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 "drmP.h"
  30 #include "drm.h"
  31 #include "i915_drm.h"
  32 #include "i915_drv.h"
  33
  34 /*
  35  * The BIOS typically reserves some of the system's memory for the exclusive
  36  * use of the integrated graphics. This memory is no longer available for
  37  * use by the OS and so the user finds that his system has less memory
  38  * available than he put in. We refer to this memory as stolen.
  39  *
  40  * The BIOS will allocate its framebuffer from the stolen memory. Our
  41  * goal is try to reuse that object for our own fbcon which must always
  42  * be available for panics. Anything else we can reuse the stolen memory
  43  * for is a boon.
  44  */
  45
  46 #define PTE_ADDRESS_MASK                0xfffff000
  47 #define PTE_ADDRESS_MASK_HIGH           0x000000f0 /* i915+ */
  48 #define PTE_MAPPING_TYPE_UNCACHED       (0 << 1)
  49 #define PTE_MAPPING_TYPE_DCACHE         (1 << 1) /* i830 only */
  50 #define PTE_MAPPING_TYPE_CACHED         (3 << 1)
  51 #define PTE_MAPPING_TYPE_MASK           (3 << 1)
  52 #define PTE_VALID                       (1 << 0)
  53
  54 /**
  55  * i915_stolen_to_phys - take an offset into stolen memory and turn it into
  56  *                       a physical one
  57  * @dev: drm device
  58  * @offset: address to translate
  59  *
  60  * Some chip functions require allocations from stolen space and need the
  61  * physical address of the memory in question.
  62  */
  63 static unsigned long i915_stolen_to_phys(struct drm_device *dev, u32 offset)
  64 {
  65         struct drm_i915_private *dev_priv = dev->dev_private;
  66         struct pci_dev *pdev = dev_priv->bridge_dev;
  67         u32 base;
  68
  69 #if 0
  70         /* On the machines I have tested the Graphics Base of Stolen Memory
  71          * is unreliable, so compute the base by subtracting the stolen memory
  72          * from the Top of Low Usable DRAM which is where the BIOS places
  73          * the graphics stolen memory.
  74          */
  75         if (INTEL_INFO(dev)->gen > 3 || IS_G33(dev)) {
  76                 /* top 32bits are reserved = 0 */
  77                 pci_read_config_dword(pdev, 0xA4, &base);
  78         } else {
  79                 /* XXX presume 8xx is the same as i915 */
  80                 pci_bus_read_config_dword(pdev->bus, 2, 0x5C, &base);
  81         }
  82 #else
  83         if (INTEL_INFO(dev)->gen > 3 || IS_G33(dev)) {
  84                 u16 val;
  85                 pci_read_config_word(pdev, 0xb0, &val);
  86                 base = val >> 4 << 20;
  87         } else {
  88                 u8 val;
  89                 pci_read_config_byte(pdev, 0x9c, &val);
  90                 base = val >> 3 << 27;
  91         }
  92         base -= dev_priv->mm.gtt->stolen_size;
  93 #endif
  94
  95         return base + offset;
  96 }
  97
  98 static void i915_warn_stolen(struct drm_device *dev)
  99 {
 100         DRM_INFO("not enough stolen space for compressed buffer, disabling\n");
 101         DRM_INFO("hint: you may be able to increase stolen memory size in the BIOS to avoid this\n");
 102 }
 103
 104 static void i915_setup_compression(struct drm_device *dev, int size)
 105 {
 106         struct drm_i915_private *dev_priv = dev->dev_private;
 107         struct drm_mm_node *compressed_fb, *uninitialized_var(compressed_llb);
 108         unsigned long cfb_base;
 109         unsigned long ll_base = 0;
 110
 111         /* Just in case the BIOS is doing something questionable. */
 112         intel_disable_fbc(dev);
 113
 114         compressed_fb = drm_mm_search_free(&dev_priv->mm.stolen, size, 4096, 0);
 115         if (compressed_fb)
 116                 compressed_fb = drm_mm_get_block(compressed_fb, size, 4096);
 117         if (!compressed_fb)
 118                 goto err;
 119
 120         cfb_base = i915_stolen_to_phys(dev, compressed_fb->start);
 121         if (!cfb_base)
 122                 goto err_fb;
 123
 124         if (!(IS_GM45(dev) || HAS_PCH_SPLIT(dev))) {
 125                 compressed_llb = drm_mm_search_free(&dev_priv->mm.stolen,
 126                                                     4096, 4096, 0);
 127                 if (compressed_llb)
 128                         compressed_llb = drm_mm_get_block(compressed_llb,
 129                                                           4096, 4096);
 130                 if (!compressed_llb)
 131                         goto err_fb;
 132
 133                 ll_base = i915_stolen_to_phys(dev, compressed_llb->start);
 134                 if (!ll_base)
 135                         goto err_llb;
 136         }
 137
 138         dev_priv->cfb_size = size;
 139
 140         dev_priv->compressed_fb = compressed_fb;
 141         if (HAS_PCH_SPLIT(dev))
 142                 I915_WRITE(ILK_DPFC_CB_BASE, compressed_fb->start);
 143         else if (IS_GM45(dev)) {
 144                 I915_WRITE(DPFC_CB_BASE, compressed_fb->start);
 145         } else {
 146                 I915_WRITE(FBC_CFB_BASE, cfb_base);
 147                 I915_WRITE(FBC_LL_BASE, ll_base);
 148                 dev_priv->compressed_llb = compressed_llb;
 149         }
 150
 151         DRM_DEBUG_KMS("FBC base 0x%08lx, ll base 0x%08lx, size %dM\n",
 152                       cfb_base, ll_base, size >> 20);
 153         return;
 154
 155 err_llb:
 156         drm_mm_put_block(compressed_llb);
 157 err_fb:
 158         drm_mm_put_block(compressed_fb);
 159 err:
 160         dev_priv->no_fbc_reason = FBC_STOLEN_TOO_SMALL;
 161         i915_warn_stolen(dev);
 162 }
 163
 164 static void i915_cleanup_compression(struct drm_device *dev)
 165 {
 166         struct drm_i915_private *dev_priv = dev->dev_private;
 167
 168         drm_mm_put_block(dev_priv->compressed_fb);
 169         if (dev_priv->compressed_llb)
 170                 drm_mm_put_block(dev_priv->compressed_llb);
 171 }
 172
 173 void i915_gem_cleanup_stolen(struct drm_device *dev)
 174 {
 175         if (I915_HAS_FBC(dev) && i915_powersave)
 176                 i915_cleanup_compression(dev);
 177 }
 178
 179 int i915_gem_init_stolen(struct drm_device *dev)
 180 {
 181         struct drm_i915_private *dev_priv = dev->dev_private;
 182         unsigned long prealloc_size = dev_priv->mm.gtt->stolen_size;
 183
 184         /* Basic memrange allocator for stolen space */
 185         drm_mm_init(&dev_priv->mm.stolen, 0, prealloc_size);
 186
 187         /* Try to set up FBC with a reasonable compressed buffer size */
 188         if (I915_HAS_FBC(dev) && i915_powersave) {
 189                 int cfb_size;
 190
 191                 /* Leave 1M for line length buffer & misc. */
 192
 193                 /* Try to get a 32M buffer... */
 194                 if (prealloc_size > (36*1024*1024))
 195                         cfb_size = 32*1024*1024;
 196                 else /* fall back to 7/8 of the stolen space */
 197                         cfb_size = prealloc_size * 7 / 8;
 198                 i915_setup_compression(dev, cfb_size);
 199         }
 200
 201         return 0;
 202 }