drivers/gpu/drm/nouveau/nouveau_svm.c

   1 /*
   2  * Copyright 2018 Red Hat Inc.
   3  *
   4  * Permission is hereby granted, free of charge, to any person obtaining a
   5  * copy of this software and associated documentation files (the "Software"),
   6  * to deal in the Software without restriction, including without limitation
   7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   8  * and/or sell copies of the Software, and to permit persons to whom the
   9  * Software is furnished to do so, subject to the following conditions:
  10  *
  11  * The above copyright notice and this permission notice shall be included in
  12  * all copies or substantial portions of the Software.
  13  *
  14  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  15  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  17  * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
  18  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
  19  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
  20  * OTHER DEALINGS IN THE SOFTWARE.
  21  */
  22 #include "nouveau_svm.h"
  23 #include "nouveau_drv.h"
  24 #include "nouveau_chan.h"
  25 #include "nouveau_dmem.h"
  26
  27 #include <nvif/notify.h>
  28 #include <nvif/object.h>
  29 #include <nvif/vmm.h>
  30
  31 #include <nvif/class.h>
  32 #include <nvif/clb069.h>
  33 #include <nvif/ifc00d.h>
  34
  35 #include <linux/sched/mm.h>
  36 #include <linux/sort.h>
  37 #include <linux/hmm.h>
  38
  39 struct nouveau_svm {
  40         struct nouveau_drm *drm;
  41         struct mutex mutex;
  42         struct list_head inst;
  43
  44         struct nouveau_svm_fault_buffer {
  45                 int id;
  46                 struct nvif_object object;
  47                 u32 entries;
  48                 u32 getaddr;
  49                 u32 putaddr;
  50                 u32 get;
  51                 u32 put;
  52                 struct nvif_notify notify;
  53
  54                 struct nouveau_svm_fault {
  55                         u64 inst;
  56                         u64 addr;
  57                         u64 time;
  58                         u32 engine;
  59                         u8  gpc;
  60                         u8  hub;
  61                         u8  access;
  62                         u8  client;
  63                         u8  fault;
  64                         struct nouveau_svmm *svmm;
  65                 } **fault;
  66                 int fault_nr;
  67         } buffer[1];
  68 };
  69
  70 #define SVM_DBG(s,f,a...) NV_DEBUG((s)->drm, "svm: "f"\n", ##a)
  71 #define SVM_ERR(s,f,a...) NV_WARN((s)->drm, "svm: "f"\n", ##a)
  72
  73 struct nouveau_pfnmap_args {
  74         struct nvif_ioctl_v0 i;
  75         struct nvif_ioctl_mthd_v0 m;
  76         struct nvif_vmm_pfnmap_v0 p;
  77 };
  78
  79 struct nouveau_ivmm {
  80         struct nouveau_svmm *svmm;
  81         u64 inst;
  82         struct list_head head;
  83 };
  84
  85 static struct nouveau_ivmm *
  86 nouveau_ivmm_find(struct nouveau_svm *svm, u64 inst)
  87 {
  88         struct nouveau_ivmm *ivmm;
  89         list_for_each_entry(ivmm, &svm->inst, head) {
  90                 if (ivmm->inst == inst)
  91                         return ivmm;
  92         }
  93         return NULL;
  94 }
  95
  96 #define SVMM_DBG(s,f,a...)                                                     \
  97         NV_DEBUG((s)->vmm->cli->drm, "svm-%p: "f"\n", (s), ##a)
  98 #define SVMM_ERR(s,f,a...)                                                     \
  99         NV_WARN((s)->vmm->cli->drm, "svm-%p: "f"\n", (s), ##a)
 100
 101 int
 102 nouveau_svmm_bind(struct drm_device *dev, void *data,
 103                   struct drm_file *file_priv)
 104 {
 105         struct nouveau_cli *cli = nouveau_cli(file_priv);
 106         struct drm_nouveau_svm_bind *args = data;
 107         unsigned target, cmd, priority;
 108         unsigned long addr, end;
 109         struct mm_struct *mm;
 110
 111         args->va_start &= PAGE_MASK;
 112         args->va_end = ALIGN(args->va_end, PAGE_SIZE);
 113
 114         /* Sanity check arguments */
 115         if (args->reserved0 || args->reserved1)
 116                 return -EINVAL;
 117         if (args->header & (~NOUVEAU_SVM_BIND_VALID_MASK))
 118                 return -EINVAL;
 119         if (args->va_start >= args->va_end)
 120                 return -EINVAL;
 121
 122         cmd = args->header >> NOUVEAU_SVM_BIND_COMMAND_SHIFT;
 123         cmd &= NOUVEAU_SVM_BIND_COMMAND_MASK;
 124         switch (cmd) {
 125         case NOUVEAU_SVM_BIND_COMMAND__MIGRATE:
 126                 break;
 127         default:
 128                 return -EINVAL;
 129         }
 130
 131         priority = args->header >> NOUVEAU_SVM_BIND_PRIORITY_SHIFT;
 132         priority &= NOUVEAU_SVM_BIND_PRIORITY_MASK;
 133
 134         /* FIXME support CPU target ie all target value < GPU_VRAM */
 135         target = args->header >> NOUVEAU_SVM_BIND_TARGET_SHIFT;
 136         target &= NOUVEAU_SVM_BIND_TARGET_MASK;
 137         switch (target) {
 138         case NOUVEAU_SVM_BIND_TARGET__GPU_VRAM:
 139                 break;
 140         default:
 141                 return -EINVAL;
 142         }
 143
 144         /*
 145          * FIXME: For now refuse non 0 stride, we need to change the migrate
 146          * kernel function to handle stride to avoid to create a mess within
 147          * each device driver.
