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/vmalloc.h>
  32 #include <linux/sched.h>
  33 #include <linux/highmem.h>
  34 #include <linux/pagemap.h>
  35 #include <linux/file.h>
  36 #include <linux/swap.h>
  37 #include "ttm/ttm_module.h"
  38 #include "ttm/ttm_bo_driver.h"
  39 #include "ttm/ttm_placement.h"
  40
  41 static int ttm_tt_swapin(struct ttm_tt *ttm);
  42
  43 #if defined(CONFIG_X86)
  44 static void ttm_tt_clflush_page(struct page *page)
  45 {
  46         uint8_t *page_virtual;
  47         unsigned int i;
  48
  49         if (unlikely(page == NULL))
  50                 return;
  51
  52         page_virtual = kmap_atomic(page, KM_USER0);
  53
  54         for (i = 0; i < PAGE_SIZE; i += boot_cpu_data.x86_clflush_size)
  55                 clflush(page_virtual + i);
  56
  57         kunmap_atomic(page_virtual, KM_USER0);
  58 }
  59
  60 static void ttm_tt_cache_flush_clflush(struct page *pages[],
  61                                        unsigned long num_pages)
  62 {
  63         unsigned long i;
  64
  65         mb();
  66         for (i = 0; i < num_pages; ++i)
  67                 ttm_tt_clflush_page(*pages++);
  68         mb();
  69 }
  70 #elif !defined(__powerpc__)
  71 static void ttm_tt_ipi_handler(void *null)
  72 {
  73         ;
  74 }
  75 #endif
  76
  77 void ttm_tt_cache_flush(struct page *pages[], unsigned long num_pages)
  78 {
  79
  80 #if defined(CONFIG_X86)
  81         if (cpu_has_clflush) {
  82                 ttm_tt_cache_flush_clflush(pages, num_pages);
  83                 return;
  84         }
  85 #elif defined(__powerpc__)
  86         unsigned long i;
  87
  88         for (i = 0; i < num_pages; ++i) {
  89                 if (pages[i]) {
  90                         unsigned long start = (unsigned long)page_address(pages[i]);
  91                         flush_dcache_range(start, start + PAGE_SIZE);
  92                 }
  93         }
  94 #else
  95         if (on_each_cpu(ttm_tt_ipi_handler, NULL, 1) != 0)
  96                 printk(KERN_ERR TTM_PFX
  97                        "Timed out waiting for drm cache flush.\n");
  98 #endif
  99 }
 100
 101 /**
 102  * Allocates storage for pointers to the pages that back the ttm.
 103  *
 104  * Uses kmalloc if possible. Otherwise falls back to vmalloc.
 105  */
 106 static void ttm_tt_alloc_page_directory(struct ttm_tt *ttm)
 107 {
 108         unsigned long size = ttm->num_pages * sizeof(*ttm->pages);
 109         ttm->pages = NULL;
 110
 111         if (size <= PAGE_SIZE)
 112                 ttm->pages = kzalloc(size, GFP_KERNEL);
 113
 114         if (!ttm->pages) {
 115                 ttm->pages = vmalloc_user(size);
 116                 if (ttm->pages)
 117                         ttm->page_flags |= TTM_PAGE_FLAG_VMALLOC;
 118         }
 119 }
 120
 121 static void ttm_tt_free_page_directory(struct ttm_tt *ttm)
 122 {
 123         if (ttm->page_flags & TTM_PAGE_FLAG_VMALLOC) {
 124                 vfree(ttm->pages);
 125                 ttm->page_flags &= ~TTM_PAGE_FLAG_VMALLOC;
 126         } else {
 127                 kfree(ttm->pages);
 128         }
 129         ttm->pages = NULL;
 130 }
 131
 132 static struct page *ttm_tt_alloc_page(unsigned page_flags)
 133 {
 134         gfp_t gfp_flags = GFP_HIGHUSER;
 135
 136         if (page_flags & TTM_PAGE_FLAG_ZERO_ALLOC)
 137                 gfp_flags |= __GFP_ZERO;
 138
 139         if (page_flags & TTM_PAGE_FLAG_DMA32)
 140                 gfp_flags |= __GFP_DMA32;
 141
 142         return alloc_page(gfp_flags);
 143 }
 144
 145 static void ttm_tt_free_user_pages(struct ttm_tt *ttm)
 146 {
 147         int write;
 148         int dirty;
 149         struct page *page;
 150         int i;
 151         struct ttm_backend *be = ttm->be;
 152
 153         BUG_ON(!(ttm->page_flags & TTM_PAGE_FLAG_USER));
 154         write = ((ttm->page_flags & TTM_PAGE_FLAG_WRITE) != 0);
 155         dirty = ((ttm->page_flags & TTM_PAGE_FLAG_USER_DIRTY) != 0);
 156
 157         if (be)
 158                 be->func->clear(be);
 159
 160         for (i = 0; i < ttm->num_pages; ++i) {
 161                 page = ttm->pages[i];
 162                 if (page == NULL)
