| /* |
| * arch/arm/include/asm/atomic.h |
| * |
| * Copyright (C) 1996 Russell King. |
| * Copyright (C) 2002 Deep Blue Solutions 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. |
| */ |
| #ifndef __ASM_ARM_ATOMIC_H |
| #define __ASM_ARM_ATOMIC_H |
| |
| #include <linux/compiler.h> |
| #include <linux/prefetch.h> |
| #include <linux/types.h> |
| #include <linux/irqflags.h> |
| #include <asm/barrier.h> |
| #include <asm/cmpxchg.h> |
| |
| #define ATOMIC_INIT(i) { (i) } |
| |
| #ifdef __KERNEL__ |
| |
| /* |
| * On ARM, ordinary assignment (str instruction) doesn't clear the local |
| * strex/ldrex monitor on some implementations. The reason we can use it for |
| * atomic_set() is the clrex or dummy strex done on every exception return. |
| */ |
| #define atomic_read(v) READ_ONCE((v)->counter) |
| #define atomic_set(v,i) WRITE_ONCE(((v)->counter), (i)) |
| |
| #if __LINUX_ARM_ARCH__ >= 6 |
| |
| /* |
| * ARMv6 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, c_op, asm_op) \ |
| static inline void atomic_##op(int i, atomic_t *v) \ |
| { \ |
| unsigned long tmp; \ |
| int result; \ |
| \ |
| prefetchw(&v->counter); \ |
| __asm__ __volatile__("@ atomic_" #op "\n" \ |
| "1: ldrex %0, [%3]\n" \ |
| " " #asm_op " %0, %0, %4\n" \ |
| " strex %1, %0, [%3]\n" \ |
| " teq %1, #0\n" \ |
| " bne 1b" \ |
| : "=&r" (result), "=&r" (tmp), "+Qo" (v->counter) \ |
| : "r" (&v->counter), "Ir" (i) \ |
| : "cc"); \ |
| } \ |
| |
| #define ATOMIC_OP_RETURN(op, c_op, asm_op) \ |
| static inline int atomic_##op##_return_relaxed(int i, atomic_t *v) \ |
| { \ |
| unsigned long tmp; \ |
| int result; \ |
| \ |
| prefetchw(&v->counter); \ |
| \ |
| __asm__ __volatile__("@ atomic_" #op "_return\n" \ |
| "1: ldrex %0, [%3]\n" \ |
| " " #asm_op " %0, %0, %4\n" \ |
| " strex %1, %0, [%3]\n" \ |
| " teq %1, #0\n" \ |
| " bne 1b" \ |
| : "=&r" (result), "=&r" (tmp), "+Qo" (v->counter) \ |
| : "r" (&v->counter), "Ir" (i) \ |
| : "cc"); \ |
| \ |
| return result; \ |
| } |
| |
| #define atomic_add_return_relaxed atomic_add_return_relaxed |
| #define atomic_sub_return_relaxed atomic_sub_return_relaxed |
| |
| static inline int atomic_cmpxchg_relaxed(atomic_t *ptr, int old, int new) |
| { |
| int oldval; |
| unsigned long res; |
| |
| prefetchw(&ptr->counter); |
| |
| do { |
| __asm__ __volatile__("@ atomic_cmpxchg\n" |
| "ldrex %1, [%3]\n" |
| "mov %0, #0\n" |
| "teq %1, %4\n" |
| "strexeq %0, %5, [%3]\n" |
| : "=&r" (res), "=&r" (oldval), "+Qo" (ptr->counter) |
| : "r" (&ptr->counter), "Ir" (old), "r" (new) |
| : "cc"); |
| } while (res); |
| |
| return oldval; |
| } |
| #define atomic_cmpxchg_relaxed atomic_cmpxchg_relaxed |
| |
| static inline int __atomic_add_unless(atomic_t *v, int a, int u) |
| { |
| int oldval, newval; |
| unsigned long tmp; |
| |
| smp_mb(); |
| prefetchw(&v->counter); |
| |