 148          */
 149         if (args->stride)
 150                 return -EINVAL;
 151
 152         /*
 153          * Ok we are ask to do something sane, for now we only support migrate
 154          * commands but we will add things like memory policy (what to do on
 155          * page fault) and maybe some other commands.
 156          */
 157
 158         mm = get_task_mm(current);
 159         mmap_read_lock(mm);
 160
 161         if (!cli->svm.svmm) {
 162                 mmap_read_unlock(mm);
 163                 return -EINVAL;
 164         }
 165
 166         for (addr = args->va_start, end = args->va_end; addr < end;) {
 167                 struct vm_area_struct *vma;
 168                 unsigned long next;
 169
 170                 vma = find_vma_intersection(mm, addr, end);
 171                 if (!vma)
 172                         break;
 173
 174                 addr = max(addr, vma->vm_start);
 175                 next = min(vma->vm_end, end);
 176                 /* This is a best effort so we ignore errors */
 177                 nouveau_dmem_migrate_vma(cli->drm, cli->svm.svmm, vma, addr,
 178                                          next);
 179                 addr = next;
 180         }
 181
 182         /*
 183          * FIXME Return the number of page we have migrated, again we need to
 184          * update the migrate API to return that information so that we can
 185          * report it to user space.
 186          */
 187         args->result = 0;
 188
 189         mmap_read_unlock(mm);
 190         mmput(mm);
 191
 192         return 0;
 193 }
 194
 195 /* Unlink channel instance from SVMM. */
 196 void
 197 nouveau_svmm_part(struct nouveau_svmm *svmm, u64 inst)
 198 {
 199         struct nouveau_ivmm *ivmm;
 200         if (svmm) {
 201                 mutex_lock(&svmm->vmm->cli->drm->svm->mutex);
 202                 ivmm = nouveau_ivmm_find(svmm->vmm->cli->drm->svm, inst);
 203                 if (ivmm) {
 204                         list_del(&ivmm->head);
 205                         kfree(ivmm);
 206                 }
 207                 mutex_unlock(&svmm->vmm->cli->drm->svm->mutex);
 208         }
 209 }
 210
 211 /* Link channel instance to SVMM. */
 212 int
 213 nouveau_svmm_join(struct nouveau_svmm *svmm, u64 inst)
 214 {
 215         struct nouveau_ivmm *ivmm;
 216         if (svmm) {
 217                 if (!(ivmm = kmalloc(sizeof(*ivmm), GFP_KERNEL)))
 218                         return -ENOMEM;
 219                 ivmm->svmm = svmm;
 220                 ivmm->inst = inst;
 221
 222                 mutex_lock(&svmm->vmm->cli->drm->svm->mutex);
 223                 list_add(&ivmm->head, &svmm->vmm->cli->drm->svm->inst);
 224                 mutex_unlock(&svmm->vmm->cli->drm->svm->mutex);
 225         }
 226         return 0;
 227 }
 228
 229 /* Invalidate SVMM address-range on GPU. */
 230 void
 231 nouveau_svmm_invalidate(struct nouveau_svmm *svmm, u64 start, u64 limit)
 232 {
 233         if (limit > start) {
 234                 bool super = svmm->vmm->vmm.object.client->super;
 235                 svmm->vmm->vmm.object.client->super = true;
 236                 nvif_object_mthd(&svmm->vmm->vmm.object, NVIF_VMM_V0_PFNCLR,
 237                                  &(struct nvif_vmm_pfnclr_v0) {
 238                                         .addr = start,
 239                                         .size = limit - start,
 240                                  }, sizeof(struct nvif_vmm_pfnclr_v0));
 241                 svmm->vmm->vmm.object.client->super = super;
 242         }
 243 }
 244
 245 static int
 246 nouveau_svmm_invalidate_range_start(struct mmu_notifier *mn,
 247                                     const struct mmu_notifier_range *update)
 248 {
 249         struct nouveau_svmm *svmm =
 250                 container_of(mn, struct nouveau_svmm, notifier);
 251         unsigned long start = update->start;
 252         unsigned long limit = update->end;
 253
 254         if (!mmu_notifier_range_blockable(update))
 255                 return -EAGAIN;
 256
 257         SVMM_DBG(svmm, "invalidate %016lx-%016lx", start, limit);
 258
 259         mutex_lock(&svmm->mutex);
 260         if (unlikely(!svmm->vmm))
 261                 goto out;
 262
 263         /*
 264          * Ignore invalidation callbacks for device private pages since
 265          * the invalidation is handled as part of the migration process.
