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->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         /* We need to fail if svm is disabled */
 319         if (!cli->drm->svm)
 320                 return -ENOSYS;
 321
 322         /* Allocate tracking for SVM-enabled VMM. */
 323         if (!(svmm = kzalloc(sizeof(*svmm), GFP_KERNEL)))
 324                 return -ENOMEM;
 325         svmm->vmm = &cli->svm;
 326         svmm->unmanaged.start = args->unmanaged_addr;
 327         svmm->unmanaged.limit = args->unmanaged_addr + args->unmanaged_size;
 328         mutex_init(&svmm->mutex);
 329
 330         /* Check that SVM isn't already enabled for the client. */
 331         mutex_lock(&cli->mutex);
 332         if (cli->svm.cli) {
 333                 ret = -EBUSY;
 334                 goto out_free;
 335         }
 336
 337         /* Allocate a new GPU VMM that can support SVM (managed by the
 338          * client, with replayable faults enabled).
 339          *
 340          * All future channel/memory allocations will make use of this
 341          * VMM instead of the standard one.
 342          */
 343         ret = nvif_vmm_ctor(&cli->mmu, "svmVmm",
 344                             cli->vmm.vmm.object.oclass, true,
 345                             args->unmanaged_addr, args->unmanaged_size,
 346                             &(struct gp100_vmm_v0) {
 347                                 .fault_replay = true,
 348                             }, sizeof(struct gp100_vmm_v0), &cli->svm.vmm);
 349         if (ret)
 350                 goto out_free;
 351
 352         mmap_write_lock(current->mm);
 353         svmm->notifier.ops = &nouveau_mn_ops;
 354         ret = __mmu_notifier_register(&svmm->notifier, current->mm);
 355         if (ret)
 356                 goto out_mm_unlock;
 357         /* Note, ownership of svmm transfers to mmu_notifier */
 358
 359         cli->svm.svmm = svmm;
 360         cli->svm.cli = cli;
 361         mmap_write_unlock(current->mm);
 362         mutex_unlock(&cli->mutex);
 363         return 0;
 364
 365 out_mm_unlock:
 366         mmap_write_unlock(current->mm);
 367 out_free:
 368         mutex_unlock(&cli->mutex);
 369         kfree(svmm);
 370         return ret;
 371 }
 372
 373 /* Issue fault replay for GPU to retry accesses that faulted previously. */
 374 static void
 375 nouveau_svm_fault_replay(struct nouveau_svm *svm)
 376 {
 377         SVM_DBG(svm, "replay");
 378         WARN_ON(nvif_object_mthd(&svm->drm->client.vmm.vmm.object,
 379                                  GP100_VMM_VN_FAULT_REPLAY,
 380                                  &(struct gp100_vmm_fault_replay_vn) {},
 381                                  sizeof(struct gp100_vmm_fault_replay_vn)));
 382 }
 383
 384 /* Cancel a replayable fault that could not be handled.
 385  *
 386  * Cancelling the fault will trigger recovery to reset the engine
 387  * and kill the offending channel (ie. GPU SIGSEGV).
