drm/i915: framebuffer compression for pre-GM45

This patch adds framebuffer compression (good for about ~0.5W power
savings in the best case) support for pre-GM45 chips.  GM45+ have a new,
more flexible FBC scheme that will be added in a separate patch.

FBC can't always be enabled: the compressed buffer must be physically
contiguous and reside in stolen space.  So if you have a large display
and a small amount of stolen memory, you may not be able to take
advantage of FBC.  In some cases, a BIOS setting controls how much
stolen space is available.  Increasing this to 8 or 16M can help.

Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Eric Anholt <eric@anholt.net>

1 files changed, 12 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index f2b8d27aef2a..0344afd841c4 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -48,6 +48,11 @@ enum pipe {
         PIPE_B,
 };
 
+enum plane {
+        PLANE_A = 0,
+        PLANE_B,
+};
+
 #define I915_NUM_PIPE   2
 
 /* Interface history:
@@ -202,6 +207,11 @@ typedef struct drm_i915_private {
 
         struct drm_mm vram;
 
+        unsigned long cfb_size;
+        unsigned long cfb_pitch;
+        int cfb_fence;
+        int cfb_plane;
+
         int irq_enabled;
 
         struct intel_opregion opregion;
@@ -768,6 +778,7 @@ static inline void opregion_enable_asle(struct drm_device *dev) { return; }
 /* modesetting */
 extern void intel_modeset_init(struct drm_device *dev);
 extern void intel_modeset_cleanup(struct drm_device *dev);
+extern void i8xx_disable_fbc(struct drm_device *dev);
 
 /**
  * Lock test for when it's just for synchronization of ring access.
@@ -918,6 +929,7 @@ extern int i915_wait_ring(struct drm_device * dev, int n, const char *caller);
 
 #define HAS_FW_BLC(dev) (IS_I9XX(dev) || IS_G4X(dev) || IS_IGDNG(dev))
 #define HAS_PIPE_CXSR(dev) (IS_G4X(dev) || IS_IGDNG(dev))
+#define I915_HAS_FBC(dev) (IS_I9XX(dev) || IS_I965G(dev))
 
 #define PRIMARY_RINGBUFFER_SIZE         (128*1024)