drivers/iommu/amd_iommu_v2.c

   1 /*
   2  * Copyright (C) 2010-2012 Advanced Micro Devices, Inc.
   3  * Author: Joerg Roedel <jroedel@suse.de>
   4  *
   5  * This program is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 as published
   7  * by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the Free Software
  16  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  17  */
  18
  19 #include <linux/mmu_notifier.h>
  20 #include <linux/amd-iommu.h>
  21 #include <linux/mm_types.h>
  22 #include <linux/profile.h>
  23 #include <linux/module.h>
  24 #include <linux/sched.h>
  25 #include <linux/sched/mm.h>
  26 #include <linux/iommu.h>
  27 #include <linux/wait.h>
  28 #include <linux/pci.h>
  29 #include <linux/gfp.h>
  30
  31 #include "amd_iommu_types.h"
  32 #include "amd_iommu_proto.h"
  33
  34 MODULE_LICENSE("GPL v2");
  35 MODULE_AUTHOR("Joerg Roedel <jroedel@suse.de>");
  36
  37 #define MAX_DEVICES             0x10000
  38 #define PRI_QUEUE_SIZE          512
  39
  40 struct pri_queue {
  41         atomic_t inflight;
  42         bool finish;
  43         int status;
  44 };
  45
  46 struct pasid_state {
  47         struct list_head list;                  /* For global state-list */
  48         atomic_t count;                         /* Reference count */
  49         unsigned mmu_notifier_count;            /* Counting nested mmu_notifier
  50                                                    calls */
  51         struct mm_struct *mm;                   /* mm_struct for the faults */
  52         struct mmu_notifier mn;                 /* mmu_notifier handle */
  53         struct pri_queue pri[PRI_QUEUE_SIZE];   /* PRI tag states */
  54         struct device_state *device_state;      /* Link to our device_state */
  55         int pasid;                              /* PASID index */
  56         bool invalid;                           /* Used during setup and
  57                                                    teardown of the pasid */
  58         spinlock_t lock;                        /* Protect pri_queues and
  59                                                    mmu_notifer_count */
  60         wait_queue_head_t wq;                   /* To wait for count == 0 */
  61 };
  62
  63 struct device_state {
  64         struct list_head list;
  65         u16 devid;
  66         atomic_t count;
  67         struct pci_dev *pdev;
  68         struct pasid_state **states;
  69         struct iommu_domain *domain;
  70         int pasid_levels;
  71         int max_pasids;
  72         amd_iommu_invalid_ppr_cb inv_ppr_cb;
  73         amd_iommu_invalidate_ctx inv_ctx_cb;
  74         spinlock_t lock;
  75         wait_queue_head_t wq;
  76 };
  77
  78 struct fault {
  79         struct work_struct work;
  80         struct device_state *dev_state;
  81         struct pasid_state *state;
  82         struct mm_struct *mm;
  83         u64 address;
  84         u16 devid;
  85         u16 pasid;
  86         u16 tag;
  87         u16 finish;
  88         u16 flags;
  89 };
  90
  91 static LIST_HEAD(state_list);
  92 static spinlock_t state_lock;
  93
  94 static struct workqueue_struct *iommu_wq;
  95
  96 static void free_pasid_states(struct device_state *dev_state);
  97
  98 static u16 device_id(struct pci_dev *pdev)
  99 {
 100         u16 devid;
 101
 102         devid = pdev->bus->number;
 103         devid = (devid << 8) | pdev->devfn;
 104
 105         return devid;
 106 }
 107
 108 static struct device_state *__get_device_state(u16 devid)
 109 {
 110         struct device_state *dev_state;
 111
 112         list_for_each_entry(dev_state, &state_list, list) {
 113                 if (dev_state->devid == devid)
 114                         return dev_state;
 115         }
 116
 117         return NULL;
 118 }
 119
 120 static struct device_state *get_device_state(u16 devid)
 121 {
 122         struct device_state *dev_state;
 123         unsigned long flags;
 124
 125         spin_lock_irqsave(&state_lock, flags);
 126         dev_state = __get_device_state(devid);
 127         if (dev_state != NULL)
 128                 atomic_inc(&dev_state->count);
 129         spin_unlock_irqrestore(&state_lock, flags);
 130
 131         return dev_state;
 132 }
 133
 134 static void free_device_state(struct device_state *dev_state)
 135 {
 136         struct iommu_group *group;
 137
 138         /*
 139          * First detach device from domain - No more PRI requests will arrive
 140          * from that device after it is unbound from the IOMMUv2 domain.
