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
|
/*
* SMP support for SoCs with SCU covered by mach-shmobile
*
* Copyright (C) 2013 Magnus Damm
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/cpu.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/smp.h>
#include <asm/cacheflush.h>
#include <asm/smp_plat.h>
#include <asm/smp_scu.h>
#include "common.h"
static phys_addr_t shmobile_scu_base_phys;
static void __iomem *shmobile_scu_base;
static int shmobile_scu_cpu_prepare(unsigned int cpu)
{
/* For this particular CPU register SCU SMP boot vector */
shmobile_smp_hook(cpu, __pa_symbol(shmobile_boot_scu),
shmobile_scu_base_phys);
return 0;
}
void __init shmobile_smp_scu_prepare_cpus(phys_addr_t scu_base_phys,
unsigned int max_cpus)
{
/* install boot code shared by all CPUs */
shmobile_boot_fn = __pa_symbol(shmobile_smp_boot);
/* enable SCU and cache coherency on booting CPU */
shmobile_scu_base_phys = scu_base_phys;
shmobile_scu_base = ioremap(scu_base_phys, PAGE_SIZE);
scu_enable(shmobile_scu_base);
scu_power_mode(shmobile_scu_base, SCU_PM_NORMAL);
/* Use CPU notifier for reset vector control */
cpuhp_setup_state_nocalls(CPUHP_ARM_SHMOBILE_SCU_PREPARE,
"arm/shmobile-scu:prepare",
shmobile_scu_cpu_prepare, NULL);
}
#ifdef CONFIG_HOTPLUG_CPU
void shmobile_smp_scu_cpu_die(unsigned int cpu)
{
/* For this particular CPU deregister boot vector */
shmobile_smp_hook(cpu, 0, 0);
dsb();
flush_cache_all();
/* disable cache coherency */
scu_power_mode(shmobile_scu_base, SCU_PM_POWEROFF);
/* jump to shared mach-shmobile sleep / reset code */
shmobile_smp_sleep();
}
static int shmobile_smp_scu_psr_core_disabled(int cpu)
{
unsigned long mask = SCU_PM_POWEROFF << (cpu * 8);
if ((__raw_readl(shmobile_scu_base + 8) & mask) == mask)
return 1;
return 0;
}
int shmobile_smp_scu_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_smp_scu_psr_core_disabled(cpu))
return 1;
mdelay(1);
}
return 0;
}
#endif
|
