drivers/gpu/drm/vc4/vc4_bo.c

   1 /*
   2  *  Copyright © 2015 Broadcom
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License version 2 as
   6  * published by the Free Software Foundation.
   7  */
   8
   9 /* DOC: VC4 GEM BO management support.
  10  *
  11  * The VC4 GPU architecture (both scanout and rendering) has direct
  12  * access to system memory with no MMU in between.  To support it, we
  13  * use the GEM CMA helper functions to allocate contiguous ranges of
  14  * physical memory for our BOs.
  15  *
  16  * Since the CMA allocator is very slow, we keep a cache of recently
  17  * freed BOs around so that the kernel's allocation of objects for 3D
  18  * rendering can return quickly.
  19  */
  20
  21 #include "vc4_drv.h"
  22 #include "uapi/drm/vc4_drm.h"
  23
  24 static void vc4_bo_stats_dump(struct vc4_dev *vc4)
  25 {
  26         DRM_INFO("num bos allocated: %d\n",
  27                  vc4->bo_stats.num_allocated);
  28         DRM_INFO("size bos allocated: %dkb\n",
  29                  vc4->bo_stats.size_allocated / 1024);
  30         DRM_INFO("num bos used: %d\n",
  31                  vc4->bo_stats.num_allocated - vc4->bo_stats.num_cached);
  32         DRM_INFO("size bos used: %dkb\n",
  33                  (vc4->bo_stats.size_allocated -
  34                   vc4->bo_stats.size_cached) / 1024);
  35         DRM_INFO("num bos cached: %d\n",
  36                  vc4->bo_stats.num_cached);
  37         DRM_INFO("size bos cached: %dkb\n",
  38                  vc4->bo_stats.size_cached / 1024);
  39 }
  40
  41 #ifdef CONFIG_DEBUG_FS
  42 int vc4_bo_stats_debugfs(struct seq_file *m, void *unused)
  43 {
  44         struct drm_info_node *node = (struct drm_info_node *)m->private;
  45         struct drm_device *dev = node->minor->dev;
  46         struct vc4_dev *vc4 = to_vc4_dev(dev);
  47         struct vc4_bo_stats stats;
  48
  49         /* Take a snapshot of the current stats with the lock held. */
  50         mutex_lock(&vc4->bo_lock);
  51         stats = vc4->bo_stats;
  52         mutex_unlock(&vc4->bo_lock);
  53
  54         seq_printf(m, "num bos allocated: %d\n",
  55                    stats.num_allocated);
  56         seq_printf(m, "size bos allocated: %dkb\n",
  57                    stats.size_allocated / 1024);
  58         seq_printf(m, "num bos used: %d\n",
  59                    stats.num_allocated - stats.num_cached);
  60         seq_printf(m, "size bos used: %dkb\n",
  61                    (stats.size_allocated - stats.size_cached) / 1024);
  62         seq_printf(m, "num bos cached: %d\n",
  63                    stats.num_cached);
  64         seq_printf(m, "size bos cached: %dkb\n",
  65                    stats.size_cached / 1024);
  66
  67         return 0;
  68 }
  69 #endif
  70
  71 static uint32_t bo_page_index(size_t size)
  72 {
  73         return (size / PAGE_SIZE) - 1;
  74 }
  75
  76 /* Must be called with bo_lock held. */
  77 static void vc4_bo_destroy(struct vc4_bo *bo)
  78 {
  79         struct drm_gem_object *obj = &bo->base.base;
  80         struct vc4_dev *vc4 = to_vc4_dev(obj->dev);
  81
  82         if (bo->validated_shader) {
  83                 kfree(bo->validated_shader->texture_samples);
  84                 kfree(bo->validated_shader);
  85                 bo->validated_shader = NULL;
  86         }
  87
  88         vc4->bo_stats.num_allocated--;
  89         vc4->bo_stats.size_allocated -= obj->size;
  90         drm_gem_cma_free_object(obj);
  91 }
  92
  93 /* Must be called with bo_lock held. */
  94 static void vc4_bo_remove_from_cache(struct vc4_bo *bo)
  95 {
  96         struct drm_gem_object *obj = &bo->base.base;
  97         struct vc4_dev *vc4 = to_vc4_dev(obj->dev);
  98
  99         vc4->bo_stats.num_cached--;
 100         vc4->bo_stats.size_cached -= obj->size;
 101
 102         list_del(&bo->unref_head);
 103         list_del(&bo->size_head);
 104 }
 105
 106 static struct list_head *vc4_get_cache_list_for_size(struct drm_device *dev,
 107                                                      size_t size)
 108 {
 109         struct vc4_dev *vc4 = to_vc4_dev(dev);
 110         uint32_t page_index = bo_page_index(size);
 111
 112         if (vc4->bo_cache.size_list_size <= page_index) {
 113                 uint32_t new_size = max(vc4->bo_cache.size_list_size * 2,
 114                                         page_index + 1);
 115                 struct list_head *new_list;
 116                 uint32_t i;
 117
 118                 new_list = kmalloc_array(new_size, sizeof(struct list_head),
 119                                          GFP_KERNEL);
 120                 if (!new_list)
 121                         return NULL;
 122
 123                 /* Rebase the old cached BO lists to their new list
 124                  * head locations.
