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