drm/i915: add frontbuffer tracking to FBC

Kill the blt/render tracking we currently have and use the frontbuffer
tracking infrastructure.

Don't enable things by default yet.

v2: (Rodrigo) Fix small conflict on rebase and typo at subject.
v3: (Paulo) Rebase on RENDER_CS change.
v4: (Paulo) Rebase.
v5: (Paulo) Simplify: flushes don't have origin (Daniel).
            Also rebase due to patch order changes.

Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 2858e01..032459a 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -805,6 +805,8 @@
 	unsigned long uncompressed_size;
 	unsigned threshold;
 	unsigned int fb_id;
+	unsigned int possible_framebuffer_bits;
+	unsigned int busy_bits;
 	struct intel_crtc *crtc;
 	int y;
 
@@ -817,14 +819,6 @@
 	 * possible. */
 	bool enabled;
 
-	/* On gen8 some rings cannont perform fbc clean operation so for now
-	 * we are doing this on SW with mmio.
-	 * This variable works in the opposite information direction
-	 * of ring->fbc_dirty telling software on frontbuffer tracking
-	 * to perform the cache clean on sw side.
-	 */
-	bool need_sw_cache_clean;
-
 	struct intel_fbc_work {
 		struct delayed_work work;
 		struct drm_crtc *crtc;