel_iommu *iommu = info->iommu;
        struct context_entry *context;
        u16 did_old;

        spin_lock(&iommu->lock);
        context = iommu_context_addr(iommu, bus, devfn, 0);
        if (!context) {
                spin_unlock(&iommu->lock);
                return;
        }

        did_old = context_domain_id(context);

        context_clear_entry(context);
        __iommu_flush_cache(iommu, context, sizeof(*context));
        spin_unlock(&iommu->lock);
        iommu->flush.flush_context(iommu,
                                   did_old,
                                   (((u16)bus) << 8) | devfn,
                                   DMA_CCMD_MASK_NOBIT,
                                   DMA_CCMD_DEVICE_INVL);

        iommu->flush.flush_iotlb(iommu,
                                 did_old,
                                 0,
                                 0,
                                 DMA_TLB_DSI_FLUSH);

        __iommu_flush_dev_iotlb(info, 0, MAX_AGAW_PFN_WIDTH);
}

static int domain_setup_first_level(struct intel_iommu *iommu,
                                    struct dmar_domain *domain,
                                    struct device *dev,
                                    u32 pasid)
{
        struct dma_pte *pgd = domain->pgd;
        int agaw, level;
        int flags = 0;

        /*
         * Skip top levels of page tables for iommu which has
         * less agaw than default. Unnecessary for PT mode.
         */
        for (agaw = domain->agaw; agaw > iommu->agaw; agaw--) {
                pgd = phys_to_virt(dma_pte_addr(pgd));
                if (!dma_pte_present(pgd))
                        return -ENOMEM;
        }

        level = agaw_to_level(agaw);
        if (level != 4 && level != 5)
                return -EINVAL;

        if (level == 5)
                flags |= PASID_FLAG_FL5LP;

        if (domain->force_snooping)
                flags |= PASID_FLAG_PAGE_SNOOP;

        return intel_pasid_setup_first_level(iommu, dev, (pgd_t *)pgd, pasid,
                                             domain_id_iommu(domain, iommu),
                                             flags);
}

static bool dev_is_real_dma_subdevice(struct device *dev)
{
        return dev && dev_is_pci(dev) &&
               pci_real_dma_dev(to_pci_dev(dev)) != to_pci_dev(dev);
}

static int iommu_domain_identity_map(struct dmar_domain *domain,
                                     unsigned long first_vpfn,
                                     unsigned long last_vpfn)
{
        /*
         * RMRR range might have overlap with physical memory range,
         * clear it first
         */
        dma_pte_clear_range(domain, first_vpfn, last_vpfn);

        return __domain_mapping(domain, first_vpfn,
                                first_vpfn, last_vpfn - first_vpfn + 1,
                                DMA_PTE_READ|DMA_PTE_WRITE, GFP_KERNEL);
}

static int md_domain_init(struct dmar_domain *domain, int guest_width);

static int __init si_domain_init(int hw)
{
        struct dmar_rmrr_unit *rmrr;
        struct device *dev;
        int i, nid, ret;

        si_domain = alloc_domain(IOMMU_DOMAIN_IDENTITY);
        if (!si_domain)
                return -EFAULT;

        if (md_domain_init(si_domain, DEFAULT_DOMAIN_ADDRESS_WIDTH)) {
                domain_exit(si_domain);
                si_domain = NULL;
                return -EFAULT;
        }

        if (hw)
                return 0;

        for_each_online_node(nid) {
                unsigned long start_pfn, end_pfn;
                int i;

                for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, NULL) {
                        ret = iommu_domain_identity_map(si_domain,
                                        mm_to_dma_pfn_start(start_pfn),
                                        mm_to_dma_pfn_end(end_pfn));
                        if (ret)
                                return ret;
                }
        }

        /*
         * Identity map the RMRRs so that devices with RMRRs could also use
         * the si_domain.
         */
        for_each_rmrr_units(rmrr) {
                for_each_active_dev_scope(rmrr->devices, rmrr->devices_cnt,
                                          i, dev) {
                        unsigned long long start = rmrr->base_address;
                        unsigned long long end = rmrr->end_address;

                        if (WARN_ON(end < start ||
                                    end >> agaw_to_width(si_domain->agaw)))
                                continue;

                        ret = iommu_domain_identity_map(si_domain,
                                        mm_to_dma_pfn_start(start >> PAGE_SHIFT),
                                        mm_to_dma_pfn_end(end >> PAGE_SHIFT));
                        if (ret)
                                return ret;
                }
        }

        return 0;
}

static int dmar_domain_attach_device(struct dmar_domain *domain,
                                     struct device *dev)
{
        struct device_domain_info *info = dev_iommu_priv_get(dev);
        struct intel_iommu *iommu = info->iommu;
        unsigned long flags;
        int ret;

        ret = domain_attach_iommu(domain, iommu);
        if (ret)
                return ret;
        info->domain = domain;
        spin_lock_irqsave(&domain->lock, flags);
        list_add(&info->link, &domain->devices);
        spin_unlock_irqrestore(&domain->lock, flags);

        if (dev_is_real_dma_subdevice(dev))
                return 0;

        if (!sm_supported(iommu))
                ret = domain_context_mapping(domain, dev);
        else if (hw_pass_through && domain_type_is_si(domain))
                ret = intel_pasid_setup_pass_through(iommu, dev, IOMMU_NO_PASID);
        else if (domain->use_first_level)
                ret = domain_setup_first_level(iommu, domain, dev, IOMMU_NO_PASID);
        else
                ret = intel_pasid_setup_second_level(iommu, domain, dev, IOMMU_NO_PASID);

        if (ret) {
                device_block_translation(dev);
                return ret;
        }

        if (sm_supported(info->iommu) || !domain_type_is_si(info->domain))
                iommu_enable_pci_caps(info);

        return 0;
}

/**
 * device_rmrr_is_relaxable - Test whether the RMRR of this device
 * is relaxable (ie. is allowed to be not enforced under some conditions)
 * @dev: device handle
 *
 * We assume that PCI USB devices with RMRRs have them largely
 * for historical reasons and that the RMRR space is not actively used post
 * boot.  This exclusion may change if vendors begin to abuse it.
 *
 * The same exception is made for graphics devices, with the requirement that
 * any use of the RMRR regions will be torn down before assigning the device
 * to a guest.
 *
 * Return: true if the RMRR is relaxable, false otherwise
 */
static bool device_rmrr_is_relaxable(struct device *dev)
{
        struct pci_dev *pdev;

        if (!dev_is_pci(dev))
                return false;

        pdev = to_pci_dev(dev);
        if (IS_USB_DEVICE(pdev) || IS_GFX_DEVICE(pdev))
                return true;
        else
                return false;
}

/*
 * Return the required default domain type for a specific device.
 *
 * @dev: the device in query
 * @startup: true if this is during early boot
 *
 * Returns:
 *  - IOMMU_DOMAIN_DMA: device requires a dynamic mapping domain
 *  - IOMMU_DOMAIN_IDENTITY: device requires an identical mapping domain
 *  - 0: both identity and dynamic domains work for this device
 */
static int device_def_domain_type(struct device *dev)
{
        if (dev_is_pci(dev)) {
                struct pci_dev *pdev = to_pci_dev(dev);

                if ((iommu_identity_mapping & IDENTMAP_AZALIA) && IS_AZALIA(pdev))
                        return IOMMU_DOMAIN_IDENTITY;

                if ((iommu_identity_mapping & IDENTMAP_GFX) && IS_GFX_DEVICE(pdev))
                        return IOMMU_DOMAIN_IDENTITY;
        }

        return 0;
}

static void intel_iommu_init_qi(struct intel_iommu *iommu)
{
        /*
         * Start from the sane iommu hardware state.
         * If the queued invalidation is already initialized by us
         * (for example, while enabling interrupt-remapping) then
         * we got the things already rolling from a sane state.
         */
        if (!iommu->qi) {
                /*
                 * Clear any previous faults.
                 */
                dmar_fault(-1, iommu);
                /*
                 * Disable queued invalidation if supported and already enabled
                 * before OS handover.
                 */
                dmar_disable_qi(iommu);
        }

        if (dmar_enable_qi(iommu)) {
                /*
                 * Queued Invalidate not enabled, use Register Based Invalidate
                 */
                iommu->flush.flush_context = __iommu_flush_context;
                iommu->flush.flush_iotlb = __iommu_flush_iotlb;
                pr_info("%s: Using Register based invalidation\n",
                        iommu->name);
        } else {
                iommu->flush.flush_context = qi_flush_context;
                iommu->flush.flush_iotlb = qi_flush_iotlb;
                pr_info("%s: Using Queued invalidation\n", iommu->name);
        }
}

static int copy_context_table(struct intel_iommu *iommu,
                              struct root_entry *old_re,
                              struct context_entry **tbl,
                              int bus, bool ext)
{
        int tbl_idx, pos = 0, idx, devfn, ret = 0, did;
        struct context_entry *new_ce = NULL, ce;
        struct context_entry *old_ce = NULL;
        struct root_entry re;
        phys_addr_t old_ce_phys;

        tbl_idx = ext ? bus * 2 : bus;
        memcpy(&re, old_re, sizeof(re));

        for (devfn = 0; devfn < 256; devfn++) {
                /* First calculate the correct index */
                idx = (ext ? devfn * 2 : devfn) % 256;

                if (idx == 0) {
                        /* First save what we may have and clean up */
                        if (new_ce) {
                                tbl[tbl_idx] = new_ce;
                                __iommu_flush_cache(iommu, new_ce,
                                                    VTD_PAGE_SIZE);
                                pos = 1;
                        }

                        if (old_ce)
                                memunmap(old_ce);

                        ret = 0;
                        if (devfn < 0x80)
                                old_ce_phys = root_entry_lctp(&re);
                        else
                                old_ce_phys = root_entry_uctp(&re);

                        if (!old_ce_phys) {
                                if (ext && devfn == 0) {
                                        /* No LCTP, try UCTP */
                                        devfn = 0x7f;
                                        continue;
                                } else {
                                        goto out;
                                }
                        }

                        ret = -ENOMEM;
                        old_ce = memremap(old_ce_phys, PAGE_SIZE,
                                        MEMREMAP_WB);
                        if (!old_ce)
                                goto out;

                        new_ce = alloc_pgtable_page(iommu->node, GFP_KERNEL);
                        if (!new_ce)
                                goto out_unmap;

                        ret = 0;
                }

                /* Now copy the context entry */
                memcpy(&ce, old_ce + idx, sizeof(ce));

                if (!context_present(&ce))
                        continue;

                did = context_domain_id(&ce);
                if (did >= 0 && did < cap_ndoms(iommu->cap))
                        set_bit(did, iommu->domain_ids);

                set_context_copied(iommu, bus, devfn);
                new_ce[idx] = ce;
        }

        tbl[tbl_idx + pos] = new_ce;

        __iommu_flush_cache(iommu, new_ce, VTD_PAGE_SIZE);

out_unmap:
        memunmap(old_ce);

out:
        return ret;
}

static int copy_translation_tables(struct intel_iommu *iommu)
{
        struct context_entry **ctxt_tbls;
        struct root_entry *old_rt;
        phys_addr_t old_rt_phys;
        int ctxt_table_entries;
        u64 rtaddr_reg;
        int bus, ret;
        bool new_ext, ext;

        rtaddr_reg = dmar_readq(iommu->reg + DMAR_RTADDR_REG);
        ext        = !!(rtaddr_reg & DMA_RTADDR_SMT);
        new_ext    = !!sm_supported(iommu);

        /*
         * The RTT bit can only be changed when translation is disabled,
         * but disabling translation means to open a window for data
         * corruption. So bail out and don't copy anything if we would
         * have to change the bit.
         */
        if (new_ext != ext)
                return -EINVAL;

        iommu->copied_tables = bitmap_zalloc(BIT_ULL(16), GFP_KERNEL);
        if (!iommu->copied_tables)
                return -ENOMEM;

        old_rt_phys = rtaddr_reg & VTD_PAGE_MASK;
        if (!old_rt_phys)
                return -EINVAL;

        old_rt = memremap(old_rt_phys, PAGE_SIZE, MEMREMAP_WB);
        if (!old_rt)
                return -ENOMEM;

