From d12157efc8e083c77d054675fcdd594f54cc7e2b Mon Sep 17 00:00:00 2001 From: Mark Rutland Date: Mon, 5 Jun 2023 08:01:01 +0100 Subject: locking/atomic: make atomic*_{cmp,}xchg optional Most architectures define the atomic/atomic64 xchg and cmpxchg operations in terms of arch_xchg and arch_cmpxchg respectfully. Add fallbacks for these cases and remove the trivial cases from arch code. On some architectures the existing definitions are kept as these are used to build other arch_atomic*() operations. Signed-off-by: Mark Rutland Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Kees Cook Link: https://lore.kernel.org/r/20230605070124.3741859-5-mark.rutland@arm.com --- arch/m68k/include/asm/atomic.h | 9 +++------ 1 file changed, 3 insertions(+), 6 deletions(-) (limited to 'arch/m68k') diff --git a/arch/m68k/include/asm/atomic.h b/arch/m68k/include/asm/atomic.h index cfba83d230fd..190a032f19be 100644 --- a/arch/m68k/include/asm/atomic.h +++ b/arch/m68k/include/asm/atomic.h @@ -158,12 +158,7 @@ static inline int arch_atomic_inc_and_test(atomic_t *v) } #define arch_atomic_inc_and_test arch_atomic_inc_and_test -#ifdef CONFIG_RMW_INSNS - -#define arch_atomic_cmpxchg(v, o, n) ((int)arch_cmpxchg(&((v)->counter), (o), (n))) -#define arch_atomic_xchg(v, new) (arch_xchg(&((v)->counter), new)) - -#else /* !CONFIG_RMW_INSNS */ +#ifndef CONFIG_RMW_INSNS static inline int arch_atomic_cmpxchg(atomic_t *v, int old, int new) { @@ -177,6 +172,7 @@ static inline int arch_atomic_cmpxchg(atomic_t *v, int old, int new) local_irq_restore(flags); return prev; } +#define arch_atomic_cmpxchg arch_atomic_cmpxchg static inline int arch_atomic_xchg(atomic_t *v, int new) { @@ -189,6 +185,7 @@ static inline int arch_atomic_xchg(atomic_t *v, int new) local_irq_restore(flags); return prev; } +#define arch_atomic_xchg arch_atomic_xchg #endif /* !CONFIG_RMW_INSNS */ -- cgit From e50f06ce2d876c740993b5e3d01e203520391ccd Mon Sep 17 00:00:00 2001 From: Mark Rutland Date: Mon, 5 Jun 2023 08:01:05 +0100 Subject: locking/atomic: m68k: 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/m68k. Signed-off-by: Mark Rutland Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Kees Cook Link: https://lore.kernel.org/r/20230605070124.3741859-9-mark.rutland@arm.com --- arch/m68k/include/asm/atomic.h | 9 +++++++++ 1 file changed, 9 insertions(+) (limited to 'arch/m68k') diff --git a/arch/m68k/include/asm/atomic.h b/arch/m68k/include/asm/atomic.h index 190a032f19be..4bfbc25f6ecf 100644 --- a/arch/m68k/include/asm/atomic.h +++ b/arch/m68k/include/asm/atomic.h @@ -106,6 +106,11 @@ static inline int arch_atomic_fetch_##op(int i, atomic_t * v) \ ATOMIC_OPS(add, +=, add) ATOMIC_OPS(sub, -=, sub) +#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 + #undef ATOMIC_OPS #define ATOMIC_OPS(op, c_op, asm_op) \ ATOMIC_OP(op, c_op, asm_op) \ @@ -115,6 +120,10 @@ ATOMIC_OPS(and, &=, and) ATOMIC_OPS(or, |=, or) ATOMIC_OPS(xor, ^=, eor) +#define arch_atomic_fetch_and arch_atomic_fetch_and +#define arch_atomic_fetch_or arch_atomic_fetch_or +#define arch_atomic_fetch_xor arch_atomic_fetch_xor + #undef ATOMIC_OPS #undef ATOMIC_FETCH_OP #undef ATOMIC_OP_RETURN -- cgit