panfrost: Z16 depth buffer support

Only for MFBD GPUs as on t720 it causes some dEQP tests to fail.

Reviewed-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/7201>

.gitlab-ci/traces-panfrost.yml

@@ -57,7 +57,7 @@ traces:
   - path: 0ad/0ad.trace
     expectations:
       - device: gl-panfrost-t860
-        checksum: b906fb7b106ff287a1d49614015b6653
+        checksum: e159a06f423998ea7fcc0107f0e62f15
   - path: glmark2/buffer-columns=200:interleave=false:update-dispersion=0.9:update-fraction=0.5:update-method=map.rdc
     expectations:
       - device: gl-panfrost-t860
@@ -169,7 +169,7 @@ traces:
   - path: glmark2/terrain.rdc
     expectations:
       - device: gl-panfrost-t860
-        checksum: 2e625ceb1a7fdc3cdefae57297999492
+        checksum: 3ad257e1db7ad3e5dfd88fb1091ddeae
   - path: glmark2/texture-texture-filter=linear.rdc
     expectations:
       - device: gl-panfrost-t860

src/gallium/drivers/panfrost/pan_mfbd.c

@@ -401,6 +401,9 @@ panfrost_mfbd_zs_crc_ext_set_bufs(struct panfrost_batch *batch,
         }
 
         switch (zs_surf->format) {
+        case PIPE_FORMAT_Z16_UNORM:
+                ext->zs_write_format = MALI_ZS_FORMAT_D16;
+                break;
         case PIPE_FORMAT_Z24_UNORM_S8_UINT:
                 ext->zs_write_format = MALI_ZS_FORMAT_D24S8;
                 break;

src/gallium/drivers/panfrost/pan_screen.c

@@ -468,6 +468,10 @@ panfrost_is_format_supported( struct pipe_screen *screen,
         if (is_bifrost && sample_count > 1)
                 return false;
 
+        /* Z16 causes dEQP failures on t720 */
+        if (format == PIPE_FORMAT_Z16_UNORM && dev->quirks & MIDGARD_SFBD)
+                return false;
+
         /* Don't confuse poorly written apps (workaround dEQP bug) that expect
          * more alpha than they ask for */
 

src/gallium/drivers/panfrost/pan_sfbd.c

@@ -158,6 +158,9 @@ panfrost_sfbd_set_zsbuf(
         fb->zs_writeback.base = rsrc->bo->ptr.gpu + rsrc->slices[level].offset;
         fb->zs_writeback.row_stride = rsrc->slices[level].stride * 16;
         switch (surf->format) {
+        case PIPE_FORMAT_Z16_UNORM:
+                fb->zs_format = MALI_ZS_FORMAT_D16;
+                break;
         case PIPE_FORMAT_Z24_UNORM_S8_UINT:
                 fb->zs_format = MALI_ZS_FORMAT_D24S8;
                 break;

src/panfrost/lib/pan_format.c

@@ -155,6 +155,7 @@ struct panfrost_format panfrost_pipe_format_table[PIPE_FORMAT_COUNT] = {
 
         [PIPE_FORMAT_R3G3B2_UNORM] 		= { MALI_RGB332_UNORM, _VT },
 
+        [PIPE_FORMAT_Z16_UNORM]                 = { MALI_R16_UNORM, _TZ },
         [PIPE_FORMAT_Z24_UNORM_S8_UINT]		= { MALI_Z24X8_UNORM, _TZ },
         [PIPE_FORMAT_Z24X8_UNORM]		= { MALI_Z24X8_UNORM, _TZ },
         [PIPE_FORMAT_Z32_FLOAT]		        = { MALI_R32F, _TZ },