1 /* SPDX-License-Identifier: GPL-2.0 */ 2 /* 3 * Copyright (C) 2020-2021 Loongson Technology Corporation Limited 4 */ 5 #ifndef _ASM_SWITCH_TO_H 6 #define _ASM_SWITCH_TO_H 7 8 #include <asm/cpu-features.h> 9 #include <asm/fpu.h> 10 #include <asm/watch.h> 11 #include <asm/lbt.h> 12 13 struct task_struct; 14 15 /** 16 * __switch_to - switch execution of a task 17 * @prev: The task previously executed. 18 * @next: The task to begin executing. 19 * @next_ti: task_thread_info(next). 20 * @sched_ra: __schedule return address. 21 * @sched_cfa: __schedule call frame address. 22 * 23 * This function is used whilst scheduling to save the context of prev & load 24 * the context of next. Returns prev. 25 */ 26 extern asmlinkage struct task_struct *__switch_to(struct task_struct *prev, 27 struct task_struct *next, struct thread_info *next_ti, 28 void *sched_ra, void *sched_cfa); 29 30 /* 31 * For newly created kernel threads switch_to() will return to 32 * ret_from_kernel_thread, newly created user threads to ret_from_fork. 33 * That is, everything following __switch_to() will be skipped for new threads. 34 * So everything that matters to new threads should be placed before __switch_to(). 35 */ 36 #define switch_to(prev, next, last) \ 37 do { \ 38 lose_fpu_inatomic(1, prev); \ 39 lose_lbt_inatomic(1, prev); \ 40 __process_watch(prev, next); \ 41 (last) = __switch_to(prev, next, task_thread_info(next), \ 42 __builtin_return_address(0), __builtin_frame_address(0)); \ 43 } while (0) 44 45 #endif /* _ASM_SWITCH_TO_H */ 46