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
16 extern struct task_struct *__switch_to(void *, void *);
17 extern void update_cr_regs(struct task_struct *task);
18
save_access_regs(unsigned int * acrs)19 static 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
restore_access_regs(unsigned int * acrs)26 static 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 */
50