1 // SPDX-License-Identifier: GPL-2.0
3 * Volume Management Device driver
4 * Copyright (c) 2015, Intel Corporation.
7 #include <linux/device.h>
8 #include <linux/interrupt.h>
10 #include <linux/kernel.h>
11 #include <linux/module.h>
12 #include <linux/msi.h>
13 #include <linux/pci.h>
14 #include <linux/srcu.h>
15 #include <linux/rculist.h>
16 #include <linux/rcupdate.h>
18 #include <asm/irqdomain.h>
19 #include <asm/device.h>
21 #include <asm/msidef.h>
27 #define PCI_REG_VMCAP 0x40
28 #define BUS_RESTRICT_CAP(vmcap) (vmcap & 0x1)
29 #define PCI_REG_VMCONFIG 0x44
30 #define BUS_RESTRICT_CFG(vmcfg) ((vmcfg >> 8) & 0x3)
31 #define PCI_REG_VMLOCK 0x70
32 #define MB2_SHADOW_EN(vmlock) (vmlock & 0x2)
34 #define MB2_SHADOW_OFFSET 0x2000
35 #define MB2_SHADOW_SIZE 16
39 * Device may contain registers which hint the physical location of the
40 * membars, in order to allow proper address translation during
41 * resource assignment to enable guest virtualization
43 VMD_FEAT_HAS_MEMBAR_SHADOW = (1 << 0),
46 * Device may provide root port configuration information which limits
49 VMD_FEAT_HAS_BUS_RESTRICTIONS = (1 << 1),
52 * Device contains physical location shadow registers in
53 * vendor-specific capability space
55 VMD_FEAT_HAS_MEMBAR_SHADOW_VSCAP = (1 << 2),
59 * Lock for manipulating VMD IRQ lists.
61 static DEFINE_RAW_SPINLOCK(list_lock);
64 * struct vmd_irq - private data to map driver IRQ to the VMD shared vector
65 * @node: list item for parent traversal.
66 * @irq: back pointer to parent.
67 * @enabled: true if driver enabled IRQ
68 * @virq: the virtual IRQ value provided to the requesting driver.
70 * Every MSI/MSI-X IRQ requested for a device in a VMD domain will be mapped to
71 * a VMD IRQ using this structure.
74 struct list_head node;
75 struct vmd_irq_list *irq;
81 * struct vmd_irq_list - list of driver requested IRQs mapping to a VMD vector
82 * @irq_list: the list of irq's the VMD one demuxes to.
83 * @srcu: SRCU struct for local synchronization.
84 * @count: number of child IRQs assigned to this vector; used to track
88 struct list_head irq_list;
89 struct srcu_struct srcu;
100 struct vmd_irq_list *irqs;
102 struct pci_sysdata sysdata;
103 struct resource resources[3];
104 struct irq_domain *irq_domain;
109 static inline struct vmd_dev *vmd_from_bus(struct pci_bus *bus)
111 return container_of(bus->sysdata, struct vmd_dev, sysdata);
114 static inline unsigned int index_from_irqs(struct vmd_dev *vmd,
115 struct vmd_irq_list *irqs)
117 return irqs - vmd->irqs;
121 * Drivers managing a device in a VMD domain allocate their own IRQs as before,
122 * but the MSI entry for the hardware it's driving will be programmed with a
123 * destination ID for the VMD MSI-X table. The VMD muxes interrupts in its
124 * domain into one of its own, and the VMD driver de-muxes these for the
125 * handlers sharing that VMD IRQ. The vmd irq_domain provides the operations
126 * and irq_chip to set this up.
128 static void vmd_compose_msi_msg(struct irq_data *data, struct msi_msg *msg)
130 struct vmd_irq *vmdirq = data->chip_data;
131 struct vmd_irq_list *irq = vmdirq->irq;
132 struct vmd_dev *vmd = irq_data_get_irq_handler_data(data);
134 msg->address_hi = MSI_ADDR_BASE_HI;
135 msg->address_lo = MSI_ADDR_BASE_LO |
136 MSI_ADDR_DEST_ID(index_from_irqs(vmd, irq));
141 * We rely on MSI_FLAG_USE_DEF_CHIP_OPS to set the IRQ mask/unmask ops.
