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 /*
  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         struct resource *r;
  49         u32 base;
  50
  51         /* Almost universally we can find the Graphics Base of Stolen Memory
  52          * at offset 0x5c in the igfx configuration space. On a few (desktop)
  53          * machines this is also mirrored in the bridge device at different
  54          * locations, or in the MCHBAR. On gen2, the layout is again slightly
  55          * different with the Graphics Segment immediately following Top of
  56          * Memory (or Top of Usable DRAM). Note it appears that TOUD is only
  57          * reported by 865g, so we just use the top of memory as determined
  58          * by the e820 probe.
  59          *
  60          * XXX However gen2 requires an unavailable symbol.
  61          */
  62         base = 0;
  63         if (INTEL_INFO(dev)->gen >= 3) {
  64                 /* Read Graphics Base of Stolen Memory directly */
  65                 pci_read_config_dword(dev->pdev, 0x5c, &base);
  66                 base &= ~((1<<20) - 1);
  67         } else { /* GEN2 */
  68 #if 0
  69                 /* Stolen is immediately above Top of Memory */
  70                 base = max_low_pfn_mapped << PAGE_SHIFT;
  71 #endif
  72         }
  73
  74         if (base == 0)
  75                 return 0;
  76
  77         /* make sure we don't clobber the GTT if it's within stolen memory */
  78         if (INTEL_INFO(dev)->gen <= 4 && !IS_G33(dev) && !IS_G4X(dev)) {
  79                 struct {
  80                         u32 start, end;
  81                 } stolen[2] = {
  82                         { .start = base, .end = base + dev_priv->gtt.stolen_size, },
  83                         { .start = base, .end = base + dev_priv->gtt.stolen_size, },
  84                 };
  85                 u64 gtt_start, gtt_end;
  86
  87                 gtt_start = I915_READ(PGTBL_CTL);
  88                 if (IS_GEN4(dev))
  89                         gtt_start = (gtt_start & PGTBL_ADDRESS_LO_MASK) |
  90                                 (gtt_start & PGTBL_ADDRESS_HI_MASK) << 28;
  91                 else
  92                         gtt_start &= PGTBL_ADDRESS_LO_MASK;
  93                 gtt_end = gtt_start + gtt_total_entries(dev_priv->gtt) * 4;
  94
  95                 if (gtt_start >= stolen[0].start && gtt_start < stolen[0].end)
  96                         stolen[0].end = gtt_start;
  97                 if (gtt_end > stolen[1].start && gtt_end <= stolen[1].end)
  98                         stolen[1].start = gtt_end;
  99
 100                 /* pick the larger of the two chunks */
 101                 if (stolen[0].end - stolen[0].start >
 102                     stolen[1].end - stolen[1].start) {
 103                         base = stolen[0].start;
 104                         dev_priv->gtt.stolen_size = stolen[0].end - stolen[0].start;
 105                 } else {
 106                         base = stolen[1].start;
 107                         dev_priv->gtt.stolen_size = stolen[1].end - stolen[1].start;
 108                 }
 109
 110                 if (stolen[0].start != stolen[1].start ||
 111                     stolen[0].end != stolen[1].end) {
 112                         DRM_DEBUG_KMS("GTT within stolen memory at 0x%llx-0x%llx\n",
 113                                       (unsigned long long) gtt_start,
 114                                       (unsigned long long) gtt_end - 1);
 115                         DRM_DEBUG_KMS("Stolen memory adjusted to 0x%x-0x%x\n",
 116                                       base, base + (u32) dev_priv->gtt.stolen_size - 1);
 117                 }
 118         }
 119
 120
 121         /* Verify that nothing else uses this physical address. Stolen
 122          * memory should be reserved by the BIOS and hidden from the
 123          * kernel. So if the region is already marked as busy, something
 124          * is seriously wrong.
 125          */
 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                 /*
 141                  * GEN3 firmware likes to smash pci bridges into the stolen
 142                  * range. Apparently this works.
