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 (INTEL_INFO(dev)->gen >= 6) { 66 /* Read Base Data of Stolen Memory Register (BDSM) directly. 67 * Note that there is also a MCHBAR miror at 0x1080c0 or 68 * we could use device 2:0x5c instead. 69 */ 70 pci_read_config_dword(pdev, 0xB0, &base); 71 base &= ~4095; /* lower bits used for locking register */ 72 } else if (INTEL_INFO(dev)->gen > 3 || IS_G33(dev)) { 73 /* Read Graphics Base of Stolen Memory directly */ 74 pci_read_config_dword(pdev, 0xA4, &base); 75 #if 0 76 } else if (IS_GEN3(dev)) { 77 u8 val; 78 /* Stolen is immediately below Top of Low Usable DRAM */ 79 pci_read_config_byte(pdev, 0x9c, &val); 80 base = val >> 3 << 27; 81 base -= dev_priv->mm.gtt->stolen_size; 82 } else { 83 /* Stolen is immediately above Top of Memory */ 84 base = max_low_pfn_mapped << PAGE_SHIFT; 85 #endif 86 } 87 88 return base; 89 } 90 91 static int i915_setup_compression(struct drm_device *dev, int size) 92 { 93 struct drm_i915_private *dev_priv = dev->dev_private; 94 struct drm_mm_node *compressed_fb, *compressed_llb = NULL; 95 96 /* Try to over-allocate to reduce reallocations and fragmentation */ 97 compressed_fb = drm_mm_search_free(&dev_priv->mm.stolen, 98 size <<= 1, 4096, 0); 99 if (!compressed_fb) 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_get_block(compressed_fb, size, 4096); 104 if (!compressed_fb) 105 goto err; 106 107 if (HAS_PCH_SPLIT(dev)) 108 I915_WRITE(ILK_DPFC_CB_BASE, compressed_fb->start); 109 else if (IS_GM45(dev)) { 110 I915_WRITE(DPFC_CB_BASE, compressed_fb->start); 111 } else { 112 compressed_llb = drm_mm_search_free(&dev_priv->mm.stolen, 113 4096, 4096, 0); 114 if (compressed_llb) 115 compressed_llb = drm_mm_get_block(compressed_llb, 116 4096, 4096); 117 if (!compressed_llb) 118 goto err_fb; 119 120 dev_priv->compressed_llb = compressed_llb; 121 122 I915_WRITE(FBC_CFB_BASE, 123 dev_priv->mm.stolen_base + compressed_fb->start); 124 I915_WRITE(FBC_LL_BASE, 125 dev_priv->mm.stolen_base + compressed_llb->start); 126 } 127 128 dev_priv->compressed_fb = compressed_fb; 129 dev_priv->cfb_size = size; 130 131 DRM_DEBUG_KMS("reserved %d bytes of contiguous stolen space for FBC\n", 132 size); 133 134 return 0; 135 136 err_fb: 137 drm_mm_put_block(compressed_fb); 138 err: 139 return -ENOSPC; 140 } 141 142 int i915_gem_stolen_setup_compression(struct drm_device *dev, int size) 143 { 144 struct drm_i915_private *dev_priv = dev->dev_private; 145 146 if (dev_priv->mm.stolen_base == 0) 147 return -ENODEV; 148 149 if (size < dev_priv->cfb_size) 150 return 0; 151 152 /* Release any current block */ 153 i915_gem_stolen_cleanup_compression(dev); 154 155 return i915_setup_compression(dev, size); 156 } 157 158 void i915_gem_stolen_cleanup_compression(struct drm_device *dev) 159 { 160 struct drm_i915_private *dev_priv = dev->dev_private; 161 162 if (dev_priv->cfb_size == 0) 163 return; 164 165 if (dev_priv->compressed_fb) 166 drm_mm_put_block(dev_priv->compressed_fb); 167 168 if (dev_priv->compressed_llb) 169 drm_mm_put_block(dev_priv->compressed_llb); 170 171 dev_priv->cfb_size = 0; 172 } 173 174 void i915_gem_cleanup_stolen(struct drm_device *dev) 175 { 176 struct drm_i915_private *dev_priv = dev->dev_private; 177 178 i915_gem_stolen_cleanup_compression(dev); 179 drm_mm_takedown(&dev_priv->mm.stolen); 180 } 181 182 int i915_gem_init_stolen(struct drm_device *dev) 183 { 184 struct drm_i915_private *dev_priv = dev->dev_private; 185 186 dev_priv->mm.stolen_base = i915_stolen_to_physical(dev); 187 if (dev_priv->mm.stolen_base == 0) 188 return 0; 189 190 DRM_DEBUG_KMS("found %zd bytes of stolen memory at %08lx\n", 191 dev_priv->gtt.stolen_size, dev_priv->mm.stolen_base); 192 193 /* Basic memrange allocator for stolen space */ 194 drm_mm_init(&dev_priv->mm.stolen, 0, dev_priv->gtt.stolen_size); 195 196 return 0; 197 } 198