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>

4 files changed, 62 insertions, 10 deletions

diff --git a/drivers/char/agp/intel-agp.c b/drivers/char/agp/intel-agp.c
index 710af89b176d..74461d177baf 100644
--- a/drivers/char/agp/intel-agp.c
+++ b/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"
 
diff --git a/drivers/char/agp/intel-gtt.c b/drivers/char/agp/intel-gtt.c
index 7f35854d33a3..64b10551a3f8 100644
--- a/drivers/char/agp/intel-gtt.c
+++ b/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,
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 748c26340c35..16fca1d1799a 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/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);
diff --git a/include/linux/intel-gtt.h b/include/linux/intel-gtt.h
new file mode 100644
index 000000000000..1d19ab2afa39
--- /dev/null
+++ b/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