drivers/gpu/drm/etnaviv/etnaviv_mmu.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (C) 2015-2018 Etnaviv Project
   4  */
   5
   6 #include <linux/dma-mapping.h>
   7 #include <linux/scatterlist.h>
   8
   9 #include "common.xml.h"
  10 #include "etnaviv_cmdbuf.h"
  11 #include "etnaviv_drv.h"
  12 #include "etnaviv_gem.h"
  13 #include "etnaviv_gpu.h"
  14 #include "etnaviv_mmu.h"
  15
  16 static void etnaviv_context_unmap(struct etnaviv_iommu_context *context,
  17                                  unsigned long iova, size_t size)
  18 {
  19         size_t unmapped_page, unmapped = 0;
  20         size_t pgsize = SZ_4K;
  21
  22         if (!IS_ALIGNED(iova | size, pgsize)) {
  23                 pr_err("unaligned: iova 0x%lx size 0x%zx min_pagesz 0x%zx\n",
  24                        iova, size, pgsize);
  25                 return;
  26         }
  27
  28         while (unmapped < size) {
  29                 unmapped_page = context->global->ops->unmap(context, iova,
  30                                                             pgsize);
  31                 if (!unmapped_page)
  32                         break;
  33
  34                 iova += unmapped_page;
  35                 unmapped += unmapped_page;
  36         }
  37 }
  38
  39 static int etnaviv_context_map(struct etnaviv_iommu_context *context,
  40                               unsigned long iova, phys_addr_t paddr,
  41                               size_t size, int prot)
  42 {
  43         unsigned long orig_iova = iova;
  44         size_t pgsize = SZ_4K;
  45         size_t orig_size = size;
  46         int ret = 0;
  47
  48         if (!IS_ALIGNED(iova | paddr | size, pgsize)) {
  49                 pr_err("unaligned: iova 0x%lx pa %pa size 0x%zx min_pagesz 0x%zx\n",
  50                        iova, &paddr, size, pgsize);
  51                 return -EINVAL;
  52         }
  53
  54         while (size) {
  55                 ret = context->global->ops->map(context, iova, paddr, pgsize,
  56                                                 prot);
  57                 if (ret)
  58                         break;
  59
  60                 iova += pgsize;
  61                 paddr += pgsize;
  62                 size -= pgsize;
  63         }
  64
  65         /* unroll mapping in case something went wrong */
  66         if (ret)
  67                 etnaviv_context_unmap(context, orig_iova, orig_size - size);
  68
  69         return ret;
  70 }
  71
  72 static int etnaviv_iommu_map(struct etnaviv_iommu_context *context, u32 iova,
  73                              struct sg_table *sgt, unsigned len, int prot)
  74 {       struct scatterlist *sg;
  75         unsigned int da = iova;
  76         unsigned int i;
  77         int ret;
  78
  79         if (!context || !sgt)
  80                 return -EINVAL;
  81
  82         for_each_sgtable_dma_sg(sgt, sg, i) {
  83                 phys_addr_t pa = sg_dma_address(sg) - sg->offset;
  84                 size_t bytes = sg_dma_len(sg) + sg->offset;
  85
  86                 VERB("map[%d]: %08x %pap(%zx)", i, iova, &pa, bytes);
  87
  88                 ret = etnaviv_context_map(context, da, pa, bytes, prot);
  89                 if (ret)
  90                         goto fail;
  91
  92                 da += bytes;
  93         }
  94
  95         context->flush_seq++;
  96
  97         return 0;
  98
  99 fail:
 100         etnaviv_context_unmap(context, iova, da - iova);
 101         return ret;
 102 }
 103
 104 static void etnaviv_iommu_unmap(struct etnaviv_iommu_context *context, u32 iova,
 105                                 struct sg_table *sgt, unsigned len)
 106 {
 107         struct scatterlist *sg;
 108         unsigned int da = iova;
 109         int i;
 110
 111         for_each_sgtable_dma_sg(sgt, sg, i) {
 112                 size_t bytes = sg_dma_len(sg) + sg->offset;
 113
 114                 etnaviv_context_unmap(context, da, bytes);
 115
 116                 VERB("unmap[%d]: %08x(%zx)", i, iova, bytes);
 117
 118                 BUG_ON(!PAGE_ALIGNED(bytes));
 119
 120                 da += bytes;
 121         }
 122
 123         context->flush_seq++;
 124 }
 125
 126 static void etnaviv_iommu_remove_mapping(struct etnaviv_iommu_context *context,
 127         struct etnaviv_vram_mapping *mapping)
