intel-agp: add chipset flushing support

This adds support for flushing the chipsets on the 915, 945, 965 and G33
families of Intel chips.

The BIOS doesn't seem to always allocate the BAR on the 965 chipsets
so I have to use pci resource code to create a resource

It adds an export for pcibios_align_resource.

arch/x86/pci/i386.c

···
 		}
 	}
 }
-
+EXPORT_SYMBOL(pcibios_align_resource);
 
 /*
  *  Handle resources of PCI devices.  If the world were perfect, we could

drivers/char/agp/intel-agp.c

···
 #define I915_GMCH_GMS_STOLEN_64M	(0x7 << 4)
 #define G33_GMCH_GMS_STOLEN_128M       (0x8 << 4)
 #define G33_GMCH_GMS_STOLEN_256M       (0x9 << 4)
+#define I915_IFPADDR    0x60
 
 /* Intel 965G registers */
 #define I965_MSAC 0x62
+#define I965_IFPADDR    0x70
 
 /* Intel 7505 registers */
 #define INTEL_I7505_APSIZE	0x74
···
 	 * popup and for the GTT.
 	 */
 	int gtt_entries;			/* i830+ */
+	void __iomem *flush_page;
+	struct resource ifp_resource;
 } intel_private;
 
 static int intel_i810_fetch_size(void)
···
 	return NULL;
 }
 
+static int intel_alloc_chipset_flush_resource(void)
+{
+	int ret;
+	ret = pci_bus_alloc_resource(agp_bridge->dev->bus, &intel_private.ifp_resource, PAGE_SIZE,
+				     PAGE_SIZE, PCIBIOS_MIN_MEM, 0,
+				     pcibios_align_resource, agp_bridge->dev);
+	if (ret != 0)
+		return ret;
+
+	printk("intel priv bus start %08lx\n", intel_private.ifp_resource.start);
+	return 0;
+}
+
+static void intel_i915_setup_chipset_flush(void)
+{
+	int ret;
+	u32 temp;
+
+	pci_read_config_dword(agp_bridge->dev, I915_IFPADDR, &temp);
+	if (!(temp & 0x1)) {
+		intel_alloc_chipset_flush_resource();
+
+		pci_write_config_dword(agp_bridge->dev, I915_IFPADDR, (intel_private.ifp_resource.start & 0xffffffff) | 0x1);
+	} else {
+		temp &= ~1;
+
+		intel_private.ifp_resource.start = temp;
+		intel_private.ifp_resource.end = temp + PAGE_SIZE;
+		ret = request_resource(&iomem_resource, &intel_private.ifp_resource);
+		if (ret) {
+			intel_private.ifp_resource.start = 0;
+			printk("Failed inserting resource into tree\n");
+		}
+	}
+}
+
+static void intel_i965_g33_setup_chipset_flush(void)
+{
+	u32 temp_hi, temp_lo;
+	int ret;
+
+	pci_read_config_dword(agp_bridge->dev, I965_IFPADDR + 4, &temp_hi);
+	pci_read_config_dword(agp_bridge->dev, I965_IFPADDR, &temp_lo);
+
+	if (!(temp_lo & 0x1)) {
+
+		intel_alloc_chipset_flush_resource();
+
+		pci_write_config_dword(agp_bridge->dev, I965_IFPADDR + 4, (intel_private.ifp_resource.start >> 32));
+		pci_write_config_dword(agp_bridge->dev, I965_IFPADDR, (intel_private.ifp_resource.start & 0xffffffff) | 0x1);
+		intel_private.flush_page = ioremap_nocache(intel_private.ifp_resource.start, PAGE_SIZE);
+	} else {
+		u64 l64;
+		
+		temp_lo &= ~0x1;
+		l64 = ((u64)temp_hi << 32) | temp_lo;
+
+		intel_private.ifp_resource.start = l64;
+		intel_private.ifp_resource.end = l64 + PAGE_SIZE;
+		ret = request_resource(&iomem_resource, &intel_private.ifp_resource);
+		if (!ret) {
+			intel_private.ifp_resource.start = 0;
+			printk("Failed inserting resource into tree\n");
+		}
+	}
+}
+
 static int intel_i915_configure(void)
 {
 	struct aper_size_info_fixed *current_size;
···
 	}
 
 	global_cache_flush();
+
+	/* setup a resource for this object */
+	memset(&intel_private.ifp_resource, 0, sizeof(intel_private.ifp_resource));
+
+	intel_private.ifp_resource.name = "Intel Flush Page";
+	intel_private.ifp_resource.flags = IORESOURCE_MEM;
+
+	/* Setup chipset flush for 915 */
+	if (IS_I965 || IS_G33) {
+		intel_i965_g33_setup_chipset_flush();
+	} else {
+		intel_i915_setup_chipset_flush();
+	}
+
+	if (intel_private.ifp_resource.start) {
+		intel_private.flush_page = ioremap_nocache(intel_private.ifp_resource.start, PAGE_SIZE);
+		if (!intel_private.flush_page)
+			printk("unable to ioremap flush  page - no chipset flushing");
+	}
+	
 	return 0;
 }
 
 static void intel_i915_cleanup(void)
 {
+	if (intel_private.flush_page)
+		iounmap(intel_private.flush_page);
 	iounmap(intel_private.gtt);
 	iounmap(intel_private.registers);
+}
+
+static void intel_i915_chipset_flush(struct agp_bridge_data *bridge)
+{
+	if (intel_private.flush_page)
+		writel(1, intel_private.flush_page);
 }
 
 static int intel_i915_insert_entries(struct agp_memory *mem,off_t pg_start,
···
 	.agp_alloc_page		= agp_generic_alloc_page,
 	.agp_destroy_page	= agp_generic_destroy_page,
 	.agp_type_to_mask_type  = intel_i830_type_to_mask_type,
+	.chipset_flush		= intel_i915_chipset_flush,
 };
 
 static const struct agp_bridge_driver intel_i965_driver = {
···
        .agp_alloc_page         = agp_generic_alloc_page,
        .agp_destroy_page       = agp_generic_destroy_page,
        .agp_type_to_mask_type  = intel_i830_type_to_mask_type,
+	.chipset_flush		= intel_i915_chipset_flush,
 };
 
 static const struct agp_bridge_driver intel_7505_driver = {
···
 	.agp_alloc_page         = agp_generic_alloc_page,
 	.agp_destroy_page       = agp_generic_destroy_page,
 	.agp_type_to_mask_type  = intel_i830_type_to_mask_type,
+	.chipset_flush		= intel_i915_chipset_flush,
 };
 
 static int find_gmch(u16 device)