 266          */
 267         if (update->event == MMU_NOTIFY_MIGRATE &&
 268             update->migrate_pgmap_owner == svmm->vmm->cli->drm->dev)
 269                 goto out;
 270
 271         if (limit > svmm->unmanaged.start && start < svmm->unmanaged.limit) {
 272                 if (start < svmm->unmanaged.start) {
 273                         nouveau_svmm_invalidate(svmm, start,
 274                                                 svmm->unmanaged.limit);
 275                 }
 276                 start = svmm->unmanaged.limit;
 277         }
 278
 279         nouveau_svmm_invalidate(svmm, start, limit);
 280
 281 out:
 282         mutex_unlock(&svmm->mutex);
 283         return 0;
 284 }
 285
 286 static void nouveau_svmm_free_notifier(struct mmu_notifier *mn)
 287 {
 288         kfree(container_of(mn, struct nouveau_svmm, notifier));
 289 }
 290
 291 static const struct mmu_notifier_ops nouveau_mn_ops = {
 292         .invalidate_range_start = nouveau_svmm_invalidate_range_start,
 293         .free_notifier = nouveau_svmm_free_notifier,
 294 };
 295
 296 void
 297 nouveau_svmm_fini(struct nouveau_svmm **psvmm)
 298 {
 299         struct nouveau_svmm *svmm = *psvmm;
 300         if (svmm) {
 301                 mutex_lock(&svmm->mutex);
 302                 svmm->vmm = NULL;
 303                 mutex_unlock(&svmm->mutex);
 304                 mmu_notifier_put(&svmm->notifier);
 305                 *psvmm = NULL;
 306         }
 307 }
 308
 309 int
 310 nouveau_svmm_init(struct drm_device *dev, void *data,
 311                   struct drm_file *file_priv)
 312 {
 313         struct nouveau_cli *cli = nouveau_cli(file_priv);
 314         struct nouveau_svmm *svmm;
 315         struct drm_nouveau_svm_init *args = data;
 316         int ret;
 317
 318         /* Allocate tracking for SVM-enabled VMM. */
 319         if (!(svmm = kzalloc(sizeof(*svmm), GFP_KERNEL)))
 320                 return -ENOMEM;
 321         svmm->vmm = &cli->svm;
 322         svmm->unmanaged.start = args->unmanaged_addr;
 323         svmm->unmanaged.limit = args->unmanaged_addr + args->unmanaged_size;
 324         mutex_init(&svmm->mutex);
 325
 326         /* Check that SVM isn't already enabled for the client. */
 327         mutex_lock(&cli->mutex);
 328         if (cli->svm.cli) {
 329                 ret = -EBUSY;
 330                 goto out_free;
 331         }
 332
 333         /* Allocate a new GPU VMM that can support SVM (managed by the
 334          * client, with replayable faults enabled).
 335          *
 336          * All future channel/memory allocations will make use of this
 337          * VMM instead of the standard one.
 338          */
 339         ret = nvif_vmm_ctor(&cli->mmu, "svmVmm",
 340                             cli->vmm.vmm.object.oclass, true,
 341                             args->unmanaged_addr, args->unmanaged_size,
 342                             &(struct gp100_vmm_v0) {
 343                                 .fault_replay = true,
 344                             }, sizeof(struct gp100_vmm_v0), &cli->svm.vmm);
 345         if (ret)
 346                 goto out_free;
 347
 348         mmap_write_lock(current->mm);
 349         svmm->notifier.ops = &nouveau_mn_ops;
 350         ret = __mmu_notifier_register(&svmm->notifier, current->mm);
 351         if (ret)
 352                 goto out_mm_unlock;
 353         /* Note, ownership of svmm transfers to mmu_notifier */
 354
 355         cli->svm.svmm = svmm;
 356         cli->svm.cli = cli;
 357         mmap_write_unlock(current->mm);
 358         mutex_unlock(&cli->mutex);
 359         return 0;
 360
 361 out_mm_unlock:
 362         mmap_write_unlock(current->mm);
 363 out_free:
 364         mutex_unlock(&cli->mutex);
 365         kfree(svmm);
 366         return ret;
 367 }
 368
 369 /* Issue fault replay for GPU to retry accesses that faulted previously. */
 370 static void
 371 nouveau_svm_fault_replay(struct nouveau_svm *svm)
 372 {
 373         SVM_DBG(svm, "replay");
 374         WARN_ON(nvif_object_mthd(&svm->drm->client.vmm.vmm.object,
 375                                  GP100_VMM_VN_FAULT_REPLAY,
 376                                  &(struct gp100_vmm_fault_replay_vn) {},
 377                                  sizeof(struct gp100_vmm_fault_replay_vn)));
 378 }
 379
 380 /* Cancel a replayable fault that could not be handled.
 381  *
 382  * Cancelling the fault will trigger recovery to reset the engine
 383  * and kill the offending channel (ie. GPU SIGSEGV).
