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,
 119                                            DRM_MM_SEARCH_DEFAULT);
 120         if (!compressed_fb)
 121                 compressed_fb = drm_mm_search_free(&dev_priv->mm.stolen,
 122                                                    size >>= 1, 4096,
 123                                                    DRM_MM_SEARCH_DEFAULT);
 124         if (compressed_fb)
 125                 compressed_fb = drm_mm_get_block(compressed_fb, size, 4096);
 126         if (!compressed_fb)
 127                 goto err;
 128
 129         if (HAS_PCH_SPLIT(dev))
 130                 I915_WRITE(ILK_DPFC_CB_BASE, compressed_fb->start);
 131         else if (IS_GM45(dev)) {
 132                 I915_WRITE(DPFC_CB_BASE, compressed_fb->start);
 133         } else {
 134                 compressed_llb = drm_mm_search_free(&dev_priv->mm.stolen,
 135                                                     4096, 4096,
 136                                                     DRM_MM_SEARCH_DEFAULT);
 137                 if (compressed_llb)
 138                         compressed_llb = drm_mm_get_block(compressed_llb,
 139                                                           4096, 4096);
 140                 if (!compressed_llb)
 141                         goto err_fb;
 142
 143                 dev_priv->fbc.compressed_llb = compressed_llb;
 144
 145                 I915_WRITE(FBC_CFB_BASE,
 146                            dev_priv->mm.stolen_base + compressed_fb->start);
 147                 I915_WRITE(FBC_LL_BASE,
 148                            dev_priv->mm.stolen_base + compressed_llb->start);
 149         }
 150
 151         dev_priv->fbc.compressed_fb = compressed_fb;
 152         dev_priv->fbc.size = size;
 153
 154         DRM_DEBUG_KMS("reserved %d bytes of contiguous stolen space for FBC\n",
 155                       size);
 156
 157         return 0;
 158
 159 err_fb:
 160         drm_mm_put_block(compressed_fb);
 161 err:
 162         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);
 163         return -ENOSPC;
 164 }
 165
 166 int i915_gem_stolen_setup_compression(struct drm_device *dev, int size)
 167 {
 168         struct drm_i915_private *dev_priv = dev->dev_private;
 169
 170         if (!drm_mm_initialized(&dev_priv->mm.stolen))
 171                 return -ENODEV;
 172
 173         if (size < dev_priv->fbc.size)
 174                 return 0;
 175
 176         /* Release any current block */
 177         i915_gem_stolen_cleanup_compression(dev);
 178
 179         return i915_setup_compression(dev, size);
 180 }
 181
 182 void i915_gem_stolen_cleanup_compression(struct drm_device *dev)
 183 {
 184         struct drm_i915_private *dev_priv = dev->dev_private;
 185
 186         if (dev_priv->fbc.size == 0)
 187                 return;
 188
 189         if (dev_priv->fbc.compressed_fb)
 190                 drm_mm_put_block(dev_priv->fbc.compressed_fb);
 191
 192         if (dev_priv->fbc.compressed_llb)
 193                 drm_mm_put_block(dev_priv->fbc.compressed_llb);
 194
 195         dev_priv->fbc.size = 0;
 196 }
 197
 198 void i915_gem_cleanup_stolen(struct drm_device *dev)
 199 {
 200         struct drm_i915_private *dev_priv = dev->dev_private;
 201
 202         if (!drm_mm_initialized(&dev_priv->mm.stolen))
 203                 return;
 204
 205         i915_gem_stolen_cleanup_compression(dev);
 206         drm_mm_takedown(&dev_priv->mm.stolen);
 207 }
 208
 209 int i915_gem_init_stolen(struct drm_device *dev)
 210 {
 211         struct drm_i915_private *dev_priv = dev->dev_private;
 212         int bios_reserved = 0;
 213
 214         dev_priv->mm.stolen_base = i915_stolen_to_physical(dev);
 215         if (dev_priv->mm.stolen_base == 0)
 216                 return 0;
 217
 218         DRM_DEBUG_KMS("found %zd bytes of stolen memory at %08lx\n",
