summaryrefslogtreecommitdiffstats
path: root/arch/arm/mach-shmobile/smp-emev2.c
blob: f978c5d0e1ae98051159b6b6dce04db532f09a2d (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
/*
 * SMP support for Emma Mobile EV2
 *
 * Copyright (C) 2012  Renesas Solutions Corp.
 * Copyright (C) 2012  Magnus Damm
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; version 2 of the License.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/smp.h>
#include <linux/spinlock.h>
#include <linux/io.h>
#include <linux/delay.h>
#include <mach/common.h>
#include <mach/emev2.h>
#include <asm/smp_plat.h>
#include <asm/smp_scu.h>
#include <asm/hardware/gic.h>
#include <asm/cacheflush.h>

#define EMEV2_SCU_BASE 0x1e000000

static DEFINE_SPINLOCK(scu_lock);
static void __iomem *scu_base;

static void modify_scu_cpu_psr(unsigned long set, unsigned long clr)
{
	unsigned long tmp;

	/* we assume this code is running on a different cpu
	 * than the one that is changing coherency setting */
	spin_lock(&scu_lock);
	tmp = readl(scu_base + 8);
	tmp &= ~clr;
	tmp |= set;
	writel(tmp, scu_base + 8);
	spin_unlock(&scu_lock);

}

static unsigned int __init emev2_get_core_count(void)
{
	if (!scu_base) {
		scu_base = ioremap(EMEV2_SCU_BASE, PAGE_SIZE);
		emev2_clock_init(); /* need ioremapped SMU */
	}

	WARN_ON_ONCE(!scu_base);

	return scu_base ? scu_get_core_count(scu_base) : 1;
}

static int emev2_platform_cpu_kill(unsigned int cpu)
{
	return 0; /* not supported yet */
}

static int __maybe_unused emev2_cpu_kill(unsigned int cpu)
{
	int k;

	/* this function is running on another CPU than the offline target,
	 * here we need wait for shutdown code in platform_cpu_die() to
	 * finish before asking SoC-specific code to power off the CPU core.
	 */
	for (k = 0; k < 1000; k++) {
		if (shmobile_cpu_is_dead(cpu))
			return emev2_platform_cpu_kill(cpu);
		mdelay(1);
	}

	return 0;
}


static void __cpuinit emev2_secondary_init(unsigned int cpu)
{
	gic_secondary_init(0);
}

static int __cpuinit emev2_boot_secondary(unsigned int cpu, struct task_struct *idle)
{
	cpu = cpu_logical_map(cpu);

	/* enable cache coherency */
	modify_scu_cpu_psr(0, 3 << (cpu * 8));

	/* Tell ROM loader about our vector (in headsmp.S) */
	emev2_set_boot_vector(__pa(shmobile_secondary_vector));

	gic_raise_softirq(cpumask_of(cpu), 1);
	return 0;
}

static void __init emev2_smp_prepare_cpus(unsigned int max_cpus)
{
	int cpu = cpu_logical_map(0);

	scu_enable(scu_base);

	/* enable cache coherency on CPU0 */
	modify_scu_cpu_psr(0, 3 << (cpu * 8));
}

static void __init emev2_smp_init_cpus(void)
{
	unsigned int ncores = emev2_get_core_count();

	shmobile_smp_init_cpus(ncores);
}

struct smp_operations emev2_smp_ops __initdata = {
	.smp_init_cpus		= emev2_smp_init_cpus,
	.smp_prepare_cpus	= emev2_smp_prepare_cpus,
	.smp_secondary_init	= emev2_secondary_init,
	.smp_boot_secondary	= emev2_boot_secondary,
#ifdef CONFIG_HOTPLUG_CPU
	.cpu_kill		= emev2_cpu_kill,
	.cpu_die		= shmobile_cpu_die,
	.cpu_disable		= shmobile_cpu_disable,
#endif
};