 163                         continue;
 164
 165                 if (page == ttm->dummy_read_page) {
 166                         BUG_ON(write);
 167                         continue;
 168                 }
 169
 170                 if (write && dirty && !PageReserved(page))
 171                         set_page_dirty_lock(page);
 172
 173                 ttm->pages[i] = NULL;
 174                 ttm_mem_global_free(ttm->bdev->mem_glob, PAGE_SIZE, false);
 175                 put_page(page);
 176         }
 177         ttm->state = tt_unpopulated;
 178         ttm->first_himem_page = ttm->num_pages;
 179         ttm->last_lomem_page = -1;
 180 }
 181
 182 static struct page *__ttm_tt_get_page(struct ttm_tt *ttm, int index)
 183 {
 184         struct page *p;
 185         struct ttm_bo_device *bdev = ttm->bdev;
 186         struct ttm_mem_global *mem_glob = bdev->mem_glob;
 187         int ret;
 188
 189         while (NULL == (p = ttm->pages[index])) {
 190                 p = ttm_tt_alloc_page(ttm->page_flags);
 191
 192                 if (!p)
 193                         return NULL;
 194
 195                 if (PageHighMem(p)) {
 196                         ret =
 197                             ttm_mem_global_alloc(mem_glob, PAGE_SIZE,
 198                                                  false, false, true);
 199                         if (unlikely(ret != 0))
 200                                 goto out_err;
 201                         ttm->pages[--ttm->first_himem_page] = p;
 202                 } else {
 203                         ret =
 204                             ttm_mem_global_alloc(mem_glob, PAGE_SIZE,
 205                                                  false, false, false);
 206                         if (unlikely(ret != 0))
 207                                 goto out_err;
 208                         ttm->pages[++ttm->last_lomem_page] = p;
 209                 }
 210         }
 211         return p;
 212 out_err:
 213         put_page(p);
 214         return NULL;
 215 }
 216
 217 struct page *ttm_tt_get_page(struct ttm_tt *ttm, int index)
 218 {
 219         int ret;
 220
 221         if (unlikely(ttm->page_flags & TTM_PAGE_FLAG_SWAPPED)) {
 222                 ret = ttm_tt_swapin(ttm);
 223                 if (unlikely(ret != 0))
 224                         return NULL;
 225         }
 226         return __ttm_tt_get_page(ttm, index);
 227 }
 228
 229 int ttm_tt_populate(struct ttm_tt *ttm)
 230 {
 231         struct page *page;
 232         unsigned long i;
 233         struct ttm_backend *be;
 234         int ret;
 235
 236         if (ttm->state != tt_unpopulated)
 237                 return 0;
 238
 239         if (unlikely(ttm->page_flags & TTM_PAGE_FLAG_SWAPPED)) {
 240                 ret = ttm_tt_swapin(ttm);
 241                 if (unlikely(ret != 0))
 242                         return ret;
 243         }
 244
 245         be = ttm->be;
 246
 247         for (i = 0; i < ttm->num_pages; ++i) {
 248                 page = __ttm_tt_get_page(ttm, i);
 249                 if (!page)
 250                         return -ENOMEM;
 251         }
 252
 253         be->func->populate(be, ttm->num_pages, ttm->pages,
 254                            ttm->dummy_read_page);
 255         ttm->state = tt_unbound;
 256         return 0;
 257 }
 258
 259 #ifdef CONFIG_X86
 260 static inline int ttm_tt_set_page_caching(struct page *p,
 261                                           enum ttm_caching_state c_state)
 262 {
 263         if (PageHighMem(p))
 264                 return 0;
 265
 266         switch (c_state) {
 267         case tt_cached:
 268                 return set_pages_wb(p, 1);
 269         case tt_wc:
 270             return set_memory_wc((unsigned long) page_address(p), 1);
 271         default:
 272                 return set_pages_uc(p, 1);
 273         }
 274 }
 275 #else /* CONFIG_X86 */
 276 static inline int ttm_tt_set_page_caching(struct page *p,
 277                                           enum ttm_caching_state c_state)
 278 {
 279         return 0;
 280 }
 281 #endif /* CONFIG_X86 */
 282
 283 /*
 284  * Change caching policy for the linear kernel map
 285  * for range of pages in a ttm.