 125                  */
 126                 for (i = 0; i < vc4->bo_cache.size_list_size; i++) {
 127                         struct list_head *old_list =
 128                                 &vc4->bo_cache.size_list[i];
 129
 130                         if (list_empty(old_list))
 131                                 INIT_LIST_HEAD(&new_list[i]);
 132                         else
 133                                 list_replace(old_list, &new_list[i]);
 134                 }
 135                 /* And initialize the brand new BO list heads. */
 136                 for (i = vc4->bo_cache.size_list_size; i < new_size; i++)
 137                         INIT_LIST_HEAD(&new_list[i]);
 138
 139                 kfree(vc4->bo_cache.size_list);
 140                 vc4->bo_cache.size_list = new_list;
 141                 vc4->bo_cache.size_list_size = new_size;
 142         }
 143
 144         return &vc4->bo_cache.size_list[page_index];
 145 }
 146
 147 void vc4_bo_cache_purge(struct drm_device *dev)
 148 {
 149         struct vc4_dev *vc4 = to_vc4_dev(dev);
 150
 151         mutex_lock(&vc4->bo_lock);
 152         while (!list_empty(&vc4->bo_cache.time_list)) {
 153                 struct vc4_bo *bo = list_last_entry(&vc4->bo_cache.time_list,
 154                                                     struct vc4_bo, unref_head);
 155                 vc4_bo_remove_from_cache(bo);
 156                 vc4_bo_destroy(bo);
 157         }
 158         mutex_unlock(&vc4->bo_lock);
 159 }
 160
 161 static struct vc4_bo *vc4_bo_get_from_cache(struct drm_device *dev,
 162                                             uint32_t size)
 163 {
 164         struct vc4_dev *vc4 = to_vc4_dev(dev);
 165         uint32_t page_index = bo_page_index(size);
 166         struct vc4_bo *bo = NULL;
 167
 168         size = roundup(size, PAGE_SIZE);
 169
 170         mutex_lock(&vc4->bo_lock);
 171         if (page_index >= vc4->bo_cache.size_list_size)
 172                 goto out;
 173
 174         if (list_empty(&vc4->bo_cache.size_list[page_index]))
 175                 goto out;
 176
 177         bo = list_first_entry(&vc4->bo_cache.size_list[page_index],
 178                               struct vc4_bo, size_head);
 179         vc4_bo_remove_from_cache(bo);
 180         kref_init(&bo->base.base.refcount);
 181
 182 out:
 183         mutex_unlock(&vc4->bo_lock);
 184         return bo;
 185 }
 186
 187 /**
 188  * vc4_gem_create_object - Implementation of driver->gem_create_object.
 189  *
 190  * This lets the CMA helpers allocate object structs for us, and keep
 191  * our BO stats correct.
 192  */
 193 struct drm_gem_object *vc4_create_object(struct drm_device *dev, size_t size)
 194 {
 195         struct vc4_dev *vc4 = to_vc4_dev(dev);
 196         struct vc4_bo *bo;
 197
 198         bo = kzalloc(sizeof(*bo), GFP_KERNEL);
 199         if (!bo)
 200                 return ERR_PTR(-ENOMEM);
 201
 202         mutex_lock(&vc4->bo_lock);
 203         vc4->bo_stats.num_allocated++;
 204         vc4->bo_stats.size_allocated += size;
 205         mutex_unlock(&vc4->bo_lock);
 206
 207         return &bo->base.base;
 208 }
 209
 210 struct vc4_bo *vc4_bo_create(struct drm_device *dev, size_t unaligned_size,
 211                              bool from_cache)
 212 {
 213         size_t size = roundup(unaligned_size, PAGE_SIZE);
 214         struct vc4_dev *vc4 = to_vc4_dev(dev);
 215         struct drm_gem_cma_object *cma_obj;
 216
 217         if (size == 0)
 218                 return ERR_PTR(-EINVAL);
 219
 220         /* First, try to get a vc4_bo from the kernel BO cache. */
 221         if (from_cache) {
 222                 struct vc4_bo *bo = vc4_bo_get_from_cache(dev, size);
 223
 224                 if (bo)
 225                         return bo;
 226         }
 227
 228         cma_obj = drm_gem_cma_create(dev, size);
 229         if (IS_ERR(cma_obj)) {
 230                 /*
 231                  * If we've run out of CMA memory, kill the cache of
 232                  * CMA allocations we've got laying around and try again.
 233                  */
 234                 vc4_bo_cache_purge(dev);
 235
 236                 cma_obj = drm_gem_cma_create(dev, size);
 237                 if (IS_ERR(cma_obj)) {
 238                         DRM_ERROR("Failed to allocate from CMA:\n");
 239                         vc4_bo_stats_dump(vc4);
 240                         return ERR_PTR(-ENOMEM);
 241                 }
 242         }
 243
 244         return to_vc4_bo(&cma_obj->base);
 245 }
 246
 247 int vc4_dumb_create(struct drm_file *file_priv,
 248                     struct drm_device *dev,
 249                     struct drm_mode_create_dumb *args)
 250 {
 251         int min_pitch = DIV_ROUND_UP(args->width * args->bpp, 8);
 252         struct vc4_bo *bo = NULL;
 253         int ret;
 254
 255         if (args->pitch < min_pitch)
 256                 args->pitch = min_pitch;
 257
 258         if (args->size < args->pitch * args->height)
 259                 args->size = args->pitch * args->height;
 260
 261         bo = vc4_bo_create(dev, args->size, false);
 262         if (IS_ERR(bo))
 263                 return PTR_ERR(bo);
 264
 265         ret = drm_gem_handle_create(file_priv, &bo->base.base, &args->handle);
 266         drm_gem_object_unreference_unlocked(&bo->base.base);
 267
 268         return ret;
 269 }
 270
 271 /* Must be called with bo_lock held. */
 272 static void vc4_bo_cache_free_old(struct drm_device *dev)
 273 {
 274         struct vc4_dev *vc4 = to_vc4_dev(dev);
 275         unsigned long expire_time = jiffies - msecs_to_jiffies(1000);
 276
 277         while (!list_empty(&vc4->bo_cache.time_list)) {
 278                 struct vc4_bo *bo = list_last_entry(&vc4->bo_cache.time_list,
 279                                                     struct vc4_bo, unref_head);
 280                 if (time_before(expire_time, bo->free_time)) {
 281                         mod_timer(&vc4->bo_cache.time_timer,
 282                                   round_jiffies_up(jiffies +
 283                                                    msecs_to_jiffies(1000)));
 284                         return;
 285                 }
 286
 287                 vc4_bo_remove_from_cache(bo);
 288                 vc4_bo_destroy(bo);
 289         }
 290 }
 291
 292 /* Called on the last userspace/kernel unreference of the BO.  Returns
 293  * it to the BO cache if possible, otherwise frees it.
 294  *
 295  * Note that this is called with the struct_mutex held.
 296  */
 297 void vc4_free_object(struct drm_gem_object *gem_bo)
 298 {
 299         struct drm_device *dev = gem_bo->dev;
 300         struct vc4_dev *vc4 = to_vc4_dev(dev);
 301         struct vc4_bo *bo = to_vc4_bo(gem_bo);
 302         struct list_head *cache_list;
 303
 304         mutex_lock(&vc4->bo_lock);
 305         /* If the object references someone else's memory, we can't cache it.
