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/shmem_fs.h>
  36 #include <linux/file.h>
  37 #include <linux/module.h>
  38 #include <drm/drm_cache.h>
  39 #include <drm/ttm/ttm_bo_driver.h>
  40
  41 #include "ttm_module.h"
  42
  43 static unsigned long ttm_pages_limit;
  44
  45 MODULE_PARM_DESC(pages_limit, "Limit for the allocated pages");
  46 module_param_named(pages_limit, ttm_pages_limit, ulong, 0644);
  47
  48 static unsigned long ttm_dma32_pages_limit;
  49
  50 MODULE_PARM_DESC(dma32_pages_limit, "Limit for the allocated DMA32 pages");
  51 module_param_named(dma32_pages_limit, ttm_dma32_pages_limit, ulong, 0644);
  52
  53 static atomic_long_t ttm_pages_allocated;
  54 static atomic_long_t ttm_dma32_pages_allocated;
  55
  56 /*
  57  * Allocates a ttm structure for the given BO.
  58  */
  59 int ttm_tt_create(struct ttm_buffer_object *bo, bool zero_alloc)
  60 {
  61         struct ttm_device *bdev = bo->bdev;
  62         uint32_t page_flags = 0;
  63
  64         dma_resv_assert_held(bo->base.resv);
  65
  66         if (bo->ttm)
  67                 return 0;
  68
  69         switch (bo->type) {
  70         case ttm_bo_type_device:
  71                 if (zero_alloc)
  72                         page_flags |= TTM_TT_FLAG_ZERO_ALLOC;
  73                 break;
  74         case ttm_bo_type_kernel:
  75                 break;
  76         case ttm_bo_type_sg:
  77                 page_flags |= TTM_TT_FLAG_EXTERNAL;
  78                 break;
  79         default:
  80                 pr_err("Illegal buffer object type\n");
  81                 return -EINVAL;
  82         }
  83
  84         bo->ttm = bdev->funcs->ttm_tt_create(bo, page_flags);
  85         if (unlikely(bo->ttm == NULL))
  86                 return -ENOMEM;
  87
  88         WARN_ON(bo->ttm->page_flags & TTM_TT_FLAG_EXTERNAL_MAPPABLE &&
  89                 !(bo->ttm->page_flags & TTM_TT_FLAG_EXTERNAL));
  90
  91         return 0;
  92 }
  93
  94 /*
  95  * Allocates storage for pointers to the pages that back the ttm.
  96  */
  97 static int ttm_tt_alloc_page_directory(struct ttm_tt *ttm)
  98 {
  99         ttm->pages = kvmalloc_array(ttm->num_pages, sizeof(void*),
 100                         GFP_KERNEL | __GFP_ZERO);
 101         if (!ttm->pages)
 102                 return -ENOMEM;
 103         return 0;
 104 }
 105
 106 static int ttm_dma_tt_alloc_page_directory(struct ttm_tt *ttm)
 107 {
 108         ttm->pages = kvmalloc_array(ttm->num_pages,
 109                                     sizeof(*ttm->pages) +
 110                                     sizeof(*ttm->dma_address),
 111                                     GFP_KERNEL | __GFP_ZERO);
 112         if (!ttm->pages)
 113                 return -ENOMEM;
 114
 115         ttm->dma_address = (void *)(ttm->pages + ttm->num_pages);
 116         return 0;
 117 }
 118
 119 static int ttm_sg_tt_alloc_page_directory(struct ttm_tt *ttm)
 120 {
 121         ttm->dma_address = kvmalloc_array(ttm->num_pages,
 122                                           sizeof(*ttm->dma_address),
 123                                           GFP_KERNEL | __GFP_ZERO);
 124         if (!ttm->dma_address)
 125                 return -ENOMEM;
 126         return 0;
 127 }
 128
 129 void ttm_tt_destroy(struct ttm_device *bdev, struct ttm_tt *ttm)
 130 {
 131         bdev->funcs->ttm_tt_destroy(bdev, ttm);
 132 }
 133
 134 static void ttm_tt_init_fields(struct ttm_tt *ttm,
 135                                struct ttm_buffer_object *bo,
 136                                uint32_t page_flags,
 137                                enum ttm_caching caching,
 138                                unsigned long extra_pages)