 384  */
 385 static void
 386 nouveau_svm_fault_cancel(struct nouveau_svm *svm,
 387                          u64 inst, u8 hub, u8 gpc, u8 client)
 388 {
 389         SVM_DBG(svm, "cancel %016llx %d %02x %02x", inst, hub, gpc, client);
 390         WARN_ON(nvif_object_mthd(&svm->drm->client.vmm.vmm.object,
 391                                  GP100_VMM_VN_FAULT_CANCEL,
 392                                  &(struct gp100_vmm_fault_cancel_v0) {
 393                                         .hub = hub,
 394                                         .gpc = gpc,
 395                                         .client = client,
 396                                         .inst = inst,
 397                                  }, sizeof(struct gp100_vmm_fault_cancel_v0)));
 398 }
 399
 400 static void
 401 nouveau_svm_fault_cancel_fault(struct nouveau_svm *svm,
 402                                struct nouveau_svm_fault *fault)
 403 {
 404         nouveau_svm_fault_cancel(svm, fault->inst,
 405                                       fault->hub,
 406                                       fault->gpc,
 407                                       fault->client);
 408 }
 409
 410 static int
 411 nouveau_svm_fault_cmp(const void *a, const void *b)
 412 {
 413         const struct nouveau_svm_fault *fa = *(struct nouveau_svm_fault **)a;
 414         const struct nouveau_svm_fault *fb = *(struct nouveau_svm_fault **)b;
 415         int ret;
 416         if ((ret = (s64)fa->inst - fb->inst))
 417                 return ret;
 418         if ((ret = (s64)fa->addr - fb->addr))
 419                 return ret;
 420         /*XXX: atomic? */
 421         return (fa->access == 0 || fa->access == 3) -
 422                (fb->access == 0 || fb->access == 3);
 423 }
 424
 425 static void
 426 nouveau_svm_fault_cache(struct nouveau_svm *svm,
 427                         struct nouveau_svm_fault_buffer *buffer, u32 offset)
 428 {
 429         struct nvif_object *memory = &buffer->object;
 430         const u32 instlo = nvif_rd32(memory, offset + 0x00);
 431         const u32 insthi = nvif_rd32(memory, offset + 0x04);
 432         const u32 addrlo = nvif_rd32(memory, offset + 0x08);
 433         const u32 addrhi = nvif_rd32(memory, offset + 0x0c);
 434         const u32 timelo = nvif_rd32(memory, offset + 0x10);
 435         const u32 timehi = nvif_rd32(memory, offset + 0x14);
 436         const u32 engine = nvif_rd32(memory, offset + 0x18);
 437         const u32   info = nvif_rd32(memory, offset + 0x1c);
 438         const u64   inst = (u64)insthi << 32 | instlo;
 439         const u8     gpc = (info & 0x1f000000) >> 24;
 440         const u8     hub = (info & 0x00100000) >> 20;
 441         const u8  client = (info & 0x00007f00) >> 8;
 442         struct nouveau_svm_fault *fault;
 443
 444         //XXX: i think we're supposed to spin waiting */
 445         if (WARN_ON(!(info & 0x80000000)))
 446                 return;
 447
 448         nvif_mask(memory, offset + 0x1c, 0x80000000, 0x00000000);
 449
 450         if (!buffer->fault[buffer->fault_nr]) {
 451                 fault = kmalloc(sizeof(*fault), GFP_KERNEL);
 452                 if (WARN_ON(!fault)) {
 453                         nouveau_svm_fault_cancel(svm, inst, hub, gpc, client);
 454                         return;
 455                 }
 456                 buffer->fault[buffer->fault_nr] = fault;
 457         }
 458
 459         fault = buffer->fault[buffer->fault_nr++];
 460         fault->inst   = inst;
 461         fault->addr   = (u64)addrhi << 32 | addrlo;
 462         fault->time   = (u64)timehi << 32 | timelo;
 463         fault->engine = engine;
 464         fault->gpc    = gpc;
 465         fault->hub    = hub;
 466         fault->access = (info & 0x000f0000) >> 16;
 467         fault->client = client;
 468         fault->fault  = (info & 0x0000001f);
 469
 470         SVM_DBG(svm, "fault %016llx %016llx %02x",
 471                 fault->inst, fault->addr, fault->access);
 472 }
 473
 474 struct svm_notifier {
 475         struct mmu_interval_notifier notifier;
 476         struct nouveau_svmm *svmm;
 477 };
 478
 479 static bool nouveau_svm_range_invalidate(struct mmu_interval_notifier *mni,
 480                                          const struct mmu_notifier_range *range,
 481                                          unsigned long cur_seq)
 482 {
 483         struct svm_notifier *sn =
 484                 container_of(mni, struct svm_notifier, notifier);
 485
 486         /*
 487          * serializes the update to mni->invalidate_seq done by caller and
 488          * prevents invalidation of the PTE from progressing while HW is being
 489          * programmed. This is very hacky and only works because the normal
 490          * notifier that does invalidation is always called after the range
 491          * notifier.
