drm/i915: Introduce ring set_seqno

In preparation for setting per ring initial seqno values
add ring::set_seqno().

Signed-off-by: Mika Kuoppala <mika.kuoppala@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.h b/drivers/gpu/drm/i915/intel_ringbuffer.h
index b4a533e..4a7cd67 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.h
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.h
@@ -79,6 +79,8 @@
 	 */
 	u32		(*get_seqno)(struct intel_ring_buffer *ring,
 				     bool lazy_coherency);
+	void		(*set_seqno)(struct intel_ring_buffer *ring,
+				     u32 seqno);
 	int		(*dispatch_execbuffer)(struct intel_ring_buffer *ring,
 					       u32 offset, u32 length,
 					       unsigned flags);
@@ -166,6 +168,13 @@
 	return ring->status_page.page_addr[reg];
 }
 
+static inline void
+intel_write_status_page(struct intel_ring_buffer *ring,
+			int reg, u32 value)
+{
+	ring->status_page.page_addr[reg] = value;
+}
+
 /**
  * Reads a dword out of the status page, which is written to from the command
  * queue by automatic updates, MI_REPORT_HEAD, MI_STORE_DATA_INDEX, or