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/file.h>
  35 #include <linux/swap.h>
  36 #include "drm_cache.h"
  37 #include "drm_mem_util.h"
  38 #include "ttm/ttm_module.h"
  39 #include "ttm/ttm_bo_driver.h"
  40 #include "ttm/ttm_placement.h"
  41
  42 static int ttm_tt_swapin(struct ttm_tt *ttm);
  43
  44 /**
  45  * Allocates storage for pointers to the pages that back the ttm.
  46  */
  47 static void ttm_tt_alloc_page_directory(struct ttm_tt *ttm)
  48 {
  49         ttm->pages = drm_calloc_large(ttm->num_pages, sizeof(*ttm->pages));
  50 }
  51
  52 static void ttm_tt_free_page_directory(struct ttm_tt *ttm)
  53 {
  54         drm_free_large(ttm->pages);
  55         ttm->pages = NULL;
  56 }
  57
  58 static struct page *ttm_tt_alloc_page(unsigned page_flags)
  59 {
  60         gfp_t gfp_flags = GFP_USER;
  61
  62         if (page_flags & TTM_PAGE_FLAG_ZERO_ALLOC)
  63                 gfp_flags |= __GFP_ZERO;
  64
  65         if (page_flags & TTM_PAGE_FLAG_DMA32)
  66                 gfp_flags |= __GFP_DMA32;
  67         else
  68                 gfp_flags |= __GFP_HIGHMEM;
  69
  70         return alloc_page(gfp_flags);
  71 }
  72
  73 static void ttm_tt_free_user_pages(struct ttm_tt *ttm)
  74 {
  75         int write;
  76         int dirty;
  77         struct page *page;
  78         int i;
  79         struct ttm_backend *be = ttm->be;
  80
  81         BUG_ON(!(ttm->page_flags & TTM_PAGE_FLAG_USER));
  82         write = ((ttm->page_flags & TTM_PAGE_FLAG_WRITE) != 0);
  83         dirty = ((ttm->page_flags & TTM_PAGE_FLAG_USER_DIRTY) != 0);
  84
  85         if (be)
  86                 be->func->clear(be);
  87
  88         for (i = 0; i < ttm->num_pages; ++i) {
  89                 page = ttm->pages[i];
  90                 if (page == NULL)
  91                         continue;
  92
  93                 if (page == ttm->dummy_read_page) {
  94                         BUG_ON(write);
  95                         continue;
  96                 }
  97
  98                 if (write && dirty && !PageReserved(page))
  99                         set_page_dirty_lock(page);
 100
 101                 ttm->pages[i] = NULL;
 102                 ttm_mem_global_free(ttm->glob->mem_glob, PAGE_SIZE);
 103                 put_page(page);
 104         }
 105         ttm->state = tt_unpopulated;
 106         ttm->first_himem_page = ttm->num_pages;
 107         ttm->last_lomem_page = -1;
 108 }
 109
 110 static struct page *__ttm_tt_get_page(struct ttm_tt *ttm, int index)
 111 {
 112         struct page *p;
 113         struct ttm_mem_global *mem_glob = ttm->glob->mem_glob;
 114         int ret;
 115
 116         while (NULL == (p = ttm->pages[index])) {
 117                 p = ttm_tt_alloc_page(ttm->page_flags);
 118
 119                 if (!p)
 120                         return NULL;
 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);
 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 (c_state != tt_cached) {
 231                 ret = ttm_tt_populate(ttm);
 232                 if (unlikely(ret != 0))
 233                         return ret;
 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         struct page *cur_page;
 285         struct ttm_backend *be = ttm->be;
 286
 287         if (be)
 288                 be->func->clear(be);
 289         (void)ttm_tt_set_caching(ttm, tt_cached);
 290         for (i = 0; i < ttm->num_pages; ++i) {
 291                 cur_page = ttm->pages[i];
 292                 ttm->pages[i] = NULL;
 293                 if (cur_page) {
 294                         if (page_count(cur_page) != 1)
 295                                 printk(KERN_ERR TTM_PFX
 296                                        "Erroneous page count. "
 297                                        "Leaking pages.\n");
 298                         ttm_mem_global_free_page(ttm->glob->mem_glob,
 299                                                  cur_page);
 300                         __free_page(cur_page);
 301                 }
 302         }
 303         ttm->state = tt_unpopulated;
 304         ttm->first_himem_page = ttm->num_pages;
 305         ttm->last_lomem_page = -1;
 306 }
 307
 308 void ttm_tt_destroy(struct ttm_tt *ttm)
 309 {
 310         struct ttm_backend *be;
 311
 312         if (unlikely(ttm == NULL))
 313                 return;
 314
 315         be = ttm->be;
 316         if (likely(be != NULL)) {
 317                 be->func->destroy(be);
 318                 ttm->be = NULL;
 319         }
 320
 321         if (likely(ttm->pages != NULL)) {
 322                 if (ttm->page_flags & TTM_PAGE_FLAG_USER)
 323                         ttm_tt_free_user_pages(ttm);
 324                 else
 325                         ttm_tt_free_alloced_pages(ttm);
 326
 327                 ttm_tt_free_page_directory(ttm);
 328         }
 329
 330         if (!(ttm->page_flags & TTM_PAGE_FLAG_PERSISTANT_SWAP) &&
 331             ttm->swap_storage)
 332                 fput(ttm->swap_storage);
 333
 334         kfree(ttm);
 335 }
 336
 337 int ttm_tt_set_user(struct ttm_tt *ttm,
 338                     struct task_struct *tsk,
 339                     unsigned long start, unsigned long num_pages)
 340 {
 341         struct mm_struct *mm = tsk->mm;
 342         int ret;
 343         int write = (ttm->page_flags & TTM_PAGE_FLAG_WRITE) != 0;
 344         struct ttm_mem_global *mem_glob = ttm->glob->mem_glob;
 345
 346         BUG_ON(num_pages != ttm->num_pages);
 347         BUG_ON((ttm->page_flags & TTM_PAGE_FLAG_USER) == 0);
 348
 349         /**
 350          * Account user pages as lowmem pages for now.
