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