 141          */
 142         group = iommu_group_get(&dev_state->pdev->dev);
 143         if (WARN_ON(!group))
 144                 return;
 145
 146         iommu_detach_group(dev_state->domain, group);
 147
 148         iommu_group_put(group);
 149
 150         /* Everything is down now, free the IOMMUv2 domain */
 151         iommu_domain_free(dev_state->domain);
 152
 153         /* Finally get rid of the device-state */
 154         kfree(dev_state);
 155 }
 156
 157 static void put_device_state(struct device_state *dev_state)
 158 {
 159         if (atomic_dec_and_test(&dev_state->count))
 160                 wake_up(&dev_state->wq);
 161 }
 162
 163 /* Must be called under dev_state->lock */
 164 static struct pasid_state **__get_pasid_state_ptr(struct device_state *dev_state,
 165                                                   int pasid, bool alloc)
 166 {
 167         struct pasid_state **root, **ptr;
 168         int level, index;
 169
 170         level = dev_state->pasid_levels;
 171         root  = dev_state->states;
 172
 173         while (true) {
 174
 175                 index = (pasid >> (9 * level)) & 0x1ff;
 176                 ptr   = &root[index];
 177
 178                 if (level == 0)
 179                         break;
 180
 181                 if (*ptr == NULL) {
 182                         if (!alloc)
 183                                 return NULL;
 184
 185                         *ptr = (void *)get_zeroed_page(GFP_ATOMIC);
 186                         if (*ptr == NULL)
 187                                 return NULL;
 188                 }
 189
 190                 root   = (struct pasid_state **)*ptr;
 191                 level -= 1;
 192         }
 193
 194         return ptr;
 195 }
 196
 197 static int set_pasid_state(struct device_state *dev_state,
 198                            struct pasid_state *pasid_state,
 199                            int pasid)
 200 {
 201         struct pasid_state **ptr;
 202         unsigned long flags;
 203         int ret;
 204
 205         spin_lock_irqsave(&dev_state->lock, flags);
 206         ptr = __get_pasid_state_ptr(dev_state, pasid, true);
 207
 208         ret = -ENOMEM;
 209         if (ptr == NULL)
 210                 goto out_unlock;
 211
 212         ret = -ENOMEM;
 213         if (*ptr != NULL)
 214                 goto out_unlock;
 215
 216         *ptr = pasid_state;
 217
 218         ret = 0;
 219
 220 out_unlock:
 221         spin_unlock_irqrestore(&dev_state->lock, flags);
 222
 223         return ret;
 224 }
 225
 226 static void clear_pasid_state(struct device_state *dev_state, int pasid)
 227 {
 228         struct pasid_state **ptr;
 229         unsigned long flags;
 230
 231         spin_lock_irqsave(&dev_state->lock, flags);
 232         ptr = __get_pasid_state_ptr(dev_state, pasid, true);
 233
 234         if (ptr == NULL)
 235                 goto out_unlock;
 236
 237         *ptr = NULL;
 238
 239 out_unlock:
 240         spin_unlock_irqrestore(&dev_state->lock, flags);
 241 }
 242
 243 static struct pasid_state *get_pasid_state(struct device_state *dev_state,
 244                                            int pasid)
 245 {
 246         struct pasid_state **ptr, *ret = NULL;
 247         unsigned long flags;
 248
 249         spin_lock_irqsave(&dev_state->lock, flags);
 250         ptr = __get_pasid_state_ptr(dev_state, pasid, false);
 251
 252         if (ptr == NULL)
 253                 goto out_unlock;
 254
 255         ret = *ptr;
 256         if (ret)
 257                 atomic_inc(&ret->count);
 258
 259 out_unlock:
 260         spin_unlock_irqrestore(&dev_state->lock, flags);
 261
 262         return ret;
 263 }
 264
 265 static void free_pasid_state(struct pasid_state *pasid_state)
 266 {
 267         kfree(pasid_state);
 268 }
 269
 270 static void put_pasid_state(struct pasid_state *pasid_state)
 271 {
 272         if (atomic_dec_and_test(&pasid_state->count))
 273                 wake_up(&pasid_state->wq);
 274 }
 275
 276 static void put_pasid_state_wait(struct pasid_state *pasid_state)
 277 {
 278         atomic_dec(&pasid_state->count);
 279         wait_event(pasid_state->wq, !atomic_read(&pasid_state->count));
 280         free_pasid_state(pasid_state);
 281 }
 282
 283 static void unbind_pasid(struct pasid_state *pasid_state)
 284 {
 285         struct iommu_domain *domain;
 286
 287         domain = pasid_state->device_state->domain;
 288
 289         /*
 290          * Mark pasid_state as invalid, no more faults will we added to the
 291          * work queue after this is visible everywhere.