        /* This is too big for the stack - allocate it from slab */
        ctxt_table_entries = ext ? 512 : 256;
        ret = -ENOMEM;
        ctxt_tbls = kcalloc(ctxt_table_entries, sizeof(void *), GFP_KERNEL);
        if (!ctxt_tbls)
                goto out_unmap;

        for (bus = 0; bus < 256; bus++) {
                ret = copy_context_table(iommu, &old_rt[bus],
                                         ctxt_tbls, bus, ext);
                if (ret) {
                        pr_err("%s: Failed to copy context table for bus %d\n",
                                iommu->name, bus);
                        continue;
                }
        }

        spin_lock(&iommu->lock);

        /* Context tables are copied, now write them to the root_entry table */
        for (bus = 0; bus < 256; bus++) {
                int idx = ext ? bus * 2 : bus;
                u64 val;

                if (ctxt_tbls[idx]) {
                        val = virt_to_phys(ctxt_tbls[idx]) | 1;
                        iommu->root_entry[bus].lo = val;
                }

                if (!ext || !ctxt_tbls[idx + 1])
                        continue;

                val = virt_to_phys(ctxt_tbls[idx + 1]) | 1;
                iommu->root_entry[bus].hi = val;
        }

        spin_unlock(&iommu->lock);

        kfree(ctxt_tbls);

        __iommu_flush_cache(iommu, iommu->root_entry, PAGE_SIZE);

        ret = 0;

out_unmap:
        memunmap(old_rt);

        return ret;
}

static int __init init_dmars(void)
{
        struct dmar_drhd_unit *drhd;
        struct intel_iommu *iommu;
        int ret;

        ret = intel_cap_audit(CAP_AUDIT_STATIC_DMAR, NULL);
        if (ret)
                goto free_iommu;

        for_each_iommu(iommu, drhd) {
                if (drhd->ignored) {
                        iommu_disable_translation(iommu);
                        continue;
                }

                /*
                 * Find the max pasid size of all IOMMU's in the system.
                 * We need to ensure the system pasid table is no bigger
                 * than the smallest supported.
                 */
                if (pasid_supported(iommu)) {
                        u32 temp = 2 << ecap_pss(iommu->ecap);

                        intel_pasid_max_id = min_t(u32, temp,
                                                   intel_pasid_max_id);
                }

                intel_iommu_init_qi(iommu);

                ret = iommu_init_domains(iommu);
                if (ret)
                        goto free_iommu;

                init_translation_status(iommu);

                if (translation_pre_enabled(iommu) && !is_kdump_kernel()) {
                        iommu_disable_translation(iommu);
                        clear_translation_pre_enabled(iommu);
                        pr_warn("Translation was enabled for %s but we are not in kdump mode\n",
                                iommu->name);
                }

                /*
                 * TBD:
                 * we could share the same root & context tables
                 * among all IOMMU's. Need to Split it later.
                 */
                ret = iommu_alloc_root_entry(iommu);
                if (ret)
                        goto free_iommu;

                if (translation_pre_enabled(iommu)) {
                        pr_info("Translation already enabled - trying to copy translation structures\n");

                        ret = copy_translation_tables(iommu);
                        if (ret) {
                                /*
                                 * We found the IOMMU with translation
                                 * enabled - but failed to copy over the
                                 * old root-entry table. Try to proceed
                                 * by disabling translation now and
                                 * allocating a clean root-entry table.
                                 * This might cause DMAR faults, but
                                 * probably the dump will still succeed.
                                 */
                                pr_err("Failed to copy translation tables from previous kernel for %s\n",
                                       iommu->name);
                                iommu_disable_translation(iommu);
                                clear_translation_pre_enabled(iommu);
                        } else {
                                pr_info("Copied translation tables from previous kernel for %s\n",
                                        iommu->name);
                        }
                }

                if (!ecap_pass_through(iommu->ecap))
                        hw_pass_through = 0;
                intel_svm_check(iommu);
        }

        /*
         * Now that qi is enabled on all iommus, set the root entry and flush
         * caches. This is required on some Intel X58 chipsets, otherwise the
         * flush_context function will loop forever and the boot hangs.
         */
        for_each_active_iommu(iommu, drhd) {
                iommu_flush_write_buffer(iommu);
                iommu_set_root_entry(iommu);
        }

        if (!dmar_map_gfx)
                iommu_identity_mapping |= IDENTMAP_GFX;

        check_tylersburg_isoch();

        ret = si_domain_init(hw_pass_through);
        if (ret)
                goto free_iommu;

        /*
         * for each drhd
         *   enable fault log
         *   global invalidate context cache
         *   global invalidate iotlb
         *   enable translation
         */
        for_each_iommu(iommu, drhd) {
                if (drhd->ignored) {
                        /*
                         * we always have to disable PMRs or DMA may fail on
                         * this device
                         */
                        if (force_on)
                                iommu_disable_protect_mem_regions(iommu);
                        continue;
                }

                iommu_flush_write_buffer(iommu);

#ifdef CONFIG_INTEL_IOMMU_SVM
                if (pasid_supported(iommu) && ecap_prs(iommu->ecap)) {
                        /*
                         * Call dmar_alloc_hwirq() with dmar_global_lock held,
                         * could cause possible lock race condition.
                         */
                        up_write(&dmar_global_lock);
                        ret = intel_svm_enable_prq(iommu);
                        down_write(&dmar_global_lock);
                        if (ret)
                                goto free_iommu;
                }
#endif
                ret = dmar_set_interrupt(iommu);
                if (ret)
                        goto free_iommu;
        }

        return 0;

free_iommu:
        for_each_active_iommu(iommu, drhd) {
                disable_dmar_iommu(iommu);
                free_dmar_iommu(iommu);
        }
        if (si_domain) {
                domain_exit(si_domain);
                si_domain = NULL;
        }

        return ret;
}

static void __init init_no_remapping_devices(void)
{
        struct dmar_drhd_unit *drhd;
        struct device *dev;
        int i;

        for_each_drhd_unit(drhd) {
                if (!drhd->include_all) {
                        for_each_active_dev_scope(drhd->devices,
                                                  drhd->devices_cnt, i, dev)
                                break;
                        /* ignore DMAR unit if no devices exist */
                        if (i == drhd->devices_cnt)
                                drhd->ignored = 1;
                }
        }

        for_each_active_drhd_unit(drhd) {
                if (drhd->include_all)
                        continue;

                for_each_active_dev_scope(drhd->devices,
                                          drhd->devices_cnt, i, dev)
                        if (!dev_is_pci(dev) || !IS_GFX_DEVICE(to_pci_dev(dev)))
                                break;
                if (i < drhd->devices_cnt)
                        continue;

                /* This IOMMU has *only* gfx devices. Either bypass it or
                   set the gfx_mapped flag, as appropriate */
                drhd->gfx_dedicated = 1;
                if (!dmar_map_gfx)
                        drhd->ignored = 1;
        }
}

#ifdef CONFIG_SUSPEND
static int init_iommu_hw(void)
{
        struct dmar_drhd_unit *drhd;
        struct intel_iommu *iommu = NULL;
        int ret;

        for_each_active_iommu(iommu, drhd) {
                if (iommu->qi) {
                        ret = dmar_reenable_qi(iommu);
                        if (ret)
                                return ret;
                }
        }

        for_each_iommu(iommu, drhd) {
                if (drhd->ignored) {
                        /*
                         * we always have to disable PMRs or DMA may fail on
                         * this device
                         */
                        if (force_on)
                                iommu_disable_protect_mem_regions(iommu);
                        continue;
                }

                iommu_flush_write_buffer(iommu);
                iommu_set_root_entry(iommu);
                iommu_enable_translation(iommu);
                iommu_disable_protect_mem_regions(iommu);
        }

        return 0;
}

static void iommu_flush_all(void)
{
        struct dmar_drhd_unit *drhd;
        struct intel_iommu *iommu;

        for_each_active_iommu(iommu, drhd) {
                iommu->flush.flush_context(iommu, 0, 0, 0,
                                           DMA_CCMD_GLOBAL_INVL);
                iommu->flush.flush_iotlb(iommu, 0, 0, 0,
                                         DMA_TLB_GLOBAL_FLUSH);
        }
}

static int iommu_suspend(void)
{
        struct dmar_drhd_unit *drhd;
        struct intel_iommu *iommu = NULL;
        unsigned long flag;

        iommu_flush_all();

        for_each_active_iommu(iommu, drhd) {
                iommu_disable_translation(iommu);

                raw_spin_lock_irqsave(&iommu->register_lock, flag);

                iommu->iommu_state[SR_DMAR_FECTL_REG] =
                        readl(iommu->reg + DMAR_FECTL_REG);
                iommu->iommu_state[SR_DMAR_FEDATA_REG] =
                        readl(iommu->reg + DMAR_FEDATA_REG);
                iommu->iommu_state[SR_DMAR_FEADDR_REG] =
                        readl(iommu->reg + DMAR_FEADDR_REG);
                iommu->iommu_state[SR_DMAR_FEUADDR_REG] =
                        readl(iommu->reg + DMAR_FEUADDR_REG);

                raw_spin_unlock_irqrestore(&iommu->register_lock, flag);
        }
        return 0;
}

static void iommu_resume(void)
{
        struct dmar_drhd_unit *drhd;
        struct intel_iommu *iommu = NULL;
        unsigned long flag;

        if (init_iommu_hw()) {
                if (force_on)
                        panic("tboot: IOMMU setup failed, DMAR can not resume!\n");
                else
                        WARN(1, "IOMMU setup failed, DMAR can not resume!\n");
                return;
        }

        for_each_active_iommu(iommu, drhd) {

                raw_spin_lock_irqsave(&iommu->register_lock, flag);

                writel(iommu->iommu_state[SR_DMAR_FECTL_REG],
                        iommu->reg + DMAR_FECTL_REG);
                writel(iommu->iommu_state[SR_DMAR_FEDATA_REG],
                        iommu->reg + DMAR_FEDATA_REG);
                writel(iommu->iommu_state[SR_DMAR_FEADDR_REG],
                        iommu->reg + DMAR_FEADDR_REG);
                writel(iommu->iommu_state[SR_DMAR_FEUADDR_REG],
                        iommu->reg + DMAR_FEUADDR_REG);

                raw_spin_unlock_irqrestore(&iommu->register_lock, flag);
        }
}

static struct syscore_ops iommu_syscore_ops = {
        .resume         = iommu_resume,
        .suspend        = iommu_suspend,
};

static void __init init_iommu_pm_ops(void)
{
        register_syscore_ops(&iommu_syscore_ops);
}

#else
static inline void init_iommu_pm_ops(void) {}
#endif  /* CONFIG_PM */

static int __init rmrr_sanity_check(struct acpi_dmar_reserved_memory *rmrr)
{
        if (!IS_ALIGNED(rmrr->base_address, PAGE_SIZE) ||
            !IS_ALIGNED(rmrr->end_address + 1, PAGE_SIZE) ||
            rmrr->end_address <= rmrr->base_address ||
            arch_rmrr_sanity_check(rmrr))
                return -EINVAL;

        return 0;
}

int __init dmar_parse_one_rmrr(struct acpi_dmar_header *header, void *arg)
{
        struct acpi_dmar_reserved_memory *rmrr;
        struct dmar_rmrr_unit *rmrru;

        rmrr = (struct acpi_dmar_reserved_memory *)header;
        if (rmrr_sanity_check(rmrr)) {
                pr_warn(FW_BUG
                           "Your BIOS is broken; bad RMRR [%#018Lx-%#018Lx]\n"
                           "BIOS vendor: %s; Ver: %s; Product Version: %s\n",
                           rmrr->base_address, rmrr->end_address,
                           dmi_get_system_info(DMI_BIOS_VENDOR),
                           dmi_get_system_info(DMI_BIOS_VERSION),
                           dmi_get_system_info(DMI_PRODUCT_VERSION));
                add_taint(TAINT_FIRMWARE_WORKAROUND, LOCKDEP_STILL_OK);
        }

        rmrru = kzalloc(sizeof(*rmrru), GFP_KERNEL);
        if (!rmrru)
                goto out;

        rmrru->hdr = header;

        rmrru->base_address = rmrr->base_address;
        rmrru->end_address = rmrr->end_address;

        rmrru->devices = dmar_alloc_dev_scope((void *)(rmrr + 1),
                                ((void *)rmrr) + rmrr->header.length,
                                &rmrru->devices_cnt);
        if (rmrru->devices_cnt && rmrru->devices == NULL)
                goto free_rmrru;

        list_add(&rmrru->list, &dmar_rmrr_units);

        return 0;
free_rmrru:
        kfree(rmrru);
out:
        return -ENOMEM;
}

static struct dmar_atsr_unit *dmar_find_atsr(struct acpi_dmar_atsr *atsr)
{
        struct dmar_atsr_unit *atsru;
        struct acpi_dmar_atsr *tmp;

        list_for_each_entry_rcu(atsru, &dmar_atsr_units, list,
                                dmar_rcu_check()) {
                tmp = (struct acpi_dmar_atsr *)atsru->hdr;
                if (atsr->segment != tmp->segment)
                        continue;
                if (atsr->header.length != tmp->header.length)
                        continue;
                if (memcmp(atsr, tmp, atsr->header.length) == 0)
                        return atsru;
        }

        return NULL;
}

int dmar_parse_one_atsr(struct acpi_dmar_header *hdr, void *arg)
{
        struct acpi_dmar_atsr *atsr;
        struct dmar_atsr_unit *atsru;

        if (system_state >= SYSTEM_RUNNING && !intel_iommu_enabled)
                return 0;

        atsr = container_of(hdr, struct acpi_dmar_atsr, header);
        atsru = dmar_find_atsr(atsr);
        if (atsru)
                return 0;

        atsru = kzalloc(sizeof(*atsru) + hdr->length, GFP_KERNEL);
        if (!atsru)
                return -ENOMEM;