 306          */
 307         if (gem_bo->import_attach) {
 308                 vc4_bo_destroy(bo);
 309                 goto out;
 310         }
 311
 312         /* Don't cache if it was publicly named. */
 313         if (gem_bo->name) {
 314                 vc4_bo_destroy(bo);
 315                 goto out;
 316         }
 317
 318         cache_list = vc4_get_cache_list_for_size(dev, gem_bo->size);
 319         if (!cache_list) {
 320                 vc4_bo_destroy(bo);
 321                 goto out;
 322         }
 323
 324         if (bo->validated_shader) {
 325                 kfree(bo->validated_shader->texture_samples);
 326                 kfree(bo->validated_shader);
 327                 bo->validated_shader = NULL;
 328         }
 329
 330         bo->free_time = jiffies;
 331         list_add(&bo->size_head, cache_list);
 332         list_add(&bo->unref_head, &vc4->bo_cache.time_list);
 333
 334         vc4->bo_stats.num_cached++;
 335         vc4->bo_stats.size_cached += gem_bo->size;
 336
 337         vc4_bo_cache_free_old(dev);
 338
 339 out:
 340         mutex_unlock(&vc4->bo_lock);
 341 }
 342
 343 static void vc4_bo_cache_time_work(struct work_struct *work)
 344 {
 345         struct vc4_dev *vc4 =
 346                 container_of(work, struct vc4_dev, bo_cache.time_work);
 347         struct drm_device *dev = vc4->dev;
 348
 349         mutex_lock(&vc4->bo_lock);
 350         vc4_bo_cache_free_old(dev);
 351         mutex_unlock(&vc4->bo_lock);
 352 }
 353
 354 static void vc4_bo_cache_time_timer(unsigned long data)
 355 {
 356         struct drm_device *dev = (struct drm_device *)data;
 357         struct vc4_dev *vc4 = to_vc4_dev(dev);
 358
 359         schedule_work(&vc4->bo_cache.time_work);
 360 }
 361
 362 struct dma_buf *
 363 vc4_prime_export(struct drm_device *dev, struct drm_gem_object *obj, int flags)
 364 {
 365         struct vc4_bo *bo = to_vc4_bo(obj);
 366
 367         if (bo->validated_shader) {
 368                 DRM_ERROR("Attempting to export shader BO\n");
 369                 return ERR_PTR(-EINVAL);
 370         }
 371
 372         return drm_gem_prime_export(dev, obj, flags);
 373 }
 374
 375 int vc4_mmap(struct file *filp, struct vm_area_struct *vma)
 376 {
 377         struct drm_gem_object *gem_obj;
 378         struct vc4_bo *bo;
 379         int ret;
 380
 381         ret = drm_gem_mmap(filp, vma);
 382         if (ret)
 383                 return ret;
 384
 385         gem_obj = vma->vm_private_data;
 386         bo = to_vc4_bo(gem_obj);
 387
 388         if (bo->validated_shader && (vma->vm_flags & VM_WRITE)) {
 389                 DRM_ERROR("mmaping of shader BOs for writing not allowed.\n");
 390                 return -EINVAL;
 391         }
 392
 393         /*
 394          * Clear the VM_PFNMAP flag that was set by drm_gem_mmap(), and set the
 395          * vm_pgoff (used as a fake buffer offset by DRM) to 0 as we want to map
 396          * the whole buffer.
 397          */
 398         vma->vm_flags &= ~VM_PFNMAP;
 399         vma->vm_pgoff = 0;
 400
 401         ret = dma_mmap_wc(bo->base.base.dev->dev, vma, bo->base.vaddr,
 402                           bo->base.paddr, vma->vm_end - vma->vm_start);
 403         if (ret)
 404                 drm_gem_vm_close(vma);
 405
 406         return ret;
 407 }
 408
 409 int vc4_prime_mmap(struct drm_gem_object *obj, struct vm_area_struct *vma)
 410 {
 411         struct vc4_bo *bo = to_vc4_bo(obj);
 412
 413         if (bo->validated_shader && (vma->vm_flags & VM_WRITE)) {
 414                 DRM_ERROR("mmaping of shader BOs for writing not allowed.\n");
 415                 return -EINVAL;
 416         }
 417
 418         return drm_gem_cma_prime_mmap(obj, vma);
 419 }
 420
 421 void *vc4_prime_vmap(struct drm_gem_object *obj)
 422 {
 423         struct vc4_bo *bo = to_vc4_bo(obj);
 424
 425         if (bo->validated_shader) {
 426                 DRM_ERROR("mmaping of shader BOs not allowed.\n");
 427                 return ERR_PTR(-EINVAL);
 428         }
 429
 430         return drm_gem_cma_prime_vmap(obj);
 431 }
 432
 433 int vc4_create_bo_ioctl(struct drm_device *dev, void *data,
 434                         struct drm_file *file_priv)
 435 {
 436         struct drm_vc4_create_bo *args = data;
 437         struct vc4_bo *bo = NULL;
 438         int ret;
 439
 440         /*
 441          * We can't allocate from the BO cache, because the BOs don't
 442          * get zeroed, and that might leak data between users.