 292          */
 293         pasid_state->invalid = true;
 294
 295         /* Make sure this is visible */
 296         smp_wmb();
 297
 298         /* After this the device/pasid can't access the mm anymore */
 299         amd_iommu_domain_clear_gcr3(domain, pasid_state->pasid);
 300
 301         /* Make sure no more pending faults are in the queue */
 302         flush_workqueue(iommu_wq);
 303 }
 304
 305 static void free_pasid_states_level1(struct pasid_state **tbl)
 306 {
 307         int i;
 308
 309         for (i = 0; i < 512; ++i) {
 310                 if (tbl[i] == NULL)
 311                         continue;
 312
 313                 free_page((unsigned long)tbl[i]);
 314         }
 315 }
 316
 317 static void free_pasid_states_level2(struct pasid_state **tbl)
 318 {
 319         struct pasid_state **ptr;
 320         int i;
 321
 322         for (i = 0; i < 512; ++i) {
 323                 if (tbl[i] == NULL)
 324                         continue;
 325
 326                 ptr = (struct pasid_state **)tbl[i];
 327                 free_pasid_states_level1(ptr);
 328         }
 329 }
 330
 331 static void free_pasid_states(struct device_state *dev_state)
 332 {
 333         struct pasid_state *pasid_state;
 334         int i;
 335
 336         for (i = 0; i < dev_state->max_pasids; ++i) {
 337                 pasid_state = get_pasid_state(dev_state, i);
 338                 if (pasid_state == NULL)
 339                         continue;
 340
 341                 put_pasid_state(pasid_state);
 342
 343                 /*
 344                  * This will call the mn_release function and
 345                  * unbind the PASID
 346                  */
 347                 mmu_notifier_unregister(&pasid_state->mn, pasid_state->mm);
 348
 349                 put_pasid_state_wait(pasid_state); /* Reference taken in
 350                                                       amd_iommu_bind_pasid */
 351
 352                 /* Drop reference taken in amd_iommu_bind_pasid */
 353                 put_device_state(dev_state);
 354         }
 355
 356         if (dev_state->pasid_levels == 2)
 357                 free_pasid_states_level2(dev_state->states);
 358         else if (dev_state->pasid_levels == 1)
 359                 free_pasid_states_level1(dev_state->states);
 360         else
 361                 BUG_ON(dev_state->pasid_levels != 0);
 362
 363         free_page((unsigned long)dev_state->states);
 364 }
 365
 366 static struct pasid_state *mn_to_state(struct mmu_notifier *mn)
 367 {
 368         return container_of(mn, struct pasid_state, mn);
 369 }
 370
 371 static void __mn_flush_page(struct mmu_notifier *mn,
 372                             unsigned long address)
 373 {
 374         struct pasid_state *pasid_state;
 375         struct device_state *dev_state;
 376
 377         pasid_state = mn_to_state(mn);
 378         dev_state   = pasid_state->device_state;
 379
 380         amd_iommu_flush_page(dev_state->domain, pasid_state->pasid, address);
 381 }
 382
 383 static int mn_clear_flush_young(struct mmu_notifier *mn,
 384                                 struct mm_struct *mm,
 385                                 unsigned long start,
 386                                 unsigned long end)
 387 {
 388         for (; start < end; start += PAGE_SIZE)
 389                 __mn_flush_page(mn, start);
 390
 391         return 0;
 392 }
 393
 394 static void mn_invalidate_range(struct mmu_notifier *mn,
 395                                 struct mm_struct *mm,
 396                                 unsigned long start, unsigned long end)
 397 {
 398         struct pasid_state *pasid_state;
 399         struct device_state *dev_state;
 400
 401         pasid_state = mn_to_state(mn);
 402         dev_state   = pasid_state->device_state;
 403
 404         if ((start ^ (end - 1)) < PAGE_SIZE)
 405                 amd_iommu_flush_page(dev_state->domain, pasid_state->pasid,
 406                                      start);
 407         else
