drivers/iommu/intel/svm.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright © 2015 Intel Corporation.
   4  *
   5  * Authors: David Woodhouse <[email protected]>
   6  */
   7
   8 #include <linux/mmu_notifier.h>
   9 #include <linux/sched.h>
  10 #include <linux/sched/mm.h>
  11 #include <linux/slab.h>
  12 #include <linux/rculist.h>
  13 #include <linux/pci.h>
  14 #include <linux/pci-ats.h>
  15 #include <linux/dmar.h>
  16 #include <linux/interrupt.h>
  17 #include <linux/mm_types.h>
  18 #include <linux/xarray.h>
  19 #include <asm/page.h>
  20 #include <asm/fpu/api.h>
  21
  22 #include "iommu.h"
  23 #include "pasid.h"
  24 #include "perf.h"
  25 #include "trace.h"
  26
  27 static irqreturn_t prq_event_thread(int irq, void *d);
  28
  29 static DEFINE_XARRAY_ALLOC(pasid_private_array);
  30 static int pasid_private_add(ioasid_t pasid, void *priv)
  31 {
  32         return xa_alloc(&pasid_private_array, &pasid, priv,
  33                         XA_LIMIT(pasid, pasid), GFP_ATOMIC);
  34 }
  35
  36 static void pasid_private_remove(ioasid_t pasid)
  37 {
  38         xa_erase(&pasid_private_array, pasid);
  39 }
  40
  41 static void *pasid_private_find(ioasid_t pasid)
  42 {
  43         return xa_load(&pasid_private_array, pasid);
  44 }
  45
  46 static struct intel_svm_dev *
  47 svm_lookup_device_by_dev(struct intel_svm *svm, struct device *dev)
  48 {
  49         struct intel_svm_dev *sdev = NULL, *t;
  50
  51         rcu_read_lock();
  52         list_for_each_entry_rcu(t, &svm->devs, list) {
  53                 if (t->dev == dev) {
  54                         sdev = t;
  55                         break;
  56                 }
  57         }
  58         rcu_read_unlock();
  59
  60         return sdev;
  61 }
  62
  63 int intel_svm_enable_prq(struct intel_iommu *iommu)
  64 {
  65         struct iopf_queue *iopfq;
  66         struct page *pages;
  67         int irq, ret;
  68
  69         pages = alloc_pages_node(iommu->node, GFP_KERNEL | __GFP_ZERO, PRQ_ORDER);
  70         if (!pages) {
  71                 pr_warn("IOMMU: %s: Failed to allocate page request queue\n",
  72                         iommu->name);
  73                 return -ENOMEM;
  74         }
  75         iommu->prq = page_address(pages);
  76
  77         irq = dmar_alloc_hwirq(IOMMU_IRQ_ID_OFFSET_PRQ + iommu->seq_id, iommu->node, iommu);
  78         if (irq <= 0) {
  79                 pr_err("IOMMU: %s: Failed to create IRQ vector for page request queue\n",
  80                        iommu->name);
  81                 ret = -EINVAL;
  82                 goto free_prq;
  83         }
  84         iommu->pr_irq = irq;
  85
  86         snprintf(iommu->iopfq_name, sizeof(iommu->iopfq_name),
  87                  "dmar%d-iopfq", iommu->seq_id);
  88         iopfq = iopf_queue_alloc(iommu->iopfq_name);
  89         if (!iopfq) {
  90                 pr_err("IOMMU: %s: Failed to allocate iopf queue\n", iommu->name);
  91                 ret = -ENOMEM;
  92                 goto free_hwirq;
  93         }
  94         iommu->iopf_queue = iopfq;
  95
  96         snprintf(iommu->prq_name, sizeof(iommu->prq_name), "dmar%d-prq", iommu->seq_id);
  97
  98         ret = request_threaded_irq(irq, NULL, prq_event_thread, IRQF_ONESHOT,
  99                                    iommu->prq_name, iommu);
 100         if (ret) {
 101                 pr_err("IOMMU: %s: Failed to request IRQ for page request queue\n",
 102                        iommu->name);
 103                 goto free_iopfq;
 104         }
 105         dmar_writeq(iommu->reg + DMAR_PQH_REG, 0ULL);
 106         dmar_writeq(iommu->reg + DMAR_PQT_REG, 0ULL);
 107         dmar_writeq(iommu->reg + DMAR_PQA_REG, virt_to_phys(iommu->prq) | PRQ_ORDER);
 108
 109         init_completion(&iommu->prq_complete);
 110
 111         return 0;
 112
 113 free_iopfq:
 114         iopf_queue_free(iommu->iopf_queue);
 115         iommu->iopf_queue = NULL;
 116 free_hwirq:
 117         dmar_free_hwirq(irq);
 118         iommu->pr_irq = 0;
 119 free_prq:
 120         free_pages((unsigned long)iommu->prq, PRQ_ORDER);
 121         iommu->prq = NULL;
 122
 123         return ret;
 124 }
 125
 126 int intel_svm_finish_prq(struct intel_iommu *iommu)
 127 {
 128         dmar_writeq(iommu->reg + DMAR_PQH_REG, 0ULL);
 129         dmar_writeq(iommu->reg + DMAR_PQT_REG, 0ULL);
 130         dmar_writeq(iommu->reg + DMAR_PQA_REG, 0ULL);
 131
 132         if (iommu->pr_irq) {
 133                 free_irq(iommu->pr_irq, iommu);
 134                 dmar_free_hwirq(iommu->pr_irq);
 135                 iommu->pr_irq = 0;
 136         }
 137
 138         if (iommu->iopf_queue) {
 139                 iopf_queue_free(iommu->iopf_queue);
 140                 iommu->iopf_queue = NULL;
 141         }
 142
 143         free_pages((unsigned long)iommu->prq, PRQ_ORDER);
 144         iommu->prq = NULL;
 145
 146         return 0;
 147 }
 148
 149 void intel_svm_check(struct intel_iommu *iommu)
 150 {
 151         if (!pasid_supported(iommu))
 152                 return;
 153
 154         if (cpu_feature_enabled(X86_FEATURE_GBPAGES) &&
 155             !cap_fl1gp_support(iommu->cap)) {
 156                 pr_err("%s SVM disabled, incompatible 1GB page capability\n",
 157                        iommu->name);
 158                 return;
 159         }
 160
 161         if (cpu_feature_enabled(X86_FEATURE_LA57) &&
 162             !cap_fl5lp_support(iommu->cap)) {
 163                 pr_err("%s SVM disabled, incompatible paging mode\n",
 164                        iommu->name);
 165                 return;
 166         }
 167
 168         iommu->flags |= VTD_FLAG_SVM_CAPABLE;
 169 }
 170
 171 static void __flush_svm_range_dev(struct intel_svm *svm,
 172                                   struct intel_svm_dev *sdev,
 173                                   unsigned long address,
 174                                   unsigned long pages, int ih)
 175 {
 176         struct device_domain_info *info = dev_iommu_priv_get(sdev->dev);
 177
 178         if (WARN_ON(!pages))
 179                 return;
 180
 181         qi_flush_piotlb(sdev->iommu, sdev->did, svm->pasid, address, pages, ih);
 182         if (info->ats_enabled) {
 183                 qi_flush_dev_iotlb_pasid(sdev->iommu, sdev->sid, info->pfsid,
 184                                          svm->pasid, sdev->qdep, address,
 185                                          order_base_2(pages));
 186                 quirk_extra_dev_tlb_flush(info, address, order_base_2(pages),
 187                                           svm->pasid, sdev->qdep);
 188         }
 189 }
 190
 191 static void intel_flush_svm_range_dev(struct intel_svm *svm,
 192                                       struct intel_svm_dev *sdev,
 193                                       unsigned long address,
 194                                       unsigned long pages, int ih)
 195 {
 196         unsigned long shift = ilog2(__roundup_pow_of_two(pages));
 197         unsigned long align = (1ULL << (VTD_PAGE_SHIFT + shift));
 198         unsigned long start = ALIGN_DOWN(address, align);
 199         unsigned long end = ALIGN(address + (pages << VTD_PAGE_SHIFT), align);
 200
 201         while (start < end) {
 202                 __flush_svm_range_dev(svm, sdev, start, align >> VTD_PAGE_SHIFT, ih);
 203                 start += align;
 204         }
 205 }
 206
 207 static void intel_flush_svm_range(struct intel_svm *svm, unsigned long address,
 208                                 unsigned long pages, int ih)
 209 {
 210         struct intel_svm_dev *sdev;
 211
 212         rcu_read_lock();
 213         list_for_each_entry_rcu(sdev, &svm->devs, list)
 214                 intel_flush_svm_range_dev(svm, sdev, address, pages, ih);