 139 {
 140         ttm->num_pages = (PAGE_ALIGN(bo->base.size) >> PAGE_SHIFT) + extra_pages;
 141         ttm->caching = ttm_cached;
 142         ttm->page_flags = page_flags;
 143         ttm->dma_address = NULL;
 144         ttm->swap_storage = NULL;
 145         ttm->sg = bo->sg;
 146         ttm->caching = caching;
 147 }
 148
 149 int ttm_tt_init(struct ttm_tt *ttm, struct ttm_buffer_object *bo,
 150                 uint32_t page_flags, enum ttm_caching caching,
 151                 unsigned long extra_pages)
 152 {
 153         ttm_tt_init_fields(ttm, bo, page_flags, caching, extra_pages);
 154
 155         if (ttm_tt_alloc_page_directory(ttm)) {
 156                 pr_err("Failed allocating page table\n");
 157                 return -ENOMEM;
 158         }
 159         return 0;
 160 }
 161 EXPORT_SYMBOL(ttm_tt_init);
 162
 163 void ttm_tt_fini(struct ttm_tt *ttm)
 164 {
 165         WARN_ON(ttm->page_flags & TTM_TT_FLAG_PRIV_POPULATED);
 166
 167         if (ttm->swap_storage)
 168                 fput(ttm->swap_storage);
 169         ttm->swap_storage = NULL;
 170
 171         if (ttm->pages)
 172                 kvfree(ttm->pages);
 173         else
 174                 kvfree(ttm->dma_address);
 175         ttm->pages = NULL;
 176         ttm->dma_address = NULL;
 177 }
 178 EXPORT_SYMBOL(ttm_tt_fini);
 179
 180 int ttm_sg_tt_init(struct ttm_tt *ttm, struct ttm_buffer_object *bo,
 181                    uint32_t page_flags, enum ttm_caching caching)
 182 {
 183         int ret;
 184
 185         ttm_tt_init_fields(ttm, bo, page_flags, caching, 0);
 186
 187         if (page_flags & TTM_TT_FLAG_EXTERNAL)
 188                 ret = ttm_sg_tt_alloc_page_directory(ttm);
 189         else
 190                 ret = ttm_dma_tt_alloc_page_directory(ttm);
 191         if (ret) {
 192                 pr_err("Failed allocating page table\n");
 193                 return -ENOMEM;
 194         }
 195         return 0;
 196 }
 197 EXPORT_SYMBOL(ttm_sg_tt_init);
 198
 199 int ttm_tt_swapin(struct ttm_tt *ttm)
 200 {
 201         struct address_space *swap_space;
 202         struct file *swap_storage;
 203         struct page *from_page;
 204         struct page *to_page;
 205         gfp_t gfp_mask;
 206         int i, ret;
 207
 208         swap_storage = ttm->swap_storage;
 209         BUG_ON(swap_storage == NULL);
 210
 211         swap_space = swap_storage->f_mapping;
 212         gfp_mask = mapping_gfp_mask(swap_space);
 213
 214         for (i = 0; i < ttm->num_pages; ++i) {
 215                 from_page = shmem_read_mapping_page_gfp(swap_space, i,
 216                                                         gfp_mask);
 217                 if (IS_ERR(from_page)) {
 218                         ret = PTR_ERR(from_page);
 219                         goto out_err;
 220                 }
 221                 to_page = ttm->pages[i];
 222                 if (unlikely(to_page == NULL)) {
 223                         ret = -ENOMEM;
 224                         goto out_err;
 225                 }
 226
 227                 copy_highpage(to_page, from_page);
 228                 put_page(from_page);
 229         }
 230
 231         fput(swap_storage);
 232         ttm->swap_storage = NULL;
 233         ttm->page_flags &= ~TTM_TT_FLAG_SWAPPED;
 234
 235         return 0;
 236
 237 out_err:
 238         return ret;
 239 }
 240
 241 /**
 242  * ttm_tt_swapout - swap out tt object
 243  *
 244  * @bdev: TTM device structure.
 245  * @ttm: The struct ttm_tt.
 246  * @gfp_flags: Flags to use for memory allocation.
 247  *
 248  * Swapout a TT object to a shmem_file, return number of pages swapped out or
 249  * negative error code.
