drm/radeon: add some additional 6xx/7xx/EG register init

- SMX_SAR_CTL0 needs to be programmed correctly to prevent
problems with memory exports in certain cases.
- VC_ENHANCE needs to be initialized on 6xx/7xx.

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/gpu/drm/radeon/rv770d.h b/drivers/gpu/drm/radeon/rv770d.h
index fdc0898..b0adfc5 100644
--- a/drivers/gpu/drm/radeon/rv770d.h
+++ b/drivers/gpu/drm/radeon/rv770d.h
@@ -211,6 +211,7 @@
 #define	SCRATCH_UMSK					0x8540
 #define	SCRATCH_ADDR					0x8544
 
+#define	SMX_SAR_CTL0					0xA008
 #define	SMX_DC_CTL0					0xA020
 #define		USE_HASH_FUNCTION				(1 << 0)
 #define		CACHE_DEPTH(x)					((x) << 1)
@@ -310,6 +311,8 @@
 #define	TCP_CNTL					0x9610
 #define	TCP_CHAN_STEER					0x9614
 
+#define	VC_ENHANCE					0x9714
+
 #define	VGT_CACHE_INVALIDATION				0x88C4
 #define		CACHE_INVALIDATION(x)				((x)<<0)
 #define			VC_ONLY						0