 143                  */
 144                 if (r == NULL && !IS_GEN3(dev)) {
 145                         DRM_ERROR("conflict detected with stolen region: [0x%08x - 0x%08x]\n",
 146                                   base, base + (uint32_t)dev_priv->gtt.stolen_size);
 147                         base = 0;
 148                 }
 149         }
 150
 151         return base;
 152 }
 153
 154 static int find_compression_threshold(struct drm_device *dev,
 155                                       struct drm_mm_node *node,
 156                                       int size,
 157                                       int fb_cpp)
 158 {
 159         struct drm_i915_private *dev_priv = dev->dev_private;
 160         int compression_threshold = 1;
 161         int ret;
 162
 163         /* HACK: This code depends on what we will do in *_enable_fbc. If that
 164          * code changes, this code needs to change as well.
 165          *
 166          * The enable_fbc code will attempt to use one of our 2 compression
 167          * thresholds, therefore, in that case, we only have 1 resort.
 168          */
 169
 170         /* Try to over-allocate to reduce reallocations and fragmentation. */
 171         ret = drm_mm_insert_node(&dev_priv->mm.stolen, node,
 172                                  size <<= 1, 4096, DRM_MM_SEARCH_DEFAULT);
 173         if (ret == 0)
 174                 return compression_threshold;
 175
 176 again:
 177         /* HW's ability to limit the CFB is 1:4 */
 178         if (compression_threshold > 4 ||
 179             (fb_cpp == 2 && compression_threshold == 2))
 180                 return 0;
 181
 182         ret = drm_mm_insert_node(&dev_priv->mm.stolen, node,
 183                                  size >>= 1, 4096,
 184                                  DRM_MM_SEARCH_DEFAULT);
 185         if (ret && INTEL_INFO(dev)->gen <= 4) {
 186                 return 0;
 187         } else if (ret) {
 188                 compression_threshold <<= 1;
 189                 goto again;
 190         } else {
 191                 return compression_threshold;
 192         }
 193 }
 194
 195 static int i915_setup_compression(struct drm_device *dev, int size, int fb_cpp)
 196 {
 197         struct drm_i915_private *dev_priv = dev->dev_private;
 198         struct drm_mm_node *uninitialized_var(compressed_llb);
 199         int ret;
 200
 201         ret = find_compression_threshold(dev, &dev_priv->fbc.compressed_fb,
 202                                          size, fb_cpp);
 203         if (!ret)
 204                 goto err_llb;
 205         else if (ret > 1) {
 206                 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");
 207
 208         }
 209
 210         dev_priv->fbc.threshold = ret;
 211
 212         if (INTEL_INFO(dev_priv)->gen >= 5)
 213                 I915_WRITE(ILK_DPFC_CB_BASE, dev_priv->fbc.compressed_fb.start);
 214         else if (IS_GM45(dev)) {
 215                 I915_WRITE(DPFC_CB_BASE, dev_priv->fbc.compressed_fb.start);
 216         } else {
 217                 compressed_llb = kzalloc(sizeof(*compressed_llb), GFP_KERNEL);
 218                 if (!compressed_llb)
 219                         goto err_fb;
 220
 221                 ret = drm_mm_insert_node(&dev_priv->mm.stolen, compressed_llb,
 222                                          4096, 4096, DRM_MM_SEARCH_DEFAULT);
 223                 if (ret)
 224                         goto err_fb;
 225
 226                 dev_priv->fbc.compressed_llb = compressed_llb;
 227
 228                 I915_WRITE(FBC_CFB_BASE,
 229                            dev_priv->mm.stolen_base + dev_priv->fbc.compressed_fb.start);
 230                 I915_WRITE(FBC_LL_BASE,
 231                            dev_priv->mm.stolen_base + compressed_llb->start);
 232         }
 233
 234         dev_priv->fbc.uncompressed_size = size;
 235
 236         DRM_DEBUG_KMS("reserved %d bytes of contiguous stolen space for FBC\n",
 237                       size);
 238
 239         return 0;
