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                 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
 147         return base;
 148 }
 149
 150 static int find_compression_threshold(struct drm_device *dev,
 151                                       struct drm_mm_node *node,
 152                                       int size,
 153                                       int fb_cpp)
 154 {
 155         struct drm_i915_private *dev_priv = dev->dev_private;
 156         int compression_threshold = 1;
 157         int ret;
 158
 159         /* HACK: This code depends on what we will do in *_enable_fbc. If that
 160          * code changes, this code needs to change as well.
 161          *
 162          * The enable_fbc code will attempt to use one of our 2 compression
 163          * thresholds, therefore, in that case, we only have 1 resort.
 164          */
 165
 166         /* Try to over-allocate to reduce reallocations and fragmentation. */
 167         ret = drm_mm_insert_node(&dev_priv->mm.stolen, node,
 168                                  size <<= 1, 4096, DRM_MM_SEARCH_DEFAULT);
 169         if (ret == 0)
 170                 return compression_threshold;
 171
 172 again:
 173         /* HW's ability to limit the CFB is 1:4 */
 174         if (compression_threshold > 4 ||
 175             (fb_cpp == 2 && compression_threshold == 2))
 176                 return 0;
 177
 178         ret = drm_mm_insert_node(&dev_priv->mm.stolen, node,
 179                                  size >>= 1, 4096,
 180                                  DRM_MM_SEARCH_DEFAULT);
 181         if (ret && INTEL_INFO(dev)->gen <= 4) {
 182                 return 0;
 183         } else if (ret) {
 184                 compression_threshold <<= 1;
 185                 goto again;
 186         } else {
 187                 return compression_threshold;
 188         }
 189 }
 190
 191 static int i915_setup_compression(struct drm_device *dev, int size, int fb_cpp)
 192 {
 193         struct drm_i915_private *dev_priv = dev->dev_private;
 194         struct drm_mm_node *uninitialized_var(compressed_llb);
 195         int ret;
 196
 197         ret = find_compression_threshold(dev, &dev_priv->fbc.compressed_fb,
 198                                          size, fb_cpp);
 199         if (!ret)
 200                 goto err_llb;
 201         else if (ret > 1) {
 202                 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");
 203
 204         }
 205
 206         dev_priv->fbc.threshold = ret;
 207
 208         if (HAS_PCH_SPLIT(dev))
 209                 I915_WRITE(ILK_DPFC_CB_BASE, dev_priv->fbc.compressed_fb.start);
 210         else if (IS_GM45(dev)) {
 211                 I915_WRITE(DPFC_CB_BASE, dev_priv->fbc.compressed_fb.start);
 212         } else {
 213                 compressed_llb = kzalloc(sizeof(*compressed_llb), GFP_KERNEL);
 214                 if (!compressed_llb)
 215                         goto err_fb;
 216
 217                 ret = drm_mm_insert_node(&dev_priv->mm.stolen, compressed_llb,
 218                                          4096, 4096, DRM_MM_SEARCH_DEFAULT);
 219                 if (ret)
 220                         goto err_fb;
 221
 222                 dev_priv->fbc.compressed_llb = compressed_llb;
 223
 224                 I915_WRITE(FBC_CFB_BASE,
 225                            dev_priv->mm.stolen_base + dev_priv->fbc.compressed_fb.start);
 226                 I915_WRITE(FBC_LL_BASE,
 227                            dev_priv->mm.stolen_base + compressed_llb->start);
 228         }
 229
 230         dev_priv->fbc.size = size / dev_priv->fbc.threshold;
 231
 232         DRM_DEBUG_KMS("reserved %d bytes of contiguous stolen space for FBC\n",
 233                       size);
 234
 235         return 0;
 236
 237 err_fb:
 238         kfree(compressed_llb);
 239         drm_mm_remove_node(&dev_priv->fbc.compressed_fb);
 240 err_llb:
 241         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);
 242         return -ENOSPC;
 243 }
 244
 245 int i915_gem_stolen_setup_compression(struct drm_device *dev, int size, int fb_cpp)
 246 {
 247         struct drm_i915_private *dev_priv = dev->dev_private;
 248
 249         if (!drm_mm_initialized(&dev_priv->mm.stolen))
 250                 return -ENODEV;
 251
 252         if (size < dev_priv->fbc.size)
 253                 return 0;
 254
 255         /* Release any current block */
 256         i915_gem_stolen_cleanup_compression(dev);
 257
 258         return i915_setup_compression(dev, size, fb_cpp);
 259 }
 260
 261 void i915_gem_stolen_cleanup_compression(struct drm_device *dev)
 262 {
 263         struct drm_i915_private *dev_priv = dev->dev_private;
 264
 265         if (dev_priv->fbc.size == 0)
 266                 return;
 267
 268         drm_mm_remove_node(&dev_priv->fbc.compressed_fb);
 269
 270         if (dev_priv->fbc.compressed_llb) {
 271                 drm_mm_remove_node(dev_priv->fbc.compressed_llb);
 272                 kfree(dev_priv->fbc.compressed_llb);
 273         }
 274
 275         dev_priv->fbc.size = 0;
 276 }
 277
 278 void i915_gem_cleanup_stolen(struct drm_device *dev)
 279 {
 280         struct drm_i915_private *dev_priv = dev->dev_private;
 281
 282         if (!drm_mm_initialized(&dev_priv->mm.stolen))
 283                 return;
 284
 285         i915_gem_stolen_cleanup_compression(dev);
 286         drm_mm_takedown(&dev_priv->mm.stolen);
 287 }
 288
 289 int i915_gem_init_stolen(struct drm_device *dev)
 290 {
 291         struct drm_i915_private *dev_priv = dev->dev_private;
 292         u32 tmp;
 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 (INTEL_INFO(dev)->gen >= 8) {
 313                 tmp = I915_READ(GEN7_BIOS_RESERVED);
 314                 tmp >>= GEN8_BIOS_RESERVED_SHIFT;
 315                 tmp &= GEN8_BIOS_RESERVED_MASK;
 316                 bios_reserved = (1024*1024) << tmp;
 317         } else if (IS_GEN7(dev)) {
 318                 tmp = I915_READ(GEN7_BIOS_RESERVED);
 319                 bios_reserved = tmp & GEN7_BIOS_RESERVED_256K ?
