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 */ 50