 240
 241 err_fb:
 242         kfree(compressed_llb);
 243         drm_mm_remove_node(&dev_priv->fbc.compressed_fb);
 244 err_llb:
 245         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);
 246         return -ENOSPC;
 247 }
 248
 249 int i915_gem_stolen_setup_compression(struct drm_device *dev, int size, int fb_cpp)
 250 {
 251         struct drm_i915_private *dev_priv = dev->dev_private;
 252
 253         if (!drm_mm_initialized(&dev_priv->mm.stolen))
 254                 return -ENODEV;
 255
 256         if (size <= dev_priv->fbc.uncompressed_size)
 257                 return 0;
 258
 259         /* Release any current block */
 260         i915_gem_stolen_cleanup_compression(dev);
 261
 262         return i915_setup_compression(dev, size, fb_cpp);
 263 }
 264
 265 void i915_gem_stolen_cleanup_compression(struct drm_device *dev)
 266 {
 267         struct drm_i915_private *dev_priv = dev->dev_private;
 268
 269         if (dev_priv->fbc.uncompressed_size == 0)
 270                 return;
 271
 272         drm_mm_remove_node(&dev_priv->fbc.compressed_fb);
 273
 274         if (dev_priv->fbc.compressed_llb) {
 275                 drm_mm_remove_node(dev_priv->fbc.compressed_llb);
 276                 kfree(dev_priv->fbc.compressed_llb);
 277         }
 278
 279         dev_priv->fbc.uncompressed_size = 0;
 280 }
 281
 282 void i915_gem_cleanup_stolen(struct drm_device *dev)
 283 {
 284         struct drm_i915_private *dev_priv = dev->dev_private;
 285
 286         if (!drm_mm_initialized(&dev_priv->mm.stolen))
 287                 return;
 288
 289         i915_gem_stolen_cleanup_compression(dev);
 290         drm_mm_takedown(&dev_priv->mm.stolen);
 291 }
 292
 293 int i915_gem_init_stolen(struct drm_device *dev)
 294 {
 295         struct drm_i915_private *dev_priv = dev->dev_private;
 296         u32 tmp;
 297         int bios_reserved = 0;
 298
 299 #ifdef CONFIG_INTEL_IOMMU
 300         if (intel_iommu_gfx_mapped && INTEL_INFO(dev)->gen < 8) {
 301                 DRM_INFO("DMAR active, disabling use of stolen memory\n");
 302                 return 0;
 303         }
 304 #endif
 305
 306         if (dev_priv->gtt.stolen_size == 0)
 307                 return 0;
 308
 309         dev_priv->mm.stolen_base = i915_stolen_to_physical(dev);
 310         if (dev_priv->mm.stolen_base == 0)
 311                 return 0;
 312
 313         DRM_DEBUG_KMS("found %zd bytes of stolen memory at %08lx\n",
 314                       dev_priv->gtt.stolen_size, dev_priv->mm.stolen_base);
 315
 316         if (INTEL_INFO(dev)->gen >= 8) {
 317                 tmp = I915_READ(GEN7_BIOS_RESERVED);
 318                 tmp >>= GEN8_BIOS_RESERVED_SHIFT;
 319                 tmp &= GEN8_BIOS_RESERVED_MASK;
 320                 bios_reserved = (1024*1024) << tmp;
 321         } else if (IS_GEN7(dev)) {
 322                 tmp = I915_READ(GEN7_BIOS_RESERVED);
 323                 bios_reserved = tmp & GEN7_BIOS_RESERVED_256K ?
 324                         256*1024 : 1024*1024;
 325         }
 326
 327         if (WARN_ON(bios_reserved > dev_priv->gtt.stolen_size))
 328                 return 0;
 329
 330         /* Basic memrange allocator for stolen space */
 331         drm_mm_init(&dev_priv->mm.stolen, 0, dev_priv->gtt.stolen_size -
 332                     bios_reserved);
 333
 334         return 0;
 335 }
 336
 337 static struct sg_table *
 338 i915_pages_create_for_stolen(struct drm_device *dev,
 339                              u32 offset, u32 size)
 340 {
 341         struct drm_i915_private *dev_priv = dev->dev_private;
 342         struct sg_table *st;
 343         struct scatterlist *sg;
 344
 345         DRM_DEBUG_DRIVER("offset=0x%x, size=%d\n", offset, size);
 346         BUG_ON(offset > dev_priv->gtt.stolen_size - size);
 347
 348         /* We hide that we have no struct page backing our stolen object
 349          * by wrapping the contiguous physical allocation with a fake
 350          * dma mapping in a single scatterlist.
