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_USER;
 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         else
 148                 gfp_flags |= __GFP_HIGHMEM;
 149
 150         return alloc_page(gfp_flags);
 151 }
 152
 153 static void ttm_tt_free_user_pages(struct ttm_tt *ttm)
 154 {
 155         int write;
 156         int dirty;
 157         struct page *page;
 158         int i;
 159         struct ttm_backend *be = ttm->be;
 160
 161         BUG_ON(!(ttm->page_flags & TTM_PAGE_FLAG_USER));
 162         write = ((ttm->page_flags & TTM_PAGE_FLAG_WRITE) != 0);
 163         dirty = ((ttm->page_flags & TTM_PAGE_FLAG_USER_DIRTY) != 0);
 164
 165         if (be)
 166                 be->func->clear(be);
 167
 168         for (i = 0; i < ttm->num_pages; ++i) {
 169                 page = ttm->pages[i];
 170                 if (page == NULL)
 171                         continue;
 172
 173                 if (page == ttm->dummy_read_page) {
 174                         BUG_ON(write);
 175                         continue;
 176                 }
 177
 178                 if (write && dirty && !PageReserved(page))
 179                         set_page_dirty_lock(page);
 180
 181                 ttm->pages[i] = NULL;
 182                 ttm_mem_global_free(ttm->bdev->mem_glob, PAGE_SIZE, false);
 183                 put_page(page);
 184         }
 185         ttm->state = tt_unpopulated;
 186         ttm->first_himem_page = ttm->num_pages;
 187         ttm->last_lomem_page = -1;
 188 }
 189
 190 static struct page *__ttm_tt_get_page(struct ttm_tt *ttm, int index)
 191 {
 192         struct page *p;
 193         struct ttm_bo_device *bdev = ttm->bdev;
 194         struct ttm_mem_global *mem_glob = bdev->mem_glob;
 195         int ret;
 196
 197         while (NULL == (p = ttm->pages[index])) {
 198                 p = ttm_tt_alloc_page(ttm->page_flags);
 199
 200                 if (!p)
 201                         return NULL;
 202
 203                 if (PageHighMem(p)) {
 204                         ret =
 205                             ttm_mem_global_alloc(mem_glob, PAGE_SIZE,
 206                                                  false, false, true);
 207                         if (unlikely(ret != 0))
 208                                 goto out_err;
 209                         ttm->pages[--ttm->first_himem_page] = p;
 210                 } else {
 211                         ret =
 212                             ttm_mem_global_alloc(mem_glob, PAGE_SIZE,
 213                                                  false, false, false);
 214                         if (unlikely(ret != 0))
 215                                 goto out_err;
 216                         ttm->pages[++ttm->last_lomem_page] = p;
 217                 }
 218         }
 219         return p;
 220 out_err:
 221         put_page(p);
 222         return NULL;
 223 }
 224
 225 struct page *ttm_tt_get_page(struct ttm_tt *ttm, int index)
 226 {
 227         int ret;
 228
 229         if (unlikely(ttm->page_flags & TTM_PAGE_FLAG_SWAPPED)) {
 230                 ret = ttm_tt_swapin(ttm);
 231                 if (unlikely(ret != 0))
 232                         return NULL;
 233         }
 234         return __ttm_tt_get_page(ttm, index);
 235 }
 236
 237 int ttm_tt_populate(struct ttm_tt *ttm)
 238 {
 239         struct page *page;
 240         unsigned long i;
 241         struct ttm_backend *be;
 242         int ret;
 243
 244         if (ttm->state != tt_unpopulated)
 245                 return 0;
 246
 247         if (unlikely(ttm->page_flags & TTM_PAGE_FLAG_SWAPPED)) {
 248                 ret = ttm_tt_swapin(ttm);
 249                 if (unlikely(ret != 0))
 250                         return ret;
 251         }
 252
 253         be = ttm->be;
 254
 255         for (i = 0; i < ttm->num_pages; ++i) {
 256                 page = __ttm_tt_get_page(ttm, i);
 257                 if (!page)
 258                         return -ENOMEM;
 259         }
 260
 261         be->func->populate(be, ttm->num_pages, ttm->pages,
 262                            ttm->dummy_read_page);
 263         ttm->state = tt_unbound;
 264         return 0;
 265 }
 266
 267 #ifdef CONFIG_X86
 268 static inline int ttm_tt_set_page_caching(struct page *p,
 269                                           enum ttm_caching_state c_state)
 270 {
 271         if (PageHighMem(p))
 272                 return 0;
 273
 274         switch (c_state) {
 275         case tt_cached:
 276                 return set_pages_wb(p, 1);
 277         case tt_wc:
 278             return set_memory_wc((unsigned long) page_address(p), 1);
 279         default:
 280                 return set_pages_uc(p, 1);
 281         }
 282 }
 283 #else /* CONFIG_X86 */
 284 static inline int ttm_tt_set_page_caching(struct page *p,
 285                                           enum ttm_caching_state c_state)
 286 {
 287         return 0;
 288 }
 289 #endif /* CONFIG_X86 */
 290
 291 /*
 292  * Change caching policy for the linear kernel map
 293  * for range of pages in a ttm.