 215         rcu_read_unlock();
 216 }
 217
 218 static void intel_flush_svm_all(struct intel_svm *svm)
 219 {
 220         struct device_domain_info *info;
 221         struct intel_svm_dev *sdev;
 222
 223         rcu_read_lock();
 224         list_for_each_entry_rcu(sdev, &svm->devs, list) {
 225                 info = dev_iommu_priv_get(sdev->dev);
 226
 227                 qi_flush_piotlb(sdev->iommu, sdev->did, svm->pasid, 0, -1UL, 0);
 228                 if (info->ats_enabled) {
 229                         qi_flush_dev_iotlb_pasid(sdev->iommu, sdev->sid, info->pfsid,
 230                                                  svm->pasid, sdev->qdep,
 231                                                  0, 64 - VTD_PAGE_SHIFT);
 232                         quirk_extra_dev_tlb_flush(info, 0, 64 - VTD_PAGE_SHIFT,
 233                                                   svm->pasid, sdev->qdep);
 234                 }
 235         }
 236         rcu_read_unlock();
 237 }
 238
 239 /* Pages have been freed at this point */
 240 static void intel_arch_invalidate_secondary_tlbs(struct mmu_notifier *mn,
 241                                         struct mm_struct *mm,
 242                                         unsigned long start, unsigned long end)
 243 {
 244         struct intel_svm *svm = container_of(mn, struct intel_svm, notifier);
 245
 246         if (start == 0 && end == -1UL) {
 247                 intel_flush_svm_all(svm);
 248                 return;
 249         }
 250
 251         intel_flush_svm_range(svm, start,
 252                               (end - start + PAGE_SIZE - 1) >> VTD_PAGE_SHIFT, 0);
 253 }
 254
 255 static void intel_mm_release(struct mmu_notifier *mn, struct mm_struct *mm)
 256 {
 257         struct intel_svm *svm = container_of(mn, struct intel_svm, notifier);
 258         struct intel_svm_dev *sdev;
 259
 260         /* This might end up being called from exit_mmap(), *before* the page
 261          * tables are cleared. And __mmu_notifier_release() will delete us from
 262          * the list of notifiers so that our invalidate_range() callback doesn't
 263          * get called when the page tables are cleared. So we need to protect
 264          * against hardware accessing those page tables.
 265          *
 266          * We do it by clearing the entry in the PASID table and then flushing
 267          * the IOTLB and the PASID table caches. This might upset hardware;
 268          * perhaps we'll want to point the PASID to a dummy PGD (like the zero
 269          * page) so that we end up taking a fault that the hardware really
 270          * *has* to handle gracefully without affecting other processes.
 271          */
 272         rcu_read_lock();
 273         list_for_each_entry_rcu(sdev, &svm->devs, list)
 274                 intel_pasid_tear_down_entry(sdev->iommu, sdev->dev,
 275                                             svm->pasid, true);
 276         rcu_read_unlock();
 277
 278 }
 279
 280 static const struct mmu_notifier_ops intel_mmuops = {
 281         .release = intel_mm_release,
 282         .arch_invalidate_secondary_tlbs = intel_arch_invalidate_secondary_tlbs,
 283 };
 284
 285 static int pasid_to_svm_sdev(struct device *dev, unsigned int pasid,
 286                              struct intel_svm **rsvm,
 287                              struct intel_svm_dev **rsdev)
 288 {
 289         struct intel_svm_dev *sdev = NULL;
 290         struct intel_svm *svm;
 291
 292         if (pasid == IOMMU_PASID_INVALID || pasid >= PASID_MAX)
 293                 return -EINVAL;
 294
 295         svm = pasid_private_find(pasid);
 296         if (IS_ERR(svm))
 297                 return PTR_ERR(svm);
 298
 299         if (!svm)
 300                 goto out;
 301
 302         /*
 303          * If we found svm for the PASID, there must be at least one device
 304          * bond.
