arch/m68k/include/asm/atomic.h

Source file repositories/reference/linux-study-clean/arch/m68k/include/asm/atomic.h

File Facts

System
Linux kernel
Corpus path
arch/m68k/include/asm/atomic.h
Extension
.h
Size
5306 bytes
Lines
222
Domain
Architecture Layer
Bucket
arch/m68k
Inferred role
Architecture Layer: implementation source
Status
source implementation candidate

Why This File Exists

CPU and platform-specific kernel glue: boot entry, traps, syscall entry, interrupts, page tables, context switch, and low-level barriers.

Dependency Surface

Detected Declarations

Annotated Snippet

#ifndef __ARCH_M68K_ATOMIC__
#define __ARCH_M68K_ATOMIC__

#include <linux/types.h>
#include <linux/irqflags.h>
#include <asm/cmpxchg.h>
#include <asm/barrier.h>

/*
 * Atomic operations that C can't guarantee us.  Useful for
 * resource counting etc..
 */

/*
 * We do not have SMP m68k systems, so we don't have to deal with that.
 */

#define arch_atomic_read(v)	READ_ONCE((v)->counter)
#define arch_atomic_set(v, i)	WRITE_ONCE(((v)->counter), (i))

/*
 * The ColdFire parts cannot do some immediate to memory operations,
 * so for them we do not specify the "i" asm constraint.
 */
#ifdef CONFIG_COLDFIRE
#define	ASM_DI	"d"
#else
#define	ASM_DI	"di"
#endif

#define ATOMIC_OP(op, c_op, asm_op)					\
static inline void arch_atomic_##op(int i, atomic_t *v)			\
{									\
	__asm__ __volatile__(#asm_op "l %1,%0" : "+m" (*v) : ASM_DI (i));\
}									\

#ifdef CONFIG_RMW_INSNS

#define ATOMIC_OP_RETURN(op, c_op, asm_op)				\
static inline int arch_atomic_##op##_return(int i, atomic_t *v)		\
{									\
	int t, tmp;							\
									\
	__asm__ __volatile__(						\
			"1:	movel %2,%1\n"				\
			"	" #asm_op "l %3,%1\n"			\
			"	casl %2,%1,%0\n"			\
			"	jne 1b"					\
			: "+m" (*v), "=&d" (t), "=&d" (tmp)		\
			: "di" (i), "2" (arch_atomic_read(v)));		\
	return t;							\
}

#define ATOMIC_FETCH_OP(op, c_op, asm_op)				\
static inline int arch_atomic_fetch_##op(int i, atomic_t *v)		\
{									\
	int t, tmp;							\
									\
	__asm__ __volatile__(						\
			"1:	movel %2,%1\n"				\
			"	" #asm_op "l %3,%1\n"			\
			"	casl %2,%1,%0\n"			\
			"	jne 1b"					\
			: "+m" (*v), "=&d" (t), "=&d" (tmp)		\
			: "di" (i), "2" (arch_atomic_read(v)));		\
	return tmp;							\
}

#else

#define ATOMIC_OP_RETURN(op, c_op, asm_op)				\
static inline int arch_atomic_##op##_return(int i, atomic_t * v)	\
{									\
	unsigned long flags;						\
	int t;								\
									\
	local_irq_save(flags);						\
	t = (v->counter c_op i);					\
	local_irq_restore(flags);					\
									\
	return t;							\
}

#define ATOMIC_FETCH_OP(op, c_op, asm_op)				\
static inline int arch_atomic_fetch_##op(int i, atomic_t * v)		\
{									\
	unsigned long flags;						\
	int t;								\
									\
	local_irq_save(flags);						\

Annotation

Implementation Notes