 351          */
 352
 353         ret = ttm_mem_global_alloc(mem_glob, num_pages * PAGE_SIZE,
 354                                    false, false);
 355         if (unlikely(ret != 0))
 356                 return ret;
 357
 358         down_read(&mm->mmap_sem);
 359         ret = get_user_pages(tsk, mm, start, num_pages,
 360                              write, 0, ttm->pages, NULL);
 361         up_read(&mm->mmap_sem);
 362
 363         if (ret != num_pages && write) {
 364                 ttm_tt_free_user_pages(ttm);
 365                 ttm_mem_global_free(mem_glob, num_pages * PAGE_SIZE);
 366                 return -ENOMEM;
 367         }
 368
 369         ttm->tsk = tsk;
 370         ttm->start = start;
 371         ttm->state = tt_unbound;
 372
 373         return 0;
 374 }
 375
 376 struct ttm_tt *ttm_tt_create(struct ttm_bo_device *bdev, unsigned long size,
 377                              uint32_t page_flags, struct page *dummy_read_page)
 378 {
 379         struct ttm_bo_driver *bo_driver = bdev->driver;
 380         struct ttm_tt *ttm;
 381
 382         if (!bo_driver)
 383                 return NULL;
 384
 385         ttm = kzalloc(sizeof(*ttm), GFP_KERNEL);
 386         if (!ttm)
 387                 return NULL;
 388
 389         ttm->glob = bdev->glob;
 390         ttm->num_pages = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
 391         ttm->first_himem_page = ttm->num_pages;
 392         ttm->last_lomem_page = -1;
 393         ttm->caching_state = tt_cached;
 394         ttm->page_flags = page_flags;
 395
 396         ttm->dummy_read_page = dummy_read_page;
 397
 398         ttm_tt_alloc_page_directory(ttm);
 399         if (!ttm->pages) {
 400                 ttm_tt_destroy(ttm);
 401                 printk(KERN_ERR TTM_PFX "Failed allocating page table\n");
 402                 return NULL;
 403         }
 404         ttm->be = bo_driver->create_ttm_backend_entry(bdev);
 405         if (!ttm->be) {
 406                 ttm_tt_destroy(ttm);
 407                 printk(KERN_ERR TTM_PFX "Failed creating ttm backend entry\n");
 408                 return NULL;
 409         }
 410         ttm->state = tt_unpopulated;
 411         return ttm;
 412 }
 413
 414 void ttm_tt_unbind(struct ttm_tt *ttm)
 415 {
 416         int ret;
 417         struct ttm_backend *be = ttm->be;
 418
 419         if (ttm->state == tt_bound) {
 420                 ret = be->func->unbind(be);
 421                 BUG_ON(ret);
 422                 ttm->state = tt_unbound;
 423         }
 424 }
 425
 426 int ttm_tt_bind(struct ttm_tt *ttm, struct ttm_mem_reg *bo_mem)
 427 {
 428         int ret = 0;
 429         struct ttm_backend *be;
 430
 431         if (!ttm)
 432                 return -EINVAL;
 433
 434         if (ttm->state == tt_bound)
 435                 return 0;
 436
 437         be = ttm->be;
 438
 439         ret = ttm_tt_populate(ttm);
 440         if (ret)
 441                 return ret;
 442
 443         ret = be->func->bind(be, bo_mem);
 444         if (ret) {
 445                 printk(KERN_ERR TTM_PFX "Couldn't bind backend.\n");
 446                 return ret;
 447         }
 448
 449         ttm->state = tt_bound;
 450
 451         if (ttm->page_flags & TTM_PAGE_FLAG_USER)
 452                 ttm->page_flags |= TTM_PAGE_FLAG_USER_DIRTY;
 453         return 0;
 454 }
 455 EXPORT_SYMBOL(ttm_tt_bind);
 456
 457 static int ttm_tt_swapin(struct ttm_tt *ttm)
 458 {
 459         struct address_space *swap_space;
 460         struct file *swap_storage;
 461         struct page *from_page;
 462         struct page *to_page;
 463         void *from_virtual;
 464         void *to_virtual;
 465         int i;
 466         int ret = -ENOMEM;
 467
 468         if (ttm->page_flags & TTM_PAGE_FLAG_USER) {
 469                 ret = ttm_tt_set_user(ttm, ttm->tsk, ttm->start,
 470                                       ttm->num_pages);
 471                 if (unlikely(ret != 0))
 472                         return ret;
 473
 474                 ttm->page_flags &= ~TTM_PAGE_FLAG_SWAPPED;
 475                 return 0;
 476         }
 477
 478         swap_storage = ttm->swap_storage;
 479         BUG_ON(swap_storage == NULL);
 480
 481         swap_space = swap_storage->f_path.dentry->d_inode->i_mapping;
