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/pagemap.h> 36 #include <linux/shmem_fs.h> 37 #include <linux/file.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_PAGE_FLAG_ZERO_ALLOC; 73 break; 74 case ttm_bo_type_kernel: 75 break; 76 case ttm_bo_type_sg: 77 page_flags |= TTM_PAGE_FLAG_SG; 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 return 0; 89 } 90 91 /* 92 * Allocates storage for pointers to the pages that back the ttm. 93 */ 94 static int ttm_tt_alloc_page_directory(struct ttm_tt *ttm) 95 { 96 ttm->pages = kvmalloc_array(ttm->num_pages, sizeof(void*), 97 GFP_KERNEL | __GFP_ZERO); 98 if (!ttm->pages) 99 return -ENOMEM; 100 return 0; 101 } 102 103 static int ttm_dma_tt_alloc_page_directory(struct ttm_tt *ttm) 104 { 105 ttm->pages = kvmalloc_array(ttm->num_pages, 106 sizeof(*ttm->pages) + 107 sizeof(*ttm->dma_address), 108 GFP_KERNEL | __GFP_ZERO); 109 if (!ttm->pages) 110 return -ENOMEM; 111 112 ttm->dma_address = (void *)(ttm->pages + ttm->num_pages); 113 return 0; 114 } 115 116 static int ttm_sg_tt_alloc_page_directory(struct ttm_tt *ttm) 117 { 118 ttm->dma_address = kvmalloc_array(ttm->num_pages, 119 sizeof(*ttm->dma_address), 120 GFP_KERNEL | __GFP_ZERO); 121 if (!ttm->dma_address) 122 return -ENOMEM; 123 return 0; 124 } 125 126 void ttm_tt_destroy_common(struct ttm_device *bdev, struct ttm_tt *ttm) 127 { 128 ttm_tt_unpopulate(bdev, ttm); 129 130 if (ttm->swap_storage) 131 fput(ttm->swap_storage); 132 133 ttm->swap_storage = NULL; 134 } 135 EXPORT_SYMBOL(ttm_tt_destroy_common); 136 137 void ttm_tt_destroy(struct ttm_device *bdev, struct ttm_tt *ttm) 138 { 139 bdev->funcs->ttm_tt_destroy(bdev, ttm); 140 } 141 142 static void ttm_tt_init_fields(struct ttm_tt *ttm, 143 struct ttm_buffer_object *bo, 144 uint32_t page_flags, 145 enum ttm_caching caching) 146 { 147 ttm->num_pages = PAGE_ALIGN(bo->base.size) >> PAGE_SHIFT; 148 ttm->caching = ttm_cached; 149 ttm->page_flags = page_flags; 150 ttm->dma_address = NULL; 151 ttm->swap_storage = NULL; 152 ttm->sg = bo->sg; 153 ttm->caching = caching; 154 } 155 156 int ttm_tt_init(struct ttm_tt *ttm, struct ttm_buffer_object *bo, 157 uint32_t page_flags, enum ttm_caching caching) 158 { 159 ttm_tt_init_fields(ttm, bo, page_flags, caching); 160 161 if (ttm_tt_alloc_page_directory(ttm)) { 162 pr_err("Failed allocating page table\n"); 163 return -ENOMEM; 164 } 165 return 0; 166 } 167 EXPORT_SYMBOL(ttm_tt_init); 168 169 void ttm_tt_fini(struct ttm_tt *ttm) 170 { 171 if (ttm->pages) 172 kvfree(ttm->pages); 173 else 174 kvfree(ttm->dma_address); 175 ttm->pages = NULL; 176 ttm->dma_address = NULL; 177 } 178 EXPORT_SYMBOL(ttm_tt_fini); 179 180 int ttm_sg_tt_init(struct ttm_tt *ttm, struct ttm_buffer_object *bo, 181 uint32_t page_flags, enum ttm_caching caching) 182 { 183 int ret; 184 185 ttm_tt_init_fields(ttm, bo, page_flags, caching); 186 