Implement FETCH-OP atomic primitives, these are very similar to the existing OP-RETURN primitives we already have, except they return the value of the atomic variable _before_ modification. This is especially useful for irreversible operations -- such as bitops (because it becomes impossible to reconstruct the state prior to modification). [wildea01: compile fixes for ll/sc] Signed-off-by: Peter Zijlstra (Intel) --- arch/arm64/include/asm/atomic.h | 62 +++++++++++++++++++ arch/arm64/include/asm/atomic_ll_sc.h | 110 ++++++++++++++++++++++++++-------- 2 files changed, 148 insertions(+), 24 deletions(-) --- a/arch/arm64/include/asm/atomic.h +++ b/arch/arm64/include/asm/atomic.h @@ -76,6 +76,36 @@ #define atomic_dec_return_release(v) atomic_sub_return_release(1, (v)) #define atomic_dec_return(v) atomic_sub_return(1, (v)) +#define atomic_fetch_add_relaxed atomic_fetch_add_relaxed +#define atomic_fetch_add_acquire atomic_fetch_add_acquire +#define atomic_fetch_add_release atomic_fetch_add_release +#define atomic_fetch_add atomic_fetch_add + +#define atomic_fetch_sub_relaxed atomic_fetch_sub_relaxed +#define atomic_fetch_sub_acquire atomic_fetch_sub_acquire +#define atomic_fetch_sub_release atomic_fetch_sub_release +#define atomic_fetch_sub atomic_fetch_sub + +#define atomic_fetch_and_relaxed atomic_fetch_and_relaxed +#define atomic_fetch_and_acquire atomic_fetch_and_acquire +#define atomic_fetch_and_release atomic_fetch_and_release +#define atomic_fetch_and atomic_fetch_and + +#define atomic_fetch_andnot_relaxed atomic_fetch_andnot_relaxed +#define atomic_fetch_andnot_acquire atomic_fetch_andnot_acquire +#define atomic_fetch_andnot_release atomic_fetch_andnot_release +#define atomic_fetch_andnot atomic_fetch_andnot + +#define atomic_fetch_or_relaxed atomic_fetch_or_relaxed +#define atomic_fetch_or_acquire atomic_fetch_or_acquire +#define atomic_fetch_or_release atomic_fetch_or_release +#define atomic_fetch_or atomic_fetch_or + +#define atomic_fetch_xor_relaxed atomic_fetch_xor_relaxed +#define atomic_fetch_xor_acquire atomic_fetch_xor_acquire +#define atomic_fetch_xor_release atomic_fetch_xor_release +#define atomic_fetch_xor atomic_fetch_xor + #define atomic_xchg_relaxed(v, new) xchg_relaxed(&((v)->counter), (new)) #define atomic_xchg_acquire(v, new) xchg_acquire(&((v)->counter), (new)) #define atomic_xchg_release(v, new) xchg_release(&((v)->counter), (new)) @@ -98,6 +128,8 @@ #define __atomic_add_unless(v, a, u) ___atomic_add_unless(v, a, u,) #define atomic_andnot atomic_andnot +#define atomic_fetch_or atomic_fetch_or + /* * 64-bit atomic operations. */ @@ -125,6 +157,36 @@ #define atomic64_dec_return_release(v) atomic64_sub_return_release(1, (v)) #define atomic64_dec_return(v) atomic64_sub_return(1, (v)) +#define atomic64_fetch_add_relaxed atomic64_fetch_add_relaxed +#define atomic64_fetch_add_acquire atomic64_fetch_add_acquire +#define atomic64_fetch_add_release atomic64_fetch_add_release +#define atomic64_fetch_add atomic64_fetch_add + +#define atomic64_fetch_sub_relaxed atomic64_fetch_sub_relaxed +#define atomic64_fetch_sub_acquire atomic64_fetch_sub_acquire +#define atomic64_fetch_sub_release atomic64_fetch_sub_release +#define atomic64_fetch_sub atomic64_fetch_sub + +#define atomic64_fetch_and_relaxed atomic64_fetch_and_relaxed +#define atomic64_fetch_and_acquire atomic64_fetch_and_acquire +#define atomic64_fetch_and_release atomic64_fetch_and_release +#define atomic64_fetch_and atomic64_fetch_and + +#define atomic64_fetch_andnot_relaxed atomic64_fetch_andnot_relaxed +#define atomic64_fetch_andnot_acquire atomic64_fetch_andnot_acquire +#define atomic64_fetch_andnot_release atomic64_fetch_andnot_release +#define atomic64_fetch_andnot atomic64_fetch_andnot + +#define atomic64_fetch_or_relaxed atomic64_fetch_or_relaxed +#define atomic64_fetch_or_acquire atomic64_fetch_or_acquire +#define atomic64_fetch_or_release atomic64_fetch_or_release +#define atomic64_fetch_or atomic64_fetch_or + +#define atomic64_fetch_xor_relaxed atomic64_fetch_xor_relaxed +#define atomic64_fetch_xor_acquire atomic64_fetch_xor_acquire +#define atomic64_fetch_xor_release atomic64_fetch_xor_release +#define atomic64_fetch_xor atomic64_fetch_xor + #define atomic64_xchg_relaxed atomic_xchg_relaxed #define atomic64_xchg_acquire atomic_xchg_acquire #define atomic64_xchg_release atomic_xchg_release --- a/arch/arm64/include/asm/atomic_ll_sc.h +++ b/arch/arm64/include/asm/atomic_ll_sc.h @@ -77,26 +77,57 @@ __LL_SC_PREFIX(atomic_##op##_return##nam } \ __LL_SC_EXPORT(atomic_##op##_return##name); +#define ATOMIC_FETCH_OP(name, mb, acq, rel, cl, op, asm_op) \ +__LL_SC_INLINE int \ +__LL_SC_PREFIX(atomic_fetch_##op##name(int i, atomic_t *v)) \ +{ \ + unsigned long tmp; \ + int val, result; \ + \ + asm volatile("// atomic_fetch_" #op #name "\n" \ +" prfm pstl1strm, %3\n" \ +"1: ld" #acq "xr %w0, %3\n" \ +" " #asm_op " %w1, %w0, %w4\n" \ +" st" #rel "xr %w2, %w1, %3\n" \ +" cbnz %w2, 1b\n" \ +" " #mb \ + : "=&r" (result), "=&r" (val), "=&r" (tmp), "+Q" (v->counter) \ + : "Ir" (i) \ + : cl); \ + \ + return result; \ +} \ +__LL_SC_EXPORT(atomic_fetch_##op##name); + #define ATOMIC_OPS(...) \ ATOMIC_OP(__VA_ARGS__) \ - ATOMIC_OP_RETURN( , dmb ish, , l, "memory", __VA_ARGS__) - -#define ATOMIC_OPS_RLX(...) \ - ATOMIC_OPS(__VA_ARGS__) \ + ATOMIC_OP_RETURN( , dmb ish, , l, "memory", __VA_ARGS__)\ ATOMIC_OP_RETURN(_relaxed, , , , , __VA_ARGS__)\ ATOMIC_OP_RETURN(_acquire, , a, , "memory", __VA_ARGS__)\ - ATOMIC_OP_RETURN(_release, , , l, "memory", __VA_ARGS__) + ATOMIC_OP_RETURN(_release, , , l, "memory", __VA_ARGS__)\ + ATOMIC_FETCH_OP ( , dmb ish, , l, "memory", __VA_ARGS__)\ + ATOMIC_FETCH_OP (_relaxed, , , , , __VA_ARGS__)\ + ATOMIC_FETCH_OP (_acquire, , a, , "memory", __VA_ARGS__)\ + ATOMIC_FETCH_OP (_release, , , l, "memory", __VA_ARGS__) -ATOMIC_OPS_RLX(add, add) -ATOMIC_OPS_RLX(sub, sub) +ATOMIC_OPS(add, add) +ATOMIC_OPS(sub, sub) -ATOMIC_OP(and, and) -ATOMIC_OP(andnot, bic) -ATOMIC_OP(or, orr) -ATOMIC_OP(xor, eor) +#undef ATOMIC_OPS +#define ATOMIC_OPS(...) \ + ATOMIC_OP(__VA_ARGS__) \ + ATOMIC_FETCH_OP ( , dmb ish, , l, "memory", __VA_ARGS__)\ + ATOMIC_FETCH_OP (_relaxed, , , , , __VA_ARGS__)\ + ATOMIC_FETCH_OP (_acquire, , a, , "memory", __VA_ARGS__)\ + ATOMIC_FETCH_OP (_release, , , l, "memory", __VA_ARGS__) + +ATOMIC_OPS(and, and) +ATOMIC_OPS(andnot, bic) +ATOMIC_OPS(or, orr) +ATOMIC_OPS(xor, eor) -#undef ATOMIC_OPS_RLX #undef ATOMIC_OPS +#undef ATOMIC_FETCH_OP #undef ATOMIC_OP_RETURN #undef ATOMIC_OP @@ -140,26 +171,57 @@ __LL_SC_PREFIX(atomic64_##op##_return##n } \ __LL_SC_EXPORT(atomic64_##op##_return##name); +#define ATOMIC64_FETCH_OP(name, mb, acq, rel, cl, op, asm_op) \ +__LL_SC_INLINE long \ +__LL_SC_PREFIX(atomic64_fetch_##op##name(long i, atomic64_t *v)) \ +{ \ + long result, val; \ + unsigned long tmp; \ + \ + asm volatile("// atomic64_fetch_" #op #name "\n" \ +" prfm pstl1strm, %3\n" \ +"1: ld" #acq "xr %0, %3\n" \ +" " #asm_op " %1, %0, %4\n" \ +" st" #rel "xr %w2, %1, %3\n" \ +" cbnz %w2, 1b\n" \ +" " #mb \ + : "=&r" (result), "=&r" (val), "=&r" (tmp), "+Q" (v->counter) \ + : "Ir" (i) \ + : cl); \ + \ + return result; \ +} \ +__LL_SC_EXPORT(atomic64_fetch_##op##name); + #define ATOMIC64_OPS(...) \ ATOMIC64_OP(__VA_ARGS__) \ - ATOMIC64_OP_RETURN(, dmb ish, , l, "memory", __VA_ARGS__) - -#define ATOMIC64_OPS_RLX(...) \ - ATOMIC64_OPS(__VA_ARGS__) \ + ATOMIC64_OP_RETURN(, dmb ish, , l, "memory", __VA_ARGS__) \ ATOMIC64_OP_RETURN(_relaxed,, , , , __VA_ARGS__) \ ATOMIC64_OP_RETURN(_acquire,, a, , "memory", __VA_ARGS__) \ - ATOMIC64_OP_RETURN(_release,, , l, "memory", __VA_ARGS__) + ATOMIC64_OP_RETURN(_release,, , l, "memory", __VA_ARGS__) \ + ATOMIC64_FETCH_OP (, dmb ish, , l, "memory", __VA_ARGS__) \ + ATOMIC64_FETCH_OP (_relaxed,, , , , __VA_ARGS__) \ + ATOMIC64_FETCH_OP (_acquire,, a, , "memory", __VA_ARGS__) \ + ATOMIC64_FETCH_OP (_release,, , l, "memory", __VA_ARGS__) -ATOMIC64_OPS_RLX(add, add) -ATOMIC64_OPS_RLX(sub, sub) +ATOMIC64_OPS(add, add) +ATOMIC64_OPS(sub, sub) -ATOMIC64_OP(and, and) -ATOMIC64_OP(andnot, bic) -ATOMIC64_OP(or, orr) -ATOMIC64_OP(xor, eor) +#undef ATOMIC64_OPS +#define ATOMIC64_OPS(...) \ + ATOMIC64_OP(__VA_ARGS__) \ + ATOMIC64_FETCH_OP (, dmb ish, , l, "memory", __VA_ARGS__) \ + ATOMIC64_FETCH_OP (_relaxed,, , , , __VA_ARGS__) \ + ATOMIC64_FETCH_OP (_acquire,, a, , "memory", __VA_ARGS__) \ + ATOMIC64_FETCH_OP (_release,, , l, "memory", __VA_ARGS__) + +ATOMIC64_OPS(and, and) +ATOMIC64_OPS(andnot, bic) +ATOMIC64_OPS(or, orr) +ATOMIC64_OPS(xor, eor) -#undef ATOMIC64_OPS_RLX #undef ATOMIC64_OPS +#undef ATOMIC64_FETCH_OP #undef ATOMIC64_OP_RETURN #undef ATOMIC64_OP