| 123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307308309310311312313314315316317318319320321322323324325326327328329330331332333334335336337338339340341342343344345346347348349350351352353354355356357358359360361362 | /* *  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/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)	(*(volatile int *)&(v)->counter)#define atomic_set(v,i)	(((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. */static inline void atomic_add(int i, atomic_t *v){	unsigned long tmp;	int result;	__asm__ __volatile__("@ atomic_add\n""1:	ldrex	%0, [%3]\n""	add	%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");}static inline int atomic_add_return(int i, atomic_t *v){	unsigned long tmp;	int result;	smp_mb();	__asm__ __volatile__("@ atomic_add_return\n""1:	ldrex	%0, [%3]\n""	add	%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");	smp_mb();	return result;}static inline void atomic_sub(int i, atomic_t *v){	unsigned long tmp;	int result;	__asm__ __volatile__("@ atomic_sub\n""1:	ldrex	%0, [%3]\n""	sub	%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");}static inline int atomic_sub_return(int i, atomic_t *v){	unsigned long tmp;	int result;	smp_mb();	__asm__ __volatile__("@ atomic_sub_return\n""1:	ldrex	%0, [%3]\n""	sub	%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");	smp_mb();	return result;}static inline int atomic_cmpxchg(atomic_t *ptr, int old, int new){	unsigned long oldval, res;	smp_mb();	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);	smp_mb();	return oldval;}static inline void atomic_clear_mask(unsigned long mask, unsigned long *addr){	unsigned long tmp, tmp2;	__asm__ __volatile__("@ atomic_clear_mask\n""1:	ldrex	%0, [%3]\n""	bic	%0, %0, %4\n""	strex	%1, %0, [%3]\n""	teq	%1, #0\n""	bne	1b"	: "=&r" (tmp), "=&r" (tmp2), "+Qo" (*addr)	: "r" (addr), "Ir" (mask)	: "cc");}#else /* ARM_ARCH_6 */#ifdef CONFIG_SMP#error SMP not supported on pre-ARMv6 CPUs#endifstatic inline int atomic_add_return(int i, atomic_t *v){	unsigned long flags;	int val;	raw_local_irq_save(flags);	val = v->counter;	v->counter = val += i;	raw_local_irq_restore(flags);	return val;}#define atomic_add(i, v)	(void) atomic_add_return(i, v)static inline int atomic_sub_return(int i, atomic_t *v){	unsigned long flags;	int val;	raw_local_irq_save(flags);	val = v->counter;	v->counter = val -= i;	raw_local_irq_restore(flags);	return val;}#define atomic_sub(i, v)	(void) atomic_sub_return(i, v)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 void atomic_clear_mask(unsigned long mask, unsigned long *addr){	unsigned long flags;	raw_local_irq_save(flags);	*addr &= ~mask;	raw_local_irq_restore(flags);}#endif /* __LINUX_ARM_ARCH__ */#define atomic_xchg(v, new) (xchg(&((v)->counter), new))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;}#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(v)    (atomic_add_return(1, v))#define atomic_dec_return(v)    (atomic_sub_return(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)#define smp_mb__before_atomic_dec()	smp_mb()#define smp_mb__after_atomic_dec()	smp_mb()#define smp_mb__before_atomic_inc()	smp_mb()#define smp_mb__after_atomic_inc()	smp_mb()#ifndef CONFIG_GENERIC_ATOMIC64typedef struct {	u64 __aligned(8) counter;} atomic64_t;#define ATOMIC64_INIT(i) { (i) }static inline u64 atomic64_read(const atomic64_t *v){	u64 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, u64 i){	u64 tmp;	__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");}static inline void atomic64_add(u64 i, atomic64_t *v){	u64 result;	unsigned long tmp;	__asm__ __volatile__("@ atomic64_add\n""1:	ldrexd	%0, %H0, [%3]\n""	adds	%0, %0, %4\n""	adc	%H0, %H0, %H4\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");}static inline u64 atomic64_add_return(u64 i, atomic64_t *v){	u64 result;	unsigned long tmp;	smp_mb();	__asm__ __volatile__("@ atomic64_add_return\n""1:	ldrexd	%0, %H0, [%3]\n""	adds	%0, %0, %4\n""	adc	%H0, %H0, %H4\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");	smp_mb();	return result;}static inline void atomic64_sub(u64 i, atomic64_t *v){	u64 result;	unsigned long tmp;	__asm__ __volatile__("@ atomic64_sub\n""1:	ldrexd	%0, %H0, [%3]\n""	subs	%0, %0, %4\n""	sbc	%H0, %H0, %H4\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");}static inline u64 atomic64_sub_return(u64 i, atomic64_t *v){	u64 result;	unsigned long tmp;	smp_mb();	__asm__ __volatile__("@ atomic64_sub_return\n""1:	ldrexd	%0, %H0, [%3]\n""	subs	%0, %0, %4\n""	sbc	%H0, %H0, %H4\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");	smp_mb();	return result;}static inline u64 atomic64_cmpxchg(atomic64_t *ptr, u64 old, u64 new){	u64 oldval;	unsigned long res;	smp_mb();	do {		__asm__ __volatile__("@ atomic64_cmpxchg\n"		"ldrexd		%1, %H1, [%3]\n"
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