 443          */
 444         bo = vc4_bo_create(dev, args->size, false);
 445         if (IS_ERR(bo))
 446                 return PTR_ERR(bo);
 447
 448         ret = drm_gem_handle_create(file_priv, &bo->base.base, &args->handle);
 449         drm_gem_object_unreference_unlocked(&bo->base.base);
 450
 451         return ret;
 452 }
 453
 454 int vc4_mmap_bo_ioctl(struct drm_device *dev, void *data,
 455                       struct drm_file *file_priv)
 456 {
 457         struct drm_vc4_mmap_bo *args = data;
 458         struct drm_gem_object *gem_obj;
 459
 460         gem_obj = drm_gem_object_lookup(dev, file_priv, args->handle);
 461         if (!gem_obj) {
 462                 DRM_ERROR("Failed to look up GEM BO %d\n", args->handle);
 463                 return -EINVAL;
 464         }
 465
 466         /* The mmap offset was set up at BO allocation time. */
 467         args->offset = drm_vma_node_offset_addr(&gem_obj->vma_node);
 468
 469         drm_gem_object_unreference_unlocked(gem_obj);
 470         return 0;
 471 }
 472
 473 int
 474 vc4_create_shader_bo_ioctl(struct drm_device *dev, void *data,
 475                            struct drm_file *file_priv)
 476 {
 477         struct drm_vc4_create_shader_bo *args = data;
 478         struct vc4_bo *bo = NULL;
 479         int ret;
 480
 481         if (args->size == 0)
 482                 return -EINVAL;
 483
 484         if (args->size % sizeof(u64) != 0)
 485                 return -EINVAL;
 486
 487         if (args->flags != 0) {
 488                 DRM_INFO("Unknown flags set: 0x%08x\n", args->flags);
 489                 return -EINVAL;
 490         }
 491
 492         if (args->pad != 0) {
 493                 DRM_INFO("Pad set: 0x%08x\n", args->pad);
 494                 return -EINVAL;
 495         }
 496
 497         bo = vc4_bo_create(dev, args->size, true);
 498         if (IS_ERR(bo))
 499                 return PTR_ERR(bo);
 500
 501         if (copy_from_user(bo->base.vaddr,
 502                              (void __user *)(uintptr_t)args->data,
 503                              args->size)) {
 504                 ret = -EFAULT;
 505                 goto fail;
 506         }
 507         /* Clear the rest of the memory from allocating from the BO
 508          * cache.
 509          */
 510         memset(bo->base.vaddr + args->size, 0,
 511                bo->base.base.size - args->size);
 512
 513         bo->validated_shader = vc4_validate_shader(&bo->base);
 514         if (!bo->validated_shader) {
 515                 ret = -EINVAL;
 516                 goto fail;
 517         }
 518
 519         /* We have to create the handle after validation, to avoid
 520          * races for users to do doing things like mmap the shader BO.
 521          */
 522         ret = drm_gem_handle_create(file_priv, &bo->base.base, &args->handle);
 523
 524  fail:
 525         drm_gem_object_unreference_unlocked(&bo->base.base);
 526
 527         return ret;
 528 }
 529
 530 void vc4_bo_cache_init(struct drm_device *dev)
 531 {
 532         struct vc4_dev *vc4 = to_vc4_dev(dev);
 533
 534         mutex_init(&vc4->bo_lock);
 535
 536         INIT_LIST_HEAD(&vc4->bo_cache.time_list);
 537
 538         INIT_WORK(&vc4->bo_cache.time_work, vc4_bo_cache_time_work);
 539         setup_timer(&vc4->bo_cache.time_timer,
 540                     vc4_bo_cache_time_timer,
 541                     (unsigned long)dev);
 542 }
 543
 544 void vc4_bo_cache_destroy(struct drm_device *dev)
 545 {
 546         struct vc4_dev *vc4 = to_vc4_dev(dev);
 547
 548         del_timer(&vc4->bo_cache.time_timer);
 549         cancel_work_sync(&vc4->bo_cache.time_work);
 550
 551         vc4_bo_cache_purge(dev);
 552
 553         if (vc4->bo_stats.num_allocated) {
 554                 DRM_ERROR("Destroying BO cache while BOs still allocated:\n");
 555                 vc4_bo_stats_dump(vc4);
 556         }
 557 }