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