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 struct nouveau_svmm {
  97         struct mmu_notifier notifier;
  98         struct nouveau_vmm *vmm;
  99         struct {
 100                 unsigned long start;
 101                 unsigned long limit;
 102         } unmanaged;
 103
 104         struct mutex mutex;
 105 };
 106
 107 #define SVMM_DBG(s,f,a...)                                                     \
 108         NV_DEBUG((s)->vmm->cli->drm, "svm-%p: "f"\n", (s), ##a)
 109 #define SVMM_ERR(s,f,a...)                                                     \
 110         NV_WARN((s)->vmm->cli->drm, "svm-%p: "f"\n", (s), ##a)
 111
 112 int
 113 nouveau_svmm_bind(struct drm_device *dev, void *data,
 114                   struct drm_file *file_priv)
 115 {
 116         struct nouveau_cli *cli = nouveau_cli(file_priv);
 117         struct drm_nouveau_svm_bind *args = data;
 118         unsigned target, cmd, priority;
 119         unsigned long addr, end, size;
 120         struct mm_struct *mm;
 121
 122         args->va_start &= PAGE_MASK;
 123         args->va_end &= PAGE_MASK;
 124
 125         /* Sanity check arguments */
 126         if (args->reserved0 || args->reserved1)
 127                 return -EINVAL;
 128         if (args->header & (~NOUVEAU_SVM_BIND_VALID_MASK))
 129                 return -EINVAL;
 130         if (args->va_start >= args->va_end)
 131                 return -EINVAL;
 132         if (!args->npages)
 133                 return -EINVAL;
 134
 135         cmd = args->header >> NOUVEAU_SVM_BIND_COMMAND_SHIFT;
 136         cmd &= NOUVEAU_SVM_BIND_COMMAND_MASK;
 137         switch (cmd) {
 138         case NOUVEAU_SVM_BIND_COMMAND__MIGRATE:
 139                 break;
 140         default:
 141                 return -EINVAL;
 142         }
 143
 144         priority = args->header >> NOUVEAU_SVM_BIND_PRIORITY_SHIFT;
 145         priority &= NOUVEAU_SVM_BIND_PRIORITY_MASK;
 146
 147         /* FIXME support CPU target ie all target value < GPU_VRAM */
 148         target = args->header >> NOUVEAU_SVM_BIND_TARGET_SHIFT;
 149         target &= NOUVEAU_SVM_BIND_TARGET_MASK;
 150         switch (target) {
 151         case NOUVEAU_SVM_BIND_TARGET__GPU_VRAM:
 152                 break;
 153         default:
 154                 return -EINVAL;
 155         }
 156
 157         /*
 158          * FIXME: For now refuse non 0 stride, we need to change the migrate
 159          * kernel function to handle stride to avoid to create a mess within
 160          * each device driver.
 161          */
 162         if (args->stride)
 163                 return -EINVAL;
 164
 165         size = ((unsigned long)args->npages) << PAGE_SHIFT;
 166         if ((args->va_start + size) <= args->va_start)
 167                 return -EINVAL;
 168         if ((args->va_start + size) > args->va_end)
 169                 return -EINVAL;
 170
 171         /*
 172          * Ok we are ask to do something sane, for now we only support migrate
 173          * commands but we will add things like memory policy (what to do on
 174          * page fault) and maybe some other commands.
 175          */
 176
 177         mm = get_task_mm(current);
 178         mmap_read_lock(mm);
 179
 180         if (!cli->svm.svmm) {
 181                 mmap_read_unlock(mm);
 182                 return -EINVAL;
 183         }
 184
 185         for (addr = args->va_start, end = args->va_start + size; addr < end;) {
 186                 struct vm_area_struct *vma;
 187                 unsigned long next;
 188
 189                 vma = find_vma_intersection(mm, addr, end);
 190                 if (!vma)
 191                         break;
 192
 193                 addr = max(addr, vma->vm_start);
 194                 next = min(vma->vm_end, end);
 195                 /* This is a best effort so we ignore errors */
 196                 nouveau_dmem_migrate_vma(cli->drm, cli->svm.svmm, vma, addr,
 197                                          next);
 198                 addr = next;
 199         }
 200
 201         /*
 202          * FIXME Return the number of page we have migrated, again we need to
 203          * update the migrate API to return that information so that we can
 204          * report it to user space.
