diff options
Diffstat (limited to 'include/asm-alpha/system.h')
| -rw-r--r-- | include/asm-alpha/system.h | 58 |
1 files changed, 41 insertions, 17 deletions
diff --git a/include/asm-alpha/system.h b/include/asm-alpha/system.h index 6328750e1..b97d0c5b6 100644 --- a/include/asm-alpha/system.h +++ b/include/asm-alpha/system.h @@ -137,12 +137,19 @@ __asm__ __volatile__("mb": : :"memory") #define wmb() \ __asm__ __volatile__("wmb": : :"memory") +#ifdef CONFIG_SMP +#define smp_mb() mb() +#define smp_rmb() rmb() +#define smp_wmb() wmb() +#else +#define smp_mb() barrier() +#define smp_rmb() barrier() +#define smp_wmb() barrier() +#endif + #define set_mb(var, value) \ do { var = value; mb(); } while (0) -#define set_rmb(var, value) \ -do { var = value; rmb(); } while (0) - #define set_wmb(var, value) \ do { var = value; wmb(); } while (0) @@ -284,11 +291,11 @@ extern int __min_ipl; #define getipl() (rdps() & 7) #define setipl(ipl) ((void) swpipl(ipl)) -#define __cli() setipl(IPL_MAX) -#define __sti() setipl(IPL_MIN) +#define __cli() do { setipl(IPL_MAX); barrier(); } while(0) +#define __sti() do { barrier(); setipl(IPL_MIN); } while(0) #define __save_flags(flags) ((flags) = rdps()) -#define __save_and_cli(flags) ((flags) = swpipl(IPL_MAX)) -#define __restore_flags(flags) setipl(flags) +#define __save_and_cli(flags) do { (flags) = swpipl(IPL_MAX); barrier(); } while(0) +#define __restore_flags(flags) do { barrier(); setipl(flags); barrier(); } while(0) #define local_irq_save(flags) __save_and_cli(flags) #define local_irq_restore(flags) __restore_flags(flags) @@ -344,6 +351,8 @@ extern void __global_restore_flags(unsigned long flags); /* * Atomic exchange. + * Since it can be used to implement critical sections + * it must clobber "memory" (also for interrupts in UP). */ extern __inline__ unsigned long @@ -352,16 +361,18 @@ __xchg_u32(volatile int *m, unsigned long val) unsigned long dummy; __asm__ __volatile__( - "1: ldl_l %0,%2\n" + "1: ldl_l %0,%4\n" " bis $31,%3,%1\n" " stl_c %1,%2\n" " beq %1,2f\n" +#ifdef CONFIG_SMP " mb\n" +#endif ".subsection 2\n" "2: br 1b\n" ".previous" : "=&r" (val), "=&r" (dummy), "=m" (*m) - : "rI" (val), "m" (*m)); + : "rI" (val), "m" (*m) : "memory"); return val; } @@ -372,16 +383,18 @@ __xchg_u64(volatile long *m, unsigned long val) unsigned long dummy; __asm__ __volatile__( - "1: ldq_l %0,%2\n" + "1: ldq_l %0,%4\n" " bis $31,%3,%1\n" " stq_c %1,%2\n" " beq %1,2f\n" +#ifdef CONFIG_SMP " mb\n" +#endif ".subsection 2\n" "2: br 1b\n" ".previous" : "=&r" (val), "=&r" (dummy), "=m" (*m) - : "rI" (val), "m" (*m)); + : "rI" (val), "m" (*m) : "memory"); return val; } @@ -416,6 +429,11 @@ __xchg(volatile void *ptr, unsigned long x, int size) * Atomic compare and exchange. Compare OLD with MEM, if identical, * store NEW in MEM. Return the initial value in MEM. Success is * indicated by comparing RETURN with OLD. + * + * The memory barrier should be placed in SMP only when we actually + * make the change. If we don't change anything (so if the returned + * prev is equal to old) then we aren't acquiring anything new and + * we don't need any memory barrier as far I can tell. */ #define __HAVE_ARCH_CMPXCHG 1 @@ -426,18 +444,21 @@ __cmpxchg_u32(volatile int *m, int old, int new) unsigned long prev, cmp; __asm__ __volatile__( - "1: ldl_l %0,%2\n" + "1: ldl_l %0,%5\n" " cmpeq %0,%3,%1\n" " beq %1,2f\n" " mov %4,%1\n" " stl_c %1,%2\n" " beq %1,3f\n" - "2: mb\n" +#ifdef CONFIG_SMP + " mb\n" +#endif + "2:\n" ".subsection 2\n" "3: br 1b\n" ".previous" : "=&r"(prev), "=&r"(cmp), "=m"(*m) - : "r"((long) old), "r"(new), "m"(*m)); + : "r"((long) old), "r"(new), "m"(*m) : "memory"); return prev; } @@ -448,18 +469,21 @@ __cmpxchg_u64(volatile long *m, unsigned long old, unsigned long new) unsigned long prev, cmp; __asm__ __volatile__( - "1: ldq_l %0,%2\n" + "1: ldq_l %0,%5\n" " cmpeq %0,%3,%1\n" " beq %1,2f\n" " mov %4,%1\n" " stq_c %1,%2\n" " beq %1,3f\n" - "2: mb\n" +#ifdef CONFIG_SMP + " mb\n" +#endif + "2:\n" ".subsection 2\n" "3: br 1b\n" ".previous" : "=&r"(prev), "=&r"(cmp), "=m"(*m) - : "r"((long) old), "r"(new), "m"(*m)); + : "r"((long) old), "r"(new), "m"(*m) : "memory"); return prev; } |