xref: /linux/arch/loongarch/kernel/switch.S (revision b61104e7a6349bd2c2b3e2fb3260d87f15eda8f4)
1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
4 */
5#include <asm/asm.h>
6#include <asm/asmmacro.h>
7#include <asm/asm-offsets.h>
8#include <asm/loongarch.h>
9#include <asm/regdef.h>
10#include <asm/stackframe.h>
11#include <asm/thread_info.h>
12
13/*
14 * task_struct *__switch_to(task_struct *prev, task_struct *next,
15 *			    struct thread_info *next_ti, void *sched_ra, void *sched_cfa)
16 */
17	.align	5
18SYM_FUNC_START(__switch_to)
19#ifdef CONFIG_32BIT
20	PTR_ADDI	a0, a0, TASK_STRUCT_OFFSET
21	PTR_ADDI	a1, a1, TASK_STRUCT_OFFSET
22#endif
23	csrrd		t1, LOONGARCH_CSR_PRMD
24	LONG_SPTR	t1, a0, (THREAD_CSRPRMD - TASK_STRUCT_OFFSET)
25
26	cpu_save_nonscratch a0
27	LONG_SPTR	a3, a0, (THREAD_SCHED_RA - TASK_STRUCT_OFFSET)
28	LONG_SPTR	a4, a0, (THREAD_SCHED_CFA - TASK_STRUCT_OFFSET)
29
30#if defined(CONFIG_STACKPROTECTOR) && !defined(CONFIG_SMP)
31	la		t7, __stack_chk_guard
32	LONG_LPTR	t8, a1, (TASK_STACK_CANARY - TASK_STRUCT_OFFSET)
33	LONG_SPTR	t8, t7, 0
34#endif
35
36	move	tp, a2
37	cpu_restore_nonscratch a1
38
39	li.w		t0, _THREAD_SIZE
40	PTR_ADD		t0, t0, tp
41	set_saved_sp	t0, t1, t2
42
43	LONG_LPTR	t1, a1, (THREAD_CSRPRMD - TASK_STRUCT_OFFSET)
44	csrwr		t1, LOONGARCH_CSR_PRMD
45
46#ifdef CONFIG_32BIT
47	PTR_ADDI	a0, a0, -TASK_STRUCT_OFFSET
48#endif
49	jr	ra
50SYM_FUNC_END(__switch_to)
51