 128 {
 129         struct etnaviv_gem_object *etnaviv_obj = mapping->object;
 130
 131         lockdep_assert_held(&context->lock);
 132
 133         etnaviv_iommu_unmap(context, mapping->vram_node.start,
 134                             etnaviv_obj->sgt, etnaviv_obj->base.size);
 135         drm_mm_remove_node(&mapping->vram_node);
 136 }
 137
 138 void etnaviv_iommu_reap_mapping(struct etnaviv_vram_mapping *mapping)
 139 {
 140         struct etnaviv_iommu_context *context = mapping->context;
 141
 142         lockdep_assert_held(&context->lock);
 143         WARN_ON(mapping->use);
 144
 145         etnaviv_iommu_remove_mapping(context, mapping);
 146         etnaviv_iommu_context_put(mapping->context);
 147         mapping->context = NULL;
 148         list_del_init(&mapping->mmu_node);
 149 }
 150
 151 static int etnaviv_iommu_find_iova(struct etnaviv_iommu_context *context,
 152                                    struct drm_mm_node *node, size_t size)
 153 {
 154         struct etnaviv_vram_mapping *free = NULL;
 155         enum drm_mm_insert_mode mode = DRM_MM_INSERT_LOW;
 156         int ret;
 157
 158         lockdep_assert_held(&context->lock);
 159
 160         while (1) {
 161                 struct etnaviv_vram_mapping *m, *n;
 162                 struct drm_mm_scan scan;
 163                 struct list_head list;
 164                 bool found;
 165
 166                 ret = drm_mm_insert_node_in_range(&context->mm, node,
 167                                                   size, 0, 0, 0, U64_MAX, mode);
 168                 if (ret != -ENOSPC)
 169                         break;
 170
 171                 /* Try to retire some entries */
 172                 drm_mm_scan_init(&scan, &context->mm, size, 0, 0, mode);
 173
 174                 found = 0;
 175                 INIT_LIST_HEAD(&list);
 176                 list_for_each_entry(free, &context->mappings, mmu_node) {
 177                         /* If this vram node has not been used, skip this. */
 178                         if (!free->vram_node.mm)
 179                                 continue;
 180
 181                         /*
 182                          * If the iova is pinned, then it's in-use,
 183                          * so we must keep its mapping.
 184                          */
 185                         if (free->use)
 186                                 continue;
 187
 188                         list_add(&free->scan_node, &list);
 189                         if (drm_mm_scan_add_block(&scan, &free->vram_node)) {
 190                                 found = true;
 191                                 break;
 192                         }
 193                 }
 194
 195                 if (!found) {
 196                         /* Nothing found, clean up and fail */
 197                         list_for_each_entry_safe(m, n, &list, scan_node)
 198                                 BUG_ON(drm_mm_scan_remove_block(&scan, &m->vram_node));
 199                         break;
 200                 }
 201
 202                 /*
 203                  * drm_mm does not allow any other operations while
 204                  * scanning, so we have to remove all blocks first.
 205                  * If drm_mm_scan_remove_block() returns false, we
 206                  * can leave the block pinned.
 207                  */
 208                 list_for_each_entry_safe(m, n, &list, scan_node)
 209                         if (!drm_mm_scan_remove_block(&scan, &m->vram_node))
 210                                 list_del_init(&m->scan_node);
 211
 212                 /*
 213                  * Unmap the blocks which need to be reaped from the MMU.
 214                  * Clear the mmu pointer to prevent the mapping_get finding
 215                  * this mapping.
 216                  */
 217                 list_for_each_entry_safe(m, n, &list, scan_node) {
 218                         etnaviv_iommu_reap_mapping(m);
 219                         list_del_init(&m->scan_node);
 220                 }
 221
 222                 mode = DRM_MM_INSERT_EVICT;
 223
 224                 /*
 225                  * We removed enough mappings so that the new allocation will
 226                  * succeed, retry the allocation one more time.
