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 pci_dev *pdev = dev_priv->bridge_dev;
  49         struct resource *r;
  50         u32 base;
  51
  52         /* On the machines I have tested the Graphics Base of Stolen Memory
  53          * is unreliable, so on those compute the base by subtracting the
  54          * stolen memory from the Top of Low Usable DRAM which is where the
  55          * BIOS places the graphics stolen memory.
  56          *
  57          * On gen2, the layout is slightly different with the Graphics Segment
  58          * immediately following Top of Memory (or Top of Usable DRAM). Note
  59          * it appears that TOUD is only reported by 865g, so we just use the
  60          * top of memory as determined by the e820 probe.
  61          *
  62          * XXX gen2 requires an unavailable symbol and 945gm fails with
  63          * its value of TOLUD.
  64          */
  65         base = 0;
  66         if (IS_VALLEYVIEW(dev)) {
  67                 pci_read_config_dword(dev->pdev, 0x5c, &base);
  68                 base &= ~((1<<20) - 1);
  69         } else if (INTEL_INFO(dev)->gen >= 6) {
  70                 /* Read Base Data of Stolen Memory Register (BDSM) directly.
  71                  * Note that there is also a MCHBAR miror at 0x1080c0 or
  72                  * we could use device 2:0x5c instead.
  73                 */
  74                 pci_read_config_dword(pdev, 0xB0, &base);
  75                 base &= ~4095; /* lower bits used for locking register */
  76         } else if (INTEL_INFO(dev)->gen > 3 || IS_G33(dev)) {
  77                 /* Read Graphics Base of Stolen Memory directly */
  78                 pci_read_config_dword(pdev, 0xA4, &base);
  79 #if 0
  80         } else if (IS_GEN3(dev)) {
  81                 u8 val;
  82                 /* Stolen is immediately below Top of Low Usable DRAM */
  83                 pci_read_config_byte(pdev, 0x9c, &val);
  84                 base = val >> 3 << 27;
  85                 base -= dev_priv->mm.gtt->stolen_size;
  86         } else {
  87                 /* Stolen is immediately above Top of Memory */
  88                 base = max_low_pfn_mapped << PAGE_SHIFT;
  89 #endif
  90         }
  91
  92         if (base == 0)
  93                 return 0;
  94
  95         /* Verify that nothing else uses this physical address. Stolen
  96          * memory should be reserved by the BIOS and hidden from the
  97          * kernel. So if the region is already marked as busy, something
  98          * is seriously wrong.
  99          */
 100         r = devm_request_mem_region(dev->dev, base, dev_priv->gtt.stolen_size,
 101                                     "Graphics Stolen Memory");
 102         if (r == NULL) {
 103                 DRM_ERROR("conflict detected with stolen region: [0x%08x - 0x%08x]\n",
 104                           base, base + (uint32_t)dev_priv->gtt.stolen_size);
 105                 base = 0;
 106         }
 107
 108         return base;
 109 }
 110
 111 static int i915_setup_compression(struct drm_device *dev, int size)
 112 {
 113         struct drm_i915_private *dev_priv = dev->dev_private;
 114         struct drm_mm_node *compressed_fb, *uninitialized_var(compressed_llb);
 115
 116         /* Try to over-allocate to reduce reallocations and fragmentation */
 117         compressed_fb = drm_mm_search_free(&dev_priv->mm.stolen,
 118                                            size <<= 1, 4096, 0);
 119         if (!compressed_fb)
 120                 compressed_fb = drm_mm_search_free(&dev_priv->mm.stolen,
 121                                                    size >>= 1, 4096, 0);
 122         if (compressed_fb)
 123                 compressed_fb = drm_mm_get_block(compressed_fb, size, 4096);
 124         if (!compressed_fb)
 125                 goto err;
 126
 127         if (HAS_PCH_SPLIT(dev))
 128                 I915_WRITE(ILK_DPFC_CB_BASE, compressed_fb->start);
 129         else if (IS_GM45(dev)) {
 130                 I915_WRITE(DPFC_CB_BASE, compressed_fb->start);
 131         } else {
 132                 compressed_llb = drm_mm_search_free(&dev_priv->mm.stolen,
 133                                                     4096, 4096, 0);
 134                 if (compressed_llb)
 135                         compressed_llb = drm_mm_get_block(compressed_llb,
 136                                                           4096, 4096);
 137                 if (!compressed_llb)
 138                         goto err_fb;
 139
 140                 dev_priv->fbc.compressed_llb = compressed_llb;
 141
 142                 I915_WRITE(FBC_CFB_BASE,
 143                            dev_priv->mm.stolen_base + compressed_fb->start);
 144                 I915_WRITE(FBC_LL_BASE,
 145                            dev_priv->mm.stolen_base + compressed_llb->start);
