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