        /*
         * If memory is allocated from slab by ACPI _DSM method, we need to
         * copy the memory content because the memory buffer will be freed
         * on return.
         */
        atsru->hdr = (void *)(atsru + 1);
        memcpy(atsru->hdr, hdr, hdr->length);
        atsru->include_all = atsr->flags & 0x1;
        if (!atsru->include_all) {
                atsru->devices = dmar_alloc_dev_scope((void *)(atsr + 1),
                                (void *)atsr + atsr->header.length,
                                &atsru->devices_cnt);
                if (atsru->devices_cnt && atsru->devices == NULL) {
                        kfree(atsru);
                        return -ENOMEM;
                }
        }

        list_add_rcu(&atsru->list, &dmar_atsr_units);

        return 0;
}

static void intel_iommu_free_atsr(struct dmar_atsr_unit *atsru)
{
        dmar_free_dev_scope(&atsru->devices, &atsru->devices_cnt);
        kfree(atsru);
}

int dmar_release_one_atsr(struct acpi_dmar_header *hdr, void *arg)
{
        struct acpi_dmar_atsr *atsr;
        struct dmar_atsr_unit *atsru;

        atsr = container_of(hdr, struct acpi_dmar_atsr, header);
        atsru = dmar_find_atsr(atsr);
        if (atsru) {
                list_del_rcu(&atsru->list);
                synchronize_rcu();
                intel_iommu_free_atsr(atsru);
        }

        return 0;
}

int dmar_check_one_atsr(struct acpi_dmar_header *hdr, void *arg)
{
        int i;
        struct device *dev;
        struct acpi_dmar_atsr *atsr;
        struct dmar_atsr_unit *atsru;

        atsr = container_of(hdr, struct acpi_dmar_atsr, header);
        atsru = dmar_find_atsr(atsr);
        if (!atsru)
                return 0;

        if (!atsru->include_all && atsru->devices && atsru->devices_cnt) {
                for_each_active_dev_scope(atsru->devices, atsru->devices_cnt,
                                          i, dev)
                        return -EBUSY;
        }

        return 0;
}

static struct dmar_satc_unit *dmar_find_satc(struct acpi_dmar_satc *satc)
{
        struct dmar_satc_unit *satcu;
        struct acpi_dmar_satc *tmp;

        list_for_each_entry_rcu(satcu, &dmar_satc_units, list,
                                dmar_rcu_check()) {
                tmp = (struct acpi_dmar_satc *)satcu->hdr;
                if (satc->segment != tmp->segment)
                        continue;
                if (satc->header.length != tmp->header.length)
                        continue;
                if (memcmp(satc, tmp, satc->header.length) == 0)
                        return satcu;
        }

        return NULL;
}

int dmar_parse_one_satc(struct acpi_dmar_header *hdr, void *arg)
{
        struct acpi_dmar_satc *satc;
        struct dmar_satc_unit *satcu;

        if (system_state >= SYSTEM_RUNNING && !intel_iommu_enabled)
                return 0;

        satc = container_of(hdr, struct acpi_dmar_satc, header);
        satcu = dmar_find_satc(satc);
        if (satcu)
                return 0;

        satcu = kzalloc(sizeof(*satcu) + hdr->length, GFP_KERNEL);
        if (!satcu)
                return -ENOMEM;

        satcu->hdr = (void *)(satcu + 1);
        memcpy(satcu->hdr, hdr, hdr->length);
        satcu->atc_required = satc->flags & 0x1;
        satcu->devices = dmar_alloc_dev_scope((void *)(satc + 1),
                                              (void *)satc + satc->header.length,
                                              &satcu->devices_cnt);
        if (satcu->devices_cnt && !satcu->devices) {
                kfree(satcu);
                return -ENOMEM;
        }
        list_add_rcu(&satcu->list, &dmar_satc_units);

        return 0;
}

static int intel_iommu_add(struct dmar_drhd_unit *dmaru)
{
        int sp, ret;
        struct intel_iommu *iommu = dmaru->iommu;

        ret = intel_cap_audit(CAP_AUDIT_HOTPLUG_DMAR, iommu);
        if (ret)
                goto out;

        if (hw_pass_through && !ecap_pass_through(iommu->ecap)) {
                pr_warn("%s: Doesn't support hardware pass through.\n",
                        iommu->name);
                return -ENXIO;
        }

        sp = domain_update_iommu_superpage(NULL, iommu) - 1;
        if (sp >= 0 && !(cap_super_page_val(iommu->cap) & (1 << sp))) {
                pr_warn("%s: Doesn't support large page.\n",
                        iommu->name);
                return -ENXIO;
        }

        /*
         * Disable translation if already enabled prior to OS handover.
         */
        if (iommu->gcmd & DMA_GCMD_TE)
                iommu_disable_translation(iommu);

        ret = iommu_init_domains(iommu);
        if (ret == 0)
                ret = iommu_alloc_root_entry(iommu);
        if (ret)
                goto out;

        intel_svm_check(iommu);

        if (dmaru->ignored) {
                /*
                 * we always have to disable PMRs or DMA may fail on this device
                 */
                if (force_on)
                        iommu_disable_protect_mem_regions(iommu);
                return 0;
        }

        intel_iommu_init_qi(iommu);
        iommu_flush_write_buffer(iommu);

#ifdef CONFIG_INTEL_IOMMU_SVM
        if (pasid_supported(iommu) && ecap_prs(iommu->ecap)) {
                ret = intel_svm_enable_prq(iommu);
                if (ret)
                        goto disable_iommu;
        }
#endif
        ret = dmar_set_interrupt(iommu);
        if (ret)
                goto disable_iommu;

        iommu_set_root_entry(iommu);
        iommu_enable_translation(iommu);

        iommu_disable_protect_mem_regions(iommu);
        return 0;

disable_iommu:
        disable_dmar_iommu(iommu);
out:
        free_dmar_iommu(iommu);
        return ret;
}

int dmar_iommu_hotplug(struct dmar_drhd_unit *dmaru, bool insert)
{
        int ret = 0;
        struct intel_iommu *iommu = dmaru->iommu;

        if (!intel_iommu_enabled)
                return 0;
        if (iommu == NULL)
                return -EINVAL;

        if (insert) {
                ret = intel_iommu_add(dmaru);
        } else {
                disable_dmar_iommu(iommu);
                free_dmar_iommu(iommu);
        }

        return ret;
}

static void intel_iommu_free_dmars(void)
{
        struct dmar_rmrr_unit *rmrru, *rmrr_n;
        struct dmar_atsr_unit *atsru, *atsr_n;
        struct dmar_satc_unit *satcu, *satc_n;

        list_for_each_entry_safe(rmrru, rmrr_n, &dmar_rmrr_units, list) {
                list_del(&rmrru->list);
                dmar_free_dev_scope(&rmrru->devices, &rmrru->devices_cnt);
                kfree(rmrru);
        }

        list_for_each_entry_safe(atsru, atsr_n, &dmar_atsr_units, list) {
                list_del(&atsru->list);
                intel_iommu_free_atsr(atsru);
        }
        list_for_each_entry_safe(satcu, satc_n, &dmar_satc_units, list) {
                list_del(&satcu->list);
                dmar_free_dev_scope(&satcu->devices, &satcu->devices_cnt);
                kfree(satcu);
        }
}

static struct dmar_satc_unit *dmar_find_matched_satc_unit(struct pci_dev *dev)
{
        struct dmar_satc_unit *satcu;
        struct acpi_dmar_satc *satc;
        struct device *tmp;
        int i;

        dev = pci_physfn(dev);
        rcu_read_lock();

        list_for_each_entry_rcu(satcu, &dmar_satc_units, list) {
                satc = container_of(satcu->hdr, struct acpi_dmar_satc, header);
                if (satc->segment != pci_domain_nr(dev->bus))
                        continue;
                for_each_dev_scope(satcu->devices, satcu->devices_cnt, i, tmp)
                        if (to_pci_dev(tmp) == dev)
                                goto out;
        }
        satcu = NULL;
out:
        rcu_read_unlock();
        return satcu;
}

static int dmar_ats_supported(struct pci_dev *dev, struct intel_iommu *iommu)
{
        int i, ret = 1;
        struct pci_bus *bus;
        struct pci_dev *bridge = NULL;
        struct device *tmp;
        struct acpi_dmar_atsr *atsr;
        struct dmar_atsr_unit *atsru;
        struct dmar_satc_unit *satcu;

        dev = pci_physfn(dev);
        satcu = dmar_find_matched_satc_unit(dev);
        if (satcu)
                /*
                 * This device supports ATS as it is in SATC table.
                 * When IOMMU is in legacy mode, enabling ATS is done
                 * automatically by HW for the device that requires
                 * ATS, hence OS should not enable this device ATS
                 * to avoid duplicated TLB invalidation.
                 */
                return !(satcu->atc_required && !sm_supported(iommu));

        for (bus = dev->bus; bus; bus = bus->parent) {
                bridge = bus->self;
                /* If it's an integrated device, allow ATS */
                if (!bridge)
                        return 1;
                /* Connected via non-PCIe: no ATS */
                if (!pci_is_pcie(bridge) ||
                    pci_pcie_type(bridge) == PCI_EXP_TYPE_PCI_BRIDGE)
                        return 0;
                /* If we found the root port, look it up in the ATSR */
                if (pci_pcie_type(bridge) == PCI_EXP_TYPE_ROOT_PORT)
                        break;
        }

        rcu_read_lock();
        list_for_each_entry_rcu(atsru, &dmar_atsr_units, list) {
                atsr = container_of(atsru->hdr, struct acpi_dmar_atsr, header);
                if (atsr->segment != pci_domain_nr(dev->bus))
                        continue;

                for_each_dev_scope(atsru->devices, atsru->devices_cnt, i, tmp)
                        if (tmp == &bridge->dev)
                                goto out;

                if (atsru->include_all)
                        goto out;
        }
        ret = 0;
out:
        rcu_read_unlock();

        return ret;
}

int dmar_iommu_notify_scope_dev(struct dmar_pci_notify_info *info)
{
        int ret;
        struct dmar_rmrr_unit *rmrru;
        struct dmar_atsr_unit *atsru;
        struct dmar_satc_unit *satcu;
        struct acpi_dmar_atsr *atsr;
        struct acpi_dmar_reserved_memory *rmrr;
        struct acpi_dmar_satc *satc;

        if (!intel_iommu_enabled && system_state >= SYSTEM_RUNNING)
                return 0;

        list_for_each_entry(rmrru, &dmar_rmrr_units, list) {
                rmrr = container_of(rmrru->hdr,
                                    struct acpi_dmar_reserved_memory, header);
                if (info->event == BUS_NOTIFY_ADD_DEVICE) {
                        ret = dmar_insert_dev_scope(info, (void *)(rmrr + 1),
                                ((void *)rmrr) + rmrr->header.length,
                                rmrr->segment, rmrru->devices,
                                rmrru->devices_cnt);
                        if (ret < 0)
                                return ret;
                } else if (info->event == BUS_NOTIFY_REMOVED_DEVICE) {
                        dmar_remove_dev_scope(info, rmrr->segment,
                                rmrru->devices, rmrru->devices_cnt);
                }
        }