 146         }
 147
 148         dev_priv->fbc.compressed_fb = compressed_fb;
 149         dev_priv->fbc.size = size;
 150
 151         DRM_DEBUG_KMS("reserved %d bytes of contiguous stolen space for FBC\n",
 152                       size);
 153
 154         return 0;
 155
 156 err_fb:
 157         drm_mm_put_block(compressed_fb);
 158 err:
 159         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);
 160         return -ENOSPC;
 161 }
 162
 163 int i915_gem_stolen_setup_compression(struct drm_device *dev, int size)
 164 {
 165         struct drm_i915_private *dev_priv = dev->dev_private;
 166
 167         if (dev_priv->mm.stolen_base == 0)
 168                 return -ENODEV;
 169
 170         if (size < dev_priv->fbc.size)
 171                 return 0;
 172
 173         /* Release any current block */
 174         i915_gem_stolen_cleanup_compression(dev);
 175
 176         return i915_setup_compression(dev, size);
 177 }
 178
 179 void i915_gem_stolen_cleanup_compression(struct drm_device *dev)
 180 {
 181         struct drm_i915_private *dev_priv = dev->dev_private;
 182
 183         if (dev_priv->fbc.size == 0)
 184                 return;
 185
 186         if (dev_priv->fbc.compressed_fb)
 187                 drm_mm_put_block(dev_priv->fbc.compressed_fb);
 188
 189         if (dev_priv->fbc.compressed_llb)
 190                 drm_mm_put_block(dev_priv->fbc.compressed_llb);
 191
 192         dev_priv->fbc.size = 0;
 193 }
 194
 195 void i915_gem_cleanup_stolen(struct drm_device *dev)
 196 {
 197         struct drm_i915_private *dev_priv = dev->dev_private;
 198
 199         i915_gem_stolen_cleanup_compression(dev);
 200         drm_mm_takedown(&dev_priv->mm.stolen);
 201 }
 202
 203 int i915_gem_init_stolen(struct drm_device *dev)
 204 {
 205         struct drm_i915_private *dev_priv = dev->dev_private;
 206         int bios_reserved = 0;
 207
 208         dev_priv->mm.stolen_base = i915_stolen_to_physical(dev);
 209         if (dev_priv->mm.stolen_base == 0)
 210                 return 0;
 211
 212         DRM_DEBUG_KMS("found %zd bytes of stolen memory at %08lx\n",
 213                       dev_priv->gtt.stolen_size, dev_priv->mm.stolen_base);
 214
 215         if (IS_VALLEYVIEW(dev))
 216                 bios_reserved = 1024*1024; /* top 1M on VLV/BYT */
 217
 218         if (WARN_ON(bios_reserved > dev_priv->gtt.stolen_size))
 219                 return 0;
 220
 221         /* Basic memrange allocator for stolen space */
 222         drm_mm_init(&dev_priv->mm.stolen, 0, dev_priv->gtt.stolen_size -
 223                     bios_reserved);
 224
 225         return 0;
 226 }
 227
 228 static struct sg_table *
 229 i915_pages_create_for_stolen(struct drm_device *dev,
 230                              u32 offset, u32 size)
 231 {
 232         struct drm_i915_private *dev_priv = dev->dev_private;
 233         struct sg_table *st;
 234         struct scatterlist *sg;
 235
 236         DRM_DEBUG_DRIVER("offset=0x%x, size=%d\n", offset, size);
 237         BUG_ON(offset > dev_priv->gtt.stolen_size - size);
 238
 239         /* We hide that we have no struct page backing our stolen object
 240          * by wrapping the contiguous physical allocation with a fake
 241          * dma mapping in a single scatterlist.
 242          */
 243
 244         st = kmalloc(sizeof(*st), GFP_KERNEL);
 245         if (st == NULL)
 246                 return NULL;
 247
 248         if (sg_alloc_table(st, 1, GFP_KERNEL)) {
 249                 kfree(st);
 250                 return NULL;
 251         }
 252
 253         sg = st->sgl;
 254         sg->offset = offset;
 255         sg->length = size;
 256
 257         sg_dma_address(sg) = (dma_addr_t)dev_priv->mm.stolen_base + offset;
 258         sg_dma_len(sg) = size;
 259
 260         return st;
 261 }
 262
 263 static int i915_gem_object_get_pages_stolen(struct drm_i915_gem_object *obj)
 264 {
 265         BUG();
 266         return -EINVAL;
 267 }
 268
 269 static void i915_gem_object_put_pages_stolen(struct drm_i915_gem_object *obj)
 270 {
 271         /* Should only be called during free */
 272         sg_free_table(obj->pages);
 273         kfree(obj->pages);
 274 }
 275
 276 static const struct drm_i915_gem_object_ops i915_gem_object_stolen_ops = {
 277         .get_pages = i915_gem_object_get_pages_stolen,
 278         .put_pages = i915_gem_object_put_pages_stolen,
 279 };
 280
 281 static struct drm_i915_gem_object *
 282 _i915_gem_object_create_stolen(struct drm_device *dev,
 283                                struct drm_mm_node *stolen)
 284 {
 285         struct drm_i915_gem_object *obj;
 286
 287         obj = i915_gem_object_alloc(dev);
 288         if (obj == NULL)
 289                 return NULL;
 290
 291         if (drm_gem_private_object_init(dev, &obj->base, stolen->size))
 292                 goto cleanup;
