Mesa (staging/21.2): intel/fs: fix framebuffer reads

[GitLab Mirror]

Module: Mesa
Branch: staging/21.2
Commit: 25f91e6ab9c0f1efbcae820f2973b447d01550fb
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=25f91e6ab9c0f1efbcae820f2973b447d01550fb

Author: Lionel Landwerlin <lionel.g.landwerlin at intel.com>
Date:   Mon Aug 30 13:03:26 2021 +0300

intel/fs: fix framebuffer reads

We're missing some restrictions on those messages.

Signed-off-by: Lionel Landwerlin <lionel.g.landwerlin at intel.com>
Closes: https://gitlab.freedesktop.org/mesa/mesa/-/issues/5292
Cc: mesa-stable
Reviewed-by: Jordan Justen <jordan.l.justen at intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/12615>
(cherry picked from commit 838c0e5eefd444df701b6d9cbcef1b06eb5eb207)

---

 .pick_status.json             |  2 +-
 src/intel/compiler/brw_fs.cpp | 14 ++++++++++++++
 2 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/.pick_status.json b/.pick_status.json
index 3514a1cc1f9..18235d38cff 100644
--- a/.pick_status.json
+++ b/.pick_status.json
@@ -31,7 +31,7 @@
         "description": "intel/fs: fix framebuffer reads",
         "nominated": true,
         "nomination_type": 0,
-        "resolution": 0,
+        "resolution": 1,
         "main_sha": null,
         "because_sha": null
     },
diff --git a/src/intel/compiler/brw_fs.cpp b/src/intel/compiler/brw_fs.cpp
index 2735a430ec3..8fbb35cf7c0 100644
--- a/src/intel/compiler/brw_fs.cpp
+++ b/src/intel/compiler/brw_fs.cpp
@@ -4871,6 +4871,20 @@ lower_fb_read_logical_send(const fs_builder &bld, fs_inst *inst)
       }
    }
 
+   /* BSpec 12470 (Gfx8-11), BSpec 47842 (Gfx12+) :
+    *
+    *   "Must be zero for Render Target Read message."
+    *
+    * For bits :
+    *   - 14 : Stencil Present to Render Target
+    *   - 13 : Source Depth Present to Render Target
+    *   - 12 : oMask to Render Target
+    *   - 11 : Source0 Alpha Present to Render Target
+    */
+   ubld.group(1, 0).AND(component(header, 0),
+                        component(header, 0),
+                        brw_imm_ud(~INTEL_MASK(14, 11)));
+
    inst->resize_sources(1);
    inst->src[0] = header;
    inst->opcode = FS_OPCODE_FB_READ;