xref: /linux/arch/arm/mach-imx/hotplug.c (revision ca853314e78b0a65c20b6a889a23c31f918d4aa2)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Copyright 2011 Freescale Semiconductor, Inc.
4  * Copyright 2011 Linaro Ltd.
5  */
6 
7 #include <linux/errno.h>
8 #include <linux/jiffies.h>
9 #include <asm/cacheflush.h>
10 #include <asm/cp15.h>
11 #include <asm/proc-fns.h>
12 
13 #include "common.h"
14 
15 /*
16  * platform-specific code to shutdown a CPU
17  *
18  * Called with IRQs disabled
19  */
20 void imx_cpu_die(unsigned int cpu)
21 {
22 	v7_exit_coherency_flush(louis);
23 	/*
24 	 * We use the cpu jumping argument register to sync with
25 	 * imx_cpu_kill() which is running on cpu0 and waiting for
26 	 * the register being cleared to kill the cpu.
27 	 */
28 	imx_set_cpu_arg(cpu, ~0);
29 
30 	while (1)
31 		cpu_do_idle();
32 }
33 
34 int imx_cpu_kill(unsigned int cpu)
35 {
36 	unsigned long timeout = jiffies + msecs_to_jiffies(50);
37 
38 	while (imx_get_cpu_arg(cpu) == 0)
39 		if (time_after(jiffies, timeout))
40 			return 0;
41 	imx_enable_cpu(cpu, false);
42 	imx_set_cpu_arg(cpu, 0);
43 	return 1;
44 }
45