drivers/gpu/drm/i915/i915_gem_stolen.c

   1 /*
   2  * Copyright © 2008-2012 Intel Corporation
   3  *
   4  * Permission is hereby granted, free of charge, to any person obtaining a
   5  * copy of this software and associated documentation files (the "Software"),
   6  * to deal in the Software without restriction, including without limitation
   7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   8  * and/or sell copies of the Software, and to permit persons to whom the
   9  * Software is furnished to do so, subject to the following conditions:
  10  *
  11  * The above copyright notice and this permission notice (including the next
  12  * paragraph) shall be included in all copies or substantial portions of the
  13  * Software.
  14  *
  15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  18  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  19  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  20  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
  21  * IN THE SOFTWARE.
  22  *
  23  * Authors:
  24  *    Eric Anholt <eric@anholt.net>
  25  *    Chris Wilson <chris@chris-wilson.co.uk>
  26  *
  27  */
  28
  29 #include <drm/drmP.h>
  30 #include <drm/i915_drm.h>
  31 #include "i915_drv.h"
  32
  33 #define KB(x) ((x) * 1024)
  34 #define MB(x) (KB(x) * 1024)
  35
  36 /*
  37  * The BIOS typically reserves some of the system's memory for the exclusive
  38  * use of the integrated graphics. This memory is no longer available for
  39  * use by the OS and so the user finds that his system has less memory
  40  * available than he put in. We refer to this memory as stolen.
  41  *
  42  * The BIOS will allocate its framebuffer from the stolen memory. Our
  43  * goal is try to reuse that object for our own fbcon which must always
  44  * be available for panics. Anything else we can reuse the stolen memory
  45  * for is a boon.
  46  */
  47
  48 int i915_gem_stolen_insert_node_in_range(struct drm_i915_private *dev_priv,
  49                                          struct drm_mm_node *node, u64 size,
  50                                          unsigned alignment, u64 start, u64 end)
  51 {
  52         int ret;
  53
  54         if (!drm_mm_initialized(&dev_priv->mm.stolen))
  55                 return -ENODEV;
  56
  57         /* See the comment at the drm_mm_init() call for more about this check.
  58          * WaSkipStolenMemoryFirstPage:bdw,chv,kbl (incomplete)
  59          */
  60         if (start < 4096 && (IS_GEN8(dev_priv) ||
  61                              IS_KBL_REVID(dev_priv, 0, KBL_REVID_A0)))
  62                 start = 4096;
  63
  64         mutex_lock(&dev_priv->mm.stolen_lock);
  65         ret = drm_mm_insert_node_in_range(&dev_priv->mm.stolen, node, size,
  66                                           alignment, start, end,
  67                                           DRM_MM_SEARCH_DEFAULT);
  68         mutex_unlock(&dev_priv->mm.stolen_lock);
  69
  70         return ret;
  71 }
  72
  73 int i915_gem_stolen_insert_node(struct drm_i915_private *dev_priv,
  74                                 struct drm_mm_node *node, u64 size,
  75                                 unsigned alignment)
  76 {
  77         struct i915_ggtt *ggtt = &dev_priv->ggtt;
  78
  79         return i915_gem_stolen_insert_node_in_range(dev_priv, node, size,
  80                                                     alignment, 0,
  81                                                     ggtt->stolen_usable_size);
  82 }
  83
  84 void i915_gem_stolen_remove_node(struct drm_i915_private *dev_priv,
  85                                  struct drm_mm_node *node)
  86 {
  87         mutex_lock(&dev_priv->mm.stolen_lock);
  88         drm_mm_remove_node(node);
  89         mutex_unlock(&dev_priv->mm.stolen_lock);
  90 }
  91
  92 static unsigned long i915_stolen_to_physical(struct drm_device *dev)
  93 {
  94         struct drm_i915_private *dev_priv = to_i915(dev);
  95         struct pci_dev *pdev = dev_priv->drm.pdev;
  96         struct i915_ggtt *ggtt = &dev_priv->ggtt;
  97         struct resource *r;
  98         u32 base;
  99
 100         /* Almost universally we can find the Graphics Base of Stolen Memory
 101          * at register BSM (0x5c) in the igfx configuration space. On a few
 102          * (desktop) machines this is also mirrored in the bridge device at
 103          * different locations, or in the MCHBAR.
 104          *
 105          * On 865 we just check the TOUD register.
