Mesa (master): i965/skl: Utilize new 5th bit for gateway messages

[Ben Widawsky]

Module: Mesa
Branch: master
Commit: 0e06f76a848a5f556a40933791ffe2a9c0d4e979
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=0e06f76a848a5f556a40933791ffe2a9c0d4e979

Author: Ben Widawsky <benjamin.widawsky at intel.com>
Date:   Tue Jan 26 15:44:01 2016 -0800

i965/skl: Utilize new 5th bit for gateway messages

Modify comment as spotted by Matt, and Chris Forbes

Signed-off-by: Ben Widawsky <benjamin.widawsky at intel.com>
Reviewed-by: Matt Turner <mattst88 at gmail.com>
Reviewed-by: Jordan Justen <jordan.l.justen at intel.com>

---

 src/mesa/drivers/dri/i965/brw_fs_visitor.cpp | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/src/mesa/drivers/dri/i965/brw_fs_visitor.cpp b/src/mesa/drivers/dri/i965/brw_fs_visitor.cpp
index aad512f..a74ed72 100644
--- a/src/mesa/drivers/dri/i965/brw_fs_visitor.cpp
+++ b/src/mesa/drivers/dri/i965/brw_fs_visitor.cpp
@@ -924,6 +924,8 @@ void
 fs_visitor::emit_barrier()
 {
    assert(devinfo->gen >= 7);
+   const uint32_t barrier_id_mask =
+      devinfo->gen >= 9 ? 0x8f000000u : 0x0f000000u;
 
    /* We are getting the barrier ID from the compute shader header */
    assert(stage == MESA_SHADER_COMPUTE);
@@ -935,9 +937,9 @@ fs_visitor::emit_barrier()
    /* Clear the message payload */
    pbld.MOV(payload, brw_imm_ud(0u));
 
-   /* Copy bits 27:24 of r0.2 (barrier id) to the message payload reg.2 */
+   /* Copy the barrier id from r0.2 to the message payload reg.2 */
    fs_reg r0_2 = fs_reg(retype(brw_vec1_grf(0, 2), BRW_REGISTER_TYPE_UD));
-   pbld.AND(component(payload, 2), r0_2, brw_imm_ud(0x0f000000u));
+   pbld.AND(component(payload, 2), r0_2, brw_imm_ud(barrier_id_mask));
 
    /* Emit a gateway "barrier" message using the payload we set up, followed
     * by a wait instruction.