drm/i915: use new macros to access the ring head register

Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.h b/drivers/gpu/drm/i915/intel_ringbuffer.h
index 9d0ae5a..af09eaa 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.h
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.h
@@ -11,6 +11,8 @@
 #define I915_WRITE_TAIL(ring, val) I915_WRITE(RING_TAIL(ring->mmio_base), val)
 #define I915_READ_START(ring) I915_READ(RING_START(ring->mmio_base))
 #define I915_WRITE_START(ring, val) I915_WRITE(RING_START(ring->mmio_base), val)
+#define I915_READ_HEAD(ring) I915_READ(RING_HEAD(ring->mmio_base))
+#define I915_WRITE_HEAD(ring, val) I915_WRITE(RING_HEAD(ring->mmio_base), val)
 
 struct drm_i915_gem_execbuffer2;
 struct  intel_ring_buffer {
@@ -21,7 +23,6 @@
 	} id;
 	struct		ring_regs {
 			u32 ctl;
-			u32 head;
 	} regs;
 	u32		mmio_base;
 	unsigned long	size;
@@ -48,8 +49,6 @@
 	int		(*init)(struct drm_device *dev,
 			struct intel_ring_buffer *ring);
 
-	unsigned int	(*get_head)(struct drm_device *dev,
-			struct intel_ring_buffer *ring);
 	void		(*set_tail)(struct drm_device *dev,
 				    struct intel_ring_buffer *ring,
 				    u32 value);