From c275f76bb4ce16fd0205da1e15f31b875013678e Mon Sep 17 00:00:00 2001 From: Will Deacon Date: Tue, 3 Feb 2015 11:26:53 +0000 Subject: [PATCH] arm64: atomics: move ll/sc atomics into separate header file In preparation for the Large System Extension (LSE) atomic instructions introduced by ARM v8.1, move the current exclusive load/store (LL/SC) atomics into their own header file. Reviewed-by: Steve Capper Reviewed-by: Catalin Marinas Signed-off-by: Will Deacon --- arch/arm64/include/asm/atomic.h | 180 +-------------------- arch/arm64/include/asm/atomic_ll_sc.h | 215 ++++++++++++++++++++++++++ 2 files changed, 221 insertions(+), 174 deletions(-) create mode 100644 arch/arm64/include/asm/atomic_ll_sc.h diff --git a/arch/arm64/include/asm/atomic.h b/arch/arm64/include/asm/atomic.h index 866a71fca9a3..632c47064722 100644 --- a/arch/arm64/include/asm/atomic.h +++ b/arch/arm64/include/asm/atomic.h @@ -30,6 +30,8 @@ #ifdef __KERNEL__ +#include + /* * On ARM, ordinary assignment (str instruction) doesn't clear the local * strex/ldrex monitor on some implementations. The reason we can use it for @@ -38,86 +40,6 @@ #define atomic_read(v) ACCESS_ONCE((v)->counter) #define atomic_set(v,i) (((v)->counter) = (i)) -/* - * 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. - */ - -#define ATOMIC_OP(op, asm_op) \ -static inline void 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)); \ -} \ - -#define ATOMIC_OP_RETURN(op, asm_op) \ -static inline int 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; \ -} - -#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) - -#define atomic_andnot atomic_andnot - -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 - -static inline int 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; -} - #define atomic_xchg(v, new) (xchg(&((v)->counter), new)) static inline int __atomic_add_unless(atomic_t *v, int a, int u) @@ -141,6 +63,8 @@ static inline int __atomic_add_unless(atomic_t *v, int a, int u) #define atomic_add_negative(i,v) (atomic_add_return(i, v) < 0) +#define atomic_andnot atomic_andnot + /* * 64-bit atomic operations. */ @@ -149,102 +73,8 @@ static inline int __atomic_add_unless(atomic_t *v, int a, int u) #define atomic64_read(v) ACCESS_ONCE((v)->counter) #define atomic64_set(v,i) (((v)->counter) = (i)) -#define ATOMIC64_OP(op, asm_op) \ -static inline void 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)); \ -} \ - -#define ATOMIC64_OP_RETURN(op, asm_op) \ -static inline long 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; \ -} - -#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) - -#define atomic64_andnot atomic64_andnot - -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 - -static inline long 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; -} - #define atomic64_xchg(v, new) (xchg(&((v)->counter), new)) -static inline long 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; -} - static inline int atomic64_add_unless(atomic64_t *v, long a, long u) { long c, old; @@ -266,5 +96,7 @@ static inline int atomic64_add_unless(atomic64_t *v, long a, long u) #define atomic64_dec_and_test(v) (atomic64_dec_return((v)) == 0) #define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1LL, 0LL) +#define atomic64_andnot atomic64_andnot + #endif #endif 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..66e992a58f6b --- /dev/null +++ b/arch/arm64/include/asm/atomic_ll_sc.h @@ -0,0 +1,215 @@ +/* + * 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 . + */ + +#ifndef __ASM_ATOMIC_LL_SC_H +#define __ASM_ATOMIC_LL_SC_H + +/* + * 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). + */ + +#ifndef __LL_SC_INLINE +#define __LL_SC_INLINE static inline +#endif + +#ifndef __LL_SC_PREFIX +#define __LL_SC_PREFIX(x) x +#endif + +#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)); \ +} \ + +#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; \ +} + +#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; +} + +#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)); \ +} \ + +#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; \ +} + +#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_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; +} + +#endif /* __ASM_ATOMIC_LL_SC_H */ -- 2.20.1