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
 255 /**
 256  * ttm_tt_swapout - swap out tt object
 257  *
 258  * @bdev: TTM device structure.
 259  * @ttm: The struct ttm_tt.
 260  * @gfp_flags: Flags to use for memory allocation.
 261  *
 262  * Swapout a TT object to a shmem_file, return number of pages swapped out or
 263  * negative error code.
 264  */
 265 int ttm_tt_swapout(struct ttm_device *bdev, struct ttm_tt *ttm,
 266                    gfp_t gfp_flags)
 267 {
 268         loff_t size = (loff_t)ttm->num_pages << PAGE_SHIFT;
 269         struct address_space *swap_space;
 270         struct file *swap_storage;
 271         struct page *from_page;
 272         struct page *to_page;
 273         int i, ret;
 274
 275         swap_storage = shmem_file_setup("ttm swap", size, 0);
 276         if (IS_ERR(swap_storage)) {
 277                 pr_err("Failed allocating swap storage\n");
 278                 return PTR_ERR(swap_storage);
 279         }
 280
 281         swap_space = swap_storage->f_mapping;
 282         gfp_flags &= mapping_gfp_mask(swap_space);
 283
 284         for (i = 0; i < ttm->num_pages; ++i) {
 285                 from_page = ttm->pages[i];
 286                 if (unlikely(from_page == NULL))
 287                         continue;
 288
 289                 to_page = shmem_read_mapping_page_gfp(swap_space, i, gfp_flags);
 290                 if (IS_ERR(to_page)) {
 291                         ret = PTR_ERR(to_page);
 292                         goto out_err;
 293                 }
 294                 copy_highpage(to_page, from_page);
 295                 set_page_dirty(to_page);
 296                 mark_page_accessed(to_page);
 297                 put_page(to_page);
 298         }
 299
 300         ttm_tt_unpopulate(bdev, ttm);
 301         ttm->swap_storage = swap_storage;
 302         ttm->page_flags |= TTM_TT_FLAG_SWAPPED;
 303
 304         return ttm->num_pages;
 305
 306 out_err:
 307         fput(swap_storage);
 308
 309         return ret;
 310 }
 311
 312 int ttm_tt_populate(struct ttm_device *bdev,
 313                     struct ttm_tt *ttm, struct ttm_operation_ctx *ctx)
 314 {
 315         int ret;
 316
 317         if (!ttm)
 318                 return -EINVAL;
 319
 320         if (ttm_tt_is_populated(ttm))
 321                 return 0;
 322
 323         if (!(ttm->page_flags & TTM_TT_FLAG_EXTERNAL)) {
 324                 atomic_long_add(ttm->num_pages, &ttm_pages_allocated);
 325                 if (bdev->pool.use_dma32)
 326                         atomic_long_add(ttm->num_pages,
 327                                         &ttm_dma32_pages_allocated);
 328         }
 329
 330         while (atomic_long_read(&ttm_pages_allocated) > ttm_pages_limit ||
 331                atomic_long_read(&ttm_dma32_pages_allocated) >
 332                ttm_dma32_pages_limit) {
 333
 334                 ret = ttm_global_swapout(ctx, GFP_KERNEL);
 335                 if (ret == 0)
 336                         break;
 337                 if (ret < 0)
 338                         goto error;
 339         }
 340
 341         if (bdev->funcs->ttm_tt_populate)
 342                 ret = bdev->funcs->ttm_tt_populate(bdev, ttm, ctx);
 343         else
 344                 ret = ttm_pool_alloc(&bdev->pool, ttm, ctx);
 345         if (ret)
 346                 goto error;
 347
 348         ttm->page_flags |= TTM_TT_FLAG_PRIV_POPULATED;
 349         if (unlikely(ttm->page_flags & TTM_TT_FLAG_SWAPPED)) {
 350                 ret = ttm_tt_swapin(ttm);
 351                 if (unlikely(ret != 0)) {
 352                         ttm_tt_unpopulate(bdev, ttm);
 353                         return ret;
 354                 }
 355         }
 356
 357         return 0;
 358
 359 error:
 360         if (!(ttm->page_flags & TTM_TT_FLAG_EXTERNAL)) {
 361                 atomic_long_sub(ttm->num_pages, &ttm_pages_allocated);