143 static void vmd_irq_enable(struct irq_data *data)
145 struct vmd_irq *vmdirq = data->chip_data;
148 raw_spin_lock_irqsave(&list_lock, flags);
149 WARN_ON(vmdirq->enabled);
150 list_add_tail_rcu(&vmdirq->node, &vmdirq->irq->irq_list);
151 vmdirq->enabled = true;
152 raw_spin_unlock_irqrestore(&list_lock, flags);
154 data->chip->irq_unmask(data);
157 static void vmd_irq_disable(struct irq_data *data)
159 struct vmd_irq *vmdirq = data->chip_data;
162 data->chip->irq_mask(data);
164 raw_spin_lock_irqsave(&list_lock, flags);
165 if (vmdirq->enabled) {
166 list_del_rcu(&vmdirq->node);
167 vmdirq->enabled = false;
169 raw_spin_unlock_irqrestore(&list_lock, flags);
173 * XXX: Stubbed until we develop acceptable way to not create conflicts with
174 * other devices sharing the same vector.
176 static int vmd_irq_set_affinity(struct irq_data *data,
177 const struct cpumask *dest, bool force)
182 static struct irq_chip vmd_msi_controller = {
184 .irq_enable = vmd_irq_enable,
185 .irq_disable = vmd_irq_disable,
186 .irq_compose_msi_msg = vmd_compose_msi_msg,
187 .irq_set_affinity = vmd_irq_set_affinity,
190 static irq_hw_number_t vmd_get_hwirq(struct msi_domain_info *info,
191 msi_alloc_info_t *arg)
197 * XXX: We can be even smarter selecting the best IRQ once we solve the
200 static struct vmd_irq_list *vmd_next_irq(struct vmd_dev *vmd, struct msi_desc *desc)
205 if (vmd->msix_count == 1)
206 return &vmd->irqs[0];
209 * White list for fast-interrupt handlers. All others will share the
210 * "slow" interrupt vector.
212 switch (msi_desc_to_pci_dev(desc)->class) {
213 case PCI_CLASS_STORAGE_EXPRESS:
216 return &vmd->irqs[0];
219 raw_spin_lock_irqsave(&list_lock, flags);
220 for (i = 1; i < vmd->msix_count; i++)
221 if (vmd->irqs[i].count < vmd->irqs[best].count)
223 vmd->irqs[best].count++;
224 raw_spin_unlock_irqrestore(&list_lock, flags);
226 return &vmd->irqs[best];
229 static int vmd_msi_init(struct irq_domain *domain, struct msi_domain_info *info,
230 unsigned int virq, irq_hw_number_t hwirq,
231 msi_alloc_info_t *arg)
233 struct msi_desc *desc = arg->desc;
234 struct vmd_dev *vmd = vmd_from_bus(msi_desc_to_pci_dev(desc)->bus);
235 struct vmd_irq *vmdirq = kzalloc(sizeof(*vmdirq), GFP_KERNEL);
236 unsigned int index, vector;
241 INIT_LIST_HEAD(&vmdirq->node);
242 vmdirq->irq = vmd_next_irq(vmd, desc);
244 index = index_from_irqs(vmd, vmdirq->irq);
245 vector = pci_irq_vector(vmd->dev, index);
247 irq_domain_set_info(domain, virq, vector, info->chip, vmdirq,
248 handle_untracked_irq, vmd, NULL);
252 static void vmd_msi_free(struct irq_domain *domain,
253 struct msi_domain_info *info, unsigned int virq)
255 struct vmd_irq *vmdirq = irq_get_chip_data(virq);
258 synchronize_srcu(&vmdirq->irq->srcu);
260 /* XXX: Potential optimization to rebalance */
261 raw_spin_lock_irqsave(&list_lock, flags);
262 vmdirq->irq->count--;
263 raw_spin_unlock_irqrestore(&list_lock, flags);
268 static int vmd_msi_prepare(struct irq_domain *domain, struct device *dev,
269 int nvec, msi_alloc_info_t *arg)
271 struct pci_dev *pdev = to_pci_dev(dev);
272 struct vmd_dev *vmd = vmd_from_bus(pdev->bus);
274 if (nvec > vmd->msix_count)
275 return vmd->msix_count;
277 memset(arg, 0, sizeof(*arg));