 388  */
 389 static void
 390 nouveau_svm_fault_cancel(struct nouveau_svm *svm,
 391                          u64 inst, u8 hub, u8 gpc, u8 client)
 392 {
 393         SVM_DBG(svm, "cancel %016llx %d %02x %02x", inst, hub, gpc, client);
 394         WARN_ON(nvif_object_mthd(&svm->drm->client.vmm.vmm.object,
 395                                  GP100_VMM_VN_FAULT_CANCEL,
 396                                  &(struct gp100_vmm_fault_cancel_v0) {
 397                                         .hub = hub,
 398                                         .gpc = gpc,
 399                                         .client = client,
 400                                         .inst = inst,
 401                                  }, sizeof(struct gp100_vmm_fault_cancel_v0)));
 402 }
 403
 404 static void
 405 nouveau_svm_fault_cancel_fault(struct nouveau_svm *svm,
 406                                struct nouveau_svm_fault *fault)
 407 {
 408         nouveau_svm_fault_cancel(svm, fault->inst,
 409                                       fault->hub,
 410                                       fault->gpc,
 411                                       fault->client);
 412 }
 413
 414 static int
 415 nouveau_svm_fault_cmp(const void *a, const void *b)
 416 {
 417         const struct nouveau_svm_fault *fa = *(struct nouveau_svm_fault **)a;
 418         const struct nouveau_svm_fault *fb = *(struct nouveau_svm_fault **)b;
 419         int ret;
 420         if ((ret = (s64)fa->inst - fb->inst))
 421                 return ret;
 422         if ((ret = (s64)fa->addr - fb->addr))
 423                 return ret;
 424         /*XXX: atomic? */
 425         return (fa->access == 0 || fa->access == 3) -
 426                (fb->access == 0 || fb->access == 3);
 427 }
 428
 429 static void
 430 nouveau_svm_fault_cache(struct nouveau_svm *svm,
 431                         struct nouveau_svm_fault_buffer *buffer, u32 offset)
 432 {
 433         struct nvif_object *memory = &buffer->object;
 434         const u32 instlo = nvif_rd32(memory, offset + 0x00);
 435         const u32 insthi = nvif_rd32(memory, offset + 0x04);
 436         const u32 addrlo = nvif_rd32(memory, offset + 0x08);
 437         const u32 addrhi = nvif_rd32(memory, offset + 0x0c);
 438         const u32 timelo = nvif_rd32(memory, offset + 0x10);
 439         const u32 timehi = nvif_rd32(memory, offset + 0x14);
 440         const u32 engine = nvif_rd32(memory, offset + 0x18);
 441         const u32   info = nvif_rd32(memory, offset + 0x1c);
 442         const u64   inst = (u64)insthi << 32 | instlo;
 443         const u8     gpc = (info & 0x1f000000) >> 24;
 444         const u8     hub = (info & 0x00100000) >> 20;
 445         const u8  client = (info & 0x00007f00) >> 8;
 446         struct nouveau_svm_fault *fault;
 447
 448         //XXX: i think we're supposed to spin waiting */
 449         if (WARN_ON(!(info & 0x80000000)))
 450                 return;
 451
 452         nvif_mask(memory, offset + 0x1c, 0x80000000, 0x00000000);
 453
 454         if (!buffer->fault[buffer->fault_nr]) {
 455                 fault = kmalloc(sizeof(*fault), GFP_KERNEL);
 456                 if (WARN_ON(!fault)) {
 457                         nouveau_svm_fault_cancel(svm, inst, hub, gpc, client);
 458                         return;
 459                 }
 460                 buffer->fault[buffer->fault_nr] = fault;
 461         }
 462
 463         fault = buffer->fault[buffer->fault_nr++];
 464         fault->inst   = inst;
 465         fault->addr   = (u64)addrhi << 32 | addrlo;
 466         fault->time   = (u64)timehi << 32 | timelo;
 467         fault->engine = engine;
 468         fault->gpc    = gpc;
 469         fault->hub    = hub;
 470         fault->access = (info & 0x000f0000) >> 16;
 471         fault->client = client;
 472         fault->fault  = (info & 0x0000001f);
 473
 474         SVM_DBG(svm, "fault %016llx %016llx %02x",
 475                 fault->inst, fault->addr, fault->access);
 476 }
 477
 478 struct svm_notifier {
 479         struct mmu_interval_notifier notifier;
 480         struct nouveau_svmm *svmm;
 481 };
 482
 483 static bool nouveau_svm_range_invalidate(struct mmu_interval_notifier *mni,
 484                                          const struct mmu_notifier_range *range,
 485                                          unsigned long cur_seq)
 486 {
 487         struct svm_notifier *sn =
 488                 container_of(mni, struct svm_notifier, notifier);
 489
 490         /*
 491          * serializes the update to mni->invalidate_seq done by caller and
 492          * prevents invalidation of the PTE from progressing while HW is being
 493          * programmed. This is very hacky and only works because the normal
 494          * notifier that does invalidation is always called after the range
 495          * notifier.
