i965/blorp: Update the fast clear value buffer.

On Gen10, whenever we do a fast clear, blorp will update the clear color
state buffer for us, as long as we set the clear color address
correctly.

However, on a hiz clear, if the surface is already on the fast clear
state we skip the actual fast clear operation and, before gen10, only
updated the miptree. On gen10+ we need to update the clear value state
buffer too, since blorp will not be doing a fast clear and updating it
for us.

v4:
 - do not use clear_value_size in the for loop
 - Get the address of the clear color from the aux buffer or the
 clear_color_bo, depending on which one is available.
 - let core blorp update the clear color, but also update it when we
 skip a fast clear depth.

v5: Better subject (Jordan).
v6: Remove outdated comment (Jason).

Signed-off-by: Rafael Antognolli <[email protected]>
Reviewed-by: Jason Ekstrand <[email protected]>

2 files changed, 29 insertions, 0 deletions

diff --git a/src/mesa/drivers/dri/i965/brw_blorp.c b/src/mesa/drivers/dri/i965/brw_blorp.c
index 566899f8ccf..d91d03609a2 100644
--- a/src/mesa/drivers/dri/i965/brw_blorp.c
+++ b/src/mesa/drivers/dri/i965/brw_blorp.c
@@ -182,6 +182,13 @@ blorp_surf_for_miptree(struct brw_context *brw,
 
       surf->aux_addr.buffer = aux_buf->bo;
       surf->aux_addr.offset = aux_buf->offset;
+
+      if (devinfo->gen >= 10) {
+         surf->clear_color_addr = (struct blorp_address) {
+            .buffer = aux_buf->clear_color_bo,
+            .offset = aux_buf->clear_color_offset,
+         };
+      }
    } else {
       surf->aux_addr = (struct blorp_address) {
          .buffer = NULL,
diff --git a/src/mesa/drivers/dri/i965/brw_clear.c b/src/mesa/drivers/dri/i965/brw_clear.c
index 8aa83722ee9..63c0b241898 100644
--- a/src/mesa/drivers/dri/i965/brw_clear.c
+++ b/src/mesa/drivers/dri/i965/brw_clear.c
@@ -108,6 +108,7 @@ brw_fast_clear_depth(struct gl_context *ctx)
    struct intel_mipmap_tree *mt = depth_irb->mt;
    struct gl_renderbuffer_attachment *depth_att = &fb->Attachment[BUFFER_DEPTH];
    const struct gen_device_info *devinfo = &brw->screen->devinfo;
+   bool same_clear_value = true;
 
    if (devinfo->gen < 6)
       return false;
@@ -213,6 +214,7 @@ brw_fast_clear_depth(struct gl_context *ctx)
       }
 
       intel_miptree_set_depth_clear_value(ctx, mt, clear_value);
+      same_clear_value = false;
    }
 
    bool need_clear = false;
@@ -232,6 +234,26 @@ brw_fast_clear_depth(struct gl_context *ctx)
        * state then simply updating the miptree fast clear value is sufficient
        * to change their clear value.
        */
+      if (devinfo->gen >= 10 && !same_clear_value) {
+         /* Before gen10, it was enough to just update the clear value in the
+          * miptree. But on gen10+, we let blorp update the clear value state
+          * buffer when doing a fast clear. Since we are skipping the fast
+          * clear here, we need to update the clear color ourselves.
+          */
+         uint32_t clear_offset = mt->hiz_buf->clear_color_offset;
+         union isl_color_value clear_color = { .f32 = { clear_value, } };
+
+         /* We can't update the clear color while the hardware is still using
+          * the previous one for a resolve or sampling from it. So make sure
+          * that there's no pending commands at this point.
+          */
+         brw_emit_pipe_control_flush(brw, PIPE_CONTROL_CS_STALL);
+         for (int i = 0; i < 4; i++) {
+            brw_store_data_imm32(brw, mt->hiz_buf->clear_color_bo,
+                                 clear_offset + i * 4, clear_color.u32[i]);
+         }
+         brw_emit_pipe_control_flush(brw, PIPE_CONTROL_STATE_CACHE_INVALIDATE);
+      }
       return true;
    }