 106          *
 107          * On 830/845/85x the stolen memory base isn't available in any
 108          * register. We need to calculate it as TOM-TSEG_SIZE-stolen_size.
 109          *
 110          */
 111         base = 0;
 112         if (INTEL_INFO(dev)->gen >= 3) {
 113                 u32 bsm;
 114
 115                 pci_read_config_dword(pdev, INTEL_BSM, &bsm);
 116
 117                 base = bsm & INTEL_BSM_MASK;
 118         } else if (IS_I865G(dev)) {
 119                 u32 tseg_size = 0;
 120                 u16 toud = 0;
 121                 u8 tmp;
 122
 123                 pci_bus_read_config_byte(pdev->bus, PCI_DEVFN(0, 0),
 124                                          I845_ESMRAMC, &tmp);
 125
 126                 if (tmp & TSEG_ENABLE) {
 127                         switch (tmp & I845_TSEG_SIZE_MASK) {
 128                         case I845_TSEG_SIZE_512K:
 129                                 tseg_size = KB(512);
 130                                 break;
 131                         case I845_TSEG_SIZE_1M:
 132                                 tseg_size = MB(1);
 133                                 break;
 134                         }
 135                 }
 136
 137                 pci_bus_read_config_word(pdev->bus, PCI_DEVFN(0, 0),
 138                                          I865_TOUD, &toud);
 139
 140                 base = (toud << 16) + tseg_size;
 141         } else if (IS_I85X(dev)) {
 142                 u32 tseg_size = 0;
 143                 u32 tom;
 144                 u8 tmp;
 145
 146                 pci_bus_read_config_byte(pdev->bus, PCI_DEVFN(0, 0),
 147                                          I85X_ESMRAMC, &tmp);
 148
 149                 if (tmp & TSEG_ENABLE)
 150                         tseg_size = MB(1);
 151
 152                 pci_bus_read_config_byte(pdev->bus, PCI_DEVFN(0, 1),
 153                                          I85X_DRB3, &tmp);
 154                 tom = tmp * MB(32);
 155
 156                 base = tom - tseg_size - ggtt->stolen_size;
 157         } else if (IS_845G(dev)) {
 158                 u32 tseg_size = 0;
 159                 u32 tom;
 160                 u8 tmp;
 161
 162                 pci_bus_read_config_byte(pdev->bus, PCI_DEVFN(0, 0),
 163                                          I845_ESMRAMC, &tmp);
 164
 165                 if (tmp & TSEG_ENABLE) {
 166                         switch (tmp & I845_TSEG_SIZE_MASK) {
 167                         case I845_TSEG_SIZE_512K:
 168                                 tseg_size = KB(512);
 169                                 break;
 170                         case I845_TSEG_SIZE_1M:
 171                                 tseg_size = MB(1);
 172                                 break;
 173                         }
 174                 }
 175
 176                 pci_bus_read_config_byte(pdev->bus, PCI_DEVFN(0, 0),
 177                                          I830_DRB3, &tmp);
 178                 tom = tmp * MB(32);
 179
 180                 base = tom - tseg_size - ggtt->stolen_size;
 181         } else if (IS_I830(dev)) {
 182                 u32 tseg_size = 0;
 183                 u32 tom;
 184                 u8 tmp;
 185
 186                 pci_bus_read_config_byte(pdev->bus, PCI_DEVFN(0, 0),
 187                                          I830_ESMRAMC, &tmp);
 188
 189                 if (tmp & TSEG_ENABLE) {
 190                         if (tmp & I830_TSEG_SIZE_1M)
 191                                 tseg_size = MB(1);
 192                         else
 193                                 tseg_size = KB(512);
 194                 }
 195
 196                 pci_bus_read_config_byte(pdev->bus, PCI_DEVFN(0, 0),
 197                                          I830_DRB3, &tmp);
 198                 tom = tmp * MB(32);
 199
 200                 base = tom - tseg_size - ggtt->stolen_size;
 201         }
 202
 203         if (base == 0)
 204                 return 0;
 205
 206         /* make sure we don't clobber the GTT if it's within stolen memory */
 207         if (INTEL_INFO(dev)->gen <= 4 && !IS_G33(dev) && !IS_G4X(dev)) {
 208                 struct {
 209                         u32 start, end;
 210                 } stolen[2] = {
