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@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20230605070124.3741859-7-mark.rutland@arm.com

diff --git a/arch/arm/include/asm/atomic.h b/arch/arm/include/asm/atomic.h
index 9458d47..f0e3b01 100644 (file)
--- 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)                                   \