 320                         256*1024 : 1024*1024;
 321         }
 322
 323         if (WARN_ON(bios_reserved > dev_priv->gtt.stolen_size))
 324                 return 0;
 325
 326         /* Basic memrange allocator for stolen space */
 327         drm_mm_init(&dev_priv->mm.stolen, 0, dev_priv->gtt.stolen_size -
 328                     bios_reserved);
 329
 330         return 0;
 331 }
 332
 333 static struct sg_table *
 334 i915_pages_create_for_stolen(struct drm_device *dev,
 335                              u32 offset, u32 size)
 336 {
 337         struct drm_i915_private *dev_priv = dev->dev_private;
 338         struct sg_table *st;
 339         struct scatterlist *sg;
 340
 341         DRM_DEBUG_DRIVER("offset=0x%x, size=%d\n", offset, size);
 342         BUG_ON(offset > dev_priv->gtt.stolen_size - size);
 343
 344         /* We hide that we have no struct page backing our stolen object
 345          * by wrapping the contiguous physical allocation with a fake
 346          * dma mapping in a single scatterlist.
 347          */
 348
 349         st = kmalloc(sizeof(*st), GFP_KERNEL);
 350         if (st == NULL)
 351                 return NULL;
 352
 353         if (sg_alloc_table(st, 1, GFP_KERNEL)) {
 354                 kfree(st);
 355                 return NULL;
 356         }
 357
 358         sg = st->sgl;
 359         sg->offset = 0;
 360         sg->length = size;
 361
 362         sg_dma_address(sg) = (dma_addr_t)dev_priv->mm.stolen_base + offset;
 363         sg_dma_len(sg) = size;
 364
 365         return st;
 366 }
 367
 368 static int i915_gem_object_get_pages_stolen(struct drm_i915_gem_object *obj)
 369 {
 370         BUG();
 371         return -EINVAL;
 372 }
 373
 374 static void i915_gem_object_put_pages_stolen(struct drm_i915_gem_object *obj)
 375 {
 376         /* Should only be called during free */
 377         sg_free_table(obj->pages);
 378         kfree(obj->pages);
 379 }
 380
 381
 382 static void
 383 i915_gem_object_release_stolen(struct drm_i915_gem_object *obj)
 384 {
 385         if (obj->stolen) {
 386                 drm_mm_remove_node(obj->stolen);
 387                 kfree(obj->stolen);
 388                 obj->stolen = NULL;
 389         }
 390 }
 391 static const struct drm_i915_gem_object_ops i915_gem_object_stolen_ops = {
 392         .get_pages = i915_gem_object_get_pages_stolen,
 393         .put_pages = i915_gem_object_put_pages_stolen,
 394         .release = i915_gem_object_release_stolen,
 395 };
 396
 397 static struct drm_i915_gem_object *
 398 _i915_gem_object_create_stolen(struct drm_device *dev,
 399                                struct drm_mm_node *stolen)
 400 {
 401         struct drm_i915_gem_object *obj;
 402
 403         obj = i915_gem_object_alloc(dev);
 404         if (obj == NULL)
 405                 return NULL;
 406
 407         drm_gem_private_object_init(dev, &obj->base, stolen->size);
 408         i915_gem_object_init(obj, &i915_gem_object_stolen_ops);
 409
 410         obj->pages = i915_pages_create_for_stolen(dev,
 411                                                   stolen->start, stolen->size);
 412         if (obj->pages == NULL)
 413                 goto cleanup;
 414
 415         obj->has_dma_mapping = true;
 416         i915_gem_object_pin_pages(obj);
 417         obj->stolen = stolen;
 418
 419         obj->base.read_domains = I915_GEM_DOMAIN_CPU | I915_GEM_DOMAIN_GTT;
 420         obj->cache_level = HAS_LLC(dev) ? I915_CACHE_LLC : I915_CACHE_NONE;
 421
 422         return obj;
 423
 424 cleanup:
 425         i915_gem_object_free(obj);
 426         return NULL;
 427 }
 428
 429 struct drm_i915_gem_object *
 430 i915_gem_object_create_stolen(struct drm_device *dev, u32 size)
 431 {
 432         struct drm_i915_private *dev_priv = dev->dev_private;
 433         struct drm_i915_gem_object *obj;
 434         struct drm_mm_node *stolen;
 435         int ret;
 436
 437         if (!drm_mm_initialized(&dev_priv->mm.stolen))
 438                 return NULL;
 439
 440         DRM_DEBUG_KMS("creating stolen object: size=%x\n", size);
