| /* |
| * 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" \ |
| "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" \ |
| "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 |
| |
| __LL_SC_INLINE int |
| __LL_SC_PREFIX(atomic_cmpxchg(atomic_t *ptr, int old, int new)) |
| { |
| unsigned long tmp; |
| int oldval; |
| |
| smp_mb(); |
| |
| asm volatile("// atomic_cmpxchg\n" |
| "1: ldxr %w1, %2\n" |
| " cmp %w1, %w3\n" |
| " b.ne 2f\n" |
| " stxr %w0, %w4, %2\n" |
| " cbnz %w0, 1b\n" |
| "2:" |
| : "=&r" (tmp), "=&r" (oldval), "+Q" (ptr->counter) |
| : "Ir" (old), "r" (new) |
| : "cc"); |
| |
| smp_mb(); |
| return oldval; |
| } |
| __LL_SC_EXPORT(atomic_cmpxchg); |
| |
| #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" \ |
| "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" \ |
| "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_cmpxchg(atomic64_t *ptr, long old, long new)) |
| { |
| long oldval; |
| unsigned long res; |
| |
| smp_mb(); |
| |
| asm volatile("// atomic64_cmpxchg\n" |
| "1: ldxr %1, %2\n" |
| " cmp %1, %3\n" |
| " b.ne 2f\n" |
| " stxr %w0, %4, %2\n" |
| " cbnz %w0, 1b\n" |
| "2:" |
| : "=&r" (res), "=&r" (oldval), "+Q" (ptr->counter) |
| : "Ir" (old), "r" (new) |
| : "cc"); |
| |
| smp_mb(); |
| return oldval; |
| } |
| __LL_SC_EXPORT(atomic64_cmpxchg); |
| |
| __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" |
| "1: ldxr %0, %2\n" |
| " subs %0, %0, #1\n" |
| " b.mi 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, 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( \ |
| " " #mb "\n" \ |
| "1: ldxr" #sz "\t%" #w "[oldval], %[v]\n" \ |
| " eor %" #w "[tmp], %" #w "[oldval], %" #w "[old]\n" \ |
| " cbnz %" #w "[tmp], 2f\n" \ |
| " stxr" #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, "memory") |
| __CMPXCHG_CASE(w, h, mb_2, dmb ish, "memory") |
| __CMPXCHG_CASE(w, , mb_4, dmb ish, "memory") |
| __CMPXCHG_CASE( , , mb_8, dmb ish, "memory") |
| |
| #undef __CMPXCHG_CASE |
| |
| #endif /* __ASM_ATOMIC_LL_SC_H */ |