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