 441         if (size == 0)
 442                 return NULL;
 443
 444         stolen = kzalloc(sizeof(*stolen), GFP_KERNEL);
 445         if (!stolen)
 446                 return NULL;
 447
 448         ret = drm_mm_insert_node(&dev_priv->mm.stolen, stolen, size,
 449                                  4096, DRM_MM_SEARCH_DEFAULT);
 450         if (ret) {
 451                 kfree(stolen);
 452                 return NULL;
 453         }
 454
 455         obj = _i915_gem_object_create_stolen(dev, stolen);
 456         if (obj)
 457                 return obj;
 458
 459         drm_mm_remove_node(stolen);
 460         kfree(stolen);
 461         return NULL;
 462 }
 463
 464 struct drm_i915_gem_object *
 465 i915_gem_object_create_stolen_for_preallocated(struct drm_device *dev,
 466                                                u32 stolen_offset,
 467                                                u32 gtt_offset,
 468                                                u32 size)
 469 {
 470         struct drm_i915_private *dev_priv = dev->dev_private;
 471         struct i915_address_space *ggtt = &dev_priv->gtt.base;
 472         struct drm_i915_gem_object *obj;
 473         struct drm_mm_node *stolen;
 474         struct i915_vma *vma;
 475         int ret;
 476
 477         if (!drm_mm_initialized(&dev_priv->mm.stolen))
 478                 return NULL;
 479
 480         DRM_DEBUG_KMS("creating preallocated stolen object: stolen_offset=%x, gtt_offset=%x, size=%x\n",
 481                         stolen_offset, gtt_offset, size);
 482
 483         /* KISS and expect everything to be page-aligned */
 484         BUG_ON(stolen_offset & 4095);
 485         BUG_ON(size & 4095);
 486
 487         if (WARN_ON(size == 0))
 488                 return NULL;
 489
 490         stolen = kzalloc(sizeof(*stolen), GFP_KERNEL);
 491         if (!stolen)
 492                 return NULL;
 493
 494         stolen->start = stolen_offset;
 495         stolen->size = size;
 496         ret = drm_mm_reserve_node(&dev_priv->mm.stolen, stolen);
 497         if (ret) {
 498                 DRM_DEBUG_KMS("failed to allocate stolen space\n");
 499                 kfree(stolen);
 500                 return NULL;
 501         }
 502
 503         obj = _i915_gem_object_create_stolen(dev, stolen);
 504         if (obj == NULL) {
 505                 DRM_DEBUG_KMS("failed to allocate stolen object\n");
 506                 drm_mm_remove_node(stolen);
 507                 kfree(stolen);
 508                 return NULL;
 509         }
 510
 511         /* Some objects just need physical mem from stolen space */
 512         if (gtt_offset == I915_GTT_OFFSET_NONE)
 513                 return obj;
 514
 515         vma = i915_gem_obj_lookup_or_create_vma(obj, ggtt);
 516         if (IS_ERR(vma)) {
 517                 ret = PTR_ERR(vma);
 518                 goto err_out;
 519         }
 520
 521         /* To simplify the initialisation sequence between KMS and GTT,
 522          * we allow construction of the stolen object prior to
 523          * setting up the GTT space. The actual reservation will occur
 524          * later.
 525          */
 526         vma->node.start = gtt_offset;
 527         vma->node.size = size;
 528         if (drm_mm_initialized(&ggtt->mm)) {
 529                 ret = drm_mm_reserve_node(&ggtt->mm, &vma->node);
 530                 if (ret) {
 531                         DRM_DEBUG_KMS("failed to allocate stolen GTT space\n");
 532                         goto err_vma;
 533                 }
 534         }
 535
 536         obj->has_global_gtt_mapping = 1;
 537
 538         list_add_tail(&obj->global_list, &dev_priv->mm.bound_list);
 539         list_add_tail(&vma->mm_list, &ggtt->inactive_list);
 540         i915_gem_object_pin_pages(obj);
 541
 542         return obj;
 543
 544 err_vma:
 545         i915_gem_vma_destroy(vma);
 546 err_out:
 547         drm_mm_remove_node(stolen);
 548         kfree(stolen);
 549         drm_gem_object_unreference(&obj->base);
 550         return NULL;
 551 }