drm/i915: Unify unpin_work and mmio_work into flip_work, v2.

Rename intel_unpin_work to intel_flip_work and use it for mmio flips
and unpinning. Use flip_queued_req to hold the wait request in the
mmio case, and the vblank counter from intel_crtc_get_vblank_counter.

MMIO flips get their own path through intel_finish_page_flip_mmio,
handled on vblank. CS page flips go through *_cs.

Changes since v1:
- Clean up destinction between MMIO and CS flips.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1463490484-19540-7-git-send-email-maarten.lankhorst@linux.intel.com
Reviewed-by: Patrik Jakobsson <patrik.jakobsson@linux.intel.com>
diff --git a/drivers/gpu/drm/i915/intel_sprite.c b/drivers/gpu/drm/i915/intel_sprite.c
index 728b924..97b1a54 100644
--- a/drivers/gpu/drm/i915/intel_sprite.c
+++ b/drivers/gpu/drm/i915/intel_sprite.c
@@ -151,13 +151,19 @@
  * re-enables interrupts and verifies the update was actually completed
  * before a vblank using the value of @start_vbl_count.
  */
-void intel_pipe_update_end(struct intel_crtc *crtc)
+void intel_pipe_update_end(struct intel_crtc *crtc, struct intel_flip_work *work)
 {
 	enum pipe pipe = crtc->pipe;
 	int scanline_end = intel_get_crtc_scanline(crtc);
 	u32 end_vbl_count = intel_crtc_get_vblank_counter(crtc);
 	ktime_t end_vbl_time = ktime_get();
 
+	if (work) {
+		work->flip_queued_vblank = end_vbl_count;
+		smp_mb__before_atomic();
+		atomic_set(&work->pending, 1);
+	}
+
 	trace_i915_pipe_update_end(crtc, end_vbl_count, scanline_end);
 
 	local_irq_enable();