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/cc_platform.h>
  35 #include <linux/debugfs.h>
  36 #include <linux/file.h>
  37 #include <linux/module.h>
  38 #include <linux/sched.h>
  39 #include <linux/shmem_fs.h>
  40 #include <drm/drm_cache.h>
  41 #include <drm/drm_device.h>
  42 #include <drm/drm_util.h>
  43 #include <drm/ttm/ttm_bo.h>
  44 #include <drm/ttm/ttm_tt.h>
  45
  46 #include "ttm_module.h"
  47
  48 static unsigned long ttm_pages_limit;
  49
  50 MODULE_PARM_DESC(pages_limit, "Limit for the allocated pages");
  51 module_param_named(pages_limit, ttm_pages_limit, ulong, 0644);
  52
  53 static unsigned long ttm_dma32_pages_limit;
  54
  55 MODULE_PARM_DESC(dma32_pages_limit, "Limit for the allocated DMA32 pages");
  56 module_param_named(dma32_pages_limit, ttm_dma32_pages_limit, ulong, 0644);
  57
  58 static atomic_long_t ttm_pages_allocated;
  59 static atomic_long_t ttm_dma32_pages_allocated;
  60
  61 /*
  62  * Allocates a ttm structure for the given BO.
  63  */
  64 int ttm_tt_create(struct ttm_buffer_object *bo, bool zero_alloc)
  65 {
  66         struct ttm_device *bdev = bo->bdev;
  67         struct drm_device *ddev = bo->base.dev;
  68         uint32_t page_flags = 0;
  69
  70         dma_resv_assert_held(bo->base.resv);
  71
  72         if (bo->ttm)
  73                 return 0;
  74
  75         switch (bo->type) {
  76         case ttm_bo_type_device:
  77                 if (zero_alloc)
  78                         page_flags |= TTM_TT_FLAG_ZERO_ALLOC;
  79                 break;
  80         case ttm_bo_type_kernel:
  81                 break;
  82         case ttm_bo_type_sg:
  83                 page_flags |= TTM_TT_FLAG_EXTERNAL;
  84                 break;
  85         default:
  86                 pr_err("Illegal buffer object type\n");
  87                 return -EINVAL;
  88         }
  89         /*
  90          * When using dma_alloc_coherent with memory encryption the
  91          * mapped TT pages need to be decrypted or otherwise the drivers
  92          * will end up sending encrypted mem to the gpu.
  93          */
  94         if (bdev->pool.use_dma_alloc && cc_platform_has(CC_ATTR_GUEST_MEM_ENCRYPT)) {
  95                 page_flags |= TTM_TT_FLAG_DECRYPTED;
  96                 drm_info_once(ddev, "TT memory decryption enabled.");
  97         }
  98
  99         bo->ttm = bdev->funcs->ttm_tt_create(bo, page_flags);
 100         if (unlikely(bo->ttm == NULL))
 101                 return -ENOMEM;
 102
 103         WARN_ON(bo->ttm->page_flags & TTM_TT_FLAG_EXTERNAL_MAPPABLE &&
 104                 !(bo->ttm->page_flags & TTM_TT_FLAG_EXTERNAL));
 105
 106         return 0;
 107 }
 108 EXPORT_SYMBOL_FOR_TESTS_ONLY(ttm_tt_create);
 109
 110 /*
 111  * Allocates storage for pointers to the pages that back the ttm.
