linux_dsm_epyc7002/arch/arm/mach-imx/hotplug.c
Thomas Gleixner fcaf20360a treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 159
Based on 1 normalized pattern(s):

  the code contained herein is licensed under the gnu general public
  license you may obtain a copy of the gnu general public license
  version 2 or later at the following locations http www opensource
  org licenses gpl license html http www gnu org copyleft gpl html

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 161 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070033.383790741@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:26:37 -07:00

65 lines
1.3 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Copyright 2011 Freescale Semiconductor, Inc.
* Copyright 2011 Linaro Ltd.
*/
#include <linux/errno.h>
#include <linux/jiffies.h>
#include <asm/cp15.h>
#include <asm/proc-fns.h>
#include "common.h"
static inline void cpu_enter_lowpower(void)
{
unsigned int v;
asm volatile(
"mcr p15, 0, %1, c7, c5, 0\n"
" mcr p15, 0, %1, c7, c10, 4\n"
/*
* Turn off coherency
*/
" mrc p15, 0, %0, c1, c0, 1\n"
" bic %0, %0, %3\n"
" mcr p15, 0, %0, c1, c0, 1\n"
" mrc p15, 0, %0, c1, c0, 0\n"
" bic %0, %0, %2\n"
" mcr p15, 0, %0, c1, c0, 0\n"
: "=&r" (v)
: "r" (0), "Ir" (CR_C), "Ir" (0x40)
: "cc");
}
/*
* platform-specific code to shutdown a CPU
*
* Called with IRQs disabled
*/
void imx_cpu_die(unsigned int cpu)
{
cpu_enter_lowpower();
/*
* We use the cpu jumping argument register to sync with
* imx_cpu_kill() which is running on cpu0 and waiting for
* the register being cleared to kill the cpu.
*/
imx_set_cpu_arg(cpu, ~0);
while (1)
cpu_do_idle();
}
int imx_cpu_kill(unsigned int cpu)
{
unsigned long timeout = jiffies + msecs_to_jiffies(50);
while (imx_get_cpu_arg(cpu) == 0)
if (time_after(jiffies, timeout))
return 0;
imx_enable_cpu(cpu, false);
imx_set_cpu_arg(cpu, 0);
return 1;
}