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/vmalloc.h>
  32 #include <linux/sched.h>
  33 #include <linux/highmem.h>
  34 #include <linux/pagemap.h>
  35 #include <linux/file.h>
  36 #include <linux/swap.h>
  37 #include "ttm/ttm_module.h"
  38 #include "ttm/ttm_bo_driver.h"
  39 #include "ttm/ttm_placement.h"
  40
  41 static int ttm_tt_swapin(struct ttm_tt *ttm);
  42
  43 #if defined(CONFIG_X86)
  44 static void ttm_tt_clflush_page(struct page *page)
  45 {
  46         uint8_t *page_virtual;
  47         unsigned int i;
  48
  49         if (unlikely(page == NULL))
  50                 return;
  51
  52         page_virtual = kmap_atomic(page, KM_USER0);
  53
  54         for (i = 0; i < PAGE_SIZE; i += boot_cpu_data.x86_clflush_size)
  55                 clflush(page_virtual + i);
  56
  57         kunmap_atomic(page_virtual, KM_USER0);
  58 }
  59
  60 static void ttm_tt_cache_flush_clflush(struct page *pages[],
  61                                        unsigned long num_pages)
  62 {
  63         unsigned long i;
  64
  65         mb();
  66         for (i = 0; i < num_pages; ++i)
  67                 ttm_tt_clflush_page(*pages++);
  68         mb();
  69 }
  70 #elif !defined(__powerpc__)
  71 static void ttm_tt_ipi_handler(void *null)
  72 {
  73         ;
  74 }
  75 #endif
  76
  77 void ttm_tt_cache_flush(struct page *pages[], unsigned long num_pages)
  78 {
  79
  80 #if defined(CONFIG_X86)
  81         if (cpu_has_clflush) {
  82                 ttm_tt_cache_flush_clflush(pages, num_pages);
  83                 return;
  84         }
  85 #elif defined(__powerpc__)
  86         unsigned long i;
  87
  88         for (i = 0; i < num_pages; ++i) {
  89                 struct page *page = pages[i];
  90                 void *page_virtual;
  91
  92                 if (unlikely(page == NULL))
  93                         continue;
  94
  95                 page_virtual = kmap_atomic(page, KM_USER0);
  96                 flush_dcache_range((unsigned long) page_virtual,
  97                                    (unsigned long) page_virtual + PAGE_SIZE);
  98                 kunmap_atomic(page_virtual, KM_USER0);
  99         }
 100 #else
 101         if (on_each_cpu(ttm_tt_ipi_handler, NULL, 1) != 0)
 102                 printk(KERN_ERR TTM_PFX
 103                        "Timed out waiting for drm cache flush.\n");
 104 #endif
 105 }
 106
 107 /**
 108  * Allocates storage for pointers to the pages that back the ttm.
 109  *
 110  * Uses kmalloc if possible. Otherwise falls back to vmalloc.
