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