r300g: fix some bugs with zbuffer compression (v4)

This drops the memblock manager for ZMASK. Instead, only one zbuffer can be
compressed at a time. Note that this does not necessarily have to be slower.
When there is a large number of zbuffers, compression might be used more often
than it was before. It's also easier to debug.

How it works:
1) 'clear' turns the compression on.
2) If some other zbuffer is set or the currently-bound zbuffer is used
   for texturing, the driver decompresses it and then turns the compression off.

Notes:
- The ZMASK clear has been refactored, so that only one packet3 is used to clear
  ZMASK.
- The 8x8 compression mode is disabled. I couldn't make it work without issues.
- Also removed driver-specific stuff from u_blitter.

Driver status:
- RV530 and R580 appear to just work (finally).
- RV570 should work, but there may be an issue that we don't correctly
  calculate the number of dwords to clear, resulting in a partially
  uninitialized zbuffer.
- RS690 misrenders as if no ZMASK clear happened. No idea what's going on.
- RV350 may even hardlock. This issue was already present and this patch doesn't
  fix it.

I think we are still missing some hardware info we need to make the zbuffer
compression work fully.

Note that there is also an issue with HiZ, resulting in a sort of blocky
zigzagged corruption around some objects.

1 files changed, 7 insertions, 6 deletions

diff --git a/src/gallium/auxiliary/util/u_blitter.h b/src/gallium/auxiliary/util/u_blitter.h
index 922a8580ac1..47494c94110 100644
--- a/src/gallium/auxiliary/util/u_blitter.h
+++ b/src/gallium/auxiliary/util/u_blitter.h
@@ -55,13 +55,13 @@ struct blitter_context
     * \param y1      A Y coordinate of the top-left corner.
     * \param x2      An X coordinate of the bottom-right corner.
     * \param y2      A Y coordinate of the bottom-right corner.
-    * \param depth  A depth which the rectangle is rendered at.
+    * \param depth   A depth which the rectangle is rendered at.
     *
     * \param type   Semantics of the attributes "attrib".
     *               If type is UTIL_BLITTER_ATTRIB_NONE, ignore them.
     *               If type is UTIL_BLITTER_ATTRIB_COLOR, the attributes
-    *               make up a constant RGBA color, and should go to the COLOR0
-    *               varying slot of a fragment shader.
+    *               make up a constant RGBA color, and should go
+    *               to the GENERIC0 varying slot of a fragment shader.
     *               If type is UTIL_BLITTER_ATTRIB_TEXCOORD, {a1, a2} and
     *               {a3, a4} specify top-left and bottom-right texture
     *               coordinates of the rectangle, respectively, and should go
@@ -141,6 +141,10 @@ void util_blitter_clear(struct blitter_context *blitter,
                         const float *rgba,
                         double depth, unsigned stencil);
 
+void util_blitter_clear_depth_custom(struct blitter_context *blitter,
+                                     unsigned width, unsigned height,
+                                     double depth, void *custom_dsa);
+
 /**
  * Copy a block of pixels from one surface to another.
  *
@@ -200,9 +204,6 @@ void util_blitter_clear_depth_stencil(struct blitter_context *blitter,
                                       unsigned dstx, unsigned dsty,
                                       unsigned width, unsigned height);
 
-void util_blitter_flush_depth_stencil(struct blitter_context *blitter,
-                                      struct pipe_surface *dstsurf);
-
 void util_blitter_custom_depth_stencil(struct blitter_context *blitter,
 				       struct pipe_surface *zsurf,
 				       struct pipe_surface *cbsurf,