1/* SPDX-License-Identifier: GPL-2.0 */
 2/*
 3 * Copyright IBM Corp. 1999, 2009
 4 *
 5 * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
 6 */
 7
 8#ifndef __ASM_SWITCH_TO_H
 9#define __ASM_SWITCH_TO_H
10
11#include <linux/thread_info.h>
12#include <asm/fpu/api.h>
13#include <asm/ptrace.h>
14#include <asm/guarded_storage.h>
15
16extern struct task_struct *__switch_to(void *, void *);
17extern void update_cr_regs(struct task_struct *task);
18
19static inline void save_access_regs(unsigned int *acrs)
20{
21	typedef struct { int _[NUM_ACRS]; } acrstype;
22
23	asm volatile("stam 0,15,%0" : "=Q" (*(acrstype *)acrs));
24}
25
26static inline void restore_access_regs(unsigned int *acrs)
27{
28	typedef struct { int _[NUM_ACRS]; } acrstype;
29
30	asm volatile("lam 0,15,%0" : : "Q" (*(acrstype *)acrs));
31}
32
33#define switch_to(prev, next, last) do {				\
34	/* save_fpu_regs() sets the CIF_FPU flag, which enforces	\
35	 * a restore of the floating point / vector registers as	\
36	 * soon as the next task returns to user space			\
37	 */								\
38	save_fpu_regs();						\
39	save_access_regs(&prev->thread.acrs[0]);			\
40	save_ri_cb(prev->thread.ri_cb);					\
41	save_gs_cb(prev->thread.gs_cb);					\
42	update_cr_regs(next);						\
43	restore_access_regs(&next->thread.acrs[0]);			\
44	restore_ri_cb(next->thread.ri_cb, prev->thread.ri_cb);		\
45	restore_gs_cb(next->thread.gs_cb);				\
46	prev = __switch_to(prev, next);					\
47} while (0)
48
49#endif /* __ASM_SWITCH_TO_H */