drm/i915: add a LLC feature flag in device description

LLC is not SNB/IVB-specific, so we should check for it in a more generic
way.

Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Eric Anholt <eric@anholt.net>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Signed-off-by: Eugeni Dodonov <eugeni.dodonov@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/i915_debugfs.c

@@ -83,6 +83,7 @@ static int i915_capabilities(struct seq_file *m, void *data)
 	B(supports_tv);
 	B(has_bsd_ring);
 	B(has_blt_ring);
+	B(has_llc);
 #undef B
 
 	return 0;

drivers/gpu/drm/i915/i915_dma.c

@@ -784,6 +784,9 @@ static int i915_getparam(struct drm_device *dev, void *data,
 	case I915_PARAM_HAS_GEN7_SOL_RESET:
 		value = 1;
 		break;
+	case I915_PARAM_HAS_LLC:
+		value = HAS_LLC(dev);
+		break;
 	default:
 		DRM_DEBUG_DRIVER("Unknown parameter %d\n",
 				 param->param);

drivers/gpu/drm/i915/i915_drv.c

@@ -214,6 +214,7 @@ static const struct intel_device_info intel_sandybridge_d_info = {
 	.need_gfx_hws = 1, .has_hotplug = 1,
 	.has_bsd_ring = 1,
 	.has_blt_ring = 1,
+	.has_llc = 1,
 };
 
 static const struct intel_device_info intel_sandybridge_m_info = {
@@ -222,6 +223,7 @@ static const struct intel_device_info intel_sandybridge_m_info = {
 	.has_fbc = 1,
 	.has_bsd_ring = 1,
 	.has_blt_ring = 1,
+	.has_llc = 1,
 };
 
 static const struct intel_device_info intel_ivybridge_d_info = {
@@ -229,6 +231,7 @@ static const struct intel_device_info intel_ivybridge_d_info = {
 	.need_gfx_hws = 1, .has_hotplug = 1,
 	.has_bsd_ring = 1,
 	.has_blt_ring = 1,
+	.has_llc = 1,
 };
 
 static const struct intel_device_info intel_ivybridge_m_info = {
@@ -237,6 +240,7 @@ static const struct intel_device_info intel_ivybridge_m_info = {
 	.has_fbc = 0,	/* FBC is not enabled on Ivybridge mobile yet */
 	.has_bsd_ring = 1,
 	.has_blt_ring = 1,
+	.has_llc = 1,
 };
 
 static const struct pci_device_id pciidlist[] = {		/* aka */

drivers/gpu/drm/i915/i915_drv.h

@@ -255,6 +255,7 @@ struct intel_device_info {
 	u8 supports_tv:1;
 	u8 has_bsd_ring:1;
 	u8 has_blt_ring:1;
+	u8 has_llc:1;
 };
 
 enum no_fbc_reason {
@@ -969,6 +970,7 @@ struct drm_i915_file_private {
 
 #define HAS_BSD(dev)            (INTEL_INFO(dev)->has_bsd_ring)
 #define HAS_BLT(dev)            (INTEL_INFO(dev)->has_blt_ring)
+#define HAS_LLC(dev)            (INTEL_INFO(dev)->has_llc)
 #define I915_NEED_GFX_HWS(dev)	(INTEL_INFO(dev)->need_gfx_hws)
 
 #define HAS_OVERLAY(dev)		(INTEL_INFO(dev)->has_overlay)

drivers/gpu/drm/i915/i915_gem.c

@@ -3619,8 +3619,8 @@ struct drm_i915_gem_object *i915_gem_alloc_object(struct drm_device *dev,
 	obj->base.write_domain = I915_GEM_DOMAIN_CPU;
 	obj->base.read_domains = I915_GEM_DOMAIN_CPU;
 
-	if (IS_GEN6(dev) || IS_GEN7(dev)) {
-		/* On Gen6, we can have the GPU use the LLC (the CPU
+	if (HAS_LLC(dev)) {
+		/* On some devices, we can have the GPU use the LLC (the CPU
 		 * cache) for about a 10% performance improvement
 		 * compared to uncached.  Graphics requests other than
 		 * display scanout are coherent with the CPU in

include/drm/i915_drm.h

@@ -296,6 +296,7 @@ typedef struct drm_i915_irq_wait {
 #define I915_PARAM_HAS_EXEC_CONSTANTS	 14
 #define I915_PARAM_HAS_RELAXED_DELTA	 15
 #define I915_PARAM_HAS_GEN7_SOL_RESET	 16
+#define I915_PARAM_HAS_LLC     	 17
 
 typedef struct drm_i915_getparam {
 	int param;