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Diffstat (limited to 'arch/arm64/include/asm/atomic_ll_sc.h')
| -rw-r--r-- | arch/arm64/include/asm/atomic_ll_sc.h | 247 |
1 files changed, 247 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/atomic_ll_sc.h b/arch/arm64/include/asm/atomic_ll_sc.h new file mode 100644 index 000000000000..b3b5c4ae3800 --- /dev/null +++ b/arch/arm64/include/asm/atomic_ll_sc.h @@ -0,0 +1,247 @@ +/* + * Based on arch/arm/include/asm/atomic.h + * + * Copyright (C) 1996 Russell King. + * Copyright (C) 2002 Deep Blue Solutions Ltd. + * Copyright (C) 2012 ARM Ltd. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + */ + +#ifndef __ASM_ATOMIC_LL_SC_H +#define __ASM_ATOMIC_LL_SC_H + +#ifndef __ARM64_IN_ATOMIC_IMPL +#error "please don't include this file directly" +#endif + +/* + * AArch64 UP and SMP safe atomic ops. We use load exclusive and + * store exclusive to ensure that these are atomic. We may loop + * to ensure that the update happens. + * + * NOTE: these functions do *not* follow the PCS and must explicitly + * save any clobbered registers other than x0 (regardless of return + * value). This is achieved through -fcall-saved-* compiler flags for + * this file, which unfortunately don't work on a per-function basis + * (the optimize attribute silently ignores these options). + */ + +#define ATOMIC_OP(op, asm_op) \ +__LL_SC_INLINE void \ +__LL_SC_PREFIX(atomic_##op(int i, atomic_t *v)) \ +{ \ + unsigned long tmp; \ + int result; \ + \ + asm volatile("// atomic_" #op "\n" \ +" prfm pstl1strm, %2\n" \ +"1: ldxr %w0, %2\n" \ +" " #asm_op " %w0, %w0, %w3\n" \ +" stxr %w1, %w0, %2\n" \ +" cbnz %w1, 1b" \ + : "=&r" (result), "=&r" (tmp), "+Q" (v->counter) \ + : "Ir" (i)); \ +} \ +__LL_SC_EXPORT(atomic_##op); + +#define ATOMIC_OP_RETURN(op, asm_op) \ +__LL_SC_INLINE int \ +__LL_SC_PREFIX(atomic_##op##_return(int i, atomic_t *v)) \ +{ \ + unsigned long tmp; \ + int result; \ + \ + asm volatile("// atomic_" #op "_return\n" \ +" prfm pstl1strm, %2\n" \ +"1: ldxr %w0, %2\n" \ +" " #asm_op " %w0, %w0, %w3\n" \ +" stlxr %w1, %w0, %2\n" \ +" cbnz %w1, 1b" \ + : "=&r" (result), "=&r" (tmp), "+Q" (v->counter) \ + : "Ir" (i) \ + : "memory"); \ + \ + smp_mb(); \ + return result; \ +} \ +__LL_SC_EXPORT(atomic_##op##_return); + +#define ATOMIC_OPS(op, asm_op) \ + ATOMIC_OP(op, asm_op) \ + ATOMIC_OP_RETURN(op, asm_op) + +ATOMIC_OPS(add, add) +ATOMIC_OPS(sub, sub) + +ATOMIC_OP(and, and) +ATOMIC_OP(andnot, bic) +ATOMIC_OP(or, orr) +ATOMIC_OP(xor, eor) + +#undef ATOMIC_OPS +#undef ATOMIC_OP_RETURN +#undef ATOMIC_OP + +#define ATOMIC64_OP(op, asm_op) \ +__LL_SC_INLINE void \ +__LL_SC_PREFIX(atomic64_##op(long i, atomic64_t *v)) \ +{ \ + long result; \ + unsigned long tmp; \ + \ + asm volatile("// atomic64_" #op "\n" \ +" prfm pstl1strm, %2\n" \ +"1: ldxr %0, %2\n" \ +" " #asm_op " %0, %0, %3\n" \ +" stxr %w1, %0, %2\n" \ +" cbnz %w1, 1b" \ + : "=&r" (result), "=&r" (tmp), "+Q" (v->counter) \ + : "Ir" (i)); \ +} \ +__LL_SC_EXPORT(atomic64_##op); + +#define ATOMIC64_OP_RETURN(op, asm_op) \ +__LL_SC_INLINE long \ +__LL_SC_PREFIX(atomic64_##op##_return(long i, atomic64_t *v)) \ +{ \ + long result; \ + unsigned long tmp; \ + \ + asm volatile("// atomic64_" #op "_return\n" \ +" prfm pstl1strm, %2\n" \ +"1: ldxr %0, %2\n" \ +" " #asm_op " %0, %0, %3\n" \ +" stlxr %w1, %0, %2\n" \ +" cbnz %w1, 1b" \ + : "=&r" (result), "=&r" (tmp), "+Q" (v->counter) \ + : "Ir" (i) \ + : "memory"); \ + \ + smp_mb(); \ + return result; \ +} \ +__LL_SC_EXPORT(atomic64_##op##_return); + +#define ATOMIC64_OPS(op, asm_op) \ + ATOMIC64_OP(op, asm_op) \ + ATOMIC64_OP_RETURN(op, asm_op) + +ATOMIC64_OPS(add, add) +ATOMIC64_OPS(sub, sub) + +ATOMIC64_OP(and, and) +ATOMIC64_OP(andnot, bic) +ATOMIC64_OP(or, orr) +ATOMIC64_OP(xor, eor) + +#undef ATOMIC64_OPS +#undef ATOMIC64_OP_RETURN +#undef ATOMIC64_OP + +__LL_SC_INLINE long +__LL_SC_PREFIX(atomic64_dec_if_positive(atomic64_t *v)) +{ + long result; + unsigned long tmp; + + asm volatile("// atomic64_dec_if_positive\n" +" prfm pstl1strm, %2\n" +"1: ldxr %0, %2\n" +" subs %0, %0, #1\n" +" b.lt 2f\n" +" stlxr %w1, %0, %2\n" +" cbnz %w1, 1b\n" +" dmb ish\n" +"2:" + : "=&r" (result), "=&r" (tmp), "+Q" (v->counter) + : + : "cc", "memory"); + + return result; +} +__LL_SC_EXPORT(atomic64_dec_if_positive); + +#define __CMPXCHG_CASE(w, sz, name, mb, rel, cl) \ +__LL_SC_INLINE unsigned long \ +__LL_SC_PREFIX(__cmpxchg_case_##name(volatile void *ptr, \ + unsigned long old, \ + unsigned long new)) \ +{ \ + unsigned long tmp, oldval; \ + \ + asm volatile( \ + " prfm pstl1strm, %[v]\n" \ + "1: ldxr" #sz "\t%" #w "[oldval], %[v]\n" \ + " eor %" #w "[tmp], %" #w "[oldval], %" #w "[old]\n" \ + " cbnz %" #w "[tmp], 2f\n" \ + " st" #rel "xr" #sz "\t%w[tmp], %" #w "[new], %[v]\n" \ + " cbnz %w[tmp], 1b\n" \ + " " #mb "\n" \ + " mov %" #w "[oldval], %" #w "[old]\n" \ + "2:" \ + : [tmp] "=&r" (tmp), [oldval] "=&r" (oldval), \ + [v] "+Q" (*(unsigned long *)ptr) \ + : [old] "Lr" (old), [new] "r" (new) \ + : cl); \ + \ + return oldval; \ +} \ +__LL_SC_EXPORT(__cmpxchg_case_##name); + +__CMPXCHG_CASE(w, b, 1, , , ) +__CMPXCHG_CASE(w, h, 2, , , ) +__CMPXCHG_CASE(w, , 4, , , ) +__CMPXCHG_CASE( , , 8, , , ) +__CMPXCHG_CASE(w, b, mb_1, dmb ish, l, "memory") +__CMPXCHG_CASE(w, h, mb_2, dmb ish, l, "memory") +__CMPXCHG_CASE(w, , mb_4, dmb ish, l, "memory") +__CMPXCHG_CASE( , , mb_8, dmb ish, l, "memory") + +#undef __CMPXCHG_CASE + +#define __CMPXCHG_DBL(name, mb, rel, cl) \ +__LL_SC_INLINE int \ +__LL_SC_PREFIX(__cmpxchg_double##name(unsigned long old1, \ + unsigned long old2, \ + unsigned long new1, \ + unsigned long new2, \ + volatile void *ptr)) \ +{ \ + unsigned long tmp, ret; \ + \ + asm volatile("// __cmpxchg_double" #name "\n" \ + " prfm pstl1strm, %2\n" \ + "1: ldxp %0, %1, %2\n" \ + " eor %0, %0, %3\n" \ + " eor %1, %1, %4\n" \ + " orr %1, %0, %1\n" \ + " cbnz %1, 2f\n" \ + " st" #rel "xp %w0, %5, %6, %2\n" \ + " cbnz %w0, 1b\n" \ + " " #mb "\n" \ + "2:" \ + : "=&r" (tmp), "=&r" (ret), "+Q" (*(unsigned long *)ptr) \ + : "r" (old1), "r" (old2), "r" (new1), "r" (new2) \ + : cl); \ + \ + return ret; \ +} \ +__LL_SC_EXPORT(__cmpxchg_double##name); + +__CMPXCHG_DBL( , , , ) +__CMPXCHG_DBL(_mb, dmb ish, l, "memory") + +#undef __CMPXCHG_DBL + +#endif /* __ASM_ATOMIC_LL_SC_H */ |