 293
 294         i915_gem_object_init(obj, &i915_gem_object_stolen_ops);
 295
 296         obj->pages = i915_pages_create_for_stolen(dev,
 297                                                   stolen->start, stolen->size);
 298         if (obj->pages == NULL)
 299                 goto cleanup;
 300
 301         obj->has_dma_mapping = true;
 302         i915_gem_object_pin_pages(obj);
 303         obj->stolen = stolen;
 304
 305         obj->base.write_domain = I915_GEM_DOMAIN_GTT;
 306         obj->base.read_domains = I915_GEM_DOMAIN_GTT;
 307         obj->cache_level = I915_CACHE_NONE;
 308
 309         return obj;
 310
 311 cleanup:
 312         i915_gem_object_free(obj);
 313         return NULL;
 314 }
 315
 316 struct drm_i915_gem_object *
 317 i915_gem_object_create_stolen(struct drm_device *dev, u32 size)
 318 {
 319         struct drm_i915_private *dev_priv = dev->dev_private;
 320         struct drm_i915_gem_object *obj;
 321         struct drm_mm_node *stolen;
 322
 323         if (dev_priv->mm.stolen_base == 0)
 324                 return NULL;
 325
 326         DRM_DEBUG_KMS("creating stolen object: size=%x\n", size);
 327         if (size == 0)
 328                 return NULL;
 329
 330         stolen = drm_mm_search_free(&dev_priv->mm.stolen, size, 4096, 0);
 331         if (stolen)
 332                 stolen = drm_mm_get_block(stolen, size, 4096);
 333         if (stolen == NULL)
 334                 return NULL;
 335
 336         obj = _i915_gem_object_create_stolen(dev, stolen);
 337         if (obj)
 338                 return obj;
 339
 340         drm_mm_put_block(stolen);
 341         return NULL;
 342 }
 343
 344 struct drm_i915_gem_object *
 345 i915_gem_object_create_stolen_for_preallocated(struct drm_device *dev,
 346                                                u32 stolen_offset,
 347                                                u32 gtt_offset,
 348                                                u32 size)
 349 {
 350         struct drm_i915_private *dev_priv = dev->dev_private;
 351         struct drm_i915_gem_object *obj;
 352         struct drm_mm_node *stolen;
 353         int ret;
 354
 355         if (dev_priv->mm.stolen_base == 0)
 356                 return NULL;
 357
 358         DRM_DEBUG_KMS("creating preallocated stolen object: stolen_offset=%x, gtt_offset=%x, size=%x\n",
 359                         stolen_offset, gtt_offset, size);
 360
 361         /* KISS and expect everything to be page-aligned */
 362         BUG_ON(stolen_offset & 4095);
 363         BUG_ON(size & 4095);
 364
 365         if (WARN_ON(size == 0))
 366                 return NULL;
 367
 368         stolen = kzalloc(sizeof(*stolen), GFP_KERNEL);
 369         if (!stolen)
 370                 return NULL;
 371
 372         stolen->start = stolen_offset;
 373         stolen->size = size;
 374         ret = drm_mm_reserve_node(&dev_priv->mm.stolen, stolen);
 375         if (ret) {
 376                 DRM_DEBUG_KMS("failed to allocate stolen space\n");
 377                 kfree(stolen);
 378                 return NULL;
 379         }
 380
 381         obj = _i915_gem_object_create_stolen(dev, stolen);
 382         if (obj == NULL) {
 383                 DRM_DEBUG_KMS("failed to allocate stolen object\n");
 384                 drm_mm_put_block(stolen);
 385                 return NULL;
 386         }
 387
 388         /* Some objects just need physical mem from stolen space */
 389         if (gtt_offset == I915_GTT_OFFSET_NONE)
 390                 return obj;
 391
 392         /* To simplify the initialisation sequence between KMS and GTT,
 393          * we allow construction of the stolen object prior to
 394          * setting up the GTT space. The actual reservation will occur
 395          * later.
 396          */
 397         obj->gtt_space.start = gtt_offset;
 398         obj->gtt_space.size = size;
 399         if (drm_mm_initialized(&dev_priv->mm.gtt_space)) {
 400                 ret = drm_mm_reserve_node(&dev_priv->mm.gtt_space,
 401                                           &obj->gtt_space);
 402                 if (ret) {
 403                         DRM_DEBUG_KMS("failed to allocate stolen GTT space\n");
 404                         goto unref_out;
 405                 }
 406         }
 407
 408         obj->has_global_gtt_mapping = 1;
 409
 410         list_add_tail(&obj->global_list, &dev_priv->mm.bound_list);
 411         list_add_tail(&obj->mm_list, &dev_priv->mm.inactive_list);
 412
 413         return obj;
 414
 415 unref_out:
 416         drm_gem_object_unreference(&obj->base);
 417         return NULL;
 418 }
 419
 420 void
 421 i915_gem_object_release_stolen(struct drm_i915_gem_object *obj)
 422 {
 423         if (obj->stolen) {
 424                 drm_mm_put_block(obj->stolen);
 425                 obj->stolen = NULL;
 426         }
 427 }