[tip: locking/core] locking/atomic: arm: add preprocessor symbols

[tip-bot2 for Mark Rutland]

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

Commit-ID:     d6cd3664806fbe8313b8e04b042d40e8135ca459
Gitweb:        https://git.kernel.org/tip/d6cd3664806fbe8313b8e04b042d40e8135ca459
Author:        Mark Rutland <mark.rutland@xxxxxxx>
AuthorDate:    Mon, 05 Jun 2023 08:01:03 +01:00
Committer:     Peter Zijlstra <peterz@xxxxxxxxxxxxx>
CommitterDate: Mon, 05 Jun 2023 09:57:15 +02:00

locking/atomic: arm: add preprocessor symbols

Some atomics can be implemented in several different ways, e.g.
FULL/ACQUIRE/RELEASE ordered atomics can be implemented in terms of
RELAXED atomics, and ACQUIRE/RELEASE/RELAXED can be implemented in terms
of FULL ordered atomics. Other atomics are optional, and don't exist in
some configurations (e.g. not all architectures implement the 128-bit
cmpxchg ops).

Subsequent patches will require that architectures define a preprocessor
symbol for any atomic (or ordering variant) which is optional. This will
make the fallback ifdeffery more robust, and simplify future changes.

Add the required definitions to arch/arm.

Signed-off-by: Mark Rutland <mark.rutland@xxxxxxx>
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20230605070124.3741859-7-mark.rutland@xxxxxxx
---
 arch/arm/include/asm/atomic.h | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/arch/arm/include/asm/atomic.h b/arch/arm/include/asm/atomic.h
index 9458d47..f0e3b01 100644
--- a/arch/arm/include/asm/atomic.h
+++ b/arch/arm/include/asm/atomic.h
@@ -197,6 +197,16 @@ static inline int arch_atomic_fetch_##op(int i, atomic_t *v)		\
 	return val;							\
 }
 
+#define arch_atomic_add_return			arch_atomic_add_return
+#define arch_atomic_sub_return			arch_atomic_sub_return
+#define arch_atomic_fetch_add			arch_atomic_fetch_add
+#define arch_atomic_fetch_sub			arch_atomic_fetch_sub
+
+#define arch_atomic_fetch_and			arch_atomic_fetch_and
+#define arch_atomic_fetch_andnot		arch_atomic_fetch_andnot
+#define arch_atomic_fetch_or			arch_atomic_fetch_or
+#define arch_atomic_fetch_xor			arch_atomic_fetch_xor
+
 static inline int arch_atomic_cmpxchg(atomic_t *v, int old, int new)
 {
 	int ret;
@@ -212,8 +222,6 @@ static inline int arch_atomic_cmpxchg(atomic_t *v, int old, int new)
 }
 #define arch_atomic_cmpxchg arch_atomic_cmpxchg
 
-#define arch_atomic_fetch_andnot		arch_atomic_fetch_andnot
-
 #endif /* __LINUX_ARM_ARCH__ */
 
 #define ATOMIC_OPS(op, c_op, asm_op)					\