2 files changed, 42 insertions, 40 deletions

diff --git a/drivers/gpu/drm/i915/i915_dma.c b/drivers/gpu/drm/i915/i915_dma.c
index ca67338e553..c77fc67a3b8 100644
--- 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 *dev)
 		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(struct drm_device *dev, int size)
 	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(struct drm_device *dev, int size)
 		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(struct drm_device *dev, int size)
 	}
 
 	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_device *dev)
 	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);
 
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 144d37cbcc6..20cd2950495 100644
--- 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;