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@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20230405141710.3551-3-ubizjak@gmail.com
Cc: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/include/asm-generic/local.h b/include/asm-generic/local.h
index fca7f1d8481822848d263aaa863291bd9eb7f2d3..7f97018df66fec26b70c1fb292941c59efe260d6 100644 (file)
--- 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 765be0b7d88306eaec9216b1dd1dd89a4199b6f1..14963a7a62538b2c0e44404c8a7afafccaa5a85c 100644 (file)
--- 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)