 227                  */
 228         }
 229
 230         return ret;
 231 }
 232
 233 static int etnaviv_iommu_insert_exact(struct etnaviv_iommu_context *context,
 234                    struct drm_mm_node *node, size_t size, u64 va)
 235 {
 236         struct etnaviv_vram_mapping *m, *n;
 237         struct drm_mm_node *scan_node;
 238         LIST_HEAD(scan_list);
 239         int ret;
 240
 241         lockdep_assert_held(&context->lock);
 242
 243         ret = drm_mm_insert_node_in_range(&context->mm, node, size, 0, 0, va,
 244                                           va + size, DRM_MM_INSERT_LOWEST);
 245         if (ret != -ENOSPC)
 246                 return ret;
 247
 248         /*
 249          * When we can't insert the node, due to a existing mapping blocking
 250          * the address space, there are two possible reasons:
 251          * 1. Userspace genuinely messed up and tried to reuse address space
 252          * before the last job using this VMA has finished executing.
 253          * 2. The existing buffer mappings are idle, but the buffers are not
 254          * destroyed yet (likely due to being referenced by another context) in
 255          * which case the mappings will not be cleaned up and we must reap them
 256          * here to make space for the new mapping.
 257          */
 258
 259         drm_mm_for_each_node_in_range(scan_node, &context->mm, va, va + size) {
 260                 m = container_of(scan_node, struct etnaviv_vram_mapping,
 261                                  vram_node);
 262
 263                 if (m->use)
 264                         return -ENOSPC;
 265
 266                 list_add(&m->scan_node, &scan_list);
 267         }
 268
 269         list_for_each_entry_safe(m, n, &scan_list, scan_node) {
 270                 etnaviv_iommu_reap_mapping(m);
 271                 list_del_init(&m->scan_node);
 272         }
 273
 274         return drm_mm_insert_node_in_range(&context->mm, node, size, 0, 0, va,
 275                                            va + size, DRM_MM_INSERT_LOWEST);
 276 }
 277
 278 int etnaviv_iommu_map_gem(struct etnaviv_iommu_context *context,
 279         struct etnaviv_gem_object *etnaviv_obj, u32 memory_base,
 280         struct etnaviv_vram_mapping *mapping, u64 va)
 281 {
 282         struct sg_table *sgt = etnaviv_obj->sgt;
 283         struct drm_mm_node *node;
 284         int ret;
 285
 286         lockdep_assert_held(&etnaviv_obj->lock);
 287
 288         mutex_lock(&context->lock);
 289
 290         /* v1 MMU can optimize single entry (contiguous) scatterlists */
 291         if (context->global->version == ETNAVIV_IOMMU_V1 &&
 292             sgt->nents == 1 && !(etnaviv_obj->flags & ETNA_BO_FORCE_MMU)) {
 293                 u32 iova;
 294
 295                 iova = sg_dma_address(sgt->sgl) - memory_base;
 296                 if (iova < 0x80000000 - sg_dma_len(sgt->sgl)) {
 297                         mapping->iova = iova;
 298                         mapping->context = etnaviv_iommu_context_get(context);
 299                         list_add_tail(&mapping->mmu_node, &context->mappings);
 300                         ret = 0;
 301                         goto unlock;
 302                 }
 303         }
 304
 305         node = &mapping->vram_node;
 306
 307         if (va)
 308                 ret = etnaviv_iommu_insert_exact(context, node,
 309                                                  etnaviv_obj->base.size, va);
 310         else
 311                 ret = etnaviv_iommu_find_iova(context, node,
 312                                               etnaviv_obj->base.size);
 313         if (ret < 0)
 314                 goto unlock;
 315
 316         mapping->iova = node->start;
 317         ret = etnaviv_iommu_map(context, node->start, sgt, etnaviv_obj->base.size,
 318                                 ETNAVIV_PROT_READ | ETNAVIV_PROT_WRITE);
 319