 250  */
 251 int ttm_tt_swapout(struct ttm_device *bdev, struct ttm_tt *ttm,
 252                    gfp_t gfp_flags)
 253 {
 254         loff_t size = (loff_t)ttm->num_pages << PAGE_SHIFT;
 255         struct address_space *swap_space;
 256         struct file *swap_storage;
 257         struct page *from_page;
 258         struct page *to_page;
 259         int i, ret;
 260
 261         swap_storage = shmem_file_setup("ttm swap", size, 0);
 262         if (IS_ERR(swap_storage)) {
 263                 pr_err("Failed allocating swap storage\n");
 264                 return PTR_ERR(swap_storage);
 265         }
 266
 267         swap_space = swap_storage->f_mapping;
 268         gfp_flags &= mapping_gfp_mask(swap_space);
 269
 270         for (i = 0; i < ttm->num_pages; ++i) {
 271                 from_page = ttm->pages[i];
 272                 if (unlikely(from_page == NULL))
 273                         continue;
 274
 275                 to_page = shmem_read_mapping_page_gfp(swap_space, i, gfp_flags);
 276                 if (IS_ERR(to_page)) {
 277                         ret = PTR_ERR(to_page);
 278                         goto out_err;
 279                 }
 280                 copy_highpage(to_page, from_page);
 281                 set_page_dirty(to_page);
 282                 mark_page_accessed(to_page);
 283                 put_page(to_page);
 284         }
 285
 286         ttm_tt_unpopulate(bdev, ttm);
 287         ttm->swap_storage = swap_storage;
 288         ttm->page_flags |= TTM_TT_FLAG_SWAPPED;
 289
 290         return ttm->num_pages;
 291
 292 out_err:
 293         fput(swap_storage);
 294
 295         return ret;
 296 }
 297
 298 int ttm_tt_populate(struct ttm_device *bdev,
 299                     struct ttm_tt *ttm, struct ttm_operation_ctx *ctx)
 300 {
 301         int ret;
 302
 303         if (!ttm)
 304                 return -EINVAL;
 305
 306         if (ttm_tt_is_populated(ttm))
 307                 return 0;
 308
 309         if (!(ttm->page_flags & TTM_TT_FLAG_EXTERNAL)) {
 310                 atomic_long_add(ttm->num_pages, &ttm_pages_allocated);
 311                 if (bdev->pool.use_dma32)
 312                         atomic_long_add(ttm->num_pages,
 313                                         &ttm_dma32_pages_allocated);
 314         }
 315
 316         while (atomic_long_read(&ttm_pages_allocated) > ttm_pages_limit ||
 317                atomic_long_read(&ttm_dma32_pages_allocated) >
 318                ttm_dma32_pages_limit) {
 319
 320                 ret = ttm_global_swapout(ctx, GFP_KERNEL);
 321                 if (ret == 0)
 322                         break;
 323                 if (ret < 0)
 324                         goto error;
 325         }
 326
 327         if (bdev->funcs->ttm_tt_populate)
 328                 ret = bdev->funcs->ttm_tt_populate(bdev, ttm, ctx);
 329         else
 330                 ret = ttm_pool_alloc(&bdev->pool, ttm, ctx);
 331         if (ret)
 332                 goto error;
 333
 334         ttm->page_flags |= TTM_TT_FLAG_PRIV_POPULATED;
 335         if (unlikely(ttm->page_flags & TTM_TT_FLAG_SWAPPED)) {
 336                 ret = ttm_tt_swapin(ttm);
 337                 if (unlikely(ret != 0)) {
 338                         ttm_tt_unpopulate(bdev, ttm);
 339                         return ret;
 340                 }
 341         }
 342
 343         return 0;
 344
 345 error:
 346         if (!(ttm->page_flags & TTM_TT_FLAG_EXTERNAL)) {
 347                 atomic_long_sub(ttm->num_pages, &ttm_pages_allocated);
 348                 if (bdev->pool.use_dma32)
 349                         atomic_long_sub(ttm->num_pages,
