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