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