| __asm__ __volatile__ ("@ atomic_add_unless\n" |
| "1: ldrex %0, [%4]\n" |
| " teq %0, %5\n" |
| " beq 2f\n" |
| " add %1, %0, %6\n" |
| " strex %2, %1, [%4]\n" |
| " teq %2, #0\n" |
| " bne 1b\n" |
| "2:" |
| : "=&r" (oldval), "=&r" (newval), "=&r" (tmp), "+Qo" (v->counter) |
| : "r" (&v->counter), "r" (u), "r" (a) |
| : "cc"); |
| |
| if (oldval != u) |
| smp_mb(); |
| |
| return oldval; |
| } |
| |
| #else /* ARM_ARCH_6 */ |
| |
| #ifdef CONFIG_SMP |
| #error SMP not supported on pre-ARMv6 CPUs |
| #endif |
| |
| #define ATOMIC_OP(op, c_op, asm_op) \ |
| static inline void atomic_##op(int i, atomic_t *v) \ |
| { \ |
| unsigned long flags; \ |
| \ |
| raw_local_irq_save(flags); \ |
| v->counter c_op i; \ |
| raw_local_irq_restore(flags); \ |
| } \ |
| |
| #define ATOMIC_OP_RETURN(op, c_op, asm_op) \ |
| static inline int atomic_##op##_return(int i, atomic_t *v) \ |
| { \ |
| unsigned long flags; \ |
| int val; \ |
| \ |
| raw_local_irq_save(flags); \ |
| v->counter c_op i; \ |
| val = v->counter; \ |
| raw_local_irq_restore(flags); \ |
| \ |
| return val; \ |
| } |
| |
| static inline int atomic_cmpxchg(atomic_t *v, int old, int new) |
| { |
| int ret; |
| unsigned long flags; |
| |
| raw_local_irq_save(flags); |
| ret = v->counter; |
| if (likely(ret == old)) |
| v->counter = new; |
| raw_local_irq_restore(flags); |
| |
| return ret; |
| } |
| |
| static inline int __atomic_add_unless(atomic_t *v, int a, int u) |
| { |
| int c, old; |
| |
| c = atomic_read(v); |
| while (c != u && (old = atomic_cmpxchg((v), c, c + a)) != c) |
| c = old; |
| return c; |
| } |
| |
| #endif /* __LINUX_ARM_ARCH__ */ |
| |
| #define ATOMIC_OPS(op, c_op, asm_op) \ |
| ATOMIC_OP(op, c_op, asm_op) \ |
| ATOMIC_OP_RETURN(op, c_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 |
| |
| #define atomic_xchg(v, new) (xchg(&((v)->counter), new)) |
| |
| #define atomic_inc(v) atomic_add(1, v) |
| #define atomic_dec(v) atomic_sub(1, v) |
| |
| #define atomic_inc_and_test(v) (atomic_add_return(1, v) == 0) |
| #define atomic_dec_and_test(v) (atomic_sub_return(1, v) == 0) |
| #define atomic_inc_return_relaxed(v) (atomic_add_return_relaxed(1, v)) |
| #define atomic_dec_return_relaxed(v) (atomic_sub_return_relaxed(1, v)) |
| #define atomic_sub_and_test(i, v) (atomic_sub_return(i, v) == 0) |
| |
| #define atomic_add_negative(i,v) (atomic_add_return(i, v) < 0) |
| |
| #ifndef CONFIG_GENERIC_ATOMIC64 |
| typedef struct { |
| long long counter; |
| } atomic64_t; |
| |
| #define ATOMIC64_INIT(i) { (i) } |
| |
| #ifdef CONFIG_ARM_LPAE |
| static inline long long atomic64_read(const atomic64_t *v) |
| { |
| long long result; |
| |
| __asm__ __volatile__("@ atomic64_read\n" |
| " ldrd %0, %H0, [%1]" |
| : "=&r" (result) |
| : "r" (&v->counter), "Qo" (v->counter) |
| ); |
| |
| return result; |
| } |
| |
