sys/dev/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 /*
  34  * The BIOS typically reserves some of the system's memory for the exclusive
  35  * use of the integrated graphics. This memory is no longer available for
  36  * use by the OS and so the user finds that his system has less memory
  37  * available than he put in. We refer to this memory as stolen.
  38  *
  39  * The BIOS will allocate its framebuffer from the stolen memory. Our
  40  * goal is try to reuse that object for our own fbcon which must always
  41  * be available for panics. Anything else we can reuse the stolen memory
  42  * for is a boon.
  43  */
  44
  45 static unsigned long i915_stolen_to_physical(struct drm_device *dev)
  46 {
  47         struct drm_i915_private *dev_priv = dev->dev_private;
  48         u32 base;
  49
  50         /* Almost universally we can find the Graphics Base of Stolen Memory
  51          * at offset 0x5c in the igfx configuration space. On a few (desktop)
  52          * machines this is also mirrored in the bridge device at different
  53          * locations, or in the MCHBAR. On gen2, the layout is again slightly
  54          * different with the Graphics Segment immediately following Top of
  55          * Memory (or Top of Usable DRAM). Note it appears that TOUD is only
  56          * reported by 865g, so we just use the top of memory as determined
  57          * by the e820 probe.
  58          *
  59          * XXX However gen2 requires an unavailable symbol.
  60          */
  61         base = 0;
  62         if (INTEL_INFO(dev)->gen >= 3) {
  63                 /* Read Graphics Base of Stolen Memory directly */
  64                 pci_read_config_dword(dev->pdev, 0x5c, &base);
  65                 base &= ~((1<<20) - 1);
  66         } else { /* GEN2 */
  67 #if 0
  68                 /* Stolen is immediately above Top of Memory */
  69                 base = max_low_pfn_mapped << PAGE_SHIFT;
  70 #endif
  71         }
  72
  73         if (base == 0)
  74                 return 0;
  75
  76         /* make sure we don't clobber the GTT if it's within stolen memory */
  77         if (INTEL_INFO(dev)->gen <= 4 && !IS_G33(dev) && !IS_G4X(dev)) {
  78                 struct {
  79                         u32 start, end;
  80                 } stolen[2] = {
  81                         { .start = base, .end = base + dev_priv->gtt.stolen_size, },
  82                         { .start = base, .end = base + dev_priv->gtt.stolen_size, },
  83                 };
  84                 u64 gtt_start, gtt_end;
  85
  86                 gtt_start = I915_READ(PGTBL_CTL);
  87                 if (IS_GEN4(dev))
  88                         gtt_start = (gtt_start & PGTBL_ADDRESS_LO_MASK) |
  89                                 (gtt_start & PGTBL_ADDRESS_HI_MASK) << 28;
  90                 else
  91                         gtt_start &= PGTBL_ADDRESS_LO_MASK;
  92                 gtt_end = gtt_start + gtt_total_entries(dev_priv->gtt) * 4;
  93
  94                 if (gtt_start >= stolen[0].start && gtt_start < stolen[0].end)
  95                         stolen[0].end = gtt_start;
  96                 if (gtt_end > stolen[1].start && gtt_end <= stolen[1].end)
  97                         stolen[1].start = gtt_end;
  98
  99                 /* pick the larger of the two chunks */
 100                 if (stolen[0].end - stolen[0].start >
 101                     stolen[1].end - stolen[1].start) {
 102                         base = stolen[0].start;
 103                         dev_priv->gtt.stolen_size = stolen[0].end - stolen[0].start;
 104                 } else {
 105                         base = stolen[1].start;
 106                         dev_priv->gtt.stolen_size = stolen[1].end - stolen[1].start;
 107                 }
 108
 109                 if (stolen[0].start != stolen[1].start ||
 110                     stolen[0].end != stolen[1].end) {
 111                         DRM_DEBUG_KMS("GTT within stolen memory at 0x%llx-0x%llx\n",
 112                                       (unsigned long long) gtt_start,
 113                                       (unsigned long long) gtt_end - 1);
 114                         DRM_DEBUG_KMS("Stolen memory adjusted to 0x%x-0x%x\n",
 115                                       base, base + (u32) dev_priv->gtt.stolen_size - 1);
 116                 }
 117         }
 118
 119
 120         /* Verify that nothing else uses this physical address. Stolen
 121          * memory should be reserved by the BIOS and hidden from the
 122          * kernel. So if the region is already marked as busy, something
 123          * is seriously wrong.
