linux/arch/loongarch/kernel/switch.S
Jinyang He b40fa75e15 LoongArch: Remove unused kernel stack padding
The current LoongArch kernel stack is padded as if obeying the MIPS o32
calling convention (32 bytes), signifying the port's MIPS lineage but no
longer making sense. Remove the padding for clarity.

Reviewed-by: WANG Xuerui <git@xen0n.name>
Signed-off-by: Jinyang He <hejinyang@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2022-10-29 16:29:31 +08:00

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839 B
ArmAsm

/* SPDX-License-Identifier: GPL-2.0 */
/*
* Copyright (C) 2020-2022 Loongson Technology Corporation Limited
*/
#include <asm/asm.h>
#include <asm/asmmacro.h>
#include <asm/asm-offsets.h>
#include <asm/loongarch.h>
#include <asm/regdef.h>
#include <asm/stackframe.h>
#include <asm/thread_info.h>
/*
* task_struct *__switch_to(task_struct *prev, task_struct *next,
* struct thread_info *next_ti)
*/
.align 5
SYM_FUNC_START(__switch_to)
csrrd t1, LOONGARCH_CSR_PRMD
stptr.d t1, a0, THREAD_CSRPRMD
cpu_save_nonscratch a0
stptr.d ra, a0, THREAD_REG01
stptr.d a3, a0, THREAD_SCHED_RA
stptr.d a4, a0, THREAD_SCHED_CFA
move tp, a2
cpu_restore_nonscratch a1
li.w t0, _THREAD_SIZE
PTR_ADD t0, t0, tp
set_saved_sp t0, t1, t2
ldptr.d t1, a1, THREAD_CSRPRMD
csrwr t1, LOONGARCH_CSR_PRMD
jr ra
SYM_FUNC_END(__switch_to)