        list_for_each_entry(atsru, &dmar_atsr_units, list) {
                if (atsru->include_all)
                        continue;

                atsr = container_of(atsru->hdr, struct acpi_dmar_atsr, header);
                if (info->event == BUS_NOTIFY_ADD_DEVICE) {
                        ret = dmar_insert_dev_scope(info, (void *)(atsr + 1),
                                        (void *)atsr + atsr->header.length,
                                        atsr->segment, atsru->devices,
                                        atsru->devices_cnt);
                        if (ret > 0)
                                break;
                        else if (ret < 0)
                                return ret;
                } else if (info->event == BUS_NOTIFY_REMOVED_DEVICE) {
                        if (dmar_remove_dev_scope(info, atsr->segment,
                                        atsru->devices, atsru->devices_cnt))
                                break;
                }
        }
        list_for_each_entry(satcu, &dmar_satc_units, list) {
                satc = container_of(satcu->hdr, struct acpi_dmar_satc, header);
                if (info->event == BUS_NOTIFY_ADD_DEVICE) {
                        ret = dmar_insert_dev_scope(info, (void *)(satc + 1),
                                        (void *)satc + satc->header.length,
                                        satc->segment, satcu->devices,
                                        satcu->devices_cnt);
                        if (ret > 0)
                                break;
                        else if (ret < 0)
                                return ret;
                } else if (info->event == BUS_NOTIFY_REMOVED_DEVICE) {
                        if (dmar_remove_dev_scope(info, satc->segment,
                                        satcu->devices, satcu->devices_cnt))
                                break;
                }
        }

        return 0;
}

static int intel_iommu_memory_notifier(struct notifier_block *nb,
                                       unsigned long val, void *v)
{
        struct memory_notify *mhp = v;
        unsigned long start_vpfn = mm_to_dma_pfn_start(mhp->start_pfn);
        unsigned long last_vpfn = mm_to_dma_pfn_end(mhp->start_pfn +
                        mhp->nr_pages - 1);

        switch (val) {
        case MEM_GOING_ONLINE:
                if (iommu_domain_identity_map(si_domain,
                                              start_vpfn, last_vpfn)) {
                        pr_warn("Failed to build identity map for [%lx-%lx]\n",
                                start_vpfn, last_vpfn);
                        return NOTIFY_BAD;
                }
                break;

        case MEM_OFFLINE:
        case MEM_CANCEL_ONLINE:
                {
                        struct dmar_drhd_unit *drhd;
                        struct intel_iommu *iommu;
                        LIST_HEAD(freelist);

                        domain_unmap(si_domain, start_vpfn, last_vpfn, &freelist);

                        rcu_read_lock();
                        for_each_active_iommu(iommu, drhd)
                                iommu_flush_iotlb_psi(iommu, si_domain,
                                        start_vpfn, mhp->nr_pages,
                                        list_empty(&freelist), 0);
                        rcu_read_unlock();
                        put_pages_list(&freelist);
                }
                break;
        }

        return NOTIFY_OK;
}

static struct notifier_block intel_iommu_memory_nb = {
        .notifier_call = intel_iommu_memory_notifier,
        .priority = 0
};

static void intel_disable_iommus(void)
{
        struct intel_iommu *iommu = NULL;
        struct dmar_drhd_unit *drhd;

        for_each_iommu(iommu, drhd)
                iommu_disable_translation(iommu);
}

void intel_iommu_shutdown(void)
{
        struct dmar_drhd_unit *drhd;
        struct intel_iommu *iommu = NULL;

        if (no_iommu || dmar_disabled)
                return;

        down_write(&dmar_global_lock);

        /* Disable PMRs explicitly here. */
        for_each_iommu(iommu, drhd)
                iommu_disable_protect_mem_regions(iommu);

        /* Make sure the IOMMUs are switched off */
        intel_disable_iommus();

        up_write(&dmar_global_lock);
}

static struct intel_iommu *dev_to_intel_iommu(struct device *dev)
{
        struct iommu_device *iommu_dev = dev_to_iommu_device(dev);

        return container_of(iommu_dev, struct intel_iommu, iommu);
}

static ssize_t version_show(struct device *dev,
                            struct device_attribute *attr, char *buf)
{
        struct intel_iommu *iommu = dev_to_intel_iommu(dev);
        u32 ver = readl(iommu->reg + DMAR_VER_REG);
        return sysfs_emit(buf, "%d:%d\n",
                          DMAR_VER_MAJOR(ver), DMAR_VER_MINOR(ver));
}
static DEVICE_ATTR_RO(version);

static ssize_t address_show(struct device *dev,
                            struct device_attribute *attr, char *buf)
{
        struct intel_iommu *iommu = dev_to_intel_iommu(dev);
        return sysfs_emit(buf, "%llx\n", iommu->reg_phys);
}
static DEVICE_ATTR_RO(address);

static ssize_t cap_show(struct device *dev,
                        struct device_attribute *attr, char *buf)
{
        struct intel_iommu *iommu = dev_to_intel_iommu(dev);
        return sysfs_emit(buf, "%llx\n", iommu->cap);
}
static DEVICE_ATTR_RO(cap);

static ssize_t ecap_show(struct device *dev,
                         struct device_attribute *attr, char *buf)
{
        struct intel_iommu *iommu = dev_to_intel_iommu(dev);
        return sysfs_emit(buf, "%llx\n", iommu->ecap);
}
static DEVICE_ATTR_RO(ecap);

static ssize_t domains_supported_show(struct device *dev,
                                      struct device_attribute *attr, char *buf)
{
        struct intel_iommu *iommu = dev_to_intel_iommu(dev);
        return sysfs_emit(buf, "%ld\n", cap_ndoms(iommu->cap));
}
static DEVICE_ATTR_RO(domains_supported);

static ssize_t domains_used_show(struct device *dev,
                                 struct device_attribute *attr, char *buf)
{
        struct intel_iommu *iommu = dev_to_intel_iommu(dev);
        return sysfs_emit(buf, "%d\n",
                          bitmap_weight(iommu->domain_ids,
                                        cap_ndoms(iommu->cap)));
}
static DEVICE_ATTR_RO(domains_used);

static struct attribute *intel_iommu_attrs[] = {
        &dev_attr_version.attr,
        &dev_attr_address.attr,
        &dev_attr_cap.attr,
        &dev_attr_ecap.attr,
        &dev_attr_domains_supported.attr,
        &dev_attr_domains_used.attr,
        NULL,
};

static struct attribute_group intel_iommu_group = {
        .name = "intel-iommu",
        .attrs = intel_iommu_attrs,
};

const struct attribute_group *intel_iommu_groups[] = {
        &intel_iommu_group,
        NULL,
};

static bool has_external_pci(void)
{
        struct pci_dev *pdev = NULL;

        for_each_pci_dev(pdev)
                if (pdev->external_facing) {
                        pci_dev_put(pdev);
                        return true;
                }

        return false;
}

static int __init platform_optin_force_iommu(void)
{
        if (!dmar_platform_optin() || no_platform_optin || !has_external_pci())
                return 0;

        if (no_iommu || dmar_disabled)
                pr_info("Intel-IOMMU force enabled due to platform opt in\n");

        /*
         * If Intel-IOMMU is disabled by default, we will apply identity
         * map for all devices except those marked as being untrusted.
         */
        if (dmar_disabled)
                iommu_set_default_passthrough(false);

        dmar_disabled = 0;
        no_iommu = 0;

        return 1;
}

static int __init probe_acpi_namespace_devices(void)
{
        struct dmar_drhd_unit *drhd;
        /* To avoid a -Wunused-but-set-variable warning. */
        struct intel_iommu *iommu __maybe_unused;
        struct device *dev;
        int i, ret = 0;

        for_each_active_iommu(iommu, drhd) {
                for_each_active_dev_scope(drhd->devices,
                                          drhd->devices_cnt, i, dev) {
                        struct acpi_device_physical_node *pn;
                        struct acpi_device *adev;

                        if (dev->bus != &acpi_bus_type)
                                continue;

                        adev = to_acpi_device(dev);
                        mutex_lock(&adev->physical_node_lock);
                        list_for_each_entry(pn,
                                            &adev->physical_node_list, node) {
                                ret = iommu_probe_device(pn->dev);
                                if (ret)
                                        break;
                        }
                        mutex_unlock(&adev->physical_node_lock);

                        if (ret)
                                return ret;
                }
        }

        return 0;
}

static __init int tboot_force_iommu(void)
{
        if (!tboot_enabled())
                return 0;

        if (no_iommu || dmar_disabled)
                pr_warn("Forcing Intel-IOMMU to enabled\n");

        dmar_disabled = 0;
        no_iommu = 0;

        return 1;
}

int __init intel_iommu_init(void)
{
        int ret = -ENODEV;
        struct dmar_drhd_unit *drhd;
        struct intel_iommu *iommu;

        /*
         * Intel IOMMU is required for a TXT/tboot launch or platform
         * opt in, so enforce that.
         */
        force_on = (!intel_iommu_tboot_noforce && tboot_force_iommu()) ||
                    platform_optin_force_iommu();

        down_write(&dmar_global_lock);
        if (dmar_table_init()) {
                if (force_on)
                        panic("tboot: Failed to initialize DMAR table\n");
                goto out_free_dmar;
        }

        if (dmar_dev_scope_init() < 0) {
                if (force_on)
                        panic("tboot: Failed to initialize DMAR device scope\n");
                goto out_free_dmar;
        }

        up_write(&dmar_global_lock);

        /*
         * The bus notifier takes the dmar_global_lock, so lockdep will
         * complain later when we register it under the lock.
         */
        dmar_register_bus_notifier();

        down_write(&dmar_global_lock);

        if (!no_iommu)
                intel_iommu_debugfs_init();

        if (no_iommu || dmar_disabled) {
                /*
                 * We exit the function here to ensure IOMMU's remapping and
                 * mempool aren't setup, which means that the IOMMU's PMRs
                 * won't be disabled via the call to init_dmars(). So disable
                 * it explicitly here. The PMRs were setup by tboot prior to
                 * calling SENTER, but the kernel is expected to reset/tear
                 * down the PMRs.
                 */
                if (intel_iommu_tboot_noforce) {
                        for_each_iommu(iommu, drhd)
                                iommu_disable_protect_mem_regions(iommu);
                }

                /*
                 * Make sure the IOMMUs are switched off, even when we
                 * boot into a kexec kernel and the previous kernel left
                 * them enabled
                 */
                intel_disable_iommus();
                goto out_free_dmar;
        }

        if (list_empty(&dmar_rmrr_units))
                pr_info("No RMRR found\n");

        if (list_empty(&dmar_atsr_units))
                pr_info("No ATSR found\n");

        if (list_empty(&dmar_satc_units))
                pr_info("No SATC found\n");

        init_no_remapping_devices();

        ret = init_dmars();
        if (ret) {
                if (force_on)
                        panic("tboot: Failed to initialize DMARs\n");
                pr_err("Initialization failed\n");
                goto out_free_dmar;
        }
        up_write(&dmar_global_lock);

        init_iommu_pm_ops();

        down_read(&dmar_global_lock);
        for_each_active_iommu(iommu, drhd) {
                /*
                 * The flush queue implementation does not perform
                 * page-selective invalidations that are required for efficient
                 * TLB flushes in virtual environments.  The benefit of batching
                 * is likely to be much lower than the overhead of synchronizing
                 * the virtual and physical IOMMU page-tables.
                 */
                if (cap_caching_mode(iommu->cap) &&
                    !first_level_by_default(IOMMU_DOMAIN_DMA)) {
                        pr_info_once("IOMMU batching disallowed due to virtualization\n");
                        iommu_set_dma_strict();
                }
                iommu_device_sysfs_add(&iommu->iommu, NULL,
                                       intel_iommu_groups,
                                       "%s", iommu->name);
                iommu_device_register(&iommu->iommu, &intel_iommu_ops, NULL);

                iommu_pmu_register(iommu);
        }
        up_read(&dmar_global_lock);

        if (si_domain && !hw_pass_through)
                register_memory_notifier(&intel_iommu_memory_nb);

        down_read(&dmar_global_lock);
        if (probe_acpi_namespace_devices())
                pr_warn("ACPI name space devices didn't probe correctly\n");