 286  */
 287
 288 static int ttm_tt_set_caching(struct ttm_tt *ttm,
 289                               enum ttm_caching_state c_state)
 290 {
 291         int i, j;
 292         struct page *cur_page;
 293         int ret;
 294
 295         if (ttm->caching_state == c_state)
 296                 return 0;
 297
 298         if (c_state != tt_cached) {
 299                 ret = ttm_tt_populate(ttm);
 300                 if (unlikely(ret != 0))
 301                         return ret;
 302         }
 303
 304         if (ttm->caching_state == tt_cached)
 305                 ttm_tt_cache_flush(ttm->pages, ttm->num_pages);
 306
 307         for (i = 0; i < ttm->num_pages; ++i) {
 308                 cur_page = ttm->pages[i];
 309                 if (likely(cur_page != NULL)) {
 310                         ret = ttm_tt_set_page_caching(cur_page, c_state);
 311                         if (unlikely(ret != 0))
 312                                 goto out_err;
 313                 }
 314         }
 315
 316         ttm->caching_state = c_state;
 317
 318         return 0;
 319
 320 out_err:
 321         for (j = 0; j < i; ++j) {
 322                 cur_page = ttm->pages[j];
 323                 if (likely(cur_page != NULL)) {
 324                         (void)ttm_tt_set_page_caching(cur_page,
 325                                                       ttm->caching_state);
 326                 }
 327         }
 328
 329         return ret;
 330 }
 331
 332 int ttm_tt_set_placement_caching(struct ttm_tt *ttm, uint32_t placement)
 333 {
 334         enum ttm_caching_state state;
 335
 336         if (placement & TTM_PL_FLAG_WC)
 337                 state = tt_wc;
 338         else if (placement & TTM_PL_FLAG_UNCACHED)
 339                 state = tt_uncached;
 340         else
 341                 state = tt_cached;
 342
 343         return ttm_tt_set_caching(ttm, state);
 344 }
 345
 346 static void ttm_tt_free_alloced_pages(struct ttm_tt *ttm)
 347 {
 348         int i;
 349         struct page *cur_page;
 350         struct ttm_backend *be = ttm->be;
 351
 352         if (be)
 353                 be->func->clear(be);
 354         (void)ttm_tt_set_caching(ttm, tt_cached);
 355         for (i = 0; i < ttm->num_pages; ++i) {
 356                 cur_page = ttm->pages[i];
 357                 ttm->pages[i] = NULL;
 358                 if (cur_page) {
 359                         if (page_count(cur_page) != 1)
 360                                 printk(KERN_ERR TTM_PFX
 361                                        "Erroneous page count. "
 362                                        "Leaking pages.\n");
 363                         ttm_mem_global_free(ttm->bdev->mem_glob, PAGE_SIZE,
 364                                             PageHighMem(cur_page));
 365                         __free_page(cur_page);
 366                 }
 367         }
 368         ttm->state = tt_unpopulated;
 369         ttm->first_himem_page = ttm->num_pages;
 370         ttm->last_lomem_page = -1;
 371 }
 372
 373 void ttm_tt_destroy(struct ttm_tt *ttm)
 374 {
 375         struct ttm_backend *be;
 376
 377         if (unlikely(ttm == NULL))
 378                 return;
 379
 380         be = ttm->be;
 381         if (likely(be != NULL)) {
 382                 be->func->destroy(be);
 383                 ttm->be = NULL;
 384         }
 385
 386         if (likely(ttm->pages != NULL)) {
 387                 if (ttm->page_flags & TTM_PAGE_FLAG_USER)
 388                         ttm_tt_free_user_pages(ttm);
 389                 else
 390                         ttm_tt_free_alloced_pages(ttm);
 391
 392                 ttm_tt_free_page_directory(ttm);
 393         }
 394
 395         if (!(ttm->page_flags & TTM_PAGE_FLAG_PERSISTANT_SWAP) &&
 396             ttm->swap_storage)
 397                 fput(ttm->swap_storage);
 398
 399         kfree(ttm);
 400 }
 401
 402 int ttm_tt_set_user(struct ttm_tt *ttm,
 403                     struct task_struct *tsk,
 404                     unsigned long start, unsigned long num_pages)
 405 {
 406         struct mm_struct *mm = tsk->mm;
 407         int ret;
 408         int write = (ttm->page_flags & TTM_PAGE_FLAG_WRITE) != 0;
 409         struct ttm_mem_global *mem_glob = ttm->bdev->mem_glob;
 410
 411         BUG_ON(num_pages != ttm->num_pages);
 412         BUG_ON((ttm->page_flags & TTM_PAGE_FLAG_USER) == 0);
 413
 414         /**
 415          * Account user pages as lowmem pages for now.
