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