1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3 * Copyright (C) 2020-2022 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/lbt.h>
11
12 struct task_struct;
13
14 /**
15 * __switch_to - switch execution of a task
16 * @prev: The task previously executed.
17 * @next: The task to begin executing.
18 * @next_ti: task_thread_info(next).
19 * @sched_ra: __schedule return address.
20 * @sched_cfa: __schedule call frame address.
21 *
22 * This function is used whilst scheduling to save the context of prev & load
23 * the context of next. Returns prev.
24 */
25 extern asmlinkage struct task_struct *__switch_to(struct task_struct *prev,
26 struct task_struct *next, struct thread_info *next_ti,
27 void *sched_ra, void *sched_cfa);
28
29 /*
30 * For newly created kernel threads switch_to() will return to
31 * ret_from_kernel_thread, newly created user threads to ret_from_fork.
32 * That is, everything following __switch_to() will be skipped for new threads.
33 * So everything that matters to new threads should be placed before __switch_to().
34 */
35 #define switch_to(prev, next, last) \
36 do { \
37 lose_fpu_inatomic(1, prev); \
38 lose_lbt_inatomic(1, prev); \
39 hw_breakpoint_thread_switch(next); \
40 (last) = __switch_to(prev, next, task_thread_info(next), \
41 __builtin_return_address(0), __builtin_frame_address(0)); \
42 } while (0)
43
44 #endif /* _ASM_SWITCH_TO_H */
45
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.