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
  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 struct page *ttm_tt_alloc_page(unsigned page_flags)
  60 {
  61         gfp_t gfp_flags = GFP_USER;
  62
  63         if (page_flags & TTM_PAGE_FLAG_ZERO_ALLOC)
  64                 gfp_flags |= __GFP_ZERO;
  65
  66         if (page_flags & TTM_PAGE_FLAG_DMA32)
  67                 gfp_flags |= __GFP_DMA32;
  68         else
  69                 gfp_flags |= __GFP_HIGHMEM;
  70
  71         return alloc_page(gfp_flags);
  72 }
  73
  74 static void ttm_tt_free_user_pages(struct ttm_tt *ttm)
  75 {
  76         int write;
  77         int dirty;
  78         struct page *page;
  79         int i;
  80         struct ttm_backend *be = ttm->be;
  81
  82         BUG_ON(!(ttm->page_flags & TTM_PAGE_FLAG_USER));
  83         write = ((ttm->page_flags & TTM_PAGE_FLAG_WRITE) != 0);
  84         dirty = ((ttm->page_flags & TTM_PAGE_FLAG_USER_DIRTY) != 0);
  85
  86         if (be)
  87                 be->func->clear(be);
  88
  89         for (i = 0; i < ttm->num_pages; ++i) {
  90                 page = ttm->pages[i];
  91                 if (page == NULL)
  92                         continue;
  93
  94                 if (page == ttm->dummy_read_page) {
  95                         BUG_ON(write);
  96                         continue;
  97                 }
  98
  99                 if (write && dirty && !PageReserved(page))
 100                         set_page_dirty_lock(page);
 101
 102                 ttm->pages[i] = NULL;
 103                 ttm_mem_global_free(ttm->glob->mem_glob, PAGE_SIZE);
 104                 put_page(page);
 105         }
 106         ttm->state = tt_unpopulated;
 107         ttm->first_himem_page = ttm->num_pages;
 108         ttm->last_lomem_page = -1;
 109 }
 110
 111 static struct page *__ttm_tt_get_page(struct ttm_tt *ttm, int index)
 112 {
 113         struct page *p;
 114         struct ttm_mem_global *mem_glob = ttm->glob->mem_glob;
 115         int ret;
 116
 117         while (NULL == (p = ttm->pages[index])) {
 118                 p = ttm_tt_alloc_page(ttm->page_flags);
 119
 120                 if (!p)
 121                         return NULL;
 122
 123                 ret = ttm_mem_global_alloc_page(mem_glob, p, false, false);
 124                 if (unlikely(ret != 0))
 125                         goto out_err;
 126
 127                 if (PageHighMem(p))
 128                         ttm->pages[--ttm->first_himem_page] = p;
 129                 else
 130                         ttm->pages[++ttm->last_lomem_page] = p;
 131         }
 132         return p;
 133 out_err:
 134         put_page(p);
 135         return NULL;
 136 }
 137
 138 struct page *ttm_tt_get_page(struct ttm_tt *ttm, int index)
 139 {
 140         int ret;
 141
 142         if (unlikely(ttm->page_flags & TTM_PAGE_FLAG_SWAPPED)) {
 143                 ret = ttm_tt_swapin(ttm);
 144                 if (unlikely(ret != 0))
 145                         return NULL;
 146         }
 147         return __ttm_tt_get_page(ttm, index);
 148 }
 149
 150 int ttm_tt_populate(struct ttm_tt *ttm)
 151 {
 152         struct page *page;
 153         unsigned long i;
 154         struct ttm_backend *be;
 155         int ret;
 156
 157         if (ttm->state != tt_unpopulated)
 158                 return 0;
 159
 160         if (unlikely(ttm->page_flags & TTM_PAGE_FLAG_SWAPPED)) {
 161                 ret = ttm_tt_swapin(ttm);
 162                 if (unlikely(ret != 0))
 163                         return ret;
 164         }
 165
 166         be = ttm->be;
 167
 168         for (i = 0; i < ttm->num_pages; ++i) {
 169                 page = __ttm_tt_get_page(ttm, i);
