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

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

File Facts

System
Linux kernel
Corpus path
arch/sh/include/asm/cmpxchg-llsc.h
Extension
.h
Size
1085 bytes
Lines
54
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_LLSC_H
#define __ASM_SH_CMPXCHG_LLSC_H

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

	__asm__ __volatile__ (
		"1:					\n\t"
		"movli.l	@%2, %0	! xchg_u32	\n\t"
		"mov		%0, %1			\n\t"
		"mov		%3, %0			\n\t"
		"movco.l	%0, @%2			\n\t"
		"bf		1b			\n\t"
		"synco					\n\t"
		: "=&z"(tmp), "=&r" (retval)
		: "r" (m), "r" (val)
		: "t", "memory"
	);

	return retval;
}

static inline unsigned long
__cmpxchg_u32(volatile u32 *m, unsigned long old, unsigned long new)
{
	unsigned long retval;
	unsigned long tmp;

	__asm__ __volatile__ (
		"1:						\n\t"
		"movli.l	@%2, %0	! __cmpxchg_u32		\n\t"
		"mov		%0, %1				\n\t"
		"cmp/eq		%1, %3				\n\t"
		"bf		2f				\n\t"
		"mov		%4, %0				\n\t"
		"2:						\n\t"
		"movco.l	%0, @%2				\n\t"
		"bf		1b				\n\t"
		"synco						\n\t"
		: "=&z" (tmp), "=&r" (retval)
		: "r" (m), "r" (old), "r" (new)
		: "t", "memory"
	);

	return retval;
}

#include <asm/cmpxchg-xchg.h>

#endif /* __ASM_SH_CMPXCHG_LLSC_H */

Annotation

Implementation Notes