xref: /openbmc/linux/arch/s390/include/asm/switch_to.h (revision 171fa692)
1 /*
2  * Copyright IBM Corp. 1999, 2009
3  *
4  * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
5  */
6 
7 #ifndef __ASM_SWITCH_TO_H
8 #define __ASM_SWITCH_TO_H
9 
10 #include <linux/thread_info.h>
11 #include <asm/fpu/api.h>
12 #include <asm/ptrace.h>
13 #include <asm/guarded_storage.h>
14 
15 extern struct task_struct *__switch_to(void *, void *);
16 extern void update_cr_regs(struct task_struct *task);
17 
18 static inline void save_access_regs(unsigned int *acrs)
19 {
20 	typedef struct { int _[NUM_ACRS]; } acrstype;
21 
22 	asm volatile("stam 0,15,%0" : "=Q" (*(acrstype *)acrs));
23 }
24 
25 static inline void restore_access_regs(unsigned int *acrs)
26 {
27 	typedef struct { int _[NUM_ACRS]; } acrstype;
28 
29 	asm volatile("lam 0,15,%0" : : "Q" (*(acrstype *)acrs));
30 }
31 
32 #define switch_to(prev,next,last) do {					\
33 	if (prev->mm) {							\
34 		save_fpu_regs();					\
35 		save_access_regs(&prev->thread.acrs[0]);		\
36 		save_ri_cb(prev->thread.ri_cb);				\
37 		save_gs_cb(prev->thread.gs_cb);				\
38 	}								\
39 	if (next->mm) {							\
40 		update_cr_regs(next);					\
41 		set_cpu_flag(CIF_FPU);					\
42 		restore_access_regs(&next->thread.acrs[0]);		\
43 		restore_ri_cb(next->thread.ri_cb, prev->thread.ri_cb);	\
44 		restore_gs_cb(next->thread.gs_cb);			\
45 	}								\
46 	prev = __switch_to(prev,next);					\
47 } while (0)
48 
49 #endif /* __ASM_SWITCH_TO_H */
50