drm/i915: Add intel implementation of the pageflip ioctl

Acked-by: Jakob Bornecrantz <jakob@vmware.com>
Acked-by: Thomas Hellström <thomas@shipmail.org>
Review-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Jesse "Orange Smoothie" Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Kristian Høgsberg <krh@bitplanet.net>
Signed-off-by: Eric Anholt <eric@anholt.net>
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index d58f7ad..120c77d 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -157,6 +157,8 @@
 #define   MI_OVERLAY_ON		(0x1<<21)
 #define   MI_OVERLAY_OFF	(0x2<<21)
 #define MI_LOAD_SCAN_LINES_INCL MI_INSTR(0x12, 0)
+#define MI_DISPLAY_FLIP		MI_INSTR(0x14, 2)
+#define   MI_DISPLAY_FLIP_PLANE(n) ((n) << 20)
 #define MI_STORE_DWORD_IMM	MI_INSTR(0x20, 1)
 #define   MI_MEM_VIRTUAL	(1 << 22) /* 965+ only */
 #define MI_STORE_DWORD_INDEX	MI_INSTR(0x21, 1)