 112  */
 113 static int ttm_tt_alloc_page_directory(struct ttm_tt *ttm)
 114 {
 115         ttm->pages = kvcalloc(ttm->num_pages, sizeof(void*), GFP_KERNEL);
 116         if (!ttm->pages)
 117                 return -ENOMEM;
 118
 119         return 0;
 120 }
 121
 122 static int ttm_dma_tt_alloc_page_directory(struct ttm_tt *ttm)
 123 {
 124         ttm->pages = kvcalloc(ttm->num_pages, sizeof(*ttm->pages) +
 125                               sizeof(*ttm->dma_address), GFP_KERNEL);
 126         if (!ttm->pages)
 127                 return -ENOMEM;
 128
 129         ttm->dma_address = (void *)(ttm->pages + ttm->num_pages);
 130         return 0;
 131 }
 132
 133 static int ttm_sg_tt_alloc_page_directory(struct ttm_tt *ttm)
 134 {
 135         ttm->dma_address = kvcalloc(ttm->num_pages, sizeof(*ttm->dma_address),
 136                                     GFP_KERNEL);
 137         if (!ttm->dma_address)
 138                 return -ENOMEM;
 139
 140         return 0;
 141 }
 142
 143 void ttm_tt_destroy(struct ttm_device *bdev, struct ttm_tt *ttm)
 144 {
 145         bdev->funcs->ttm_tt_destroy(bdev, ttm);
 146 }
 147 EXPORT_SYMBOL_FOR_TESTS_ONLY(ttm_tt_destroy);
 148
 149 static void ttm_tt_init_fields(struct ttm_tt *ttm,
 150                                struct ttm_buffer_object *bo,
 151                                uint32_t page_flags,
 152                                enum ttm_caching caching,
 153                                unsigned long extra_pages)
 154 {
 155         ttm->num_pages = (PAGE_ALIGN(bo->base.size) >> PAGE_SHIFT) + extra_pages;
 156         ttm->page_flags = page_flags;
 157         ttm->dma_address = NULL;
 158         ttm->swap_storage = NULL;
 159         ttm->sg = bo->sg;
 160         ttm->caching = caching;
 161 }
 162
 163 int ttm_tt_init(struct ttm_tt *ttm, struct ttm_buffer_object *bo,
 164                 uint32_t page_flags, enum ttm_caching caching,
 165                 unsigned long extra_pages)
 166 {
 167         ttm_tt_init_fields(ttm, bo, page_flags, caching, extra_pages);
 168
 169         if (ttm_tt_alloc_page_directory(ttm)) {
 170                 pr_err("Failed allocating page table\n");
 171                 return -ENOMEM;
 172         }
 173         return 0;
 174 }
 175 EXPORT_SYMBOL(ttm_tt_init);
 176
 177 void ttm_tt_fini(struct ttm_tt *ttm)
 178 {
 179         WARN_ON(ttm->page_flags & TTM_TT_FLAG_PRIV_POPULATED);
 180
 181         if (ttm->swap_storage)
 182                 fput(ttm->swap_storage);
 183         ttm->swap_storage = NULL;
 184
 185         if (ttm->pages)
 186                 kvfree(ttm->pages);
 187         else
 188                 kvfree(ttm->dma_address);
 189         ttm->pages = NULL;
 190         ttm->dma_address = NULL;
 191 }
 192 EXPORT_SYMBOL(ttm_tt_fini);
 193
 194 int ttm_sg_tt_init(struct ttm_tt *ttm, struct ttm_buffer_object *bo,
 195                    uint32_t page_flags, enum ttm_caching caching)
 196 {
 197         int ret;
 198
 199         ttm_tt_init_fields(ttm, bo, page_flags, caching, 0);
 200
 201         if (page_flags & TTM_TT_FLAG_EXTERNAL)
 202                 ret = ttm_sg_tt_alloc_page_directory(ttm);
 203         else
 204                 ret = ttm_dma_tt_alloc_page_directory(ttm);
 205         if (ret) {
 206                 pr_err("Failed allocating page table\n");
 207                 return -ENOMEM;
 208         }
 209         return 0;
 210 }
 211 EXPORT_SYMBOL(ttm_sg_tt_init);
 212
 213 int ttm_tt_swapin(struct ttm_tt *ttm)
 214 {
 215         struct address_space *swap_space;
 216         struct file *swap_storage;
 217         struct page *from_page;
 218         struct page *to_page;
 219         gfp_t gfp_mask;
 220         int i, ret;
 221
 222         swap_storage = ttm->swap_storage;
 223         BUG_ON(swap_storage == NULL);
 224
 225         swap_space = swap_storage->f_mapping;
 226         gfp_mask = mapping_gfp_mask(swap_space);
 227
 228         for (i = 0; i < ttm->num_pages; ++i) {
 229                 from_page = shmem_read_mapping_page_gfp(swap_space, i,
 230                                                         gfp_mask);
 231                 if (IS_ERR(from_page)) {
 232                         ret = PTR_ERR(from_page);
 233                         goto out_err;
 234                 }
 235                 to_page = ttm->pages[i];
 236                 if (unlikely(to_page == NULL)) {
 237                         ret = -ENOMEM;
 238                         goto out_err;
 239                 }
 240
 241                 copy_highpage(to_page, from_page);
 242                 put_page(from_page);
 243         }
 244
 245         fput(swap_storage);
 246         ttm->swap_storage = NULL;
 247         ttm->page_flags &= ~TTM_TT_FLAG_SWAPPED;
 248
 249         return 0;
 250
 251 out_err:
 252         return ret;
 253 }
 254 EXPORT_SYMBOL_FOR_TESTS_ONLY(ttm_tt_swapin);
 255
 256 /**
 257  * ttm_tt_swapout - swap out tt object
 258  *
 259  * @bdev: TTM device structure.
 260  * @ttm: The struct ttm_tt.