 492          */
 493         if (mmu_notifier_range_blockable(range))
 494                 mutex_lock(&sn->svmm->mutex);
 495         else if (!mutex_trylock(&sn->svmm->mutex))
 496                 return false;
 497         mmu_interval_set_seq(mni, cur_seq);
 498         mutex_unlock(&sn->svmm->mutex);
 499         return true;
 500 }
 501
 502 static const struct mmu_interval_notifier_ops nouveau_svm_mni_ops = {
 503         .invalidate = nouveau_svm_range_invalidate,
 504 };
 505
 506 static void nouveau_hmm_convert_pfn(struct nouveau_drm *drm,
 507                                     struct hmm_range *range,
 508                                     struct nouveau_pfnmap_args *args)
 509 {
 510         struct page *page;
 511
 512         /*
 513          * The address prepared here is passed through nvif_object_ioctl()
 514          * to an eventual DMA map in something like gp100_vmm_pgt_pfn()
 515          *
 516          * This is all just encoding the internal hmm representation into a
 517          * different nouveau internal representation.
 518          */
 519         if (!(range->hmm_pfns[0] & HMM_PFN_VALID)) {
 520                 args->p.phys[0] = 0;
 521                 return;
 522         }
 523
 524         page = hmm_pfn_to_page(range->hmm_pfns[0]);
 525         /*
 526          * Only map compound pages to the GPU if the CPU is also mapping the
 527          * page as a compound page. Otherwise, the PTE protections might not be
 528          * consistent (e.g., CPU only maps part of a compound page).
 529          * Note that the underlying page might still be larger than the
 530          * CPU mapping (e.g., a PUD sized compound page partially mapped with
 531          * a PMD sized page table entry).
 532          */
 533         if (hmm_pfn_to_map_order(range->hmm_pfns[0])) {
 534                 unsigned long addr = args->p.addr;
 535
 536                 args->p.page = hmm_pfn_to_map_order(range->hmm_pfns[0]) +
 537                                 PAGE_SHIFT;
 538                 args->p.size = 1UL << args->p.page;
 539                 args->p.addr &= ~(args->p.size - 1);
 540                 page -= (addr - args->p.addr) >> PAGE_SHIFT;
 541         }
 542         if (is_device_private_page(page))
 543                 args->p.phys[0] = nouveau_dmem_page_addr(page) |
 544                                 NVIF_VMM_PFNMAP_V0_V |
 545                                 NVIF_VMM_PFNMAP_V0_VRAM;
 546         else
 547                 args->p.phys[0] = page_to_phys(page) |
 548                                 NVIF_VMM_PFNMAP_V0_V |
 549                                 NVIF_VMM_PFNMAP_V0_HOST;
 550         if (range->hmm_pfns[0] & HMM_PFN_WRITE)
 551                 args->p.phys[0] |= NVIF_VMM_PFNMAP_V0_W;
 552 }
 553
 554 static int nouveau_range_fault(struct nouveau_svmm *svmm,
 555                                struct nouveau_drm *drm,
 556                                struct nouveau_pfnmap_args *args, u32 size,
 557                                unsigned long hmm_flags,
 558                                struct svm_notifier *notifier)
 559 {
 560         unsigned long timeout =
 561                 jiffies + msecs_to_jiffies(HMM_RANGE_DEFAULT_TIMEOUT);
 562         /* Have HMM fault pages within the fault window to the GPU. */
 563         unsigned long hmm_pfns[1];
 564         struct hmm_range range = {
 565                 .notifier = &notifier->notifier,
 566                 .start = notifier->notifier.interval_tree.start,
 567                 .end = notifier->notifier.interval_tree.last + 1,
 568                 .default_flags = hmm_flags,
 569                 .hmm_pfns = hmm_pfns,
 570                 .dev_private_owner = drm->dev,
 571         };
 572         struct mm_struct *mm = notifier->notifier.mm;
 573         int ret;
 574
 575         while (true) {
 576                 if (time_after(jiffies, timeout))
 577                         return -EBUSY;
 578
 579                 range.notifier_seq = mmu_interval_read_begin(range.notifier);
 580                 mmap_read_lock(mm);
 581                 ret = hmm_range_fault(&range);
 582                 mmap_read_unlock(mm);
 583                 if (ret) {
 584                         if (ret == -EBUSY)
 585                                 continue;
 586                         return ret;
 587                 }
 588
 589                 mutex_lock(&svmm->mutex);
 590                 if (mmu_interval_read_retry(range.notifier,
 591                                             range.notifier_seq)) {
 592                         mutex_unlock(&svmm->mutex);
 593                         continue;
 594                 }
 595                 break;
 596         }
 597
 598         nouveau_hmm_convert_pfn(drm, &range, args);
 599
 600         svmm->vmm->vmm.object.client->super = true;
 601         ret = nvif_object_ioctl(&svmm->vmm->vmm.object, args, size, NULL);
 602         svmm->vmm->vmm.object.client->super = false;
 603         mutex_unlock(&svmm->mutex);
 604
 605         return ret;
 606 }
 607
 608 static int
 609 nouveau_svm_fault(struct nvif_notify *notify)
 610 {
 611         struct nouveau_svm_fault_buffer *buffer =
 612                 container_of(notify, typeof(*buffer), notify);
 613         struct nouveau_svm *svm =
 614                 container_of(buffer, typeof(*svm), buffer[buffer->id]);
 615         struct nvif_object *device = &svm->drm->client.device.object;
 616         struct nouveau_svmm *svmm;
 617         struct {
 618                 struct nouveau_pfnmap_args i;
 619                 u64 phys[1];
 620         } args;
 621         unsigned long hmm_flags;
 622         u64 inst, start, limit;
 623         int fi, fn;
 624         int replay = 0, ret;
 625
 626         /* Parse available fault buffer entries into a cache, and update
 627          * the GET pointer so HW can reuse the entries.