        /* Finally, we enable the DMA remapping hardware. */
        for_each_iommu(iommu, drhd) {
                if (!drhd->ignored && !translation_pre_enabled(iommu))
                        iommu_enable_translation(iommu);

                iommu_disable_protect_mem_regions(iommu);
        }
        up_read(&dmar_global_lock);

        pr_info("Intel(R) Virtualization Technology for Directed I/O\n");

        intel_iommu_enabled = 1;

        return 0;

out_free_dmar:
        intel_iommu_free_dmars();
        up_write(&dmar_global_lock);
        return ret;
}

static int domain_context_clear_one_cb(struct pci_dev *pdev, u16 alias, void *opaque)
{
        struct device_domain_info *info = opaque;

        domain_context_clear_one(info, PCI_BUS_NUM(alias), alias & 0xff);
        return 0;
}

/*
 * NB - intel-iommu lacks any sort of reference counting for the users of
 * dependent devices.  If multiple endpoints have intersecting dependent
 * devices, unbinding the driver from any one of them will possibly leave
 * the others unable to operate.
 */
static void domain_context_clear(struct device_domain_info *info)
{
        if (!dev_is_pci(info->dev))
                domain_context_clear_one(info, info->bus, info->devfn);

        pci_for_each_dma_alias(to_pci_dev(info->dev),
                               &domain_context_clear_one_cb, info);
}

/*
 * Clear the page table pointer in context or pasid table entries so that
 * all DMA requests without PASID from the device are blocked. If the page
 * table has been set, clean up the data structures.
 */
void device_block_translation(struct device *dev)
{
        struct device_domain_info *info = dev_iommu_priv_get(dev);
        struct intel_iommu *iommu = info->iommu;
        unsigned long flags;

        iommu_disable_pci_caps(info);
        if (!dev_is_real_dma_subdevice(dev)) {
                if (sm_supported(iommu))
                        intel_pasid_tear_down_entry(iommu, dev,
                                                    IOMMU_NO_PASID, false);
                else
                        domain_context_clear(info);
        }

        if (!info->domain)
                return;

        spin_lock_irqsave(&info->domain->lock, flags);
        list_del(&info->link);
        spin_unlock_irqrestore(&info->domain->lock, flags);

        domain_detach_iommu(info->domain, iommu);
        info->domain = NULL;
}

static int md_domain_init(struct dmar_domain *domain, int guest_width)
{
        int adjust_width;

        /* calculate AGAW */
        domain->gaw = guest_width;
        adjust_width = guestwidth_to_adjustwidth(guest_width);
        domain->agaw = width_to_agaw(adjust_width);

        domain->iommu_coherency = false;
        domain->iommu_superpage = 0;
        domain->max_addr = 0;

        /* always allocate the top pgd */
        domain->pgd = alloc_pgtable_page(domain->nid, GFP_ATOMIC);
        if (!domain->pgd)
                return -ENOMEM;
        domain_flush_cache(domain, domain->pgd, PAGE_SIZE);
        return 0;
}

static int blocking_domain_attach_dev(struct iommu_domain *domain,
                                      struct device *dev)
{
        device_block_translation(dev);
        return 0;
}

static struct iommu_domain blocking_domain = {
        .type = IOMMU_DOMAIN_BLOCKED,
        .ops = &(const struct iommu_domain_ops) {
                .attach_dev     = blocking_domain_attach_dev,
        }
};

static struct iommu_domain *intel_iommu_domain_alloc(unsigned type)
{
        struct dmar_domain *dmar_domain;
        struct iommu_domain *domain;

        switch (type) {
        case IOMMU_DOMAIN_DMA:
        case IOMMU_DOMAIN_UNMANAGED:
                dmar_domain = alloc_domain(type);
                if (!dmar_domain) {
                        pr_err("Can't allocate dmar_domain\n");
                        return NULL;
                }
                if (md_domain_init(dmar_domain, DEFAULT_DOMAIN_ADDRESS_WIDTH)) {
                        pr_err("Domain initialization failed\n");
                        domain_exit(dmar_domain);
                        return NULL;
                }

                domain = &dmar_domain->domain;
                domain->geometry.aperture_start = 0;
                domain->geometry.aperture_end   =
                                __DOMAIN_MAX_ADDR(dmar_domain->gaw);
                domain->geometry.force_aperture = true;

                return domain;
        case IOMMU_DOMAIN_IDENTITY:
                return &si_domain->domain;
        case IOMMU_DOMAIN_SVA:
                return intel_svm_domain_alloc();
        default:
                return NULL;
        }

        return NULL;
}

static struct iommu_domain *
intel_iommu_domain_alloc_user(struct device *dev, u32 flags,
                              struct iommu_domain *parent,
                              const struct iommu_user_data *user_data)
{
        struct device_domain_info *info = dev_iommu_priv_get(dev);
        bool dirty_tracking = flags & IOMMU_HWPT_ALLOC_DIRTY_TRACKING;
        bool nested_parent = flags & IOMMU_HWPT_ALLOC_NEST_PARENT;
        struct intel_iommu *iommu = info->iommu;
        struct dmar_domain *dmar_domain;
        struct iommu_domain *domain;

        /* Must be NESTING domain */
        if (parent) {
                if (!nested_supported(iommu) || flags)
                        return ERR_PTR(-EOPNOTSUPP);
                return intel_nested_domain_alloc(parent, user_data);
        }

        if (flags &
            (~(IOMMU_HWPT_ALLOC_NEST_PARENT | IOMMU_HWPT_ALLOC_DIRTY_TRACKING)))
                return ERR_PTR(-EOPNOTSUPP);
        if (nested_parent && !nested_supported(iommu))
                return ERR_PTR(-EOPNOTSUPP);
        if (user_data || (dirty_tracking && !ssads_supported(iommu)))
                return ERR_PTR(-EOPNOTSUPP);

        /*
         * domain_alloc_user op needs to fully initialize a domain before
         * return, so uses iommu_domain_alloc() here for simple.
         */
        domain = iommu_domain_alloc(dev->bus);
        if (!domain)
                return ERR_PTR(-ENOMEM);

        dmar_domain = to_dmar_domain(domain);

        if (nested_parent) {
                dmar_domain->nested_parent = true;
                INIT_LIST_HEAD(&dmar_domain->s1_domains);
                spin_lock_init(&dmar_domain->s1_lock);
        }

        if (dirty_tracking) {
                if (dmar_domain->use_first_level) {
                        iommu_domain_free(domain);
                        return ERR_PTR(-EOPNOTSUPP);
                }
                domain->dirty_ops = &intel_dirty_ops;
        }

        return domain;
}

static void intel_iommu_domain_free(struct iommu_domain *domain)
{
        struct dmar_domain *dmar_domain = to_dmar_domain(domain);

        WARN_ON(dmar_domain->nested_parent &&
                !list_empty(&dmar_domain->s1_domains));
        if (domain != &si_domain->domain)
                domain_exit(dmar_domain);
}

int prepare_domain_attach_device(struct iommu_domain *domain,
                                 struct device *dev)
{
        struct device_domain_info *info = dev_iommu_priv_get(dev);
        struct dmar_domain *dmar_domain = to_dmar_domain(domain);
        struct intel_iommu *iommu = info->iommu;
        int addr_width;

        if (dmar_domain->force_snooping && !ecap_sc_support(iommu->ecap))
                return -EINVAL;

        if (domain->dirty_ops && !ssads_supported(iommu))
                return -EINVAL;

        /* check if this iommu agaw is sufficient for max mapped address */
        addr_width = agaw_to_width(iommu->agaw);
        if (addr_width > cap_mgaw(iommu->cap))
                addr_width = cap_mgaw(iommu->cap);

        if (dmar_domain->max_addr > (1LL << addr_width))
                return -EINVAL;
        dmar_domain->gaw = addr_width;

        /*
         * Knock out extra levels of page tables if necessary
         */
        while (iommu->agaw < dmar_domain->agaw) {
                struct dma_pte *pte;

                pte = dmar_domain->pgd;
                if (dma_pte_present(pte)) {
                        dmar_domain->pgd = phys_to_virt(dma_pte_addr(pte));
                        free_pgtable_page(pte);
                }
                dmar_domain->agaw--;
        }

        if (sm_supported(iommu) && !dev_is_real_dma_subdevice(dev) &&
            context_copied(iommu, info->bus, info->devfn))
                return intel_pasid_setup_sm_context(dev);

        return 0;
}

static int intel_iommu_attach_device(struct iommu_domain *domain,
                                     struct device *dev)
{
        struct device_domain_info *info = dev_iommu_priv_get(dev);
        int ret;

        if (info->domain)
                device_block_translation(dev);

        ret = prepare_domain_attach_device(domain, dev);
        if (ret)
                return ret;

        return dmar_domain_attach_device(to_dmar_domain(domain), dev);
}

static int intel_iommu_map(struct iommu_domain *domain,
                           unsigned long iova, phys_addr_t hpa,
                           size_t size, int iommu_prot, gfp_t gfp)
{
        struct dmar_domain *dmar_domain = to_dmar_domain(domain);
        u64 max_addr;
        int prot = 0;

        if (iommu_prot & IOMMU_READ)
                prot |= DMA_PTE_READ;
        if (iommu_prot & IOMMU_WRITE)
                prot |= DMA_PTE_WRITE;
        if (dmar_domain->set_pte_snp)
                prot |= DMA_PTE_SNP;

        max_addr = iova + size;
        if (dmar_domain->max_addr < max_addr) {
                u64 end;

                /* check if minimum agaw is sufficient for mapped address */
                end = __DOMAIN_MAX_ADDR(dmar_domain->gaw) + 1;
                if (end < max_addr) {
                        pr_err("%s: iommu width (%d) is not "
                               "sufficient for the mapped address (%llx)\n",
                               __func__, dmar_domain->gaw, max_addr);
                        return -EFAULT;
                }
                dmar_domain->max_addr = max_addr;
        }
        /* Round up size to next multiple of PAGE_SIZE, if it and
           the low bits of hpa would take us onto the next page */
        size = aligned_nrpages(hpa, size);
        return __domain_mapping(dmar_domain, iova >> VTD_PAGE_SHIFT,
                                hpa >> VTD_PAGE_SHIFT, size, prot, gfp);
}

static int intel_iommu_map_pages(struct iommu_domain *domain,
                                 unsigned long iova, phys_addr_t paddr,
                                 size_t pgsize, size_t pgcount,
                                 int prot, gfp_t gfp, size_t *mapped)
{
        unsigned long pgshift = __ffs(pgsize);
        size_t size = pgcount << pgshift;
        int ret;

        if (pgsize != SZ_4K && pgsize != SZ_2M && pgsize != SZ_1G)
                return -EINVAL;

        if (!IS_ALIGNED(iova | paddr, pgsize))
                return -EINVAL;

        ret = intel_iommu_map(domain, iova, paddr, size, prot, gfp);
        if (!ret && mapped)
                *mapped = size;

        return ret;
}

static size_t intel_iommu_unmap(struct iommu_domain *domain,
                                unsigned long iova, size_t size,
                                struct iommu_iotlb_gather *gather)
{
        struct dmar_domain *dmar_domain = to_dmar_domain(domain);
        unsigned long start_pfn, last_pfn;
        int level = 0;

        /* Cope with horrid API which requires us to unmap more than the
           size argument if it happens to be a large-page mapping. */
        if (unlikely(!pfn_to_dma_pte(dmar_domain, iova >> VTD_PAGE_SHIFT,
                                     &level, GFP_ATOMIC)))
                return 0;

        if (size < VTD_PAGE_SIZE << level_to_offset_bits(level))
                size = VTD_PAGE_SIZE << level_to_offset_bits(level);

        start_pfn = iova >> VTD_PAGE_SHIFT;
        last_pfn = (iova + size - 1) >> VTD_PAGE_SHIFT;

        domain_unmap(dmar_domain, start_pfn, last_pfn, &gather->freelist);

        if (dmar_domain->max_addr == iova + size)
                dmar_domain->max_addr = iova;