 205          */
 206         args->result = 0;
 207
 208         mmap_read_unlock(mm);
 209         mmput(mm);
 210
 211         return 0;
 212 }
 213
 214 /* Unlink channel instance from SVMM. */
 215 void
 216 nouveau_svmm_part(struct nouveau_svmm *svmm, u64 inst)
 217 {
 218         struct nouveau_ivmm *ivmm;
 219         if (svmm) {
 220                 mutex_lock(&svmm->vmm->cli->drm->svm->mutex);
 221                 ivmm = nouveau_ivmm_find(svmm->vmm->cli->drm->svm, inst);
 222                 if (ivmm) {
 223                         list_del(&ivmm->head);
 224                         kfree(ivmm);
 225                 }
 226                 mutex_unlock(&svmm->vmm->cli->drm->svm->mutex);
 227         }
 228 }
 229
 230 /* Link channel instance to SVMM. */
 231 int
 232 nouveau_svmm_join(struct nouveau_svmm *svmm, u64 inst)
 233 {
 234         struct nouveau_ivmm *ivmm;
 235         if (svmm) {
 236                 if (!(ivmm = kmalloc(sizeof(*ivmm), GFP_KERNEL)))
 237                         return -ENOMEM;
 238                 ivmm->svmm = svmm;
 239                 ivmm->inst = inst;
 240
 241                 mutex_lock(&svmm->vmm->cli->drm->svm->mutex);
 242                 list_add(&ivmm->head, &svmm->vmm->cli->drm->svm->inst);
 243                 mutex_unlock(&svmm->vmm->cli->drm->svm->mutex);
 244         }
 245         return 0;
 246 }
 247
 248 /* Invalidate SVMM address-range on GPU. */
 249 static void
 250 nouveau_svmm_invalidate(struct nouveau_svmm *svmm, u64 start, u64 limit)
 251 {
 252         if (limit > start) {
 253                 bool super = svmm->vmm->vmm.object.client->super;
 254                 svmm->vmm->vmm.object.client->super = true;
 255                 nvif_object_mthd(&svmm->vmm->vmm.object, NVIF_VMM_V0_PFNCLR,
 256                                  &(struct nvif_vmm_pfnclr_v0) {
 257                                         .addr = start,
 258                                         .size = limit - start,
 259                                  }, sizeof(struct nvif_vmm_pfnclr_v0));
 260                 svmm->vmm->vmm.object.client->super = super;
 261         }
 262 }
 263
 264 static int
 265 nouveau_svmm_invalidate_range_start(struct mmu_notifier *mn,
 266                                     const struct mmu_notifier_range *update)
 267 {
 268         struct nouveau_svmm *svmm =
 269                 container_of(mn, struct nouveau_svmm, notifier);
 270         unsigned long start = update->start;
 271         unsigned long limit = update->end;
 272
 273         if (!mmu_notifier_range_blockable(update))
 274                 return -EAGAIN;
 275
 276         SVMM_DBG(svmm, "invalidate %016lx-%016lx", start, limit);
 277
 278         mutex_lock(&svmm->mutex);
 279         if (unlikely(!svmm->vmm))
 280                 goto out;
 281
 282         if (limit > svmm->unmanaged.start && start < svmm->unmanaged.limit) {
 283                 if (start < svmm->unmanaged.start) {
 284                         nouveau_svmm_invalidate(svmm, start,
 285                                                 svmm->unmanaged.limit);
 286                 }
 287                 start = svmm->unmanaged.limit;
 288         }
 289
 290         nouveau_svmm_invalidate(svmm, start, limit);
 291
 292 out:
 293         mutex_unlock(&svmm->mutex);
 294         return 0;
 295 }
 296
 297 static void nouveau_svmm_free_notifier(struct mmu_notifier *mn)
 298 {
 299         kfree(container_of(mn, struct nouveau_svmm, notifier));
 300 }
 301
 302 static const struct mmu_notifier_ops nouveau_mn_ops = {
 303         .invalidate_range_start = nouveau_svmm_invalidate_range_start,
 304         .free_notifier = nouveau_svmm_free_notifier,
 305 };
 306
 307 void
 308 nouveau_svmm_fini(struct nouveau_svmm **psvmm)
 309 {
 310         struct nouveau_svmm *svmm = *psvmm;
 311         if (svmm) {
 312                 mutex_lock(&svmm->mutex);
 313                 svmm->vmm = NULL;
 314                 mutex_unlock(&svmm->mutex);
 315                 mmu_notifier_put(&svmm->notifier);
 316                 *psvmm = NULL;
 317         }
 318 }
 319
 320 int
 321 nouveau_svmm_init(struct drm_device *dev, void *data,
 322                   struct drm_file *file_priv)
 323 {
 324         struct nouveau_cli *cli = nouveau_cli(file_priv);
 325         struct nouveau_svmm *svmm;
 326         struct drm_nouveau_svm_init *args = data;
 327         int ret;
 328
 329         /* Allocate tracking for SVM-enabled VMM. */
 330         if (!(svmm = kzalloc(sizeof(*svmm), GFP_KERNEL)))
 331                 return -ENOMEM;
 332         svmm->vmm = &cli->svm;
 333         svmm->unmanaged.start = args->unmanaged_addr;
 334         svmm->unmanaged.limit = args->unmanaged_addr + args->unmanaged_size;
 335         mutex_init(&svmm->mutex);
 336
 337         /* Check that SVM isn't already enabled for the client. */
 338         mutex_lock(&cli->mutex);
 339         if (cli->svm.cli) {
 340                 ret = -EBUSY;
 341                 goto out_free;
 342         }
 343
 344         /* Allocate a new GPU VMM that can support SVM (managed by the
 345          * client, with replayable faults enabled).
