agp/intel: Support the extended physical addressing bits on Sandybridge.

Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
[anholt: Split this patch out of a larger patch for Sandybridge fixes]
Signed-off-by: Eric Anholt <eric@anholt.net>
diff --git a/drivers/char/agp/intel-gtt.c b/drivers/char/agp/intel-gtt.c
index f97122a..2b1a0e9 100644
--- a/drivers/char/agp/intel-gtt.c
+++ b/drivers/char/agp/intel-gtt.c
@@ -1315,6 +1315,16 @@
 	return addr | bridge->driver->masks[type].mask;
 }
 
+static unsigned long intel_gen6_mask_memory(struct agp_bridge_data *bridge,
+					    dma_addr_t addr, int type)
+{
+	/* Shift high bits down */
+	addr |= (addr >> 28) & 0xff;
+
+	/* Type checking must be done elsewhere */
+	return addr | bridge->driver->masks[type].mask;
+}
+
 static void intel_i965_get_gtt_range(int *gtt_offset, int *gtt_size)
 {
 	u16 snb_gmch_ctl;
@@ -1528,6 +1538,39 @@
 #endif
 };
 
+static const struct agp_bridge_driver intel_gen6_driver = {
+	.owner			= THIS_MODULE,
+	.aperture_sizes		= intel_i830_sizes,
+	.size_type		= FIXED_APER_SIZE,
+	.num_aperture_sizes	= 4,
+	.needs_scratch_page	= true,
+	.configure		= intel_i9xx_configure,
+	.fetch_size		= intel_i9xx_fetch_size,
+	.cleanup		= intel_i915_cleanup,
+	.mask_memory		= intel_gen6_mask_memory,
+	.masks			= intel_i810_masks,
+	.agp_enable		= intel_i810_agp_enable,
+	.cache_flush		= global_cache_flush,
+	.create_gatt_table	= intel_i965_create_gatt_table,
+	.free_gatt_table	= intel_i830_free_gatt_table,
+	.insert_memory		= intel_i915_insert_entries,
+	.remove_memory		= intel_i915_remove_entries,
+	.alloc_by_type		= intel_i830_alloc_by_type,
+	.free_by_type		= intel_i810_free_by_type,
+	.agp_alloc_page		= agp_generic_alloc_page,
+	.agp_alloc_pages        = agp_generic_alloc_pages,
+	.agp_destroy_page	= agp_generic_destroy_page,
+	.agp_destroy_pages      = agp_generic_destroy_pages,
+	.agp_type_to_mask_type	= intel_i830_type_to_mask_type,
+	.chipset_flush		= intel_i915_chipset_flush,
+#ifdef USE_PCI_DMA_API
+	.agp_map_page		= intel_agp_map_page,
+	.agp_unmap_page		= intel_agp_unmap_page,
+	.agp_map_memory		= intel_agp_map_memory,
+	.agp_unmap_memory	= intel_agp_unmap_memory,
+#endif
+};
+
 static const struct agp_bridge_driver intel_g33_driver = {
 	.owner			= THIS_MODULE,
 	.aperture_sizes		= intel_i830_sizes,