linux-core/drm_ttm.c

   1 /**************************************************************************
   2  *
   3  * Copyright (c) 2006-2007 Tungsten Graphics, Inc., Cedar Park, TX., 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 Hellström <thomas-at-tungstengraphics-dot-com>
  29  */
  30
  31 #include "drmP.h"
  32
  33 #if defined( CONFIG_X86 ) && (LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,24))
  34 static void drm_clflush_page(struct page *page)
  35 {
  36         uint8_t *page_virtual;
  37         unsigned int i;
  38
  39         if (unlikely(page == NULL))
  40                 return;
  41
  42         page_virtual = kmap_atomic(page, KM_USER0);
  43
  44         for (i=0; i < PAGE_SIZE; i += boot_cpu_data.x86_clflush_size)
  45                 clflush(page_virtual + i);
  46
  47         kunmap_atomic(page_virtual, KM_USER0);
  48 }
  49
  50 static void drm_ttm_cache_flush_clflush(struct page *pages[], unsigned long num_pages)
  51 {
  52         unsigned long i;
  53
  54         mb();
  55         for (i=0; i < num_pages; ++i)
  56                 drm_clflush_page(*pages++);
  57         mb();
  58 }
  59 #endif
  60
  61 static void drm_ttm_ipi_handler(void *null)
  62 {
  63         flush_agp_cache();
  64 }
  65
  66 void drm_ttm_cache_flush(struct page *pages[], unsigned long num_pages)
  67 {
  68
  69 #if defined( CONFIG_X86 ) && (LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,24))
  70         if (cpu_has_clflush) {
  71                 drm_ttm_cache_flush_clflush(pages, num_pages);
  72                 return;
  73         }
  74 #endif
  75         if (on_each_cpu(drm_ttm_ipi_handler, NULL, 1, 1) != 0)
  76                 DRM_ERROR("Timed out waiting for drm cache flush.\n");
  77 }
  78 EXPORT_SYMBOL(drm_ttm_cache_flush);
  79
  80 /**
  81  * Allocates storage for pointers to the pages that back the ttm.
  82  *
  83  * Uses kmalloc if possible. Otherwise falls back to vmalloc.
  84  */
  85 static void drm_ttm_alloc_page_directory(struct drm_ttm *ttm)
  86 {
  87         unsigned long size = ttm->num_pages * sizeof(*ttm->pages);
  88         ttm->pages = NULL;
  89
  90         if (drm_alloc_memctl(size))
  91                 return;
  92
  93         if (size <= PAGE_SIZE)
  94                 ttm->pages = drm_calloc(1, size, DRM_MEM_TTM);
  95
  96         if (!ttm->pages) {
  97                 ttm->pages = vmalloc_user(size);
  98                 if (ttm->pages)
  99                         ttm->page_flags |= DRM_TTM_PAGEDIR_VMALLOC;
 100         }
 101         if (!ttm->pages)
 102                 drm_free_memctl(size);
 103 }
 104
 105 static void drm_ttm_free_page_directory(struct drm_ttm *ttm)
 106 {
 107         unsigned long size = ttm->num_pages * sizeof(*ttm->pages);
 108
 109         if (ttm->page_flags & DRM_TTM_PAGEDIR_VMALLOC) {
 110                 vfree(ttm->pages);
 111                 ttm->page_flags &= ~DRM_TTM_PAGEDIR_VMALLOC;
 112         } else {
 113                 drm_free(ttm->pages, size, DRM_MEM_TTM);
 114         }
 115         drm_free_memctl(size);
 116         ttm->pages = NULL;
 117 }
 118
 119 static struct page *drm_ttm_alloc_page(void)
 120 {
 121         struct page *page;
 122
 123         if (drm_alloc_memctl(PAGE_SIZE))
 124                 return NULL;
 125
 126         page = alloc_page(GFP_KERNEL | __GFP_ZERO | GFP_DMA32);
 127         if (!page) {
 128                 drm_free_memctl(PAGE_SIZE);
 129                 return NULL;
 130         }
 131 #if (LINUX_VERSION_CODE < KERNEL_VERSION(2,6,15))
 132         SetPageReserved(page);
 133 #endif
 134         return page;
 135 }
 136
 137 /*
 138  * Change caching policy for the linear kernel map
 139  * for range of pages in a ttm.