 294  */
 295
 296 static int ttm_tt_set_caching(struct ttm_tt *ttm,
 297                               enum ttm_caching_state c_state)
 298 {
 299         int i, j;
 300         struct page *cur_page;
 301         int ret;
 302
 303         if (ttm->caching_state == c_state)
 304                 return 0;
 305
 306         if (c_state != tt_cached) {
 307                 ret = ttm_tt_populate(ttm);
 308                 if (unlikely(ret != 0))
 309                         return ret;
 310         }
 311
 312         if (ttm->caching_state == tt_cached)
 313                 ttm_tt_cache_flush(ttm->pages, ttm->num_pages);
 314
 315         for (i = 0; i < ttm->num_pages; ++i) {
 316                 cur_page = ttm->pages[i];
 317                 if (likely(cur_page != NULL)) {
 318                         ret = ttm_tt_set_page_caching(cur_page, c_state);
 319                         if (unlikely(ret != 0))
 320                                 goto out_err;
 321                 }
 322         }
 323
 324         ttm->caching_state = c_state;
 325
 326         return 0;
 327
 328 out_err:
 329         for (j = 0; j < i; ++j) {
 330                 cur_page = ttm->pages[j];
 331                 if (likely(cur_page != NULL)) {
 332                         (void)ttm_tt_set_page_caching(cur_page,
 333                                                       ttm->caching_state);
 334                 }
 335         }
 336
 337         return ret;
 338 }
 339
 340 int ttm_tt_set_placement_caching(struct ttm_tt *ttm, uint32_t placement)
 341 {
 342         enum ttm_caching_state state;
 343
 344         if (placement & TTM_PL_FLAG_WC)
 345                 state = tt_wc;
 346         else if (placement & TTM_PL_FLAG_UNCACHED)
 347                 state = tt_uncached;
 348         else
 349                 state = tt_cached;
 350
 351         return ttm_tt_set_caching(ttm, state);
 352 }
 353
 354 static void ttm_tt_free_alloced_pages(struct ttm_tt *ttm)
 355 {
 356         int i;
 357         struct page *cur_page;
 358         struct ttm_backend *be = ttm->be;
 359
 360         if (be)
 361                 be->func->clear(be);
 362         (void)ttm_tt_set_caching(ttm, tt_cached);
 363         for (i = 0; i < ttm->num_pages; ++i) {
 364                 cur_page = ttm->pages[i];
 365                 ttm->pages[i] = NULL;
 366                 if (cur_page) {
 367                         if (page_count(cur_page) != 1)
 368                                 printk(KERN_ERR TTM_PFX
 369                                        "Erroneous page count. "
 370                                        "Leaking pages.\n");
 371                         ttm_mem_global_free(ttm->bdev->mem_glob, PAGE_SIZE,
 372                                             PageHighMem(cur_page));
 373                         __free_page(cur_page);
 374                 }
 375         }
 376         ttm->state = tt_unpopulated;
 377         ttm->first_himem_page = ttm->num_pages;
 378         ttm->last_lomem_page = -1;
 379 }
 380
 381 void ttm_tt_destroy(struct ttm_tt *ttm)
 382 {
 383         struct ttm_backend *be;
 384
 385         if (unlikely(ttm == NULL))
 386                 return;
 387
 388         be = ttm->be;
 389         if (likely(be != NULL)) {
 390                 be->func->destroy(be);
 391                 ttm->be = NULL;
 392         }
 393
 394         if (likely(ttm->pages != NULL)) {
 395                 if (ttm->page_flags & TTM_PAGE_FLAG_USER)
 396                         ttm_tt_free_user_pages(ttm);
 397                 else
 398                         ttm_tt_free_alloced_pages(ttm);
 399
 400                 ttm_tt_free_page_directory(ttm);
 401         }
 402
 403         if (!(ttm->page_flags & TTM_PAGE_FLAG_PERSISTANT_SWAP) &&
 404             ttm->swap_storage)
 405                 fput(ttm->swap_storage);
 406
 407         kfree(ttm);
 408 }
 409
 410 int ttm_tt_set_user(struct ttm_tt *ttm,
 411                     struct task_struct *tsk,
 412                     unsigned long start, unsigned long num_pages)
 413 {
 414         struct mm_struct *mm = tsk->mm;
 415         int ret;
 416         int write = (ttm->page_flags & TTM_PAGE_FLAG_WRITE) != 0;
 417         struct ttm_mem_global *mem_glob = ttm->bdev->mem_glob;
 418
 419         BUG_ON(num_pages != ttm->num_pages);
 420         BUG_ON((ttm->page_flags & TTM_PAGE_FLAG_USER) == 0);
 421
 422         /**
 423          * Account user pages as lowmem pages for now.
