drivers/gpu/drm/ttm/ttm_tt.c

   1 /* SPDX-License-Identifier: GPL-2.0 OR MIT */
   2 /**************************************************************************
   3  *
   4  * Copyright (c) 2006-2009 VMware, Inc., Palo Alto, CA., USA
   5  * All Rights Reserved.
   6  *
   7  * Permission is hereby granted, free of charge, to any person obtaining a
   8  * copy of this software and associated documentation files (the
   9  * "Software"), to deal in the Software without restriction, including
  10  * without limitation the rights to use, copy, modify, merge, publish,
  11  * distribute, sub license, and/or sell copies of the Software, and to
  12  * permit persons to whom the Software is furnished to do so, subject to
  13  * the following conditions:
  14  *
  15  * The above copyright notice and this permission notice (including the
  16  * next paragraph) shall be included in all copies or substantial portions
  17  * of the Software.
  18  *
  19  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  20  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  21  * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
  22  * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
  23  * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
  24  * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
  25  * USE OR OTHER DEALINGS IN THE SOFTWARE.
  26  *
  27  **************************************************************************/
  28 /*
  29  * Authors: Thomas Hellstrom <thellstrom-at-vmware-dot-com>
  30  */
  31
  32 #define pr_fmt(fmt) "[TTM] " fmt
  33
  34 #include <linux/sched.h>
  35 #include <linux/pagemap.h>
  36 #include <linux/shmem_fs.h>
  37 #include <linux/file.h>
  38 #include <drm/drm_cache.h>
  39 #include <drm/ttm/ttm_bo_driver.h>
  40
  41 #include "ttm_module.h"
  42
  43 static struct shrinker mm_shrinker;
  44 static atomic_long_t swapable_pages;
  45
  46 /*
  47  * Allocates a ttm structure for the given BO.
  48  */
  49 int ttm_tt_create(struct ttm_buffer_object *bo, bool zero_alloc)
  50 {
  51         struct ttm_device *bdev = bo->bdev;
  52         uint32_t page_flags = 0;
  53
  54         dma_resv_assert_held(bo->base.resv);
  55
  56         if (bo->ttm)
  57                 return 0;
  58
  59         switch (bo->type) {
  60         case ttm_bo_type_device:
  61                 if (zero_alloc)
  62                         page_flags |= TTM_PAGE_FLAG_ZERO_ALLOC;
  63                 break;
  64         case ttm_bo_type_kernel:
  65                 break;
  66         case ttm_bo_type_sg:
  67                 page_flags |= TTM_PAGE_FLAG_SG;
  68                 break;
  69         default:
  70                 pr_err("Illegal buffer object type\n");
  71                 return -EINVAL;
  72         }
  73
  74         bo->ttm = bdev->funcs->ttm_tt_create(bo, page_flags);
  75         if (unlikely(bo->ttm == NULL))
  76                 return -ENOMEM;
  77
  78         return 0;
  79 }
  80
  81 /*
  82  * Allocates storage for pointers to the pages that back the ttm.
