drivers/gpu/drm/ttm/ttm_tt.c

   1 /**************************************************************************
   2  *
   3  * Copyright (c) 2006-2009 VMware, Inc., Palo Alto, CA., USA
   4  * All Rights Reserved.
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a
   7  * copy of this software and associated documentation files (the
   8  * "Software"), to deal in the Software without restriction, including
   9  * without limitation the rights to use, copy, modify, merge, publish,
  10  * distribute, sub license, and/or sell copies of the Software, and to
  11  * permit persons to whom the Software is furnished to do so, subject to
  12  * the following conditions:
  13  *
  14  * The above copyright notice and this permission notice (including the
  15  * next paragraph) shall be included in all copies or substantial portions
  16  * of the Software.
  17  *
  18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  19  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  20  * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
  21  * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
  22  * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
  23  * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
  24  * USE OR OTHER DEALINGS IN THE SOFTWARE.
  25  *
  26  **************************************************************************/
  27 /*
  28  * Authors: Thomas Hellstrom <thellstrom-at-vmware-dot-com>
  29  */
  30
  31 #include <linux/sched.h>
  32 #include <linux/highmem.h>
  33 #include <linux/pagemap.h>
  34 #include <linux/shmem_fs.h>
  35 #include <linux/file.h>
  36 #include <linux/swap.h>
  37 #include <linux/slab.h>
  38 #include <linux/export.h>
  39 #include "drm_cache.h"
  40 #include "drm_mem_util.h"
  41 #include "ttm/ttm_module.h"
  42 #include "ttm/ttm_bo_driver.h"
  43 #include "ttm/ttm_placement.h"
  44 #include "ttm/ttm_page_alloc.h"
  45
  46 static int ttm_tt_swapin(struct ttm_tt *ttm);
  47
  48 /**
  49  * Allocates storage for pointers to the pages that back the ttm.
  50  */
  51 static void ttm_tt_alloc_page_directory(struct ttm_tt *ttm)
  52 {
  53         ttm->pages = drm_calloc_large(ttm->num_pages, sizeof(*ttm->pages));
  54         ttm->dma_address = drm_calloc_large(ttm->num_pages,
  55                                             sizeof(*ttm->dma_address));
  56 }
  57
  58 static void ttm_tt_free_page_directory(struct ttm_tt *ttm)
  59 {
  60         drm_free_large(ttm->pages);
  61         ttm->pages = NULL;
  62         drm_free_large(ttm->dma_address);
  63         ttm->dma_address = NULL;
  64 }
  65
  66 static void ttm_tt_free_user_pages(struct ttm_tt *ttm)
  67 {
  68         int write;
  69         int dirty;
  70         struct page *page;
  71         int i;
  72         struct ttm_backend *be = ttm->be;
  73
  74         BUG_ON(!(ttm->page_flags & TTM_PAGE_FLAG_USER));
  75         write = ((ttm->page_flags & TTM_PAGE_FLAG_WRITE) != 0);
  76         dirty = ((ttm->page_flags & TTM_PAGE_FLAG_USER_DIRTY) != 0);
  77
  78         if (be)
  79                 be->func->clear(be);
  80
  81         for (i = 0; i < ttm->num_pages; ++i) {
  82                 page = ttm->pages[i];
  83                 if (page == NULL)
  84                         continue;
  85
  86                 if (page == ttm->dummy_read_page) {
  87                         BUG_ON(write);
  88                         continue;
  89                 }
  90
  91                 if (write && dirty && !PageReserved(page))
  92                         set_page_dirty_lock(page);
  93
  94                 ttm->pages[i] = NULL;
  95                 ttm_mem_global_free(ttm->glob->mem_glob, PAGE_SIZE);
  96                 put_page(page);
  97         }
  98         ttm->state = tt_unpopulated;
  99         ttm->first_himem_page = ttm->num_pages;
 100         ttm->last_lomem_page = -1;
