| From: Chris Wilson <chris@chris-wilson.co.uk> |
| Date: Thu, 15 Nov 2012 11:32:18 +0000 |
| Subject: drm/i915: Fix detection of base of stolen memory |
| |
| commit e12a2d53ae45a69aea499b64f75e7222cca0f12f upstream. |
| |
| The routine to query the base of stolen memory was using the wrong |
| registers and the wrong encodings on virtually every platform. |
| |
| It was not until the G33 refresh, that a PCI config register was |
| introduced that explicitly said where the stolen memory was. Prior to |
| 865G there was not even a register that said where the end of usable |
| low memory was and where the stolen memory began (or ended depending |
| upon chipset). Before then, one has to look at the BIOS memory maps to |
| find the Top of Memory. Alas that is not exported by arch/x86 and so we |
| have to resort to disabling stolen memory on gen2 for the time being. |
| |
| Then SandyBridge enlarged the PCI register to a full 32-bits and change |
| the encoding of the address, so even though we happened to be querying |
| the right register, we read the wrong bits and ended up using address 0 |
| for our stolen data, i.e. notably FBC. |
| |
| Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> |
| Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch> |
| [bwh: Backported to 3.2: adjust filename, context] |
| Signed-off-by: Ben Hutchings <ben@decadent.org.uk> |
| --- |
| drivers/gpu/drm/i915/i915_drv.h | 1 + |
| drivers/gpu/drm/i915/i915_gem_stolen.c | 81 ++++++++++++++++---------------- |
| 2 files changed, 42 insertions(+), 40 deletions(-) |
| |
| --- a/drivers/gpu/drm/i915/i915_drv.h |
| +++ b/drivers/gpu/drm/i915/i915_drv.h |
| @@ -581,6 +581,7 @@ typedef struct drm_i915_private { |
| unsigned long gtt_start; |
| unsigned long gtt_mappable_end; |
| unsigned long gtt_end; |
| + unsigned long stolen_base; /* limited to low memory (32-bit) */ |
| |
| struct io_mapping *gtt_mapping; |
| int gtt_mtrr; |
| --- a/drivers/gpu/drm/i915/i915_dma.c |
| +++ b/drivers/gpu/drm/i915/i915_dma.c |
| @@ -1007,56 +1007,50 @@ intel_teardown_mchbar(struct drm_device |
| release_resource(&dev_priv->mch_res); |
| } |
| |
| -#define PTE_ADDRESS_MASK 0xfffff000 |
| -#define PTE_ADDRESS_MASK_HIGH 0x000000f0 /* i915+ */ |
| -#define PTE_MAPPING_TYPE_UNCACHED (0 << 1) |
| -#define PTE_MAPPING_TYPE_DCACHE (1 << 1) /* i830 only */ |
| -#define PTE_MAPPING_TYPE_CACHED (3 << 1) |
| -#define PTE_MAPPING_TYPE_MASK (3 << 1) |
| -#define PTE_VALID (1 << 0) |
| - |
| -/** |
| - * i915_stolen_to_phys - take an offset into stolen memory and turn it into |
| - * a physical one |
| - * @dev: drm device |
| - * @offset: address to translate |
| - * |
| - * Some chip functions require allocations from stolen space and need the |
| - * physical address of the memory in question. |
| - */ |
| -static unsigned long i915_stolen_to_phys(struct drm_device *dev, u32 offset) |
| +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; |
| u32 base; |
| |
| -#if 0 |
| /* On the machines I have tested the Graphics Base of Stolen Memory |
| - * is unreliable, so 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. |
| + * 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. |
| + * |
| + * 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. |
| */ |
| - if (INTEL_INFO(dev)->gen > 3 || IS_G33(dev)) { |
| - /* top 32bits are reserved = 0 */ |
| + base = 0; |
| + 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 { |
| - /* XXX presume 8xx is the same as i915 */ |
| - pci_bus_read_config_dword(pdev->bus, 2, 0x5C, &base); |
| - } |
| -#else |
| - if (INTEL_INFO(dev)->gen > 3 || IS_G33(dev)) { |
| - u16 val; |
| - pci_read_config_word(pdev, 0xb0, &val); |
| - base = val >> 4 << 20; |
| - } else { |
| +#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; |
| + base -= dev_priv->mm.gtt->stolen_size; |
| + } else { |
| + /* Stolen is immediately above Top of Memory */ |
| + base = max_low_pfn_mapped << PAGE_SHIFT; |
| #endif |
| + } |
| |
| - return base + offset; |
| + return base; |
| } |
| |
| static void i915_warn_stolen(struct drm_device *dev) |
| @@ -1081,7 +1075,7 @@ static void i915_setup_compression(struc |
| if (!compressed_fb) |
| goto err; |
| |
| - cfb_base = i915_stolen_to_phys(dev, compressed_fb->start); |
| + cfb_base = dev_priv->mm.stolen_base + compressed_fb->start; |
| if (!cfb_base) |
| goto err_fb; |
| |
| @@ -1094,7 +1088,7 @@ static void i915_setup_compression(struc |
| if (!compressed_llb) |
| goto err_fb; |
| |
| - ll_base = i915_stolen_to_phys(dev, compressed_llb->start); |
| + ll_base = dev_priv->mm.stolen_base + compressed_llb->start; |
| if (!ll_base) |
| goto err_llb; |
| } |
| @@ -1113,7 +1107,7 @@ static void i915_setup_compression(struc |
| } |
| |
| DRM_DEBUG_KMS("FBC base 0x%08lx, ll base 0x%08lx, size %dM\n", |
| - cfb_base, ll_base, size >> 20); |
| + (long)cfb_base, (long)ll_base, size >> 20); |
| return; |
| |
| err_llb: |
| @@ -1187,6 +1181,13 @@ static int i915_load_gem_init(struct drm |
| gtt_size = dev_priv->mm.gtt->gtt_total_entries << PAGE_SHIFT; |
| mappable_size = dev_priv->mm.gtt->gtt_mappable_entries << PAGE_SHIFT; |
| |
| + dev_priv->mm.stolen_base = i915_stolen_to_physical(dev); |
| + if (dev_priv->mm.stolen_base == 0) |
| + return 0; |
| + |
| + DRM_DEBUG_KMS("found %d bytes of stolen memory at %08lx\n", |
| + dev_priv->mm.gtt->stolen_size, dev_priv->mm.stolen_base); |
| + |
| /* Basic memrange allocator for stolen space */ |
| drm_mm_init(&dev_priv->mm.stolen, 0, prealloc_size); |
| |