kernel_optimize_test/arch/arc/kernel/ctx_sw_asm.S
Thomas Gleixner d2912cb15b treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500
Based on 2 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license version 2 as
  published by the free software foundation

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license version 2 as
  published by the free software foundation #

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 4122 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Enrico Weigelt <info@metux.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-19 17:09:55 +02:00

61 lines
1.5 KiB
ArmAsm

/* 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>
#define KSP_WORD_OFF ((TASK_THREAD + THREAD_KSP) / 4)
;################### Low Level Context Switch ##########################
.section .sched.text,"ax",@progbits
.align 4
.global __switch_to
.type __switch_to, @function
__switch_to:
CFI_STARTPROC
/* Save regs on kernel mode stack of task */
st.a blink, [sp, -4]
st.a fp, [sp, -4]
SAVE_CALLEE_SAVED_KERNEL
/* Save the now KSP in task->thread.ksp */
#if KSP_WORD_OFF <= 255
st.as sp, [r0, KSP_WORD_OFF]
#else
/* Workaround for NR_CPUS=4k as ST.as can only take s9 offset */
add2 r24, r0, KSP_WORD_OFF
st sp, [r24]
#endif
/*
* Return last task in r0 (return reg)
* On ARC, Return reg = First Arg reg = r0.
* Since we already have last task in r0,
* don't need to do anything special to return it
*/
/*
* switch to new task, contained in r1
* Temp reg r3 is required to get the ptr to store val
*/
SET_CURR_TASK_ON_CPU r1, r3
/* reload SP with kernel mode stack pointer in task->thread.ksp */
ld.as sp, [r1, (TASK_THREAD + THREAD_KSP)/4]
/* restore the registers */
RESTORE_CALLEE_SAVED_KERNEL
ld.ab fp, [sp, 4]
ld.ab blink, [sp, 4]
j [blink]
END_CFI(__switch_to)