        /*
         * We do not use page-selective IOTLB invalidation in flush queue,
         * so there is no need to track page and sync iotlb.
         */
        if (!iommu_iotlb_gather_queued(gather))
                iommu_iotlb_gather_add_page(domain, gather, iova, size);

        return size;
}

static size_t intel_iommu_unmap_pages(struct iommu_domain *domain,
                                      unsigned long iova,
                                      size_t pgsize, size_t pgcount,
                                      struct iommu_iotlb_gather *gather)
{
        unsigned long pgshift = __ffs(pgsize);
        size_t size = pgcount << pgshift;

        return intel_iommu_unmap(domain, iova, size, gather);
}

static void intel_iommu_tlb_sync(struct iommu_domain *domain,
                                 struct iommu_iotlb_gather *gather)
{
        struct dmar_domain *dmar_domain = to_dmar_domain(domain);
        unsigned long iova_pfn = IOVA_PFN(gather->start);
        size_t size = gather->end - gather->start;
        struct iommu_domain_info *info;
        unsigned long start_pfn;
        unsigned long nrpages;
        unsigned long i;

        nrpages = aligned_nrpages(gather->start, size);
        start_pfn = mm_to_dma_pfn_start(iova_pfn);

        xa_for_each(&dmar_domain->iommu_array, i, info)
                iommu_flush_iotlb_psi(info->iommu, dmar_domain,
                                      start_pfn, nrpages,
                                      list_empty(&gather->freelist), 0);

        if (dmar_domain->nested_parent)
                parent_domain_flush(dmar_domain, start_pfn, nrpages,
                                    list_empty(&gather->freelist));
        put_pages_list(&gather->freelist);
}

static phys_addr_t intel_iommu_iova_to_phys(struct iommu_domain *domain,
                                            dma_addr_t iova)
{
        struct dmar_domain *dmar_domain = to_dmar_domain(domain);
        struct dma_pte *pte;
        int level = 0;
        u64 phys = 0;

        pte = pfn_to_dma_pte(dmar_domain, iova >> VTD_PAGE_SHIFT, &level,
                             GFP_ATOMIC);
        if (pte && dma_pte_present(pte))
                phys = dma_pte_addr(pte) +
                        (iova & (BIT_MASK(level_to_offset_bits(level) +
                                                VTD_PAGE_SHIFT) - 1));

        return phys;
}

static bool domain_support_force_snooping(struct dmar_domain *domain)
{
        struct device_domain_info *info;
        bool support = true;

        assert_spin_locked(&domain->lock);
        list_for_each_entry(info, &domain->devices, link) {
                if (!ecap_sc_support(info->iommu->ecap)) {
                        support = false;
                        break;
                }
        }

        return support;
}

static void domain_set_force_snooping(struct dmar_domain *domain)
{
        struct device_domain_info *info;

        assert_spin_locked(&domain->lock);
        /*
         * Second level page table supports per-PTE snoop control. The
         * iommu_map() interface will handle this by setting SNP bit.
         */
        if (!domain->use_first_level) {
                domain->set_pte_snp = true;
                return;
        }

        list_for_each_entry(info, &domain->devices, link)
                intel_pasid_setup_page_snoop_control(info->iommu, info->dev,
                                                     IOMMU_NO_PASID);
}

static bool intel_iommu_enforce_cache_coherency(struct iommu_domain *domain)
{
        struct dmar_domain *dmar_domain = to_dmar_domain(domain);
        unsigned long flags;

        if (dmar_domain->force_snooping)
                return true;

        spin_lock_irqsave(&dmar_domain->lock, flags);
        if (!domain_support_force_snooping(dmar_domain) ||
            (!dmar_domain->use_first_level && dmar_domain->has_mappings)) {
                spin_unlock_irqrestore(&dmar_domain->lock, flags);
                return false;
        }

        domain_set_force_snooping(dmar_domain);
        dmar_domain->force_snooping = true;
        spin_unlock_irqrestore(&dmar_domain->lock, flags);

        return true;
}

static bool intel_iommu_capable(struct device *dev, enum iommu_cap cap)
{
        struct device_domain_info *info = dev_iommu_priv_get(dev);

        switch (cap) {
        case IOMMU_CAP_CACHE_COHERENCY:
        case IOMMU_CAP_DEFERRED_FLUSH:
                return true;
        case IOMMU_CAP_PRE_BOOT_PROTECTION:
                return dmar_platform_optin();
        case IOMMU_CAP_ENFORCE_CACHE_COHERENCY:
                return ecap_sc_support(info->iommu->ecap);
        case IOMMU_CAP_DIRTY_TRACKING:
                return ssads_supported(info->iommu);
        default:
                return false;
        }
}

static struct iommu_device *intel_iommu_probe_device(struct device *dev)
{
        struct pci_dev *pdev = dev_is_pci(dev) ? to_pci_dev(dev) : NULL;
        struct device_domain_info *info;
        struct intel_iommu *iommu;
        u8 bus, devfn;
        int ret;

        iommu = device_lookup_iommu(dev, &bus, &devfn);
        if (!iommu || !iommu->iommu.ops)
                return ERR_PTR(-ENODEV);

        info = kzalloc(sizeof(*info), GFP_KERNEL);
        if (!info)
                return ERR_PTR(-ENOMEM);

        if (dev_is_real_dma_subdevice(dev)) {
                info->bus = pdev->bus->number;
                info->devfn = pdev->devfn;
                info->segment = pci_domain_nr(pdev->bus);
        } else {
                info->bus = bus;
                info->devfn = devfn;
                info->segment = iommu->segment;
        }

        info->dev = dev;
        info->iommu = iommu;
        if (dev_is_pci(dev)) {
                if (ecap_dev_iotlb_support(iommu->ecap) &&
                    pci_ats_supported(pdev) &&
                    dmar_ats_supported(pdev, iommu)) {
                        info->ats_supported = 1;
                        info->dtlb_extra_inval = dev_needs_extra_dtlb_flush(pdev);

                        /*
                         * For IOMMU that supports device IOTLB throttling
                         * (DIT), we assign PFSID to the invalidation desc
                         * of a VF such that IOMMU HW can gauge queue depth
                         * at PF level. If DIT is not set, PFSID will be
                         * treated as reserved, which should be set to 0.
                         */
                        if (ecap_dit(iommu->ecap))
                                info->pfsid = pci_dev_id(pci_physfn(pdev));
                        info->ats_qdep = pci_ats_queue_depth(pdev);
                }
                if (sm_supported(iommu)) {
                        if (pasid_supported(iommu)) {
                                int features = pci_pasid_features(pdev);

                                if (features >= 0)
                                        info->pasid_supported = features | 1;
                        }

                        if (info->ats_supported && ecap_prs(iommu->ecap) &&
                            pci_pri_supported(pdev))
                                info->pri_supported = 1;
                }
        }

        dev_iommu_priv_set(dev, info);
        if (pdev && pci_ats_supported(pdev)) {
                ret = device_rbtree_insert(iommu, info);
                if (ret)
                        goto free;
        }

        if (sm_supported(iommu) && !dev_is_real_dma_subdevice(dev)) {
                ret = intel_pasid_alloc_table(dev);
                if (ret) {
                        dev_err(dev, "PASID table allocation failed\n");
                        goto clear_rbtree;
                }

                if (!context_copied(iommu, info->bus, info->devfn)) {
                        ret = intel_pasid_setup_sm_context(dev);
                        if (ret)
                                goto free_table;
                }
        }

        intel_iommu_debugfs_create_dev(info);

        return &iommu->iommu;
free_table:
        intel_pasid_free_table(dev);
clear_rbtree:
        device_rbtree_remove(info);
free:
        kfree(info);

        return ERR_PTR(ret);
}

static void intel_iommu_release_device(struct device *dev)
{
        struct device_domain_info *info = dev_iommu_priv_get(dev);
        struct intel_iommu *iommu = info->iommu;

        mutex_lock(&iommu->iopf_lock);
        if (dev_is_pci(dev) && pci_ats_supported(to_pci_dev(dev)))
                device_rbtree_remove(info);
        mutex_unlock(&iommu->iopf_lock);

        if (sm_supported(iommu) && !dev_is_real_dma_subdevice(dev) &&
            !context_copied(iommu, info->bus, info->devfn))
                intel_pasid_teardown_sm_context(dev);

        intel_pasid_free_table(dev);
        intel_iommu_debugfs_remove_dev(info);
        kfree(info);
        set_dma_ops(dev, NULL);
}

static void intel_iommu_probe_finalize(struct device *dev)
{
        set_dma_ops(dev, NULL);
        iommu_setup_dma_ops(dev, 0, U64_MAX);
}

static void intel_iommu_get_resv_regions(struct device *device,
                                         struct list_head *head)
{
        int prot = DMA_PTE_READ | DMA_PTE_WRITE;
        struct iommu_resv_region *reg;
        struct dmar_rmrr_unit *rmrr;
        struct device *i_dev;
        int i;

        rcu_read_lock();
        for_each_rmrr_units(rmrr) {
                for_each_active_dev_scope(rmrr->devices, rmrr->devices_cnt,
                                          i, i_dev) {
                        struct iommu_resv_region *resv;
                        enum iommu_resv_type type;
                        size_t length;

                        if (i_dev != device &&
                            !is_downstream_to_pci_bridge(device, i_dev))
                                continue;

                        length = rmrr->end_address - rmrr->base_address + 1;

                        type = device_rmrr_is_relaxable(device) ?
                                IOMMU_RESV_DIRECT_RELAXABLE : IOMMU_RESV_DIRECT;

                        resv = iommu_alloc_resv_region(rmrr->base_address,
                                                       length, prot, type,
                                                       GFP_ATOMIC);
                        if (!resv)
                                break;

                        list_add_tail(&resv->list, head);
                }
        }
        rcu_read_unlock();

#ifdef CONFIG_INTEL_IOMMU_FLOPPY_WA
        if (dev_is_pci(device)) {
                struct pci_dev *pdev = to_pci_dev(device);

                if ((pdev->class >> 8) == PCI_CLASS_BRIDGE_ISA) {
                        reg = iommu_alloc_resv_region(0, 1UL << 24, prot,
                                        IOMMU_RESV_DIRECT_RELAXABLE,
                                        GFP_KERNEL);
                        if (reg)
                                list_add_tail(&reg->list, head);
                }
        }
#endif /* CONFIG_INTEL_IOMMU_FLOPPY_WA */

        reg = iommu_alloc_resv_region(IOAPIC_RANGE_START,
                                      IOAPIC_RANGE_END - IOAPIC_RANGE_START + 1,
                                      0, IOMMU_RESV_MSI, GFP_KERNEL);
        if (!reg)
                return;
        list_add_tail(&reg->list, head);
}

static struct iommu_group *intel_iommu_device_group(struct device *dev)
{
        if (dev_is_pci(dev))
                return pci_device_group(dev);
        return generic_device_group(dev);
}

static int intel_iommu_enable_sva(struct device *dev)
{
        struct device_domain_info *info = dev_iommu_priv_get(dev);
        struct intel_iommu *iommu;

        if (!info || dmar_disabled)
                return -EINVAL;

        iommu = info->iommu;
        if (!iommu)
                return -EINVAL;

        if (!(iommu->flags & VTD_FLAG_SVM_CAPABLE))
                return -ENODEV;

        if (!info->pasid_enabled || !info->ats_enabled)
                return -EINVAL;

        /*
         * Devices having device-specific I/O fault handling should not
         * support PCI/PRI. The IOMMU side has no means to check the
         * capability of device-specific IOPF.  Therefore, IOMMU can only
         * default that if the device driver enables SVA on a non-PRI
         * device, it will handle IOPF in its own way.
         */
        if (!info->pri_supported)
                return 0;

        /* Devices supporting PRI should have it enabled. */
        if (!info->pri_enabled)
                return -EINVAL;

        return 0;
}

static int intel_iommu_enable_iopf(struct device *dev)
{
        struct pci_dev *pdev = dev_is_pci(dev) ? to_pci_dev(dev) : NULL;
        struct device_domain_info *info = dev_iommu_priv_get(dev);
        struct intel_iommu *iommu;
        int ret;

        if (!pdev || !info || !info->ats_enabled || !info->pri_supported)
                return -ENODEV;

        if (info->pri_enabled)
                return -EBUSY;

        iommu = info->iommu;
        if (!iommu)
                return -EINVAL;