 219                       dev_priv->gtt.stolen_size, dev_priv->mm.stolen_base);
 220
 221         if (IS_VALLEYVIEW(dev))
 222                 bios_reserved = 1024*1024; /* top 1M on VLV/BYT */
 223
 224         if (WARN_ON(bios_reserved > dev_priv->gtt.stolen_size))
 225                 return 0;
 226
 227         /* Basic memrange allocator for stolen space */
 228         drm_mm_init(&dev_priv->mm.stolen, 0, dev_priv->gtt.stolen_size -
 229                     bios_reserved);
 230
 231         return 0;
 232 }
 233
 234 static struct sg_table *
 235 i915_pages_create_for_stolen(struct drm_device *dev,
 236                              u32 offset, u32 size)
 237 {
 238         struct drm_i915_private *dev_priv = dev->dev_private;
 239         struct sg_table *st;
 240         struct scatterlist *sg;
 241
 242         DRM_DEBUG_DRIVER("offset=0x%x, size=%d\n", offset, size);
 243         BUG_ON(offset > dev_priv->gtt.stolen_size - size);
 244
 245         /* We hide that we have no struct page backing our stolen object
 246          * by wrapping the contiguous physical allocation with a fake
 247          * dma mapping in a single scatterlist.
 248          */
 249
 250         st = kmalloc(sizeof(*st), GFP_KERNEL);
 251         if (st == NULL)
 252                 return NULL;
 253
 254         if (sg_alloc_table(st, 1, GFP_KERNEL)) {
 255                 kfree(st);
 256                 return NULL;
 257         }
 258
 259         sg = st->sgl;
 260         sg->offset = offset;
 261         sg->length = size;
 262
 263         sg_dma_address(sg) = (dma_addr_t)dev_priv->mm.stolen_base + offset;
 264         sg_dma_len(sg) = size;
 265
 266         return st;
 267 }
 268
 269 static int i915_gem_object_get_pages_stolen(struct drm_i915_gem_object *obj)
 270 {
 271         BUG();
 272         return -EINVAL;
 273 }
 274
 275 static void i915_gem_object_put_pages_stolen(struct drm_i915_gem_object *obj)
 276 {
 277         /* Should only be called during free */
 278         sg_free_table(obj->pages);
 279         kfree(obj->pages);
 280 }
 281
 282 static const struct drm_i915_gem_object_ops i915_gem_object_stolen_ops = {
 283         .get_pages = i915_gem_object_get_pages_stolen,
 284         .put_pages = i915_gem_object_put_pages_stolen,
 285 };
 286
 287 static struct drm_i915_gem_object *
 288 _i915_gem_object_create_stolen(struct drm_device *dev,
 289                                struct drm_mm_node *stolen)
 290 {
 291         struct drm_i915_gem_object *obj;
 292
 293         obj = i915_gem_object_alloc(dev);
 294         if (obj == NULL)
 295                 return NULL;
 296
 297         drm_gem_private_object_init(dev, &obj->base, stolen->size);
 298         i915_gem_object_init(obj, &i915_gem_object_stolen_ops);
 299
 300         obj->pages = i915_pages_create_for_stolen(dev,
 301                                                   stolen->start, stolen->size);
 302         if (obj->pages == NULL)
 303                 goto cleanup;
 304
 305         obj->has_dma_mapping = true;
 306         i915_gem_object_pin_pages(obj);
 307         obj->stolen = stolen;
 308
 309         obj->base.write_domain = I915_GEM_DOMAIN_GTT;
 310         obj->base.read_domains = I915_GEM_DOMAIN_GTT;
 311         obj->cache_level = I915_CACHE_NONE;
 312
 313         return obj;
 314
 315 cleanup:
 316         i915_gem_object_free(obj);
 317         return NULL;
 318 }
 319
 320 struct drm_i915_gem_object *
 321 i915_gem_object_create_stolen(struct drm_device *dev, u32 size)
 322 {
 323         struct drm_i915_private *dev_priv = dev->dev_private;
 324         struct drm_i915_gem_object *obj;
 325         struct drm_mm_node *stolen;
 326
 327         if (!drm_mm_initialized(&dev_priv->mm.stolen))
 328                 return NULL;
 329
