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 static 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 void vc4_free_object(struct drm_gem_object *gem_bo)
 296 {
 297         struct drm_device *dev = gem_bo->dev;
 298         struct vc4_dev *vc4 = to_vc4_dev(dev);
 299         struct vc4_bo *bo = to_vc4_bo(gem_bo);
 300         struct list_head *cache_list;
 301
 302         mutex_lock(&vc4->bo_lock);
 303         /* If the object references someone else's memory, we can't cache it.
 304          */
 305         if (gem_bo->import_attach) {
 306                 vc4_bo_destroy(bo);
 307                 goto out;
 308         }
 309
 310         /* Don't cache if it was publicly named. */
 311         if (gem_bo->name) {
 312                 vc4_bo_destroy(bo);
 313                 goto out;
 314         }
 315
 316         cache_list = vc4_get_cache_list_for_size(dev, gem_bo->size);
 317         if (!cache_list) {
 318                 vc4_bo_destroy(bo);
 319                 goto out;
 320         }
 321
 322         if (bo->validated_shader) {
 323                 kfree(bo->validated_shader->texture_samples);
 324                 kfree(bo->validated_shader);
 325                 bo->validated_shader = NULL;
 326         }
 327
 328         bo->free_time = jiffies;
 329         list_add(&bo->size_head, cache_list);
 330         list_add(&bo->unref_head, &vc4->bo_cache.time_list);
 331
 332         vc4->bo_stats.num_cached++;
 333         vc4->bo_stats.size_cached += gem_bo->size;
 334
 335         vc4_bo_cache_free_old(dev);
 336
 337 out:
 338         mutex_unlock(&vc4->bo_lock);
 339 }
 340
 341 static void vc4_bo_cache_time_work(struct work_struct *work)
 342 {
 343         struct vc4_dev *vc4 =
 344                 container_of(work, struct vc4_dev, bo_cache.time_work);
 345         struct drm_device *dev = vc4->dev;
 346
 347         mutex_lock(&vc4->bo_lock);
 348         vc4_bo_cache_free_old(dev);
 349         mutex_unlock(&vc4->bo_lock);
 350 }
 351
 352 static void vc4_bo_cache_time_timer(unsigned long data)
 353 {
 354         struct drm_device *dev = (struct drm_device *)data;
 355         struct vc4_dev *vc4 = to_vc4_dev(dev);
 356
 357         schedule_work(&vc4->bo_cache.time_work);
 358 }
 359
 360 struct dma_buf *
 361 vc4_prime_export(struct drm_device *dev, struct drm_gem_object *obj, int flags)
 362 {
 363         struct vc4_bo *bo = to_vc4_bo(obj);
 364
 365         if (bo->validated_shader) {
 366                 DRM_ERROR("Attempting to export shader BO\n");
 367                 return ERR_PTR(-EINVAL);
 368         }
 369
 370         return drm_gem_prime_export(dev, obj, flags);
 371 }
 372
 373 int vc4_mmap(struct file *filp, struct vm_area_struct *vma)
 374 {
 375         struct drm_gem_object *gem_obj;
 376         struct vc4_bo *bo;
 377         int ret;
 378
 379         ret = drm_gem_mmap(filp, vma);
 380         if (ret)
 381                 return ret;
 382
 383         gem_obj = vma->vm_private_data;
 384         bo = to_vc4_bo(gem_obj);
 385
 386         if (bo->validated_shader && (vma->vm_flags & VM_WRITE)) {
 387                 DRM_ERROR("mmaping of shader BOs for writing not allowed.\n");
 388                 return -EINVAL;
 389         }
 390
 391         /*
 392          * Clear the VM_PFNMAP flag that was set by drm_gem_mmap(), and set the
 393          * vm_pgoff (used as a fake buffer offset by DRM) to 0 as we want to map
 394          * the whole buffer.
 395          */
 396         vma->vm_flags &= ~VM_PFNMAP;
 397         vma->vm_pgoff = 0;
 398
 399         ret = dma_mmap_wc(bo->base.base.dev->dev, vma, bo->base.vaddr,
 400                           bo->base.paddr, vma->vm_end - vma->vm_start);
 401         if (ret)
 402                 drm_gem_vm_close(vma);
 403
 404         return ret;
 405 }
 406
 407 int vc4_prime_mmap(struct drm_gem_object *obj, struct vm_area_struct *vma)
 408 {
 409         struct vc4_bo *bo = to_vc4_bo(obj);
 410
 411         if (bo->validated_shader && (vma->vm_flags & VM_WRITE)) {
 412                 DRM_ERROR("mmaping of shader BOs for writing not allowed.\n");
 413                 return -EINVAL;
 414         }
 415
 416         return drm_gem_cma_prime_mmap(obj, vma);
 417 }
 418
 419 void *vc4_prime_vmap(struct drm_gem_object *obj)
 420 {
 421         struct vc4_bo *bo = to_vc4_bo(obj);
 422
 423         if (bo->validated_shader) {
 424                 DRM_ERROR("mmaping of shader BOs not allowed.\n");
 425                 return ERR_PTR(-EINVAL);
 426         }
 427
 428         return drm_gem_cma_prime_vmap(obj);
 429 }
 430
 431 int vc4_create_bo_ioctl(struct drm_device *dev, void *data,
 432                         struct drm_file *file_priv)
 433 {
 434         struct drm_vc4_create_bo *args = data;
 435         struct vc4_bo *bo = NULL;
 436         int ret;
 437
 438         /*
 439          * We can't allocate from the BO cache, because the BOs don't
 440          * get zeroed, and that might leak data between users.