 346          *
 347          * All future channel/memory allocations will make use of this
 348          * VMM instead of the standard one.
 349          */
 350         ret = nvif_vmm_ctor(&cli->mmu, "svmVmm",
 351                             cli->vmm.vmm.object.oclass, true,
 352                             args->unmanaged_addr, args->unmanaged_size,
 353                             &(struct gp100_vmm_v0) {
 354                                 .fault_replay = true,
 355                             }, sizeof(struct gp100_vmm_v0), &cli->svm.vmm);
 356         if (ret)
 357                 goto out_free;
 358
 359         mmap_write_lock(current->mm);
 360         svmm->notifier.ops = &nouveau_mn_ops;
 361         ret = __mmu_notifier_register(&svmm->notifier, current->mm);
 362         if (ret)
 363                 goto out_mm_unlock;
 364         /* Note, ownership of svmm transfers to mmu_notifier */
 365
 366         cli->svm.svmm = svmm;
 367         cli->svm.cli = cli;
 368         mmap_write_unlock(current->mm);
 369         mutex_unlock(&cli->mutex);
 370         return 0;
 371
 372 out_mm_unlock:
 373         mmap_write_unlock(current->mm);
 374 out_free:
 375         mutex_unlock(&cli->mutex);
 376         kfree(svmm);
 377         return ret;
 378 }
 379
 380 /* Issue fault replay for GPU to retry accesses that faulted previously. */
 381 static void
 382 nouveau_svm_fault_replay(struct nouveau_svm *svm)
 383 {
 384         SVM_DBG(svm, "replay");
 385         WARN_ON(nvif_object_mthd(&svm->drm->client.vmm.vmm.object,
 386                                  GP100_VMM_VN_FAULT_REPLAY,
 387                                  &(struct gp100_vmm_fault_replay_vn) {},
 388                                  sizeof(struct gp100_vmm_fault_replay_vn)));
 389 }
 390
 391 /* Cancel a replayable fault that could not be handled.
 392  *
 393  * Cancelling the fault will trigger recovery to reset the engine
 394  * and kill the offending channel (ie. GPU SIGSEGV).
 395  */
 396 static void
 397 nouveau_svm_fault_cancel(struct nouveau_svm *svm,
 398                          u64 inst, u8 hub, u8 gpc, u8 client)
 399 {
 400         SVM_DBG(svm, "cancel %016llx %d %02x %02x", inst, hub, gpc, client);
 401         WARN_ON(nvif_object_mthd(&svm->drm->client.vmm.vmm.object,
 402                                  GP100_VMM_VN_FAULT_CANCEL,
 403                                  &(struct gp100_vmm_fault_cancel_v0) {
 404                                         .hub = hub,
 405                                         .gpc = gpc,
 406                                         .client = client,
 407                                         .inst = inst,
 408                                  }, sizeof(struct gp100_vmm_fault_cancel_v0)));
 409 }
 410
 411 static void
 412 nouveau_svm_fault_cancel_fault(struct nouveau_svm *svm,
 413                                struct nouveau_svm_fault *fault)
 414 {
 415         nouveau_svm_fault_cancel(svm, fault->inst,
 416                                       fault->hub,
 417                                       fault->gpc,
 418                                       fault->client);
 419 }
 420
 421 static int
 422 nouveau_svm_fault_cmp(const void *a, const void *b)
 423 {
 424         const struct nouveau_svm_fault *fa = *(struct nouveau_svm_fault **)a;
 425         const struct nouveau_svm_fault *fb = *(struct nouveau_svm_fault **)b;
 426         int ret;
 427         if ((ret = (s64)fa->inst - fb->inst))
 428                 return ret;
 429         if ((ret = (s64)fa->addr - fb->addr))
 430                 return ret;
 431         /*XXX: atomic? */
 432         return (fa->access == 0 || fa->access == 3) -
 433                (fb->access == 0 || fb->access == 3);
 434 }
 435
 436 static void
 437 nouveau_svm_fault_cache(struct nouveau_svm *svm,
 438                         struct nouveau_svm_fault_buffer *buffer, u32 offset)
 439 {