 424          */
 425
 426         ret = ttm_mem_global_alloc(mem_glob, num_pages * PAGE_SIZE,
 427                                    false, false, false);
 428         if (unlikely(ret != 0))
 429                 return ret;
 430
 431         down_read(&mm->mmap_sem);
 432         ret = get_user_pages(tsk, mm, start, num_pages,
 433                              write, 0, ttm->pages, NULL);
 434         up_read(&mm->mmap_sem);
 435
 436         if (ret != num_pages && write) {
 437                 ttm_tt_free_user_pages(ttm);
 438                 ttm_mem_global_free(mem_glob, num_pages * PAGE_SIZE, false);
 439                 return -ENOMEM;
 440         }
 441
 442         ttm->tsk = tsk;
 443         ttm->start = start;
 444         ttm->state = tt_unbound;
 445
 446         return 0;
 447 }
 448
 449 struct ttm_tt *ttm_tt_create(struct ttm_bo_device *bdev, unsigned long size,
 450                              uint32_t page_flags, struct page *dummy_read_page)
 451 {
 452         struct ttm_bo_driver *bo_driver = bdev->driver;
 453         struct ttm_tt *ttm;
 454
 455         if (!bo_driver)
 456                 return NULL;
 457
 458         ttm = kzalloc(sizeof(*ttm), GFP_KERNEL);
 459         if (!ttm)
 460                 return NULL;
 461
 462         ttm->bdev = bdev;
 463
 464         ttm->num_pages = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
 465         ttm->first_himem_page = ttm->num_pages;
 466         ttm->last_lomem_page = -1;
 467         ttm->caching_state = tt_cached;
 468         ttm->page_flags = page_flags;
 469
 470         ttm->dummy_read_page = dummy_read_page;
 471
 472         ttm_tt_alloc_page_directory(ttm);
 473         if (!ttm->pages) {
 474                 ttm_tt_destroy(ttm);
 475                 printk(KERN_ERR TTM_PFX "Failed allocating page table\n");
 476                 return NULL;
 477         }
 478         ttm->be = bo_driver->create_ttm_backend_entry(bdev);
 479         if (!ttm->be) {
 480                 ttm_tt_destroy(ttm);
 481                 printk(KERN_ERR TTM_PFX "Failed creating ttm backend entry\n");
 482                 return NULL;
 483         }
 484         ttm->state = tt_unpopulated;
 485         return ttm;
 486 }
 487
 488 void ttm_tt_unbind(struct ttm_tt *ttm)
 489 {
 490         int ret;
 491         struct ttm_backend *be = ttm->be;
 492
 493         if (ttm->state == tt_bound) {
 494                 ret = be->func->unbind(be);
 495                 BUG_ON(ret);
 496                 ttm->state = tt_unbound;
 497         }
 498 }
 499
 500 int ttm_tt_bind(struct ttm_tt *ttm, struct ttm_mem_reg *bo_mem)
 501 {
 502         int ret = 0;
 503         struct ttm_backend *be;
 504
 505         if (!ttm)
 506                 return -EINVAL;
 507
 508         if (ttm->state == tt_bound)
 509                 return 0;
 510
 511         be = ttm->be;
 512
 513         ret = ttm_tt_populate(ttm);
 514         if (ret)
 515                 return ret;
 516
 517         ret = be->func->bind(be, bo_mem);
 518         if (ret) {
 519                 printk(KERN_ERR TTM_PFX "Couldn't bind backend.\n");
 520                 return ret;
 521         }
 522
 523         ttm->state = tt_bound;
 524
 525         if (ttm->page_flags & TTM_PAGE_FLAG_USER)
 526                 ttm->page_flags |= TTM_PAGE_FLAG_USER_DIRTY;
 527         return 0;
 528 }
 529 EXPORT_SYMBOL(ttm_tt_bind);
 530
 531 static int ttm_tt_swapin(struct ttm_tt *ttm)
 532 {
 533         struct address_space *swap_space;
 534         struct file *swap_storage;
 535         struct page *from_page;
 536         struct page *to_page;
 537         void *from_virtual;
 538         void *to_virtual;
 539         int i;
 540         int ret;
 541
 542         if (ttm->page_flags & TTM_PAGE_FLAG_USER) {
 543                 ret = ttm_tt_set_user(ttm, ttm->tsk, ttm->start,
 544                                       ttm->num_pages);
 545                 if (unlikely(ret != 0))
 546                         return ret;
 547
 548                 ttm->page_flags &= ~TTM_PAGE_FLAG_SWAPPED;
 549                 return 0;
 550         }
 551
 552         swap_storage = ttm->swap_storage;