 408                 amd_iommu_flush_tlb(dev_state->domain, pasid_state->pasid);
 409 }
 410
 411 static void mn_release(struct mmu_notifier *mn, struct mm_struct *mm)
 412 {
 413         struct pasid_state *pasid_state;
 414         struct device_state *dev_state;
 415         bool run_inv_ctx_cb;
 416
 417         might_sleep();
 418
 419         pasid_state    = mn_to_state(mn);
 420         dev_state      = pasid_state->device_state;
 421         run_inv_ctx_cb = !pasid_state->invalid;
 422
 423         if (run_inv_ctx_cb && dev_state->inv_ctx_cb)
 424                 dev_state->inv_ctx_cb(dev_state->pdev, pasid_state->pasid);
 425
 426         unbind_pasid(pasid_state);
 427 }
 428
 429 static const struct mmu_notifier_ops iommu_mn = {
 430         .flags                  = MMU_INVALIDATE_DOES_NOT_BLOCK,
 431         .release                = mn_release,
 432         .clear_flush_young      = mn_clear_flush_young,
 433         .invalidate_range       = mn_invalidate_range,
 434 };
 435
 436 static void set_pri_tag_status(struct pasid_state *pasid_state,
 437                                u16 tag, int status)
 438 {
 439         unsigned long flags;
 440
 441         spin_lock_irqsave(&pasid_state->lock, flags);
 442         pasid_state->pri[tag].status = status;
 443         spin_unlock_irqrestore(&pasid_state->lock, flags);
 444 }
 445
 446 static void finish_pri_tag(struct device_state *dev_state,
 447                            struct pasid_state *pasid_state,
 448                            u16 tag)
 449 {
 450         unsigned long flags;
 451
 452         spin_lock_irqsave(&pasid_state->lock, flags);
 453         if (atomic_dec_and_test(&pasid_state->pri[tag].inflight) &&
 454             pasid_state->pri[tag].finish) {
 455                 amd_iommu_complete_ppr(dev_state->pdev, pasid_state->pasid,
 456                                        pasid_state->pri[tag].status, tag);
 457                 pasid_state->pri[tag].finish = false;
 458                 pasid_state->pri[tag].status = PPR_SUCCESS;
 459         }
 460         spin_unlock_irqrestore(&pasid_state->lock, flags);
 461 }
 462
 463 static void handle_fault_error(struct fault *fault)
 464 {
 465         int status;
 466
 467         if (!fault->dev_state->inv_ppr_cb) {
 468                 set_pri_tag_status(fault->state, fault->tag, PPR_INVALID);
 469                 return;
 470         }
 471
 472         status = fault->dev_state->inv_ppr_cb(fault->dev_state->pdev,
 473                                               fault->pasid,
 474                                               fault->address,
 475                                               fault->flags);
 476         switch (status) {
 477         case AMD_IOMMU_INV_PRI_RSP_SUCCESS:
 478                 set_pri_tag_status(fault->state, fault->tag, PPR_SUCCESS);
 479                 break;
 480         case AMD_IOMMU_INV_PRI_RSP_INVALID:
 481                 set_pri_tag_status(fault->state, fault->tag, PPR_INVALID);
 482                 break;
 483         case AMD_IOMMU_INV_PRI_RSP_FAIL:
 484                 set_pri_tag_status(fault->state, fault->tag, PPR_FAILURE);
 485                 break;
 486         default:
 487                 BUG();
 488         }
 489 }
 490
 491 static bool access_error(struct vm_area_struct *vma, struct fault *fault)
 492 {
 493         unsigned long requested = 0;
 494
 495         if (fault->flags & PPR_FAULT_EXEC)
 496                 requested |= VM_EXEC;
 497
 498         if (fault->flags & PPR_FAULT_READ)
 499                 requested |= VM_READ;
 500
 501         if (fault->flags & PPR_FAULT_WRITE)
 502                 requested |= VM_WRITE;
 503
 504         return (requested & ~vma->vm_flags) != 0;
 505 }
 506
 507 static void do_fault(struct work_struct *work)
 508 {
 509         struct fault *fault = container_of(work, struct fault, work);
 510         struct vm_area_struct *vma;
 511         int ret = VM_FAULT_ERROR;
 512         unsigned int flags = 0;