 440         struct nvif_object *memory = &buffer->object;
 441         const u32 instlo = nvif_rd32(memory, offset + 0x00);
 442         const u32 insthi = nvif_rd32(memory, offset + 0x04);
 443         const u32 addrlo = nvif_rd32(memory, offset + 0x08);
 444         const u32 addrhi = nvif_rd32(memory, offset + 0x0c);
 445         const u32 timelo = nvif_rd32(memory, offset + 0x10);
 446         const u32 timehi = nvif_rd32(memory, offset + 0x14);
 447         const u32 engine = nvif_rd32(memory, offset + 0x18);
 448         const u32   info = nvif_rd32(memory, offset + 0x1c);
 449         const u64   inst = (u64)insthi << 32 | instlo;
 450         const u8     gpc = (info & 0x1f000000) >> 24;
 451         const u8     hub = (info & 0x00100000) >> 20;
 452         const u8  client = (info & 0x00007f00) >> 8;
 453         struct nouveau_svm_fault *fault;
 454
 455         //XXX: i think we're supposed to spin waiting */
 456         if (WARN_ON(!(info & 0x80000000)))
 457                 return;
 458
 459         nvif_mask(memory, offset + 0x1c, 0x80000000, 0x00000000);
 460
 461         if (!buffer->fault[buffer->fault_nr]) {
 462                 fault = kmalloc(sizeof(*fault), GFP_KERNEL);
 463                 if (WARN_ON(!fault)) {
 464                         nouveau_svm_fault_cancel(svm, inst, hub, gpc, client);
 465                         return;
 466                 }
 467                 buffer->fault[buffer->fault_nr] = fault;
 468         }
 469
 470         fault = buffer->fault[buffer->fault_nr++];
 471         fault->inst   = inst;
 472         fault->addr   = (u64)addrhi << 32 | addrlo;
 473         fault->time   = (u64)timehi << 32 | timelo;
 474         fault->engine = engine;
 475         fault->gpc    = gpc;
 476         fault->hub    = hub;
 477         fault->access = (info & 0x000f0000) >> 16;
 478         fault->client = client;
 479         fault->fault  = (info & 0x0000001f);
 480
 481         SVM_DBG(svm, "fault %016llx %016llx %02x",
 482                 fault->inst, fault->addr, fault->access);
 483 }
 484
 485 struct svm_notifier {
 486         struct mmu_interval_notifier notifier;
 487         struct nouveau_svmm *svmm;
 488 };
 489
 490 static bool nouveau_svm_range_invalidate(struct mmu_interval_notifier *mni,
 491                                          const struct mmu_notifier_range *range,
 492                                          unsigned long cur_seq)
 493 {
 494         struct svm_notifier *sn =
 495                 container_of(mni, struct svm_notifier, notifier);
 496
 497         /*
 498          * serializes the update to mni->invalidate_seq done by caller and
 499          * prevents invalidation of the PTE from progressing while HW is being
 500          * programmed. This is very hacky and only works because the normal
 501          * notifier that does invalidation is always called after the range
 502          * notifier.
 503          */
 504         if (mmu_notifier_range_blockable(range))
 505                 mutex_lock(&sn->svmm->mutex);
 506         else if (!mutex_trylock(&sn->svmm->mutex))
 507                 return false;
 508         mmu_interval_set_seq(mni, cur_seq);
 509         mutex_unlock(&sn->svmm->mutex);
 510         return true;
 511 }
 512
 513 static const struct mmu_interval_notifier_ops nouveau_svm_mni_ops = {
 514         .invalidate = nouveau_svm_range_invalidate,
 515 };
 516
 517 static void nouveau_hmm_convert_pfn(struct nouveau_drm *drm,
 518                                     struct hmm_range *range, u64 *ioctl_addr)
 519 {
 520         unsigned long i, npages;
 521
 522         /*
 523          * The ioctl_addr prepared here is passed through nvif_object_ioctl()
 524          * to an eventual DMA map in something like gp100_vmm_pgt_pfn()
 525          *
 526          * This is all just encoding the internal hmm representation into a
 527          * different nouveau internal representation.