281 static void vmd_set_desc(msi_alloc_info_t *arg, struct msi_desc *desc)
286 static struct msi_domain_ops vmd_msi_domain_ops = {
287 .get_hwirq = vmd_get_hwirq,
288 .msi_init = vmd_msi_init,
289 .msi_free = vmd_msi_free,
290 .msi_prepare = vmd_msi_prepare,
291 .set_desc = vmd_set_desc,
294 static struct msi_domain_info vmd_msi_domain_info = {
295 .flags = MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS |
297 .ops = &vmd_msi_domain_ops,
298 .chip = &vmd_msi_controller,
301 static char __iomem *vmd_cfg_addr(struct vmd_dev *vmd, struct pci_bus *bus,
302 unsigned int devfn, int reg, int len)
304 char __iomem *addr = vmd->cfgbar +
305 ((bus->number - vmd->busn_start) << 20) +
308 if ((addr - vmd->cfgbar) + len >=
309 resource_size(&vmd->dev->resource[VMD_CFGBAR]))
316 * CPU may deadlock if config space is not serialized on some versions of this
317 * hardware, so all config space access is done under a spinlock.
319 static int vmd_pci_read(struct pci_bus *bus, unsigned int devfn, int reg,
322 struct vmd_dev *vmd = vmd_from_bus(bus);
323 char __iomem *addr = vmd_cfg_addr(vmd, bus, devfn, reg, len);
330 spin_lock_irqsave(&vmd->cfg_lock, flags);
333 *value = readb(addr);
336 *value = readw(addr);
339 *value = readl(addr);
345 spin_unlock_irqrestore(&vmd->cfg_lock, flags);
350 * VMD h/w converts non-posted config writes to posted memory writes. The
351 * read-back in this function forces the completion so it returns only after
352 * the config space was written, as expected.
354 static int vmd_pci_write(struct pci_bus *bus, unsigned int devfn, int reg,
357 struct vmd_dev *vmd = vmd_from_bus(bus);
358 char __iomem *addr = vmd_cfg_addr(vmd, bus, devfn, reg, len);
365 spin_lock_irqsave(&vmd->cfg_lock, flags);
383 spin_unlock_irqrestore(&vmd->cfg_lock, flags);
387 static struct pci_ops vmd_ops = {
388 .read = vmd_pci_read,
389 .write = vmd_pci_write,
392 static void vmd_attach_resources(struct vmd_dev *vmd)
394 vmd->dev->resource[VMD_MEMBAR1].child = &vmd->resources[1];
395 vmd->dev->resource[VMD_MEMBAR2].child = &vmd->resources[2];
398 static void vmd_detach_resources(struct vmd_dev *vmd)
400 vmd->dev->resource[VMD_MEMBAR1].child = NULL;
401 vmd->dev->resource[VMD_MEMBAR2].child = NULL;
405 * VMD domains start at 0x10000 to not clash with ACPI _SEG domains.
406 * Per ACPI r6.0, sec 6.5.6, _SEG returns an integer, of which the lower
407 * 16 bits are the PCI Segment Group (domain) number. Other bits are
408 * currently reserved.
410 static int vmd_find_free_domain(void)
413 struct pci_bus *bus = NULL;
415 while ((bus = pci_find_next_bus(bus)) != NULL)
416 domain = max_t(int, domain, pci_domain_nr(bus));
420 static int vmd_enable_domain(struct vmd_dev *vmd, unsigned long features)
422 struct pci_sysdata *sd = &vmd->sysdata;
423 struct fwnode_handle *fn;
424 struct resource *res;
427 LIST_HEAD(resources);
428 resource_size_t offset[2] = {0};
429 resource_size_t membar2_offset = 0x2000;
430 struct pci_bus *child;
433 * Shadow registers may exist in certain VMD device ids which allow
434 * guests to correctly assign host physical addresses to the root ports
435 * and child devices. These registers will either return the host value
436 * or 0, depending on an enable bit in the VMD device.
