diff options
Diffstat (limited to 'arch/arc/include/asm/atomic64-arcv2.h')
| -rw-r--r-- | arch/arc/include/asm/atomic64-arcv2.h | 235 |
1 files changed, 235 insertions, 0 deletions
diff --git a/arch/arc/include/asm/atomic64-arcv2.h b/arch/arc/include/asm/atomic64-arcv2.h new file mode 100644 index 0000000000..9b5791b854 --- /dev/null +++ b/arch/arc/include/asm/atomic64-arcv2.h @@ -0,0 +1,235 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ + +/* + * ARCv2 supports 64-bit exclusive load (LLOCKD) / store (SCONDD) + * - The address HAS to be 64-bit aligned + */ + +#ifndef _ASM_ARC_ATOMIC64_ARCV2_H +#define _ASM_ARC_ATOMIC64_ARCV2_H + +typedef struct { + s64 __aligned(8) counter; +} atomic64_t; + +#define ATOMIC64_INIT(a) { (a) } + +static inline s64 arch_atomic64_read(const atomic64_t *v) +{ + s64 val; + + __asm__ __volatile__( + " ldd %0, [%1] \n" + : "=r"(val) + : "r"(&v->counter)); + + return val; +} + +static inline void arch_atomic64_set(atomic64_t *v, s64 a) +{ + /* + * This could have been a simple assignment in "C" but would need + * explicit volatile. Otherwise gcc optimizers could elide the store + * which borked atomic64 self-test + * In the inline asm version, memory clobber needed for exact same + * reason, to tell gcc about the store. + * + * This however is not needed for sibling atomic64_add() etc since both + * load/store are explicitly done in inline asm. As long as API is used + * for each access, gcc has no way to optimize away any load/store + */ + __asm__ __volatile__( + " std %0, [%1] \n" + : + : "r"(a), "r"(&v->counter) + : "memory"); +} + +#define ATOMIC64_OP(op, op1, op2) \ +static inline void arch_atomic64_##op(s64 a, atomic64_t *v) \ +{ \ + s64 val; \ + \ + __asm__ __volatile__( \ + "1: \n" \ + " llockd %0, [%1] \n" \ + " " #op1 " %L0, %L0, %L2 \n" \ + " " #op2 " %H0, %H0, %H2 \n" \ + " scondd %0, [%1] \n" \ + " bnz 1b \n" \ + : "=&r"(val) \ + : "r"(&v->counter), "ir"(a) \ + : "cc", "memory"); \ +} \ + +#define ATOMIC64_OP_RETURN(op, op1, op2) \ +static inline s64 arch_atomic64_##op##_return_relaxed(s64 a, atomic64_t *v) \ +{ \ + s64 val; \ + \ + __asm__ __volatile__( \ + "1: \n" \ + " llockd %0, [%1] \n" \ + " " #op1 " %L0, %L0, %L2 \n" \ + " " #op2 " %H0, %H0, %H2 \n" \ + " scondd %0, [%1] \n" \ + " bnz 1b \n" \ + : [val] "=&r"(val) \ + : "r"(&v->counter), "ir"(a) \ + : "cc", "memory"); \ + \ + return val; \ +} + +#define arch_atomic64_add_return_relaxed arch_atomic64_add_return_relaxed +#define arch_atomic64_sub_return_relaxed arch_atomic64_sub_return_relaxed + +#define ATOMIC64_FETCH_OP(op, op1, op2) \ +static inline s64 arch_atomic64_fetch_##op##_relaxed(s64 a, atomic64_t *v) \ +{ \ + s64 val, orig; \ + \ + __asm__ __volatile__( \ + "1: \n" \ + " llockd %0, [%2] \n" \ + " " #op1 " %L1, %L0, %L3 \n" \ + " " #op2 " %H1, %H0, %H3 \n" \ + " scondd %1, [%2] \n" \ + " bnz 1b \n" \ + : "=&r"(orig), "=&r"(val) \ + : "r"(&v->counter), "ir"(a) \ + : "cc", "memory"); \ + \ + return orig; \ +} + +#define