 101 }
 102
 103 static struct page *__ttm_tt_get_page(struct ttm_tt *ttm, int index)
 104 {
 105         struct page *p;
 106         struct list_head h;
 107         struct ttm_mem_global *mem_glob = ttm->glob->mem_glob;
 108         int ret;
 109
 110         while (NULL == (p = ttm->pages[index])) {
 111
 112                 INIT_LIST_HEAD(&h);
 113
 114                 ret = ttm_get_pages(&h, ttm->page_flags, ttm->caching_state, 1,
 115                                     &ttm->dma_address[index]);
 116
 117                 if (ret != 0)
 118                         return NULL;
 119
 120                 p = list_first_entry(&h, struct page, lru);
 121
 122                 ret = ttm_mem_global_alloc_page(mem_glob, p, false, false);
 123                 if (unlikely(ret != 0))
 124                         goto out_err;
 125
 126                 if (PageHighMem(p))
 127                         ttm->pages[--ttm->first_himem_page] = p;
 128                 else
 129                         ttm->pages[++ttm->last_lomem_page] = p;
 130         }
 131         return p;
 132 out_err:
 133         put_page(p);
 134         return NULL;
 135 }
 136
 137 struct page *ttm_tt_get_page(struct ttm_tt *ttm, int index)
 138 {
 139         int ret;
 140
 141         if (unlikely(ttm->page_flags & TTM_PAGE_FLAG_SWAPPED)) {
 142                 ret = ttm_tt_swapin(ttm);
 143                 if (unlikely(ret != 0))
 144                         return NULL;
 145         }
 146         return __ttm_tt_get_page(ttm, index);
 147 }
 148
 149 int ttm_tt_populate(struct ttm_tt *ttm)
 150 {
 151         struct page *page;
 152         unsigned long i;
 153         struct ttm_backend *be;
 154         int ret;
 155
 156         if (ttm->state != tt_unpopulated)
 157                 return 0;
 158
 159         if (unlikely(ttm->page_flags & TTM_PAGE_FLAG_SWAPPED)) {
 160                 ret = ttm_tt_swapin(ttm);
 161                 if (unlikely(ret != 0))
 162                         return ret;
 163         }
 164
 165         be = ttm->be;
 166
 167         for (i = 0; i < ttm->num_pages; ++i) {
 168                 page = __ttm_tt_get_page(ttm, i);
 169                 if (!page)
 170                         return -ENOMEM;
 171         }
 172
 173         be->func->populate(be, ttm->num_pages, ttm->pages,
 174                            ttm->dummy_read_page, ttm->dma_address);
 175         ttm->state = tt_unbound;
 176         return 0;
 177 }
 178 EXPORT_SYMBOL(ttm_tt_populate);
 179
 180 #ifdef CONFIG_X86
 181 static inline int ttm_tt_set_page_caching(struct page *p,
 182                                           enum ttm_caching_state c_old,
 183                                           enum ttm_caching_state c_new)
 184 {
 185         int ret = 0;
 186
 187         if (PageHighMem(p))
 188                 return 0;
 189
 190         if (c_old != tt_cached) {
 191                 /* p isn't in the default caching state, set it to
 192                  * writeback first to free its current memtype. */
 193
 194                 ret = set_pages_wb(p, 1);
 195                 if (ret)
 196                         return ret;
 197         }
 198
 199         if (c_new == tt_wc)
 200                 ret = set_memory_wc((unsigned long) page_address(p), 1);
 201         else if (c_new == tt_uncached)
 202                 ret = set_pages_uc(p, 1);
 203
 204         return ret;
 205 }
 206 #else /* CONFIG_X86 */
 207 static inline int ttm_tt_set_page_caching(struct page *p,
 208                                           enum ttm_caching_state c_old,
 209                                           enum ttm_caching_state c_new)
 210 {
 211         return 0;
 212 }
 213 #endif /* CONFIG_X86 */
 214
 215 /*
 216  * Change caching policy for the linear kernel map
 217  * for range of pages in a ttm.