 124          */
 125 #if 0
 126         r = devm_request_mem_region(dev->dev, base, dev_priv->gtt.stolen_size,
 127                                     "Graphics Stolen Memory");
 128         if (r == NULL) {
 129                 /*
 130                  * One more attempt but this time requesting region from
 131                  * base + 1, as we have seen that this resolves the region
 132                  * conflict with the PCI Bus.
 133                  * This is a BIOS w/a: Some BIOS wrap stolen in the root
 134                  * PCI bus, but have an off-by-one error. Hence retry the
 135                  * reservation starting from 1 instead of 0.
 136                  */
 137                 r = devm_request_mem_region(dev->dev, base + 1,
 138                                             dev_priv->gtt.stolen_size - 1,
 139                                             "Graphics Stolen Memory");
 140                 if (r == NULL) {
 141                         DRM_ERROR("conflict detected with stolen region: [0x%08x - 0x%08x]\n",
 142                                   base, base + (uint32_t)dev_priv->gtt.stolen_size);
 143                         base = 0;
 144                 }
 145         }
 146 #endif
 147
 148         return base;
 149 }
 150
 151 static int find_compression_threshold(struct drm_device *dev,
 152                                       struct drm_mm_node *node,
 153                                       int size,
 154                                       int fb_cpp)
 155 {
 156         struct drm_i915_private *dev_priv = dev->dev_private;
 157         int compression_threshold = 1;
 158         int ret;
 159
 160         /* HACK: This code depends on what we will do in *_enable_fbc. If that
 161          * code changes, this code needs to change as well.
 162          *
 163          * The enable_fbc code will attempt to use one of our 2 compression
 164          * thresholds, therefore, in that case, we only have 1 resort.
 165          */
 166
 167         /* Try to over-allocate to reduce reallocations and fragmentation. */
 168         ret = drm_mm_insert_node(&dev_priv->mm.stolen, node,
 169                                  size <<= 1, 4096, DRM_MM_SEARCH_DEFAULT);
 170         if (ret == 0)
 171                 return compression_threshold;
 172
 173 again:
 174         /* HW's ability to limit the CFB is 1:4 */
 175         if (compression_threshold > 4 ||
 176             (fb_cpp == 2 && compression_threshold == 2))
 177                 return 0;
 178
 179         ret = drm_mm_insert_node(&dev_priv->mm.stolen, node,
 180                                  size >>= 1, 4096,
 181                                  DRM_MM_SEARCH_DEFAULT);
 182         if (ret && INTEL_INFO(dev)->gen <= 4) {
 183                 return 0;
 184         } else if (ret) {
 185                 compression_threshold <<= 1;
 186                 goto again;
 187         } else {
 188                 return compression_threshold;
 189         }
 190 }
 191
 192 static int i915_setup_compression(struct drm_device *dev, int size, int fb_cpp)
 193 {
 194         struct drm_i915_private *dev_priv = dev->dev_private;
 195         struct drm_mm_node *compressed_llb;
 196         int ret;
 197
 198         ret = find_compression_threshold(dev, &dev_priv->fbc.compressed_fb,
 199                                          size, fb_cpp);
 200         if (!ret)
 201                 goto err_llb;
 202         else if (ret > 1) {
 203                 DRM_INFO("Reducing the compressed framebuffer size. This may lead to less power savings than a non-reduced-size. Try to increase stolen memory size if available in BIOS.\n");
 204
 205         }
 206
 207         dev_priv->fbc.threshold = ret;
 208
 209         if (HAS_PCH_SPLIT(dev))
 210                 I915_WRITE(ILK_DPFC_CB_BASE, dev_priv->fbc.compressed_fb.start);
 211         else if (IS_GM45(dev)) {
 212                 I915_WRITE(DPFC_CB_BASE, dev_priv->fbc.compressed_fb.start);
 213         } else {
 214                 compressed_llb = kzalloc(sizeof(*compressed_llb), GFP_KERNEL);
 215                 if (!compressed_llb)
 216                         goto err_fb;
 217
 218                 ret = drm_mm_insert_node(&dev_priv->mm.stolen, compressed_llb,
 219                                          4096, 4096, DRM_MM_SEARCH_DEFAULT);