 140  */
 141
 142 static int drm_ttm_set_caching(struct drm_ttm *ttm, int noncached)
 143 {
 144         int i;
 145         struct page **cur_page;
 146         int do_tlbflush = 0;
 147
 148         if ((ttm->page_flags & DRM_TTM_PAGE_UNCACHED) == noncached)
 149                 return 0;
 150
 151         if (noncached)
 152                 drm_ttm_cache_flush(ttm->pages, ttm->num_pages);
 153
 154         for (i = 0; i < ttm->num_pages; ++i) {
 155                 cur_page = ttm->pages + i;
 156                 if (*cur_page) {
 157                         if (!PageHighMem(*cur_page)) {
 158                                 if (noncached) {
 159                                         map_page_into_agp(*cur_page);
 160                                 } else {
 161                                         unmap_page_from_agp(*cur_page);
 162                                 }
 163                                 do_tlbflush = 1;
 164                         }
 165                 }
 166         }
 167         if (do_tlbflush)
 168                 flush_agp_mappings();
 169
 170         DRM_FLAG_MASKED(ttm->page_flags, noncached, DRM_TTM_PAGE_UNCACHED);
 171
 172         return 0;
 173 }
 174
 175
 176 static void drm_ttm_free_user_pages(struct drm_ttm *ttm)
 177 {
 178         int write;
 179         int dirty;
 180         struct page *page;
 181         int i;
 182
 183         BUG_ON(!(ttm->page_flags & DRM_TTM_PAGE_USER));
 184         write = ((ttm->page_flags & DRM_TTM_PAGE_WRITE) != 0);
 185         dirty = ((ttm->page_flags & DRM_TTM_PAGE_USER_DIRTY) != 0);
 186
 187         for (i = 0; i < ttm->num_pages; ++i) {
 188                 page = ttm->pages[i];
 189                 if (page == NULL)
 190                         continue;
 191
 192                 if (page == ttm->dummy_read_page) {
 193                         BUG_ON(write);
 194                         continue;
 195                 }
 196
 197                 if (write && dirty && !PageReserved(page))
 198                         set_page_dirty_lock(page);
 199
 200                 ttm->pages[i] = NULL;
 201                 put_page(page);
 202         }
 203 }
 204
 205 static void drm_ttm_free_alloced_pages(struct drm_ttm *ttm)
 206 {
 207         int i;
 208         struct drm_buffer_manager *bm = &ttm->dev->bm;
 209         struct page **cur_page;
 210
 211         for (i = 0; i < ttm->num_pages; ++i) {
 212                 cur_page = ttm->pages + i;
 213                 if (*cur_page) {
 214 #if (LINUX_VERSION_CODE < KERNEL_VERSION(2,6,15))
 215                         ClearPageReserved(*cur_page);
 216 #endif
 217                         if (page_count(*cur_page) != 1)
 218                                 DRM_ERROR("Erroneous page count. Leaking pages.\n");
 219                         if (page_mapped(*cur_page))
 220                                 DRM_ERROR("Erroneous map count. Leaking page mappings.\n");
 221                         __free_page(*cur_page);
 222                         drm_free_memctl(PAGE_SIZE);
 223                         --bm->cur_pages;
 224                 }
 225         }
 226 }
 227
 228 /*
 229  * Free all resources associated with a ttm.
 230  */
 231
 232 int drm_ttm_destroy(struct drm_ttm *ttm)
 233 {
 234         struct drm_ttm_backend *be;
 235
 236         if (!ttm)
 237                 return 0;
 238
 239         be = ttm->be;
 240         if (be) {
 241                 be->func->destroy(be);
 242                 ttm->be = NULL;
 243         }
 244
 245         if (ttm->pages) {
 246                 if (ttm->page_flags & DRM_TTM_PAGE_UNCACHED)
 247                         drm_ttm_set_caching(ttm, 0);
 248
 249                 if (ttm->page_flags & DRM_TTM_PAGE_USER)
 250                         drm_ttm_free_user_pages(ttm);
 251                 else
 252                         drm_ttm_free_alloced_pages(ttm);
 253
 254                 drm_ttm_free_page_directory(ttm);
 255         }
 256
 257         drm_ctl_free(ttm, sizeof(*ttm), DRM_MEM_TTM);
 258         return 0;
 259 }
 260
 261 struct page *drm_ttm_get_page(struct drm_ttm *ttm, int index)
 262 {
 263         struct page *p;
 264         struct drm_buffer_manager *bm = &ttm->dev->bm;
 265
 266         while(NULL == (p = ttm->pages[index])) {
 267                 p = drm_ttm_alloc_page();
 268                 if (!p)
 269                         return NULL;
 270
 271                 if (PageHighMem(p))
 272                         ttm->pages[--ttm->first_himem_page] = p;
 273                 else
 274                         ttm->pages[++ttm->last_lomem_page] = p;
 275
 276                 ++bm->cur_pages;
 277         }
 278         return p;
 279 }
 280 EXPORT_SYMBOL(drm_ttm_get_page);
 281
 282 /**
 283  * drm_ttm_set_user:
 284  *
 285  * @ttm: the ttm to map pages to. This must always be
 286  * a freshly created ttm.
