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         int bios_reserved = 0;
 293
 294 #ifdef CONFIG_INTEL_IOMMU
 295         if (intel_iommu_gfx_mapped && INTEL_INFO(dev)->gen < 8) {
 296                 DRM_INFO("DMAR active, disabling use of stolen memory\n");
 297                 return 0;
 298         }
 299 #endif
 300
 301         if (dev_priv->gtt.stolen_size == 0)
 302                 return 0;
 303
 304         dev_priv->mm.stolen_base = i915_stolen_to_physical(dev);
 305         if (dev_priv->mm.stolen_base == 0)
 306                 return 0;
 307
 308         DRM_DEBUG_KMS("found %zd bytes of stolen memory at %08lx\n",
 309                       dev_priv->gtt.stolen_size, dev_priv->mm.stolen_base);
 310
 311         if (IS_VALLEYVIEW(dev))
 312                 bios_reserved = 1024*1024; /* top 1M on VLV/BYT */
 313
 314         if (WARN_ON(bios_reserved > dev_priv->gtt.stolen_size))
 315                 return 0;
 316
 317         /* Basic memrange allocator for stolen space */
 318         drm_mm_init(&dev_priv->mm.stolen, 0, dev_priv->gtt.stolen_size -
 319                     bios_reserved);
 320
 321         return 0;
 322 }
 323
 324 static struct sg_table *
 325 i915_pages_create_for_stolen(struct drm_device *dev,
 326                              u32 offset, u32 size)
 327 {
 328         struct drm_i915_private *dev_priv = dev->dev_private;
 329         struct sg_table *st;
 330         struct scatterlist *sg;
 331
 332         DRM_DEBUG_DRIVER("offset=0x%x, size=%d\n", offset, size);
 333         BUG_ON(offset > dev_priv->gtt.stolen_size - size);
 334
 335         /* We hide that we have no struct page backing our stolen object
 336          * by wrapping the contiguous physical allocation with a fake
 337          * dma mapping in a single scatterlist.
 338          */
 339
 340         st = kmalloc(sizeof(*st), GFP_KERNEL);
 341         if (st == NULL)
 342                 return NULL;
 343
 344         if (sg_alloc_table(st, 1, GFP_KERNEL)) {
 345                 kfree(st);
 346                 return NULL;
 347         }
 348
 349         sg = st->sgl;
 350         sg->offset = 0;
 351         sg->length = size;
 352
 353         sg_dma_address(sg) = (dma_addr_t)dev_priv->mm.stolen_base + offset;
 354         sg_dma_len(sg) = size;
 355
 356         return st;
 357 }
 358
 359 static int i915_gem_object_get_pages_stolen(struct drm_i915_gem_object *obj)
 360 {
 361         BUG();
 362         return -EINVAL;
 363 }
 364
 365 static void i915_gem_object_put_pages_stolen(struct drm_i915_gem_object *obj)
 366 {
 367         /* Should only be called during free */
 368         sg_free_table(obj->pages);
 369         kfree(obj->pages);
 370 }
 371
 372
 373 static void
 374 i915_gem_object_release_stolen(struct drm_i915_gem_object *obj)
 375 {
 376         if (obj->stolen) {
 377                 drm_mm_remove_node(obj->stolen);
 378                 kfree(obj->stolen);
 379                 obj->stolen = NULL;
 380         }
 381 }
 382 static const struct drm_i915_gem_object_ops i915_gem_object_stolen_ops = {
 383         .get_pages = i915_gem_object_get_pages_stolen,
 384         .put_pages = i915_gem_object_put_pages_stolen,
 385         .release = i915_gem_object_release_stolen,
 386 };
 387
 388 static struct drm_i915_gem_object *
 389 _i915_gem_object_create_stolen(struct drm_device *dev,
 390                                struct drm_mm_node *stolen)
 391 {
 392         struct drm_i915_gem_object *obj;
 393
 394         obj = i915_gem_object_alloc(dev);
 395         if (obj == NULL)
 396                 return NULL;
 397
 398         drm_gem_private_object_init(dev, &obj->base, stolen->size);
 399         i915_gem_object_init(obj, &i915_gem_object_stolen_ops);
 400
 401         obj->pages = i915_pages_create_for_stolen(dev,
 402                                                   stolen->start, stolen->size);
 403         if (obj->pages == NULL)
 404                 goto cleanup;
 405
 406         obj->has_dma_mapping = true;
 407         i915_gem_object_pin_pages(obj);
 408         obj->stolen = stolen;
 409
 410         obj->base.read_domains = I915_GEM_DOMAIN_CPU | I915_GEM_DOMAIN_GTT;
 411         obj->cache_level = HAS_LLC(dev) ? I915_CACHE_LLC : I915_CACHE_NONE;
 412
 413         return obj;
 414
 415 cleanup:
 416         i915_gem_object_free(obj);
 417         return NULL;
 418 }
 419
 420 struct drm_i915_gem_object *
