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_old,
 200                                           enum ttm_caching_state c_new)
 201 {
 202         int ret = 0;
 203
 204         if (PageHighMem(p))
 205                 return 0;
 206
 207         if (c_old != tt_cached) {
 208                 /* p isn't in the default caching state, set it to
 209                  * writeback first to free its current memtype. */
 210
 211                 ret = set_pages_wb(p, 1);
 212                 if (ret)
 213                         return ret;
 214         }
 215
 216         if (c_new == tt_wc)
 217                 ret = set_memory_wc((unsigned long) page_address(p), 1);
 218         else if (c_new == tt_uncached)
 219                 ret = set_pages_uc(p, 1);
 220
 221         return ret;
 222 }
 223 #else /* CONFIG_X86 */
 224 static inline int ttm_tt_set_page_caching(struct page *p,
 225                                           enum ttm_caching_state c_old,
 226                                           enum ttm_caching_state c_new)
 227 {
 228         return 0;
 229 }
 230 #endif /* CONFIG_X86 */
 231
 232 /*
 233  * Change caching policy for the linear kernel map
 234  * for range of pages in a ttm.
 235  */
 236
 237 static int ttm_tt_set_caching(struct ttm_tt *ttm,
 238                               enum ttm_caching_state c_state)
 239 {
 240         int i, j;
 241         struct page *cur_page;
 242         int ret;
 243
 244         if (ttm->caching_state == c_state)
 245                 return 0;
 246
 247         if (c_state != tt_cached) {
 248                 ret = ttm_tt_populate(ttm);
 249                 if (unlikely(ret != 0))
 250                         return ret;
 251         }
 252
 253         if (ttm->caching_state == tt_cached)
 254                 drm_clflush_pages(ttm->pages, ttm->num_pages);
 255
 256         for (i = 0; i < ttm->num_pages; ++i) {
 257                 cur_page = ttm->pages[i];
 258                 if (likely(cur_page != NULL)) {
 259                         ret = ttm_tt_set_page_caching(cur_page,
 260                                                       ttm->caching_state,
 261                                                       c_state);
 262                         if (unlikely(ret != 0))
 263                                 goto out_err;
 264                 }
 265         }
 266
 267         ttm->caching_state = c_state;
 268
 269         return 0;
 270
 271 out_err:
 272         for (j = 0; j < i; ++j) {
 273                 cur_page = ttm->pages[j];
 274                 if (likely(cur_page != NULL)) {
 275                         (void)ttm_tt_set_page_caching(cur_page, c_state,
 276                                                       ttm->caching_state);
 277                 }
 278         }
 279
 280         return ret;
 281 }
 282
 283 int ttm_tt_set_placement_caching(struct ttm_tt *ttm, uint32_t placement)
 284 {
 285         enum ttm_caching_state state;
 286
 287         if (placement & TTM_PL_FLAG_WC)
 288                 state = tt_wc;
 289         else if (placement & TTM_PL_FLAG_UNCACHED)
 290                 state = tt_uncached;
 291         else
 292                 state = tt_cached;
 293
 294         return ttm_tt_set_caching(ttm, state);
 295 }
 296 EXPORT_SYMBOL(ttm_tt_set_placement_caching);
 297
 298 static void ttm_tt_free_alloced_pages(struct ttm_tt *ttm)
 299 {
 300         int i;
 301         struct page *cur_page;
 302         struct ttm_backend *be = ttm->be;
 303
 304         if (be)
 305                 be->func->clear(be);
 306         (void)ttm_tt_set_caching(ttm, tt_cached);
 307         for (i = 0; i < ttm->num_pages; ++i) {
 308                 cur_page = ttm->pages[i];
 309                 ttm->pages[i] = NULL;
 310                 if (cur_page) {
 311                         if (page_count(cur_page) != 1)
 312                                 printk(KERN_ERR TTM_PFX
 313                                        "Erroneous page count. "
 314                                        "Leaking pages.\n");
 315                         ttm_mem_global_free_page(ttm->glob->mem_glob,
 316                                                  cur_page);
 317                         __free_page(cur_page);
 318                 }
 319         }
 320         ttm->state = tt_unpopulated;
 321         ttm->first_himem_page = ttm->num_pages;
 322         ttm->last_lomem_page = -1;
 323 }
 324
 325 void ttm_tt_destroy(struct ttm_tt *ttm)
 326 {
 327         struct ttm_backend *be;
 328
 329         if (unlikely(ttm == NULL))
 330                 return;
 331
 332         be = ttm->be;
 333         if (likely(be != NULL)) {
 334                 be->func->destroy(be);
 335                 ttm->be = NULL;
 336         }
 337
 338         if (likely(ttm->pages != NULL)) {
 339                 if (ttm->page_flags & TTM_PAGE_FLAG_USER)
 340                         ttm_tt_free_user_pages(ttm);
 341                 else
 342                         ttm_tt_free_alloced_pages(ttm);
 343
 344                 ttm_tt_free_page_directory(ttm);
 345         }
 346
 347         if (!(ttm->page_flags & TTM_PAGE_FLAG_PERSISTANT_SWAP) &&
 348             ttm->swap_storage)
 349                 fput(ttm->swap_storage);
 350
 351         kfree(ttm);
 352 }
 353
 354 int ttm_tt_set_user(struct ttm_tt *ttm,
 355                     struct task_struct *tsk,
 356                     unsigned long start, unsigned long num_pages)
 357 {
 358         struct mm_struct *mm = tsk->mm;
 359         int ret;
 360         int write = (ttm->page_flags & TTM_PAGE_FLAG_WRITE) != 0;
 361         struct ttm_mem_global *mem_glob = ttm->glob->mem_glob;
 362
 363         BUG_ON(num_pages != ttm->num_pages);
 364         BUG_ON((ttm->page_flags & TTM_PAGE_FLAG_USER) == 0);
 365
 366         /**
 367          * Account user pages as lowmem pages for now.
