1/*
 2 * SMP support for R-Mobile / SH-Mobile
 3 *
 4 * Copyright (C) 2010  Magnus Damm
 5 *
 6 * Based on realview, Copyright (C) 2002 ARM Ltd, All Rights Reserved
 7 *
 8 * This program is free software; you can redistribute it and/or modify
 9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
11 */
12#include <linux/kernel.h>
13#include <linux/errno.h>
14#include <linux/smp.h>
15#include <linux/cpumask.h>
16#include <linux/delay.h>
17#include <mach/common.h>
18#include <asm/cacheflush.h>
19
20static cpumask_t dead_cpus;
21
22int platform_cpu_kill(unsigned int cpu)
23{
24	int k;
25
26	/* this function is running on another CPU than the offline target,
27	 * here we need wait for shutdown code in platform_cpu_die() to
28	 * finish before asking SoC-specific code to power off the CPU core.
29	 */
30	for (k = 0; k < 1000; k++) {
31		if (cpumask_test_cpu(cpu, &dead_cpus))
32			return shmobile_platform_cpu_kill(cpu);
33
34		mdelay(1);
35	}
36
37	return 0;
38}
39
40void platform_cpu_die(unsigned int cpu)
41{
42	/* hardware shutdown code running on the CPU that is being offlined */
43	flush_cache_all();
44	dsb();
45
46	/* notify platform_cpu_kill() that hardware shutdown is finished */
47	cpumask_set_cpu(cpu, &dead_cpus);
48
49	/* wait for SoC code in platform_cpu_kill() to shut off CPU core
50	 * power. CPU bring up starts from the reset vector.
51	 */
52	while (1) {
53		/*
54		 * here's the WFI
55		 */
56		asm(".word	0xe320f003\n"
57		    :
58		    :
59		    : "memory", "cc");
60	}
61}
62
63int platform_cpu_disable(unsigned int cpu)
64{
65	cpumask_clear_cpu(cpu, &dead_cpus);
66	/*
67	 * we don't allow CPU 0 to be shutdown (it is still too special
68	 * e.g. clock tick interrupts)
69	 */
70	return cpu == 0 ? -EPERM : 0;
71}

 1/*
 2 * SMP support for R-Mobile / SH-Mobile
 3 *
 4 * Copyright (C) 2010  Magnus Damm
 5 *
 6 * Based on realview, Copyright (C) 2002 ARM Ltd, All Rights Reserved
 7 *
 8 * This program is free software; you can redistribute it and/or modify
 9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
11 */
12#include <linux/kernel.h>
13#include <linux/errno.h>
14#include <linux/smp.h>
 
 
 
 
 
 
15
16int platform_cpu_kill(unsigned int cpu)
17{
18	return 1;
 
 
 
 
 
 
 
 
 
 
 
 
 
19}
20
21void platform_cpu_die(unsigned int cpu)
22{
 
 
 
 
 
 
 
 
 
 
23	while (1) {
24		/*
25		 * here's the WFI
26		 */
27		asm(".word	0xe320f003\n"
28		    :
29		    :
30		    : "memory", "cc");
31	}
32}
33
34int platform_cpu_disable(unsigned int cpu)
35{
 
36	/*
37	 * we don't allow CPU 0 to be shutdown (it is still too special
38	 * e.g. clock tick interrupts)
39	 */
40	return cpu == 0 ? -EPERM : 0;
41}