 421 i915_gem_object_create_stolen(struct drm_device *dev, u32 size)
 422 {
 423         struct drm_i915_private *dev_priv = dev->dev_private;
 424         struct drm_i915_gem_object *obj;
 425         struct drm_mm_node *stolen;
 426         int ret;
 427
 428         if (!drm_mm_initialized(&dev_priv->mm.stolen))
 429                 return NULL;
 430
 431         DRM_DEBUG_KMS("creating stolen object: size=%x\n", size);
 432         if (size == 0)
 433                 return NULL;
 434
 435         stolen = kzalloc(sizeof(*stolen), GFP_KERNEL);
 436         if (!stolen)
 437                 return NULL;
 438
 439         ret = drm_mm_insert_node(&dev_priv->mm.stolen, stolen, size,
 440                                  4096, DRM_MM_SEARCH_DEFAULT);
 441         if (ret) {
 442                 kfree(stolen);
 443                 return NULL;
 444         }
 445
 446         obj = _i915_gem_object_create_stolen(dev, stolen);
 447         if (obj)
 448                 return obj;
 449
 450         drm_mm_remove_node(stolen);
 451         kfree(stolen);
 452         return NULL;
 453 }
 454
 455 struct drm_i915_gem_object *
 456 i915_gem_object_create_stolen_for_preallocated(struct drm_device *dev,
 457                                                u32 stolen_offset,
 458                                                u32 gtt_offset,
 459                                                u32 size)
 460 {
 461         struct drm_i915_private *dev_priv = dev->dev_private;
 462         struct i915_address_space *ggtt = &dev_priv->gtt.base;
 463         struct drm_i915_gem_object *obj;
 464         struct drm_mm_node *stolen;
 465         struct i915_vma *vma;
 466         int ret;
 467
 468         if (!drm_mm_initialized(&dev_priv->mm.stolen))
 469                 return NULL;
 470
 471         DRM_DEBUG_KMS("creating preallocated stolen object: stolen_offset=%x, gtt_offset=%x, size=%x\n",
 472                         stolen_offset, gtt_offset, size);
 473
 474         /* KISS and expect everything to be page-aligned */
 475         BUG_ON(stolen_offset & 4095);
 476         BUG_ON(size & 4095);
 477
 478         if (WARN_ON(size == 0))
 479                 return NULL;
 480
 481         stolen = kzalloc(sizeof(*stolen), GFP_KERNEL);
 482         if (!stolen)
 483                 return NULL;
 484
 485         stolen->start = stolen_offset;
 486         stolen->size = size;
 487         ret = drm_mm_reserve_node(&dev_priv->mm.stolen, stolen);
 488         if (ret) {
 489                 DRM_DEBUG_KMS("failed to allocate stolen space\n");
 490                 kfree(stolen);
 491                 return NULL;
 492         }
 493
 494         obj = _i915_gem_object_create_stolen(dev, stolen);
 495         if (obj == NULL) {
 496                 DRM_DEBUG_KMS("failed to allocate stolen object\n");
 497                 drm_mm_remove_node(stolen);
 498                 kfree(stolen);
 499                 return NULL;
 500         }
 501
 502         /* Some objects just need physical mem from stolen space */
 503         if (gtt_offset == I915_GTT_OFFSET_NONE)
 504                 return obj;
 505
 506         vma = i915_gem_obj_lookup_or_create_vma(obj, ggtt);
 507         if (IS_ERR(vma)) {
 508                 ret = PTR_ERR(vma);
 509                 goto err_out;
 510         }
 511
 512         /* To simplify the initialisation sequence between KMS and GTT,
 513          * we allow construction of the stolen object prior to
 514          * setting up the GTT space. The actual reservation will occur
 515          * later.
 516          */
 517         vma->node.start = gtt_offset;
 518         vma->node.size = size;
 519         if (drm_mm_initialized(&ggtt->mm)) {
 520                 ret = drm_mm_reserve_node(&ggtt->mm, &vma->node);
 521                 if (ret) {
 522                         DRM_DEBUG_KMS("failed to allocate stolen GTT space\n");
 523                         goto err_vma;
 524                 }
 525         }
 526
 527         obj->has_global_gtt_mapping = 1;
 528
 529         list_add_tail(&obj->global_list, &dev_priv->mm.bound_list);
 530         list_add_tail(&vma->mm_list, &ggtt->inactive_list);
 531         i915_gem_object_pin_pages(obj);
 532
 533         return obj;
 534
 535 err_vma:
 536         i915_gem_vma_destroy(vma);
 537 err_out:
 538         drm_mm_remove_node(stolen);
 539         kfree(stolen);
 540         drm_gem_object_unreference(&obj->base);
 541         return NULL;
 542 }