 482
 483         for (i = 0; i < ttm->num_pages; ++i) {
 484                 from_page = read_mapping_page(swap_space, i, NULL);
 485                 if (IS_ERR(from_page)) {
 486                         ret = PTR_ERR(from_page);
 487                         goto out_err;
 488                 }
 489                 to_page = __ttm_tt_get_page(ttm, i);
 490                 if (unlikely(to_page == NULL))
 491                         goto out_err;
 492
 493                 preempt_disable();
 494                 from_virtual = kmap_atomic(from_page, KM_USER0);
 495                 to_virtual = kmap_atomic(to_page, KM_USER1);
 496                 memcpy(to_virtual, from_virtual, PAGE_SIZE);
 497                 kunmap_atomic(to_virtual, KM_USER1);
 498                 kunmap_atomic(from_virtual, KM_USER0);
 499                 preempt_enable();
 500                 page_cache_release(from_page);
 501         }
 502
 503         if (!(ttm->page_flags & TTM_PAGE_FLAG_PERSISTANT_SWAP))
 504                 fput(swap_storage);
 505         ttm->swap_storage = NULL;
 506         ttm->page_flags &= ~TTM_PAGE_FLAG_SWAPPED;
 507
 508         return 0;
 509 out_err:
 510         ttm_tt_free_alloced_pages(ttm);
 511         return ret;
 512 }
 513
 514 int ttm_tt_swapout(struct ttm_tt *ttm, struct file *persistant_swap_storage)
 515 {
 516         struct address_space *swap_space;
 517         struct file *swap_storage;
 518         struct page *from_page;
 519         struct page *to_page;
 520         void *from_virtual;
 521         void *to_virtual;
 522         int i;
 523         int ret = -ENOMEM;
 524
 525         BUG_ON(ttm->state != tt_unbound && ttm->state != tt_unpopulated);
 526         BUG_ON(ttm->caching_state != tt_cached);
 527
 528         /*
 529          * For user buffers, just unpin the pages, as there should be
 530          * vma references.
 531          */
 532
 533         if (ttm->page_flags & TTM_PAGE_FLAG_USER) {
 534                 ttm_tt_free_user_pages(ttm);
 535                 ttm->page_flags |= TTM_PAGE_FLAG_SWAPPED;
 536                 ttm->swap_storage = NULL;
 537                 return 0;
 538         }
 539
 540         if (!persistant_swap_storage) {
 541                 swap_storage = shmem_file_setup("ttm swap",
 542                                                 ttm->num_pages << PAGE_SHIFT,
 543                                                 0);
 544                 if (unlikely(IS_ERR(swap_storage))) {
 545                         printk(KERN_ERR "Failed allocating swap storage.\n");
 546                         return PTR_ERR(swap_storage);
 547                 }
 548         } else
 549                 swap_storage = persistant_swap_storage;
 550
 551         swap_space = swap_storage->f_path.dentry->d_inode->i_mapping;
 552
 553         for (i = 0; i < ttm->num_pages; ++i) {
 554                 from_page = ttm->pages[i];
 555                 if (unlikely(from_page == NULL))
 556                         continue;
 557                 to_page = read_mapping_page(swap_space, i, NULL);
 558                 if (unlikely(IS_ERR(to_page))) {
 559                         ret = PTR_ERR(to_page);
 560                         goto out_err;
 561                 }
 562                 preempt_disable();
 563                 from_virtual = kmap_atomic(from_page, KM_USER0);
 564                 to_virtual = kmap_atomic(to_page, KM_USER1);
 565                 memcpy(to_virtual, from_virtual, PAGE_SIZE);
 566                 kunmap_atomic(to_virtual, KM_USER1);
 567                 kunmap_atomic(from_virtual, KM_USER0);
 568                 preempt_enable();
 569                 set_page_dirty(to_page);
 570                 mark_page_accessed(to_page);
 571                 page_cache_release(to_page);
 572         }
 573
 574         ttm_tt_free_alloced_pages(ttm);
 575         ttm->swap_storage = swap_storage;
 576         ttm->page_flags |= TTM_PAGE_FLAG_SWAPPED;
 577         if (persistant_swap_storage)
 578                 ttm->page_flags |= TTM_PAGE_FLAG_PERSISTANT_SWAP;
 579
 580         return 0;
 581 out_err:
 582         if (!persistant_swap_storage)
 583                 fput(swap_storage);
 584
 585         return ret;
 586 }