 218  */
 219
 220 static int ttm_tt_set_caching(struct ttm_tt *ttm,
 221                               enum ttm_caching_state c_state)
 222 {
 223         int i, j;
 224         struct page *cur_page;
 225         int ret;
 226
 227         if (ttm->caching_state == c_state)
 228                 return 0;
 229
 230         if (ttm->state == tt_unpopulated) {
 231                 /* Change caching but don't populate */
 232                 ttm->caching_state = c_state;
 233                 return 0;
 234         }
 235
 236         if (ttm->caching_state == tt_cached)
 237                 drm_clflush_pages(ttm->pages, ttm->num_pages);
 238
 239         for (i = 0; i < ttm->num_pages; ++i) {
 240                 cur_page = ttm->pages[i];
 241                 if (likely(cur_page != NULL)) {
 242                         ret = ttm_tt_set_page_caching(cur_page,
 243                                                       ttm->caching_state,
 244                                                       c_state);
 245                         if (unlikely(ret != 0))
 246                                 goto out_err;
 247                 }
 248         }
 249
 250         ttm->caching_state = c_state;
 251
 252         return 0;
 253
 254 out_err:
 255         for (j = 0; j < i; ++j) {
 256                 cur_page = ttm->pages[j];
 257                 if (likely(cur_page != NULL)) {
 258                         (void)ttm_tt_set_page_caching(cur_page, c_state,
 259                                                       ttm->caching_state);
 260                 }
 261         }
 262
 263         return ret;
 264 }
 265
 266 int ttm_tt_set_placement_caching(struct ttm_tt *ttm, uint32_t placement)
 267 {
 268         enum ttm_caching_state state;
 269
 270         if (placement & TTM_PL_FLAG_WC)
 271                 state = tt_wc;
 272         else if (placement & TTM_PL_FLAG_UNCACHED)
 273                 state = tt_uncached;
 274         else
 275                 state = tt_cached;
 276
 277         return ttm_tt_set_caching(ttm, state);
 278 }
 279 EXPORT_SYMBOL(ttm_tt_set_placement_caching);
 280
 281 static void ttm_tt_free_alloced_pages(struct ttm_tt *ttm)
 282 {
 283         int i;
 284         unsigned count = 0;
 285         struct list_head h;
 286         struct page *cur_page;
 287         struct ttm_backend *be = ttm->be;
 288
 289         INIT_LIST_HEAD(&h);
 290
 291         if (be)
 292                 be->func->clear(be);
 293         for (i = 0; i < ttm->num_pages; ++i) {
 294
 295                 cur_page = ttm->pages[i];
 296                 ttm->pages[i] = NULL;
 297                 if (cur_page) {
 298                         if (page_count(cur_page) != 1)
 299                                 printk(KERN_ERR TTM_PFX
 300                                        "Erroneous page count. "
 301                                        "Leaking pages.\n");
 302                         ttm_mem_global_free_page(ttm->glob->mem_glob,
 303                                                  cur_page);
 304                         list_add(&cur_page->lru, &h);
 305                         count++;
 306                 }
 307         }
 308         ttm_put_pages(&h, count, ttm->page_flags, ttm->caching_state,
 309                       ttm->dma_address);
 310         ttm->state = tt_unpopulated;
 311         ttm->first_himem_page = ttm->num_pages;
 312         ttm->last_lomem_page = -1;
 313 }
 314
 315 void ttm_tt_destroy(struct ttm_tt *ttm)
 316 {
 317         struct ttm_backend *be;
 318
 319         if (unlikely(ttm == NULL))
 320                 return;
 321
 322         be = ttm->be;
 323         if (likely(be != NULL)) {
 324                 be->func->destroy(be);
 325                 ttm->be = NULL;
 326         }
 327
 328         if (likely(ttm->pages != NULL)) {
 329                 if (ttm->page_flags & TTM_PAGE_FLAG_USER)
 330                         ttm_tt_free_user_pages(ttm);
 331                 else
 332                         ttm_tt_free_alloced_pages(ttm);
 333
 334                 ttm_tt_free_page_directory(ttm);
 335         }
 336
 337         if (!(ttm->page_flags & TTM_PAGE_FLAG_PERSISTENT_SWAP) &&
 338             ttm->swap_storage)
 339                 fput(ttm->swap_storage);
 340
 341         kfree(ttm);
 342 }
 343
 344 int ttm_tt_set_user(struct ttm_tt *ttm,
 345                     struct task_struct *tsk,
 346                     unsigned long start, unsigned long num_pages)
 347 {
 348         struct mm_struct *mm = tsk->mm;
 349         int ret;
 350         int write = (ttm->page_flags & TTM_PAGE_FLAG_WRITE) != 0;
 351         struct ttm_mem_global *mem_glob = ttm->glob->mem_glob;
 352
 353         BUG_ON(num_pages != ttm->num_pages);
 354         BUG_ON((ttm->page_flags & TTM_PAGE_FLAG_USER) == 0);
 355
 356         /**
 357          * Account user pages as lowmem pages for now.