 350                                         &ttm_dma32_pages_allocated);
 351         }
 352         return ret;
 353 }
 354 EXPORT_SYMBOL(ttm_tt_populate);
 355
 356 void ttm_tt_unpopulate(struct ttm_device *bdev, struct ttm_tt *ttm)
 357 {
 358         if (!ttm_tt_is_populated(ttm))
 359                 return;
 360
 361         if (bdev->funcs->ttm_tt_unpopulate)
 362                 bdev->funcs->ttm_tt_unpopulate(bdev, ttm);
 363         else
 364                 ttm_pool_free(&bdev->pool, ttm);
 365
 366         if (!(ttm->page_flags & TTM_TT_FLAG_EXTERNAL)) {
 367                 atomic_long_sub(ttm->num_pages, &ttm_pages_allocated);
 368                 if (bdev->pool.use_dma32)
 369                         atomic_long_sub(ttm->num_pages,
 370                                         &ttm_dma32_pages_allocated);
 371         }
 372
 373         ttm->page_flags &= ~TTM_TT_FLAG_PRIV_POPULATED;
 374 }
 375
 376 #ifdef CONFIG_DEBUG_FS
 377
 378 /* Test the shrinker functions and dump the result */
 379 static int ttm_tt_debugfs_shrink_show(struct seq_file *m, void *data)
 380 {
 381         struct ttm_operation_ctx ctx = { false, false };
 382
 383         seq_printf(m, "%d\n", ttm_global_swapout(&ctx, GFP_KERNEL));
 384         return 0;
 385 }
 386 DEFINE_SHOW_ATTRIBUTE(ttm_tt_debugfs_shrink);
 387
 388 #endif
 389
 390
 391 /*
 392  * ttm_tt_mgr_init - register with the MM shrinker
 393  *
 394  * Register with the MM shrinker for swapping out BOs.
 395  */
 396 void ttm_tt_mgr_init(unsigned long num_pages, unsigned long num_dma32_pages)
 397 {
 398 #ifdef CONFIG_DEBUG_FS
 399         debugfs_create_file("tt_shrink", 0400, ttm_debugfs_root, NULL,
 400                             &ttm_tt_debugfs_shrink_fops);
 401 #endif
 402
 403         if (!ttm_pages_limit)
 404                 ttm_pages_limit = num_pages;
 405
 406         if (!ttm_dma32_pages_limit)
 407                 ttm_dma32_pages_limit = num_dma32_pages;
 408 }
 409
 410 static void ttm_kmap_iter_tt_map_local(struct ttm_kmap_iter *iter,
 411                                        struct iosys_map *dmap,
 412                                        pgoff_t i)
 413 {
 414         struct ttm_kmap_iter_tt *iter_tt =
 415                 container_of(iter, typeof(*iter_tt), base);
 416
 417         iosys_map_set_vaddr(dmap, kmap_local_page_prot(iter_tt->tt->pages[i],
 418                                                        iter_tt->prot));
 419 }
 420
 421 static void ttm_kmap_iter_tt_unmap_local(struct ttm_kmap_iter *iter,
 422                                          struct iosys_map *map)
 423 {
 424         kunmap_local(map->vaddr);
 425 }
 426
 427 static const struct ttm_kmap_iter_ops ttm_kmap_iter_tt_ops = {
 428         .map_local = ttm_kmap_iter_tt_map_local,
 429         .unmap_local = ttm_kmap_iter_tt_unmap_local,
 430         .maps_tt = true,
 431 };
 432
 433 /**
 434  * ttm_kmap_iter_tt_init - Initialize a struct ttm_kmap_iter_tt
 435  * @iter_tt: The struct ttm_kmap_iter_tt to initialize.
 436  * @tt: Struct ttm_tt holding page pointers of the struct ttm_resource.
 437  *
 438  * Return: Pointer to the embedded struct ttm_kmap_iter.
 439  */
 440 struct ttm_kmap_iter *
 441 ttm_kmap_iter_tt_init(struct ttm_kmap_iter_tt *iter_tt,
 442                       struct ttm_tt *tt)
 443 {
 444         iter_tt->base.ops = &ttm_kmap_iter_tt_ops;
 445         iter_tt->tt = tt;
 446         if (tt)
 447                 iter_tt->prot = ttm_prot_from_caching(tt->caching, PAGE_KERNEL);
 448         else
 449                 iter_tt->prot = PAGE_KERNEL;
 450
 451         return &iter_tt->base;
 452 }
 453 EXPORT_SYMBOL(ttm_kmap_iter_tt_init);