 220                 if (ret)
 221                         goto err_fb;
 222
 223                 dev_priv->fbc.compressed_llb = compressed_llb;
 224
 225                 I915_WRITE(FBC_CFB_BASE,
 226                            dev_priv->mm.stolen_base + dev_priv->fbc.compressed_fb.start);
 227                 I915_WRITE(FBC_LL_BASE,
 228                            dev_priv->mm.stolen_base + compressed_llb->start);
 229         }
 230
 231         dev_priv->fbc.size = size / dev_priv->fbc.threshold;
 232
 233         DRM_DEBUG_KMS("reserved %d bytes of contiguous stolen space for FBC\n",
 234                       size);
 235
 236         return 0;
 237
 238 err_fb:
 239         kfree(compressed_llb);
 240         drm_mm_remove_node(&dev_priv->fbc.compressed_fb);
 241 err_llb:
 242         pr_info_once("drm: not enough stolen space for compressed buffer (need %d more bytes), disabling. Hint: you may be able to increase stolen memory size in the BIOS to avoid this.\n", size);
 243         return -ENOSPC;
 244 }
 245
 246 int i915_gem_stolen_setup_compression(struct drm_device *dev, int size, int fb_cpp)
 247 {
 248         struct drm_i915_private *dev_priv = dev->dev_private;
 249
 250         if (!drm_mm_initialized(&dev_priv->mm.stolen))
 251                 return -ENODEV;
 252
 253         if (size < dev_priv->fbc.size)
 254                 return 0;
 255
 256         /* Release any current block */
 257         i915_gem_stolen_cleanup_compression(dev);
 258
 259         return i915_setup_compression(dev, size, fb_cpp);
 260 }
 261
 262 void i915_gem_stolen_cleanup_compression(struct drm_device *dev)
 263 {
 264         struct drm_i915_private *dev_priv = dev->dev_private;
 265
 266         if (dev_priv->fbc.size == 0)
 267                 return;
 268
 269         drm_mm_remove_node(&dev_priv->fbc.compressed_fb);
 270
 271         if (dev_priv->fbc.compressed_llb) {
 272                 drm_mm_remove_node(dev_priv->fbc.compressed_llb);
 273                 kfree(dev_priv->fbc.compressed_llb);
 274         }
 275
 276         dev_priv->fbc.size = 0;
 277 }
 278
 279 void i915_gem_cleanup_stolen(struct drm_device *dev)
 280 {
 281         struct drm_i915_private *dev_priv = dev->dev_private;
 282
 283         if (!drm_mm_initialized(&dev_priv->mm.stolen))
 284                 return;
 285
 286         i915_gem_stolen_cleanup_compression(dev);
 287         drm_mm_takedown(&dev_priv->mm.stolen);
 288 }
 289
 290 int i915_gem_init_stolen(struct drm_device *dev)
 291 {
 292         struct drm_i915_private *dev_priv = dev->dev_private;
 293         int bios_reserved = 0;
 294
 295 #ifdef CONFIG_INTEL_IOMMU
 296         if (intel_iommu_gfx_mapped && INTEL_INFO(dev)->gen < 8) {
 297                 DRM_INFO("DMAR active, disabling use of stolen memory\n");
 298                 return 0;
 299         }
 300 #endif
 301
 302         if (dev_priv->gtt.stolen_size == 0)
 303                 return 0;
 304
 305         dev_priv->mm.stolen_base = i915_stolen_to_physical(dev);
 306         if (dev_priv->mm.stolen_base == 0)
 307                 return 0;
 308
 309         DRM_DEBUG_KMS("found %zd bytes of stolen memory at %08lx\n",
 310                       dev_priv->gtt.stolen_size, dev_priv->mm.stolen_base);
 311
 312         if (IS_VALLEYVIEW(dev))
 313                 bios_reserved = 1024*1024; /* top 1M on VLV/BYT */
 314
 315         if (WARN_ON(bios_reserved > dev_priv->gtt.stolen_size))
 316                 return 0;
 317
 318         /* Basic memrange allocator for stolen space */
 319         drm_mm_init(&dev_priv->mm.stolen, 0, dev_priv->gtt.stolen_size -
 320                     bios_reserved);
 321
 322         return 0;
 323 }
 324
 325 #if 0
 326 static struct sg_table *
 327 i915_pages_create_for_stolen(struct drm_device *dev,
 328                              u32 offset, u32 size)
 329 {
 330         struct drm_i915_private *dev_priv = dev->dev_private;
 331         struct sg_table *st;
 332         struct scatterlist *sg;
 333
 334         DRM_DEBUG_DRIVER("offset=0x%x, size=%d\n", offset, size);
 335         BUG_ON(offset > dev_priv->gtt.stolen_size - size);
 336
 337         /* We hide that we have no struct page backing our stolen object
 338          * by wrapping the contiguous physical allocation with a fake
 339          * dma mapping in a single scatterlist.