 513         struct mm_struct *mm;
 514         u64 address;
 515
 516         mm = fault->state->mm;
 517         address = fault->address;
 518
 519         if (fault->flags & PPR_FAULT_USER)
 520                 flags |= FAULT_FLAG_USER;
 521         if (fault->flags & PPR_FAULT_WRITE)
 522                 flags |= FAULT_FLAG_WRITE;
 523         flags |= FAULT_FLAG_REMOTE;
 524
 525         down_read(&mm->mmap_sem);
 526         vma = find_extend_vma(mm, address);
 527         if (!vma || address < vma->vm_start)
 528                 /* failed to get a vma in the right range */
 529                 goto out;
 530
 531         /* Check if we have the right permissions on the vma */
 532         if (access_error(vma, fault))
 533                 goto out;
 534
 535         ret = handle_mm_fault(vma, address, flags);
 536 out:
 537         up_read(&mm->mmap_sem);
 538
 539         if (ret & VM_FAULT_ERROR)
 540                 /* failed to service fault */
 541                 handle_fault_error(fault);
 542
 543         finish_pri_tag(fault->dev_state, fault->state, fault->tag);
 544
 545         put_pasid_state(fault->state);
 546
 547         kfree(fault);
 548 }
 549
 550 static int ppr_notifier(struct notifier_block *nb, unsigned long e, void *data)
 551 {
 552         struct amd_iommu_fault *iommu_fault;
 553         struct pasid_state *pasid_state;
 554         struct device_state *dev_state;
 555         unsigned long flags;
 556         struct fault *fault;
 557         bool finish;
 558         u16 tag, devid;
 559         int ret;
 560         struct iommu_dev_data *dev_data;
 561         struct pci_dev *pdev = NULL;
 562
 563         iommu_fault = data;
 564         tag         = iommu_fault->tag & 0x1ff;
 565         finish      = (iommu_fault->tag >> 9) & 1;
 566
 567         devid = iommu_fault->device_id;
 568         pdev = pci_get_domain_bus_and_slot(0, PCI_BUS_NUM(devid),
 569                                            devid & 0xff);
 570         if (!pdev)
 571                 return -ENODEV;
 572         dev_data = get_dev_data(&pdev->dev);
 573
 574         /* In kdump kernel pci dev is not initialized yet -> send INVALID */
 575         ret = NOTIFY_DONE;
 576         if (translation_pre_enabled(amd_iommu_rlookup_table[devid])
 577                 && dev_data->defer_attach) {
 578                 amd_iommu_complete_ppr(pdev, iommu_fault->pasid,
 579                                        PPR_INVALID, tag);
 580                 goto out;
 581         }
 582
 583         dev_state = get_device_state(iommu_fault->device_id);
 584         if (dev_state == NULL)
 585                 goto out;
 586
 587         pasid_state = get_pasid_state(dev_state, iommu_fault->pasid);
 588         if (pasid_state == NULL || pasid_state->invalid) {
 589                 /* We know the device but not the PASID -> send INVALID */
 590                 amd_iommu_complete_ppr(dev_state->pdev, iommu_fault->pasid,
 591                                        PPR_INVALID, tag);
 592                 goto out_drop_state;
 593         }
 594
 595         spin_lock_irqsave(&pasid_state->lock, flags);
 596         atomic_inc(&pasid_state->pri[tag].inflight);
 597         if (finish)
 598                 pasid_state->pri[tag].finish = true;
 599         spin_unlock_irqrestore(&pasid_state->lock, flags);
 600
 601         fault = kzalloc(sizeof(*fault), GFP_ATOMIC);
 602         if (fault == NULL) {
 603                 /* We are OOM - send success and let the device re-fault */
 604                 finish_pri_tag(dev_state, pasid_state, tag);
 605                 goto out_drop_state;
 606         }
 607
 608         fault->dev_state = dev_state;
 609         fault->address   = iommu_fault->address;
 610         fault->state     = pasid_state;
 611         fault->tag       = tag;
 612         fault->finish    = finish;
 613         fault->pasid     = iommu_fault->pasid;
 614         fault->flags     = iommu_fault->flags;
 615         INIT_WORK(&fault->work, do_fault);