| static inline void atomic64_set(atomic64_t *v, long long i) |
| { |
| __asm__ __volatile__("@ atomic64_set\n" |
| " strd %2, %H2, [%1]" |
| : "=Qo" (v->counter) |
| : "r" (&v->counter), "r" (i) |
| ); |
| } |
| #else |
| static inline long long atomic64_read(const atomic64_t *v) |
| { |
| long long result; |
| |
| __asm__ __volatile__("@ atomic64_read\n" |
| " ldrexd %0, %H0, [%1]" |
| : "=&r" (result) |
| : "r" (&v->counter), "Qo" (v->counter) |
| ); |
| |
| return result; |
| } |
| |
| static inline void atomic64_set(atomic64_t *v, long long i) |
| { |
| long long tmp; |
| |
| prefetchw(&v->counter); |
| __asm__ __volatile__("@ atomic64_set\n" |
| "1: ldrexd %0, %H0, [%2]\n" |
| " strexd %0, %3, %H3, [%2]\n" |
| " teq %0, #0\n" |
| " bne 1b" |
| : "=&r" (tmp), "=Qo" (v->counter) |
| : "r" (&v->counter), "r" (i) |
| : "cc"); |
| } |
| #endif |
| |
| #define ATOMIC64_OP(op, op1, op2) \ |
| static inline void atomic64_##op(long long i, atomic64_t *v) \ |
| { \ |
| long long result; \ |
| unsigned long tmp; \ |
| \ |
| prefetchw(&v->counter); \ |
| __asm__ __volatile__("@ atomic64_" #op "\n" \ |
| "1: ldrexd %0, %H0, [%3]\n" \ |
| " " #op1 " %Q0, %Q0, %Q4\n" \ |
| " " #op2 " %R0, %R0, %R4\n" \ |
| " strexd %1, %0, %H0, [%3]\n" \ |
| " teq %1, #0\n" \ |
| " bne 1b" \ |
| : "=&r" (result), "=&r" (tmp), "+Qo" (v->counter) \ |
| : "r" (&v->counter), "r" (i) \ |
| : "cc"); \ |
| } \ |
| |
| #define ATOMIC64_OP_RETURN(op, op1, op2) \ |
| static inline long long \ |
| atomic64_##op##_return_relaxed(long long i, atomic64_t *v) \ |
| { \ |
| long long result; \ |
| unsigned long tmp; \ |
| \ |
| prefetchw(&v->counter); \ |
| \ |
| __asm__ __volatile__("@ atomic64_" #op "_return\n" \ |
| "1: ldrexd %0, %H0, [%3]\n" \ |
| " " #op1 " %Q0, %Q0, %Q4\n" \ |
| " " #op2 " %R0, %R0, %R4\n" \ |
| " strexd %1, %0, %H0, [%3]\n" \ |
| " teq %1, #0\n" \ |
| " bne 1b" \ |
| : "=&r" (result), "=&r" (tmp), "+Qo" (v->counter) \ |
| : "r" (&v->counter), "r" (i) \ |
| : "cc"); \ |
| \ |
| return result; \ |
| } |
| |
| #define ATOMIC64_OPS(op, op1, op2) \ |
| ATOMIC64_OP(op, op1, op2) \ |
| ATOMIC64_OP_RETURN(op, op1, op2) |
| |
| ATOMIC64_OPS(add, adds, adc) |
| ATOMIC64_OPS(sub, subs, sbc) |
| |
| #define atomic64_add_return_relaxed atomic64_add_return_relaxed |
| #define atomic64_sub_return_relaxed atomic64_sub_return_relaxed |
| |
| #define atomic64_andnot atomic64_andnot |
| |
| ATOMIC64_OP(and, and, and) |
| ATOMIC64_OP(andnot, bic, bic) |
| ATOMIC64_OP(or, orr, orr) |
| ATOMIC64_OP(xor, eor, eor) |
| |
| #undef ATOMIC64_OPS |
| #undef ATOMIC64_OP_RETURN |
| #undef ATOMIC64_OP |
| |
| static inline long long |
| atomic64_cmpxchg_relaxed(atomic64_t *ptr, long long old, long long new) |
| { |
| long long oldval; |
| unsigned long res; |
| |
| prefetchw(&ptr->counter); |
| |
| do { |
| __asm__ __volatile__("@ atomic64_cmpxchg\n" |
