diff --git a/drivers/gpu/drm/i915/i915_gem_stolen.c b/drivers/gpu/drm/i915/i915_gem_stolen.c index 9a1896c86dcd..837cf534f47a 100644 --- a/drivers/gpu/drm/i915/i915_gem_stolen.c +++ b/drivers/gpu/drm/i915/i915_gem_stolen.c @@ -45,45 +45,27 @@ static unsigned long i915_stolen_to_physical(struct drm_device *dev) { struct drm_i915_private *dev_priv = dev->dev_private; - struct pci_dev *pdev = dev_priv->bridge_dev; struct resource *r; u32 base; - /* On the machines I have tested the Graphics Base of Stolen Memory - * is unreliable, so on those compute the base by subtracting the - * stolen memory from the Top of Low Usable DRAM which is where the - * BIOS places the graphics stolen memory. + /* Almost universally we can find the Graphics Base of Stolen Memory + * at offset 0x5c in the igfx configuration space. On a few (desktop) + * machines this is also mirrored in the bridge device at different + * locations, or in the MCHBAR. On gen2, the layout is again slightly + * different with the Graphics Segment immediately following Top of + * Memory (or Top of Usable DRAM). Note it appears that TOUD is only + * reported by 865g, so we just use the top of memory as determined + * by the e820 probe. * - * On gen2, the layout is slightly different with the Graphics Segment - * immediately following Top of Memory (or Top of Usable DRAM). Note - * it appears that TOUD is only reported by 865g, so we just use the - * top of memory as determined by the e820 probe. - * - * XXX gen2 requires an unavailable symbol and 945gm fails with - * its value of TOLUD. + * XXX However gen2 requires an unavailable symbol. */ base = 0; - if (IS_VALLEYVIEW(dev)) { + if (INTEL_INFO(dev)->gen >= 3) { + /* Read Graphics Base of Stolen Memory directly */ pci_read_config_dword(dev->pdev, 0x5c, &base); base &= ~((1<<20) - 1); - } else if (INTEL_INFO(dev)->gen >= 6) { - /* Read Base Data of Stolen Memory Register (BDSM) directly. - * Note that there is also a MCHBAR miror at 0x1080c0 or - * we could use device 2:0x5c instead. - */ - pci_read_config_dword(pdev, 0xB0, &base); - base &= ~4095; /* lower bits used for locking register */ - } else if (INTEL_INFO(dev)->gen > 3 || IS_G33(dev)) { - /* Read Graphics Base of Stolen Memory directly */ - pci_read_config_dword(pdev, 0xA4, &base); + } else { /* GEN2 */ #if 0 - } else if (IS_GEN3(dev)) { - u8 val; - /* Stolen is immediately below Top of Low Usable DRAM */ - pci_read_config_byte(pdev, 0x9c, &val); - base = val >> 3 << 27; - base -= dev_priv->mm.gtt->stolen_size; - } else { /* Stolen is immediately above Top of Memory */ base = max_low_pfn_mapped << PAGE_SHIFT; #endif