 528          */
 529         npages = (range->end - range->start) >> PAGE_SHIFT;
 530         for (i = 0; i < npages; ++i) {
 531                 struct page *page;
 532
 533                 if (!(range->hmm_pfns[i] & HMM_PFN_VALID)) {
 534                         ioctl_addr[i] = 0;
 535                         continue;
 536                 }
 537
 538                 page = hmm_pfn_to_page(range->hmm_pfns[i]);
 539                 if (is_device_private_page(page))
 540                         ioctl_addr[i] = nouveau_dmem_page_addr(page) |
 541                                         NVIF_VMM_PFNMAP_V0_V |
 542                                         NVIF_VMM_PFNMAP_V0_VRAM;
 543                 else
 544                         ioctl_addr[i] = page_to_phys(page) |
 545                                         NVIF_VMM_PFNMAP_V0_V |
 546                                         NVIF_VMM_PFNMAP_V0_HOST;
 547                 if (range->hmm_pfns[i] & HMM_PFN_WRITE)
 548                         ioctl_addr[i] |= NVIF_VMM_PFNMAP_V0_W;
 549         }
 550 }
 551
 552 static int nouveau_range_fault(struct nouveau_svmm *svmm,
 553                                struct nouveau_drm *drm, void *data, u32 size,
 554                                unsigned long hmm_pfns[], u64 *ioctl_addr,
 555                                struct svm_notifier *notifier)
 556 {
 557         unsigned long timeout =
 558                 jiffies + msecs_to_jiffies(HMM_RANGE_DEFAULT_TIMEOUT);
 559         /* Have HMM fault pages within the fault window to the GPU. */
 560         struct hmm_range range = {
 561                 .notifier = &notifier->notifier,
 562                 .start = notifier->notifier.interval_tree.start,
 563                 .end = notifier->notifier.interval_tree.last + 1,
 564                 .pfn_flags_mask = HMM_PFN_REQ_FAULT | HMM_PFN_REQ_WRITE,
 565                 .hmm_pfns = hmm_pfns,
 566                 .dev_private_owner = drm->dev,
 567         };
 568         struct mm_struct *mm = notifier->notifier.mm;
 569         int ret;
 570
 571         while (true) {
 572                 if (time_after(jiffies, timeout))
 573                         return -EBUSY;
 574
 575                 range.notifier_seq = mmu_interval_read_begin(range.notifier);
 576                 mmap_read_lock(mm);
 577                 ret = hmm_range_fault(&range);
 578                 mmap_read_unlock(mm);
 579                 if (ret) {
 580                         /*
 581                          * FIXME: the input PFN_REQ flags are destroyed on
 582                          * -EBUSY, we need to regenerate them, also for the
 583                          * other continue below
 584                          */
 585                         if (ret == -EBUSY)
 586                                 continue;
 587                         return ret;
 588                 }
 589
 590                 mutex_lock(&svmm->mutex);
 591                 if (mmu_interval_read_retry(range.notifier,
 592                                             range.notifier_seq)) {
 593                         mutex_unlock(&svmm->mutex);
 594                         continue;
 595                 }
 596                 break;
 597         }
 598
 599         nouveau_hmm_convert_pfn(drm, &range, ioctl_addr);
 600
 601         svmm->vmm->vmm.object.client->super = true;
 602         ret = nvif_object_ioctl(&svmm->vmm->vmm.object, data, size, NULL);
 603         svmm->vmm->vmm.object.client->super = false;
 604         mutex_unlock(&svmm->mutex);
 605
 606         return ret;
 607 }
 608
 609 static int
 610 nouveau_svm_fault(struct nvif_notify *notify)
 611 {
 612         struct nouveau_svm_fault_buffer *buffer =
 613                 container_of(notify, typeof(*buffer), notify);
 614         struct nouveau_svm *svm =
 615                 container_of(buffer, typeof(*svm), buffer[buffer->id]);
 616         struct nvif_object *device = &svm->drm->client.device.object;
 617         struct nouveau_svmm *svmm;
 618         struct {
 619                 struct {
 620                         struct nvif_ioctl_v0 i;
 621                         struct nvif_ioctl_mthd_v0 m;
 622                         struct nvif_vmm_pfnmap_v0 p;
 623                 } i;
 624                 u64 phys[16];
 625         } args;
 626         unsigned long hmm_pfns[ARRAY_SIZE(args.phys)];
 627         struct vm_area_struct *vma;
 628         u64 inst, start, limit;
 629         int fi, fn, pi, fill;
 630         int replay = 0, ret;
 631
 632         /* Parse available fault buffer entries into a cache, and update
 633          * the GET pointer so HW can reuse the entries.
 634          */
 635         SVM_DBG(svm, "fault handler");
 636         if (buffer->get == buffer->put) {
 637                 buffer->put = nvif_rd32(device, buffer->putaddr);
 638                 buffer->get = nvif_rd32(device, buffer->getaddr);
 639                 if (buffer->get == buffer->put)
 640                         return NVIF_NOTIFY_KEEP;
 641         }
 642         buffer->fault_nr = 0;
 643
 644         SVM_DBG(svm, "get %08x put %08x", buffer->get, buffer->put);
 645         while (buffer->get != buffer->put) {
 646                 nouveau_svm_fault_cache(svm, buffer, buffer->get * 0x20);
 647                 if (++buffer->get == buffer->entries)
 648                         buffer->get = 0;
 649         }
 650         nvif_wr32(device, buffer->getaddr, buffer->get);
 651         SVM_DBG(svm, "%d fault(s) pending", buffer->fault_nr);
 652
 653         /* Sort parsed faults by instance pointer to prevent unnecessary
 654          * instance to SVMM translations, followed by address and access
 655          * type to reduce the amount of work when handling the faults.
