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