 553         BUG_ON(swap_storage == NULL);
 554
 555         swap_space = swap_storage->f_path.dentry->d_inode->i_mapping;
 556
 557         for (i = 0; i < ttm->num_pages; ++i) {
 558                 from_page = read_mapping_page(swap_space, i, NULL);
 559                 if (IS_ERR(from_page))
 560                         goto out_err;
 561                 to_page = __ttm_tt_get_page(ttm, i);
 562                 if (unlikely(to_page == NULL))
 563                         goto out_err;
 564
 565                 preempt_disable();
 566                 from_virtual = kmap_atomic(from_page, KM_USER0);
 567                 to_virtual = kmap_atomic(to_page, KM_USER1);
 568                 memcpy(to_virtual, from_virtual, PAGE_SIZE);
 569                 kunmap_atomic(to_virtual, KM_USER1);
 570                 kunmap_atomic(from_virtual, KM_USER0);
 571                 preempt_enable();
 572                 page_cache_release(from_page);
 573         }
 574
 575         if (!(ttm->page_flags & TTM_PAGE_FLAG_PERSISTANT_SWAP))
 576                 fput(swap_storage);
 577         ttm->swap_storage = NULL;
 578         ttm->page_flags &= ~TTM_PAGE_FLAG_SWAPPED;
 579
 580         return 0;
 581 out_err:
 582         ttm_tt_free_alloced_pages(ttm);
 583         return -ENOMEM;
 584 }
 585
 586 int ttm_tt_swapout(struct ttm_tt *ttm, struct file *persistant_swap_storage)
 587 {
 588         struct address_space *swap_space;
 589         struct file *swap_storage;
 590         struct page *from_page;
 591         struct page *to_page;
 592         void *from_virtual;
 593         void *to_virtual;
 594         int i;
 595
 596         BUG_ON(ttm->state != tt_unbound && ttm->state != tt_unpopulated);
 597         BUG_ON(ttm->caching_state != tt_cached);
 598
 599         /*
 600          * For user buffers, just unpin the pages, as there should be
 601          * vma references.
 602          */
 603
 604         if (ttm->page_flags & TTM_PAGE_FLAG_USER) {
 605                 ttm_tt_free_user_pages(ttm);
 606                 ttm->page_flags |= TTM_PAGE_FLAG_SWAPPED;
 607                 ttm->swap_storage = NULL;
 608                 return 0;
 609         }
 610
 611         if (!persistant_swap_storage) {
 612                 swap_storage = shmem_file_setup("ttm swap",
 613                                                 ttm->num_pages << PAGE_SHIFT,
 614                                                 0);
 615                 if (unlikely(IS_ERR(swap_storage))) {
 616                         printk(KERN_ERR "Failed allocating swap storage.\n");
 617                         return -ENOMEM;
 618                 }
 619         } else
 620                 swap_storage = persistant_swap_storage;
 621
 622         swap_space = swap_storage->f_path.dentry->d_inode->i_mapping;
 623
 624         for (i = 0; i < ttm->num_pages; ++i) {
 625                 from_page = ttm->pages[i];
 626                 if (unlikely(from_page == NULL))
 627                         continue;
 628                 to_page = read_mapping_page(swap_space, i, NULL);
 629                 if (unlikely(to_page == NULL))
 630                         goto out_err;
 631
 632                 preempt_disable();
 633                 from_virtual = kmap_atomic(from_page, KM_USER0);
 634                 to_virtual = kmap_atomic(to_page, KM_USER1);
 635                 memcpy(to_virtual, from_virtual, PAGE_SIZE);
 636                 kunmap_atomic(to_virtual, KM_USER1);
 637                 kunmap_atomic(from_virtual, KM_USER0);
 638                 preempt_enable();
 639                 set_page_dirty(to_page);
 640                 mark_page_accessed(to_page);
 641                 page_cache_release(to_page);
 642         }
 643
 644         ttm_tt_free_alloced_pages(ttm);
 645         ttm->swap_storage = swap_storage;
 646         ttm->page_flags |= TTM_PAGE_FLAG_SWAPPED;
 647         if (persistant_swap_storage)
 648                 ttm->page_flags |= TTM_PAGE_FLAG_PERSISTANT_SWAP;
 649
 650         return 0;
 651 out_err:
 652         if (!persistant_swap_storage)
 653                 fput(swap_storage);
 654
 655         return -ENOMEM;
 656 }