 368          */
 369
 370         ret = ttm_mem_global_alloc(mem_glob, num_pages * PAGE_SIZE,
 371                                    false, false);
 372         if (unlikely(ret != 0))
 373                 return ret;
 374
 375         down_read(&mm->mmap_sem);
 376         ret = get_user_pages(tsk, mm, start, num_pages,
 377                              write, 0, ttm->pages, NULL);
 378         up_read(&mm->mmap_sem);
 379
 380         if (ret != num_pages && write) {
 381                 ttm_tt_free_user_pages(ttm);
 382                 ttm_mem_global_free(mem_glob, num_pages * PAGE_SIZE);
 383                 return -ENOMEM;
 384         }
 385
 386         ttm->tsk = tsk;
 387         ttm->start = start;
 388         ttm->state = tt_unbound;
 389
 390         return 0;
 391 }
 392
 393 struct ttm_tt *ttm_tt_create(struct ttm_bo_device *bdev, unsigned long size,
 394                              uint32_t page_flags, struct page *dummy_read_page)
 395 {
 396         struct ttm_bo_driver *bo_driver = bdev->driver;
 397         struct ttm_tt *ttm;
 398
 399         if (!bo_driver)
 400                 return NULL;
 401
 402         ttm = kzalloc(sizeof(*ttm), GFP_KERNEL);
 403         if (!ttm)
 404                 return NULL;
 405
 406         ttm->glob = bdev->glob;
 407         ttm->num_pages = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
 408         ttm->first_himem_page = ttm->num_pages;
 409         ttm->last_lomem_page = -1;
 410         ttm->caching_state = tt_cached;
 411         ttm->page_flags = page_flags;
 412
 413         ttm->dummy_read_page = dummy_read_page;
 414
 415         ttm_tt_alloc_page_directory(ttm);
 416         if (!ttm->pages) {
 417                 ttm_tt_destroy(ttm);
 418                 printk(KERN_ERR TTM_PFX "Failed allocating page table\n");
 419                 return NULL;
 420         }
 421         ttm->be = bo_driver->create_ttm_backend_entry(bdev);
 422         if (!ttm->be) {
 423                 ttm_tt_destroy(ttm);
 424                 printk(KERN_ERR TTM_PFX "Failed creating ttm backend entry\n");
 425                 return NULL;
 426         }
 427         ttm->state = tt_unpopulated;
 428         return ttm;
 429 }
 430
 431 void ttm_tt_unbind(struct ttm_tt *ttm)
 432 {
 433         int ret;
 434         struct ttm_backend *be = ttm->be;
 435
 436         if (ttm->state == tt_bound) {
 437                 ret = be->func->unbind(be);
 438                 BUG_ON(ret);
 439                 ttm->state = tt_unbound;
 440         }
 441 }
 442
 443 int ttm_tt_bind(struct ttm_tt *ttm, struct ttm_mem_reg *bo_mem)
 444 {
 445         int ret = 0;
 446         struct ttm_backend *be;
 447
 448         if (!ttm)
 449                 return -EINVAL;
 450
 451         if (ttm->state == tt_bound)
 452                 return 0;
 453
 454         be = ttm->be;
 455
 456         ret = ttm_tt_populate(ttm);
 457         if (ret)
 458                 return ret;
 459
 460         ret = be->func->bind(be, bo_mem);
 461         if (ret) {
 462                 printk(KERN_ERR TTM_PFX "Couldn't bind backend.\n");
 463                 return ret;
 464         }
 465
 466         ttm->state = tt_bound;
 467
 468         if (ttm->page_flags & TTM_PAGE_FLAG_USER)
 469                 ttm->page_flags |= TTM_PAGE_FLAG_USER_DIRTY;
 470         return 0;
 471 }
 472 EXPORT_SYMBOL(ttm_tt_bind);
 473
 474 static int ttm_tt_swapin(struct ttm_tt *ttm)
 475 {
 476         struct address_space *swap_space;
 477         struct file *swap_storage;
 478         struct page *from_page;
 479         struct page *to_page;
 480         void *from_virtual;
 481         void *to_virtual;
 482         int i;
 483         int ret;
 484
 485         if (ttm->page_flags & TTM_PAGE_FLAG_USER) {
 486                 ret = ttm_tt_set_user(ttm, ttm->tsk, ttm->start,
 487                                       ttm->num_pages);
 488                 if (unlikely(ret != 0))
 489                         return ret;
 490
 491                 ttm->page_flags &= ~TTM_PAGE_FLAG_SWAPPED;
 492                 return 0;
 493         }
 494
 495         swap_storage = ttm->swap_storage;