  83  */
  84 static int ttm_tt_alloc_page_directory(struct ttm_tt *ttm)
  85 {
  86         ttm->pages = kvmalloc_array(ttm->num_pages, sizeof(void*),
  87                         GFP_KERNEL | __GFP_ZERO);
  88         if (!ttm->pages)
  89                 return -ENOMEM;
  90         return 0;
  91 }
  92
  93 static int ttm_dma_tt_alloc_page_directory(struct ttm_tt *ttm)
  94 {
  95         ttm->pages = kvmalloc_array(ttm->num_pages,
  96                                     sizeof(*ttm->pages) +
  97                                     sizeof(*ttm->dma_address),
  98                                     GFP_KERNEL | __GFP_ZERO);
  99         if (!ttm->pages)
 100                 return -ENOMEM;
 101
 102         ttm->dma_address = (void *)(ttm->pages + ttm->num_pages);
 103         return 0;
 104 }
 105
 106 static int ttm_sg_tt_alloc_page_directory(struct ttm_tt *ttm)
 107 {
 108         ttm->dma_address = kvmalloc_array(ttm->num_pages,
 109                                           sizeof(*ttm->dma_address),
 110                                           GFP_KERNEL | __GFP_ZERO);
 111         if (!ttm->dma_address)
 112                 return -ENOMEM;
 113         return 0;
 114 }
 115
 116 void ttm_tt_destroy_common(struct ttm_device *bdev, struct ttm_tt *ttm)
 117 {
 118         ttm_tt_unpopulate(bdev, ttm);
 119
 120         if (ttm->swap_storage)
 121                 fput(ttm->swap_storage);
 122
 123         ttm->swap_storage = NULL;
 124 }
 125 EXPORT_SYMBOL(ttm_tt_destroy_common);
 126
 127 void ttm_tt_destroy(struct ttm_device *bdev, struct ttm_tt *ttm)
 128 {
 129         bdev->funcs->ttm_tt_destroy(bdev, ttm);
 130 }
 131
 132 static void ttm_tt_init_fields(struct ttm_tt *ttm,
 133                                struct ttm_buffer_object *bo,
 134                                uint32_t page_flags,
 135                                enum ttm_caching caching)
 136 {
 137         ttm->num_pages = PAGE_ALIGN(bo->base.size) >> PAGE_SHIFT;
 138         ttm->caching = ttm_cached;
 139         ttm->page_flags = page_flags;
 140         ttm->dma_address = NULL;
 141         ttm->swap_storage = NULL;
 142         ttm->sg = bo->sg;
 143         ttm->caching = caching;
 144 }
 145
 146 int ttm_tt_init(struct ttm_tt *ttm, struct ttm_buffer_object *bo,
 147                 uint32_t page_flags, enum ttm_caching caching)
 148 {
 149         ttm_tt_init_fields(ttm, bo, page_flags, caching);
 150
 151         if (ttm_tt_alloc_page_directory(ttm)) {
 152                 pr_err("Failed allocating page table\n");
 153                 return -ENOMEM;
 154         }
 155         return 0;
 156 }
 157 EXPORT_SYMBOL(ttm_tt_init);
 158
 159 void ttm_tt_fini(struct ttm_tt *ttm)
 160 {
 161         if (ttm->pages)
 162                 kvfree(ttm->pages);
 163         else
 164                 kvfree(ttm->dma_address);
 165         ttm->pages = NULL;
 166         ttm->dma_address = NULL;
 167 }
 168 EXPORT_SYMBOL(ttm_tt_fini);
 169
 170 int ttm_sg_tt_init(struct ttm_tt *ttm, struct ttm_buffer_object *bo,
 171                    uint32_t page_flags, enum ttm_caching caching)
 172 {
 173         int ret;
 174
 175         ttm_tt_init_fields(ttm, bo, page_flags, caching);
 176
 177         if (page_flags & TTM_PAGE_FLAG_SG)
 178                 ret = ttm_sg_tt_alloc_page_directory(ttm);
 179         else
 180                 ret = ttm_dma_tt_alloc_page_directory(ttm);
 181         if (ret) {
 182                 pr_err("Failed allocating page table\n");
 183                 return -ENOMEM;
 184         }
 185         return 0;
 186 }
 187 EXPORT_SYMBOL(ttm_sg_tt_init);
 188
 189 int ttm_tt_swapin(struct ttm_tt *ttm)
 190 {
 191         struct address_space *swap_space;
 192         struct file *swap_storage;
 193         struct page *from_page;
 194         struct page *to_page;
 195         gfp_t gfp_mask;
 196         int i, ret;
 197
 198         swap_storage = ttm->swap_storage;
 199         BUG_ON(swap_storage == NULL);
 200
 201         swap_space = swap_storage->f_mapping;
 202         gfp_mask = mapping_gfp_mask(swap_space);
 203
 204         for (i = 0; i < ttm->num_pages; ++i) {
 205                 from_page = shmem_read_mapping_page_gfp(swap_space, i,
 206                                                         gfp_mask);
 207                 if (IS_ERR(from_page)) {
 208                         ret = PTR_ERR(from_page);
 209                         goto out_err;
 210                 }
 211                 to_page = ttm->pages[i];
 212                 if (unlikely(to_page == NULL)) {
 213                         ret = -ENOMEM;
 214                         goto out_err;
 215                 }
 216
 217                 copy_highpage(to_page, from_page);
 218                 put_page(from_page);
 219         }
 220
 221         fput(swap_storage);
 222         ttm->swap_storage = NULL;
 223         ttm->page_flags &= ~TTM_PAGE_FLAG_SWAPPED;
 224
 225         return 0;
 226
 227 out_err:
 228         return ret;
 229 }
 230
 231 /**
 232  * ttm_tt_swapout - swap out tt object
 233  *
 234  * @bdev: TTM device structure.