 330         DRM_DEBUG_KMS("creating stolen object: size=%x\n", size);
 331         if (size == 0)
 332                 return NULL;
 333
 334         stolen = drm_mm_search_free(&dev_priv->mm.stolen, size, 4096,
 335                                     DRM_MM_SEARCH_DEFAULT);
 336         if (stolen)
 337                 stolen = drm_mm_get_block(stolen, size, 4096);
 338         if (stolen == NULL)
 339                 return NULL;
 340
 341         obj = _i915_gem_object_create_stolen(dev, stolen);
 342         if (obj)
 343                 return obj;
 344
 345         drm_mm_put_block(stolen);
 346         return NULL;
 347 }
 348
 349 struct drm_i915_gem_object *
 350 i915_gem_object_create_stolen_for_preallocated(struct drm_device *dev,
 351                                                u32 stolen_offset,
 352                                                u32 gtt_offset,
 353                                                u32 size)
 354 {
 355         struct drm_i915_private *dev_priv = dev->dev_private;
 356         struct drm_i915_gem_object *obj;
 357         struct drm_mm_node *stolen;
 358         int ret;
 359
 360         if (!drm_mm_initialized(&dev_priv->mm.stolen))
 361                 return NULL;
 362
 363         DRM_DEBUG_KMS("creating preallocated stolen object: stolen_offset=%x, gtt_offset=%x, size=%x\n",
 364                         stolen_offset, gtt_offset, size);
 365
 366         /* KISS and expect everything to be page-aligned */
 367         BUG_ON(stolen_offset & 4095);
 368         BUG_ON(size & 4095);
 369
 370         if (WARN_ON(size == 0))
 371                 return NULL;
 372
 373         stolen = kzalloc(sizeof(*stolen), GFP_KERNEL);
 374         if (!stolen)
 375                 return NULL;
 376
 377         stolen->start = stolen_offset;
 378         stolen->size = size;
 379         ret = drm_mm_reserve_node(&dev_priv->mm.stolen, stolen);
 380         if (ret) {
 381                 DRM_DEBUG_KMS("failed to allocate stolen space\n");
 382                 kfree(stolen);
 383                 return NULL;
 384         }
 385
 386         obj = _i915_gem_object_create_stolen(dev, stolen);
 387         if (obj == NULL) {
 388                 DRM_DEBUG_KMS("failed to allocate stolen object\n");
 389                 drm_mm_put_block(stolen);
 390                 return NULL;
 391         }
 392
 393         /* Some objects just need physical mem from stolen space */
 394         if (gtt_offset == I915_GTT_OFFSET_NONE)
 395                 return obj;
 396
 397         /* To simplify the initialisation sequence between KMS and GTT,
 398          * we allow construction of the stolen object prior to
 399          * setting up the GTT space. The actual reservation will occur
 400          * later.
 401          */
 402         obj->gtt_space.start = gtt_offset;
 403         obj->gtt_space.size = size;
 404         if (drm_mm_initialized(&dev_priv->mm.gtt_space)) {
 405                 ret = drm_mm_reserve_node(&dev_priv->mm.gtt_space,
 406                                           &obj->gtt_space);
 407                 if (ret) {
 408                         DRM_DEBUG_KMS("failed to allocate stolen GTT space\n");
 409                         goto unref_out;
 410                 }
 411         }
 412
 413         obj->has_global_gtt_mapping = 1;
 414
 415         list_add_tail(&obj->global_list, &dev_priv->mm.bound_list);
 416         list_add_tail(&obj->mm_list, &dev_priv->mm.inactive_list);
 417
 418         return obj;
 419
 420 unref_out:
 421         drm_gem_object_unreference(&obj->base);
 422         return NULL;
 423 }
 424
 425 void
 426 i915_gem_object_release_stolen(struct drm_i915_gem_object *obj)
 427 {
 428         if (obj->stolen) {
 429                 drm_mm_put_block(obj->stolen);
 430                 obj->stolen = NULL;
 431         }
 432 }