        /* PASID is required in PRG Response Message. */
        if (info->pasid_enabled && !pci_prg_resp_pasid_required(pdev))
                return -EINVAL;

        ret = pci_reset_pri(pdev);
        if (ret)
                return ret;

        ret = iopf_queue_add_device(iommu->iopf_queue, dev);
        if (ret)
                return ret;

        ret = pci_enable_pri(pdev, PRQ_DEPTH);
        if (ret) {
                iopf_queue_remove_device(iommu->iopf_queue, dev);
                return ret;
        }

        info->pri_enabled = 1;

        return 0;
}

static int intel_iommu_disable_iopf(struct device *dev)
{
        struct device_domain_info *info = dev_iommu_priv_get(dev);
        struct intel_iommu *iommu = info->iommu;

        if (!info->pri_enabled)
                return -EINVAL;

        /*
         * PCIe spec states that by clearing PRI enable bit, the Page
         * Request Interface will not issue new page requests, but has
         * outstanding page requests that have been transmitted or are
         * queued for transmission. This is supposed to be called after
         * the device driver has stopped DMA, all PASIDs have been
         * unbound and the outstanding PRQs have been drained.
         */
        pci_disable_pri(to_pci_dev(dev));
        info->pri_enabled = 0;
        iopf_queue_remove_device(iommu->iopf_queue, dev);

        return 0;
}

static int
intel_iommu_dev_enable_feat(struct device *dev, enum iommu_dev_features feat)
{
        switch (feat) {
        case IOMMU_DEV_FEAT_IOPF:
                return intel_iommu_enable_iopf(dev);

        case IOMMU_DEV_FEAT_SVA:
                return intel_iommu_enable_sva(dev);

        default:
                return -ENODEV;
        }
}

static int
intel_iommu_dev_disable_feat(struct device *dev, enum iommu_dev_features feat)
{
        switch (feat) {
        case IOMMU_DEV_FEAT_IOPF:
                return intel_iommu_disable_iopf(dev);

        case IOMMU_DEV_FEAT_SVA:
                return 0;

        default:
                return -ENODEV;
        }
}

static bool intel_iommu_is_attach_deferred(struct device *dev)
{
        struct device_domain_info *info = dev_iommu_priv_get(dev);

        return translation_pre_enabled(info->iommu) && !info->domain;
}

/*
 * Check that the device does not live on an external facing PCI port that is
 * marked as untrusted. Such devices should not be able to apply quirks and
 * thus not be able to bypass the IOMMU restrictions.
 */
static bool risky_device(struct pci_dev *pdev)
{
        if (pdev->untrusted) {
                pci_info(pdev,
                         "Skipping IOMMU quirk for dev [%04X:%04X] on untrusted PCI link\n",
                         pdev->vendor, pdev->device);
                pci_info(pdev, "Please check with your BIOS/Platform vendor about this\n");
                return true;
        }
        return false;
}

static int intel_iommu_iotlb_sync_map(struct iommu_domain *domain,
                                      unsigned long iova, size_t size)
{
        struct dmar_domain *dmar_domain = to_dmar_domain(domain);
        unsigned long pages = aligned_nrpages(iova, size);
        unsigned long pfn = iova >> VTD_PAGE_SHIFT;
        struct iommu_domain_info *info;
        unsigned long i;

        xa_for_each(&dmar_domain->iommu_array, i, info)
                __mapping_notify_one(info->iommu, dmar_domain, pfn, pages);
        return 0;
}

static void intel_iommu_remove_dev_pasid(struct device *dev, ioasid_t pasid)
{
        struct device_domain_info *info = dev_iommu_priv_get(dev);
        struct dev_pasid_info *curr, *dev_pasid = NULL;
        struct intel_iommu *iommu = info->iommu;
        struct dmar_domain *dmar_domain;
        struct iommu_domain *domain;
        unsigned long flags;

        domain = iommu_get_domain_for_dev_pasid(dev, pasid, 0);
        if (WARN_ON_ONCE(!domain))
                goto out_tear_down;

        /*
         * The SVA implementation needs to handle its own stuffs like the mm
         * notification. Before consolidating that code into iommu core, let
         * the intel sva code handle it.
         */
        if (domain->type == IOMMU_DOMAIN_SVA) {
                intel_svm_remove_dev_pasid(dev, pasid);
                goto out_tear_down;
        }

        dmar_domain = to_dmar_domain(domain);
        spin_lock_irqsave(&dmar_domain->lock, flags);
        list_for_each_entry(curr, &dmar_domain->dev_pasids, link_domain) {
                if (curr->dev == dev && curr->pasid == pasid) {
                        list_del(&curr->link_domain);
                        dev_pasid = curr;
                        break;
                }
        }
        WARN_ON_ONCE(!dev_pasid);
        spin_unlock_irqrestore(&dmar_domain->lock, flags);

        domain_detach_iommu(dmar_domain, iommu);
        intel_iommu_debugfs_remove_dev_pasid(dev_pasid);
        kfree(dev_pasid);
out_tear_down:
        intel_pasid_tear_down_entry(iommu, dev, pasid, false);
        intel_drain_pasid_prq(dev, pasid);
}

static int intel_iommu_set_dev_pasid(struct iommu_domain *domain,
                                     struct device *dev, ioasid_t pasid)
{
        struct device_domain_info *info = dev_iommu_priv_get(dev);
        struct dmar_domain *dmar_domain = to_dmar_domain(domain);
        struct intel_iommu *iommu = info->iommu;
        struct dev_pasid_info *dev_pasid;
        unsigned long flags;
        int ret;

        if (!pasid_supported(iommu) || dev_is_real_dma_subdevice(dev))
                return -EOPNOTSUPP;

        if (domain->dirty_ops)
                return -EINVAL;

        if (context_copied(iommu, info->bus, info->devfn))
                return -EBUSY;

        ret = prepare_domain_attach_device(domain, dev);
        if (ret)
                return ret;

        dev_pasid = kzalloc(sizeof(*dev_pasid), GFP_KERNEL);
        if (!dev_pasid)
                return -ENOMEM;

        ret = domain_attach_iommu(dmar_domain, iommu);
        if (ret)
                goto out_free;

        if (domain_type_is_si(dmar_domain))
                ret = intel_pasid_setup_pass_through(iommu, dev, pasid);
        else if (dmar_domain->use_first_level)
                ret = domain_setup_first_level(iommu, dmar_domain,
                                               dev, pasid);
        else
                ret = intel_pasid_setup_second_level(iommu, dmar_domain,
                                                     dev, pasid);
        if (ret)
                goto out_detach_iommu;

        dev_pasid->dev = dev;
        dev_pasid->pasid = pasid;
        spin_lock_irqsave(&dmar_domain->lock, flags);
        list_add(&dev_pasid->link_domain, &dmar_domain->dev_pasids);
        spin_unlock_irqrestore(&dmar_domain->lock, flags);

        if (domain->type & __IOMMU_DOMAIN_PAGING)
                intel_iommu_debugfs_create_dev_pasid(dev_pasid);

        return 0;
out_detach_iommu:
        domain_detach_iommu(dmar_domain, iommu);
out_free:
        kfree(dev_pasid);
        return ret;
}

static void *intel_iommu_hw_info(struct device *dev, u32 *length, u32 *type)
{
        struct device_domain_info *info = dev_iommu_priv_get(dev);
        struct intel_iommu *iommu = info->iommu;
        struct iommu_hw_info_vtd *vtd;

        vtd = kzalloc(sizeof(*vtd), GFP_KERNEL);
        if (!vtd)
                return ERR_PTR(-ENOMEM);

        vtd->flags = IOMMU_HW_INFO_VTD_ERRATA_772415_SPR17;
        vtd->cap_reg = iommu->cap;
        vtd->ecap_reg = iommu->ecap;
        *length = sizeof(*vtd);
        *type = IOMMU_HW_INFO_TYPE_INTEL_VTD;
        return vtd;
}

/*
 * Set dirty tracking for the device list of a domain. The caller must
 * hold the domain->lock when calling it.
 */
static int device_set_dirty_tracking(struct list_head *devices, bool enable)
{
        struct device_domain_info *info;
        int ret = 0;

        list_for_each_entry(info, devices, link) {
                ret = intel_pasid_setup_dirty_tracking(info->iommu, info->dev,
                                                       IOMMU_NO_PASID, enable);
                if (ret)
                        break;
        }

        return ret;
}

static int parent_domain_set_dirty_tracking(struct dmar_domain *domain,
                                            bool enable)
{
        struct dmar_domain *s1_domain;
        unsigned long flags;
        int ret;

        spin_lock(&domain->s1_lock);
        list_for_each_entry(s1_domain, &domain->s1_domains, s2_link) {
                spin_lock_irqsave(&s1_domain->lock, flags);
                ret = device_set_dirty_tracking(&s1_domain->devices, enable);
                spin_unlock_irqrestore(&s1_domain->lock, flags);
                if (ret)
                        goto err_unwind;
        }
        spin_unlock(&domain->s1_lock);
        return 0;

err_unwind:
        list_for_each_entry(s1_domain, &domain->s1_domains, s2_link) {
                spin_lock_irqsave(&s1_domain->lock, flags);
                device_set_dirty_tracking(&s1_domain->devices,
                                          domain->dirty_tracking);
                spin_unlock_irqrestore(&s1_domain->lock, flags);
        }
        spin_unlock(&domain->s1_lock);
        return ret;
}

static int intel_iommu_set_dirty_tracking(struct iommu_domain *domain,
                                          bool enable)
{
        struct dmar_domain *dmar_domain = to_dmar_domain(domain);
        int ret;

        spin_lock(&dmar_domain->lock);
        if (dmar_domain->dirty_tracking == enable)
                goto out_unlock;

        ret = device_set_dirty_tracking(&dmar_domain->devices, enable);
        if (ret)
                goto err_unwind;

        if (dmar_domain->nested_parent) {
                ret = parent_domain_set_dirty_tracking(dmar_domain, enable);
                if (ret)
                        goto err_unwind;
        }

        dmar_domain->dirty_tracking = enable;
out_unlock:
        spin_unlock(&dmar_domain->lock);

        return 0;

err_unwind:
        device_set_dirty_tracking(&dmar_domain->devices,
                                  dmar_domain->dirty_tracking);
        spin_unlock(&dmar_domain->lock);
        return ret;
}

static int intel_iommu_read_and_clear_dirty(struct iommu_domain *domain,
                                            unsigned long iova, size_t size,
                                            unsigned long flags,
                                            struct iommu_dirty_bitmap *dirty)
{
        struct dmar_domain *dmar_domain = to_dmar_domain(domain);
        unsigned long end = iova + size - 1;
        unsigned long pgsize;

        /*
         * IOMMUFD core calls into a dirty tracking disabled domain without an
         * IOVA bitmap set in order to clean dirty bits in all PTEs that might
         * have occurred when we stopped dirty tracking. This ensures that we
         * never inherit dirtied bits from a previous cycle.
         */
        if (!dmar_domain->dirty_tracking && dirty->bitmap)
                return -EINVAL;

        do {
                struct dma_pte *pte;
                int lvl = 0;

                pte = pfn_to_dma_pte(dmar_domain, iova >> VTD_PAGE_SHIFT, &lvl,
                                     GFP_ATOMIC);
                pgsize = level_size(lvl) << VTD_PAGE_SHIFT;
                if (!pte || !dma_pte_present(pte)) {
                        iova += pgsize;
                        continue;
                }

                if (dma_sl_pte_test_and_clear_dirty(pte, flags))
                        iommu_dirty_bitmap_record(dirty, iova, pgsize);
                iova += pgsize;
        } while (iova < end);

        return 0;
}

static const struct iommu_dirty_ops intel_dirty_ops = {
        .set_dirty_tracking = intel_iommu_set_dirty_tracking,
        .read_and_clear_dirty = intel_iommu_read_and_clear_dirty,
};

const struct iommu_ops intel_iommu_ops = {
        .blocked_domain         = &blocking_domain,
        .release_domain         = &blocking_domain,
        .capable                = intel_iommu_capable,
        .hw_info                = intel_iommu_hw_info,
        .domain_alloc           = intel_iommu_domain_alloc,
        .domain_alloc_user      = intel_iommu_domain_alloc_user,
        .probe_device           = intel_iommu_probe_device,
        .probe_finalize         = intel_iommu_probe_finalize,
        .release_device         = intel_iommu_release_device,
        .get_resv_regions       = intel_iommu_get_resv_regions,
        .device_group           = intel_iommu_device_group,
        .dev_enable_feat        = intel_iommu_dev_enable_feat,
        .dev_disable_feat       = intel_iommu_dev_disable_feat,
        .is_attach_deferred     = intel_iommu_is_attach_deferred,
        .def_domain_type        = device_def_domain_type,
        .remove_dev_pasid       = intel_iommu_remove_dev_pasid,
        .pgsize_bitmap          = SZ_4K,
#ifdef CONFIG_INTEL_IOMMU_SVM
        .page_response          = intel_svm_page_response,
#endif
        .default_domain_ops = &(const struct iommu_domain_ops) {
                .attach_dev             = intel_iommu_attach_device,
                .set_dev_pasid          = intel_iommu_set_dev_pasid,
                .map_pages              = intel_iommu_map_pages,
                .unmap_pages            = intel_iommu_unmap_pages,
                .iotlb_sync_map         = intel_iommu_iotlb_sync_map,
                .flush_iotlb_all        = intel_flush_iotlb_all,
                .iotlb_sync             = intel_iommu_tlb_sync,
                .iova_to_phys           = intel_iommu_iova_to_phys,
                .free                   = intel_iommu_domain_free,
                .enforce_cache_coherency = intel_iommu_enforce_cache_coherency,
        }
};

static void quirk_iommu_igfx(struct pci_dev *dev)
{
        if (risky_device(dev))
                return;

        pci_info(dev, "Disabling IOMMU for graphics on this chipset\n");
        dmar_map_gfx = 0;
}