 287  *
 288  * @tsk: a pointer to the address space from which to map
 289  * pages.
 290  *
 291  * @write: a boolean indicating that write access is desired
 292  *
 293  * start: the starting address
 294  *
 295  * Map a range of user addresses to a new ttm object. This
 296  * provides access to user memory from the graphics device.
 297  */
 298 int drm_ttm_set_user(struct drm_ttm *ttm,
 299                      struct task_struct *tsk,
 300                      unsigned long start,
 301                      unsigned long num_pages)
 302 {
 303         struct mm_struct *mm = tsk->mm;
 304         int ret;
 305         int write = (ttm->page_flags & DRM_TTM_PAGE_WRITE) != 0;
 306
 307         BUG_ON(num_pages != ttm->num_pages);
 308         BUG_ON((ttm->page_flags & DRM_TTM_PAGE_USER) == 0);
 309
 310         down_read(&mm->mmap_sem);
 311         ret = get_user_pages(tsk, mm, start, num_pages,
 312                              write, 0, ttm->pages, NULL);
 313         up_read(&mm->mmap_sem);
 314
 315         if (ret != num_pages && write) {
 316                 drm_ttm_free_user_pages(ttm);
 317                 return -ENOMEM;
 318         }
 319
 320         return 0;
 321 }
 322
 323 /**
 324  * drm_ttm_populate:
 325  *
 326  * @ttm: the object to allocate pages for
 327  *
 328  * Allocate pages for all unset page entries, then
 329  * call the backend to create the hardware mappings
 330  */
 331 int drm_ttm_populate(struct drm_ttm *ttm)
 332 {
 333         struct page *page;
 334         unsigned long i;
 335         struct drm_ttm_backend *be;
 336
 337         if (ttm->state != ttm_unpopulated)
 338                 return 0;
 339
 340         be = ttm->be;
 341
 342         for (i = 0; i < ttm->num_pages; ++i) {
 343                 page = drm_ttm_get_page(ttm, i);
 344                 if (!page)
 345                         return -ENOMEM;
 346         }
 347
 348         be->func->populate(be, ttm->num_pages, ttm->pages, ttm->dummy_read_page);
 349         ttm->state = ttm_unbound;
 350         return 0;
 351 }
 352
 353 /**
 354  * drm_ttm_create:
 355  *
 356  * @dev: the drm_device
 357  *
 358  * @size: The size (in bytes) of the desired object
 359  *
 360  * @page_flags: various DRM_TTM_PAGE_* flags. See drm_object.h.
 361  *
 362  * Allocate and initialize a ttm, leaving it unpopulated at this time
 363  */
 364
 365 struct drm_ttm *drm_ttm_create(struct drm_device *dev, unsigned long size,
 366                                uint32_t page_flags, struct page *dummy_read_page)
 367 {
 368         struct drm_bo_driver *bo_driver = dev->driver->bo_driver;
 369         struct drm_ttm *ttm;
 370
 371         if (!bo_driver)
 372                 return NULL;
 373
 374         ttm = drm_ctl_calloc(1, sizeof(*ttm), DRM_MEM_TTM);
 375         if (!ttm)
 376                 return NULL;
 377
 378         ttm->dev = dev;
 379         atomic_set(&ttm->vma_count, 0);
 380
 381         ttm->destroy = 0;
 382         ttm->num_pages = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
 383         ttm->first_himem_page = ttm->num_pages;
 384         ttm->last_lomem_page = -1;
 385
 386         ttm->page_flags = page_flags;
 387
 388         ttm->dummy_read_page = dummy_read_page;
 389
 390         /*
 391          * Account also for AGP module memory usage.