 656          */
 657         sort(buffer->fault, buffer->fault_nr, sizeof(*buffer->fault),
 658              nouveau_svm_fault_cmp, NULL);
 659
 660         /* Lookup SVMM structure for each unique instance pointer. */
 661         mutex_lock(&svm->mutex);
 662         for (fi = 0, svmm = NULL; fi < buffer->fault_nr; fi++) {
 663                 if (!svmm || buffer->fault[fi]->inst != inst) {
 664                         struct nouveau_ivmm *ivmm =
 665                                 nouveau_ivmm_find(svm, buffer->fault[fi]->inst);
 666                         svmm = ivmm ? ivmm->svmm : NULL;
 667                         inst = buffer->fault[fi]->inst;
 668                         SVM_DBG(svm, "inst %016llx -> svm-%p", inst, svmm);
 669                 }
 670                 buffer->fault[fi]->svmm = svmm;
 671         }
 672         mutex_unlock(&svm->mutex);
 673
 674         /* Process list of faults. */
 675         args.i.i.version = 0;
 676         args.i.i.type = NVIF_IOCTL_V0_MTHD;
 677         args.i.m.version = 0;
 678         args.i.m.method = NVIF_VMM_V0_PFNMAP;
 679         args.i.p.version = 0;
 680
 681         for (fi = 0; fn = fi + 1, fi < buffer->fault_nr; fi = fn) {
 682                 struct svm_notifier notifier;
 683                 struct mm_struct *mm;
 684
 685                 /* Cancel any faults from non-SVM channels. */
 686                 if (!(svmm = buffer->fault[fi]->svmm)) {
 687                         nouveau_svm_fault_cancel_fault(svm, buffer->fault[fi]);
 688                         continue;
 689                 }
 690                 SVMM_DBG(svmm, "addr %016llx", buffer->fault[fi]->addr);
 691
 692                 /* We try and group handling of faults within a small
 693                  * window into a single update.
 694                  */
 695                 start = buffer->fault[fi]->addr;
 696                 limit = start + (ARRAY_SIZE(args.phys) << PAGE_SHIFT);
 697                 if (start < svmm->unmanaged.limit)
 698                         limit = min_t(u64, limit, svmm->unmanaged.start);
 699                 SVMM_DBG(svmm, "wndw %016llx-%016llx", start, limit);
 700
 701                 mm = svmm->notifier.mm;
 702                 if (!mmget_not_zero(mm)) {
 703                         nouveau_svm_fault_cancel_fault(svm, buffer->fault[fi]);
 704                         continue;
 705                 }
 706
 707                 /* Intersect fault window with the CPU VMA, cancelling
 708                  * the fault if the address is invalid.
 709                  */
 710                 mmap_read_lock(mm);
 711                 vma = find_vma_intersection(mm, start, limit);
 712                 if (!vma) {
 713                         SVMM_ERR(svmm, "wndw %016llx-%016llx", start, limit);
 714                         mmap_read_unlock(mm);
 715                         mmput(mm);
 716                         nouveau_svm_fault_cancel_fault(svm, buffer->fault[fi]);
 717                         continue;
 718                 }
 719                 start = max_t(u64, start, vma->vm_start);
 720                 limit = min_t(u64, limit, vma->vm_end);
 721                 mmap_read_unlock(mm);
 722                 SVMM_DBG(svmm, "wndw %016llx-%016llx", start, limit);
 723
 724                 if (buffer->fault[fi]->addr != start) {
 725                         SVMM_ERR(svmm, "addr %016llx", buffer->fault[fi]->addr);
 726                         mmput(mm);
 727                         nouveau_svm_fault_cancel_fault(svm, buffer->fault[fi]);
 728                         continue;
 729                 }
 730
 731                 /* Prepare the GPU-side update of all pages within the
 732                  * fault window, determining required pages and access
 733                  * permissions based on pending faults.
 734                  */
 735                 args.i.p.page = PAGE_SHIFT;
 736                 args.i.p.addr = start;
 737                 for (fn = fi, pi = 0;;) {
 738                         /* Determine required permissions based on GPU fault
 739                          * access flags.
 740                          *XXX: atomic?
 741                          */
 742                         switch (buffer->fault[fn]->access) {
 743                         case 0: /* READ. */
 744                                 hmm_pfns[pi++] = HMM_PFN_REQ_FAULT;
 745                                 break;
 746                         case 3: /* PREFETCH. */
 747                                 hmm_pfns[pi++] = 0;
 748                                 break;
 749                         default:
 750                                 hmm_pfns[pi++] = HMM_PFN_REQ_FAULT |
 751                                                  HMM_PFN_REQ_WRITE;
 752                                 break;
 753                         }
 754                         args.i.p.size = pi << PAGE_SHIFT;
 755
 756                         /* It's okay to skip over duplicate addresses from the
 757                          * same SVMM as faults are ordered by access type such
 758                          * that only the first one needs to be handled.
 759                          *
 760                          * ie. WRITE faults appear first, thus any handling of
 761                          * pending READ faults will already be satisfied.
 762                          */
 763                         while (++fn < buffer->fault_nr &&
 764                                buffer->fault[fn]->svmm == svmm &&
 765                                buffer->fault[fn    ]->addr ==
 766                                buffer->fault[fn - 1]->addr);
 767
 768                         /* If the next fault is outside the window, or all GPU
 769                          * faults have been dealt with, we're done here.