 496          */
 497         if (mmu_notifier_range_blockable(range))
 498                 mutex_lock(&sn->svmm->mutex);
 499         else if (!mutex_trylock(&sn->svmm->mutex))
 500                 return false;
 501         mmu_interval_set_seq(mni, cur_seq);
 502         mutex_unlock(&sn->svmm->mutex);
 503         return true;
 504 }
 505
 506 static const struct mmu_interval_notifier_ops nouveau_svm_mni_ops = {
 507         .invalidate = nouveau_svm_range_invalidate,
 508 };
 509
 510 static void nouveau_hmm_convert_pfn(struct nouveau_drm *drm,
 511                                     struct hmm_range *range,
 512                                     struct nouveau_pfnmap_args *args)
 513 {
 514         struct page *page;
 515
 516         /*
 517          * The address prepared here is passed through nvif_object_ioctl()
 518          * to an eventual DMA map in something like gp100_vmm_pgt_pfn()
 519          *
 520          * This is all just encoding the internal hmm representation into a
 521          * different nouveau internal representation.
 522          */
 523         if (!(range->hmm_pfns[0] & HMM_PFN_VALID)) {
 524                 args->p.phys[0] = 0;
 525                 return;
 526         }
 527
 528         page = hmm_pfn_to_page(range->hmm_pfns[0]);
 529         /*
 530          * Only map compound pages to the GPU if the CPU is also mapping the
 531          * page as a compound page. Otherwise, the PTE protections might not be
 532          * consistent (e.g., CPU only maps part of a compound page).
 533          * Note that the underlying page might still be larger than the
 534          * CPU mapping (e.g., a PUD sized compound page partially mapped with
 535          * a PMD sized page table entry).
 536          */
 537         if (hmm_pfn_to_map_order(range->hmm_pfns[0])) {
 538                 unsigned long addr = args->p.addr;
 539
 540                 args->p.page = hmm_pfn_to_map_order(range->hmm_pfns[0]) +
 541                                 PAGE_SHIFT;
 542                 args->p.size = 1UL << args->p.page;
 543                 args->p.addr &= ~(args->p.size - 1);
 544                 page -= (addr - args->p.addr) >> PAGE_SHIFT;
 545         }
 546         if (is_device_private_page(page))
 547                 args->p.phys[0] = nouveau_dmem_page_addr(page) |
 548                                 NVIF_VMM_PFNMAP_V0_V |
 549                                 NVIF_VMM_PFNMAP_V0_VRAM;
 550         else
 551                 args->p.phys[0] = page_to_phys(page) |
 552                                 NVIF_VMM_PFNMAP_V0_V |
 553                                 NVIF_VMM_PFNMAP_V0_HOST;
 554         if (range->hmm_pfns[0] & HMM_PFN_WRITE)
 555                 args->p.phys[0] |= NVIF_VMM_PFNMAP_V0_W;
 556 }
 557
 558 static int nouveau_range_fault(struct nouveau_svmm *svmm,
 559                                struct nouveau_drm *drm,
 560                                struct nouveau_pfnmap_args *args, u32 size,
 561                                unsigned long hmm_flags,
 562                                struct svm_notifier *notifier)
 563 {
 564         unsigned long timeout =
 565                 jiffies + msecs_to_jiffies(HMM_RANGE_DEFAULT_TIMEOUT);
 566         /* Have HMM fault pages within the fault window to the GPU. */
 567         unsigned long hmm_pfns[1];
 568         struct hmm_range range = {
 569                 .notifier = &notifier->notifier,
 570                 .start = notifier->notifier.interval_tree.start,
 571                 .end = notifier->notifier.interval_tree.last + 1,
 572                 .default_flags = hmm_flags,
 573                 .hmm_pfns = hmm_pfns,
 574                 .dev_private_owner = drm->dev,
 575         };
 576         struct mm_struct *mm = notifier->notifier.mm;
 577         int ret;
 578
 579         while (true) {
 580                 if (time_after(jiffies, timeout))
 581                         return -EBUSY;
 582
 583                 range.notifier_seq = mmu_interval_read_begin(range.notifier);
 584                 mmap_read_lock(mm);
 585                 ret = hmm_range_fault(&range);
 586                 mmap_read_unlock(mm);
 587                 if (ret) {
 588                         if (ret == -EBUSY)
 589                                 continue;
 590                         return ret;
 591                 }
 592