 441          */
 442         bo = vc4_bo_create(dev, args->size, false);
 443         if (IS_ERR(bo))
 444                 return PTR_ERR(bo);
 445
 446         ret = drm_gem_handle_create(file_priv, &bo->base.base, &args->handle);
 447         drm_gem_object_unreference_unlocked(&bo->base.base);
 448
 449         return ret;
 450 }
 451
 452 int vc4_mmap_bo_ioctl(struct drm_device *dev, void *data,
 453                       struct drm_file *file_priv)
 454 {
 455         struct drm_vc4_mmap_bo *args = data;
 456         struct drm_gem_object *gem_obj;
 457
 458         gem_obj = drm_gem_object_lookup(file_priv, args->handle);
 459         if (!gem_obj) {
 460                 DRM_ERROR("Failed to look up GEM BO %d\n", args->handle);
 461                 return -EINVAL;
 462         }
 463
 464         /* The mmap offset was set up at BO allocation time. */
 465         args->offset = drm_vma_node_offset_addr(&gem_obj->vma_node);
 466
 467         drm_gem_object_unreference_unlocked(gem_obj);
 468         return 0;
 469 }
 470
 471 int
 472 vc4_create_shader_bo_ioctl(struct drm_device *dev, void *data,
 473                            struct drm_file *file_priv)
 474 {
 475         struct drm_vc4_create_shader_bo *args = data;
 476         struct vc4_bo *bo = NULL;
 477         int ret;
 478
 479         if (args->size == 0)
 480                 return -EINVAL;
 481
 482         if (args->size % sizeof(u64) != 0)
 483                 return -EINVAL;
 484
 485         if (args->flags != 0) {
 486                 DRM_INFO("Unknown flags set: 0x%08x\n", args->flags);
 487                 return -EINVAL;
 488         }
 489
 490         if (args->pad != 0) {
 491                 DRM_INFO("Pad set: 0x%08x\n", args->pad);
 492                 return -EINVAL;
 493         }
 494
 495         bo = vc4_bo_create(dev, args->size, true);
 496         if (IS_ERR(bo))
 497                 return PTR_ERR(bo);
 498
 499         if (copy_from_user(bo->base.vaddr,
 500                              (void __user *)(uintptr_t)args->data,
 501                              args->size)) {
 502                 ret = -EFAULT;
 503                 goto fail;
 504         }
 505         /* Clear the rest of the memory from allocating from the BO
 506          * cache.
 507          */
 508         memset(bo->base.vaddr + args->size, 0,
 509                bo->base.base.size - args->size);
 510
 511         bo->validated_shader = vc4_validate_shader(&bo->base);
 512         if (!bo->validated_shader) {
 513                 ret = -EINVAL;
 514                 goto fail;
 515         }
 516
 517         /* We have to create the handle after validation, to avoid
 518          * races for users to do doing things like mmap the shader BO.
 519          */
 520         ret = drm_gem_handle_create(file_priv, &bo->base.base, &args->handle);
 521
 522  fail:
 523         drm_gem_object_unreference_unlocked(&bo->base.base);
 524
 525         return ret;
 526 }
 527
 528 void vc4_bo_cache_init(struct drm_device *dev)
 529 {
 530         struct vc4_dev *vc4 = to_vc4_dev(dev);
 531
 532         mutex_init(&vc4->bo_lock);
 533
 534         INIT_LIST_HEAD(&vc4->bo_cache.time_list);
 535
 536         INIT_WORK(&vc4->bo_cache.time_work, vc4_bo_cache_time_work);
 537         setup_timer(&vc4->bo_cache.time_timer,
 538                     vc4_bo_cache_time_timer,
 539                     (unsigned long)dev);
 540 }
 541
 542 void vc4_bo_cache_destroy(struct drm_device *dev)
 543 {
 544         struct vc4_dev *vc4 = to_vc4_dev(dev);
 545
 546         del_timer(&vc4->bo_cache.time_timer);
 547         cancel_work_sync(&vc4->bo_cache.time_work);
 548
 549         vc4_bo_cache_purge(dev);
 550
 551         if (vc4->bo_stats.num_allocated) {
 552                 DRM_ERROR("Destroying BO cache while BOs still allocated:\n");
 553                 vc4_bo_stats_dump(vc4);
 554         }
 555 }