 616
 617         queue_work(iommu_wq, &fault->work);
 618
 619         ret = NOTIFY_OK;
 620
 621 out_drop_state:
 622
 623         if (ret != NOTIFY_OK && pasid_state)
 624                 put_pasid_state(pasid_state);
 625
 626         put_device_state(dev_state);
 627
 628 out:
 629         return ret;
 630 }
 631
 632 static struct notifier_block ppr_nb = {
 633         .notifier_call = ppr_notifier,
 634 };
 635
 636 int amd_iommu_bind_pasid(struct pci_dev *pdev, int pasid,
 637                          struct task_struct *task)
 638 {
 639         struct pasid_state *pasid_state;
 640         struct device_state *dev_state;
 641         struct mm_struct *mm;
 642         u16 devid;
 643         int ret;
 644
 645         might_sleep();
 646
 647         if (!amd_iommu_v2_supported())
 648                 return -ENODEV;
 649
 650         devid     = device_id(pdev);
 651         dev_state = get_device_state(devid);
 652
 653         if (dev_state == NULL)
 654                 return -EINVAL;
 655
 656         ret = -EINVAL;
 657         if (pasid < 0 || pasid >= dev_state->max_pasids)
 658                 goto out;
 659
 660         ret = -ENOMEM;
 661         pasid_state = kzalloc(sizeof(*pasid_state), GFP_KERNEL);
 662         if (pasid_state == NULL)
 663                 goto out;
 664
 665
 666         atomic_set(&pasid_state->count, 1);
 667         init_waitqueue_head(&pasid_state->wq);
 668         spin_lock_init(&pasid_state->lock);
 669
 670         mm                        = get_task_mm(task);
 671         pasid_state->mm           = mm;
 672         pasid_state->device_state = dev_state;
 673         pasid_state->pasid        = pasid;
 674         pasid_state->invalid      = true; /* Mark as valid only if we are
 675                                              done with setting up the pasid */
 676         pasid_state->mn.ops       = &iommu_mn;
 677
 678         if (pasid_state->mm == NULL)
 679                 goto out_free;
 680
 681         mmu_notifier_register(&pasid_state->mn, mm);
 682
 683         ret = set_pasid_state(dev_state, pasid_state, pasid);
 684         if (ret)
 685                 goto out_unregister;
 686
 687         ret = amd_iommu_domain_set_gcr3(dev_state->domain, pasid,
 688                                         __pa(pasid_state->mm->pgd));
 689         if (ret)
 690                 goto out_clear_state;
 691
 692         /* Now we are ready to handle faults */
 693         pasid_state->invalid = false;
 694
 695         /*
 696          * Drop the reference to the mm_struct here. We rely on the
 697          * mmu_notifier release call-back to inform us when the mm
 698          * is going away.
 699          */
 700         mmput(mm);
 701
 702         return 0;
 703
 704 out_clear_state:
 705         clear_pasid_state(dev_state, pasid);
 706
 707 out_unregister:
 708         mmu_notifier_unregister(&pasid_state->mn, mm);
 709         mmput(mm);
 710
 711 out_free:
 712         free_pasid_state(pasid_state);
 713
 714 out:
 715         put_device_state(dev_state);
 716
 717         return ret;
 718 }
 719 EXPORT_SYMBOL(amd_iommu_bind_pasid);
 720
 721 void amd_iommu_unbind_pasid(struct pci_dev *pdev, int pasid)
 722 {
 723         struct pasid_state *pasid_state;
 724         struct device_state *dev_state;
 725         u16 devid;
 726
 727         might_sleep();
 728
 729         if (!amd_iommu_v2_supported())
 730                 return;
 731
 732         devid = device_id(pdev);
 733         dev_state = get_device_state(devid);
 734         if (dev_state == NULL)
 735                 return;
 736
 737         if (pasid < 0 || pasid >= dev_state->max_pasids)
 738                 goto out;
 739
 740         pasid_state = get_pasid_state(dev_state, pasid);
 741         if (pasid_state == NULL)
 742                 goto out;
 743         /*
 744          * Drop reference taken here. We are safe because we still hold
 745          * the reference taken in the amd_iommu_bind_pasid function.