 593                 mutex_lock(&svmm->mutex);
 594                 if (mmu_interval_read_retry(range.notifier,
 595                                             range.notifier_seq)) {
 596                         mutex_unlock(&svmm->mutex);
 597                         continue;
 598                 }
 599                 break;
 600         }
 601
 602         nouveau_hmm_convert_pfn(drm, &range, args);
 603
 604         svmm->vmm->vmm.object.client->super = true;
 605         ret = nvif_object_ioctl(&svmm->vmm->vmm.object, args, size, NULL);
 606         svmm->vmm->vmm.object.client->super = false;
 607         mutex_unlock(&svmm->mutex);
 608
 609         return ret;
 610 }
 611
 612 static int
 613 nouveau_svm_fault(struct nvif_notify *notify)
 614 {
 615         struct nouveau_svm_fault_buffer *buffer =
 616                 container_of(notify, typeof(*buffer), notify);
 617         struct nouveau_svm *svm =
 618                 container_of(buffer, typeof(*svm), buffer[buffer->id]);
 619         struct nvif_object *device = &svm->drm->client.device.object;
 620         struct nouveau_svmm *svmm;
 621         struct {
 622                 struct nouveau_pfnmap_args i;
 623                 u64 phys[1];
 624         } args;
 625         unsigned long hmm_flags;
 626         u64 inst, start, limit;
 627         int fi, fn;
 628         int replay = 0, ret;
 629
 630         /* Parse available fault buffer entries into a cache, and update
 631          * the GET pointer so HW can reuse the entries.
 632          */
 633         SVM_DBG(svm, "fault handler");
 634         if (buffer->get == buffer->put) {
 635                 buffer->put = nvif_rd32(device, buffer->putaddr);
 636                 buffer->get = nvif_rd32(device, buffer->getaddr);
 637                 if (buffer->get == buffer->put)
 638                         return NVIF_NOTIFY_KEEP;
 639         }
 640         buffer->fault_nr = 0;
 641
 642         SVM_DBG(svm, "get %08x put %08x", buffer->get, buffer->put);
 643         while (buffer->get != buffer->put) {
 644                 nouveau_svm_fault_cache(svm, buffer, buffer->get * 0x20);
 645                 if (++buffer->get == buffer->entries)
 646                         buffer->get = 0;
 647         }
 648         nvif_wr32(device, buffer->getaddr, buffer->get);
 649         SVM_DBG(svm, "%d fault(s) pending", buffer->fault_nr);
 650
 651         /* Sort parsed faults by instance pointer to prevent unnecessary
 652          * instance to SVMM translations, followed by address and access
 653          * type to reduce the amount of work when handling the faults.
 654          */
 655         sort(buffer->fault, buffer->fault_nr, sizeof(*buffer->fault),
 656              nouveau_svm_fault_cmp, NULL);
 657
 658         /* Lookup SVMM structure for each unique instance pointer. */
 659         mutex_lock(&svm->mutex);
 660         for (fi = 0, svmm = NULL; fi < buffer->fault_nr; fi++) {
 661                 if (!svmm || buffer->fault[fi]->inst != inst) {
 662                         struct nouveau_ivmm *ivmm =
 663                                 nouveau_ivmm_find(svm, buffer->fault[fi]->inst);
 664                         svmm = ivmm ? ivmm->svmm : NULL;
 665                         inst = buffer->fault[fi]->inst;
 666                         SVM_DBG(svm, "inst %016llx -> svm-%p", inst, svmm);
 667                 }
 668                 buffer->fault[fi]->svmm = svmm;
 669         }
 670         mutex_unlock(&svm->mutex);
 671
 672         /* Process list of faults. */
 673         args.i.i.version = 0;
 674         args.i.i.type = NVIF_IOCTL_V0_MTHD;
 675         args.i.m.version = 0;
 676         args.i.m.method = NVIF_VMM_V0_PFNMAP;
 677         args.i.p.version = 0;
 678
 679         for (fi = 0; fn = fi + 1, fi < buffer->fault_nr; fi = fn) {
 680                 struct svm_notifier notifier;
 681                 struct mm_struct *mm;
 682
 683                 /* Cancel any faults from non-SVM channels. */
 684                 if (!(svmm = buffer->fault[fi]->svmm)) {
 685                         nouveau_svm_fault_cancel_fault(svm, buffer->fault[fi]);
 686                         continue;
 687                 }
 688                 SVMM_DBG(svmm, "addr %016llx", buffer->fault[fi]->addr);
 689
 690                 /* We try and group handling of faults within a small
 691                  * window into a single update.
