drm/radeon/cayman: setup hdp to invalidate and flush when asked

On cayman we need to set the bit to cause HDP flushes to invalidate the
HDP cache also.
Reviewed-by: NAlex Deucher <alexdeucher@gmail.com>
cc: stable@kernel.org
Signed-off-by: NDave Airlie <airlied@redhat.com>

drivers/gpu/drm/radeon/ni.c

@@ -931,6 +931,10 @@ static void cayman_gpu_init(struct radeon_device *rdev)
 	WREG32(CB_PERF_CTR3_SEL_0, 0);
 	WREG32(CB_PERF_CTR3_SEL_1, 0);
 
+	tmp = RREG32(HDP_MISC_CNTL);
+	tmp |= HDP_FLUSH_INVALIDATE_CACHE;
+	WREG32(HDP_MISC_CNTL, tmp);
+
 	hdp_host_path_cntl = RREG32(HDP_HOST_PATH_CNTL);
 	WREG32(HDP_HOST_PATH_CNTL, hdp_host_path_cntl);
 

drivers/gpu/drm/radeon/nid.h

@@ -136,6 +136,8 @@
 #define	HDP_NONSURFACE_INFO				0x2C08
 #define	HDP_NONSURFACE_SIZE				0x2C0C
 #define HDP_ADDR_CONFIG  				0x2F48
+#define HDP_MISC_CNTL					0x2F4C
+#define 	HDP_FLUSH_INVALIDATE_CACHE			(1 << 0)
 
 #define	CC_SYS_RB_BACKEND_DISABLE			0x3F88
 #define	GC_USER_SYS_RB_BACKEND_DISABLE			0x3F8C