diff options
Diffstat (limited to 'arch/arc/include/asm/bitops.h')
| -rw-r--r-- | arch/arc/include/asm/bitops.h | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/arch/arc/include/asm/bitops.h b/arch/arc/include/asm/bitops.h index 829a8a2e9704..dd03fd931bb7 100644 --- a/arch/arc/include/asm/bitops.h +++ b/arch/arc/include/asm/bitops.h @@ -117,6 +117,12 @@ static inline int test_and_set_bit(unsigned long nr, volatile unsigned long *m) if (__builtin_constant_p(nr)) nr &= 0x1f; + /* + * Explicit full memory barrier needed before/after as + * LLOCK/SCOND themselves don't provide any such semantics + */ + smp_mb(); + __asm__ __volatile__( "1: llock %0, [%2] \n" " bset %1, %0, %3 \n" @@ -126,6 +132,8 @@ static inline int test_and_set_bit(unsigned long nr, volatile unsigned long *m) : "r"(m), "ir"(nr) : "cc"); + smp_mb(); + return (old & (1 << nr)) != 0; } @@ -139,6 +147,8 @@ test_and_clear_bit(unsigned long nr, volatile unsigned long *m) if (__builtin_constant_p(nr)) nr &= 0x1f; + smp_mb(); + __asm__ __volatile__( "1: llock %0, [%2] \n" " bclr %1, %0, %3 \n" @@ -148,6 +158,8 @@ test_and_clear_bit(unsigned long nr, volatile unsigned long *m) : "r"(m), "ir"(nr) : "cc"); + smp_mb(); + return (old & (1 << nr)) != 0; } @@ -161,6 +173,8 @@ test_and_change_bit(unsigned long nr, volatile unsigned long *m) if (__builtin_constant_p(nr)) nr &= 0x1f; + smp_mb(); + __asm__ __volatile__( "1: llock %0, [%2] \n" " bxor %1, %0, %3 \n" @@ -170,6 +184,8 @@ test_and_change_bit(unsigned long nr, volatile unsigned long *m) : "r"(m), "ir"(nr) : "cc"); + smp_mb(); + return (old & (1 << nr)) != 0; } @@ -249,6 +265,9 @@ static inline int test_and_set_bit(unsigned long nr, volatile unsigned long *m) if (__builtin_constant_p(nr)) nr &= 0x1f; + /* + * spin lock/unlock provide the needed smp_mb() before/after + */ bitops_lock(flags); old = *m; |