 692                  */
 693                 start = buffer->fault[fi]->addr;
 694                 limit = start + PAGE_SIZE;
 695                 if (start < svmm->unmanaged.limit)
 696                         limit = min_t(u64, limit, svmm->unmanaged.start);
 697
 698                 /*
 699                  * Prepare the GPU-side update of all pages within the
 700                  * fault window, determining required pages and access
 701                  * permissions based on pending faults.
 702                  */
 703                 args.i.p.addr = start;
 704                 args.i.p.page = PAGE_SHIFT;
 705                 args.i.p.size = PAGE_SIZE;
 706                 /*
 707                  * Determine required permissions based on GPU fault
 708                  * access flags.
 709                  * XXX: atomic?
 710                  */
 711                 switch (buffer->fault[fi]->access) {
 712                 case 0: /* READ. */
 713                         hmm_flags = HMM_PFN_REQ_FAULT;
 714                         break;
 715                 case 3: /* PREFETCH. */
 716                         hmm_flags = 0;
 717                         break;
 718                 default:
 719                         hmm_flags = HMM_PFN_REQ_FAULT | HMM_PFN_REQ_WRITE;
 720                         break;
 721                 }
 722
 723                 mm = svmm->notifier.mm;
 724                 if (!mmget_not_zero(mm)) {
 725                         nouveau_svm_fault_cancel_fault(svm, buffer->fault[fi]);
 726                         continue;
 727                 }
 728
 729                 notifier.svmm = svmm;
 730                 ret = mmu_interval_notifier_insert(&notifier.notifier, mm,
 731                                                    args.i.p.addr, args.i.p.size,
 732                                                    &nouveau_svm_mni_ops);
 733                 if (!ret) {
 734                         ret = nouveau_range_fault(svmm, svm->drm, &args.i,
 735                                 sizeof(args), hmm_flags, &notifier);
 736                         mmu_interval_notifier_remove(&notifier.notifier);
 737                 }
 738                 mmput(mm);
 739
 740                 limit = args.i.p.addr + args.i.p.size;
 741                 for (fn = fi; ++fn < buffer->fault_nr; ) {
 742                         /* It's okay to skip over duplicate addresses from the
 743                          * same SVMM as faults are ordered by access type such
 744                          * that only the first one needs to be handled.
 745                          *
 746                          * ie. WRITE faults appear first, thus any handling of
 747                          * pending READ faults will already be satisfied.
 748                          * But if a large page is mapped, make sure subsequent
 749                          * fault addresses have sufficient access permission.