438 if (features & VMD_FEAT_HAS_MEMBAR_SHADOW) {
442 membar2_offset = MB2_SHADOW_OFFSET + MB2_SHADOW_SIZE;
443 ret = pci_read_config_dword(vmd->dev, PCI_REG_VMLOCK, &vmlock);
444 if (ret || vmlock == ~0)
447 if (MB2_SHADOW_EN(vmlock)) {
448 void __iomem *membar2;
450 membar2 = pci_iomap(vmd->dev, VMD_MEMBAR2, 0);
453 offset[0] = vmd->dev->resource[VMD_MEMBAR1].start -
454 (readq(membar2 + MB2_SHADOW_OFFSET) &
455 PCI_BASE_ADDRESS_MEM_MASK);
456 offset[1] = vmd->dev->resource[VMD_MEMBAR2].start -
457 (readq(membar2 + MB2_SHADOW_OFFSET + 8) &
458 PCI_BASE_ADDRESS_MEM_MASK);
459 pci_iounmap(vmd->dev, membar2);
463 if (features & VMD_FEAT_HAS_MEMBAR_SHADOW_VSCAP) {
464 int pos = pci_find_capability(vmd->dev, PCI_CAP_ID_VNDR);
467 pci_read_config_dword(vmd->dev, pos + 4, ®);
470 if (pos && reg == 0x53484457) {
471 pci_read_config_dword(vmd->dev, pos + 8, ®);
472 pci_read_config_dword(vmd->dev, pos + 12, ®u);
473 offset[0] = vmd->dev->resource[VMD_MEMBAR1].start -
474 (((u64) regu << 32 | reg) &
475 PCI_BASE_ADDRESS_MEM_MASK);
477 pci_read_config_dword(vmd->dev, pos + 16, ®);
478 pci_read_config_dword(vmd->dev, pos + 20, ®u);
479 offset[1] = vmd->dev->resource[VMD_MEMBAR2].start -
480 (((u64) regu << 32 | reg) &
481 PCI_BASE_ADDRESS_MEM_MASK);
486 * Certain VMD devices may have a root port configuration option which
487 * limits the bus range to between 0-127, 128-255, or 224-255
489 if (features & VMD_FEAT_HAS_BUS_RESTRICTIONS) {
492 pci_read_config_word(vmd->dev, PCI_REG_VMCAP, ®16);
493 if (BUS_RESTRICT_CAP(reg16)) {
494 pci_read_config_word(vmd->dev, PCI_REG_VMCONFIG,
497 switch (BUS_RESTRICT_CFG(reg16)) {
499 vmd->busn_start = 128;
502 vmd->busn_start = 224;
505 pci_err(vmd->dev, "Unknown Bus Offset Setting\n");
513 res = &vmd->dev->resource[VMD_CFGBAR];
514 vmd->resources[0] = (struct resource) {
515 .name = "VMD CFGBAR",
516 .start = vmd->busn_start,
517 .end = vmd->busn_start + (resource_size(res) >> 20) - 1,
518 .flags = IORESOURCE_BUS | IORESOURCE_PCI_FIXED,
522 * If the window is below 4GB, clear IORESOURCE_MEM_64 so we can
523 * put 32-bit resources in the window.
525 * There's no hardware reason why a 64-bit window *couldn't*
526 * contain a 32-bit resource, but pbus_size_mem() computes the
527 * bridge window size assuming a 64-bit window will contain no
528 * 32-bit resources. __pci_assign_resource() enforces that
529 * artificial restriction to make sure everything will fit.
531 * The only way we could use a 64-bit non-prefetchable MEMBAR is
532 * if its address is <4GB so that we can convert it to a 32-bit
533 * resource. To be visible to the host OS, all VMD endpoints must
534 * be initially configured by platform BIOS, which includes setting
535 * up these resources. We can assume the device is configured
536 * according to the platform needs.
