From c3a21fb0af3707fd5faa83136d0febbae1b2475e Mon Sep 17 00:00:00 2001
From: Ashley Smith <ashley.smith@collabora.com>
Date: Fri, 11 Jul 2025 09:47:29 +0100
Subject: [PATCH] bi/va: Add instructions required for KHR_shader_atomic_int64

Add 64-bit atomic instructions for bifrost/valhall

Reviewed-by: Mary Guillemard <mary.guillemard@collabora.com>
Reviewed-by: Eric R. Smith <eric.smith@collabora.com>
Signed-off-by: Ashley Smith <ashley.smith@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/35789>
---
 src/panfrost/compiler/bifrost/ISA.xml      | 65 ++++++++++++++++++++++
 src/panfrost/compiler/valhall/ISA.xml      |  3 +
 src/panfrost/compiler/valhall/valhall.c.py |  3 -
 3 files changed, 68 insertions(+), 3 deletions(-)

diff --git a/src/panfrost/compiler/bifrost/ISA.xml b/src/panfrost/compiler/bifrost/ISA.xml
index 4a080946822..4fc5d682187 100644
--- a/src/panfrost/compiler/bifrost/ISA.xml
+++ b/src/panfrost/compiler/bifrost/ISA.xml
@@ -8298,6 +8298,33 @@
     <immediate name="sr_count" size="4" pseudo="true"/>
   </ins>
 
+  <!-- Scheduler lowered to *ATOM_C.i64/+ATOM_CX. Real Valhall instructions. -->
+  <ins name="ATOM_RETURN.i64" pseudo="true" staging="rw=sr_count" message="atomic" unit="add">
+    <src start="0"/>
+    <src start="3"/>
+    <mod name="atom_opc" start="9" size="5">
+      <reserved/>
+      <reserved/>
+      <opt>aadd</opt>
+      <reserved/>
+      <reserved/>
+      <reserved/>
+      <reserved/>
+      <reserved/>
+      <opt>asmin</opt>
+      <opt>asmax</opt>
+      <opt>aumin</opt>
+      <opt>aumax</opt>
+      <opt>aand</opt>
+      <opt>aor</opt>
+      <opt>axor</opt>
+      <opt>axchg</opt> <!-- For Valhall -->
+      <opt>acmpxchg</opt> <!-- For Valhall -->
+    </mod>
+    <!-- not actually encoded, but used for IR -->
+    <immediate name="sr_count" size="4" pseudo="true"/>
+  </ins>
+
   <ins name="ATOM1_RETURN.i32" pseudo="true" staging="w=sr_count" message="atomic" unit="add">
     <src start="0"/>
     <src start="3"/>
@@ -8310,6 +8337,20 @@
     </mod>
     <!-- not actually encoded, but used for IR -->
     <immediate name="sr_count" size="4" pseudo="true"/>
+</ins>
+
+  <ins name="ATOM1_RETURN.i64" pseudo="true" staging="w=sr_count" message="atomic" unit="add">
+    <src start="0"/>
+    <src start="3"/>
+    <mod name="atom_opc" start="6" size="3">
+      <opt>ainc</opt>
+      <opt>adec</opt>
+      <opt>aumax1</opt>
+      <opt>asmax1</opt>
+      <opt>aor1</opt>
+    </mod>
+    <!-- not actually encoded, but used for IR -->
+    <immediate name="sr_count" size="4" pseudo="true"/>
   </ins>
 
   <ins name="ATOM.i32" pseudo="true" staging="r=sr_count" message="atomic" unit="add">
@@ -8336,6 +8377,30 @@
     <immediate name="sr_count" size="4" pseudo="true"/>
   </ins>
 
+  <ins name="ATOM.i64" pseudo="true" staging="r=sr_count" message="atomic" unit="add">
+    <src start="0"/>
+    <src start="3"/>
+    <mod name="atom_opc" start="9" size="4">
+      <reserved/>
+      <reserved/>
+      <opt>aadd</opt>
+      <reserved/>
+      <reserved/>
+      <reserved/>
+      <reserved/>
+      <reserved/>
+      <opt>asmin</opt>
+      <opt>asmax</opt>
+      <opt>aumin</opt>
+      <opt>aumax</opt>
+      <opt>aand</opt>
+      <opt>aor</opt>
+      <opt>axor</opt>
+    </mod>
+    <!-- not actually encoded, but used for IR -->
+    <immediate name="sr_count" size="4" pseudo="true"/>
+  </ins>
+
   <!-- *CUBEFACE1/+CUBEFACE2 pair, two destinations, scheduler lowered -->
   <ins name="CUBEFACE" pseudo="true" dests="2" unit="add">
     <src start="0"/>
diff --git a/src/panfrost/compiler/valhall/ISA.xml b/src/panfrost/compiler/valhall/ISA.xml
index 9708ea4caf9..6dd74f5e040 100644
--- a/src/panfrost/compiler/valhall/ISA.xml
+++ b/src/panfrost/compiler/valhall/ISA.xml
@@ -2508,7 +2508,10 @@
     <slot/>
     <sr_count/>
     <sr_write_count/>
+
+    <!-- Only valid with .xchg to implement ACMPXCHG -->
     <va_mod name="compare" start="26" size="1"/>
+
     <atom_opc/>
     <va_mod name="memory_width" start="128" size="1" implied="true"/>
 
diff --git a/src/panfrost/compiler/valhall/valhall.c.py b/src/panfrost/compiler/valhall/valhall.c.py
index da4f2fcd913..f17704b7ae7 100644
--- a/src/panfrost/compiler/valhall/valhall.c.py
+++ b/src/panfrost/compiler/valhall/valhall.c.py
@@ -57,9 +57,6 @@ SKIP = set([
         "RSHIFT_OR.i64",
         "LSHIFT_XOR.i64",
         "RSHIFT_XOR.i64",
-        "ATOM.i64",
-        "ATOM_RETURN.i64",
-        "ATOM1_RETURN.i64",
 
         # CLPER widens
         "CLPER.s32",