 170                 if (!page)
 171                         return -ENOMEM;
 172         }
 173
 174         be->func->populate(be, ttm->num_pages, ttm->pages,
 175                            ttm->dummy_read_page);
 176         ttm->state = tt_unbound;
 177         return 0;
 178 }
 179 EXPORT_SYMBOL(ttm_tt_populate);
 180
 181 #ifdef CONFIG_X86
 182 static inline int ttm_tt_set_page_caching(struct page *p,
 183                                           enum ttm_caching_state c_old,
 184                                           enum ttm_caching_state c_new)
 185 {
 186         int ret = 0;
 187
 188         if (PageHighMem(p))
 189                 return 0;
 190
 191         if (c_old != tt_cached) {
 192                 /* p isn't in the default caching state, set it to
 193                  * writeback first to free its current memtype. */
 194
 195                 ret = set_pages_wb(p, 1);
 196                 if (ret)
 197                         return ret;
 198         }
 199
 200         if (c_new == tt_wc)
 201                 ret = set_memory_wc((unsigned long) page_address(p), 1);
 202         else if (c_new == tt_uncached)
 203                 ret = set_pages_uc(p, 1);
 204
 205         return ret;
 206 }
 207 #else /* CONFIG_X86 */
 208 static inline int ttm_tt_set_page_caching(struct page *p,
 209                                           enum ttm_caching_state c_old,
 210                                           enum ttm_caching_state c_new)
 211 {
 212         return 0;
 213 }
 214 #endif /* CONFIG_X86 */
 215
 216 /*
 217  * Change caching policy for the linear kernel map
 218  * for range of pages in a ttm.
 219  */
 220
 221 static int ttm_tt_set_caching(struct ttm_tt *ttm,
 222                               enum ttm_caching_state c_state)
 223 {
 224         int i, j;
 225         struct page *cur_page;
 226         int ret;
 227
 228         if (ttm->caching_state == c_state)
 229                 return 0;
 230
 231         if (c_state != tt_cached) {
 232                 ret = ttm_tt_populate(ttm);
 233                 if (unlikely(ret != 0))
 234                         return ret;
 235         }
 236
 237         if (ttm->caching_state == tt_cached)
 238                 drm_clflush_pages(ttm->pages, ttm->num_pages);
 239
 240         for (i = 0; i < ttm->num_pages; ++i) {
 241                 cur_page = ttm->pages[i];
 242                 if (likely(cur_page != NULL)) {
 243                         ret = ttm_tt_set_page_caching(cur_page,
 244                                                       ttm->caching_state,
 245                                                       c_state);
 246                         if (unlikely(ret != 0))
 247                                 goto out_err;
 248                 }
 249         }
 250
 251         ttm->caching_state = c_state;
 252
 253         return 0;
 254
 255 out_err:
 256         for (j = 0; j < i; ++j) {
 257                 cur_page = ttm->pages[j];
 258                 if (likely(cur_page != NULL)) {
 259                         (void)ttm_tt_set_page_caching(cur_page, c_state,
 260                                                       ttm->caching_state);
 261                 }
 262         }
 263
 264         return ret;
 265 }
 266
 267 int ttm_tt_set_placement_caching(struct ttm_tt *ttm, uint32_t placement)
 268 {
 269         enum ttm_caching_state state;
 270
 271         if (placement & TTM_PL_FLAG_WC)
 272                 state = tt_wc;
 273         else if (placement & TTM_PL_FLAG_UNCACHED)
 274                 state = tt_uncached;
 275         else
 276                 state = tt_cached;
 277
 278         return ttm_tt_set_caching(ttm, state);