 211                         { .start = base, .end = base + ggtt->stolen_size, },
 212                         { .start = base, .end = base + ggtt->stolen_size, },
 213                 };
 214                 u64 ggtt_start, ggtt_end;
 215
 216                 ggtt_start = I915_READ(PGTBL_CTL);
 217                 if (IS_GEN4(dev))
 218                         ggtt_start = (ggtt_start & PGTBL_ADDRESS_LO_MASK) |
 219                                      (ggtt_start & PGTBL_ADDRESS_HI_MASK) << 28;
 220                 else
 221                         ggtt_start &= PGTBL_ADDRESS_LO_MASK;
 222                 ggtt_end = ggtt_start + ggtt_total_entries(ggtt) * 4;
 223
 224                 if (ggtt_start >= stolen[0].start && ggtt_start < stolen[0].end)
 225                         stolen[0].end = ggtt_start;
 226                 if (ggtt_end > stolen[1].start && ggtt_end <= stolen[1].end)
 227                         stolen[1].start = ggtt_end;
 228
 229                 /* pick the larger of the two chunks */
 230                 if (stolen[0].end - stolen[0].start >
 231                     stolen[1].end - stolen[1].start) {
 232                         base = stolen[0].start;
 233                         ggtt->stolen_size = stolen[0].end - stolen[0].start;
 234                 } else {
 235                         base = stolen[1].start;
 236                         ggtt->stolen_size = stolen[1].end - stolen[1].start;
 237                 }
 238
 239                 if (stolen[0].start != stolen[1].start ||
 240                     stolen[0].end != stolen[1].end) {
 241                         DRM_DEBUG_KMS("GTT within stolen memory at 0x%llx-0x%llx\n",
 242                                       (unsigned long long)ggtt_start,
 243                                       (unsigned long long)ggtt_end - 1);
 244                         DRM_DEBUG_KMS("Stolen memory adjusted to 0x%x-0x%x\n",
 245                                       base, base + (u32)ggtt->stolen_size - 1);
 246                 }
 247         }
 248
 249
 250         /* Verify that nothing else uses this physical address. Stolen
 251          * memory should be reserved by the BIOS and hidden from the
 252          * kernel. So if the region is already marked as busy, something
 253          * is seriously wrong.
 254          */
 255         r = devm_request_mem_region(dev->dev, base, ggtt->stolen_size,
 256                                     "Graphics Stolen Memory");
 257         if (r == NULL) {
 258                 /*
 259                  * One more attempt but this time requesting region from
 260                  * base + 1, as we have seen that this resolves the region
 261                  * conflict with the PCI Bus.
 262                  * This is a BIOS w/a: Some BIOS wrap stolen in the root
 263                  * PCI bus, but have an off-by-one error. Hence retry the
 264                  * reservation starting from 1 instead of 0.
 265                  */
 266                 r = devm_request_mem_region(dev->dev, base + 1,
 267                                             ggtt->stolen_size - 1,
 268                                             "Graphics Stolen Memory");
 269                 /*
 270                  * GEN3 firmware likes to smash pci bridges into the stolen
 271                  * range. Apparently this works.
 272                  */
 273                 if (r == NULL && !IS_GEN3(dev)) {
 274                         DRM_ERROR("conflict detected with stolen region: [0x%08x - 0x%08x]\n",
 275                                   base, base + (uint32_t)ggtt->stolen_size);
 276                         base = 0;
 277                 }
 278         }
 279
 280         return base;
 281 }
 282
 283 void i915_gem_cleanup_stolen(struct drm_device *dev)
 284 {
 285         struct drm_i915_private *dev_priv = to_i915(dev);
 286
 287         if (!drm_mm_initialized(&dev_priv->mm.stolen))
 288                 return;
 289
 290         drm_mm_takedown(&dev_priv->mm.stolen);
 291 }
 292
 293 static void g4x_get_stolen_reserved(struct drm_i915_private *dev_priv,
 294                                     unsigned long *base, unsigned long *size)
 295 {
 296         struct i915_ggtt *ggtt = &dev_priv->ggtt;
 297         uint32_t reg_val = I915_READ(IS_GM45(dev_priv) ?