 111  */
 112 static void ttm_tt_alloc_page_directory(struct ttm_tt *ttm)
 113 {
 114         unsigned long size = ttm->num_pages * sizeof(*ttm->pages);
 115         ttm->pages = NULL;
 116
 117         if (size <= PAGE_SIZE)
 118                 ttm->pages = kzalloc(size, GFP_KERNEL);
 119
 120         if (!ttm->pages) {
 121                 ttm->pages = vmalloc_user(size);
 122                 if (ttm->pages)
 123                         ttm->page_flags |= TTM_PAGE_FLAG_VMALLOC;
 124         }
 125 }
 126
 127 static void ttm_tt_free_page_directory(struct ttm_tt *ttm)
 128 {
 129         if (ttm->page_flags & TTM_PAGE_FLAG_VMALLOC) {
 130                 vfree(ttm->pages);
 131                 ttm->page_flags &= ~TTM_PAGE_FLAG_VMALLOC;
 132         } else {
 133                 kfree(ttm->pages);
 134         }
 135         ttm->pages = NULL;
 136 }
 137
 138 static struct page *ttm_tt_alloc_page(unsigned page_flags)
 139 {
 140         gfp_t gfp_flags = GFP_HIGHUSER;
 141
 142         if (page_flags & TTM_PAGE_FLAG_ZERO_ALLOC)
 143                 gfp_flags |= __GFP_ZERO;
 144
 145         if (page_flags & TTM_PAGE_FLAG_DMA32)
 146                 gfp_flags |= __GFP_DMA32;
 147
 148         return alloc_page(gfp_flags);
 149 }
 150
 151 static void ttm_tt_free_user_pages(struct ttm_tt *ttm)
 152 {
 153         int write;
 154         int dirty;
 155         struct page *page;
 156         int i;
 157         struct ttm_backend *be = ttm->be;
 158
 159         BUG_ON(!(ttm->page_flags & TTM_PAGE_FLAG_USER));
 160         write = ((ttm->page_flags & TTM_PAGE_FLAG_WRITE) != 0);
 161         dirty = ((ttm->page_flags & TTM_PAGE_FLAG_USER_DIRTY) != 0);
 162
 163         if (be)
 164                 be->func->clear(be);
 165
 166         for (i = 0; i < ttm->num_pages; ++i) {
 167                 page = ttm->pages[i];
 168                 if (page == NULL)
 169                         continue;
 170
 171                 if (page == ttm->dummy_read_page) {
 172                         BUG_ON(write);
 173                         continue;
 174                 }
 175
 176                 if (write && dirty && !PageReserved(page))
 177                         set_page_dirty_lock(page);
 178
 179                 ttm->pages[i] = NULL;
 180                 ttm_mem_global_free(ttm->bdev->mem_glob, PAGE_SIZE, false);
 181                 put_page(page);
 182         }
 183         ttm->state = tt_unpopulated;
 184         ttm->first_himem_page = ttm->num_pages;
 185         ttm->last_lomem_page = -1;
 186 }
 187
 188 static struct page *__ttm_tt_get_page(struct ttm_tt *ttm, int index)
 189 {
 190         struct page *p;
 191         struct ttm_bo_device *bdev = ttm->bdev;
 192         struct ttm_mem_global *mem_glob = bdev->mem_glob;
 193         int ret;
 194
 195         while (NULL == (p = ttm->pages[index])) {
 196                 p = ttm_tt_alloc_page(ttm->page_flags);
 197
 198                 if (!p)
 199                         return NULL;
 200
 201                 if (PageHighMem(p)) {
 202                         ret =
 203                             ttm_mem_global_alloc(mem_glob, PAGE_SIZE,
 204                                                  false, false, true);
 205                         if (unlikely(ret != 0))
 206                                 goto out_err;
 207                         ttm->pages[--ttm->first_himem_page] = p;
 208                 } else {
 209                         ret =
 210                             ttm_mem_global_alloc(mem_glob, PAGE_SIZE,
 211                                                  false, false, false);
 212                         if (unlikely(ret != 0))
 213                                 goto out_err;
 214                         ttm->pages[++ttm->last_lomem_page] = p;