 628          */
 629         SVM_DBG(svm, "fault handler");
 630         if (buffer->get == buffer->put) {
 631                 buffer->put = nvif_rd32(device, buffer->putaddr);
 632                 buffer->get = nvif_rd32(device, buffer->getaddr);
 633                 if (buffer->get == buffer->put)
 634                         return NVIF_NOTIFY_KEEP;
 635         }
 636         buffer->fault_nr = 0;
 637
 638         SVM_DBG(svm, "get %08x put %08x", buffer->get, buffer->put);
 639         while (buffer->get != buffer->put) {
 640                 nouveau_svm_fault_cache(svm, buffer, buffer->get * 0x20);
 641                 if (++buffer->get == buffer->entries)
 642                         buffer->get = 0;
 643         }
 644         nvif_wr32(device, buffer->getaddr, buffer->get);
 645         SVM_DBG(svm, "%d fault(s) pending", buffer->fault_nr);
 646
 647         /* Sort parsed faults by instance pointer to prevent unnecessary
 648          * instance to SVMM translations, followed by address and access
 649          * type to reduce the amount of work when handling the faults.
 650          */
 651         sort(buffer->fault, buffer->fault_nr, sizeof(*buffer->fault),
 652              nouveau_svm_fault_cmp, NULL);
 653
 654         /* Lookup SVMM structure for each unique instance pointer. */
 655         mutex_lock(&svm->mutex);
 656         for (fi = 0, svmm = NULL; fi < buffer->fault_nr; fi++) {
 657                 if (!svmm || buffer->fault[fi]->inst != inst) {
 658                         struct nouveau_ivmm *ivmm =
 659                                 nouveau_ivmm_find(svm, buffer->fault[fi]->inst);
 660                         svmm = ivmm ? ivmm->svmm : NULL;
 661                         inst = buffer->fault[fi]->inst;
 662                         SVM_DBG(svm, "inst %016llx -> svm-%p", inst, svmm);
 663                 }
 664                 buffer->fault[fi]->svmm = svmm;
 665         }
 666         mutex_unlock(&svm->mutex);
 667
 668         /* Process list of faults. */
 669         args.i.i.version = 0;
 670         args.i.i.type = NVIF_IOCTL_V0_MTHD;
 671         args.i.m.version = 0;
 672         args.i.m.method = NVIF_VMM_V0_PFNMAP;
 673         args.i.p.version = 0;
 674
 675         for (fi = 0; fn = fi + 1, fi < buffer->fault_nr; fi = fn) {
 676                 struct svm_notifier notifier;
 677                 struct mm_struct *mm;
 678
 679                 /* Cancel any faults from non-SVM channels. */
 680                 if (!(svmm = buffer->fault[fi]->svmm)) {
 681                         nouveau_svm_fault_cancel_fault(svm, buffer->fault[fi]);
 682                         continue;
 683                 }
 684                 SVMM_DBG(svmm, "addr %016llx", buffer->fault[fi]->addr);
 685
 686                 /* We try and group handling of faults within a small
 687                  * window into a single update.
 688                  */
 689                 start = buffer->fault[fi]->addr;
 690                 limit = start + PAGE_SIZE;
 691                 if (start < svmm->unmanaged.limit)
 692                         limit = min_t(u64, limit, svmm->unmanaged.start);
 693
 694                 /*
 695                  * Prepare the GPU-side update of all pages within the
 696                  * fault window, determining required pages and access
 697                  * permissions based on pending faults.
 698                  */
 699                 args.i.p.addr = start;
 700                 args.i.p.page = PAGE_SHIFT;
 701                 args.i.p.size = PAGE_SIZE;
 702                 /*
 703                  * Determine required permissions based on GPU fault
 704                  * access flags.
 705                  * XXX: atomic?