 770                          */
 771                         if (fn >= buffer->fault_nr ||
 772                             buffer->fault[fn]->svmm != svmm ||
 773                             buffer->fault[fn]->addr >= limit)
 774                                 break;
 775
 776                         /* Fill in the gap between this fault and the next. */
 777                         fill = (buffer->fault[fn    ]->addr -
 778                                 buffer->fault[fn - 1]->addr) >> PAGE_SHIFT;
 779                         while (--fill)
 780                                 hmm_pfns[pi++] = 0;
 781                 }
 782
 783                 SVMM_DBG(svmm, "wndw %016llx-%016llx covering %d fault(s)",
 784                          args.i.p.addr,
 785                          args.i.p.addr + args.i.p.size, fn - fi);
 786
 787                 notifier.svmm = svmm;
 788                 ret = mmu_interval_notifier_insert(&notifier.notifier,
 789                                                    svmm->notifier.mm,
 790                                                    args.i.p.addr, args.i.p.size,
 791                                                    &nouveau_svm_mni_ops);
 792                 if (!ret) {
 793                         ret = nouveau_range_fault(
 794                                 svmm, svm->drm, &args,
 795                                 sizeof(args.i) + pi * sizeof(args.phys[0]),
 796                                 hmm_pfns, args.phys, &notifier);
 797                         mmu_interval_notifier_remove(&notifier.notifier);
 798                 }
 799                 mmput(mm);
 800
 801                 /* Cancel any faults in the window whose pages didn't manage
 802                  * to keep their valid bit, or stay writeable when required.
 803                  *
 804                  * If handling failed completely, cancel all faults.
 805                  */
 806                 while (fi < fn) {
 807                         struct nouveau_svm_fault *fault = buffer->fault[fi++];
 808                         pi = (fault->addr - args.i.p.addr) >> PAGE_SHIFT;
 809                         if (ret ||
 810                              !(args.phys[pi] & NVIF_VMM_PFNMAP_V0_V) ||
 811                             (!(args.phys[pi] & NVIF_VMM_PFNMAP_V0_W) &&
 812                              fault->access != 0 && fault->access != 3)) {
 813                                 nouveau_svm_fault_cancel_fault(svm, fault);
 814                                 continue;
 815                         }
 816                         replay++;
 817                 }
 818         }
 819
 820         /* Issue fault replay to the GPU. */
 821         if (replay)
 822                 nouveau_svm_fault_replay(svm);
 823         return NVIF_NOTIFY_KEEP;
 824 }
 825
 826 static struct nouveau_pfnmap_args *
 827 nouveau_pfns_to_args(void *pfns)
 828 {
 829         return container_of(pfns, struct nouveau_pfnmap_args, p.phys);
 830 }
 831
 832 u64 *
 833 nouveau_pfns_alloc(unsigned long npages)
 834 {
 835         struct nouveau_pfnmap_args *args;
 836
 837         args = kzalloc(struct_size(args, p.phys, npages), GFP_KERNEL);
 838         if (!args)
 839                 return NULL;
 840
 841         args->i.type = NVIF_IOCTL_V0_MTHD;
 842         args->m.method = NVIF_VMM_V0_PFNMAP;
 843         args->p.page = PAGE_SHIFT;
 844
 845         return args->p.phys;
 846 }
 847
 848 void
 849 nouveau_pfns_free(u64 *pfns)
 850 {
 851         struct nouveau_pfnmap_args *args = nouveau_pfns_to_args(pfns);
 852
 853         kfree(args);
 854 }
 855
 856 void
 857 nouveau_pfns_map(struct nouveau_svmm *svmm, struct mm_struct *mm,
 858                  unsigned long addr, u64 *pfns, unsigned long npages)
 859 {
 860         struct nouveau_pfnmap_args *args = nouveau_pfns_to_args(pfns);
 861         int ret;
 862
 863         args->p.addr = addr;
 864         args->p.size = npages << PAGE_SHIFT;
 865
 866         mutex_lock(&svmm->mutex);
 867
 868         svmm->vmm->vmm.object.client->super = true;
 869         ret = nvif_object_ioctl(&svmm->vmm->vmm.object, args, sizeof(*args) +
 870                                 npages * sizeof(args->p.phys[0]), NULL);
 871         svmm->vmm->vmm.object.client->super = false;
 872
 873         mutex_unlock(&svmm->mutex);
 874 }
 875
 876 static void
 877 nouveau_svm_fault_buffer_fini(struct nouveau_svm *svm, int id)
 878 {
 879         struct nouveau_svm_fault_buffer *buffer = &svm->buffer[id];
 880         nvif_notify_put(&buffer->notify);
 881 }
 882
 883 static int