 746          */
 747         put_pasid_state(pasid_state);
 748
 749         /* Clear the pasid state so that the pasid can be re-used */
 750         clear_pasid_state(dev_state, pasid_state->pasid);
 751
 752         /*
 753          * Call mmu_notifier_unregister to drop our reference
 754          * to pasid_state->mm
 755          */
 756         mmu_notifier_unregister(&pasid_state->mn, pasid_state->mm);
 757
 758         put_pasid_state_wait(pasid_state); /* Reference taken in
 759                                               amd_iommu_bind_pasid */
 760 out:
 761         /* Drop reference taken in this function */
 762         put_device_state(dev_state);
 763
 764         /* Drop reference taken in amd_iommu_bind_pasid */
 765         put_device_state(dev_state);
 766 }
 767 EXPORT_SYMBOL(amd_iommu_unbind_pasid);
 768
 769 int amd_iommu_init_device(struct pci_dev *pdev, int pasids)
 770 {
 771         struct device_state *dev_state;
 772         struct iommu_group *group;
 773         unsigned long flags;
 774         int ret, tmp;
 775         u16 devid;
 776
 777         might_sleep();
 778
 779         if (!amd_iommu_v2_supported())
 780                 return -ENODEV;
 781
 782         if (pasids <= 0 || pasids > (PASID_MASK + 1))
 783                 return -EINVAL;
 784
 785         devid = device_id(pdev);
 786
 787         dev_state = kzalloc(sizeof(*dev_state), GFP_KERNEL);
 788         if (dev_state == NULL)
 789                 return -ENOMEM;
 790
 791         spin_lock_init(&dev_state->lock);
 792         init_waitqueue_head(&dev_state->wq);
 793         dev_state->pdev  = pdev;
 794         dev_state->devid = devid;
 795
 796         tmp = pasids;
 797         for (dev_state->pasid_levels = 0; (tmp - 1) & ~0x1ff; tmp >>= 9)
 798                 dev_state->pasid_levels += 1;
 799
 800         atomic_set(&dev_state->count, 1);
 801         dev_state->max_pasids = pasids;
 802
 803         ret = -ENOMEM;
 804         dev_state->states = (void *)get_zeroed_page(GFP_KERNEL);
 805         if (dev_state->states == NULL)
 806                 goto out_free_dev_state;
 807
 808         dev_state->domain = iommu_domain_alloc(&pci_bus_type);
 809         if (dev_state->domain == NULL)
 810                 goto out_free_states;
 811
 812         amd_iommu_domain_direct_map(dev_state->domain);
 813
 814         ret = amd_iommu_domain_enable_v2(dev_state->domain, pasids);
 815         if (ret)
 816                 goto out_free_domain;
 817
 818         group = iommu_group_get(&pdev->dev);
 819         if (!group) {
 820                 ret = -EINVAL;
 821                 goto out_free_domain;
 822         }
 823
 824         ret = iommu_attach_group(dev_state->domain, group);
 825         if (ret != 0)
 826                 goto out_drop_group;
 827
 828         iommu_group_put(group);
 829
 830         spin_lock_irqsave(&state_lock, flags);
 831
 832         if (__get_device_state(devid) != NULL) {
 833                 spin_unlock_irqrestore(&state_lock, flags);
 834                 ret = -EBUSY;
 835                 goto out_free_domain;
 836         }
 837
 838         list_add_tail(&dev_state->list, &state_list);
 839
 840         spin_unlock_irqrestore(&state_lock, flags);
 841
 842         return 0;
 843
 844 out_drop_group:
 845         iommu_group_put(group);
 846
 847 out_free_domain:
 848         iommu_domain_free(dev_state->domain);
 849
 850 out_free_states:
 851         free_page((unsigned long)dev_state->states);
 852
 853 out_free_dev_state:
 854         kfree(dev_state);
 855
 856         return ret;
 857 }
 858 EXPORT_SYMBOL(amd_iommu_init_device);
 859
 860 void amd_iommu_free_device(struct pci_dev *pdev)
 861 {
 862         struct device_state *dev_state;
 863         unsigned long flags;
 864         u16 devid;
 865
 866         if (!amd_iommu_v2_supported())
 867                 return;
 868
 869         devid = device_id(pdev);
 870
 871         spin_lock_irqsave(&state_lock, flags);
 872
 873         dev_state = __get_device_state(devid);
 874         if (dev_state == NULL) {
 875                 spin_unlock_irqrestore(&state_lock, flags);
 876                 return;
 877         }
 878
 879         list_del(&dev_state->list);
 880
 881         spin_unlock_irqrestore(&state_lock, flags);
 882
 883         /* Get rid of any remaining pasid states */
 884         free_pasid_states(dev_state);
 885
 886         put_device_state(dev_state);
 887         /*
 888          * Wait until the last reference is dropped before freeing
 889          * the device state.