 351          */
 352
 353         st = kmalloc(sizeof(*st), GFP_KERNEL);
 354         if (st == NULL)
 355                 return NULL;
 356
 357         if (sg_alloc_table(st, 1, GFP_KERNEL)) {
 358                 kfree(st);
 359                 return NULL;
 360         }
 361
 362         sg = st->sgl;
 363         sg->offset = 0;
 364         sg->length = size;
 365
 366         sg_dma_address(sg) = (dma_addr_t)dev_priv->mm.stolen_base + offset;
 367         sg_dma_len(sg) = size;
 368
 369         return st;
 370 }
 371
 372 static int i915_gem_object_get_pages_stolen(struct drm_i915_gem_object *obj)
 373 {
 374         BUG();
 375         return -EINVAL;
 376 }
 377
 378 static void i915_gem_object_put_pages_stolen(struct drm_i915_gem_object *obj)
 379 {
 380         /* Should only be called during free */
 381         sg_free_table(obj->pages);
 382         kfree(obj->pages);
 383 }
 384
 385
 386 static void
 387 i915_gem_object_release_stolen(struct drm_i915_gem_object *obj)
 388 {
 389         if (obj->stolen) {
 390                 drm_mm_remove_node(obj->stolen);
 391                 kfree(obj->stolen);
 392                 obj->stolen = NULL;
 393         }
 394 }
 395 static const struct drm_i915_gem_object_ops i915_gem_object_stolen_ops = {
 396         .get_pages = i915_gem_object_get_pages_stolen,
 397         .put_pages = i915_gem_object_put_pages_stolen,
 398         .release = i915_gem_object_release_stolen,
 399 };
 400
 401 static struct drm_i915_gem_object *
 402 _i915_gem_object_create_stolen(struct drm_device *dev,
 403                                struct drm_mm_node *stolen)
 404 {
 405         struct drm_i915_gem_object *obj;
 406
 407         obj = i915_gem_object_alloc(dev);
 408         if (obj == NULL)
 409                 return NULL;
 410
 411         drm_gem_private_object_init(dev, &obj->base, stolen->size);
 412         i915_gem_object_init(obj, &i915_gem_object_stolen_ops);
 413
 414         obj->pages = i915_pages_create_for_stolen(dev,
 415                                                   stolen->start, stolen->size);
 416         if (obj->pages == NULL)
 417                 goto cleanup;
 418
 419         i915_gem_object_pin_pages(obj);
 420         obj->stolen = stolen;
 421
 422         obj->base.read_domains = I915_GEM_DOMAIN_CPU | I915_GEM_DOMAIN_GTT;
 423         obj->cache_level = HAS_LLC(dev) ? I915_CACHE_LLC : I915_CACHE_NONE;
 424
 425         return obj;
 426
 427 cleanup:
 428         i915_gem_object_free(obj);
 429         return NULL;
 430 }
 431
 432 struct drm_i915_gem_object *
 433 i915_gem_object_create_stolen(struct drm_device *dev, u32 size)
 434 {
 435         struct drm_i915_private *dev_priv = dev->dev_private;
 436         struct drm_i915_gem_object *obj;
 437         struct drm_mm_node *stolen;
 438         int ret;
 439
 440         if (!drm_mm_initialized(&dev_priv->mm.stolen))
 441                 return NULL;
 442
 443         DRM_DEBUG_KMS("creating stolen object: size=%x\n", size);
 444         if (size == 0)
 445                 return NULL;
 446
 447         stolen = kzalloc(sizeof(*stolen), GFP_KERNEL);
 448         if (!stolen)
 449                 return NULL;
 450
 451         ret = drm_mm_insert_node(&dev_priv->mm.stolen, stolen, size,
 452                                  4096, DRM_MM_SEARCH_DEFAULT);
 453         if (ret) {
 454                 kfree(stolen);
 455                 return NULL;
 456         }
 457
 458         obj = _i915_gem_object_create_stolen(dev, stolen);