 215                 }
 216         }
 217         return p;
 218 out_err:
 219         put_page(p);
 220         return NULL;
 221 }
 222
 223 struct page *ttm_tt_get_page(struct ttm_tt *ttm, int index)
 224 {
 225         int ret;
 226
 227         if (unlikely(ttm->page_flags & TTM_PAGE_FLAG_SWAPPED)) {
 228                 ret = ttm_tt_swapin(ttm);
 229                 if (unlikely(ret != 0))
 230                         return NULL;
 231         }
 232         return __ttm_tt_get_page(ttm, index);
 233 }
 234
 235 int ttm_tt_populate(struct ttm_tt *ttm)
 236 {
 237         struct page *page;
 238         unsigned long i;
 239         struct ttm_backend *be;
 240         int ret;
 241
 242         if (ttm->state != tt_unpopulated)
 243                 return 0;
 244
 245         if (unlikely(ttm->page_flags & TTM_PAGE_FLAG_SWAPPED)) {
 246                 ret = ttm_tt_swapin(ttm);
 247                 if (unlikely(ret != 0))
 248                         return ret;
 249         }
 250
 251         be = ttm->be;
 252
 253         for (i = 0; i < ttm->num_pages; ++i) {
 254                 page = __ttm_tt_get_page(ttm, i);
 255                 if (!page)
 256                         return -ENOMEM;
 257         }
 258
 259         be->func->populate(be, ttm->num_pages, ttm->pages,
 260                            ttm->dummy_read_page);
 261         ttm->state = tt_unbound;
 262         return 0;
 263 }
 264
 265 #ifdef CONFIG_X86
 266 static inline int ttm_tt_set_page_caching(struct page *p,
 267                                           enum ttm_caching_state c_state)
 268 {
 269         if (PageHighMem(p))
 270                 return 0;
 271
 272         switch (c_state) {
 273         case tt_cached:
 274                 return set_pages_wb(p, 1);
 275         case tt_wc:
 276             return set_memory_wc((unsigned long) page_address(p), 1);
 277         default:
 278                 return set_pages_uc(p, 1);
 279         }
 280 }
 281 #else /* CONFIG_X86 */
 282 static inline int ttm_tt_set_page_caching(struct page *p,
 283                                           enum ttm_caching_state c_state)
 284 {
 285         return 0;
 286 }
 287 #endif /* CONFIG_X86 */
 288
 289 /*
 290  * Change caching policy for the linear kernel map
 291  * for range of pages in a ttm.
 292  */
 293
 294 static int ttm_tt_set_caching(struct ttm_tt *ttm,
 295                               enum ttm_caching_state c_state)
 296 {
 297         int i, j;
 298         struct page *cur_page;
 299         int ret;
 300
 301         if (ttm->caching_state == c_state)
 302                 return 0;
 303
 304         if (c_state != tt_cached) {
 305                 ret = ttm_tt_populate(ttm);
 306                 if (unlikely(ret != 0))
 307                         return ret;
 308         }
 309
 310         if (ttm->caching_state == tt_cached)
 311                 ttm_tt_cache_flush(ttm->pages, ttm->num_pages);
 312
 313         for (i = 0; i < ttm->num_pages; ++i) {
 314                 cur_page = ttm->pages[i];
 315                 if (likely(cur_page != NULL)) {
 316                         ret = ttm_tt_set_page_caching(cur_page, c_state);
 317                         if (unlikely(ret != 0))
 318                                 goto out_err;
 319                 }
 320         }
 321
 322         ttm->caching_state = c_state;
 323
 324         return 0;
 325
 326 out_err:
 327         for (j = 0; j < i; ++j) {
 328                 cur_page = ttm->pages[j];
 329                 if (likely(cur_page != NULL)) {
 330                         (void)ttm_tt_set_page_caching(cur_page,
 331                                                       ttm->caching_state);
 332                 }
 333         }
 334
 335         return ret;
 336 }
