1. 根目录:
2. arch
3. cris
4. include
5. asm
6. switch_to.h

#ifndef __ASM_CRIS_SWITCH_TO_H
#define __ASM_CRIS_SWITCH_TO_H

/* the switch_to macro calls resume, an asm function in entry.S which does the actual
 * task switching.
 */

extern struct task_struct *resume(struct task_struct *prev, struct task_struct *next, int);
#define switch_to(prev,next,last) last = resume(prev,next, \
					 (int)&((struct task_struct *)0)->thread)

#endif /* __ASM_CRIS_SWITCH_TO_H */