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