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, 15 insertions, 0 deletions

diff --git a/src/gallium/auxiliary/util/u_inlines.h b/src/gallium/auxiliary/util/u_inlines.h
index b4870bce981..fc4eb8fdd2e 100644
--- a/src/gallium/auxiliary/util/u_inlines.h
+++ b/src/gallium/auxiliary/util/u_inlines.h
@@ -160,6 +160,21 @@ pipe_surface_init(struct pipe_context *ctx, struct pipe_surface* ps,
    pipe_surface_reset(ctx, ps, pt, level, layer, flags);
 }
 
+/* Return true if the surfaces are equal. */
+static INLINE boolean
+pipe_surface_equal(struct pipe_surface *s1, struct pipe_surface *s2)
+{
+   return s1->texture == s2->texture &&
+          s1->format == s2->format &&
+          (s1->texture->target != PIPE_BUFFER ||
+           (s1->u.buf.first_element == s2->u.buf.first_element &&
+            s1->u.buf.last_element == s2->u.buf.last_element)) &&
+          (s1->texture->target == PIPE_BUFFER ||
+           (s1->u.tex.level == s2->u.tex.level &&
+            s1->u.tex.first_layer == s2->u.tex.first_layer &&
+            s1->u.tex.last_layer == s2->u.tex.last_layer));
+}
+
 /*
  * Convenience wrappers for screen buffer functions.
  */