 750                          */
 751                         if (buffer->fault[fn]->svmm != svmm ||
 752                             buffer->fault[fn]->addr >= limit ||
 753                             (buffer->fault[fi]->access == 0 /* READ. */ &&
 754                              !(args.phys[0] & NVIF_VMM_PFNMAP_V0_V)) ||
 755                             (buffer->fault[fi]->access != 0 /* READ. */ &&
 756                              buffer->fault[fi]->access != 3 /* PREFETCH. */ &&
 757                              !(args.phys[0] & NVIF_VMM_PFNMAP_V0_W)))
 758                                 break;
 759                 }
 760
 761                 /* If handling failed completely, cancel all faults. */
 762                 if (ret) {
 763                         while (fi < fn) {
 764                                 struct nouveau_svm_fault *fault =
 765                                         buffer->fault[fi++];
 766
 767                                 nouveau_svm_fault_cancel_fault(svm, fault);
 768                         }
 769                 } else
 770                         replay++;
 771         }
 772
 773         /* Issue fault replay to the GPU. */
 774         if (replay)
 775                 nouveau_svm_fault_replay(svm);
 776         return NVIF_NOTIFY_KEEP;
 777 }
 778
 779 static struct nouveau_pfnmap_args *
 780 nouveau_pfns_to_args(void *pfns)
 781 {
 782         return container_of(pfns, struct nouveau_pfnmap_args, p.phys);
 783 }
 784
 785 u64 *
 786 nouveau_pfns_alloc(unsigned long npages)
 787 {
 788         struct nouveau_pfnmap_args *args;
 789
 790         args = kzalloc(struct_size(args, p.phys, npages), GFP_KERNEL);
 791         if (!args)
 792                 return NULL;
 793
 794         args->i.type = NVIF_IOCTL_V0_MTHD;
 795         args->m.method = NVIF_VMM_V0_PFNMAP;
 796         args->p.page = PAGE_SHIFT;
 797
 798         return args->p.phys;
 799 }
 800
 801 void
 802 nouveau_pfns_free(u64 *pfns)
 803 {
 804         struct nouveau_pfnmap_args *args = nouveau_pfns_to_args(pfns);
 805
 806         kfree(args);
 807 }
 808
 809 void
 810 nouveau_pfns_map(struct nouveau_svmm *svmm, struct mm_struct *mm,
 811                  unsigned long addr, u64 *pfns, unsigned long npages)
 812 {
 813         struct nouveau_pfnmap_args *args = nouveau_pfns_to_args(pfns);
 814         int ret;
 815
 816         args->p.addr = addr;
 817         args->p.size = npages << PAGE_SHIFT;
 818
 819         mutex_lock(&svmm->mutex);
 820
 821         svmm->vmm->vmm.object.client->super = true;
 822         ret = nvif_object_ioctl(&svmm->vmm->vmm.object, args, sizeof(*args) +
 823                                 npages * sizeof(args->p.phys[0]), NULL);
 824         svmm->vmm->vmm.object.client->super = false;
 825
 826         mutex_unlock(&svmm->mutex);
 827 }
 828
 829 static void
 830 nouveau_svm_fault_buffer_fini(struct nouveau_svm *svm, int id)
 831 {
 832         struct nouveau_svm_fault_buffer *buffer = &svm->buffer[id];
 833         nvif_notify_put(&buffer->notify);
 834 }
 835
 836 static int
 837 nouveau_svm_fault_buffer_init(struct nouveau_svm *svm, int id)
 838 {
 839         struct nouveau_svm_fault_buffer *buffer = &svm->buffer[id];
 840         struct nvif_object *device = &svm->drm->client.device.object;
 841         buffer->get = nvif_rd32(device, buffer->getaddr);
 842         buffer->put = nvif_rd32(device, buffer->putaddr);
 843         SVM_DBG(svm, "get %08x put %08x (init)", buffer->get, buffer->put);
 844         return nvif_notify_get(&buffer->notify);
 845 }
 846
 847 static void
 848 nouveau_svm_fault_buffer_dtor(struct nouveau_svm *svm, int id)
 849 {
 850         struct nouveau_svm_fault_buffer *buffer = &svm->buffer[id];
 851         int i;
 852
 853         if (buffer->fault) {
 854                 for (i = 0; buffer->fault[i] && i < buffer->entries; i++)
