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); 453