 305          */
 306         if (WARN_ON(list_empty(&svm->devs)))
 307                 return -EINVAL;
 308         sdev = svm_lookup_device_by_dev(svm, dev);
 309
 310 out:
 311         *rsvm = svm;
 312         *rsdev = sdev;
 313
 314         return 0;
 315 }
 316
 317 static int intel_svm_set_dev_pasid(struct iommu_domain *domain,
 318                                    struct device *dev, ioasid_t pasid)
 319 {
 320         struct device_domain_info *info = dev_iommu_priv_get(dev);
 321         struct intel_iommu *iommu = info->iommu;
 322         struct mm_struct *mm = domain->mm;
 323         struct intel_svm_dev *sdev;
 324         struct intel_svm *svm;
 325         unsigned long sflags;
 326         int ret = 0;
 327
 328         svm = pasid_private_find(pasid);
 329         if (!svm) {
 330                 svm = kzalloc(sizeof(*svm), GFP_KERNEL);
 331                 if (!svm)
 332                         return -ENOMEM;
 333
 334                 svm->pasid = pasid;
 335                 svm->mm = mm;
 336                 INIT_LIST_HEAD_RCU(&svm->devs);
 337
 338                 svm->notifier.ops = &intel_mmuops;
 339                 ret = mmu_notifier_register(&svm->notifier, mm);
 340                 if (ret) {
 341                         kfree(svm);
 342                         return ret;
 343                 }
 344
 345                 ret = pasid_private_add(svm->pasid, svm);
 346                 if (ret) {
 347                         mmu_notifier_unregister(&svm->notifier, mm);
 348                         kfree(svm);
 349                         return ret;
 350                 }
 351         }
 352
 353         sdev = kzalloc(sizeof(*sdev), GFP_KERNEL);
 354         if (!sdev) {
 355                 ret = -ENOMEM;
 356                 goto free_svm;
 357         }
 358
 359         sdev->dev = dev;
 360         sdev->iommu = iommu;
 361         sdev->did = FLPT_DEFAULT_DID;
 362         sdev->sid = PCI_DEVID(info->bus, info->devfn);
 363         if (info->ats_enabled) {
 364                 sdev->qdep = info->ats_qdep;
 365                 if (sdev->qdep >= QI_DEV_EIOTLB_MAX_INVS)
 366                         sdev->qdep = 0;
 367         }
 368
 369         /* Setup the pasid table: */
 370         sflags = cpu_feature_enabled(X86_FEATURE_LA57) ? PASID_FLAG_FL5LP : 0;
 371         ret = intel_pasid_setup_first_level(iommu, dev, mm->pgd, pasid,
 372                                             FLPT_DEFAULT_DID, sflags);
 373         if (ret)
 374                 goto free_sdev;
 375
 376         list_add_rcu(&sdev->list, &svm->devs);
 377
 378         return 0;
 379
 380 free_sdev:
 381         kfree(sdev);
 382 free_svm:
 383         if (list_empty(&svm->devs)) {
 384                 mmu_notifier_unregister(&svm->notifier, mm);
 385                 pasid_private_remove(pasid);
 386                 kfree(svm);
 387         }
 388
 389         return ret;
 390 }
 391
 392 void intel_svm_remove_dev_pasid(struct device *dev, u32 pasid)
 393 {
 394         struct intel_svm_dev *sdev;
 395         struct intel_svm *svm;
 396         struct mm_struct *mm;
 397
 398         if (pasid_to_svm_sdev(dev, pasid, &svm, &sdev))
 399                 return;
 400         mm = svm->mm;
 401
 402         if (sdev) {
 403                 list_del_rcu(&sdev->list);
 404                 kfree_rcu(sdev, rcu);
 405
 406                 if (list_empty(&svm->devs)) {
 407                         if (svm->notifier.ops)
 408                                 mmu_notifier_unregister(&svm->notifier, mm);
 409                         pasid_private_remove(svm->pasid);
 410                         kfree(svm);
 411                 }
 412         }
 413 }
 414
 415 /* Page request queue descriptor */
