arch/nios2/include/asm/switch_to.h

Source file repositories/reference/linux-study-clean/arch/nios2/include/asm/switch_to.h

File Facts

System
Linux kernel
Corpus path
arch/nios2/include/asm/switch_to.h
Extension
.h
Size
866 bytes
Lines
32
Domain
Architecture Layer
Bucket
arch/nios2
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_NIOS2_SWITCH_TO_H
#define _ASM_NIOS2_SWITCH_TO_H

/*
 * switch_to(n) should switch tasks to task ptr, first checking that
 * ptr isn't the current task, in which case it does nothing.  This
 * also clears the TS-flag if the task we switched to has used the
 * math co-processor latest.
 */
#define switch_to(prev, next, last)			\
{							\
	void *_last;					\
	__asm__ __volatile__ (				\
		"mov	r4, %1\n"			\
		"mov	r5, %2\n"			\
		"call	resume\n"			\
		"mov	%0,r4\n"			\
		: "=r" (_last)				\
		: "r" (prev), "r" (next)		\
		: "r4", "r5", "r7", "r8", "ra");	\
	(last) = _last;					\
}

#endif /* _ASM_NIOS2_SWITCH_TO_H */

Annotation

Implementation Notes