 496         BUG_ON(swap_storage == NULL);
 497
 498         swap_space = swap_storage->f_path.dentry->d_inode->i_mapping;
 499
 500         for (i = 0; i < ttm->num_pages; ++i) {
 501                 from_page = read_mapping_page(swap_space, i, NULL);
 502                 if (IS_ERR(from_page))
 503                         goto out_err;
 504                 to_page = __ttm_tt_get_page(ttm, i);
 505                 if (unlikely(to_page == NULL))
 506                         goto out_err;
 507
 508                 preempt_disable();
 509                 from_virtual = kmap_atomic(from_page, KM_USER0);
 510                 to_virtual = kmap_atomic(to_page, KM_USER1);
 511                 memcpy(to_virtual, from_virtual, PAGE_SIZE);
 512                 kunmap_atomic(to_virtual, KM_USER1);
 513                 kunmap_atomic(from_virtual, KM_USER0);
 514                 preempt_enable();
 515                 page_cache_release(from_page);
 516         }
 517
 518         if (!(ttm->page_flags & TTM_PAGE_FLAG_PERSISTANT_SWAP))
 519                 fput(swap_storage);
 520         ttm->swap_storage = NULL;
 521         ttm->page_flags &= ~TTM_PAGE_FLAG_SWAPPED;
 522
 523         return 0;
 524 out_err:
 525         ttm_tt_free_alloced_pages(ttm);
 526         return -ENOMEM;
 527 }
 528
 529 int ttm_tt_swapout(struct ttm_tt *ttm, struct file *persistant_swap_storage)
 530 {
 531         struct address_space *swap_space;
 532         struct file *swap_storage;
 533         struct page *from_page;
 534         struct page *to_page;
 535         void *from_virtual;
 536         void *to_virtual;
 537         int i;
 538
 539         BUG_ON(ttm->state != tt_unbound && ttm->state != tt_unpopulated);
 540         BUG_ON(ttm->caching_state != tt_cached);
 541
 542         /*
 543          * For user buffers, just unpin the pages, as there should be
 544          * vma references.
 545          */
 546
 547         if (ttm->page_flags & TTM_PAGE_FLAG_USER) {
 548                 ttm_tt_free_user_pages(ttm);
 549                 ttm->page_flags |= TTM_PAGE_FLAG_SWAPPED;
 550                 ttm->swap_storage = NULL;
 551                 return 0;
 552         }
 553
 554         if (!persistant_swap_storage) {
 555                 swap_storage = shmem_file_setup("ttm swap",
 556                                                 ttm->num_pages << PAGE_SHIFT,
 557                                                 0);
 558                 if (unlikely(IS_ERR(swap_storage))) {
 559                         printk(KERN_ERR "Failed allocating swap storage.\n");
 560                         return -ENOMEM;
 561                 }
 562         } else
 563                 swap_storage = persistant_swap_storage;
 564
 565         swap_space = swap_storage->f_path.dentry->d_inode->i_mapping;
 566
 567         for (i = 0; i < ttm->num_pages; ++i) {
 568                 from_page = ttm->pages[i];
 569                 if (unlikely(from_page == NULL))
 570                         continue;
 571                 to_page = read_mapping_page(swap_space, i, NULL);
 572                 if (unlikely(to_page == NULL))
 573                         goto out_err;
 574
 575                 preempt_disable();
 576                 from_virtual = kmap_atomic(from_page, KM_USER0);
 577                 to_virtual = kmap_atomic(to_page, KM_USER1);
 578                 memcpy(to_virtual, from_virtual, PAGE_SIZE);
 579                 kunmap_atomic(to_virtual, KM_USER1);
 580                 kunmap_atomic(from_virtual, KM_USER0);
 581                 preempt_enable();
 582                 set_page_dirty(to_page);
 583                 mark_page_accessed(to_page);
 584                 page_cache_release(to_page);
 585         }
 586
 587         ttm_tt_free_alloced_pages(ttm);
 588         ttm->swap_storage = swap_storage;
 589         ttm->page_flags |= TTM_PAGE_FLAG_SWAPPED;
 590         if (persistant_swap_storage)
 591                 ttm->page_flags |= TTM_PAGE_FLAG_PERSISTANT_SWAP;
 592
 593         return 0;
 594 out_err:
 595         if (!persistant_swap_storage)
 596                 fput(swap_storage);
 597
 598         return -ENOMEM;
 599 }