 416          */
 417
 418         ret = ttm_mem_global_alloc(mem_glob, num_pages * PAGE_SIZE,
 419                                    false, false, false);
 420         if (unlikely(ret != 0))
 421                 return ret;
 422
 423         down_read(&mm->mmap_sem);
 424         ret = get_user_pages(tsk, mm, start, num_pages,
 425                              write, 0, ttm->pages, NULL);
 426         up_read(&mm->mmap_sem);
 427
 428         if (ret != num_pages && write) {
 429                 ttm_tt_free_user_pages(ttm);
 430                 ttm_mem_global_free(mem_glob, num_pages * PAGE_SIZE, false);
 431                 return -ENOMEM;
 432         }
 433
 434         ttm->tsk = tsk;
 435         ttm->start = start;
 436         ttm->state = tt_unbound;
 437
 438         return 0;
 439 }
 440
 441 struct ttm_tt *ttm_tt_create(struct ttm_bo_device *bdev, unsigned long size,
 442                              uint32_t page_flags, struct page *dummy_read_page)
 443 {
 444         struct ttm_bo_driver *bo_driver = bdev->driver;
 445         struct ttm_tt *ttm;
 446
 447         if (!bo_driver)
 448                 return NULL;
 449
 450         ttm = kzalloc(sizeof(*ttm), GFP_KERNEL);
 451         if (!ttm)
 452                 return NULL;
 453
 454         ttm->bdev = bdev;
 455
 456         ttm->num_pages = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
 457         ttm->first_himem_page = ttm->num_pages;
 458         ttm->last_lomem_page = -1;
 459         ttm->caching_state = tt_cached;
 460         ttm->page_flags = page_flags;
 461
 462         ttm->dummy_read_page = dummy_read_page;
 463
 464         ttm_tt_alloc_page_directory(ttm);
 465         if (!ttm->pages) {
 466                 ttm_tt_destroy(ttm);
 467                 printk(KERN_ERR TTM_PFX "Failed allocating page table\n");
 468                 return NULL;
 469         }
 470         ttm->be = bo_driver->create_ttm_backend_entry(bdev);
 471         if (!ttm->be) {
 472                 ttm_tt_destroy(ttm);
 473                 printk(KERN_ERR TTM_PFX "Failed creating ttm backend entry\n");
 474                 return NULL;
 475         }
 476         ttm->state = tt_unpopulated;
 477         return ttm;
 478 }
 479
 480 void ttm_tt_unbind(struct ttm_tt *ttm)
 481 {
 482         int ret;
 483         struct ttm_backend *be = ttm->be;
 484
 485         if (ttm->state == tt_bound) {
 486                 ret = be->func->unbind(be);
 487                 BUG_ON(ret);
 488                 ttm->state = tt_unbound;
 489         }
 490 }
 491
 492 int ttm_tt_bind(struct ttm_tt *ttm, struct ttm_mem_reg *bo_mem)
 493 {
 494         int ret = 0;
 495         struct ttm_backend *be;
 496
 497         if (!ttm)
 498                 return -EINVAL;
 499
 500         if (ttm->state == tt_bound)
 501                 return 0;
 502
 503         be = ttm->be;
 504
 505         ret = ttm_tt_populate(ttm);
 506         if (ret)
 507                 return ret;
 508
 509         ret = be->func->bind(be, bo_mem);
 510         if (ret) {
 511                 printk(KERN_ERR TTM_PFX "Couldn't bind backend.\n");
 512                 return ret;
 513         }
 514
 515         ttm->state = tt_bound;
 516
 517         if (ttm->page_flags & TTM_PAGE_FLAG_USER)
 518                 ttm->page_flags |= TTM_PAGE_FLAG_USER_DIRTY;
 519         return 0;
 520 }
 521 EXPORT_SYMBOL(ttm_tt_bind);
 522
 523 static int ttm_tt_swapin(struct ttm_tt *ttm)
 524 {
 525         struct address_space *swap_space;
 526         struct file *swap_storage;
 527         struct page *from_page;
 528         struct page *to_page;
 529         void *from_virtual;
 530         void *to_virtual;
 531         int i;
 532         int ret;
 533
 534         if (ttm->page_flags & TTM_PAGE_FLAG_USER) {
 535                 ret = ttm_tt_set_user(ttm, ttm->tsk, ttm->start,
 536                                       ttm->num_pages);
 537                 if (unlikely(ret != 0))
 538                         return ret;
 539
 540                 ttm->page_flags &= ~TTM_PAGE_FLAG_SWAPPED;
 541                 return 0;
 542         }
 543
 544         swap_storage = ttm->swap_storage;