 298                                      CTG_STOLEN_RESERVED :
 299                                      ELK_STOLEN_RESERVED);
 300         unsigned long stolen_top = dev_priv->mm.stolen_base +
 301                                    ggtt->stolen_size;
 302
 303         *base = (reg_val & G4X_STOLEN_RESERVED_ADDR2_MASK) << 16;
 304
 305         WARN_ON((reg_val & G4X_STOLEN_RESERVED_ADDR1_MASK) < *base);
 306
 307         /* On these platforms, the register doesn't have a size field, so the
 308          * size is the distance between the base and the top of the stolen
 309          * memory. We also have the genuine case where base is zero and there's
 310          * nothing reserved. */
 311         if (*base == 0)
 312                 *size = 0;
 313         else
 314                 *size = stolen_top - *base;
 315 }
 316
 317 static void gen6_get_stolen_reserved(struct drm_i915_private *dev_priv,
 318                                      unsigned long *base, unsigned long *size)
 319 {
 320         uint32_t reg_val = I915_READ(GEN6_STOLEN_RESERVED);
 321
 322         *base = reg_val & GEN6_STOLEN_RESERVED_ADDR_MASK;
 323
 324         switch (reg_val & GEN6_STOLEN_RESERVED_SIZE_MASK) {
 325         case GEN6_STOLEN_RESERVED_1M:
 326                 *size = 1024 * 1024;
 327                 break;
 328         case GEN6_STOLEN_RESERVED_512K:
 329                 *size = 512 * 1024;
 330                 break;
 331         case GEN6_STOLEN_RESERVED_256K:
 332                 *size = 256 * 1024;
 333                 break;
 334         case GEN6_STOLEN_RESERVED_128K:
 335                 *size = 128 * 1024;
 336                 break;
 337         default:
 338                 *size = 1024 * 1024;
 339                 MISSING_CASE(reg_val & GEN6_STOLEN_RESERVED_SIZE_MASK);
 340         }
 341 }
 342
 343 static void gen7_get_stolen_reserved(struct drm_i915_private *dev_priv,
 344                                      unsigned long *base, unsigned long *size)
 345 {
 346         uint32_t reg_val = I915_READ(GEN6_STOLEN_RESERVED);
 347
 348         *base = reg_val & GEN7_STOLEN_RESERVED_ADDR_MASK;
 349
 350         switch (reg_val & GEN7_STOLEN_RESERVED_SIZE_MASK) {
 351         case GEN7_STOLEN_RESERVED_1M:
 352                 *size = 1024 * 1024;
 353                 break;
 354         case GEN7_STOLEN_RESERVED_256K:
 355                 *size = 256 * 1024;
 356                 break;
 357         default:
 358                 *size = 1024 * 1024;
 359                 MISSING_CASE(reg_val & GEN7_STOLEN_RESERVED_SIZE_MASK);
 360         }
 361 }
 362
 363 static void gen8_get_stolen_reserved(struct drm_i915_private *dev_priv,
 364                                      unsigned long *base, unsigned long *size)
 365 {
 366         uint32_t reg_val = I915_READ(GEN6_STOLEN_RESERVED);
 367
 368         *base = reg_val & GEN6_STOLEN_RESERVED_ADDR_MASK;
 369
 370         switch (reg_val & GEN8_STOLEN_RESERVED_SIZE_MASK) {
 371         case GEN8_STOLEN_RESERVED_1M:
 372                 *size = 1024 * 1024;
 373                 break;
 374         case GEN8_STOLEN_RESERVED_2M:
 375                 *size = 2 * 1024 * 1024;
 376                 break;
 377         case GEN8_STOLEN_RESERVED_4M:
 378                 *size = 4 * 1024 * 1024;
 379                 break;
 380         case GEN8_STOLEN_RESERVED_8M:
 381                 *size = 8 * 1024 * 1024;
 382                 break;
 383         default:
 384                 *size = 8 * 1024 * 1024;
 385                 MISSING_CASE(reg_val & GEN8_STOLEN_RESERVED_SIZE_MASK);
 386         }
 387 }
 388
 389 static void bdw_get_stolen_reserved(struct drm_i915_private *dev_priv,
 390                                     unsigned long *base, unsigned long *size)
 391 {
 392         struct i915_ggtt *ggtt = &dev_priv->ggtt;
 393         uint32_t reg_val = I915_READ(GEN6_STOLEN_RESERVED);
 394         unsigned long stolen_top;
 395
 396         stolen_top = dev_priv->mm.stolen_base + ggtt->stolen_size;
 397
 398         *base = reg_val & GEN6_STOLEN_RESERVED_ADDR_MASK;
 399
 400         /* On these platforms, the register doesn't have a size field, so the
 401          * size is the distance between the base and the top of the stolen
 402          * memory. We also have the genuine case where base is zero and there's
 403          * nothing reserved. */
 404         if (*base == 0)
 405                 *size = 0;
 406         else