 855                         kfree(buffer->fault[i]);
 856                 kvfree(buffer->fault);
 857         }
 858
 859         nouveau_svm_fault_buffer_fini(svm, id);
 860
 861         nvif_notify_dtor(&buffer->notify);
 862         nvif_object_dtor(&buffer->object);
 863 }
 864
 865 static int
 866 nouveau_svm_fault_buffer_ctor(struct nouveau_svm *svm, s32 oclass, int id)
 867 {
 868         struct nouveau_svm_fault_buffer *buffer = &svm->buffer[id];
 869         struct nouveau_drm *drm = svm->drm;
 870         struct nvif_object *device = &drm->client.device.object;
 871         struct nvif_clb069_v0 args = {};
 872         int ret;
 873
 874         buffer->id = id;
 875
 876         ret = nvif_object_ctor(device, "svmFaultBuffer", 0, oclass, &args,
 877                                sizeof(args), &buffer->object);
 878         if (ret < 0) {
 879                 SVM_ERR(svm, "Fault buffer allocation failed: %d", ret);
 880                 return ret;
 881         }
 882
 883         nvif_object_map(&buffer->object, NULL, 0);
 884         buffer->entries = args.entries;
 885         buffer->getaddr = args.get;
 886         buffer->putaddr = args.put;
 887
 888         ret = nvif_notify_ctor(&buffer->object, "svmFault", nouveau_svm_fault,
 889                                true, NVB069_V0_NTFY_FAULT, NULL, 0, 0,
 890                                &buffer->notify);
 891         if (ret)
 892                 return ret;
 893
 894         buffer->fault = kvzalloc(sizeof(*buffer->fault) * buffer->entries, GFP_KERNEL);
 895         if (!buffer->fault)
 896                 return -ENOMEM;
 897
 898         return nouveau_svm_fault_buffer_init(svm, id);
 899 }
 900
 901 void
 902 nouveau_svm_resume(struct nouveau_drm *drm)
 903 {
 904         struct nouveau_svm *svm = drm->svm;
 905         if (svm)
 906                 nouveau_svm_fault_buffer_init(svm, 0);
 907 }
 908
 909 void
 910 nouveau_svm_suspend(struct nouveau_drm *drm)
 911 {
 912         struct nouveau_svm *svm = drm->svm;
 913         if (svm)
 914                 nouveau_svm_fault_buffer_fini(svm, 0);
 915 }
 916
 917 void
 918 nouveau_svm_fini(struct nouveau_drm *drm)
 919 {
 920         struct nouveau_svm *svm = drm->svm;
 921         if (svm) {
 922                 nouveau_svm_fault_buffer_dtor(svm, 0);
 923                 kfree(drm->svm);
 924                 drm->svm = NULL;
 925         }
 926 }
 927
 928 void
 929 nouveau_svm_init(struct nouveau_drm *drm)
 930 {
 931         static const struct nvif_mclass buffers[] = {
 932                 {   VOLTA_FAULT_BUFFER_A, 0 },
 933                 { MAXWELL_FAULT_BUFFER_A, 0 },
 934                 {}
 935         };
 936         struct nouveau_svm *svm;
 937         int ret;
 938
 939         /* Disable on Volta and newer until channel recovery is fixed,
 940          * otherwise clients will have a trivial way to trash the GPU
 941          * for everyone.
 942          */
 943         if (drm->client.device.info.family > NV_DEVICE_INFO_V0_PASCAL)
 944                 return;
 945
 946         if (!(drm->svm = svm = kzalloc(sizeof(*drm->svm), GFP_KERNEL)))
 947                 return;
 948
 949         drm->svm->drm = drm;
 950         mutex_init(&drm->svm->mutex);
 951         INIT_LIST_HEAD(&drm->svm->inst);
 952
 953         ret = nvif_mclass(&drm->client.device.object, buffers);
 954         if (ret < 0) {
 955                 SVM_DBG(svm, "No supported fault buffer class");
 956                 nouveau_svm_fini(drm);
 957                 return;
 958         }
 959
 960         ret = nouveau_svm_fault_buffer_ctor(svm, buffers[ret].oclass, 0);
 961         if (ret) {
 962                 nouveau_svm_fini(drm);
 963                 return;
 964         }
 965
 966         SVM_DBG(svm, "Initialised");
 967 }