 362                 if (bdev->pool.use_dma32)
 363                         atomic_long_sub(ttm->num_pages,
 364                                         &ttm_dma32_pages_allocated);
 365         }
 366         return ret;
 367 }
 368 EXPORT_SYMBOL(ttm_tt_populate);
 369
 370 void ttm_tt_unpopulate(struct ttm_device *bdev, struct ttm_tt *ttm)
 371 {
 372         if (!ttm_tt_is_populated(ttm))
 373                 return;
 374
 375         if (bdev->funcs->ttm_tt_unpopulate)
 376                 bdev->funcs->ttm_tt_unpopulate(bdev, ttm);
 377         else
 378                 ttm_pool_free(&bdev->pool, ttm);
 379
 380         if (!(ttm->page_flags & TTM_TT_FLAG_EXTERNAL)) {
 381                 atomic_long_sub(ttm->num_pages, &ttm_pages_allocated);
 382                 if (bdev->pool.use_dma32)
 383                         atomic_long_sub(ttm->num_pages,
 384                                         &ttm_dma32_pages_allocated);
 385         }
 386
 387         ttm->page_flags &= ~TTM_TT_FLAG_PRIV_POPULATED;
 388 }
 389
 390 #ifdef CONFIG_DEBUG_FS
 391
 392 /* Test the shrinker functions and dump the result */
 393 static int ttm_tt_debugfs_shrink_show(struct seq_file *m, void *data)
 394 {
 395         struct ttm_operation_ctx ctx = { false, false };
 396
 397         seq_printf(m, "%d\n", ttm_global_swapout(&ctx, GFP_KERNEL));
 398         return 0;
 399 }
 400 DEFINE_SHOW_ATTRIBUTE(ttm_tt_debugfs_shrink);
 401
 402 #endif
 403
 404
 405 /*
 406  * ttm_tt_mgr_init - register with the MM shrinker
 407  *
 408  * Register with the MM shrinker for swapping out BOs.
 409  */
 410 void ttm_tt_mgr_init(unsigned long num_pages, unsigned long num_dma32_pages)
 411 {
 412 #ifdef CONFIG_DEBUG_FS
 413         debugfs_create_file("tt_shrink", 0400, ttm_debugfs_root, NULL,
 414                             &ttm_tt_debugfs_shrink_fops);
 415 #endif
 416
 417         if (!ttm_pages_limit)
 418                 ttm_pages_limit = num_pages;
 419
 420         if (!ttm_dma32_pages_limit)
 421                 ttm_dma32_pages_limit = num_dma32_pages;
 422 }
 423
 424 static void ttm_kmap_iter_tt_map_local(struct ttm_kmap_iter *iter,
 425                                        struct iosys_map *dmap,
 426                                        pgoff_t i)
 427 {
 428         struct ttm_kmap_iter_tt *iter_tt =
 429                 container_of(iter, typeof(*iter_tt), base);
 430
 431         iosys_map_set_vaddr(dmap, kmap_local_page_prot(iter_tt->tt->pages[i],
 432                                                        iter_tt->prot));
 433 }
 434
 435 static void ttm_kmap_iter_tt_unmap_local(struct ttm_kmap_iter *iter,
 436                                          struct iosys_map *map)
 437 {
 438         kunmap_local(map->vaddr);
 439 }
 440
 441 static const struct ttm_kmap_iter_ops ttm_kmap_iter_tt_ops = {
 442         .map_local = ttm_kmap_iter_tt_map_local,
 443         .unmap_local = ttm_kmap_iter_tt_unmap_local,
 444         .maps_tt = true,
 445 };
 446
 447 /**
 448  * ttm_kmap_iter_tt_init - Initialize a struct ttm_kmap_iter_tt
 449  * @iter_tt: The struct ttm_kmap_iter_tt to initialize.
 450  * @tt: Struct ttm_tt holding page pointers of the struct ttm_resource.
 451  *
 452  * Return: Pointer to the embedded struct ttm_kmap_iter.
 453  */
 454 struct ttm_kmap_iter *
 455 ttm_kmap_iter_tt_init(struct ttm_kmap_iter_tt *iter_tt,
 456                       struct ttm_tt *tt)
 457 {
 458         iter_tt->base.ops = &ttm_kmap_iter_tt_ops;
 459         iter_tt->tt = tt;
 460         if (tt)
 461                 iter_tt->prot = ttm_prot_from_caching(tt->caching, PAGE_KERNEL);
 462         else
 463                 iter_tt->prot = PAGE_KERNEL;
 464
 465         return &iter_tt->base;
 466 }
 467 EXPORT_SYMBOL(ttm_kmap_iter_tt_init);
 468
 469 unsigned long ttm_tt_pages_limit(void)
 470 {
 471         return ttm_pages_limit;
 472 }
 473 EXPORT_SYMBOL(ttm_tt_pages_limit);