 279 }
 280 EXPORT_SYMBOL(ttm_tt_set_placement_caching);
 281
 282 static void ttm_tt_free_alloced_pages(struct ttm_tt *ttm)
 283 {
 284         int i;
 285         struct page *cur_page;
 286         struct ttm_backend *be = ttm->be;
 287
 288         if (be)
 289                 be->func->clear(be);
 290         (void)ttm_tt_set_caching(ttm, tt_cached);
 291         for (i = 0; i < ttm->num_pages; ++i) {
 292                 cur_page = ttm->pages[i];
 293                 ttm->pages[i] = NULL;
 294                 if (cur_page) {
 295                         if (page_count(cur_page) != 1)
 296                                 printk(KERN_ERR TTM_PFX
 297                                        "Erroneous page count. "
 298                                        "Leaking pages.\n");
 299                         ttm_mem_global_free_page(ttm->glob->mem_glob,
 300                                                  cur_page);
 301                         __free_page(cur_page);
 302                 }
 303         }
 304         ttm->state = tt_unpopulated;
 305         ttm->first_himem_page = ttm->num_pages;
 306         ttm->last_lomem_page = -1;
 307 }
 308
 309 void ttm_tt_destroy(struct ttm_tt *ttm)
 310 {
 311         struct ttm_backend *be;
 312
 313         if (unlikely(ttm == NULL))
 314                 return;
 315
 316         be = ttm->be;
 317         if (likely(be != NULL)) {
 318                 be->func->destroy(be);
 319                 ttm->be = NULL;
 320         }
 321
 322         if (likely(ttm->pages != NULL)) {
 323                 if (ttm->page_flags & TTM_PAGE_FLAG_USER)
 324                         ttm_tt_free_user_pages(ttm);
 325                 else
 326                         ttm_tt_free_alloced_pages(ttm);
 327
 328                 ttm_tt_free_page_directory(ttm);
 329         }
 330
 331         if (!(ttm->page_flags & TTM_PAGE_FLAG_PERSISTANT_SWAP) &&
 332             ttm->swap_storage)
 333                 fput(ttm->swap_storage);
 334
 335         kfree(ttm);
 336 }
 337
 338 int ttm_tt_set_user(struct ttm_tt *ttm,
 339                     struct task_struct *tsk,
 340                     unsigned long start, unsigned long num_pages)
 341 {
 342         struct mm_struct *mm = tsk->mm;
 343         int ret;
 344         int write = (ttm->page_flags & TTM_PAGE_FLAG_WRITE) != 0;
 345         struct ttm_mem_global *mem_glob = ttm->glob->mem_glob;
 346
 347         BUG_ON(num_pages != ttm->num_pages);
 348         BUG_ON((ttm->page_flags & TTM_PAGE_FLAG_USER) == 0);
 349
 350         /**
 351          * Account user pages as lowmem pages for now.
 352          */
 353
 354         ret = ttm_mem_global_alloc(mem_glob, num_pages * PAGE_SIZE,
 355                                    false, false);
 356         if (unlikely(ret != 0))
 357                 return ret;
 358
 359         down_read(&mm->mmap_sem);
 360         ret = get_user_pages(tsk, mm, start, num_pages,
 361                              write, 0, ttm->pages, NULL);
 362         up_read(&mm->mmap_sem);
 363
 364         if (ret != num_pages && write) {
 365                 ttm_tt_free_user_pages(ttm);
 366                 ttm_mem_global_free(mem_glob, num_pages * PAGE_SIZE);
 367                 return -ENOMEM;
 368         }
 369
 370         ttm->tsk = tsk;
 371         ttm->start = start;
 372         ttm->state = tt_unbound;
 373
 374         return 0;
 375 }
 376
 377 struct ttm_tt *ttm_tt_create(struct ttm_bo_device *bdev, unsigned long size,
 378                              uint32_t page_flags, struct page *dummy_read_page)
 379 {
 380         struct ttm_bo_driver *bo_driver = bdev->driver;
 381         struct ttm_tt *ttm;
 382
 383         if (!bo_driver)