 340          */
 341
 342         st = kmalloc(sizeof(*st), GFP_KERNEL);
 343         if (st == NULL)
 344                 return NULL;
 345
 346         if (sg_alloc_table(st, 1, GFP_KERNEL)) {
 347                 kfree(st);
 348                 return NULL;
 349         }
 350
 351         sg = st->sgl;
 352         sg->offset = 0;
 353         sg->length = size;
 354
 355         sg_dma_address(sg) = (dma_addr_t)dev_priv->mm.stolen_base + offset;
 356         sg_dma_len(sg) = size;
 357
 358         return st;
 359 }
 360 #endif
 361
 362 static int i915_gem_object_get_pages_stolen(struct drm_i915_gem_object *obj)
 363 {
 364         BUG();
 365         return -EINVAL;
 366 }
 367
 368 static void i915_gem_object_put_pages_stolen(struct drm_i915_gem_object *obj)
 369 {
 370 #if 0
 371         /* Should only be called during free */
 372         sg_free_table(obj->pages);
 373         kfree(obj->pages);
 374 #else
 375         BUG();
 376 #endif
 377 }
 378
 379
 380 static void
 381 i915_gem_object_release_stolen(struct drm_i915_gem_object *obj)
 382 {
 383         if (obj->stolen) {
 384                 drm_mm_remove_node(obj->stolen);
 385                 kfree(obj->stolen);
 386                 obj->stolen = NULL;
 387         }
 388 }
 389 static const struct drm_i915_gem_object_ops i915_gem_object_stolen_ops = {
 390         .get_pages = i915_gem_object_get_pages_stolen,
 391         .put_pages = i915_gem_object_put_pages_stolen,
 392         .release = i915_gem_object_release_stolen,
 393 };
 394
 395 static struct drm_i915_gem_object *
 396 _i915_gem_object_create_stolen(struct drm_device *dev,
 397                                struct drm_mm_node *stolen)
 398 {
 399         struct drm_i915_gem_object *obj;
 400
 401 #if 0
 402         obj = i915_gem_object_alloc(dev);
 403 #else
 404         obj = NULL;
 405 #endif
 406         if (obj == NULL)
 407                 return NULL;
 408
 409         drm_gem_private_object_init(dev, &obj->base, stolen->size);
 410         i915_gem_object_init(obj, &i915_gem_object_stolen_ops);
 411
 412 #if 0
 413         obj->pages = i915_pages_create_for_stolen(dev,
 414                                                   stolen->start, stolen->size);
 415 #else
 416         obj->pages = NULL;
 417 #endif
 418         if (obj->pages == NULL)
 419                 goto cleanup;
 420
 421         obj->has_dma_mapping = true;
 422         i915_gem_object_pin_pages(obj);
 423         obj->stolen = stolen;
 424
 425         obj->base.read_domains = I915_GEM_DOMAIN_CPU | I915_GEM_DOMAIN_GTT;
 426         obj->cache_level = HAS_LLC(dev) ? I915_CACHE_LLC : I915_CACHE_NONE;
 427
 428         return obj;
 429
 430 cleanup:
 431         i915_gem_object_free(obj);
 432         return NULL;
 433 }
 434
 435 struct drm_i915_gem_object *
 436 i915_gem_object_create_stolen(struct drm_device *dev, u32 size)
 437 {
 438         struct drm_i915_private *dev_priv = dev->dev_private;
 439         struct drm_i915_gem_object *obj;
 440         struct drm_mm_node *stolen;
 441         int ret;
 442
 443         if (!drm_mm_initialized(&dev_priv->mm.stolen))
 444                 return NULL;
 445
 446         DRM_DEBUG_KMS("creating stolen object: size=%x\n", size);
 447         if (size == 0)
 448                 return NULL;
 449
 450         stolen = kzalloc(sizeof(*stolen), GFP_KERNEL);
 451         if (!stolen)
 452                 return NULL;
 453
 454         ret = drm_mm_insert_node(&dev_priv->mm.stolen, stolen, size,
 455                                  4096, DRM_MM_SEARCH_DEFAULT);
 456         if (ret) {
 457                 kfree(stolen);