 337
 338 int ttm_tt_set_placement_caching(struct ttm_tt *ttm, uint32_t placement)
 339 {
 340         enum ttm_caching_state state;
 341
 342         if (placement & TTM_PL_FLAG_WC)
 343                 state = tt_wc;
 344         else if (placement & TTM_PL_FLAG_UNCACHED)
 345                 state = tt_uncached;
 346         else
 347                 state = tt_cached;
 348
 349         return ttm_tt_set_caching(ttm, state);
 350 }
 351
 352 static void ttm_tt_free_alloced_pages(struct ttm_tt *ttm)
 353 {
 354         int i;
 355         struct page *cur_page;
 356         struct ttm_backend *be = ttm->be;
 357
 358         if (be)
 359                 be->func->clear(be);
 360         (void)ttm_tt_set_caching(ttm, tt_cached);
 361         for (i = 0; i < ttm->num_pages; ++i) {
 362                 cur_page = ttm->pages[i];
 363                 ttm->pages[i] = NULL;
 364                 if (cur_page) {
 365                         if (page_count(cur_page) != 1)
 366                                 printk(KERN_ERR TTM_PFX
 367                                        "Erroneous page count. "
 368                                        "Leaking pages.\n");
 369                         ttm_mem_global_free(ttm->bdev->mem_glob, PAGE_SIZE,
 370                                             PageHighMem(cur_page));
 371                         __free_page(cur_page);
 372                 }
 373         }
 374         ttm->state = tt_unpopulated;
 375         ttm->first_himem_page = ttm->num_pages;
 376         ttm->last_lomem_page = -1;
 377 }
 378
 379 void ttm_tt_destroy(struct ttm_tt *ttm)
 380 {
 381         struct ttm_backend *be;
 382
 383         if (unlikely(ttm == NULL))
 384                 return;
 385
 386         be = ttm->be;
 387         if (likely(be != NULL)) {
 388                 be->func->destroy(be);
 389                 ttm->be = NULL;
 390         }
 391
 392         if (likely(ttm->pages != NULL)) {
 393                 if (ttm->page_flags & TTM_PAGE_FLAG_USER)
 394                         ttm_tt_free_user_pages(ttm);
 395                 else
 396                         ttm_tt_free_alloced_pages(ttm);
 397
 398                 ttm_tt_free_page_directory(ttm);
 399         }
 400
 401         if (!(ttm->page_flags & TTM_PAGE_FLAG_PERSISTANT_SWAP) &&
 402             ttm->swap_storage)
 403                 fput(ttm->swap_storage);
 404
 405         kfree(ttm);
 406 }
 407
 408 int ttm_tt_set_user(struct ttm_tt *ttm,
 409                     struct task_struct *tsk,
 410                     unsigned long start, unsigned long num_pages)
 411 {
 412         struct mm_struct *mm = tsk->mm;
 413         int ret;
 414         int write = (ttm->page_flags & TTM_PAGE_FLAG_WRITE) != 0;
 415         struct ttm_mem_global *mem_glob = ttm->bdev->mem_glob;
 416
 417         BUG_ON(num_pages != ttm->num_pages);
 418         BUG_ON((ttm->page_flags & TTM_PAGE_FLAG_USER) == 0);
 419
 420         /**
 421          * Account user pages as lowmem pages for now.
 422          */
 423
 424         ret = ttm_mem_global_alloc(mem_glob, num_pages * PAGE_SIZE,
 425                                    false, false, false);
 426         if (unlikely(ret != 0))
 427                 return ret;
 428
 429         down_read(&mm->mmap_sem);
 430         ret = get_user_pages(tsk, mm, start, num_pages,
 431                              write, 0, ttm->pages, NULL);
 432         up_read(&mm->mmap_sem);
 433
 434         if (ret != num_pages && write) {
 435                 ttm_tt_free_user_pages(ttm);
 436                 ttm_mem_global_free(mem_glob, num_pages * PAGE_SIZE, false);
 437                 return -ENOMEM;
 438         }
 439
 440         ttm->tsk = tsk;
 441         ttm->start = start;
 442         ttm->state = tt_unbound;
