[Mesa-dev] [RFC] i965: Restructure CCS disable

[Topi Pohjolainen]

From: Ben Widawsky <ben at bwidawsk.net>

Make the code only disable CCS when it has to, unlike before where it
disabled CCS and enabled it when it could. This is much more inline with
how it should work in a few patches, where we have fewer restrictions as
to when we disable CCS.

v2: Change CCS disabling to an assertion in layout creation (Topi)

v3: Also switch the logic in intel_update_winsys_renderbuffer_miptree().
    Previously it assumed that the aux disable is set by default and it
    needs to be lifted when CCS is supported. Now it has to actually
    check if CCS is not supported and to set the disable flag.

Signed-off-by: Ben Widawsky <ben at bwidawsk.net>
---
 src/mesa/drivers/dri/i965/intel_mipmap_tree.c | 19 +++++++++++--------
 1 file changed, 11 insertions(+), 8 deletions(-)

diff --git a/src/mesa/drivers/dri/i965/intel_mipmap_tree.c b/src/mesa/drivers/dri/i965/intel_mipmap_tree.c
index 78ab3ad..cfeb257 100644
--- a/src/mesa/drivers/dri/i965/intel_mipmap_tree.c
+++ b/src/mesa/drivers/dri/i965/intel_mipmap_tree.c
@@ -329,7 +329,6 @@ intel_miptree_create_layout(struct brw_context *brw,
    mt->logical_depth0 = depth0;
    mt->aux_disable = (layout_flags & MIPTREE_LAYOUT_DISABLE_AUX) != 0 ?
       INTEL_AUX_DISABLE_ALL : INTEL_AUX_DISABLE_NONE;
-   mt->aux_disable |= INTEL_AUX_DISABLE_CCS;
    mt->is_scanout = (layout_flags & MIPTREE_LAYOUT_FOR_SCANOUT) != 0;
    exec_list_make_empty(&mt->hiz_map);
    exec_list_make_empty(&mt->color_resolve_map);
@@ -522,6 +521,8 @@ intel_miptree_create_layout(struct brw_context *brw,
    } else if (brw->gen >= 9 && num_samples > 1) {
       layout_flags |= MIPTREE_LAYOUT_FORCE_HALIGN16;
    } else {
+      mt->aux_disable |= INTEL_AUX_DISABLE_CCS;
+
       const UNUSED bool is_lossless_compressed_aux =
          brw->gen >= 9 && num_samples == 1 &&
          mt->format == MESA_FORMAT_R_UINT32;
@@ -739,7 +740,6 @@ intel_miptree_create(struct brw_context *brw,
     */
    if (intel_tiling_supports_non_msrt_mcs(brw, mt->tiling) &&
        intel_miptree_supports_non_msrt_fast_clear(brw, mt)) {
-      mt->aux_disable &= ~INTEL_AUX_DISABLE_CCS;
       assert(brw->gen < 8 || mt->halign == 16 || num_samples <= 1);
 
       /* On Gen9+ clients are not currently capable of consuming compressed
@@ -753,8 +753,11 @@ intel_miptree_create(struct brw_context *brw,
          intel_miptree_supports_lossless_compressed(brw, mt);
 
       if (is_lossless_compressed) {
+         assert((mt->aux_disable & INTEL_AUX_DISABLE_CCS) == 0);
          intel_miptree_alloc_non_msrt_mcs(brw, mt, is_lossless_compressed);
       }
+   } else {
+      mt->aux_disable |= INTEL_AUX_DISABLE_CCS;
    }
 
    return mt;
@@ -846,7 +849,7 @@ create_ccs_buf_for_image(struct brw_context *intel,
    mt->mcs_buf->qpitch = isl_surf_get_array_pitch_sa_rows(&temp_ccs_surf);
 
    intel_miptree_init_mcs(intel, mt, 0);
-   mt->aux_disable &= ~INTEL_AUX_DISABLE_CCS;
+   assert(!(mt->aux_disable & INTEL_AUX_DISABLE_CCS));
    mt->msaa_layout = INTEL_MSAA_LAYOUT_CMS;
 
    return true;
@@ -941,14 +944,14 @@ intel_update_winsys_renderbuffer_miptree(struct brw_context *intel,
    if (!singlesample_mt)
       goto fail;
 
-   /* If this miptree is capable of supporting fast color clears, set
-    * mcs_state appropriately to ensure that fast clears will occur.
+   /* If this miptree is not capable of supporting fast color clears, flag
+    * mcs allocation disabled.
     * Allocation of the MCS miptree will be deferred until the first fast
     * clear actually occurs.
     */
-   if (intel_tiling_supports_non_msrt_mcs(intel, singlesample_mt->tiling) &&
-       intel_miptree_supports_non_msrt_fast_clear(intel, singlesample_mt)) {
-      singlesample_mt->aux_disable &= ~INTEL_AUX_DISABLE_CCS;
+   if (!intel_tiling_supports_non_msrt_mcs(intel, singlesample_mt->tiling) ||
+       !intel_miptree_supports_non_msrt_fast_clear(intel, singlesample_mt)) {
+      singlesample_mt->aux_disable |= INTEL_AUX_DISABLE_CCS;
    }
 
    if (num_samples == 0) {
-- 
2.9.3