diff options
| -rw-r--r-- | arch/arm64/include/asm/barrier.h | 13 | ||||
| -rw-r--r-- | arch/arm64/include/asm/cmpxchg.h | 51 |
2 files changed, 64 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/barrier.h b/arch/arm64/include/asm/barrier.h index dae5c49618db..4eea7f618dce 100644 --- a/arch/arm64/include/asm/barrier.h +++ b/arch/arm64/include/asm/barrier.h @@ -91,6 +91,19 @@ do { \ __u.__val; \ }) +#define smp_cond_load_acquire(ptr, cond_expr) \ +({ \ + typeof(ptr) __PTR = (ptr); \ + typeof(*ptr) VAL; \ + for (;;) { \ + VAL = smp_load_acquire(__PTR); \ + if (cond_expr) \ + break; \ + __cmpwait_relaxed(__PTR, VAL); \ + } \ + VAL; \ +}) + #include <asm-generic/barrier.h> #endif /* __ASSEMBLY__ */ diff --git a/arch/arm64/include/asm/cmpxchg.h b/arch/arm64/include/asm/cmpxchg.h index 510c7b404454..bd86a79491bc 100644 --- a/arch/arm64/include/asm/cmpxchg.h +++ b/arch/arm64/include/asm/cmpxchg.h @@ -224,4 +224,55 @@ __CMPXCHG_GEN(_mb) __ret; \ }) +#define __CMPWAIT_CASE(w, sz, name) \ +static inline void __cmpwait_case_##name(volatile void *ptr, \ + unsigned long val) \ +{ \ + unsigned long tmp; \ + \ + asm volatile( \ + " ldxr" #sz "\t%" #w "[tmp], %[v]\n" \ + " eor %" #w "[tmp], %" #w "[tmp], %" #w "[val]\n" \ + " cbnz %" #w "[tmp], 1f\n" \ + " wfe\n" \ + "1:" \ + : [tmp] "=&r" (tmp), [v] "+Q" (*(unsigned long *)ptr) \ + : [val] "r" (val)); \ +} + +__CMPWAIT_CASE(w, b, 1); +__CMPWAIT_CASE(w, h, 2); +__CMPWAIT_CASE(w, , 4); +__CMPWAIT_CASE( , , 8); + +#undef __CMPWAIT_CASE + +#define __CMPWAIT_GEN(sfx) \ +static inline void __cmpwait##sfx(volatile void *ptr, \ + unsigned long val, \ + int size) \ +{ \ + switch (size) { \ + case 1: \ + return __cmpwait_case##sfx##_1(ptr, (u8)val); \ + case 2: \ + return __cmpwait_case##sfx##_2(ptr, (u16)val); \ + case 4: \ + return __cmpwait_case##sfx##_4(ptr, val); \ + case 8: \ + return __cmpwait_case##sfx##_8(ptr, val); \ + default: \ + BUILD_BUG(); \ + } \ + \ + unreachable(); \ +} + +__CMPWAIT_GEN() + +#undef __CMPWAIT_GEN + +#define __cmpwait_relaxed(ptr, val) \ + __cmpwait((ptr), (unsigned long)(val), sizeof(*(ptr))) + #endif /* __ASM_CMPXCHG_H */ |