 545         BUG_ON(swap_storage == NULL);
 546
 547         swap_space = swap_storage->f_path.dentry->d_inode->i_mapping;
 548
 549         for (i = 0; i < ttm->num_pages; ++i) {
 550                 from_page = read_mapping_page(swap_space, i, NULL);
 551                 if (IS_ERR(from_page))
 552                         goto out_err;
 553                 to_page = __ttm_tt_get_page(ttm, i);
 554                 if (unlikely(to_page == NULL))
 555                         goto out_err;
 556
 557                 preempt_disable();
 558                 from_virtual = kmap_atomic(from_page, KM_USER0);
 559                 to_virtual = kmap_atomic(to_page, KM_USER1);
 560                 memcpy(to_virtual, from_virtual, PAGE_SIZE);
 561                 kunmap_atomic(to_virtual, KM_USER1);
 562                 kunmap_atomic(from_virtual, KM_USER0);
 563                 preempt_enable();
 564                 page_cache_release(from_page);
 565         }
 566
 567         if (!(ttm->page_flags & TTM_PAGE_FLAG_PERSISTANT_SWAP))
 568                 fput(swap_storage);
 569         ttm->swap_storage = NULL;
 570         ttm->page_flags &= ~TTM_PAGE_FLAG_SWAPPED;
 571
 572         return 0;
 573 out_err:
 574         ttm_tt_free_alloced_pages(ttm);
 575         return -ENOMEM;
 576 }
 577
 578 int ttm_tt_swapout(struct ttm_tt *ttm, struct file *persistant_swap_storage)
 579 {
 580         struct address_space *swap_space;
 581         struct file *swap_storage;
 582         struct page *from_page;
 583         struct page *to_page;
 584         void *from_virtual;
 585         void *to_virtual;
 586         int i;
 587
 588         BUG_ON(ttm->state != tt_unbound && ttm->state != tt_unpopulated);
 589         BUG_ON(ttm->caching_state != tt_cached);
 590
 591         /*
 592          * For user buffers, just unpin the pages, as there should be
 593          * vma references.
 594          */
 595
 596         if (ttm->page_flags & TTM_PAGE_FLAG_USER) {
 597                 ttm_tt_free_user_pages(ttm);
 598                 ttm->page_flags |= TTM_PAGE_FLAG_SWAPPED;
 599                 ttm->swap_storage = NULL;
 600                 return 0;
 601         }
 602
 603         if (!persistant_swap_storage) {
 604                 swap_storage = shmem_file_setup("ttm swap",
 605                                                 ttm->num_pages << PAGE_SHIFT,
 606                                                 0);
 607                 if (unlikely(IS_ERR(swap_storage))) {
 608                         printk(KERN_ERR "Failed allocating swap storage.\n");
 609                         return -ENOMEM;
 610                 }
 611         } else
 612                 swap_storage = persistant_swap_storage;
 613
 614         swap_space = swap_storage->f_path.dentry->d_inode->i_mapping;
 615
 616         for (i = 0; i < ttm->num_pages; ++i) {
 617                 from_page = ttm->pages[i];
 618                 if (unlikely(from_page == NULL))
 619                         continue;
 620                 to_page = read_mapping_page(swap_space, i, NULL);
 621                 if (unlikely(to_page == NULL))
 622                         goto out_err;
 623
 624                 preempt_disable();
 625                 from_virtual = kmap_atomic(from_page, KM_USER0);
 626                 to_virtual = kmap_atomic(to_page, KM_USER1);
 627                 memcpy(to_virtual, from_virtual, PAGE_SIZE);
 628                 kunmap_atomic(to_virtual, KM_USER1);
 629                 kunmap_atomic(from_virtual, KM_USER0);
 630                 preempt_enable();
 631                 set_page_dirty(to_page);
 632                 mark_page_accessed(to_page);
 633                 page_cache_release(to_page);
 634         }
 635
 636         ttm_tt_free_alloced_pages(ttm);
 637         ttm->swap_storage = swap_storage;
 638         ttm->page_flags |= TTM_PAGE_FLAG_SWAPPED;
 639         if (persistant_swap_storage)
 640                 ttm->page_flags |= TTM_PAGE_FLAG_PERSISTANT_SWAP;
 641
 642         return 0;
 643 out_err:
 644         if (!persistant_swap_storage)
 645                 fput(swap_storage);
 646
 647         return -ENOMEM;
 648 }