 459         if (obj)
 460                 return obj;
 461
 462         drm_mm_remove_node(stolen);
 463         kfree(stolen);
 464         return NULL;
 465 }
 466
 467 struct drm_i915_gem_object *
 468 i915_gem_object_create_stolen_for_preallocated(struct drm_device *dev,
 469                                                u32 stolen_offset,
 470                                                u32 gtt_offset,
 471                                                u32 size)
 472 {
 473         struct drm_i915_private *dev_priv = dev->dev_private;
 474         struct i915_address_space *ggtt = &dev_priv->gtt.base;
 475         struct drm_i915_gem_object *obj;
 476         struct drm_mm_node *stolen;
 477         struct i915_vma *vma;
 478         int ret;
 479
 480         if (!drm_mm_initialized(&dev_priv->mm.stolen))
 481                 return NULL;
 482
 483         DRM_DEBUG_KMS("creating preallocated stolen object: stolen_offset=%x, gtt_offset=%x, size=%x\n",
 484                         stolen_offset, gtt_offset, size);
 485
 486         /* KISS and expect everything to be page-aligned */
 487         if (WARN_ON(size == 0) || WARN_ON(size & 4095) ||
 488             WARN_ON(stolen_offset & 4095))
 489                 return NULL;
 490
 491         stolen = kzalloc(sizeof(*stolen), GFP_KERNEL);
 492         if (!stolen)
 493                 return NULL;
 494
 495         stolen->start = stolen_offset;
 496         stolen->size = size;
 497         ret = drm_mm_reserve_node(&dev_priv->mm.stolen, stolen);
 498         if (ret) {
 499                 DRM_DEBUG_KMS("failed to allocate stolen space\n");
 500                 kfree(stolen);
 501                 return NULL;
 502         }
 503
 504         obj = _i915_gem_object_create_stolen(dev, stolen);
 505         if (obj == NULL) {
 506                 DRM_DEBUG_KMS("failed to allocate stolen object\n");
 507                 drm_mm_remove_node(stolen);
 508                 kfree(stolen);
 509                 return NULL;
 510         }
 511
 512         /* Some objects just need physical mem from stolen space */
 513         if (gtt_offset == I915_GTT_OFFSET_NONE)
 514                 return obj;
 515
 516         vma = i915_gem_obj_lookup_or_create_vma(obj, ggtt);
 517         if (IS_ERR(vma)) {
 518                 ret = PTR_ERR(vma);
 519                 goto err_out;
 520         }
 521
 522         /* To simplify the initialisation sequence between KMS and GTT,
 523          * we allow construction of the stolen object prior to
 524          * setting up the GTT space. The actual reservation will occur
 525          * later.
 526          */
 527         vma->node.start = gtt_offset;
 528         vma->node.size = size;
 529         if (drm_mm_initialized(&ggtt->mm)) {
 530                 ret = drm_mm_reserve_node(&ggtt->mm, &vma->node);
 531                 if (ret) {
 532                         DRM_DEBUG_KMS("failed to allocate stolen GTT space\n");
 533                         goto err_vma;
 534                 }
 535         }
 536
 537         vma->bound |= GLOBAL_BIND;
 538
 539         list_add_tail(&obj->global_list, &dev_priv->mm.bound_list);
 540         list_add_tail(&vma->mm_list, &ggtt->inactive_list);
 541         i915_gem_object_pin_pages(obj);
 542
 543         return obj;
 544
 545 err_vma:
 546         i915_gem_vma_destroy(vma);
 547 err_out:
 548         drm_mm_remove_node(stolen);
 549         kfree(stolen);
 550         drm_gem_object_unreference(&obj->base);
 551         return NULL;
 552 }