drm/i915: Include a generation number in the device info

To simplify the IS_GEN[234] macros and to enable switching.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 047cd7c..af4a263 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -191,6 +191,7 @@
 };
 
 struct intel_device_info {
+	u8 gen;
 	u8 is_mobile : 1;
 	u8 is_i8xx : 1;
 	u8 is_i85x : 1;
@@ -206,7 +207,6 @@
 	u8 is_broadwater : 1;
 	u8 is_crestline : 1;
 	u8 is_ironlake : 1;
-	u8 is_gen6 : 1;
 	u8 has_fbc : 1;
 	u8 has_rc6 : 1;
 	u8 has_pipe_cxsr : 1;
@@ -1162,7 +1162,6 @@
 #define IS_845G(dev)		((dev)->pci_device == 0x2562)
 #define IS_I85X(dev)		(INTEL_INFO(dev)->is_i85x)
 #define IS_I865G(dev)		((dev)->pci_device == 0x2572)
-#define IS_GEN2(dev)		(INTEL_INFO(dev)->is_i8xx)
 #define IS_I915G(dev)		(INTEL_INFO(dev)->is_i915g)
 #define IS_I915GM(dev)		((dev)->pci_device == 0x2592)
 #define IS_I945G(dev)		((dev)->pci_device == 0x2772)
@@ -1181,27 +1180,13 @@
 #define IS_IRONLAKE_M(dev)	((dev)->pci_device == 0x0046)
 #define IS_IRONLAKE(dev)	(INTEL_INFO(dev)->is_ironlake)
 #define IS_I9XX(dev)		(INTEL_INFO(dev)->is_i9xx)
-#define IS_GEN6(dev)		(INTEL_INFO(dev)->is_gen6)
 #define IS_MOBILE(dev)		(INTEL_INFO(dev)->is_mobile)
 
-#define IS_GEN3(dev)	(IS_I915G(dev) ||			\
-			 IS_I915GM(dev) ||			\
-			 IS_I945G(dev) ||			\
-			 IS_I945GM(dev) ||			\
-			 IS_G33(dev) || \
-			 IS_PINEVIEW(dev))
-#define IS_GEN4(dev)	((dev)->pci_device == 0x2972 ||		\
-			 (dev)->pci_device == 0x2982 ||		\
-			 (dev)->pci_device == 0x2992 ||		\
-			 (dev)->pci_device == 0x29A2 ||		\
-			 (dev)->pci_device == 0x2A02 ||		\
-			 (dev)->pci_device == 0x2A12 ||		\
-			 (dev)->pci_device == 0x2E02 ||		\
-			 (dev)->pci_device == 0x2E12 ||		\
-			 (dev)->pci_device == 0x2E22 ||		\
-			 (dev)->pci_device == 0x2E32 ||		\
-			 (dev)->pci_device == 0x2A42 ||		\
-			 (dev)->pci_device == 0x2E42)
+#define IS_GEN2(dev)	(INTEL_INFO(dev)->gen == 2)
+#define IS_GEN3(dev)	(INTEL_INFO(dev)->gen == 3)
+#define IS_GEN4(dev)	(INTEL_INFO(dev)->gen == 4)
+#define IS_GEN5(dev)	(INTEL_INFO(dev)->gen == 5)
+#define IS_GEN6(dev)	(INTEL_INFO(dev)->gen == 6)
 
 #define HAS_BSD(dev)            (IS_IRONLAKE(dev) || IS_G4X(dev))
 #define I915_NEED_GFX_HWS(dev)	(INTEL_INFO(dev)->need_gfx_hws)