arch_atomic64_fetch_add_relaxed arch_atomic64_fetch_add_relaxed +#define arch_atomic64_fetch_sub_relaxed arch_atomic64_fetch_sub_relaxed + +#define arch_atomic64_fetch_and_relaxed arch_atomic64_fetch_and_relaxed +#define arch_atomic64_fetch_andnot_relaxed arch_atomic64_fetch_andnot_relaxed +#define arch_atomic64_fetch_or_relaxed arch_atomic64_fetch_or_relaxed +#define arch_atomic64_fetch_xor_relaxed arch_atomic64_fetch_xor_relaxed + +#define ATOMIC64_OPS(op, op1, op2) \ + ATOMIC64_OP(op, op1, op2) \ + ATOMIC64_OP_RETURN(op, op1, op2) \ + ATOMIC64_FETCH_OP(op, op1, op2) + +ATOMIC64_OPS(add, add.f, adc) +ATOMIC64_OPS(sub, sub.f, sbc) + +#undef ATOMIC64_OPS +#define ATOMIC64_OPS(op, op1, op2) \ + ATOMIC64_OP(op, op1, op2) \ + ATOMIC64_FETCH_OP(op, op1, op2) + +ATOMIC64_OPS(and, and, and) +ATOMIC64_OPS(andnot, bic, bic) +ATOMIC64_OPS(or, or, or) +ATOMIC64_OPS(xor, xor, xor) + +#define arch_atomic64_andnot arch_atomic64_andnot + +#undef ATOMIC64_OPS +#undef ATOMIC64_FETCH_OP +#undef ATOMIC64_OP_RETURN +#undef ATOMIC64_OP + +static inline s64 +arch_atomic64_cmpxchg(atomic64_t *ptr, s64 expected, s64 new) +{ + s64 prev; + + smp_mb(); + + __asm__ __volatile__( + "1: llockd %0, [%1] \n" + " brne %L0, %L2, 2f \n" + " brne %H0, %H2, 2f \n" + " scondd %3, [%1] \n" + " bnz 1b \n" + "2: \n" + : "=&r"(prev) + : "r"(ptr), "ir"(expected), "r"(new) + : "cc"); /* memory clobber comes from smp_mb() */ + + smp_mb(); + + return prev; +} +#define arch_atomic64_cmpxchg arch_atomic64_cmpxchg + +static inline s64 arch_atomic64_xchg(atomic64_t *ptr, s64 new) +{ + s64 prev; + + smp_mb(); + + __asm__ __volatile__( + "1: llockd %0, [%1] \n" + " scondd %2, [%1] \n" + " bnz 1b \n" + "2: \n" + : "=&r"(prev) + : "r"(ptr), "r"(new) + : "cc"); /* memory clobber comes from smp_mb() */ + + smp_mb(); + + return prev; +} +#define arch_atomic64_xchg arch_atomic64_xchg + +static inline s64 arch_atomic64_dec_if_positive(atomic64_t *v) +{ + s64 val; + + smp_mb(); + + __asm__ __volatile__( + "1: llockd %0, [%1] \n" + " sub.f %L0, %L0, 1 # w0 - 1, set C on borrow\n" + " sub.c %H0, %H0, 1 # if C set, w1 - 1\n" + " brlt %H0, 0, 2f \n" + " scondd %0, [%1] \n" + " bnz 1b \n" + "2: \n" + : "=&r"(val) + : "r"(&v->counter) + : "cc"); /* memory clobber comes from smp_mb() */ + + smp_mb(); + + return val; +} +#define arch_atomic64_dec_if_positive arch_atomic64_dec_if_positive + +static inline s64 arch_atomic64_fetch_add_unless(atomic64_t *v, s64 a, s64 u) +{ + s64 old, temp; + + smp_mb(); + + __asm__ __volatile__( + "1: llockd %0, [%2] \n" + " brne %L0, %L4, 2f # continue to add since v != u \n" + " breq.d %H0, %H4, 3f # return since v == u \n" + "2: \n" + " add.f %L1, %L0, %L3 \n" + " adc %H1, %H0, %H3 \n" + " scondd %1, [%2] \n" + " bnz 1b \n" + "3: \n" + : "=&r"(old), "=&r" (temp) + : "r"(&v->counter), "r"(a), "r"(u) + : "cc"); /* memory clobber comes from smp_mb() */ + + smp_mb(); + + return old; +} +#define arch_atomic64_fetch_add_unless arch_atomic64_fetch_add_unless + +#endif |