 407                 *size = stolen_top - *base;
 408 }
 409
 410 int i915_gem_init_stolen(struct drm_device *dev)
 411 {
 412         struct drm_i915_private *dev_priv = to_i915(dev);
 413         struct i915_ggtt *ggtt = &dev_priv->ggtt;
 414         unsigned long reserved_total, reserved_base = 0, reserved_size;
 415         unsigned long stolen_top;
 416
 417         mutex_init(&dev_priv->mm.stolen_lock);
 418
 419 #ifdef CONFIG_INTEL_IOMMU
 420         if (intel_iommu_gfx_mapped && INTEL_INFO(dev)->gen < 8) {
 421                 DRM_INFO("DMAR active, disabling use of stolen memory\n");
 422                 return 0;
 423         }
 424 #endif
 425
 426         if (ggtt->stolen_size == 0)
 427                 return 0;
 428
 429         dev_priv->mm.stolen_base = i915_stolen_to_physical(dev);
 430         if (dev_priv->mm.stolen_base == 0)
 431                 return 0;
 432
 433         stolen_top = dev_priv->mm.stolen_base + ggtt->stolen_size;
 434
 435         switch (INTEL_INFO(dev_priv)->gen) {
 436         case 2:
 437         case 3:
 438                 break;
 439         case 4:
 440                 if (IS_G4X(dev))
 441                         g4x_get_stolen_reserved(dev_priv, &reserved_base,
 442                                                 &reserved_size);
 443                 break;
 444         case 5:
 445                 /* Assume the gen6 maximum for the older platforms. */
 446                 reserved_size = 1024 * 1024;
 447                 reserved_base = stolen_top - reserved_size;
 448                 break;
 449         case 6:
 450                 gen6_get_stolen_reserved(dev_priv, &reserved_base,
 451                                          &reserved_size);
 452                 break;
 453         case 7:
 454                 gen7_get_stolen_reserved(dev_priv, &reserved_base,
 455                                          &reserved_size);
 456                 break;
 457         default:
 458                 if (IS_BROADWELL(dev_priv) ||
 459                     IS_SKYLAKE(dev_priv) || IS_KABYLAKE(dev))
 460                         bdw_get_stolen_reserved(dev_priv, &reserved_base,
 461                                                 &reserved_size);
 462                 else
 463                         gen8_get_stolen_reserved(dev_priv, &reserved_base,
 464                                                  &reserved_size);
 465                 break;
 466         }
 467
 468         /* It is possible for the reserved base to be zero, but the register
 469          * field for size doesn't have a zero option. */
 470         if (reserved_base == 0) {
 471                 reserved_size = 0;
 472                 reserved_base = stolen_top;
 473         }
 474
 475         if (reserved_base < dev_priv->mm.stolen_base ||
 476             reserved_base + reserved_size > stolen_top) {
 477                 DRM_DEBUG_KMS("Stolen reserved area [0x%08lx - 0x%08lx] outside stolen memory [0x%08lx - 0x%08lx]\n",
 478                               reserved_base, reserved_base + reserved_size,
 479                               dev_priv->mm.stolen_base, stolen_top);
 480                 return 0;
 481         }
 482
 483         ggtt->stolen_reserved_base = reserved_base;
 484         ggtt->stolen_reserved_size = reserved_size;
 485
 486         /* It is possible for the reserved area to end before the end of stolen
 487          * memory, so just consider the start. */
 488         reserved_total = stolen_top - reserved_base;
 489
 490         DRM_DEBUG_KMS("Memory reserved for graphics device: %zuK, usable: %luK\n",
 491                       ggtt->stolen_size >> 10,
 492                       (ggtt->stolen_size - reserved_total) >> 10);
 493
 494         ggtt->stolen_usable_size = ggtt->stolen_size - reserved_total;
 495
 496         /*
 497          * Basic memrange allocator for stolen space.
 498          *
 499          * TODO: Notice that some platforms require us to not use the first page
 500          * of the stolen memory but their BIOSes may still put the framebuffer
 501          * on the first page. So we don't reserve this page for now because of
 502          * that. Our current solution is to just prevent new nodes from being
 503          * inserted on the first page - see the check we have at
 504          * i915_gem_stolen_insert_node_in_range(). We may want to fix the fbcon
 505          * problem later.