 706                  */
 707                 switch (buffer->fault[fi]->access) {
 708                 case 0: /* READ. */
 709                         hmm_flags = HMM_PFN_REQ_FAULT;
 710                         break;
 711                 case 3: /* PREFETCH. */
 712                         hmm_flags = 0;
 713                         break;
 714                 default:
 715                         hmm_flags = HMM_PFN_REQ_FAULT | HMM_PFN_REQ_WRITE;
 716                         break;
 717                 }
 718
 719                 mm = svmm->notifier.mm;
 720                 if (!mmget_not_zero(mm)) {
 721                         nouveau_svm_fault_cancel_fault(svm, buffer->fault[fi]);
 722                         continue;
 723                 }
 724
 725                 notifier.svmm = svmm;
 726                 ret = mmu_interval_notifier_insert(&notifier.notifier, mm,
 727                                                    args.i.p.addr, args.i.p.size,
 728                                                    &nouveau_svm_mni_ops);
 729                 if (!ret) {
 730                         ret = nouveau_range_fault(svmm, svm->drm, &args.i,
 731                                 sizeof(args), hmm_flags, &notifier);
 732                         mmu_interval_notifier_remove(&notifier.notifier);
 733                 }
 734                 mmput(mm);
 735
 736                 limit = args.i.p.addr + args.i.p.size;
 737                 for (fn = fi; ++fn < buffer->fault_nr; ) {
 738                         /* It's okay to skip over duplicate addresses from the
 739                          * same SVMM as faults are ordered by access type such
 740                          * that only the first one needs to be handled.
 741                          *
 742                          * ie. WRITE faults appear first, thus any handling of
 743                          * pending READ faults will already be satisfied.
 744                          * But if a large page is mapped, make sure subsequent
 745                          * fault addresses have sufficient access permission.
 746                          */
 747                         if (buffer->fault[fn]->svmm != svmm ||
 748                             buffer->fault[fn]->addr >= limit ||
 749                             (buffer->fault[fi]->access == 0 /* READ. */ &&
 750                              !(args.phys[0] & NVIF_VMM_PFNMAP_V0_V)) ||
 751                             (buffer->fault[fi]->access != 0 /* READ. */ &&
 752                              buffer->fault[fi]->access != 3 /* PREFETCH. */ &&
 753                              !(args.phys[0] & NVIF_VMM_PFNMAP_V0_W)))
 754                                 break;
 755                 }
 756
 757                 /* If handling failed completely, cancel all faults. */
 758                 if (ret) {
 759                         while (fi < fn) {
 760                                 struct nouveau_svm_fault *fault =
 761                                         buffer->fault[fi++];
 762
 763                                 nouveau_svm_fault_cancel_fault(svm, fault);
 764                         }
 765                 } else
 766                         replay++;
 767         }
 768
 769         /* Issue fault replay to the GPU. */
 770         if (replay)
 771                 nouveau_svm_fault_replay(svm);
 772         return NVIF_NOTIFY_KEEP;
 773 }
 774
 775 static struct nouveau_pfnmap_args *
 776 nouveau_pfns_to_args(void *pfns)
 777 {
 778         return container_of(pfns, struct nouveau_pfnmap_args, p.phys);
 779 }
 780
 781 u64 *
 782 nouveau_pfns_alloc(unsigned long npages)
 783 {
 784         struct nouveau_pfnmap_args *args;
 785
 786         args = kzalloc(struct_size(args, p.phys, npages), GFP_KERNEL);
 787         if (!args)
 788                 return NULL;
 789
 790         args->i.type = NVIF_IOCTL_V0_MTHD;
 791         args->m.method = NVIF_VMM_V0_PFNMAP;
 792         args->p.page = PAGE_SHIFT;
 793
 794         return args->p.phys;
 795 }
 796
 797 void
 798 nouveau_pfns_free(u64 *pfns)
 799 {
 800         struct nouveau_pfnmap_args *args = nouveau_pfns_to_args(pfns);
 801
 802         kfree(args);
 803 }
 804
 805 void
 806 nouveau_pfns_map(struct nouveau_svmm *svmm, struct mm_struct *mm,
 807                  unsigned long addr, u64 *pfns, unsigned long npages)
 808 {
 809         struct nouveau_pfnmap_args *args = nouveau_pfns_to_args(pfns);
 810         int ret;
 811
 812         args->p.addr = addr;
 813         args->p.size = npages << PAGE_SHIFT;
 814
 815         mutex_lock(&svmm->mutex);
 816
 817         svmm->vmm->vmm.object.client->super = true;
 818         ret = nvif_object_ioctl(&svmm->vmm->vmm.object, args, sizeof(*args) +
 819                                 npages * sizeof(args->p.phys[0]), NULL);
 820         svmm->vmm->vmm.object.client->super = false;
 821