 358          */
 359
 360         ret = ttm_mem_global_alloc(mem_glob, num_pages * PAGE_SIZE,
 361                                    false, false);
 362         if (unlikely(ret != 0))
 363                 return ret;
 364
 365         down_read(&mm->mmap_sem);
 366         ret = get_user_pages(tsk, mm, start, num_pages,
 367                              write, 0, ttm->pages, NULL);
 368         up_read(&mm->mmap_sem);
 369
 370         if (ret != num_pages && write) {
 371                 ttm_tt_free_user_pages(ttm);
 372                 ttm_mem_global_free(mem_glob, num_pages * PAGE_SIZE);
 373                 return -ENOMEM;
 374         }
 375
 376         ttm->tsk = tsk;
 377         ttm->start = start;
 378         ttm->state = tt_unbound;
 379
 380         return 0;
 381 }
 382
 383 struct ttm_tt *ttm_tt_create(struct ttm_bo_device *bdev, unsigned long size,
 384                              uint32_t page_flags, struct page *dummy_read_page)
 385 {
 386         struct ttm_bo_driver *bo_driver = bdev->driver;
 387         struct ttm_tt *ttm;
 388
 389         if (!bo_driver)
 390                 return NULL;
 391
 392         ttm = kzalloc(sizeof(*ttm), GFP_KERNEL);
 393         if (!ttm)
 394                 return NULL;
 395
 396         ttm->glob = bdev->glob;
 397         ttm->num_pages = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
 398         ttm->first_himem_page = ttm->num_pages;
 399         ttm->last_lomem_page = -1;
 400         ttm->caching_state = tt_cached;
 401         ttm->page_flags = page_flags;
 402
 403         ttm->dummy_read_page = dummy_read_page;
 404
 405         ttm_tt_alloc_page_directory(ttm);
 406         if (!ttm->pages) {
 407                 ttm_tt_destroy(ttm);
 408                 printk(KERN_ERR TTM_PFX "Failed allocating page table\n");
 409                 return NULL;
 410         }
 411         ttm->be = bo_driver->create_ttm_backend_entry(bdev);
 412         if (!ttm->be) {
 413                 ttm_tt_destroy(ttm);
 414                 printk(KERN_ERR TTM_PFX "Failed creating ttm backend entry\n");
 415                 return NULL;
 416         }
 417         ttm->state = tt_unpopulated;
 418         return ttm;
 419 }
 420
 421 void ttm_tt_unbind(struct ttm_tt *ttm)
 422 {
 423         int ret;
 424         struct ttm_backend *be = ttm->be;
 425
 426         if (ttm->state == tt_bound) {
 427                 ret = be->func->unbind(be);
 428                 BUG_ON(ret);
 429                 ttm->state = tt_unbound;
 430         }
 431 }
 432
 433 int ttm_tt_bind(struct ttm_tt *ttm, struct ttm_mem_reg *bo_mem)
 434 {
 435         int ret = 0;
 436         struct ttm_backend *be;
 437
 438         if (!ttm)
 439                 return -EINVAL;
 440
 441         if (ttm->state == tt_bound)
 442                 return 0;
 443
 444         be = ttm->be;
 445
 446         ret = ttm_tt_populate(ttm);
 447         if (ret)
 448                 return ret;
 449
 450         ret = be->func->bind(be, bo_mem);
 451         if (unlikely(ret != 0))
 452                 return ret;
 453
 454         ttm->state = tt_bound;
 455
 456         if (ttm->page_flags & TTM_PAGE_FLAG_USER)
 457                 ttm->page_flags |= TTM_PAGE_FLAG_USER_DIRTY;
 458         return 0;
 459 }
 460 EXPORT_SYMBOL(ttm_tt_bind);
 461
 462 static int ttm_tt_swapin(struct ttm_tt *ttm)
 463 {
 464         struct address_space *swap_space;
 465         struct file *swap_storage;
 466         struct page *from_page;
 467         struct page *to_page;
 468         void *from_virtual;
 469         void *to_virtual;
 470         int i;
 471         int ret = -ENOMEM;
 472
 473         if (ttm->page_flags & TTM_PAGE_FLAG_USER) {
 474                 ret = ttm_tt_set_user(ttm, ttm->tsk, ttm->start,
 475                                       ttm->num_pages);
 476                 if (unlikely(ret != 0))
 477                         return ret;
 478
 479                 ttm->page_flags &= ~TTM_PAGE_FLAG_SWAPPED;
 480                 return 0;
 481         }
 482
 483         swap_storage = ttm->swap_storage;
 484         BUG_ON(swap_storage == NULL);
 485
 486         swap_space = swap_storage->f_path.dentry->d_inode->i_mapping;
 487