 506          */
 507         drm_mm_init(&dev_priv->mm.stolen, 0, ggtt->stolen_usable_size);
 508
 509         return 0;
 510 }
 511
 512 static struct sg_table *
 513 i915_pages_create_for_stolen(struct drm_device *dev,
 514                              u32 offset, u32 size)
 515 {
 516         struct drm_i915_private *dev_priv = to_i915(dev);
 517         struct i915_ggtt *ggtt = &dev_priv->ggtt;
 518         struct sg_table *st;
 519         struct scatterlist *sg;
 520
 521         DRM_DEBUG_DRIVER("offset=0x%x, size=%d\n", offset, size);
 522         BUG_ON(offset > ggtt->stolen_size - size);
 523
 524         /* We hide that we have no struct page backing our stolen object
 525          * by wrapping the contiguous physical allocation with a fake
 526          * dma mapping in a single scatterlist.
 527          */
 528
 529         st = kmalloc(sizeof(*st), GFP_KERNEL);
 530         if (st == NULL)
 531                 return NULL;
 532
 533         if (sg_alloc_table(st, 1, GFP_KERNEL)) {
 534                 kfree(st);
 535                 return NULL;
 536         }
 537
 538         sg = st->sgl;
 539         sg->offset = 0;
 540         sg->length = size;
 541
 542         sg_dma_address(sg) = (dma_addr_t)dev_priv->mm.stolen_base + offset;
 543         sg_dma_len(sg) = size;
 544
 545         return st;
 546 }
 547
 548 static int i915_gem_object_get_pages_stolen(struct drm_i915_gem_object *obj)
 549 {
 550         BUG();
 551         return -EINVAL;
 552 }
 553
 554 static void i915_gem_object_put_pages_stolen(struct drm_i915_gem_object *obj)
 555 {
 556         /* Should only be called during free */
 557         sg_free_table(obj->pages);
 558         kfree(obj->pages);
 559 }
 560
 561
 562 static void
 563 i915_gem_object_release_stolen(struct drm_i915_gem_object *obj)
 564 {
 565         struct drm_i915_private *dev_priv = to_i915(obj->base.dev);
 566
 567         if (obj->stolen) {
 568                 i915_gem_stolen_remove_node(dev_priv, obj->stolen);
 569                 kfree(obj->stolen);
 570                 obj->stolen = NULL;
 571         }
 572 }
 573 static const struct drm_i915_gem_object_ops i915_gem_object_stolen_ops = {
 574         .get_pages = i915_gem_object_get_pages_stolen,
 575         .put_pages = i915_gem_object_put_pages_stolen,
 576         .release = i915_gem_object_release_stolen,
 577 };
 578
 579 static struct drm_i915_gem_object *
 580 _i915_gem_object_create_stolen(struct drm_device *dev,
 581                                struct drm_mm_node *stolen)
 582 {
 583         struct drm_i915_gem_object *obj;
 584
 585         obj = i915_gem_object_alloc(dev);
 586         if (obj == NULL)
 587                 return NULL;
 588
 589         drm_gem_private_object_init(dev, &obj->base, stolen->size);
 590         i915_gem_object_init(obj, &i915_gem_object_stolen_ops);
 591
 592         obj->pages = i915_pages_create_for_stolen(dev,
 593                                                   stolen->start, stolen->size);
 594         if (obj->pages == NULL)
 595                 goto cleanup;
 596
 597         obj->get_page.sg = obj->pages->sgl;
 598         obj->get_page.last = 0;
 599
 600         i915_gem_object_pin_pages(obj);
 601         obj->stolen = stolen;
 602
 603         obj->base.read_domains = I915_GEM_DOMAIN_CPU | I915_GEM_DOMAIN_GTT;
 604         obj->cache_level = HAS_LLC(dev) ? I915_CACHE_LLC : I915_CACHE_NONE;
 605
 606         return obj;
 607
 608 cleanup:
 609         i915_gem_object_free(obj);
 610         return NULL;
 611 }
 612
 613 struct drm_i915_gem_object *
 614 i915_gem_object_create_stolen(struct drm_device *dev, u32 size)
 615 {
 616         struct drm_i915_private *dev_priv = to_i915(dev);
 617         struct drm_i915_gem_object *obj;
 618         struct drm_mm_node *stolen;
 619         int ret;
 620
 621         if (!drm_mm_initialized(&dev_priv->mm.stolen))
 622                 return NULL;
 623
 624         DRM_DEBUG_KMS("creating stolen object: size=%x\n", size);
 625         if (size == 0)
