1 files changed, 58 insertions, 52 deletions

diff --git a/drivers/char/agp/intel-agp.c b/drivers/char/agp/intel-agp.c
index 029d7f697567..ccb8018b831f 100644
--- a/drivers/char/agp/intel-agp.c
+++ b/drivers/char/agp/intel-agp.c
@@ -382,6 +382,11 @@ static struct _intel_i830_private {
 	struct pci_dev *i830_dev;		/* device one */
 	volatile u8 __iomem *registers;
 	volatile u32 __iomem *gtt;		/* I915G */
+	/* gtt_entries is the number of gtt entries that are already mapped
+	 * to stolen memory.  Stolen memory is larger than the memory mapped
+	 * through gtt_entries, as it includes some reserved space for the BIOS
+	 * popup and for the GTT.
+	 */
 	int gtt_entries;
 } intel_i830_private;
 
@@ -392,14 +397,41 @@ static void intel_i830_init_gtt_entries(void)
 	u8 rdct;
 	int local = 0;
 	static const int ddt[4] = { 0, 16, 32, 64 };
-	int size;
+	int size; /* reserved space (in kb) at the top of stolen memory */
 
 	pci_read_config_word(agp_bridge->dev,I830_GMCH_CTRL,&gmch_ctrl);
 
-	/* We obtain the size of the GTT, which is also stored (for some
-	 * reason) at the top of stolen memory. Then we add 4KB to that
-	 * for the video BIOS popup, which is also stored in there. */
-	size = agp_bridge->driver->fetch_size() + 4;
+	if (IS_I965) {
+		u32 pgetbl_ctl;
+
+		pci_read_config_dword(agp_bridge->dev, I810_PGETBL_CTL,
+				      &pgetbl_ctl);
+		/* The 965 has a field telling us the size of the GTT,
+		 * which may be larger than what is necessary to map the
+		 * aperture.
+		 */
+		switch (pgetbl_ctl & I965_PGETBL_SIZE_MASK) {
+		case I965_PGETBL_SIZE_128KB:
+			size = 128;
+			break;
+		case I965_PGETBL_SIZE_256KB:
+			size = 256;
+			break;
+		case I965_PGETBL_SIZE_512KB:
+			size = 512;
+			break;
+		default:
+			printk(KERN_INFO PFX "Unknown page table size, "
+			       "assuming 512KB\n");
+			size = 512;
+		}
+		size += 4; /* add in BIOS popup space */
+	} else {
+		/* On previous hardware, the GTT size was just what was
+		 * required to map the aperture.
+		 */
+		size = agp_bridge->driver->fetch_size() + 4;
+	}
 
 	if (agp_bridge->dev->device == PCI_DEVICE_ID_INTEL_82830_HB ||
 	    agp_bridge->dev->device == PCI_DEVICE_ID_INTEL_82845G_HB) {
@@ -765,22 +797,27 @@ static int intel_i915_remove_entries(struct agp_memory *mem,off_t pg_start,
 	return 0;
 }
 
-static int intel_i915_fetch_size(void)
+/* Return the aperture size by just checking the resource length.  The effect
+ * described in the spec of the MSAC registers is just changing of the
+ * resource size.
+ */
+static int intel_i9xx_fetch_size(void)
 {
-	struct aper_size_info_fixed *values;
-	u32 temp, offset;
+	int num_sizes = sizeof(intel_i830_sizes) / sizeof(*intel_i830_sizes);
+	int aper_size; /* size in megabytes */
+	int i;
 
-#define I915_256MB_ADDRESS_MASK (1<<27)
+	aper_size = pci_resource_len(intel_i830_private.i830_dev, 2) / MB(1);
 
-	values = A_SIZE_FIX(agp_bridge->driver->aperture_sizes);
+	for (i = 0; i < num_sizes; i++) {
+		if (aper_size == intel_i830_sizes[i].size) {
+			agp_bridge->current_size = intel_i830_sizes + i;
+			agp_bridge->previous_size = agp_bridge->current_size;
+			return aper_size;
+		}
+	}
 
-	pci_read_config_dword(intel_i830_private.i830_dev, I915_GMADDR, &temp);
-	if (temp & I915_256MB_ADDRESS_MASK)
-		offset = 0;	/* 128MB aperture */
-	else
-		offset = 2;	/* 256MB aperture */
-	agp_bridge->previous_size = agp_bridge->current_size = (void *)(values + offset);
-	return values[offset].size;
+	return 0;
 }
 
 /* The intel i915 automatically initializes the agp aperture during POST.
@@ -843,40 +880,9 @@ static unsigned long intel_i965_mask_memory(struct agp_bridge_data *bridge,
 	return addr | bridge->driver->masks[type].mask;
 }
 
-static int intel_i965_fetch_size(void)
-{
-       struct aper_size_info_fixed *values;
-       u32 offset = 0;
-       u8 temp;
-
-#define I965_512MB_ADDRESS_MASK (3<<1)
-
-       values = A_SIZE_FIX(agp_bridge->driver->aperture_sizes);
-
-       pci_read_config_byte(intel_i830_private.i830_dev, I965_MSAC, &temp);
-       temp &= I965_512MB_ADDRESS_MASK;
-       switch (temp) {
-       case 0x00:
-               offset = 0; /* 128MB */
-               break;
-       case 0x06:
-               offset = 3; /* 512MB */
-               break;
-       default:
-       case 0x02:
-               offset = 2; /* 256MB */
-               break;
-       }
-
-       agp_bridge->previous_size = agp_bridge->current_size = (void *)(values + offset);
-
-	/* The i965 GTT is always sized as if it had a 512kB aperture size */
-	return 512;
-}
-
 /* The intel i965 automatically initializes the agp aperture during POST.
-+ * Use the memory already set aside for in the GTT.
-+ */
+ * Use the memory already set aside for in the GTT.
+ */
 static int intel_i965_create_gatt_table(struct agp_bridge_data *bridge)
 {
        int page_order;
@@ -1596,7 +1602,7 @@ static struct agp_bridge_driver intel_915_driver = {
 	.num_aperture_sizes	= 4,
 	.needs_scratch_page	= TRUE,
 	.configure		= intel_i915_configure,
-	.fetch_size		= intel_i915_fetch_size,
+	.fetch_size		= intel_i9xx_fetch_size,
 	.cleanup		= intel_i915_cleanup,
 	.tlb_flush		= intel_i810_tlbflush,
 	.mask_memory		= intel_i810_mask_memory,
@@ -1620,7 +1626,7 @@ static struct agp_bridge_driver intel_i965_driver = {
        .num_aperture_sizes     = 4,
        .needs_scratch_page     = TRUE,
        .configure              = intel_i915_configure,
-       .fetch_size             = intel_i965_fetch_size,
+       .fetch_size             = intel_i9xx_fetch_size,
        .cleanup                = intel_i915_cleanup,
        .tlb_flush              = intel_i810_tlbflush,
        .mask_memory            = intel_i965_mask_memory,