 488         for (i = 0; i < ttm->num_pages; ++i) {
 489                 from_page = shmem_read_mapping_page(swap_space, i);
 490                 if (IS_ERR(from_page)) {
 491                         ret = PTR_ERR(from_page);
 492                         goto out_err;
 493                 }
 494                 to_page = __ttm_tt_get_page(ttm, i);
 495                 if (unlikely(to_page == NULL))
 496                         goto out_err;
 497
 498                 preempt_disable();
 499                 from_virtual = kmap_atomic(from_page, KM_USER0);
 500                 to_virtual = kmap_atomic(to_page, KM_USER1);
 501                 memcpy(to_virtual, from_virtual, PAGE_SIZE);
 502                 kunmap_atomic(to_virtual, KM_USER1);
 503                 kunmap_atomic(from_virtual, KM_USER0);
 504                 preempt_enable();
 505                 page_cache_release(from_page);
 506         }
 507
 508         if (!(ttm->page_flags & TTM_PAGE_FLAG_PERSISTENT_SWAP))
 509                 fput(swap_storage);
 510         ttm->swap_storage = NULL;
 511         ttm->page_flags &= ~TTM_PAGE_FLAG_SWAPPED;
 512
 513         return 0;
 514 out_err:
 515         ttm_tt_free_alloced_pages(ttm);
 516         return ret;
 517 }
 518
 519 int ttm_tt_swapout(struct ttm_tt *ttm, struct file *persistent_swap_storage)
 520 {
 521         struct address_space *swap_space;
 522         struct file *swap_storage;
 523         struct page *from_page;
 524         struct page *to_page;
 525         void *from_virtual;
 526         void *to_virtual;
 527         int i;
 528         int ret = -ENOMEM;
 529
 530         BUG_ON(ttm->state != tt_unbound && ttm->state != tt_unpopulated);
 531         BUG_ON(ttm->caching_state != tt_cached);
 532
 533         /*
 534          * For user buffers, just unpin the pages, as there should be
 535          * vma references.
 536          */
 537
 538         if (ttm->page_flags & TTM_PAGE_FLAG_USER) {
 539                 ttm_tt_free_user_pages(ttm);
 540                 ttm->page_flags |= TTM_PAGE_FLAG_SWAPPED;
 541                 ttm->swap_storage = NULL;
 542                 return 0;
 543         }
 544
 545         if (!persistent_swap_storage) {
 546                 swap_storage = shmem_file_setup("ttm swap",
 547                                                 ttm->num_pages << PAGE_SHIFT,
 548                                                 0);
 549                 if (unlikely(IS_ERR(swap_storage))) {
 550                         printk(KERN_ERR "Failed allocating swap storage.\n");
 551                         return PTR_ERR(swap_storage);
 552                 }
 553         } else
 554                 swap_storage = persistent_swap_storage;
 555
 556         swap_space = swap_storage->f_path.dentry->d_inode->i_mapping;
 557
 558         for (i = 0; i < ttm->num_pages; ++i) {
 559                 from_page = ttm->pages[i];
 560                 if (unlikely(from_page == NULL))
 561                         continue;
 562                 to_page = shmem_read_mapping_page(swap_space, i);
 563                 if (unlikely(IS_ERR(to_page))) {
 564                         ret = PTR_ERR(to_page);
 565                         goto out_err;
 566                 }
 567                 preempt_disable();
 568                 from_virtual = kmap_atomic(from_page, KM_USER0);
 569                 to_virtual = kmap_atomic(to_page, KM_USER1);
 570                 memcpy(to_virtual, from_virtual, PAGE_SIZE);
 571                 kunmap_atomic(to_virtual, KM_USER1);
 572                 kunmap_atomic(from_virtual, KM_USER0);
 573                 preempt_enable();
 574                 set_page_dirty(to_page);
 575                 mark_page_accessed(to_page);
 576                 page_cache_release(to_page);
 577         }
 578
 579         ttm_tt_free_alloced_pages(ttm);
 580         ttm->swap_storage = swap_storage;
 581         ttm->page_flags |= TTM_PAGE_FLAG_SWAPPED;
 582         if (persistent_swap_storage)
 583                 ttm->page_flags |= TTM_PAGE_FLAG_PERSISTENT_SWAP;
 584
 585         return 0;
 586 out_err:
 587         if (!persistent_swap_storage)
 588                 fput(swap_storage);
 589
 590         return ret;
 591 }