 626                 return NULL;
 627
 628         stolen = kzalloc(sizeof(*stolen), GFP_KERNEL);
 629         if (!stolen)
 630                 return NULL;
 631
 632         ret = i915_gem_stolen_insert_node(dev_priv, stolen, size, 4096);
 633         if (ret) {
 634                 kfree(stolen);
 635                 return NULL;
 636         }
 637
 638         obj = _i915_gem_object_create_stolen(dev, stolen);
 639         if (obj)
 640                 return obj;
 641
 642         i915_gem_stolen_remove_node(dev_priv, stolen);
 643         kfree(stolen);
 644         return NULL;
 645 }
 646
 647 struct drm_i915_gem_object *
 648 i915_gem_object_create_stolen_for_preallocated(struct drm_device *dev,
 649                                                u32 stolen_offset,
 650                                                u32 gtt_offset,
 651                                                u32 size)
 652 {
 653         struct drm_i915_private *dev_priv = to_i915(dev);
 654         struct i915_ggtt *ggtt = &dev_priv->ggtt;
 655         struct drm_i915_gem_object *obj;
 656         struct drm_mm_node *stolen;
 657         struct i915_vma *vma;
 658         int ret;
 659
 660         if (!drm_mm_initialized(&dev_priv->mm.stolen))
 661                 return NULL;
 662
 663         lockdep_assert_held(&dev->struct_mutex);
 664
 665         DRM_DEBUG_KMS("creating preallocated stolen object: stolen_offset=%x, gtt_offset=%x, size=%x\n",
 666                         stolen_offset, gtt_offset, size);
 667
 668         /* KISS and expect everything to be page-aligned */
 669         if (WARN_ON(size == 0) || WARN_ON(size & 4095) ||
 670             WARN_ON(stolen_offset & 4095))
 671                 return NULL;
 672
 673         stolen = kzalloc(sizeof(*stolen), GFP_KERNEL);
 674         if (!stolen)
 675                 return NULL;
 676
 677         stolen->start = stolen_offset;
 678         stolen->size = size;
 679         mutex_lock(&dev_priv->mm.stolen_lock);
 680         ret = drm_mm_reserve_node(&dev_priv->mm.stolen, stolen);
 681         mutex_unlock(&dev_priv->mm.stolen_lock);
 682         if (ret) {
 683                 DRM_DEBUG_KMS("failed to allocate stolen space\n");
 684                 kfree(stolen);
 685                 return NULL;
 686         }
 687
 688         obj = _i915_gem_object_create_stolen(dev, stolen);
 689         if (obj == NULL) {
 690                 DRM_DEBUG_KMS("failed to allocate stolen object\n");
 691                 i915_gem_stolen_remove_node(dev_priv, stolen);
 692                 kfree(stolen);
 693                 return NULL;
 694         }
 695
 696         /* Some objects just need physical mem from stolen space */
 697         if (gtt_offset == I915_GTT_OFFSET_NONE)
 698                 return obj;
 699
 700         vma = i915_gem_obj_lookup_or_create_vma(obj, &ggtt->base, NULL);
 701         if (IS_ERR(vma)) {
 702                 ret = PTR_ERR(vma);
 703                 goto err;
 704         }
 705
 706         /* To simplify the initialisation sequence between KMS and GTT,
 707          * we allow construction of the stolen object prior to
 708          * setting up the GTT space. The actual reservation will occur
 709          * later.
 710          */
 711         vma->node.start = gtt_offset;
 712         vma->node.size = size;
 713
 714         ret = drm_mm_reserve_node(&ggtt->base.mm, &vma->node);
 715         if (ret) {
 716                 DRM_DEBUG_KMS("failed to allocate stolen GTT space\n");
 717                 goto err;
 718         }
 719
 720         vma->pages = obj->pages;
 721         vma->flags |= I915_VMA_GLOBAL_BIND;
 722         __i915_vma_set_map_and_fenceable(vma);
 723         list_move_tail(&vma->vm_link, &ggtt->base.inactive_list);
 724         obj->bind_count++;
 725
 726         list_add_tail(&obj->global_list, &dev_priv->mm.bound_list);
 727         i915_gem_object_pin_pages(obj);
 728
 729         return obj;
 730
 731 err:
 732         i915_gem_object_put(obj);
 733         return NULL;
 734 }