arch/sh/include/asm/cmpxchg-irq.h

Source file repositories/reference/linux-study-clean/arch/sh/include/asm/cmpxchg-irq.h

File Facts

System
Linux kernel
Corpus path
arch/sh/include/asm/cmpxchg-irq.h
Extension
.h
Size
1065 bytes
Lines
55
Domain
Architecture Layer
Bucket
arch/sh
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 __ASM_SH_CMPXCHG_IRQ_H
#define __ASM_SH_CMPXCHG_IRQ_H

#include <linux/irqflags.h>

static inline unsigned long xchg_u32(volatile u32 *m, unsigned long val)
{
	unsigned long flags, retval;

	local_irq_save(flags);
	retval = *m;
	*m = val;
	local_irq_restore(flags);
	return retval;
}

static inline unsigned long xchg_u16(volatile u16 *m, unsigned long val)
{
	unsigned long flags, retval;

	local_irq_save(flags);
	retval = *m;
	*m = val;
	local_irq_restore(flags);
	return retval;
}

static inline unsigned long xchg_u8(volatile u8 *m, unsigned long val)
{
	unsigned long flags, retval;

	local_irq_save(flags);
	retval = *m;
	*m = val & 0xff;
	local_irq_restore(flags);
	return retval;
}

static inline unsigned long __cmpxchg_u32(volatile int *m, unsigned long old,
	unsigned long new)
{
	__u32 retval;
	unsigned long flags;

	local_irq_save(flags);
	retval = *m;
	if (retval == old)
		*m = new;
	local_irq_restore(flags);       /* implies memory barrier  */
	return retval;
}

#endif /* __ASM_SH_CMPXCHG_IRQ_H */

Annotation

Implementation Notes