 235  * @ttm: The struct ttm_tt.
 236  * @gfp_flags: Flags to use for memory allocation.
 237  *
 238  * Swapout a TT object to a shmem_file, return number of pages swapped out or
 239  * negative error code.
 240  */
 241 int ttm_tt_swapout(struct ttm_device *bdev, struct ttm_tt *ttm,
 242                    gfp_t gfp_flags)
 243 {
 244         loff_t size = (loff_t)ttm->num_pages << PAGE_SHIFT;
 245         struct address_space *swap_space;
 246         struct file *swap_storage;
 247         struct page *from_page;
 248         struct page *to_page;
 249         int i, ret;
 250
 251         swap_storage = shmem_file_setup("ttm swap", size, 0);
 252         if (IS_ERR(swap_storage)) {
 253                 pr_err("Failed allocating swap storage\n");
 254                 return PTR_ERR(swap_storage);
 255         }
 256
 257         swap_space = swap_storage->f_mapping;
 258         gfp_flags &= mapping_gfp_mask(swap_space);
 259
 260         for (i = 0; i < ttm->num_pages; ++i) {
 261                 from_page = ttm->pages[i];
 262                 if (unlikely(from_page == NULL))
 263                         continue;
 264
 265                 to_page = shmem_read_mapping_page_gfp(swap_space, i, gfp_flags);
 266                 if (IS_ERR(to_page)) {
 267                         ret = PTR_ERR(to_page);
 268                         goto out_err;
 269                 }
 270                 copy_highpage(to_page, from_page);
 271                 set_page_dirty(to_page);
 272                 mark_page_accessed(to_page);
 273                 put_page(to_page);
 274         }
 275
 276         ttm_tt_unpopulate(bdev, ttm);
 277         ttm->swap_storage = swap_storage;
 278         ttm->page_flags |= TTM_PAGE_FLAG_SWAPPED;
 279
 280         return ttm->num_pages;
 281
 282 out_err:
 283         fput(swap_storage);
 284
 285         return ret;
 286 }
 287
 288 static void ttm_tt_add_mapping(struct ttm_device *bdev, struct ttm_tt *ttm)
 289 {
 290         pgoff_t i;
 291
 292         if (ttm->page_flags & TTM_PAGE_FLAG_SG)
 293                 return;
 294
 295         for (i = 0; i < ttm->num_pages; ++i)
 296                 ttm->pages[i]->mapping = bdev->dev_mapping;
 297
 298         atomic_long_add(ttm->num_pages, &swapable_pages);
 299 }
 300
 301 int ttm_tt_populate(struct ttm_device *bdev,
 302                     struct ttm_tt *ttm, struct ttm_operation_ctx *ctx)
 303 {
 304         int ret;
 305
 306         if (!ttm)
 307                 return -EINVAL;
 308
 309         if (ttm_tt_is_populated(ttm))
 310                 return 0;
 311
 312         if (bdev->funcs->ttm_tt_populate)
 313                 ret = bdev->funcs->ttm_tt_populate(bdev, ttm, ctx);
 314         else
 315                 ret = ttm_pool_alloc(&bdev->pool, ttm, ctx);
 316         if (ret)
 317                 return ret;
 318
 319         ttm_tt_add_mapping(bdev, ttm);
 320         ttm->page_flags |= TTM_PAGE_FLAG_PRIV_POPULATED;
 321         if (unlikely(ttm->page_flags & TTM_PAGE_FLAG_SWAPPED)) {
 322                 ret = ttm_tt_swapin(ttm);
 323                 if (unlikely(ret != 0)) {
 324                         ttm_tt_unpopulate(bdev, ttm);
 325                         return ret;
 326                 }
 327         }
 328
 329         return 0;