 822         mutex_unlock(&svmm->mutex);
 823 }
 824
 825 static void
 826 nouveau_svm_fault_buffer_fini(struct nouveau_svm *svm, int id)
 827 {
 828         struct nouveau_svm_fault_buffer *buffer = &svm->buffer[id];
 829         nvif_notify_put(&buffer->notify);
 830 }
 831
 832 static int
 833 nouveau_svm_fault_buffer_init(struct nouveau_svm *svm, int id)
 834 {
 835         struct nouveau_svm_fault_buffer *buffer = &svm->buffer[id];
 836         struct nvif_object *device = &svm->drm->client.device.object;
 837         buffer->get = nvif_rd32(device, buffer->getaddr);
 838         buffer->put = nvif_rd32(device, buffer->putaddr);
 839         SVM_DBG(svm, "get %08x put %08x (init)", buffer->get, buffer->put);
 840         return nvif_notify_get(&buffer->notify);
 841 }
 842
 843 static void
 844 nouveau_svm_fault_buffer_dtor(struct nouveau_svm *svm, int id)
 845 {
 846         struct nouveau_svm_fault_buffer *buffer = &svm->buffer[id];
 847         int i;
 848
 849         if (buffer->fault) {
 850                 for (i = 0; buffer->fault[i] && i < buffer->entries; i++)
 851                         kfree(buffer->fault[i]);
 852                 kvfree(buffer->fault);
 853         }
 854
 855         nouveau_svm_fault_buffer_fini(svm, id);
 856
 857         nvif_notify_dtor(&buffer->notify);
 858         nvif_object_dtor(&buffer->object);
 859 }
 860
 861 static int
 862 nouveau_svm_fault_buffer_ctor(struct nouveau_svm *svm, s32 oclass, int id)
 863 {
 864         struct nouveau_svm_fault_buffer *buffer = &svm->buffer[id];
 865         struct nouveau_drm *drm = svm->drm;
 866         struct nvif_object *device = &drm->client.device.object;
 867         struct nvif_clb069_v0 args = {};
 868         int ret;
 869
 870         buffer->id = id;
 871
 872         ret = nvif_object_ctor(device, "svmFaultBuffer", 0, oclass, &args,
 873                                sizeof(args), &buffer->object);
 874         if (ret < 0) {
 875                 SVM_ERR(svm, "Fault buffer allocation failed: %d", ret);
 876                 return ret;
 877         }
 878
 879         nvif_object_map(&buffer->object, NULL, 0);
 880         buffer->entries = args.entries;
 881         buffer->getaddr = args.get;
 882         buffer->putaddr = args.put;
 883
 884         ret = nvif_notify_ctor(&buffer->object, "svmFault", nouveau_svm_fault,
 885                                true, NVB069_V0_NTFY_FAULT, NULL, 0, 0,
 886                                &buffer->notify);
 887         if (ret)
 888                 return ret;
 889
 890         buffer->fault = kvzalloc(sizeof(*buffer->fault) * buffer->entries, GFP_KERNEL);
 891         if (!buffer->fault)
 892                 return -ENOMEM;
 893
 894         return nouveau_svm_fault_buffer_init(svm, id);
 895 }
 896
 897 void
 898 nouveau_svm_resume(struct nouveau_drm *drm)
 899 {
 900         struct nouveau_svm *svm = drm->svm;
 901         if (svm)
 902                 nouveau_svm_fault_buffer_init(svm, 0);
 903 }
 904
 905 void
 906 nouveau_svm_suspend(struct nouveau_drm *drm)
 907 {
 908         struct nouveau_svm *svm = drm->svm;
 909         if (svm)
 910                 nouveau_svm_fault_buffer_fini(svm, 0);
 911 }
 912
 913 void
 914 nouveau_svm_fini(struct nouveau_drm *drm)
 915 {
 916         struct nouveau_svm *svm = drm->svm;
 917         if (svm) {
 918                 nouveau_svm_fault_buffer_dtor(svm, 0);
 919                 kfree(drm->svm);
 920                 drm->svm = NULL;
 921         }
 922 }
 923
 924 void
 925 nouveau_svm_init(struct nouveau_drm *drm)
 926 {
 927         static const struct nvif_mclass buffers[] = {
 928                 {   VOLTA_FAULT_BUFFER_A, 0 },
 929                 { MAXWELL_FAULT_BUFFER_A, 0 },
 930                 {}
 931         };
 932         struct nouveau_svm *svm;
 933         int ret;
 934
 935         /* Disable on Volta and newer until channel recovery is fixed,
 936          * otherwise clients will have a trivial way to trash the GPU
 937          * for everyone.
 938          */
 939         if (drm->client.device.info.family > NV_DEVICE_INFO_V0_PASCAL)
 940                 return;
 941
 942         if (!(drm->svm = svm = kzalloc(sizeof(*drm->svm), GFP_KERNEL)))
 943                 return;
 944
 945         drm->svm->drm = drm;
 946         mutex_init(&drm->svm->mutex);
 947         INIT_LIST_HEAD(&drm->svm->inst);
 948
 949         ret = nvif_mclass(&drm->client.device.object, buffers);
 950         if (ret < 0) {
 951                 SVM_DBG(svm, "No supported fault buffer class");
 952                 nouveau_svm_fini(drm);
 953                 return;
 954         }
 955
 956         ret = nouveau_svm_fault_buffer_ctor(svm, buffers[ret].oclass, 0);
 957         if (ret) {
 958                 nouveau_svm_fini(drm);
 959                 return;
 960         }
 961
 962         SVM_DBG(svm, "Initialised");
 963 }