 320         if (ret < 0) {
 321                 drm_mm_remove_node(node);
 322                 goto unlock;
 323         }
 324
 325         mapping->context = etnaviv_iommu_context_get(context);
 326         list_add_tail(&mapping->mmu_node, &context->mappings);
 327 unlock:
 328         mutex_unlock(&context->lock);
 329
 330         return ret;
 331 }
 332
 333 void etnaviv_iommu_unmap_gem(struct etnaviv_iommu_context *context,
 334         struct etnaviv_vram_mapping *mapping)
 335 {
 336         WARN_ON(mapping->use);
 337
 338         mutex_lock(&context->lock);
 339
 340         /* Bail if the mapping has been reaped by another thread */
 341         if (!mapping->context) {
 342                 mutex_unlock(&context->lock);
 343                 return;
 344         }
 345
 346         /* If the vram node is on the mm, unmap and remove the node */
 347         if (mapping->vram_node.mm == &context->mm)
 348                 etnaviv_iommu_remove_mapping(context, mapping);
 349
 350         list_del(&mapping->mmu_node);
 351         mutex_unlock(&context->lock);
 352         etnaviv_iommu_context_put(context);
 353 }
 354
 355 static void etnaviv_iommu_context_free(struct kref *kref)
 356 {
 357         struct etnaviv_iommu_context *context =
 358                 container_of(kref, struct etnaviv_iommu_context, refcount);
 359
 360         etnaviv_cmdbuf_suballoc_unmap(context, &context->cmdbuf_mapping);
 361
 362         context->global->ops->free(context);
 363 }
 364 void etnaviv_iommu_context_put(struct etnaviv_iommu_context *context)
 365 {
 366         kref_put(&context->refcount, etnaviv_iommu_context_free);
 367 }
 368
 369 struct etnaviv_iommu_context *
 370 etnaviv_iommu_context_init(struct etnaviv_iommu_global *global,
 371                            struct etnaviv_cmdbuf_suballoc *suballoc)
 372 {
 373         struct etnaviv_iommu_context *ctx;
 374         int ret;
 375
 376         if (global->version == ETNAVIV_IOMMU_V1)
 377                 ctx = etnaviv_iommuv1_context_alloc(global);
 378         else
 379                 ctx = etnaviv_iommuv2_context_alloc(global);
 380
 381         if (!ctx)
 382                 return NULL;
 383
 384         ret = etnaviv_cmdbuf_suballoc_map(suballoc, ctx, &ctx->cmdbuf_mapping,
 385                                           global->memory_base);
 386         if (ret)
 387                 goto out_free;
 388
 389         if (global->version == ETNAVIV_IOMMU_V1 &&
 390             ctx->cmdbuf_mapping.iova > 0x80000000) {
 391                 dev_err(global->dev,
 392                         "command buffer outside valid memory window\n");
 393                 goto out_unmap;
 394         }
 395
 396         return ctx;
 397
 398 out_unmap:
 399         etnaviv_cmdbuf_suballoc_unmap(ctx, &ctx->cmdbuf_mapping);
 400 out_free:
 401         global->ops->free(ctx);
 402         return NULL;
 403 }
 404
 405 void etnaviv_iommu_restore(struct etnaviv_gpu *gpu,
 406                            struct etnaviv_iommu_context *context)
 407 {
 408         context->global->ops->restore(gpu, context);
 409 }
 410
 411 int etnaviv_iommu_get_suballoc_va(struct etnaviv_iommu_context *context,
 412                                   struct etnaviv_vram_mapping *mapping,
 413                                   u32 memory_base, dma_addr_t paddr,
 414                                   size_t size)
 415 {
 416         mutex_lock(&context->lock);
 417
 418         if (mapping->use > 0) {
 419                 mapping->use++;
 420                 mutex_unlock(&context->lock);
 421                 return 0;
 422         }
 423
 424         /*
 425          * For MMUv1 we don't add the suballoc region to the pagetables, as
 426          * those GPUs can only work with cmdbufs accessed through the linear
 427          * window. Instead we manufacture a mapping to make it look uniform
 428          * to the upper layers.
