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, 13 insertions, 4 deletions

diff --git a/src/gallium/drivers/r300/r300_context.c b/src/gallium/drivers/r300/r300_context.c
index e265bdbd3b..552df2b476 100644
--- a/src/gallium/drivers/r300/r300_context.c
+++ b/src/gallium/drivers/r300/r300_context.c
@@ -94,6 +94,9 @@ static void r300_release_referenced_objects(struct r300_context *r300)
         remove_from_list(query);
         FREE(query);
     }
+
+    r300->context.delete_depth_stencil_alpha_state(&r300->context,
+                                                   r300->dsa_decompress_zmask);
 }
 
 static void r300_destroy_context(struct pipe_context* context)
@@ -116,9 +119,6 @@ static void r300_destroy_context(struct pipe_context* context)
     /* XXX: This function assumes r300->query_list was initialized */
     r300_release_referenced_objects(r300);
 
-    if (r300->zmask_mm)
-        r300_hyperz_destroy_mm(r300);
-
     if (r300->cs)
         r300->rws->cs_destroy(r300->cs);
 
@@ -238,7 +238,7 @@ static boolean r300_setup_atoms(struct r300_context* r300)
         if (has_hiz_ram)
             R300_INIT_ATOM(hiz_clear, 0);
         /* zmask clear */
-        R300_INIT_ATOM(zmask_clear, 0);
+        R300_INIT_ATOM(zmask_clear, 4);
     }
     /* ZB (unpipelined), SU. */
     R300_INIT_ATOM(query_start, 4);
@@ -513,6 +513,15 @@ struct pipe_context* r300_create_context(struct pipe_screen* screen,
         r300->dummy_vb = screen->resource_create(screen, &vb);
     }
 
+    {
+        struct pipe_depth_stencil_alpha_state dsa = {};
+        dsa.depth.writemask = 1;
+
+        r300->dsa_decompress_zmask =
+            r300->context.create_depth_stencil_alpha_state(&r300->context,
+                                                           &dsa);
+    }
+
     return &r300->context;
 
  fail: