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         u32 base;
  50
  51         /* On the machines I have tested the Graphics Base of Stolen Memory
  52          * is unreliable, so on those compute the base by subtracting the
  53          * stolen memory from the Top of Low Usable DRAM which is where the
  54          * BIOS places the graphics stolen memory.
  55          *
  56          * On gen2, the layout is slightly different with the Graphics Segment
  57          * immediately following Top of Memory (or Top of Usable DRAM). Note
  58          * it appears that TOUD is only reported by 865g, so we just use the
  59          * top of memory as determined by the e820 probe.
  60          *
  61          * XXX gen2 requires an unavailable symbol and 945gm fails with
  62          * its value of TOLUD.
  63          */
  64         base = 0;
  65         if (IS_VALLEYVIEW(dev)) {
  66                 pci_read_config_dword(dev->pdev, 0x5c, &base);
  67                 base &= ~((1<<20) - 1);
  68         } else if (INTEL_INFO(dev)->gen >= 6) {
  69                 /* Read Base Data of Stolen Memory Register (BDSM) directly.
  70                  * Note that there is also a MCHBAR miror at 0x1080c0 or
  71                  * we could use device 2:0x5c instead.
  72                 */
  73                 pci_read_config_dword(pdev, 0xB0, &base);
  74                 base &= ~4095; /* lower bits used for locking register */
  75         } else if (INTEL_INFO(dev)->gen > 3 || IS_G33(dev)) {
  76                 /* Read Graphics Base of Stolen Memory directly */
  77                 pci_read_config_dword(pdev, 0xA4, &base);
  78 #if 0
  79         } else if (IS_GEN3(dev)) {
  80                 u8 val;
  81                 /* Stolen is immediately below Top of Low Usable DRAM */
  82                 pci_read_config_byte(pdev, 0x9c, &val);
  83                 base = val >> 3 << 27;
  84                 base -= dev_priv->mm.gtt->stolen_size;
  85         } else {
  86                 /* Stolen is immediately above Top of Memory */
  87                 base = max_low_pfn_mapped << PAGE_SHIFT;
  88 #endif
  89         }
  90
  91         return base;
  92 }
  93
  94 static int i915_setup_compression(struct drm_device *dev, int size)
  95 {
  96         struct drm_i915_private *dev_priv = dev->dev_private;
  97         struct drm_mm_node *compressed_fb, *uninitialized_var(compressed_llb);
  98
  99         /* Try to over-allocate to reduce reallocations and fragmentation */
 100         compressed_fb = drm_mm_search_free(&dev_priv->mm.stolen,
 101                                            size <<= 1, 4096, 0);
 102         if (!compressed_fb)
 103                 compressed_fb = drm_mm_search_free(&dev_priv->mm.stolen,
 104                                                    size >>= 1, 4096, 0);
 105         if (compressed_fb)
 106                 compressed_fb = drm_mm_get_block(compressed_fb, size, 4096);
 107         if (!compressed_fb)
 108                 goto err;
 109
 110         if (HAS_PCH_SPLIT(dev))
 111                 I915_WRITE(ILK_DPFC_CB_BASE, compressed_fb->start);
 112         else if (IS_GM45(dev)) {
 113                 I915_WRITE(DPFC_CB_BASE, compressed_fb->start);
 114         } else {
 115                 compressed_llb = drm_mm_search_free(&dev_priv->mm.stolen,
 116                                                     4096, 4096, 0);
 117                 if (compressed_llb)
 118                         compressed_llb = drm_mm_get_block(compressed_llb,
 119                                                           4096, 4096);
 120                 if (!compressed_llb)
 121                         goto err_fb;
 122
 123                 dev_priv->compressed_llb = compressed_llb;
 124
 125                 I915_WRITE(FBC_CFB_BASE,
 126                            dev_priv->mm.stolen_base + compressed_fb->start);
 127                 I915_WRITE(FBC_LL_BASE,
 128                            dev_priv->mm.stolen_base + compressed_llb->start);
 129         }
 130
 131         dev_priv->compressed_fb = compressed_fb;
 132         dev_priv->cfb_size = size;
 133
 134         DRM_DEBUG_KMS("reserved %d bytes of contiguous stolen space for FBC\n",
 135                       size);
 136
 137         return 0;
 138
 139 err_fb:
 140         drm_mm_put_block(compressed_fb);
 141 err:
 142         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);
 143         return -ENOSPC;
 144 }
 145