187 if (page_flags & TTM_PAGE_FLAG_SG) 188 ret = ttm_sg_tt_alloc_page_directory(ttm); 189 else 190 ret = ttm_dma_tt_alloc_page_directory(ttm); 191 if (ret) { 192 pr_err("Failed allocating page table\n"); 193 return -ENOMEM; 194 } 195 return 0; 196 } 197 EXPORT_SYMBOL(ttm_sg_tt_init); 198 199 int ttm_tt_swapin(struct ttm_tt *ttm) 200 { 201 struct address_space *swap_space; 202 struct file *swap_storage; 203 struct page *from_page; 204 struct page *to_page; 205 gfp_t gfp_mask; 206 int i, ret; 207 208 swap_storage = ttm->swap_storage; 209 BUG_ON(swap_storage == NULL); 210 211 swap_space = swap_storage->f_mapping; 212 gfp_mask = mapping_gfp_mask(swap_space); 213 214 for (i = 0; i < ttm->num_pages; ++i) { 215 from_page = shmem_read_mapping_page_gfp(swap_space, i, 216 gfp_mask); 217 if (IS_ERR(from_page)) { 218 ret = PTR_ERR(from_page); 219 goto out_err; 220 } 221 to_page = ttm->pages[i]; 222 if (unlikely(to_page == NULL)) { 223 ret = -ENOMEM; 224 goto out_err; 225 } 226 227 copy_highpage(to_page, from_page); 228 put_page(from_page); 229 } 230 231 fput(swap_storage); 232 ttm->swap_storage = NULL; 233 ttm->page_flags &= ~TTM_PAGE_FLAG_SWAPPED; 234 235 return 0; 236 237 out_err: 238 return ret; 239 } 240 241 /** 242 * ttm_tt_swapout - swap out tt object 243 * 244 * @bdev: TTM device structure. 245 * @ttm: The struct ttm_tt. 246 * @gfp_flags: Flags to use for memory allocation. 247 * 248 * Swapout a TT object to a shmem_file, return number of pages swapped out or 249 * negative error code. 250 */ 251 int ttm_tt_swapout(struct ttm_device *bdev, struct ttm_tt *ttm, 252 gfp_t gfp_flags) 253 { 254 loff_t size = (loff_t)ttm->num_pages << PAGE_SHIFT; 255 struct address_space *swap_space; 256 struct file *swap_storage; 257 struct page *from_page; 258 struct page *to_page; 259 int i, ret; 260 261 swap_storage = shmem_file_setup("ttm swap", size, 0); 262 if (IS_ERR(swap_storage)) { 263 pr_err("Failed allocating swap storage\n"); 264 return PTR_ERR(swap_storage); 265 } 266 267 swap_space = swap_storage->f_mapping; 268 gfp_flags &= mapping_gfp_mask(swap_space); 269 270 for (i = 0; i < ttm->num_pages; ++i) { 271 from_page = ttm->pages[i]; 272 if (unlikely(from_page == NULL)) 273 continue; 274 275 to_page = shmem_read_mapping_page_gfp(swap_space, i, gfp_flags); 276 if (IS_ERR(to_page)) { 277 ret = PTR_ERR(to_page); 278 goto out_err; 279 } 280 copy_highpage(to_page, from_page); 281 set_page_dirty(to_page); 282 mark_page_accessed(to_page); 283 put_page(to_page); 284 } 285 286 ttm_tt_unpopulate(bdev, ttm); 287 ttm->swap_storage = swap_storage; 288 ttm->page_flags |= TTM_PAGE_FLAG_SWAPPED; 289 290 return ttm->num_pages; 291 292 out_err: 293 fput(swap_storage); 294 295 return ret; 296 } 297 298 static void ttm_tt_add_mapping(struct ttm_device *bdev, struct ttm_tt *ttm) 299 { 300 pgoff_t i; 301 302 if (ttm->page_flags & TTM_PAGE_FLAG_SG) 303 return; 304 305 for (i = 0; i < ttm->num_pages; ++i) 306 ttm->pages[i]->mapping = bdev->dev_mapping; 307 } 308 309 int ttm_tt_populate(struct ttm_device *bdev, 310 struct ttm_tt *ttm, struct ttm_operation_ctx *ctx) 311 { 312 int ret; 313 314 if (!ttm) 315 return -EINVAL; 316 317 if (ttm_tt_is_populated(ttm)) 318 return 0; 319 320 if (!