538 res = &vmd->dev->resource[VMD_MEMBAR1];
539 upper_bits = upper_32_bits(res->end);
540 flags = res->flags & ~IORESOURCE_SIZEALIGN;
542 flags &= ~IORESOURCE_MEM_64;
543 vmd->resources[1] = (struct resource) {
544 .name = "VMD MEMBAR1",
551 res = &vmd->dev->resource[VMD_MEMBAR2];
552 upper_bits = upper_32_bits(res->end);
553 flags = res->flags & ~IORESOURCE_SIZEALIGN;
555 flags &= ~IORESOURCE_MEM_64;
556 vmd->resources[2] = (struct resource) {
557 .name = "VMD MEMBAR2",
558 .start = res->start + membar2_offset,
564 sd->vmd_dev = vmd->dev;
565 sd->domain = vmd_find_free_domain();
569 sd->node = pcibus_to_node(vmd->dev->bus);
571 fn = irq_domain_alloc_named_id_fwnode("VMD-MSI", vmd->sysdata.domain);
575 vmd->irq_domain = pci_msi_create_irq_domain(fn, &vmd_msi_domain_info,
577 if (!vmd->irq_domain) {
578 irq_domain_free_fwnode(fn);
582 pci_add_resource(&resources, &vmd->resources[0]);
583 pci_add_resource_offset(&resources, &vmd->resources[1], offset[0]);
584 pci_add_resource_offset(&resources, &vmd->resources[2], offset[1]);
586 vmd->bus = pci_create_root_bus(&vmd->dev->dev, vmd->busn_start,
587 &vmd_ops, sd, &resources);
589 pci_free_resource_list(&resources);
590 irq_domain_remove(vmd->irq_domain);
591 irq_domain_free_fwnode(fn);
595 vmd_attach_resources(vmd);
596 dev_set_msi_domain(&vmd->bus->dev, vmd->irq_domain);
598 pci_scan_child_bus(vmd->bus);
599 pci_assign_unassigned_bus_resources(vmd->bus);
602 * VMD root buses are virtual and don't return true on pci_is_pcie()
603 * and will fail pcie_bus_configure_settings() early. It can instead be
604 * run on each of the real root ports.
606 list_for_each_entry(child, &vmd->bus->children, node)
607 pcie_bus_configure_settings(child);
609 pci_bus_add_devices(vmd->bus);
611 WARN(sysfs_create_link(&vmd->dev->dev.kobj, &vmd->bus->dev.kobj,
612 "domain"), "Can't create symlink to domain\n");
616 static irqreturn_t vmd_irq(int irq, void *data)
618 struct vmd_irq_list *irqs = data;
619 struct vmd_irq *vmdirq;
622 idx = srcu_read_lock(&irqs->srcu);
623 list_for_each_entry_rcu(vmdirq, &irqs->irq_list, node)
624 generic_handle_irq(vmdirq->virq);
625 srcu_read_unlock(&irqs->srcu, idx);
630 static int vmd_probe(struct pci_dev *dev, const struct pci_device_id *id)
635 if (resource_size(&dev->resource[VMD_CFGBAR]) < (1 << 20))
638 vmd = devm_kzalloc(&dev->dev, sizeof(*vmd), GFP_KERNEL);
643 err = pcim_enable_device(dev);
647 vmd->cfgbar = pcim_iomap(dev, VMD_CFGBAR, 0);
652 if (dma_set_mask_and_coherent(&dev->dev, DMA_BIT_MASK(64)) &&
653 dma_set_mask_and_coherent(&dev->dev, DMA_BIT_MASK(32)))
656 vmd->msix_count = pci_msix_vec_count(dev);
657 if (vmd->msix_count < 0)
660 vmd->msix_count = pci_alloc_irq_vectors(dev, 1, vmd->msix_count,
662 if (vmd->msix_count < 0)
663 return vmd->msix_count;
665 vmd->irqs = devm_kcalloc(&dev->dev, vmd->msix_count, sizeof(*vmd->irqs),