 146 int i915_gem_stolen_setup_compression(struct drm_device *dev, int size)
 147 {
 148         struct drm_i915_private *dev_priv = dev->dev_private;
 149
 150         if (dev_priv->mm.stolen_base == 0)
 151                 return -ENODEV;
 152
 153         if (size < dev_priv->cfb_size)
 154                 return 0;
 155
 156         /* Release any current block */
 157         i915_gem_stolen_cleanup_compression(dev);
 158
 159         return i915_setup_compression(dev, size);
 160 }
 161
 162 void i915_gem_stolen_cleanup_compression(struct drm_device *dev)
 163 {
 164         struct drm_i915_private *dev_priv = dev->dev_private;
 165
 166         if (dev_priv->cfb_size == 0)
 167                 return;
 168
 169         if (dev_priv->compressed_fb)
 170                 drm_mm_put_block(dev_priv->compressed_fb);
 171
 172         if (dev_priv->compressed_llb)
 173                 drm_mm_put_block(dev_priv->compressed_llb);
 174
 175         dev_priv->cfb_size = 0;
 176 }
 177
 178 void i915_gem_cleanup_stolen(struct drm_device *dev)
 179 {
 180         struct drm_i915_private *dev_priv = dev->dev_private;
 181
 182         i915_gem_stolen_cleanup_compression(dev);
 183         drm_mm_takedown(&dev_priv->mm.stolen);
 184 }
 185
 186 int i915_gem_init_stolen(struct drm_device *dev)
 187 {
 188         struct drm_i915_private *dev_priv = dev->dev_private;
 189         int bios_reserved = 0;
 190
 191         dev_priv->mm.stolen_base = i915_stolen_to_physical(dev);
 192         if (dev_priv->mm.stolen_base == 0)
 193                 return 0;
 194
 195         DRM_DEBUG_KMS("found %zd bytes of stolen memory at %08lx\n",
 196                       dev_priv->gtt.stolen_size, dev_priv->mm.stolen_base);
 197
 198         if (IS_VALLEYVIEW(dev))
 199                 bios_reserved = 1024*1024; /* top 1M on VLV/BYT */
 200
 201         /* Basic memrange allocator for stolen space */
 202         drm_mm_init(&dev_priv->mm.stolen, 0, dev_priv->gtt.stolen_size -
 203                     bios_reserved);
 204
 205         return 0;
 206 }
 207
 208 static struct sg_table *
 209 i915_pages_create_for_stolen(struct drm_device *dev,
 210                              u32 offset, u32 size)
 211 {
 212         struct drm_i915_private *dev_priv = dev->dev_private;
 213         struct sg_table *st;
 214         struct scatterlist *sg;
 215
 216         DRM_DEBUG_DRIVER("offset=0x%x, size=%d\n", offset, size);
 217         BUG_ON(offset > dev_priv->gtt.stolen_size - size);
 218
 219         /* We hide that we have no struct page backing our stolen object
 220          * by wrapping the contiguous physical allocation with a fake
 221          * dma mapping in a single scatterlist.
 222          */
 223
 224         st = kmalloc(sizeof(*st), GFP_KERNEL);
 225         if (st == NULL)
 226                 return NULL;
 227
 228         if (sg_alloc_table(st, 1, GFP_KERNEL)) {
 229                 kfree(st);
 230                 return NULL;
 231         }
 232
 233         sg = st->sgl;
 234         sg->offset = offset;
 235         sg->length = size;
 236
 237         sg_dma_address(sg) = (dma_addr_t)dev_priv->mm.stolen_base + offset;
 238         sg_dma_len(sg) = size;
 239
 240         return st;
 241 }
 242
 243 static int i915_gem_object_get_pages_stolen(struct drm_i915_gem_object *obj)
 244 {
 245         BUG();
 246         return -EINVAL;
 247 }
 248
 249 static void i915_gem_object_put_pages_stolen(struct drm_i915_gem_object *obj)
 250 {
 251         /* Should only be called during free */
 252         sg_free_table(obj->pages);
 253         kfree(obj->pages);
 254 }
 255
 256 static const struct drm_i915_gem_object_ops i915_gem_object_stolen_ops = {
 257         .get_pages = i915_gem_object_get_pages_stolen,
 258         .put_pages = i915_gem_object_put_pages_stolen,
 259 };
 260
 261 static struct drm_i915_gem_object *
 262 _i915_gem_object_create_stolen(struct drm_device *dev,
 263                                struct drm_mm_node *stolen)
 264 {
 265         struct drm_i915_gem_object *obj;
 266
 267         obj = i915_gem_object_alloc(dev);
 268         if (obj == NULL)
 269                 return NULL;
 270
 271         if (drm_gem_private_object_init(dev, &obj->base, stolen->size))
 272                 goto cleanup;
 273
 274         i915_gem_object_init(obj, &i915_gem_object_stolen_ops);
 275
 276         obj->pages = i915_pages_create_for_stolen(dev,
 277                                                   stolen->start, stolen->size);
 278         if (obj->pages == NULL)