 429          */
 430         if (context->global->version == ETNAVIV_IOMMU_V1) {
 431                 mapping->iova = paddr - memory_base;
 432         } else {
 433                 struct drm_mm_node *node = &mapping->vram_node;
 434                 int ret;
 435
 436                 ret = etnaviv_iommu_find_iova(context, node, size);
 437                 if (ret < 0) {
 438                         mutex_unlock(&context->lock);
 439                         return ret;
 440                 }
 441
 442                 mapping->iova = node->start;
 443                 ret = etnaviv_context_map(context, node->start, paddr, size,
 444                                           ETNAVIV_PROT_READ);
 445                 if (ret < 0) {
 446                         drm_mm_remove_node(node);
 447                         mutex_unlock(&context->lock);
 448                         return ret;
 449                 }
 450
 451                 context->flush_seq++;
 452         }
 453
 454         list_add_tail(&mapping->mmu_node, &context->mappings);
 455         mapping->use = 1;
 456
 457         mutex_unlock(&context->lock);
 458
 459         return 0;
 460 }
 461
 462 void etnaviv_iommu_put_suballoc_va(struct etnaviv_iommu_context *context,
 463                   struct etnaviv_vram_mapping *mapping)
 464 {
 465         struct drm_mm_node *node = &mapping->vram_node;
 466
 467         mutex_lock(&context->lock);
 468         mapping->use--;
 469
 470         if (mapping->use > 0 || context->global->version == ETNAVIV_IOMMU_V1) {
 471                 mutex_unlock(&context->lock);
 472                 return;
 473         }
 474
 475         etnaviv_context_unmap(context, node->start, node->size);
 476         drm_mm_remove_node(node);
 477         mutex_unlock(&context->lock);
 478 }
 479
 480 size_t etnaviv_iommu_dump_size(struct etnaviv_iommu_context *context)
 481 {
 482         return context->global->ops->dump_size(context);
 483 }
 484
 485 void etnaviv_iommu_dump(struct etnaviv_iommu_context *context, void *buf)
 486 {
 487         context->global->ops->dump(context, buf);
 488 }
 489
 490 int etnaviv_iommu_global_init(struct etnaviv_gpu *gpu)
 491 {
 492         enum etnaviv_iommu_version version = ETNAVIV_IOMMU_V1;
 493         struct etnaviv_drm_private *priv = gpu->drm->dev_private;
 494         struct etnaviv_iommu_global *global;
 495         struct device *dev = gpu->drm->dev;
 496
 497         if (gpu->identity.minor_features1 & chipMinorFeatures1_MMU_VERSION)
 498                 version = ETNAVIV_IOMMU_V2;
 499
 500         if (priv->mmu_global) {
 501                 if (priv->mmu_global->version != version) {
 502                         dev_err(gpu->dev,
 503                                 "MMU version doesn't match global version\n");
 504                         return -ENXIO;
 505                 }
 506
 507                 priv->mmu_global->use++;
 508                 return 0;
 509         }
 510
 511         global = kzalloc(sizeof(*global), GFP_KERNEL);
 512         if (!global)
 513                 return -ENOMEM;
 514
 515         global->bad_page_cpu = dma_alloc_wc(dev, SZ_4K, &global->bad_page_dma,
 516                                             GFP_KERNEL);
 517         if (!global->bad_page_cpu)
 518                 goto free_global;
 519
 520         memset32(global->bad_page_cpu, 0xdead55aa, SZ_4K / sizeof(u32));
 521
 522         if (version == ETNAVIV_IOMMU_V2) {
 523                 global->v2.pta_cpu = dma_alloc_wc(dev, ETNAVIV_PTA_SIZE,
 524                                                &global->v2.pta_dma, GFP_KERNEL);
 525                 if (!global->v2.pta_cpu)
 526                         goto free_bad_page;
 527         }
 528
 529         global->dev = dev;
 530         global->version = version;
 531         global->use = 1;
 532         mutex_init(&global->lock);
 533
 534         if (version == ETNAVIV_IOMMU_V1)
 535                 global->ops = &etnaviv_iommuv1_ops;
 536         else
 537                 global->ops = &etnaviv_iommuv2_ops;
 538
 539         priv->mmu_global = global;
 540
 541         return 0;
 542
 543 free_bad_page:
 544         dma_free_wc(dev, SZ_4K, global->bad_page_cpu, global->bad_page_dma);
 545 free_global:
 546         kfree(global);
 547
 548         return -ENOMEM;
 549 }
 550
 551 void etnaviv_iommu_global_fini(struct etnaviv_gpu *gpu)
 552 {
 553         struct etnaviv_drm_private *priv = gpu->drm->dev_private;
 554         struct etnaviv_iommu_global *global = priv->mmu_global;
 555
 556         if (!global)
 557                 return;
 558
 559         if (--global->use > 0)
 560                 return;
 561
 562         if (global->v2.pta_cpu)
 563                 dma_free_wc(global->dev, ETNAVIV_PTA_SIZE,
 564                             global->v2.pta_cpu, global->v2.pta_dma);
 565
 566         if (global->bad_page_cpu)
 567                 dma_free_wc(global->dev, SZ_4K,
 568                             global->bad_page_cpu, global->bad_page_dma);
 569
 570         mutex_destroy(&global->lock);
 571         kfree(global);
 572
 573         priv->mmu_global = NULL;
 574 }