 330 }
 331 EXPORT_SYMBOL(ttm_tt_populate);
 332
 333 static void ttm_tt_clear_mapping(struct ttm_tt *ttm)
 334 {
 335         pgoff_t i;
 336         struct page **page = ttm->pages;
 337
 338         if (ttm->page_flags & TTM_PAGE_FLAG_SG)
 339                 return;
 340
 341         for (i = 0; i < ttm->num_pages; ++i) {
 342                 (*page)->mapping = NULL;
 343                 (*page++)->index = 0;
 344         }
 345
 346         atomic_long_sub(ttm->num_pages, &swapable_pages);
 347 }
 348
 349 void ttm_tt_unpopulate(struct ttm_device *bdev,
 350                        struct ttm_tt *ttm)
 351 {
 352         if (!ttm_tt_is_populated(ttm))
 353                 return;
 354
 355         ttm_tt_clear_mapping(ttm);
 356         if (bdev->funcs->ttm_tt_unpopulate)
 357                 bdev->funcs->ttm_tt_unpopulate(bdev, ttm);
 358         else
 359                 ttm_pool_free(&bdev->pool, ttm);
 360         ttm->page_flags &= ~TTM_PAGE_FLAG_PRIV_POPULATED;
 361 }
 362
 363 /* As long as pages are available make sure to release at least one */
 364 static unsigned long ttm_tt_shrinker_scan(struct shrinker *shrink,
 365                                           struct shrink_control *sc)
 366 {
 367         struct ttm_operation_ctx ctx = {
 368                 .no_wait_gpu = false
 369         };
 370         int ret;
 371
 372         ret = ttm_global_swapout(&ctx, GFP_NOFS);
 373         return ret < 0 ? SHRINK_EMPTY : ret;
 374 }
 375
 376 /* Return the number of pages available or SHRINK_EMPTY if we have none */
 377 static unsigned long ttm_tt_shrinker_count(struct shrinker *shrink,
 378                                            struct shrink_control *sc)
 379 {
 380         unsigned long num_pages;
 381
 382         num_pages = atomic_long_read(&swapable_pages);
 383         return num_pages ? num_pages : SHRINK_EMPTY;
 384 }
 385
 386 #ifdef CONFIG_DEBUG_FS
 387
 388 /* Test the shrinker functions and dump the result */
 389 static int ttm_tt_debugfs_shrink_show(struct seq_file *m, void *data)
 390 {
 391         struct shrink_control sc = { .gfp_mask = GFP_KERNEL };
 392
 393         fs_reclaim_acquire(GFP_KERNEL);
 394         seq_printf(m, "%lu/%lu\n", ttm_tt_shrinker_count(&mm_shrinker, &sc),
 395                    ttm_tt_shrinker_scan(&mm_shrinker, &sc));
 396         fs_reclaim_release(GFP_KERNEL);
 397
 398         return 0;
 399 }
 400 DEFINE_SHOW_ATTRIBUTE(ttm_tt_debugfs_shrink);
 401
 402 #endif
 403
 404
 405
 406 /**
 407  * ttm_tt_mgr_init - register with the MM shrinker
 408  *
 409  * Register with the MM shrinker for swapping out BOs.
 410  */
 411 int ttm_tt_mgr_init(void)
 412 {
 413 #ifdef CONFIG_DEBUG_FS
 414         debugfs_create_file("tt_shrink", 0400, ttm_debugfs_root, NULL,
 415                             &ttm_tt_debugfs_shrink_fops);
 416 #endif
 417
 418         mm_shrinker.count_objects = ttm_tt_shrinker_count;
 419         mm_shrinker.scan_objects = ttm_tt_shrinker_scan;
 420         mm_shrinker.seeks = 1;
 421         return register_shrinker(&mm_shrinker);
 422 }
 423
 424 /**
 425  * ttm_tt_mgr_fini - unregister our MM shrinker
 426  *
 427  * Unregisters the MM shrinker.
 428  */
 429 void ttm_tt_mgr_fini(void)
 430 {
 431         unregister_shrinker(&mm_shrinker);
 432 }