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