 443
 444         return 0;
 445 }
 446
 447 struct ttm_tt *ttm_tt_create(struct ttm_bo_device *bdev, unsigned long size,
 448                              uint32_t page_flags, struct page *dummy_read_page)
 449 {
 450         struct ttm_bo_driver *bo_driver = bdev->driver;
 451         struct ttm_tt *ttm;
 452
 453         if (!bo_driver)
 454                 return NULL;
 455
 456         ttm = kzalloc(sizeof(*ttm), GFP_KERNEL);
 457         if (!ttm)
 458                 return NULL;
 459
 460         ttm->bdev = bdev;
 461
 462         ttm->num_pages = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
 463         ttm->first_himem_page = ttm->num_pages;
 464         ttm->last_lomem_page = -1;
 465         ttm->caching_state = tt_cached;
 466         ttm->page_flags = page_flags;
 467
 468         ttm->dummy_read_page = dummy_read_page;
 469
 470         ttm_tt_alloc_page_directory(ttm);
 471         if (!ttm->pages) {
 472                 ttm_tt_destroy(ttm);
 473                 printk(KERN_ERR TTM_PFX "Failed allocating page table\n");
 474                 return NULL;
 475         }
 476         ttm->be = bo_driver->create_ttm_backend_entry(bdev);
 477         if (!ttm->be) {
 478                 ttm_tt_destroy(ttm);
 479                 printk(KERN_ERR TTM_PFX "Failed creating ttm backend entry\n");
 480                 return NULL;
 481         }
 482         ttm->state = tt_unpopulated;
 483         return ttm;
 484 }
 485
 486 void ttm_tt_unbind(struct ttm_tt *ttm)
 487 {
 488         int ret;
 489         struct ttm_backend *be = ttm->be;
 490
 491         if (ttm->state == tt_bound) {
 492                 ret = be->func->unbind(be);
 493                 BUG_ON(ret);
 494                 ttm->state = tt_unbound;
 495         }
 496 }
 497
 498 int ttm_tt_bind(struct ttm_tt *ttm, struct ttm_mem_reg *bo_mem)
 499 {
 500         int ret = 0;
 501         struct ttm_backend *be;
 502
 503         if (!ttm)
 504                 return -EINVAL;
 505
 506         if (ttm->state == tt_bound)
 507                 return 0;
 508
 509         be = ttm->be;
 510
 511         ret = ttm_tt_populate(ttm);
 512         if (ret)
 513                 return ret;
 514
 515         ret = be->func->bind(be, bo_mem);
 516         if (ret) {
 517                 printk(KERN_ERR TTM_PFX "Couldn't bind backend.\n");
 518                 return ret;
 519         }
 520
 521         ttm->state = tt_bound;
 522
 523         if (ttm->page_flags & TTM_PAGE_FLAG_USER)
 524                 ttm->page_flags |= TTM_PAGE_FLAG_USER_DIRTY;
 525         return 0;
 526 }
 527 EXPORT_SYMBOL(ttm_tt_bind);
 528
 529 static int ttm_tt_swapin(struct ttm_tt *ttm)
 530 {
 531         struct address_space *swap_space;
 532         struct file *swap_storage;
 533         struct page *from_page;
 534         struct page *to_page;
 535         void *from_virtual;
 536         void *to_virtual;
 537         int i;
 538         int ret;
 539
 540         if (ttm->page_flags & TTM_PAGE_FLAG_USER) {
 541                 ret = ttm_tt_set_user(ttm, ttm->tsk, ttm->start,
 542                                       ttm->num_pages);
 543                 if (unlikely(ret != 0))
 544                         return ret;
 545
 546                 ttm->page_flags &= ~TTM_PAGE_FLAG_SWAPPED;
 547                 return 0;
 548         }
 549
 550         swap_storage = ttm->swap_storage;
 551         BUG_ON(swap_storage == NULL);
 552
 553         swap_space = swap_storage->f_path.dentry->d_inode->i_mapping;
 554
 555         for (i = 0; i < ttm->num_pages; ++i) {
 556                 from_page = read_mapping_page(swap_space, i, NULL);
 557                 if (IS_ERR(from_page))
 558                         goto out_err;
 559                 to_page = __ttm_tt_get_page(ttm, i);