670 for (i = 0; i < vmd->msix_count; i++) {
671 err = init_srcu_struct(&vmd->irqs[i].srcu);
675 INIT_LIST_HEAD(&vmd->irqs[i].irq_list);
676 err = devm_request_irq(&dev->dev, pci_irq_vector(dev, i),
677 vmd_irq, IRQF_NO_THREAD,
678 "vmd", &vmd->irqs[i]);
683 spin_lock_init(&vmd->cfg_lock);
684 pci_set_drvdata(dev, vmd);
685 err = vmd_enable_domain(vmd, (unsigned long) id->driver_data);
689 dev_info(&vmd->dev->dev, "Bound to PCI domain %04x\n",
690 vmd->sysdata.domain);
694 static void vmd_cleanup_srcu(struct vmd_dev *vmd)
698 for (i = 0; i < vmd->msix_count; i++)
699 cleanup_srcu_struct(&vmd->irqs[i].srcu);
702 static void vmd_remove(struct pci_dev *dev)
704 struct vmd_dev *vmd = pci_get_drvdata(dev);
705 struct fwnode_handle *fn = vmd->irq_domain->fwnode;
707 sysfs_remove_link(&vmd->dev->dev.kobj, "domain");
708 pci_stop_root_bus(vmd->bus);
709 pci_remove_root_bus(vmd->bus);
710 vmd_cleanup_srcu(vmd);
711 vmd_detach_resources(vmd);
712 irq_domain_remove(vmd->irq_domain);
713 irq_domain_free_fwnode(fn);
716 #ifdef CONFIG_PM_SLEEP
717 static int vmd_suspend(struct device *dev)
719 struct pci_dev *pdev = to_pci_dev(dev);
720 struct vmd_dev *vmd = pci_get_drvdata(pdev);
723 for (i = 0; i < vmd->msix_count; i++)
724 devm_free_irq(dev, pci_irq_vector(pdev, i), &vmd->irqs[i]);
726 pci_save_state(pdev);
730 static int vmd_resume(struct device *dev)
732 struct pci_dev *pdev = to_pci_dev(dev);
733 struct vmd_dev *vmd = pci_get_drvdata(pdev);
736 for (i = 0; i < vmd->msix_count; i++) {
737 err = devm_request_irq(dev, pci_irq_vector(pdev, i),
738 vmd_irq, IRQF_NO_THREAD,
739 "vmd", &vmd->irqs[i]);
744 pci_restore_state(pdev);
748 static SIMPLE_DEV_PM_OPS(vmd_dev_pm_ops, vmd_suspend, vmd_resume);
750 static const struct pci_device_id vmd_ids[] = {
751 {PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_VMD_201D),
752 .driver_data = VMD_FEAT_HAS_MEMBAR_SHADOW_VSCAP,},
753 {PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_VMD_28C0),
754 .driver_data = VMD_FEAT_HAS_MEMBAR_SHADOW |
755 VMD_FEAT_HAS_BUS_RESTRICTIONS,},
756 {PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x467f),
757 .driver_data = VMD_FEAT_HAS_MEMBAR_SHADOW_VSCAP |
758 VMD_FEAT_HAS_BUS_RESTRICTIONS,},
759 {PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x4c3d),
760 .driver_data = VMD_FEAT_HAS_MEMBAR_SHADOW_VSCAP |
761 VMD_FEAT_HAS_BUS_RESTRICTIONS,},
762 {PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_VMD_9A0B),
763 .driver_data = VMD_FEAT_HAS_MEMBAR_SHADOW_VSCAP |
764 VMD_FEAT_HAS_BUS_RESTRICTIONS,},
767 MODULE_DEVICE_TABLE(pci, vmd_ids);
769 static struct pci_driver vmd_drv = {
773 .remove = vmd_remove,
775 .pm = &vmd_dev_pm_ops,
778 module_pci_driver(vmd_drv);
780 MODULE_AUTHOR("Intel Corporation");
781 MODULE_LICENSE("GPL v2");
782 MODULE_VERSION("0.6");