 884 nouveau_svm_fault_buffer_init(struct nouveau_svm *svm, int id)
 885 {
 886         struct nouveau_svm_fault_buffer *buffer = &svm->buffer[id];
 887         struct nvif_object *device = &svm->drm->client.device.object;
 888         buffer->get = nvif_rd32(device, buffer->getaddr);
 889         buffer->put = nvif_rd32(device, buffer->putaddr);
 890         SVM_DBG(svm, "get %08x put %08x (init)", buffer->get, buffer->put);
 891         return nvif_notify_get(&buffer->notify);
 892 }
 893
 894 static void
 895 nouveau_svm_fault_buffer_dtor(struct nouveau_svm *svm, int id)
 896 {
 897         struct nouveau_svm_fault_buffer *buffer = &svm->buffer[id];
 898         int i;
 899
 900         if (buffer->fault) {
 901                 for (i = 0; buffer->fault[i] && i < buffer->entries; i++)
 902                         kfree(buffer->fault[i]);
 903                 kvfree(buffer->fault);
 904         }
 905
 906         nouveau_svm_fault_buffer_fini(svm, id);
 907
 908         nvif_notify_dtor(&buffer->notify);
 909         nvif_object_dtor(&buffer->object);
 910 }
 911
 912 static int
 913 nouveau_svm_fault_buffer_ctor(struct nouveau_svm *svm, s32 oclass, int id)
 914 {
 915         struct nouveau_svm_fault_buffer *buffer = &svm->buffer[id];
 916         struct nouveau_drm *drm = svm->drm;
 917         struct nvif_object *device = &drm->client.device.object;
 918         struct nvif_clb069_v0 args = {};
 919         int ret;
 920
 921         buffer->id = id;
 922
 923         ret = nvif_object_ctor(device, "svmFaultBuffer", 0, oclass, &args,
 924                                sizeof(args), &buffer->object);
 925         if (ret < 0) {
 926                 SVM_ERR(svm, "Fault buffer allocation failed: %d", ret);
 927                 return ret;
 928         }
 929
 930         nvif_object_map(&buffer->object, NULL, 0);
 931         buffer->entries = args.entries;
 932         buffer->getaddr = args.get;
 933         buffer->putaddr = args.put;
 934
 935         ret = nvif_notify_ctor(&buffer->object, "svmFault", nouveau_svm_fault,
 936                                true, NVB069_V0_NTFY_FAULT, NULL, 0, 0,
 937                                &buffer->notify);
 938         if (ret)
 939                 return ret;
 940
 941         buffer->fault = kvzalloc(sizeof(*buffer->fault) * buffer->entries, GFP_KERNEL);
 942         if (!buffer->fault)
 943                 return -ENOMEM;
 944
 945         return nouveau_svm_fault_buffer_init(svm, id);
 946 }
 947
 948 void
 949 nouveau_svm_resume(struct nouveau_drm *drm)
 950 {
 951         struct nouveau_svm *svm = drm->svm;
 952         if (svm)
 953                 nouveau_svm_fault_buffer_init(svm, 0);
 954 }
 955
 956 void
 957 nouveau_svm_suspend(struct nouveau_drm *drm)
 958 {
 959         struct nouveau_svm *svm = drm->svm;
 960         if (svm)
 961                 nouveau_svm_fault_buffer_fini(svm, 0);
 962 }
 963
 964 void
 965 nouveau_svm_fini(struct nouveau_drm *drm)
 966 {
 967         struct nouveau_svm *svm = drm->svm;
 968         if (svm) {
 969                 nouveau_svm_fault_buffer_dtor(svm, 0);
 970                 kfree(drm->svm);
 971                 drm->svm = NULL;
 972         }
 973 }
 974
 975 void
 976 nouveau_svm_init(struct nouveau_drm *drm)
 977 {
 978         static const struct nvif_mclass buffers[] = {
 979                 {   VOLTA_FAULT_BUFFER_A, 0 },
 980                 { MAXWELL_FAULT_BUFFER_A, 0 },
 981                 {}
 982         };
 983         struct nouveau_svm *svm;
 984         int ret;
 985
 986         /* Disable on Volta and newer until channel recovery is fixed,
 987          * otherwise clients will have a trivial way to trash the GPU
 988          * for everyone.
 989          */
 990         if (drm->client.device.info.family > NV_DEVICE_INFO_V0_PASCAL)
 991                 return;
 992
 993         if (!(drm->svm = svm = kzalloc(sizeof(*drm->svm), GFP_KERNEL)))
 994                 return;
 995
 996         drm->svm->drm = drm;
 997         mutex_init(&drm->svm->mutex);
 998         INIT_LIST_HEAD(&drm->svm->inst);
 999
1000         ret = nvif_mclass(&drm->client.device.object, buffers);
1001         if (ret < 0) {
1002                 SVM_DBG(svm, "No supported fault buffer class");
1003                 nouveau_svm_fini(drm);
1004                 return;
1005         }
1006
1007         ret = nouveau_svm_fault_buffer_ctor(svm, buffers[ret].oclass, 0);
1008         if (ret) {
1009                 nouveau_svm_fini(drm);
1010                 return;
1011         }
1012
1013         SVM_DBG(svm, "Initialised");
1014 }