From 630399469ffcb937936644fbaa5daf61e700a329 Mon Sep 17 00:00:00 2001
From: Mark Rutland <mark.rutland@arm.com>
Date: Mon, 5 Jun 2023 08:01:19 +0100
Subject: locking/atomic: scripts: simplify raw_atomic_long*() definitions

Currently, atomic-long is split into two sections, one defining the
raw_atomic_long_*() ops for CONFIG_64BIT, and one defining the raw
atomic_long_*() ops for !CONFIG_64BIT.

With many lines elided, this looks like:

| #ifdef CONFIG_64BIT
| ...
| static __always_inline bool
| raw_atomic_long_try_cmpxchg(atomic_long_t *v, long *old, long new)
| {
|         return raw_atomic64_try_cmpxchg(v, (s64 *)old, new);
| }
| ...
| #else /* CONFIG_64BIT */
| ...
| static __always_inline bool
| raw_atomic_long_try_cmpxchg(atomic_long_t *v, long *old, long new)
| {
|         return raw_atomic_try_cmpxchg(v, (int *)old, new);
| }
| ...
| #endif

The two definitions are spread far apart in the file, and duplicate the
prototype, making it hard to have a legible set of kerneldoc comments.

Make this simpler by defining the C prototype once, and writing the two
definitions inline. For example, the above becomes:

| static __always_inline bool
| raw_atomic_long_try_cmpxchg(atomic_long_t *v, long *old, long new)
| {
| #ifdef CONFIG_64BIT
|         return raw_atomic64_try_cmpxchg(v, (s64 *)old, new);
| #else
|         return raw_atomic_try_cmpxchg(v, (int *)old, new);
| #endif
| }

As we now always have a single copy of the C prototype wrapping all the
potential definitions, we now have an obvious single location for kerneldoc
comments. As a bonus, both the script and the generated file are
somewhat shorter.

There should be no functional change as a result of this patch.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20230605070124.3741859-23-mark.rutland@arm.com
---
 scripts/atomic/gen-atomic-long.sh | 27 +++++++++------------------
 1 file changed, 9 insertions(+), 18 deletions(-)

(limited to 'scripts')

diff --git a/scripts/atomic/gen-atomic-long.sh b/scripts/atomic/gen-atomic-long.sh
index 13832171f721..af27a71b37ef 100755
--- a/scripts/atomic/gen-atomic-long.sh
+++ b/scripts/atomic/gen-atomic-long.sh
@@ -32,7 +32,7 @@ gen_args_cast()
 	done
 }
 
-#gen_proto_order_variant(meta, pfx, name, sfx, order, atomic, int, arg...)
+#gen_proto_order_variant(meta, pfx, name, sfx, order, arg...)
 gen_proto_order_variant()
 {
 	local meta="$1"; shift
@@ -40,21 +40,24 @@ gen_proto_order_variant()
 	local name="$1"; shift
 	local sfx="$1"; shift
 	local order="$1"; shift
-	local atomic="$1"; shift
-	local int="$1"; shift
 
 	local atomicname="${pfx}${name}${sfx}${order}"
 
 	local ret="$(gen_ret_type "${meta}" "long")"
 	local params="$(gen_params "long" "atomic_long" "$@")"
-	local argscast="$(gen_args_cast "${int}" "${atomic}" "$@")"
+	local argscast_32="$(gen_args_cast "int" "atomic" "$@")"
+	local argscast_64="$(gen_args_cast "s64" "atomic64" "$@")"
 	local retstmt="$(gen_ret_stmt "${meta}")"
 
 cat <<EOF
 static __always_inline ${ret}
 raw_atomic_long_${atomicname}(${params})
 {
-	${retstmt}raw_${atomic}_${atomicname}(${argscast});
+#ifdef CONFIG_64BIT
+	${retstmt}raw_atomic64_${atomicname}(${argscast_64});
+#else
+	${retstmt}raw_atomic_${atomicname}(${argscast_32});
+#endif
 }
 
 EOF
@@ -84,24 +87,12 @@ typedef atomic_t atomic_long_t;
 #define atomic_long_cond_read_relaxed	atomic_cond_read_relaxed
 #endif
 
-#ifdef CONFIG_64BIT
-
-EOF
-
-grep '^[a-z]' "$1" | while read name meta args; do
-	gen_proto "${meta}" "${name}" "atomic64" "s64" ${args}
-done
-
-cat <<EOF
-#else /* CONFIG_64BIT */
-
 EOF
 
 grep '^[a-z]' "$1" | while read name meta args; do
-	gen_proto "${meta}" "${name}" "atomic" "int" ${args}
+	gen_proto "${meta}" "${name}" ${args}
 done
 
 cat <<EOF
-#endif /* CONFIG_64BIT */
 #endif /* _LINUX_ATOMIC_LONG_H */
 EOF
-- 
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