 458                 return NULL;
 459         }
 460
 461         obj = _i915_gem_object_create_stolen(dev, stolen);
 462         if (obj)
 463                 return obj;
 464
 465         drm_mm_remove_node(stolen);
 466         kfree(stolen);
 467         return NULL;
 468 }
 469
 470 struct drm_i915_gem_object *
 471 i915_gem_object_create_stolen_for_preallocated(struct drm_device *dev,
 472                                                u32 stolen_offset,
 473                                                u32 gtt_offset,
 474                                                u32 size)
 475 {
 476         struct drm_i915_private *dev_priv = dev->dev_private;
 477         struct i915_address_space *ggtt = &dev_priv->gtt.base;
 478         struct drm_i915_gem_object *obj;
 479         struct drm_mm_node *stolen;
 480         struct i915_vma *vma;
 481         int ret;
 482
 483         if (!drm_mm_initialized(&dev_priv->mm.stolen))
 484                 return NULL;
 485
 486         DRM_DEBUG_KMS("creating preallocated stolen object: stolen_offset=%x, gtt_offset=%x, size=%x\n",
 487                         stolen_offset, gtt_offset, size);
 488
 489         /* KISS and expect everything to be page-aligned */
 490         BUG_ON(stolen_offset & 4095);
 491         BUG_ON(size & 4095);
 492
 493         if (WARN_ON(size == 0))
 494                 return NULL;
 495
 496         stolen = kzalloc(sizeof(*stolen), GFP_KERNEL);
 497         if (!stolen)
 498                 return NULL;
 499
 500         stolen->start = stolen_offset;
 501         stolen->size = size;
 502         ret = drm_mm_reserve_node(&dev_priv->mm.stolen, stolen);
 503         if (ret) {
 504                 DRM_DEBUG_KMS("failed to allocate stolen space\n");
 505                 kfree(stolen);
 506                 return NULL;
 507         }
 508
 509         obj = _i915_gem_object_create_stolen(dev, stolen);
 510         if (obj == NULL) {
 511                 DRM_DEBUG_KMS("failed to allocate stolen object\n");
 512                 drm_mm_remove_node(stolen);
 513                 kfree(stolen);
 514                 return NULL;
 515         }
 516
 517         /* Some objects just need physical mem from stolen space */
 518         if (gtt_offset == I915_GTT_OFFSET_NONE)
 519                 return obj;
 520
 521         vma = i915_gem_obj_lookup_or_create_vma(obj, ggtt);
 522         if (IS_ERR(vma)) {
 523                 ret = PTR_ERR(vma);
 524                 goto err_out;
 525         }
 526
 527         /* To simplify the initialisation sequence between KMS and GTT,
 528          * we allow construction of the stolen object prior to
 529          * setting up the GTT space. The actual reservation will occur
 530          * later.
 531          */
 532         vma->node.start = gtt_offset;
 533         vma->node.size = size;
 534         if (drm_mm_initialized(&ggtt->mm)) {
 535                 ret = drm_mm_reserve_node(&ggtt->mm, &vma->node);
 536                 if (ret) {
 537                         DRM_DEBUG_KMS("failed to allocate stolen GTT space\n");
 538                         goto err_vma;
 539                 }
 540         }
 541
 542         obj->has_global_gtt_mapping = 1;
 543
 544         list_add_tail(&obj->global_list, &dev_priv->mm.bound_list);
 545         list_add_tail(&vma->mm_list, &ggtt->inactive_list);
 546         i915_gem_object_pin_pages(obj);
 547
 548         return obj;
 549
 550 err_vma:
 551         i915_gem_vma_destroy(vma);
 552 err_out:
 553         drm_mm_remove_node(stolen);
 554         kfree(stolen);
 555         drm_gem_object_unreference(&obj->base);
 556         return NULL;
 557 }