 261  * @gfp_flags: Flags to use for memory allocation.
 262  *
 263  * Swapout a TT object to a shmem_file, return number of pages swapped out or
 264  * negative error code.
 265  */
 266 int ttm_tt_swapout(struct ttm_device *bdev, struct ttm_tt *ttm,
 267                    gfp_t gfp_flags)
 268 {
 269         loff_t size = (loff_t)ttm->num_pages << PAGE_SHIFT;
 270         struct address_space *swap_space;
 271         struct file *swap_storage;
 272         struct page *from_page;
 273         struct page *to_page;
 274         int i, ret;
 275
 276         swap_storage = shmem_file_setup("ttm swap", size, 0);
 277         if (IS_ERR(swap_storage)) {
 278                 pr_err("Failed allocating swap storage\n");
 279                 return PTR_ERR(swap_storage);
 280         }
 281
 282         swap_space = swap_storage->f_mapping;
 283         gfp_flags &= mapping_gfp_mask(swap_space);
 284
 285         for (i = 0; i < ttm->num_pages; ++i) {
 286                 from_page = ttm->pages[i];
 287                 if (unlikely(from_page == NULL))
 288                         continue;
 289
 290                 to_page = shmem_read_mapping_page_gfp(swap_space, i, gfp_flags);
 291                 if (IS_ERR(to_page)) {
 292                         ret = PTR_ERR(to_page);
 293                         goto out_err;
 294                 }
 295                 copy_highpage(to_page, from_page);
 296                 set_page_dirty(to_page);
 297                 mark_page_accessed(to_page);
 298                 put_page(to_page);
 299         }
 300
 301         ttm_tt_unpopulate(bdev, ttm);
 302         ttm->swap_storage = swap_storage;
 303         ttm->page_flags |= TTM_TT_FLAG_SWAPPED;
 304
 305         return ttm->num_pages;
 306
 307 out_err:
 308         fput(swap_storage);
 309
 310         return ret;
 311 }
 312 EXPORT_SYMBOL_FOR_TESTS_ONLY(ttm_tt_swapout);
 313
 314 int ttm_tt_populate(struct ttm_device *bdev,
 315                     struct ttm_tt *ttm, struct ttm_operation_ctx *ctx)
 316 {
 317         int ret;
 318
 319         if (!ttm)
 320                 return -EINVAL;
 321
 322         if (ttm_tt_is_populated(ttm))
 323                 return 0;
 324
 325         if (!(ttm->page_flags & TTM_TT_FLAG_EXTERNAL)) {
 326                 atomic_long_add(ttm->num_pages, &ttm_pages_allocated);
 327                 if (bdev->pool.use_dma32)
 328                         atomic_long_add(ttm->num_pages,
 329                                         &ttm_dma32_pages_allocated);
 330         }
 331
 332         while (atomic_long_read(&ttm_pages_allocated) > ttm_pages_limit ||
 333                atomic_long_read(&ttm_dma32_pages_allocated) >
 334                ttm_dma32_pages_limit) {
 335
 336                 ret = ttm_global_swapout(ctx, GFP_KERNEL);
 337                 if (ret == 0)
 338                         break;
 339                 if (ret < 0)
 340                         goto error;
 341         }
 342
 343         if (bdev->funcs->ttm_tt_populate)
 344                 ret = bdev->funcs->ttm_tt_populate(bdev, ttm, ctx);
 345         else
 346                 ret = ttm_pool_alloc(&bdev->pool, ttm, ctx);
 347         if (ret)
 348                 goto error;
 349
 350         ttm->page_flags |= TTM_TT_FLAG_PRIV_POPULATED;
 351         if (unlikely(ttm->page_flags & TTM_TT_FLAG_SWAPPED)) {
 352                 ret = ttm_tt_swapin(ttm);
 353                 if (unlikely(ret != 0)) {
 354                         ttm_tt_unpopulate(bdev, ttm);
 355                         return ret;
 356                 }
 357         }
 358
 359         return 0;
 360
 361 error:
 362         if (!(ttm->page_flags & TTM_TT_FLAG_EXTERNAL)) {
 363                 atomic_long_sub(ttm->num_pages, &ttm_pages_allocated);
 364                 if (bdev->pool.use_dma32)
 365                         atomic_long_sub(ttm->num_pages,