 416 struct page_req_dsc {
 417         union {
 418                 struct {
 419                         u64 type:8;
 420                         u64 pasid_present:1;
 421                         u64 priv_data_present:1;
 422                         u64 rsvd:6;
 423                         u64 rid:16;
 424                         u64 pasid:20;
 425                         u64 exe_req:1;
 426                         u64 pm_req:1;
 427                         u64 rsvd2:10;
 428                 };
 429                 u64 qw_0;
 430         };
 431         union {
 432                 struct {
 433                         u64 rd_req:1;
 434                         u64 wr_req:1;
 435                         u64 lpig:1;
 436                         u64 prg_index:9;
 437                         u64 addr:52;
 438                 };
 439                 u64 qw_1;
 440         };
 441         u64 priv_data[2];
 442 };
 443
 444 static bool is_canonical_address(u64 addr)
 445 {
 446         int shift = 64 - (__VIRTUAL_MASK_SHIFT + 1);
 447         long saddr = (long) addr;
 448
 449         return (((saddr << shift) >> shift) == saddr);
 450 }
 451
 452 /**
 453  * intel_drain_pasid_prq - Drain page requests and responses for a pasid
 454  * @dev: target device
 455  * @pasid: pasid for draining
 456  *
 457  * Drain all pending page requests and responses related to @pasid in both
 458  * software and hardware. This is supposed to be called after the device
 459  * driver has stopped DMA, the pasid entry has been cleared, and both IOTLB
 460  * and DevTLB have been invalidated.
 461  *
 462  * It waits until all pending page requests for @pasid in the page fault
 463  * queue are completed by the prq handling thread. Then follow the steps
 464  * described in VT-d spec CH7.10 to drain all page requests and page
 465  * responses pending in the hardware.
 466  */
 467 void intel_drain_pasid_prq(struct device *dev, u32 pasid)
 468 {
 469         struct device_domain_info *info;
 470         struct dmar_domain *domain;
 471         struct intel_iommu *iommu;
 472         struct qi_desc desc[3];
 473         struct pci_dev *pdev;
 474         int head, tail;
 475         u16 sid, did;
 476         int qdep;
 477
 478         info = dev_iommu_priv_get(dev);
 479         if (WARN_ON(!info || !dev_is_pci(dev)))
 480                 return;
 481
 482         if (!info->pri_enabled)
 483                 return;
 484
 485         iommu = info->iommu;
 486         domain = info->domain;
 487         pdev = to_pci_dev(dev);
 488         sid = PCI_DEVID(info->bus, info->devfn);
 489         did = domain_id_iommu(domain, iommu);
 490         qdep = pci_ats_queue_depth(pdev);
 491
 492         /*
 493          * Check and wait until all pending page requests in the queue are
 494          * handled by the prq handling thread.
 495          */
 496 prq_retry:
 497         reinit_completion(&iommu->prq_complete);
 498         tail = dmar_readq(iommu->reg + DMAR_PQT_REG) & PRQ_RING_MASK;
 499         head = dmar_readq(iommu->reg + DMAR_PQH_REG) & PRQ_RING_MASK;
 500         while (head != tail) {
 501                 struct page_req_dsc *req;
 502
 503                 req = &iommu->prq[head / sizeof(*req)];
 504                 if (!req->pasid_present || req->pasid != pasid) {
 505                         head = (head + sizeof(*req)) & PRQ_RING_MASK;
 506                         continue;
 507                 }
 508
 509                 wait_for_completion(&iommu->prq_complete);
 510                 goto prq_retry;
 511         }
 512
 513         iopf_queue_flush_dev(dev);
 514
 515         /*
 516          * Perform steps described in VT-d spec CH7.10 to drain page
 517          * requests and responses in hardware.