 384                 return NULL;
 385
 386         ttm = kzalloc(sizeof(*ttm), GFP_KERNEL);
 387         if (!ttm)
 388                 return NULL;
 389
 390         ttm->glob = bdev->glob;
 391         ttm->num_pages = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
 392         ttm->first_himem_page = ttm->num_pages;
 393         ttm->last_lomem_page = -1;
 394         ttm->caching_state = tt_cached;
 395         ttm->page_flags = page_flags;
 396
 397         ttm->dummy_read_page = dummy_read_page;
 398
 399         ttm_tt_alloc_page_directory(ttm);
 400         if (!ttm->pages) {
 401                 ttm_tt_destroy(ttm);
 402                 printk(KERN_ERR TTM_PFX "Failed allocating page table\n");
 403                 return NULL;
 404         }
 405         ttm->be = bo_driver->create_ttm_backend_entry(bdev);
 406         if (!ttm->be) {
 407                 ttm_tt_destroy(ttm);
 408                 printk(KERN_ERR TTM_PFX "Failed creating ttm backend entry\n");
 409                 return NULL;
 410         }
 411         ttm->state = tt_unpopulated;
 412         return ttm;
 413 }
 414
 415 void ttm_tt_unbind(struct ttm_tt *ttm)
 416 {
 417         int ret;
 418         struct ttm_backend *be = ttm->be;
 419
 420         if (ttm->state == tt_bound) {
 421                 ret = be->func->unbind(be);
 422                 BUG_ON(ret);
 423                 ttm->state = tt_unbound;
 424         }
 425 }
 426
 427 int ttm_tt_bind(struct ttm_tt *ttm, struct ttm_mem_reg *bo_mem)
 428 {
 429         int ret = 0;
 430         struct ttm_backend *be;
 431
 432         if (!ttm)
 433                 return -EINVAL;
 434
 435         if (ttm->state == tt_bound)
 436                 return 0;
 437
 438         be = ttm->be;
 439
 440         ret = ttm_tt_populate(ttm);
 441         if (ret)
 442                 return ret;
 443
 444         ret = be->func->bind(be, bo_mem);
 445         if (ret) {
 446                 printk(KERN_ERR TTM_PFX "Couldn't bind backend.\n");
 447                 return ret;
 448         }
 449
 450         ttm->state = tt_bound;
 451
 452         if (ttm->page_flags & TTM_PAGE_FLAG_USER)
 453                 ttm->page_flags |= TTM_PAGE_FLAG_USER_DIRTY;
 454         return 0;
 455 }
 456 EXPORT_SYMBOL(ttm_tt_bind);
 457
 458 static int ttm_tt_swapin(struct ttm_tt *ttm)
 459 {
 460         struct address_space *swap_space;
 461         struct file *swap_storage;
 462         struct page *from_page;
 463         struct page *to_page;
 464         void *from_virtual;
 465         void *to_virtual;
 466         int i;
 467         int ret = -ENOMEM;
 468
 469         if (ttm->page_flags & TTM_PAGE_FLAG_USER) {
 470                 ret = ttm_tt_set_user(ttm, ttm->tsk, ttm->start,
 471                                       ttm->num_pages);
 472                 if (unlikely(ret != 0))
 473                         return ret;
 474
 475                 ttm->page_flags &= ~TTM_PAGE_FLAG_SWAPPED;
 476                 return 0;
 477         }
 478
 479         swap_storage = ttm->swap_storage;
 480         BUG_ON(swap_storage == NULL);
 481
 482         swap_space = swap_storage->f_path.dentry->d_inode->i_mapping;
 483
 484         for (i = 0; i < ttm->num_pages; ++i) {
 485                 from_page = read_mapping_page(swap_space, i, NULL);
 486                 if (IS_ERR(from_page)) {
 487                         ret = PTR_ERR(from_page);
 488                         goto out_err;
 489                 }
 490                 to_page = __ttm_tt_get_page(ttm, i);
 491                 if (unlikely(to_page == NULL))
 492                         goto out_err;
 493
 494                 preempt_disable();