| "ldrexd %1, %H1, [%3]\n" |
| "mov %0, #0\n" |
| "teq %1, %4\n" |
| "teqeq %H1, %H4\n" |
| "strexdeq %0, %5, %H5, [%3]" |
| : "=&r" (res), "=&r" (oldval), "+Qo" (ptr->counter) |
| : "r" (&ptr->counter), "r" (old), "r" (new) |
| : "cc"); |
| } while (res); |
| |
| return oldval; |
| } |
| #define atomic64_cmpxchg_relaxed atomic64_cmpxchg_relaxed |
| |
| static inline long long atomic64_xchg_relaxed(atomic64_t *ptr, long long new) |
| { |
| long long result; |
| unsigned long tmp; |
| |
| prefetchw(&ptr->counter); |
| |
| __asm__ __volatile__("@ atomic64_xchg\n" |
| "1: ldrexd %0, %H0, [%3]\n" |
| " strexd %1, %4, %H4, [%3]\n" |
| " teq %1, #0\n" |
| " bne 1b" |
| : "=&r" (result), "=&r" (tmp), "+Qo" (ptr->counter) |
| : "r" (&ptr->counter), "r" (new) |
| : "cc"); |
| |
| return result; |
| } |
| #define atomic64_xchg_relaxed atomic64_xchg_relaxed |
| |
| static inline long long atomic64_dec_if_positive(atomic64_t *v) |
| { |
| long long result; |
| unsigned long tmp; |
| |
| smp_mb(); |
| prefetchw(&v->counter); |
| |
| __asm__ __volatile__("@ atomic64_dec_if_positive\n" |
| "1: ldrexd %0, %H0, [%3]\n" |
| " subs %Q0, %Q0, #1\n" |
| " sbc %R0, %R0, #0\n" |
| " teq %R0, #0\n" |
| " bmi 2f\n" |
| " strexd %1, %0, %H0, [%3]\n" |
| " teq %1, #0\n" |
| " bne 1b\n" |
| "2:" |
| : "=&r" (result), "=&r" (tmp), "+Qo" (v->counter) |
| : "r" (&v->counter) |
| : "cc"); |
| |
| smp_mb(); |
| |
| return result; |
| } |
| |
| static inline int atomic64_add_unless(atomic64_t *v, long long a, long long u) |
| { |
| long long val; |
| unsigned long tmp; |
| int ret = 1; |
| |
| smp_mb(); |
| prefetchw(&v->counter); |
| |
| __asm__ __volatile__("@ atomic64_add_unless\n" |
| "1: ldrexd %0, %H0, [%4]\n" |
| " teq %0, %5\n" |
| " teqeq %H0, %H5\n" |
| " moveq %1, #0\n" |
| " beq 2f\n" |
| " adds %Q0, %Q0, %Q6\n" |
| " adc %R0, %R0, %R6\n" |
| " strexd %2, %0, %H0, [%4]\n" |
| " teq %2, #0\n" |
| " bne 1b\n" |
| "2:" |
| : "=&r" (val), "+r" (ret), "=&r" (tmp), "+Qo" (v->counter) |
| : "r" (&v->counter), "r" (u), "r" (a) |
| : "cc"); |
| |
| if (ret) |
| smp_mb(); |
| |
| return ret; |
| } |
| |
| #define atomic64_add_negative(a, v) (atomic64_add_return((a), (v)) < 0) |
| #define atomic64_inc(v) atomic64_add(1LL, (v)) |
| #define atomic64_inc_return_relaxed(v) atomic64_add_return_relaxed(1LL, (v)) |
| #define atomic64_inc_and_test(v) (atomic64_inc_return(v) == 0) |
| #define atomic64_sub_and_test(a, v) (atomic64_sub_return((a), (v)) == 0) |
| #define atomic64_dec(v) atomic64_sub(1LL, (v)) |
| #define atomic64_dec_return_relaxed(v) atomic64_sub_return_relaxed(1LL, (v)) |
| #define atomic64_dec_and_test(v) (atomic64_dec_return((v)) == 0) |
| #define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1LL, 0LL) |
| |
| #endif /* !CONFIG_GENERIC_ATOMIC64 */ |
| #endif |
| #endif |