/* SPDX-License-Identifier: GPL-2.0-only */
/*
* Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
*
* Vineetg: Aug 2009
* -Moved core context switch macro out of entry.S into this file.
* -This is the more "natural" hand written assembler
*/
#include <linux/linkage.h>
#include <asm/entry.h>
/* For the SAVE_* macros */
#include <asm/asm-offsets.h>
; IN
; - r0: prev task (also current)
; - r1: next task
; OUT
; - r0: prev task (so r0 not touched)
.
section .sched.text,
"ax",@progbits
ENTRY_CFI(__switch_to)
/* save kernel stack frame regs of @prev task */
push blink
CFI_DEF_CFA_OFFSET 4
CFI_OFFSET r31, -4
push fp
CFI_DEF_CFA_OFFSET 8
CFI_OFFSET r27, -8
mov fp, sp
CFI_DEF_CFA_REGISTER r27
/* kernel mode callee regs of @prev */
SAVE_CALLEE_SAVED_KERNEL
/*
* save final SP to @prev->thread_info.ksp
* @prev is "current" so thread_info derived from SP
*/
GET_CURR_THR_INFO_FROM_SP r10
st sp, [r10, THREAD_INFO_KSP]
/* update @next in _current_task[] and GP register caching it */
SET_CURR_TASK_ON_CPU r1, r10
/* load SP from @next->thread_info.ksp */
ld r10, [r1, TASK_THREAD_INFO]
ld sp, [r10, THREAD_INFO_KSP]
/* restore callee regs, stack frame regs of @next */
RESTORE_CALLEE_SAVED_KERNEL
pop fp
CFI_RESTORE r27
CFI_DEF_CFA r28, 4
pop blink
CFI_RESTORE r31
CFI_DEF_CFA_OFFSET 0
j [blink]
END_CFI(__switch_to)