 392          */
 393
 394         drm_ttm_alloc_page_directory(ttm);
 395         if (!ttm->pages) {
 396                 drm_ttm_destroy(ttm);
 397                 DRM_ERROR("Failed allocating page table\n");
 398                 return NULL;
 399         }
 400         ttm->be = bo_driver->create_ttm_backend_entry(dev);
 401         if (!ttm->be) {
 402                 drm_ttm_destroy(ttm);
 403                 DRM_ERROR("Failed creating ttm backend entry\n");
 404                 return NULL;
 405         }
 406         ttm->state = ttm_unpopulated;
 407         return ttm;
 408 }
 409
 410 /**
 411  * drm_ttm_evict:
 412  *
 413  * @ttm: the object to be unbound from the aperture.
 414  *
 415  * Transition a ttm from bound to evicted, where it
 416  * isn't present in the aperture, but various caches may
 417  * not be consistent.
 418  */
 419 void drm_ttm_evict(struct drm_ttm *ttm)
 420 {
 421         struct drm_ttm_backend *be = ttm->be;
 422         int ret;
 423
 424         if (ttm->state == ttm_bound) {
 425                 ret = be->func->unbind(be);
 426                 BUG_ON(ret);
 427         }
 428
 429         ttm->state = ttm_evicted;
 430 }
 431
 432 /**
 433  * drm_ttm_fixup_caching:
 434  *
 435  * @ttm: the object to set unbound
 436  *
 437  * XXX this function is misnamed. Transition a ttm from evicted to
 438  * unbound, flushing caches as appropriate.
 439  */
 440 void drm_ttm_fixup_caching(struct drm_ttm *ttm)
 441 {
 442
 443         if (ttm->state == ttm_evicted) {
 444                 struct drm_ttm_backend *be = ttm->be;
 445                 if (be->func->needs_ub_cache_adjust(be))
 446                         drm_ttm_set_caching(ttm, 0);
 447                 ttm->state = ttm_unbound;
 448         }
 449 }
 450
 451 /**
 452  * drm_ttm_unbind:
 453  *
 454  * @ttm: the object to unbind from the graphics device
 455  *
 456  * Unbind an object from the aperture. This removes the mappings
 457  * from the graphics device and flushes caches if necessary.
 458  */
 459 void drm_ttm_unbind(struct drm_ttm *ttm)
 460 {
 461         if (ttm->state == ttm_bound)
 462                 drm_ttm_evict(ttm);
 463
 464         drm_ttm_fixup_caching(ttm);
 465 }
 466
 467 /**
 468  * drm_ttm_bind:
 469  *
 470  * @ttm: the ttm object to bind to the graphics device
 471  *
 472  * @bo_mem: the aperture memory region which will hold the object
 473  *
 474  * Bind a ttm object to the aperture. This ensures that the necessary
 475  * pages are allocated, flushes CPU caches as needed and marks the
 476  * ttm as DRM_TTM_PAGE_USER_DIRTY to indicate that it may have been
 477  * modified by the GPU
 478  */
 479 int drm_ttm_bind(struct drm_ttm *ttm, struct drm_bo_mem_reg *bo_mem)
 480 {
 481         struct drm_bo_driver *bo_driver = ttm->dev->driver->bo_driver;
 482         int ret = 0;
 483         struct drm_ttm_backend *be;
 484
 485         if (!ttm)
 486                 return -EINVAL;
 487         if (ttm->state == ttm_bound)
 488                 return 0;
 489
 490         be = ttm->be;
 491
 492         ret = drm_ttm_populate(ttm);
 493         if (ret)
 494                 return ret;
 495
 496         if (ttm->state == ttm_unbound && !(bo_mem->flags & DRM_BO_FLAG_CACHED))
 497                 drm_ttm_set_caching(ttm, DRM_TTM_PAGE_UNCACHED);
 498         else if ((bo_mem->flags & DRM_BO_FLAG_CACHED_MAPPED) &&
 499                    bo_driver->ttm_cache_flush)
 500                 bo_driver->ttm_cache_flush(ttm);
 501
 502         ret = be->func->bind(be, bo_mem);
 503         if (ret) {
 504                 ttm->state = ttm_evicted;
 505                 DRM_ERROR("Couldn't bind backend.\n");
 506                 return ret;
 507         }
 508
 509         ttm->state = ttm_bound;
 510         if (ttm->page_flags & DRM_TTM_PAGE_USER)
 511                 ttm->page_flags |= DRM_TTM_PAGE_USER_DIRTY;
 512         return 0;
 513 }
 514 EXPORT_SYMBOL(drm_ttm_bind);