 366                                         &ttm_dma32_pages_allocated);
 367         }
 368         return ret;
 369 }
 370
 371 #if IS_ENABLED(CONFIG_DRM_TTM_KUNIT_TEST)
 372 EXPORT_SYMBOL(ttm_tt_populate);
 373 #endif
 374
 375 void ttm_tt_unpopulate(struct ttm_device *bdev, struct ttm_tt *ttm)
 376 {
 377         if (!ttm_tt_is_populated(ttm))
 378                 return;
 379
 380         if (bdev->funcs->ttm_tt_unpopulate)
 381                 bdev->funcs->ttm_tt_unpopulate(bdev, ttm);
 382         else
 383                 ttm_pool_free(&bdev->pool, ttm);
 384
 385         if (!(ttm->page_flags & TTM_TT_FLAG_EXTERNAL)) {
 386                 atomic_long_sub(ttm->num_pages, &ttm_pages_allocated);
 387                 if (bdev->pool.use_dma32)
 388                         atomic_long_sub(ttm->num_pages,
 389                                         &ttm_dma32_pages_allocated);
 390         }
 391
 392         ttm->page_flags &= ~TTM_TT_FLAG_PRIV_POPULATED;
 393 }
 394 EXPORT_SYMBOL_FOR_TESTS_ONLY(ttm_tt_unpopulate);
 395
 396 #ifdef CONFIG_DEBUG_FS
 397
 398 /* Test the shrinker functions and dump the result */
 399 static int ttm_tt_debugfs_shrink_show(struct seq_file *m, void *data)
 400 {
 401         struct ttm_operation_ctx ctx = { false, false };
 402
 403         seq_printf(m, "%d\n", ttm_global_swapout(&ctx, GFP_KERNEL));
 404         return 0;
 405 }
 406 DEFINE_SHOW_ATTRIBUTE(ttm_tt_debugfs_shrink);
 407
 408 #endif
 409
 410
 411 /*
 412  * ttm_tt_mgr_init - register with the MM shrinker
 413  *
 414  * Register with the MM shrinker for swapping out BOs.
 415  */
 416 void ttm_tt_mgr_init(unsigned long num_pages, unsigned long num_dma32_pages)
 417 {
 418 #ifdef CONFIG_DEBUG_FS
 419         debugfs_create_file("tt_shrink", 0400, ttm_debugfs_root, NULL,
 420                             &ttm_tt_debugfs_shrink_fops);
 421 #endif
 422
 423         if (!ttm_pages_limit)
 424                 ttm_pages_limit = num_pages;
 425
 426         if (!ttm_dma32_pages_limit)
 427                 ttm_dma32_pages_limit = num_dma32_pages;
 428 }
 429
 430 static void ttm_kmap_iter_tt_map_local(struct ttm_kmap_iter *iter,
 431                                        struct iosys_map *dmap,
 432                                        pgoff_t i)
 433 {
 434         struct ttm_kmap_iter_tt *iter_tt =
 435                 container_of(iter, typeof(*iter_tt), base);
 436
 437         iosys_map_set_vaddr(dmap, kmap_local_page_prot(iter_tt->tt->pages[i],
 438                                                        iter_tt->prot));
 439 }
 440
 441 static void ttm_kmap_iter_tt_unmap_local(struct ttm_kmap_iter *iter,
 442                                          struct iosys_map *map)
 443 {
 444         kunmap_local(map->vaddr);
 445 }
 446
 447 static const struct ttm_kmap_iter_ops ttm_kmap_iter_tt_ops = {
 448         .map_local = ttm_kmap_iter_tt_map_local,
 449         .unmap_local = ttm_kmap_iter_tt_unmap_local,
 450         .maps_tt = true,
 451 };
 452
 453 /**
 454  * ttm_kmap_iter_tt_init - Initialize a struct ttm_kmap_iter_tt
 455  * @iter_tt: The struct ttm_kmap_iter_tt to initialize.
 456  * @tt: Struct ttm_tt holding page pointers of the struct ttm_resource.
 457  *
 458  * Return: Pointer to the embedded struct ttm_kmap_iter.
 459  */
 460 struct ttm_kmap_iter *
 461 ttm_kmap_iter_tt_init(struct ttm_kmap_iter_tt *iter_tt,
 462                       struct ttm_tt *tt)
 463 {
 464         iter_tt->base.ops = &ttm_kmap_iter_tt_ops;
 465         iter_tt->tt = tt;
 466         if (tt)
 467                 iter_tt->prot = ttm_prot_from_caching(tt->caching, PAGE_KERNEL);
 468         else
 469                 iter_tt->prot = PAGE_KERNEL;
 470
 471         return &iter_tt->base;
 472 }
 473 EXPORT_SYMBOL(ttm_kmap_iter_tt_init);
 474
 475 unsigned long ttm_tt_pages_limit(void)
 476 {
 477         return ttm_pages_limit;
 478 }
 479 EXPORT_SYMBOL(ttm_tt_pages_limit);