 279                 goto cleanup;
 280
 281         obj->has_dma_mapping = true;
 282         i915_gem_object_pin_pages(obj);
 283         obj->stolen = stolen;
 284
 285         obj->base.write_domain = I915_GEM_DOMAIN_GTT;
 286         obj->base.read_domains = I915_GEM_DOMAIN_GTT;
 287         obj->cache_level = I915_CACHE_NONE;
 288
 289         return obj;
 290
 291 cleanup:
 292         i915_gem_object_free(obj);
 293         return NULL;
 294 }
 295
 296 struct drm_i915_gem_object *
 297 i915_gem_object_create_stolen(struct drm_device *dev, u32 size)
 298 {
 299         struct drm_i915_private *dev_priv = dev->dev_private;
 300         struct drm_i915_gem_object *obj;
 301         struct drm_mm_node *stolen;
 302
 303         if (dev_priv->mm.stolen_base == 0)
 304                 return NULL;
 305
 306         DRM_DEBUG_KMS("creating stolen object: size=%x\n", size);
 307         if (size == 0)
 308                 return NULL;
 309
 310         stolen = drm_mm_search_free(&dev_priv->mm.stolen, size, 4096, 0);
 311         if (stolen)
 312                 stolen = drm_mm_get_block(stolen, size, 4096);
 313         if (stolen == NULL)
 314                 return NULL;
 315
 316         obj = _i915_gem_object_create_stolen(dev, stolen);
 317         if (obj)
 318                 return obj;
 319
 320         drm_mm_put_block(stolen);
 321         return NULL;
 322 }
 323
 324 struct drm_i915_gem_object *
 325 i915_gem_object_create_stolen_for_preallocated(struct drm_device *dev,
 326                                                u32 stolen_offset,
 327                                                u32 gtt_offset,
 328                                                u32 size)
 329 {
 330         struct drm_i915_private *dev_priv = dev->dev_private;
 331         struct drm_i915_gem_object *obj;
 332         struct drm_mm_node *stolen;
 333
 334         if (dev_priv->mm.stolen_base == 0)
 335                 return NULL;
 336
 337         DRM_DEBUG_KMS("creating preallocated stolen object: stolen_offset=%x, gtt_offset=%x, size=%x\n",
 338                         stolen_offset, gtt_offset, size);
 339
 340         /* KISS and expect everything to be page-aligned */
 341         BUG_ON(stolen_offset & 4095);
 342         BUG_ON(size & 4095);
 343
 344         if (WARN_ON(size == 0))
 345                 return NULL;
 346
 347         stolen = drm_mm_create_block(&dev_priv->mm.stolen,
 348                                      stolen_offset, size,
 349                                      false);
 350         if (stolen == NULL) {
 351                 DRM_DEBUG_KMS("failed to allocate stolen space\n");
 352                 return NULL;
 353         }
 354
 355         obj = _i915_gem_object_create_stolen(dev, stolen);
 356         if (obj == NULL) {
 357                 DRM_DEBUG_KMS("failed to allocate stolen object\n");
 358                 drm_mm_put_block(stolen);
 359                 return NULL;
 360         }
 361
 362         /* Some objects just need physical mem from stolen space */
 363         if (gtt_offset == -1)
 364                 return obj;
 365
 366         /* To simplify the initialisation sequence between KMS and GTT,
 367          * we allow construction of the stolen object prior to
 368          * setting up the GTT space. The actual reservation will occur
 369          * later.
 370          */
 371         if (drm_mm_initialized(&dev_priv->mm.gtt_space)) {
 372                 obj->gtt_space = drm_mm_create_block(&dev_priv->mm.gtt_space,
 373                                                      gtt_offset, size,
 374                                                      false);
 375                 if (obj->gtt_space == NULL) {
 376                         DRM_DEBUG_KMS("failed to allocate stolen GTT space\n");
 377                         drm_gem_object_unreference(&obj->base);
 378                         return NULL;
 379                 }
 380         } else
 381                 obj->gtt_space = I915_GTT_RESERVED;
 382
 383         obj->gtt_offset = gtt_offset;
 384         obj->has_global_gtt_mapping = 1;
 385
 386         list_add_tail(&obj->global_list, &dev_priv->mm.bound_list);
 387         list_add_tail(&obj->mm_list, &dev_priv->mm.inactive_list);
 388
 389         return obj;
 390 }
 391
 392 void
 393 i915_gem_object_release_stolen(struct drm_i915_gem_object *obj)
 394 {
 395         if (obj->stolen) {
 396                 drm_mm_put_block(obj->stolen);
 397                 obj->stolen = NULL;
 398         }
 399 }