 560                 if (unlikely(to_page == NULL))
 561                         goto out_err;
 562
 563                 preempt_disable();
 564                 from_virtual = kmap_atomic(from_page, KM_USER0);
 565                 to_virtual = kmap_atomic(to_page, KM_USER1);
 566                 memcpy(to_virtual, from_virtual, PAGE_SIZE);
 567                 kunmap_atomic(to_virtual, KM_USER1);
 568                 kunmap_atomic(from_virtual, KM_USER0);
 569                 preempt_enable();
 570                 page_cache_release(from_page);
 571         }
 572
 573         if (!(ttm->page_flags & TTM_PAGE_FLAG_PERSISTANT_SWAP))
 574                 fput(swap_storage);
 575         ttm->swap_storage = NULL;
 576         ttm->page_flags &= ~TTM_PAGE_FLAG_SWAPPED;
 577
 578         return 0;
 579 out_err:
 580         ttm_tt_free_alloced_pages(ttm);
 581         return -ENOMEM;
 582 }
 583
 584 int ttm_tt_swapout(struct ttm_tt *ttm, struct file *persistant_swap_storage)
 585 {
 586         struct address_space *swap_space;
 587         struct file *swap_storage;
 588         struct page *from_page;
 589         struct page *to_page;
 590         void *from_virtual;
 591         void *to_virtual;
 592         int i;
 593
 594         BUG_ON(ttm->state != tt_unbound && ttm->state != tt_unpopulated);
 595         BUG_ON(ttm->caching_state != tt_cached);
 596
 597         /*
 598          * For user buffers, just unpin the pages, as there should be
 599          * vma references.
 600          */
 601
 602         if (ttm->page_flags & TTM_PAGE_FLAG_USER) {
 603                 ttm_tt_free_user_pages(ttm);
 604                 ttm->page_flags |= TTM_PAGE_FLAG_SWAPPED;
 605                 ttm->swap_storage = NULL;
 606                 return 0;
 607         }
 608
 609         if (!persistant_swap_storage) {
 610                 swap_storage = shmem_file_setup("ttm swap",
 611                                                 ttm->num_pages << PAGE_SHIFT,
 612                                                 0);
 613                 if (unlikely(IS_ERR(swap_storage))) {
 614                         printk(KERN_ERR "Failed allocating swap storage.\n");
 615                         return -ENOMEM;
 616                 }
 617         } else
 618                 swap_storage = persistant_swap_storage;
 619
 620         swap_space = swap_storage->f_path.dentry->d_inode->i_mapping;
 621
 622         for (i = 0; i < ttm->num_pages; ++i) {
 623                 from_page = ttm->pages[i];
 624                 if (unlikely(from_page == NULL))
 625                         continue;
 626                 to_page = read_mapping_page(swap_space, i, NULL);
 627                 if (unlikely(to_page == NULL))
 628                         goto out_err;
 629
 630                 preempt_disable();
 631                 from_virtual = kmap_atomic(from_page, KM_USER0);
 632                 to_virtual = kmap_atomic(to_page, KM_USER1);
 633                 memcpy(to_virtual, from_virtual, PAGE_SIZE);
 634                 kunmap_atomic(to_virtual, KM_USER1);
 635                 kunmap_atomic(from_virtual, KM_USER0);
 636                 preempt_enable();
 637                 set_page_dirty(to_page);
 638                 mark_page_accessed(to_page);
 639                 page_cache_release(to_page);
 640         }
 641
 642         ttm_tt_free_alloced_pages(ttm);
 643         ttm->swap_storage = swap_storage;
 644         ttm->page_flags |= TTM_PAGE_FLAG_SWAPPED;
 645         if (persistant_swap_storage)
 646                 ttm->page_flags |= TTM_PAGE_FLAG_PERSISTANT_SWAP;
 647
 648         return 0;
 649 out_err:
 650         if (!persistant_swap_storage)
 651                 fput(swap_storage);
 652
 653         return -ENOMEM;
 654 }