diff options
Diffstat (limited to 'arch/arc/include/asm/atomic.h')
| -rw-r--r-- | arch/arc/include/asm/atomic.h | 93 |
1 files changed, 78 insertions, 15 deletions
diff --git a/arch/arc/include/asm/atomic.h b/arch/arc/include/asm/atomic.h index 9917a45fc430..87d18ae53115 100644 --- a/arch/arc/include/asm/atomic.h +++ b/arch/arc/include/asm/atomic.h @@ -23,36 +23,83 @@ #define atomic_set(v, i) (((v)->counter) = (i)) +#ifdef CONFIG_ARC_STAR_9000923308 + +#define SCOND_FAIL_RETRY_VAR_DEF \ + unsigned int delay = 1, tmp; \ + +#define SCOND_FAIL_RETRY_ASM \ + " bz 4f \n" \ + " ; --- scond fail delay --- \n" \ + " mov %[tmp], %[delay] \n" /* tmp = delay */ \ + "2: brne.d %[tmp], 0, 2b \n" /* while (tmp != 0) */ \ + " sub %[tmp], %[tmp], 1 \n" /* tmp-- */ \ + " rol %[delay], %[delay] \n" /* delay *= 2 */ \ + " b 1b \n" /* start over */ \ + "4: ; --- success --- \n" \ + +#define SCOND_FAIL_RETRY_VARS \ + ,[delay] "+&r" (delay),[tmp] "=&r" (tmp) \ + +#else /* !CONFIG_ARC_STAR_9000923308 */ + +#define SCOND_FAIL_RETRY_VAR_DEF + +#define SCOND_FAIL_RETRY_ASM \ + " bnz 1b \n" \ + +#define SCOND_FAIL_RETRY_VARS + +#endif + #define ATOMIC_OP(op, c_op, asm_op) \ static inline void atomic_##op(int i, atomic_t *v) \ { \ - unsigned int temp; \ + unsigned int val; \ + SCOND_FAIL_RETRY_VAR_DEF \ \ __asm__ __volatile__( \ - "1: llock %0, [%1] \n" \ - " " #asm_op " %0, %0, %2 \n" \ - " scond %0, [%1] \n" \ - " bnz 1b \n" \ - : "=&r"(temp) /* Early clobber, to prevent reg reuse */ \ - : "r"(&v->counter), "ir"(i) \ + "1: llock %[val], [%[ctr]] \n" \ + " " #asm_op " %[val], %[val], %[i] \n" \ + " scond %[val], [%[ctr]] \n" \ + " \n" \ + SCOND_FAIL_RETRY_ASM \ + \ + : [val] "=&r" (val) /* Early clobber to prevent reg reuse */ \ + SCOND_FAIL_RETRY_VARS \ + : [ctr] "r" (&v->counter), /* Not "m": llock only supports reg direct addr mode */ \ + [i] "ir" (i) \ : "cc"); \ } \ #define ATOMIC_OP_RETURN(op, c_op, asm_op) \ static inline int atomic_##op##_return(int i, atomic_t *v) \ { \ - unsigned int temp; \ + unsigned int val; \ + SCOND_FAIL_RETRY_VAR_DEF \ + \ + /* \ + * Explicit full memory barrier needed before/after as \ + * LLOCK/SCOND thmeselves don't provide any such semantics \ + */ \ + smp_mb(); \ \ __asm__ __volatile__( \ - "1: llock %0, [%1] \n" \ - " " #asm_op " %0, %0, %2 \n" \ - " scond %0, [%1] \n" \ - " bnz 1b \n" \ - : "=&r"(temp) \ - : "r"(&v->counter), "ir"(i) \ + "1: llock %[val], [%[ctr]] \n" \ + " " #asm_op " %[val], %[val], %[i] \n" \ + " scond %[val], [%[ctr]] \n" \ + " \n" \ + SCOND_FAIL_RETRY_ASM \ + \ + : [val] "=&r" (val) \ + SCOND_FAIL_RETRY_VARS \ + : [ctr] "r" (&v->counter), \ + [i] "ir" (i) \ : "cc"); \ \ - return temp; \ + smp_mb(); \ + \ + return val; \ } #else /* !CONFIG_ARC_HAS_LLSC */ @@ -105,6 +152,9 @@ static inline int atomic_##op##_return(int i, atomic_t *v) \ unsigned long flags; \ unsigned long temp; \ \ + /* \ + * spin lock/unlock provides the needed smp_mb() before/after \ + */ \ atomic_ops_lock(flags); \ temp = v->counter; \ temp c_op i; \ @@ -129,6 +179,9 @@ ATOMIC_OP(and, &=, and) #undef ATOMIC_OPS #undef ATOMIC_OP_RETURN #undef ATOMIC_OP +#undef SCOND_FAIL_RETRY_VAR_DEF +#undef SCOND_FAIL_RETRY_ASM +#undef SCOND_FAIL_RETRY_VARS /** * __atomic_add_unless - add unless the number is a given value @@ -142,9 +195,19 @@ ATOMIC_OP(and, &=, and) #define __atomic_add_unless(v, a, u) \ ({ \ int c, old; \ + \ + /* \ + * Explicit full memory barrier needed before/after as \ + * LLOCK/SCOND thmeselves don't provide any such semantics \ + */ \ + smp_mb(); \ + \ c = atomic_read(v); \ while (c != (u) && (old = atomic_cmpxchg((v), c, c + (a))) != c)\ c = old; \ + \ + smp_mb(); \ + \ c; \ }) |