xref: /OK3568_Linux_fs/kernel/arch/arm/mach-imx/hotplug.c (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0-or-later
2*4882a593Smuzhiyun /*
3*4882a593Smuzhiyun  * Copyright 2011 Freescale Semiconductor, Inc.
4*4882a593Smuzhiyun  * Copyright 2011 Linaro Ltd.
5*4882a593Smuzhiyun  */
6*4882a593Smuzhiyun 
7*4882a593Smuzhiyun #include <linux/errno.h>
8*4882a593Smuzhiyun #include <linux/jiffies.h>
9*4882a593Smuzhiyun #include <asm/cacheflush.h>
10*4882a593Smuzhiyun #include <asm/cp15.h>
11*4882a593Smuzhiyun #include <asm/proc-fns.h>
12*4882a593Smuzhiyun 
13*4882a593Smuzhiyun #include "common.h"
14*4882a593Smuzhiyun 
15*4882a593Smuzhiyun /*
16*4882a593Smuzhiyun  * platform-specific code to shutdown a CPU
17*4882a593Smuzhiyun  *
18*4882a593Smuzhiyun  * Called with IRQs disabled
19*4882a593Smuzhiyun  */
imx_cpu_die(unsigned int cpu)20*4882a593Smuzhiyun void imx_cpu_die(unsigned int cpu)
21*4882a593Smuzhiyun {
22*4882a593Smuzhiyun 	v7_exit_coherency_flush(louis);
23*4882a593Smuzhiyun 	/*
24*4882a593Smuzhiyun 	 * We use the cpu jumping argument register to sync with
25*4882a593Smuzhiyun 	 * imx_cpu_kill() which is running on cpu0 and waiting for
26*4882a593Smuzhiyun 	 * the register being cleared to kill the cpu.
27*4882a593Smuzhiyun 	 */
28*4882a593Smuzhiyun 	imx_set_cpu_arg(cpu, ~0);
29*4882a593Smuzhiyun 
30*4882a593Smuzhiyun 	while (1)
31*4882a593Smuzhiyun 		cpu_do_idle();
32*4882a593Smuzhiyun }
33*4882a593Smuzhiyun 
imx_cpu_kill(unsigned int cpu)34*4882a593Smuzhiyun int imx_cpu_kill(unsigned int cpu)
35*4882a593Smuzhiyun {
36*4882a593Smuzhiyun 	unsigned long timeout = jiffies + msecs_to_jiffies(50);
37*4882a593Smuzhiyun 
38*4882a593Smuzhiyun 	while (imx_get_cpu_arg(cpu) == 0)
39*4882a593Smuzhiyun 		if (time_after(jiffies, timeout))
40*4882a593Smuzhiyun 			return 0;
41*4882a593Smuzhiyun 	imx_enable_cpu(cpu, false);
42*4882a593Smuzhiyun 	imx_set_cpu_arg(cpu, 0);
43*4882a593Smuzhiyun 	return 1;
44*4882a593Smuzhiyun }
45