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