(ttm->page_flags & TTM_PAGE_FLAG_SG)) { 321 atomic_long_add(ttm->num_pages, &ttm_pages_allocated); 322 if (bdev->pool.use_dma32) 323 atomic_long_add(ttm->num_pages, 324 &ttm_dma32_pages_allocated); 325 } 326 327 while (atomic_long_read(&ttm_pages_allocated) > ttm_pages_limit || 328 atomic_long_read(&ttm_dma32_pages_allocated) > 329 ttm_dma32_pages_limit) { 330 331 ret = ttm_global_swapout(ctx, GFP_KERNEL); 332 if (ret == 0) 333 break; 334 if (ret < 0) 335 goto error; 336 } 337 338 if (bdev->funcs->ttm_tt_populate) 339 ret = bdev->funcs->ttm_tt_populate(bdev, ttm, ctx); 340 else 341 ret = ttm_pool_alloc(&bdev->pool, ttm, ctx); 342 if (ret) 343 goto error; 344 345 ttm_tt_add_mapping(bdev, ttm); 346 ttm->page_flags |= TTM_PAGE_FLAG_PRIV_POPULATED; 347 if (unlikely(ttm->page_flags & TTM_PAGE_FLAG_SWAPPED)) { 348 ret = ttm_tt_swapin(ttm); 349 if (unlikely(ret != 0)) { 350 ttm_tt_unpopulate(bdev, ttm); 351 return ret; 352 } 353 } 354 355 return 0; 356 357 error: 358 if (!(ttm->page_flags & TTM_PAGE_FLAG_SG)) { 359 atomic_long_sub(ttm->num_pages, &ttm_pages_allocated); 360 if (bdev->pool.use_dma32) 361 atomic_long_sub(ttm->num_pages, 362 &ttm_dma32_pages_allocated); 363 } 364 return ret; 365 } 366 EXPORT_SYMBOL(ttm_tt_populate); 367 368 static void ttm_tt_clear_mapping(struct ttm_tt *ttm) 369 { 370 pgoff_t i; 371 struct page **page = ttm->pages; 372 373 if (ttm->page_flags & TTM_PAGE_FLAG_SG) 374 return; 375 376 for (i = 0; i < ttm->num_pages; ++i) { 377 (*page)->mapping = NULL; 378 (*page++)->index = 0; 379 } 380 } 381 382 void ttm_tt_unpopulate(struct ttm_device *bdev, struct ttm_tt *ttm) 383 { 384 if (!ttm_tt_is_populated(ttm)) 385 return; 386 387 ttm_tt_clear_mapping(ttm); 388 if (bdev->funcs->ttm_tt_unpopulate) 389 bdev->funcs->ttm_tt_unpopulate(bdev, ttm); 390 else 391 ttm_pool_free(&bdev->pool, ttm); 392 393 if (!(ttm->page_flags & TTM_PAGE_FLAG_SG)) { 394 atomic_long_sub(ttm->num_pages, &ttm_pages_allocated); 395 if (bdev->pool.use_dma32) 396 atomic_long_sub(ttm->num_pages, 397 &ttm_dma32_pages_allocated); 398 } 399 400 ttm->page_flags &= ~TTM_PAGE_FLAG_PRIV_POPULATED; 401 } 402 403 /** 404 * ttm_tt_mgr_init - register with the MM shrinker 405 * 406 * Register with the MM shrinker for swapping out BOs. 407 */ 408 void ttm_tt_mgr_init(unsigned long num_pages, unsigned long num_dma32_pages) 409 { 410 if (!ttm_pages_limit) 411 ttm_pages_limit = num_pages; 412 413 if (!ttm_dma32_pages_limit) 414 ttm_dma32_pages_limit = num_dma32_pages; 415 } 416