[tip: locking/core] locking/generic: Wire up local{,64}_try_cmpxchg()

[tip-bot2 for Uros Bizjak]

The following commit has been merged into the locking/core branch of tip:

Commit-ID:     8fc4fddaf9a184eea7da21290236a1764e608a01
Gitweb:        https://git.kernel.org/tip/8fc4fddaf9a184eea7da21290236a1764e608a01
Author:        Uros Bizjak <ubizjak@xxxxxxxxx>
AuthorDate:    Wed, 05 Apr 2023 16:17:07 +02:00
Committer:     Ingo Molnar <mingo@xxxxxxxxxx>
CommitterDate: Sat, 29 Apr 2023 09:09:09 +02:00

locking/generic: Wire up local{,64}_try_cmpxchg()

Implement generic support for local{,64}_try_cmpxchg().

Redirect to the atomic_ family of functions when the target
does not provide its own local.h definitions.

For 64-bit targets, implement local64_try_cmpxchg and
local64_cmpxchg using typed C wrappers that call local_
family of functions and provide additional checking
of their input arguments.

Signed-off-by: Uros Bizjak <ubizjak@xxxxxxxxx>
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
Acked-by: Mark Rutland <mark.rutland@xxxxxxx>
Link: https://lore.kernel.org/r/20230405141710.3551-3-ubizjak@xxxxxxxxx
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
---
 include/asm-generic/local.h   |  1 +
 include/asm-generic/local64.h | 12 +++++++++++-
 2 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/include/asm-generic/local.h b/include/asm-generic/local.h
index fca7f1d..7f97018 100644
--- a/include/asm-generic/local.h
+++ b/include/asm-generic/local.h
@@ -42,6 +42,7 @@ typedef struct
 #define local_inc_return(l) atomic_long_inc_return(&(l)->a)
 
 #define local_cmpxchg(l, o, n) atomic_long_cmpxchg((&(l)->a), (o), (n))
+#define local_try_cmpxchg(l, po, n) atomic_long_try_cmpxchg((&(l)->a), (po), (n))
 #define local_xchg(l, n) atomic_long_xchg((&(l)->a), (n))
 #define local_add_unless(l, _a, u) atomic_long_add_unless((&(l)->a), (_a), (u))
 #define local_inc_not_zero(l) atomic_long_inc_not_zero(&(l)->a)
diff --git a/include/asm-generic/local64.h b/include/asm-generic/local64.h
index 765be0b..14963a7 100644
--- a/include/asm-generic/local64.h
+++ b/include/asm-generic/local64.h
@@ -42,7 +42,16 @@ typedef struct {
 #define local64_sub_return(i, l) local_sub_return((i), (&(l)->a))
 #define local64_inc_return(l)	local_inc_return(&(l)->a)
 
-#define local64_cmpxchg(l, o, n) local_cmpxchg((&(l)->a), (o), (n))
+static inline s64 local64_cmpxchg(local64_t *l, s64 old, s64 new)
+{
+	return local_cmpxchg(&l->a, old, new);
+}
+
+static inline bool local64_try_cmpxchg(local64_t *l, s64 *old, s64 new)
+{
+	return local_try_cmpxchg(&l->a, (long *)old, new);
+}
+
 #define local64_xchg(l, n)	local_xchg((&(l)->a), (n))
 #define local64_add_unless(l, _a, u) local_add_unless((&(l)->a), (_a), (u))
 #define local64_inc_not_zero(l)	local_inc_not_zero(&(l)->a)
@@ -81,6 +90,7 @@ typedef struct {
 #define local64_inc_return(l)	atomic64_inc_return(&(l)->a)
 
 #define local64_cmpxchg(l, o, n) atomic64_cmpxchg((&(l)->a), (o), (n))
+#define local64_try_cmpxchg(l, po, n) atomic64_try_cmpxchg((&(l)->a), (po), (n))
 #define local64_xchg(l, n)	atomic64_xchg((&(l)->a), (n))
 #define local64_add_unless(l, _a, u) atomic64_add_unless((&(l)->a), (_a), (u))
 #define local64_inc_not_zero(l)	atomic64_inc_not_zero(&(l)->a)