agp/intel: Fix cache control for Sandybridge

Sandybridge GTT has new cache control bits in PTE, which controls
graphics page cache in LLC or LLC/MLC, so we need to extend the mask
function to respect the new bits.

And set cache control to always LLC only by default on Gen6.

Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Cc: stable@kernel.org
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

drivers/char/agp/intel-agp.c

@@ -12,6 +12,7 @@
 #include <asm/smp.h>
 #include "agp.h"
 #include "intel-agp.h"
+#include <linux/intel-gtt.h>
 
 #include "intel-gtt.c"
 

drivers/char/agp/intel-gtt.c

@@ -49,6 +49,26 @@ static struct gatt_mask intel_i810_masks[] =
 	 .type = INTEL_AGP_CACHED_MEMORY}
 };
 
+#define INTEL_AGP_UNCACHED_MEMORY              0
+#define INTEL_AGP_CACHED_MEMORY_LLC            1
+#define INTEL_AGP_CACHED_MEMORY_LLC_GFDT       2
+#define INTEL_AGP_CACHED_MEMORY_LLC_MLC        3
+#define INTEL_AGP_CACHED_MEMORY_LLC_MLC_GFDT   4
+
+static struct gatt_mask intel_gen6_masks[] =
+{
+	{.mask = I810_PTE_VALID | GEN6_PTE_UNCACHED,
+	 .type = INTEL_AGP_UNCACHED_MEMORY },
+	{.mask = I810_PTE_VALID | GEN6_PTE_LLC,
+         .type = INTEL_AGP_CACHED_MEMORY_LLC },
+	{.mask = I810_PTE_VALID | GEN6_PTE_LLC | GEN6_PTE_GFDT,
+         .type = INTEL_AGP_CACHED_MEMORY_LLC_GFDT },
+	{.mask = I810_PTE_VALID | GEN6_PTE_LLC_MLC,
+         .type = INTEL_AGP_CACHED_MEMORY_LLC_MLC },
+	{.mask = I810_PTE_VALID | GEN6_PTE_LLC_MLC | GEN6_PTE_GFDT,
+         .type = INTEL_AGP_CACHED_MEMORY_LLC_MLC_GFDT },
+};
+
 static struct _intel_private {
 	struct pci_dev *pcidev;	/* device one */
 	u8 __iomem *registers;
@@ -178,13 +198,6 @@ static void intel_agp_insert_sg_entries(struct agp_memory *mem,
 					off_t pg_start, int mask_type)
 {
 	int i, j;
-	u32 cache_bits = 0;
-
-	if (agp_bridge->dev->device == PCI_DEVICE_ID_INTEL_SANDYBRIDGE_HB ||
-	    agp_bridge->dev->device == PCI_DEVICE_ID_INTEL_SANDYBRIDGE_M_HB)
-	{
-		cache_bits = GEN6_PTE_LLC_MLC;
-	}
 
 	for (i = 0, j = pg_start; i < mem->page_count; i++, j++) {
 		writel(agp_bridge->driver->mask_memory(agp_bridge,
@@ -317,6 +330,23 @@ static int intel_i830_type_to_mask_type(struct agp_bridge_data *bridge,
 		return 0;
 }
 
+static int intel_gen6_type_to_mask_type(struct agp_bridge_data *bridge,
+					int type)
+{
+	unsigned int type_mask = type & ~AGP_USER_CACHED_MEMORY_GFDT;
+	unsigned int gfdt = type & AGP_USER_CACHED_MEMORY_GFDT;
+
+	if (type_mask == AGP_USER_UNCACHED_MEMORY)
+		return INTEL_AGP_UNCACHED_MEMORY;
+	else if (type_mask == AGP_USER_CACHED_MEMORY_LLC_MLC)
+		return gfdt ? INTEL_AGP_CACHED_MEMORY_LLC_MLC_GFDT :
+			      INTEL_AGP_CACHED_MEMORY_LLC_MLC;
+	else /* set 'normal'/'cached' to LLC by default */
+		return gfdt ? INTEL_AGP_CACHED_MEMORY_LLC_GFDT :
+			      INTEL_AGP_CACHED_MEMORY_LLC;
+}
+
+
 static int intel_i810_insert_entries(struct agp_memory *mem, off_t pg_start,
 				int type)
 {
@@ -1163,7 +1193,7 @@ static int intel_i915_insert_entries(struct agp_memory *mem, off_t pg_start,
 
 	mask_type = agp_bridge->driver->agp_type_to_mask_type(agp_bridge, type);
 
-	if (mask_type != 0 && mask_type != AGP_PHYS_MEMORY &&
+	if (!IS_SNB && mask_type != 0 && mask_type != AGP_PHYS_MEMORY &&
 	    mask_type != INTEL_AGP_CACHED_MEMORY)
 		goto out_err;
 
@@ -1563,7 +1593,7 @@ static const struct agp_bridge_driver intel_gen6_driver = {
 	.fetch_size		= intel_i9xx_fetch_size,
 	.cleanup		= intel_i915_cleanup,
 	.mask_memory		= intel_gen6_mask_memory,
-	.masks			= intel_i810_masks,
+	.masks			= intel_gen6_masks,
 	.agp_enable		= intel_i810_agp_enable,
 	.cache_flush		= global_cache_flush,
 	.create_gatt_table	= intel_i965_create_gatt_table,
@@ -1576,7 +1606,7 @@ static const struct agp_bridge_driver intel_gen6_driver = {
 	.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,
+	.agp_type_to_mask_type	= intel_gen6_type_to_mask_type,
 	.chipset_flush		= intel_i915_chipset_flush,
 #ifdef USE_PCI_DMA_API
 	.agp_map_page		= intel_agp_map_page,

drivers/gpu/drm/i915/i915_gem.c

@@ -34,6 +34,7 @@
 #include <linux/slab.h>
 #include <linux/swap.h>
 #include <linux/pci.h>
+#include <linux/intel-gtt.h>
 
 static uint32_t i915_gem_get_gtt_alignment(struct drm_gem_object *obj);
 static int i915_gem_object_flush_gpu_write_domain(struct drm_gem_object *obj);

include/linux/intel-gtt.h

@@ -0,0 +1,20 @@
+/*
+ * Common Intel AGPGART and GTT definitions.
+ */
+#ifndef _INTEL_GTT_H
+#define _INTEL_GTT_H
+
+#include <linux/agp_backend.h>
+
+/* This is for Intel only GTT controls.
+ *
+ * Sandybridge: AGP_USER_CACHED_MEMORY default to LLC only
+ */
+
+#define AGP_USER_CACHED_MEMORY_LLC_MLC (AGP_USER_TYPES + 2)
+#define AGP_USER_UNCACHED_MEMORY (AGP_USER_TYPES + 4)
+
+/* flag for GFDT type */
+#define AGP_USER_CACHED_MEMORY_GFDT (1 << 3)
+
+#endif