/* G4x/GM45 integrated gfx dmar support is totally busted. */
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x2a40, quirk_iommu_igfx);
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x2e00, quirk_iommu_igfx);
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x2e10, quirk_iommu_igfx);
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x2e20, quirk_iommu_igfx);
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x2e30, quirk_iommu_igfx);
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x2e40, quirk_iommu_igfx);
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x2e90, quirk_iommu_igfx);

/* Broadwell igfx malfunctions with dmar */
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x1606, quirk_iommu_igfx);
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x160B, quirk_iommu_igfx);
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x160E, quirk_iommu_igfx);
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x1602, quirk_iommu_igfx);
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x160A, quirk_iommu_igfx);
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x160D, quirk_iommu_igfx);
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x1616, quirk_iommu_igfx);
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x161B, quirk_iommu_igfx);
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x161E, quirk_iommu_igfx);
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x1612, quirk_iommu_igfx);
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x161A, quirk_iommu_igfx);
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x161D, quirk_iommu_igfx);
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x1626, quirk_iommu_igfx);
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x162B, quirk_iommu_igfx);
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x162E, quirk_iommu_igfx);
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x1622, quirk_iommu_igfx);
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x162A, quirk_iommu_igfx);
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x162D, quirk_iommu_igfx);
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x1636, quirk_iommu_igfx);
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x163B, quirk_iommu_igfx);
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x163E, quirk_iommu_igfx);
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x1632, quirk_iommu_igfx);
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x163A, quirk_iommu_igfx);
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x163D, quirk_iommu_igfx);

static void quirk_iommu_rwbf(struct pci_dev *dev)
{
        if (risky_device(dev))
                return;

        /*
         * Mobile 4 Series Chipset neglects to set RWBF capability,
         * but needs it. Same seems to hold for the desktop versions.
         */
        pci_info(dev, "Forcing write-buffer flush capability\n");
        rwbf_quirk = 1;
}

DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x2a40, quirk_iommu_rwbf);
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x2e00, quirk_iommu_rwbf);
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x2e10, quirk_iommu_rwbf);
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x2e20, quirk_iommu_rwbf);
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x2e30, quirk_iommu_rwbf);
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x2e40, quirk_iommu_rwbf);
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x2e90, quirk_iommu_rwbf);

#define GGC 0x52
#define GGC_MEMORY_SIZE_MASK    (0xf << 8)
#define GGC_MEMORY_SIZE_NONE    (0x0 << 8)
#define GGC_MEMORY_SIZE_1M      (0x1 << 8)
#define GGC_MEMORY_SIZE_2M      (0x3 << 8)
#define GGC_MEMORY_VT_ENABLED   (0x8 << 8)
#define GGC_MEMORY_SIZE_2M_VT   (0x9 << 8)
#define GGC_MEMORY_SIZE_3M_VT   (0xa << 8)
#define GGC_MEMORY_SIZE_4M_VT   (0xb << 8)

static void quirk_calpella_no_shadow_gtt(struct pci_dev *dev)
{
        unsigned short ggc;

        if (risky_device(dev))
                return;

        if (pci_read_config_word(dev, GGC, &ggc))
                return;

        if (!(ggc & GGC_MEMORY_VT_ENABLED)) {
                pci_info(dev, "BIOS has allocated no shadow GTT; disabling IOMMU for graphics\n");
                dmar_map_gfx = 0;
        } else if (dmar_map_gfx) {
                /* we have to ensure the gfx device is idle before we flush */
                pci_info(dev, "Disabling batched IOTLB flush on Ironlake\n");
                iommu_set_dma_strict();
        }
}
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x0040, quirk_calpella_no_shadow_gtt);
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x0044, quirk_calpella_no_shadow_gtt);
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x0062, quirk_calpella_no_shadow_gtt);
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x006a, quirk_calpella_no_shadow_gtt);

static void quirk_igfx_skip_te_disable(struct pci_dev *dev)
{
        unsigned short ver;

        if (!IS_GFX_DEVICE(dev))
                return;

        ver = (dev->device >> 8) & 0xff;
        if (ver != 0x45 && ver != 0x46 && ver != 0x4c &&
            ver != 0x4e && ver != 0x8a && ver != 0x98 &&
            ver != 0x9a && ver != 0xa7 && ver != 0x7d)
                return;

        if (risky_device(dev))
                return;

        pci_info(dev, "Skip IOMMU disabling for graphics\n");
        iommu_skip_te_disable = 1;
}
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, PCI_ANY_ID, quirk_igfx_skip_te_disable);

/* On Tylersburg chipsets, some BIOSes have been known to enable the
   ISOCH DMAR unit for the Azalia sound device, but not give it any
   TLB entries, which causes it to deadlock. Check for that.  We do
   this in a function called from init_dmars(), instead of in a PCI
   quirk, because we don't want to print the obnoxious "BIOS broken"
   message if VT-d is actually disabled.
*/
static void __init check_tylersburg_isoch(void)
{
        struct pci_dev *pdev;
        uint32_t vtisochctrl;

        /* If there's no Azalia in the system anyway, forget it. */
        pdev = pci_get_device(PCI_VENDOR_ID_INTEL, 0x3a3e, NULL);
        if (!pdev)
                return;

        if (risky_device(pdev)) {
                pci_dev_put(pdev);
                return;
        }

        pci_dev_put(pdev);

        /* System Management Registers. Might be hidden, in which case
           we can't do the sanity check. But that's OK, because the
           known-broken BIOSes _don't_ actually hide it, so far. */
        pdev = pci_get_device(PCI_VENDOR_ID_INTEL, 0x342e, NULL);
        if (!pdev)
                return;

        if (risky_device(pdev)) {
                pci_dev_put(pdev);
                return;
        }

        if (pci_read_config_dword(pdev, 0x188, &vtisochctrl)) {
                pci_dev_put(pdev);
                return;
        }

        pci_dev_put(pdev);

        /* If Azalia DMA is routed to the non-isoch DMAR unit, fine. */
        if (vtisochctrl & 1)
                return;

        /* Drop all bits other than the number of TLB entries */
        vtisochctrl &= 0x1c;

        /* If we have the recommended number of TLB entries (16), fine. */
        if (vtisochctrl == 0x10)
                return;

        /* Zero TLB entries? You get to ride the short bus to school. */
        if (!vtisochctrl) {
                WARN(1, "Your BIOS is broken; DMA routed to ISOCH DMAR unit but no TLB space.\n"
                     "BIOS vendor: %s; Ver: %s; Product Version: %s\n",
                     dmi_get_system_info(DMI_BIOS_VENDOR),
                     dmi_get_system_info(DMI_BIOS_VERSION),
                     dmi_get_system_info(DMI_PRODUCT_VERSION));
                iommu_identity_mapping |= IDENTMAP_AZALIA;
                return;
        }

        pr_warn("Recommended TLB entries for ISOCH unit is 16; your BIOS set %d\n",
               vtisochctrl);
}

/*
 * Here we deal with a device TLB defect where device may inadvertently issue ATS
 * invalidation completion before posted writes initiated with translated address
 * that utilized translations matching the invalidation address range, violating
 * the invalidation completion ordering.
 * Therefore, any use cases that cannot guarantee DMA is stopped before unmap is
 * vulnerable to this defect. In other words, any dTLB invalidation initiated not
 * under the control of the trusted/privileged host device driver must use this
 * quirk.
 * Device TLBs are invalidated under the following six conditions:
 * 1. Device driver does DMA API unmap IOVA
 * 2. Device driver unbind a PASID from a process, sva_unbind_device()
 * 3. PASID is torn down, after PASID cache is flushed. e.g. process
 *    exit_mmap() due to crash
 * 4. Under SVA usage, called by mmu_notifier.invalidate_range() where
 *    VM has to free pages that were unmapped
 * 5. Userspace driver unmaps a DMA buffer
 * 6. Cache invalidation in vSVA usage (upcoming)
 *
 * For #1 and #2, device drivers are responsible for stopping DMA traffic
 * before unmap/unbind. For #3, iommu driver gets mmu_notifier to
 * invalidate TLB the same way as normal user unmap which will use this quirk.
 * The dTLB invalidation after PASID cache flush does not need this quirk.
 *
 * As a reminder, #6 will *NEED* this quirk as we enable nested translation.
 */
void quirk_extra_dev_tlb_flush(struct device_domain_info *info,
                               unsigned long address, unsigned long mask,
                               u32 pasid, u16 qdep)
{
        u16 sid;

        if (likely(!info->dtlb_extra_inval))
                return;

        sid = PCI_DEVID(info->bus, info->devfn);
        if (pasid == IOMMU_NO_PASID) {
                qi_flush_dev_iotlb(info->iommu, sid, info->pfsid,
                                   qdep, address, mask);
        } else {
                qi_flush_dev_iotlb_pasid(info->iommu, sid, info->pfsid,
                                         pasid, qdep, address, mask);
        }
}

#define ecmd_get_status_code(res)       (((res) & 0xff) >> 1)

/*
 * Function to submit a command to the enhanced command interface. The
 * valid enhanced command descriptions are defined in Table 47 of the
 * VT-d spec. The VT-d hardware implementation may support some but not
 * all commands, which can be determined by checking the Enhanced
 * Command Capability Register.
 *
 * Return values:
 *  - 0: Command successful without any error;
 *  - Negative: software error value;
 *  - Nonzero positive: failure status code defined in Table 48.
 */
int ecmd_submit_sync(struct intel_iommu *iommu, u8 ecmd, u64 oa, u64 ob)
{
        unsigned long flags;
        u64 res;
        int ret;

        if (!cap_ecmds(iommu->cap))
                return -ENODEV;

        raw_spin_lock_irqsave(&iommu->register_lock, flags);

        res = dmar_readq(iommu->reg + DMAR_ECRSP_REG);
        if (res & DMA_ECMD_ECRSP_IP) {
                ret = -EBUSY;
                goto err;
        }

        /*
         * Unconditionally write the operand B, because
         * - There is no side effect if an ecmd doesn't require an
         *   operand B, but we set the register to some value.
         * - It's not invoked in any critical path. The extra MMIO
         *   write doesn't bring any performance concerns.
         */
        dmar_writeq(iommu->reg + DMAR_ECEO_REG, ob);
        dmar_writeq(iommu->reg + DMAR_ECMD_REG, ecmd | (oa << DMA_ECMD_OA_SHIFT));

        IOMMU_WAIT_OP(iommu, DMAR_ECRSP_REG, dmar_readq,
                      !(res & DMA_ECMD_ECRSP_IP), res);

        if (res & DMA_ECMD_ECRSP_IP) {
                ret = -ETIMEDOUT;
                goto err;
        }

        ret = ecmd_get_status_code(res);
err:
        raw_spin_unlock_irqrestore(&iommu->register_lock, flags);

        return ret;
}