 890          */
 891         wait_event(dev_state->wq, !atomic_read(&dev_state->count));
 892         free_device_state(dev_state);
 893 }
 894 EXPORT_SYMBOL(amd_iommu_free_device);
 895
 896 int amd_iommu_set_invalid_ppr_cb(struct pci_dev *pdev,
 897                                  amd_iommu_invalid_ppr_cb cb)
 898 {
 899         struct device_state *dev_state;
 900         unsigned long flags;
 901         u16 devid;
 902         int ret;
 903
 904         if (!amd_iommu_v2_supported())
 905                 return -ENODEV;
 906
 907         devid = device_id(pdev);
 908
 909         spin_lock_irqsave(&state_lock, flags);
 910
 911         ret = -EINVAL;
 912         dev_state = __get_device_state(devid);
 913         if (dev_state == NULL)
 914                 goto out_unlock;
 915
 916         dev_state->inv_ppr_cb = cb;
 917
 918         ret = 0;
 919
 920 out_unlock:
 921         spin_unlock_irqrestore(&state_lock, flags);
 922
 923         return ret;
 924 }
 925 EXPORT_SYMBOL(amd_iommu_set_invalid_ppr_cb);
 926
 927 int amd_iommu_set_invalidate_ctx_cb(struct pci_dev *pdev,
 928                                     amd_iommu_invalidate_ctx cb)
 929 {
 930         struct device_state *dev_state;
 931         unsigned long flags;
 932         u16 devid;
 933         int ret;
 934
 935         if (!amd_iommu_v2_supported())
 936                 return -ENODEV;
 937
 938         devid = device_id(pdev);
 939
 940         spin_lock_irqsave(&state_lock, flags);
 941
 942         ret = -EINVAL;
 943         dev_state = __get_device_state(devid);
 944         if (dev_state == NULL)
 945                 goto out_unlock;
 946
 947         dev_state->inv_ctx_cb = cb;
 948
 949         ret = 0;
 950
 951 out_unlock:
 952         spin_unlock_irqrestore(&state_lock, flags);
 953
 954         return ret;
 955 }
 956 EXPORT_SYMBOL(amd_iommu_set_invalidate_ctx_cb);
 957
 958 static int __init amd_iommu_v2_init(void)
 959 {
 960         int ret;
 961
 962         pr_info("AMD IOMMUv2 driver by Joerg Roedel <jroedel@suse.de>\n");
 963
 964         if (!amd_iommu_v2_supported()) {
 965                 pr_info("AMD IOMMUv2 functionality not available on this system\n");
 966                 /*
 967                  * Load anyway to provide the symbols to other modules
 968                  * which may use AMD IOMMUv2 optionally.
 969                  */
 970                 return 0;
 971         }
 972
 973         spin_lock_init(&state_lock);
 974
 975         ret = -ENOMEM;
 976         iommu_wq = alloc_workqueue("amd_iommu_v2", WQ_MEM_RECLAIM, 0);
 977         if (iommu_wq == NULL)
 978                 goto out;
 979
 980         amd_iommu_register_ppr_notifier(&ppr_nb);
 981
 982         return 0;
 983
 984 out:
 985         return ret;
 986 }
 987
 988 static void __exit amd_iommu_v2_exit(void)
 989 {
 990         struct device_state *dev_state;
 991         int i;
 992
 993         if (!amd_iommu_v2_supported())
 994                 return;
 995
 996         amd_iommu_unregister_ppr_notifier(&ppr_nb);
 997
 998         flush_workqueue(iommu_wq);
 999
1000         /*
1001          * The loop below might call flush_workqueue(), so call
1002          * destroy_workqueue() after it
1003          */
1004         for (i = 0; i < MAX_DEVICES; ++i) {
1005                 dev_state = get_device_state(i);
1006
1007                 if (dev_state == NULL)
1008                         continue;
1009
1010                 WARN_ON_ONCE(1);
1011
1012                 put_device_state(dev_state);
1013                 amd_iommu_free_device(dev_state->pdev);
1014         }
1015
1016         destroy_workqueue(iommu_wq);
1017 }
1018
1019 module_init(amd_iommu_v2_init);
1020 module_exit(amd_iommu_v2_exit);