From e24984efd5c6ac5ea8e6cb6cd914fa8435d458bc Mon Sep 17 00:00:00 2001 From: Rich Felker Date: Fri, 22 Jan 2016 00:16:53 +0000 Subject: [PATCH] clean up i386 atomics for new atomics framework this commit mostly makes consistent things like spacing, function ordering in atomic_arch.h, argument names, use of volatile, etc. the fake 64-bit and/or atomics are also removed because the shared atomic.h does a better job of implementing them; it avoids making two atomic memory accesses when only one 32-bit half needs to be touched. no major overhaul is needed or possible because x86 actually has native versions of all the usual atomic operations, rather than using ll/sc or needing cas loops. --- arch/i386/atomic_arch.h | 124 +++++++++++++++++++--------------------- 1 file changed, 58 insertions(+), 66 deletions(-) diff --git a/arch/i386/atomic_arch.h b/arch/i386/atomic_arch.h index 5de862ed..6e67c4ce 100644 --- a/arch/i386/atomic_arch.h +++ b/arch/i386/atomic_arch.h @@ -1,99 +1,68 @@ -#define a_ctz_64 a_ctz_64 -static inline int a_ctz_64(uint64_t x) -{ - int r; - __asm__( "bsf %1,%0 ; jnz 1f ; bsf %2,%0 ; addl $32,%0\n1:" - : "=&r"(r) : "r"((unsigned)x), "r"((unsigned)(x>>32)) ); - return r; -} - -#define a_ctz_l a_ctz_l -static inline int a_ctz_l(unsigned long x) -{ - long r; - __asm__( "bsf %1,%0" : "=r"(r) : "r"(x) ); - return r; -} - -#define a_and_64 a_and_64 -static inline void a_and_64(volatile uint64_t *p, uint64_t v) -{ - __asm__( "lock ; andl %1, (%0) ; lock ; andl %2, 4(%0)" - : : "r"((long *)p), "r"((unsigned)v), "r"((unsigned)(v>>32)) : "memory" ); -} - -#define a_or_64 a_or_64 -static inline void a_or_64(volatile uint64_t *p, uint64_t v) -{ - __asm__( "lock ; orl %1, (%0) ; lock ; orl %2, 4(%0)" - : : "r"((long *)p), "r"((unsigned)v), "r"((unsigned)(v>>32)) : "memory" ); -} - -#define a_or_l a_or_l -static inline void a_or_l(volatile void *p, long v) -{ - __asm__( "lock ; orl %1, %0" - : "=m"(*(long *)p) : "r"(v) : "memory" ); -} - #define a_cas a_cas static inline int a_cas(volatile int *p, int t, int s) { - __asm__( "lock ; cmpxchg %3, %1" + __asm__ __volatile__ ( + "lock ; cmpxchg %3, %1" : "=a"(t), "=m"(*p) : "a"(t), "r"(s) : "memory" ); return t; } -#define a_or a_or -static inline void a_or(volatile int *p, int v) +#define a_swap a_swap +static inline int a_swap(volatile int *p, int v) { - __asm__( "lock ; orl %1, %0" - : "=m"(*p) : "r"(v) : "memory" ); + __asm__ __volatile__( + "xchg %0, %1" + : "=r"(v), "=m"(*p) : "0"(v) : "memory" ); + return v; } -#define a_and a_and -static inline void a_and(volatile int *p, int v) +#define a_fetch_add a_fetch_add +static inline int a_fetch_add(volatile int *p, int v) { - __asm__( "lock ; andl %1, %0" - : "=m"(*p) : "r"(v) : "memory" ); + __asm__ __volatile__( + "lock ; xadd %0, %1" + : "=r"(v), "=m"(*p) : "0"(v) : "memory" ); + return v; } -#define a_swap a_swap -static inline int a_swap(volatile int *x, int v) +#define a_and a_and +static inline void a_and(volatile int *p, int v) { - __asm__( "xchg %0, %1" : "=r"(v), "=m"(*x) : "0"(v) : "memory" ); - return v; + __asm__ __volatile__( + "lock ; and %1, %0" + : "=m"(*p) : "r"(v) : "memory" ); } -#define a_fetch_add a_fetch_add -static inline int a_fetch_add(volatile int *x, int v) +#define a_or a_or +static inline void a_or(volatile int *p, int v) { - __asm__( "lock ; xadd %0, %1" : "=r"(v), "=m"(*x) : "0"(v) : "memory" ); - return v; + __asm__ __volatile__( + "lock ; or %1, %0" + : "=m"(*p) : "r"(v) : "memory" ); } #define a_inc a_inc -static inline void a_inc(volatile int *x) +static inline void a_inc(volatile int *p) { - __asm__( "lock ; incl %0" : "=m"(*x) : "m"(*x) : "memory" ); + __asm__ __volatile__( + "lock ; incl %0" + : "=m"(*p) : "m"(*p) : "memory" ); } #define a_dec a_dec -static inline void a_dec(volatile int *x) +static inline void a_dec(volatile int *p) { - __asm__( "lock ; decl %0" : "=m"(*x) : "m"(*x) : "memory" ); + __asm__ __volatile__( + "lock ; decl %0" + : "=m"(*p) : "m"(*p) : "memory" ); } #define a_store a_store static inline void a_store(volatile int *p, int x) { - __asm__( "movl %1, %0 ; lock ; orl $0,(%%esp)" : "=m"(*p) : "r"(x) : "memory" ); -} - -#define a_spin a_spin -static inline void a_spin() -{ - __asm__ __volatile__( "pause" : : : "memory" ); + __asm__ __volatile__( + "mov %1, %0 ; lock ; orl $0,(%%esp)" + : "=m"(*p) : "r"(x) : "memory" ); } #define a_barrier a_barrier @@ -102,8 +71,31 @@ static inline void a_barrier() __asm__ __volatile__( "" : : : "memory" ); } +#define a_pause a_pause +static inline void a_spin() +{ + __asm__ __volatile__( "pause" : : : "memory" ); +} + #define a_crash a_crash static inline void a_crash() { __asm__ __volatile__( "hlt" : : : "memory" ); } + +#define a_ctz_64 a_ctz_64 +static inline int a_ctz_64(uint64_t x) +{ + int r; + __asm__( "bsf %1,%0 ; jnz 1f ; bsf %2,%0 ; add $32,%0\n1:" + : "=&r"(r) : "r"((unsigned)x), "r"((unsigned)(x>>32)) ); + return r; +} + +#define a_ctz_l a_ctz_l +static inline int a_ctz_l(unsigned long x) +{ + long r; + __asm__( "bsf %1,%0" : "=r"(r) : "r"(x) ); + return r; +} -- GitLab