 518          */
 519         memset(desc, 0, sizeof(desc));
 520         desc[0].qw0 = QI_IWD_STATUS_DATA(QI_DONE) |
 521                         QI_IWD_FENCE |
 522                         QI_IWD_TYPE;
 523         desc[1].qw0 = QI_EIOTLB_PASID(pasid) |
 524                         QI_EIOTLB_DID(did) |
 525                         QI_EIOTLB_GRAN(QI_GRAN_NONG_PASID) |
 526                         QI_EIOTLB_TYPE;
 527         desc[2].qw0 = QI_DEV_EIOTLB_PASID(pasid) |
 528                         QI_DEV_EIOTLB_SID(sid) |
 529                         QI_DEV_EIOTLB_QDEP(qdep) |
 530                         QI_DEIOTLB_TYPE |
 531                         QI_DEV_IOTLB_PFSID(info->pfsid);
 532 qi_retry:
 533         reinit_completion(&iommu->prq_complete);
 534         qi_submit_sync(iommu, desc, 3, QI_OPT_WAIT_DRAIN);
 535         if (readl(iommu->reg + DMAR_PRS_REG) & DMA_PRS_PRO) {
 536                 wait_for_completion(&iommu->prq_complete);
 537                 goto qi_retry;
 538         }
 539 }
 540
 541 static int prq_to_iommu_prot(struct page_req_dsc *req)
 542 {
 543         int prot = 0;
 544
 545         if (req->rd_req)
 546                 prot |= IOMMU_FAULT_PERM_READ;
 547         if (req->wr_req)
 548                 prot |= IOMMU_FAULT_PERM_WRITE;
 549         if (req->exe_req)
 550                 prot |= IOMMU_FAULT_PERM_EXEC;
 551         if (req->pm_req)
 552                 prot |= IOMMU_FAULT_PERM_PRIV;
 553
 554         return prot;
 555 }
 556
 557 static void intel_svm_prq_report(struct intel_iommu *iommu, struct device *dev,
 558                                  struct page_req_dsc *desc)
 559 {
 560         struct iopf_fault event = { };
 561
 562         /* Fill in event data for device specific processing */
 563         event.fault.type = IOMMU_FAULT_PAGE_REQ;
 564         event.fault.prm.addr = (u64)desc->addr << VTD_PAGE_SHIFT;
 565         event.fault.prm.pasid = desc->pasid;
 566         event.fault.prm.grpid = desc->prg_index;
 567         event.fault.prm.perm = prq_to_iommu_prot(desc);
 568
 569         if (desc->lpig)
 570                 event.fault.prm.flags |= IOMMU_FAULT_PAGE_REQUEST_LAST_PAGE;
 571         if (desc->pasid_present) {
 572                 event.fault.prm.flags |= IOMMU_FAULT_PAGE_REQUEST_PASID_VALID;
 573                 event.fault.prm.flags |= IOMMU_FAULT_PAGE_RESPONSE_NEEDS_PASID;
 574         }
 575         if (desc->priv_data_present) {
 576                 /*
 577                  * Set last page in group bit if private data is present,
 578                  * page response is required as it does for LPIG.
 579                  * iommu_report_device_fault() doesn't understand this vendor
 580                  * specific requirement thus we set last_page as a workaround.
 581                  */
 582                 event.fault.prm.flags |= IOMMU_FAULT_PAGE_REQUEST_LAST_PAGE;
 583                 event.fault.prm.flags |= IOMMU_FAULT_PAGE_REQUEST_PRIV_DATA;
 584                 event.fault.prm.private_data[0] = desc->priv_data[0];
 585                 event.fault.prm.private_data[1] = desc->priv_data[1];
 586         } else if (dmar_latency_enabled(iommu, DMAR_LATENCY_PRQ)) {
 587                 /*
 588                  * If the private data fields are not used by hardware, use it
 589                  * to monitor the prq handle latency.
 590                  */
 591                 event.fault.prm.private_data[0] = ktime_to_ns(ktime_get());
 592         }
 593
 594         iommu_report_device_fault(dev, &event);
 595 }
 596
 597 static void handle_bad_prq_event(struct intel_iommu *iommu,
 598                                  struct page_req_dsc *req, int result)
 599 {
 600         struct qi_desc desc;
 601
 602         pr_err("%s: Invalid page request: %08llx %08llx\n",
 603                iommu->name, ((unsigned long long *)req)[0],
 604                ((unsigned long long *)req)[1]);
 605
 606         /*
 607          * Per VT-d spec. v3.0 ch7.7, system software must
 608          * respond with page group response if private data
 609          * is present (PDP) or last page in group (LPIG) bit
 610          * is set. This is an additional VT-d feature beyond
 611          * PCI ATS spec.