 495                 from_virtual = kmap_atomic(from_page, KM_USER0);
 496                 to_virtual = kmap_atomic(to_page, KM_USER1);
 497                 memcpy(to_virtual, from_virtual, PAGE_SIZE);
 498                 kunmap_atomic(to_virtual, KM_USER1);
 499                 kunmap_atomic(from_virtual, KM_USER0);
 500                 preempt_enable();
 501                 page_cache_release(from_page);
 502         }
 503
 504         if (!(ttm->page_flags & TTM_PAGE_FLAG_PERSISTANT_SWAP))
 505                 fput(swap_storage);
 506         ttm->swap_storage = NULL;
 507         ttm->page_flags &= ~TTM_PAGE_FLAG_SWAPPED;
 508
 509         return 0;
 510 out_err:
 511         ttm_tt_free_alloced_pages(ttm);
 512         return ret;
 513 }
 514
 515 int ttm_tt_swapout(struct ttm_tt *ttm, struct file *persistant_swap_storage)
 516 {
 517         struct address_space *swap_space;
 518         struct file *swap_storage;
 519         struct page *from_page;
 520         struct page *to_page;
 521         void *from_virtual;
 522         void *to_virtual;
 523         int i;
 524         int ret = -ENOMEM;
 525
 526         BUG_ON(ttm->state != tt_unbound && ttm->state != tt_unpopulated);
 527         BUG_ON(ttm->caching_state != tt_cached);
 528
 529         /*
 530          * For user buffers, just unpin the pages, as there should be
 531          * vma references.
 532          */
 533
 534         if (ttm->page_flags & TTM_PAGE_FLAG_USER) {
 535                 ttm_tt_free_user_pages(ttm);
 536                 ttm->page_flags |= TTM_PAGE_FLAG_SWAPPED;
 537                 ttm->swap_storage = NULL;
 538                 return 0;
 539         }
 540
 541         if (!persistant_swap_storage) {
 542                 swap_storage = shmem_file_setup("ttm swap",
 543                                                 ttm->num_pages << PAGE_SHIFT,
 544                                                 0);
 545                 if (unlikely(IS_ERR(swap_storage))) {
 546                         printk(KERN_ERR "Failed allocating swap storage.\n");
 547                         return PTR_ERR(swap_storage);
 548                 }
 549         } else
 550                 swap_storage = persistant_swap_storage;
 551
 552         swap_space = swap_storage->f_path.dentry->d_inode->i_mapping;
 553
 554         for (i = 0; i < ttm->num_pages; ++i) {
 555                 from_page = ttm->pages[i];
 556                 if (unlikely(from_page == NULL))
 557                         continue;
 558                 to_page = read_mapping_page(swap_space, i, NULL);
 559                 if (unlikely(IS_ERR(to_page))) {
 560                         ret = PTR_ERR(to_page);
 561                         goto out_err;
 562                 }
 563                 preempt_disable();
 564                 from_virtual = kmap_atomic(from_page, KM_USER0);
 565                 to_virtual = kmap_atomic(to_page, KM_USER1);
 566                 memcpy(to_virtual, from_virtual, PAGE_SIZE);
 567                 kunmap_atomic(to_virtual, KM_USER1);
 568                 kunmap_atomic(from_virtual, KM_USER0);
 569                 preempt_enable();
 570                 set_page_dirty(to_page);
 571                 mark_page_accessed(to_page);
 572                 page_cache_release(to_page);
 573         }
 574
 575         ttm_tt_free_alloced_pages(ttm);
 576         ttm->swap_storage = swap_storage;
 577         ttm->page_flags |= TTM_PAGE_FLAG_SWAPPED;
 578         if (persistant_swap_storage)
 579                 ttm->page_flags |= TTM_PAGE_FLAG_PERSISTANT_SWAP;
 580
 581         return 0;
 582 out_err:
 583         if (!persistant_swap_storage)
 584                 fput(swap_storage);
 585
 586         return ret;
 587 }