 612          */
 613         if (!req->lpig && !req->priv_data_present)
 614                 return;
 615
 616         desc.qw0 = QI_PGRP_PASID(req->pasid) |
 617                         QI_PGRP_DID(req->rid) |
 618                         QI_PGRP_PASID_P(req->pasid_present) |
 619                         QI_PGRP_PDP(req->priv_data_present) |
 620                         QI_PGRP_RESP_CODE(result) |
 621                         QI_PGRP_RESP_TYPE;
 622         desc.qw1 = QI_PGRP_IDX(req->prg_index) |
 623                         QI_PGRP_LPIG(req->lpig);
 624
 625         if (req->priv_data_present) {
 626                 desc.qw2 = req->priv_data[0];
 627                 desc.qw3 = req->priv_data[1];
 628         } else {
 629                 desc.qw2 = 0;
 630                 desc.qw3 = 0;
 631         }
 632
 633         qi_submit_sync(iommu, &desc, 1, 0);
 634 }
 635
 636 static irqreturn_t prq_event_thread(int irq, void *d)
 637 {
 638         struct intel_iommu *iommu = d;
 639         struct page_req_dsc *req;
 640         int head, tail, handled;
 641         struct device *dev;
 642         u64 address;
 643
 644         /*
 645          * Clear PPR bit before reading head/tail registers, to ensure that
 646          * we get a new interrupt if needed.
 647          */
 648         writel(DMA_PRS_PPR, iommu->reg + DMAR_PRS_REG);
 649
 650         tail = dmar_readq(iommu->reg + DMAR_PQT_REG) & PRQ_RING_MASK;
 651         head = dmar_readq(iommu->reg + DMAR_PQH_REG) & PRQ_RING_MASK;
 652         handled = (head != tail);
 653         while (head != tail) {
 654                 req = &iommu->prq[head / sizeof(*req)];
 655                 address = (u64)req->addr << VTD_PAGE_SHIFT;
 656
 657                 if (unlikely(!req->pasid_present)) {
 658                         pr_err("IOMMU: %s: Page request without PASID\n",
 659                                iommu->name);
 660 bad_req:
 661                         handle_bad_prq_event(iommu, req, QI_RESP_INVALID);
 662                         goto prq_advance;
 663                 }
 664
 665                 if (unlikely(!is_canonical_address(address))) {
 666                         pr_err("IOMMU: %s: Address is not canonical\n",
 667                                iommu->name);
 668                         goto bad_req;
 669                 }
 670
 671                 if (unlikely(req->pm_req && (req->rd_req | req->wr_req))) {
 672                         pr_err("IOMMU: %s: Page request in Privilege Mode\n",
 673                                iommu->name);
 674                         goto bad_req;
 675                 }
 676
 677                 if (unlikely(req->exe_req && req->rd_req)) {
 678                         pr_err("IOMMU: %s: Execution request not supported\n",
 679                                iommu->name);
 680                         goto bad_req;
 681                 }
 682
 683                 /* Drop Stop Marker message. No need for a response. */
 684                 if (unlikely(req->lpig && !req->rd_req && !req->wr_req))
 685                         goto prq_advance;
 686
 687                 /*
 688                  * If prq is to be handled outside iommu driver via receiver of
 689                  * the fault notifiers, we skip the page response here.
 690                  */
 691                 mutex_lock(&iommu->iopf_lock);
 692                 dev = device_rbtree_find(iommu, req->rid);
 693                 if (!dev) {
 694                         mutex_unlock(&iommu->iopf_lock);
 695                         goto bad_req;
 696                 }
 697
 698                 intel_svm_prq_report(iommu, dev, req);
 699                 trace_prq_report(iommu, dev, req->qw_0, req->qw_1,
 700                                  req->priv_data[0], req->priv_data[1],
 701                                  iommu->prq_seq_number++);
 702                 mutex_unlock(&iommu->iopf_lock);
 703 prq_advance:
 704                 head = (head + sizeof(*req)) & PRQ_RING_MASK;
 705         }
 706
 707         dmar_writeq(iommu->reg + DMAR_PQH_REG, tail);
 708
 709         /*
 710          * Clear the page request overflow bit and wake up all threads that
 711          * are waiting for the completion of this handling.
 712          */
 713         if (readl(iommu->reg + DMAR_PRS_REG) & DMA_PRS_PRO) {
 714                 pr_info_ratelimited("IOMMU: %s: PRQ overflow detected\n",
 715                                     iommu->name);
 716                 head = dmar_readq(iommu->reg + DMAR_PQH_REG) & PRQ_RING_MASK;
 717                 tail = dmar_readq(iommu->reg + DMAR_PQT_REG) & PRQ_RING_MASK;
 718                 if (head == tail) {
 719                         iopf_queue_discard_partial(iommu->iopf_queue);
 720                         writel(DMA_PRS_PRO, iommu->reg + DMAR_PRS_REG);
 721                         pr_info_ratelimited("IOMMU: %s: PRQ overflow cleared",
 722                                             iommu->name);
 723                 }
 724         }
 725
 726         if (!completion_done(&iommu->prq_complete))
 727                 complete(&iommu->prq_complete);
 728
 729         return IRQ_RETVAL(handled);
 730 }
 731
 732 void intel_svm_page_response(struct device *dev, struct iopf_fault *evt,
 733                              struct iommu_page_response *msg)
 734 {
 735         struct device_domain_info *info = dev_iommu_priv_get(dev);
 736         struct intel_iommu *iommu = info->iommu;
 737         u8 bus = info->bus, devfn = info->devfn;
 738         struct iommu_fault_page_request *prm;
 739         bool private_present;
 740         bool pasid_present;
 741         bool last_page;
 742         u16 sid;
 743
 744         prm = &evt->fault.prm;
 745         sid = PCI_DEVID(bus, devfn);
 746         pasid_present = prm->flags & IOMMU_FAULT_PAGE_REQUEST_PASID_VALID;
 747         private_present = prm->flags & IOMMU_FAULT_PAGE_REQUEST_PRIV_DATA;
 748         last_page = prm->flags & IOMMU_FAULT_PAGE_REQUEST_LAST_PAGE;
 749
 750         /*
 751          * Per VT-d spec. v3.0 ch7.7, system software must respond
 752          * with page group response if private data is present (PDP)
 753          * or last page in group (LPIG) bit is set. This is an
 754          * additional VT-d requirement beyond PCI ATS spec.
 755          */
 756         if (last_page || private_present) {
 757                 struct qi_desc desc;
 758
 759                 desc.qw0 = QI_PGRP_PASID(prm->pasid) | QI_PGRP_DID(sid) |
 760                                 QI_PGRP_PASID_P(pasid_present) |
 761                                 QI_PGRP_PDP(private_present) |
 762                                 QI_PGRP_RESP_CODE(msg->code) |
 763                                 QI_PGRP_RESP_TYPE;
 764                 desc.qw1 = QI_PGRP_IDX(prm->grpid) | QI_PGRP_LPIG(last_page);
 765                 desc.qw2 = 0;
 766                 desc.qw3 = 0;
 767
 768                 if (private_present) {
 769                         desc.qw2 = prm->private_data[0];
 770                         desc.qw3 = prm->private_data[1];
 771                 } else if (prm->private_data[0]) {
 772                         dmar_latency_update(iommu, DMAR_LATENCY_PRQ,
 773                                 ktime_to_ns(ktime_get()) - prm->private_data[0]);
 774                 }
 775
 776                 qi_submit_sync(iommu, &desc, 1, 0);
 777         }
 778 }
 779
 780 static void intel_svm_domain_free(struct iommu_domain *domain)
 781 {
 782         kfree(to_dmar_domain(domain));
 783 }
 784
 785 static const struct iommu_domain_ops intel_svm_domain_ops = {
 786         .set_dev_pasid          = intel_svm_set_dev_pasid,
 787         .free                   = intel_svm_domain_free
 788 };
 789
 790 struct iommu_domain *intel_svm_domain_alloc(void)
 791 {
 792         struct dmar_domain *domain;
 793
 794         domain = kzalloc(sizeof(*domain), GFP_KERNEL);
 795         if (!domain)
 796                 return NULL;
 797         domain->domain.ops = &intel_svm_domain_ops;
 798
 799         return &domain->domain;
 800 }