platsmp.c
4.07 KB
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
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
/*
* Copyright (C) 2002 ARM Ltd.
* Copyright (C) 2008 STMicroelctronics.
* Copyright (C) 2009 ST-Ericsson.
* Author: Srinidhi Kasagar <srinidhi.kasagar@stericsson.com>
*
* This file is based on arm realview platform
*
* 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/init.h>
#include <linux/errno.h>
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/smp.h>
#include <linux/io.h>
#include <asm/cacheflush.h>
#include <asm/smp_plat.h>
#include <asm/smp_scu.h>
#include "setup.h"
#include "db8500-regs.h"
#include "id.h"
/* This is called from headsmp.S to wakeup the secondary core */
extern void u8500_secondary_startup(void);
/*
* Write pen_release in a way that is guaranteed to be visible to all
* observers, irrespective of whether they're taking part in coherency
* or not. This is necessary for the hotplug code to work reliably.
*/
static void write_pen_release(int val)
{
pen_release = val;
smp_wmb();
sync_cache_w(&pen_release);
}
static void __iomem *scu_base_addr(void)
{
if (cpu_is_u8500_family() || cpu_is_ux540_family())
return __io_address(U8500_SCU_BASE);
else
ux500_unknown_soc();
return NULL;
}
static DEFINE_SPINLOCK(boot_lock);
static void ux500_secondary_init(unsigned int cpu)
{
/*
* let the primary processor know we're out of the
* pen, then head off into the C entry point
*/
write_pen_release(-1);
/*
* Synchronise with the boot thread.
*/
spin_lock(&boot_lock);
spin_unlock(&boot_lock);
}
static int ux500_boot_secondary(unsigned int cpu, struct task_struct *idle)
{
unsigned long timeout;
/*
* set synchronisation state between this boot processor
* and the secondary one
*/
spin_lock(&boot_lock);
/*
* The secondary processor is waiting to be released from
* the holding pen - release it, then wait for it to flag
* that it has been released by resetting pen_release.
*/
write_pen_release(cpu_logical_map(cpu));
arch_send_wakeup_ipi_mask(cpumask_of(cpu));
timeout = jiffies + (1 * HZ);
while (time_before(jiffies, timeout)) {
if (pen_release == -1)
break;
}
/*
* now the secondary core is starting up let it run its
* calibrations, then wait for it to finish
*/
spin_unlock(&boot_lock);
return pen_release != -1 ? -ENOSYS : 0;
}
static void __init wakeup_secondary(void)
{
void __iomem *backupram;
if (cpu_is_u8500_family() || cpu_is_ux540_family())
backupram = __io_address(U8500_BACKUPRAM0_BASE);
else
ux500_unknown_soc();
/*
* write the address of secondary startup into the backup ram register
* at offset 0x1FF4, then write the magic number 0xA1FEED01 to the
* backup ram register at offset 0x1FF0, which is what boot rom code
* is waiting for. This would wake up the secondary core from WFE
*/
#define UX500_CPU1_JUMPADDR_OFFSET 0x1FF4
__raw_writel(virt_to_phys(u8500_secondary_startup),
backupram + UX500_CPU1_JUMPADDR_OFFSET);
#define UX500_CPU1_WAKEMAGIC_OFFSET 0x1FF0
__raw_writel(0xA1FEED01,
backupram + UX500_CPU1_WAKEMAGIC_OFFSET);
/* make sure write buffer is drained */
mb();
}
/*
* Initialise the CPU possible map early - this describes the CPUs
* which may be present or become present in the system.
*/
static void __init ux500_smp_init_cpus(void)
{
void __iomem *scu_base = scu_base_addr();
unsigned int i, ncores;
ncores = scu_base ? scu_get_core_count(scu_base) : 1;
/* sanity check */
if (ncores > nr_cpu_ids) {
pr_warn("SMP: %u cores greater than maximum (%u), clipping\n",
ncores, nr_cpu_ids);
ncores = nr_cpu_ids;
}
for (i = 0; i < ncores; i++)
set_cpu_possible(i, true);
}
static void __init ux500_smp_prepare_cpus(unsigned int max_cpus)
{
scu_enable(scu_base_addr());
wakeup_secondary();
}
struct smp_operations ux500_smp_ops __initdata = {
.smp_init_cpus = ux500_smp_init_cpus,
.smp_prepare_cpus = ux500_smp_prepare_cpus,
.smp_secondary_init = ux500_secondary_init,
.smp_boot_secondary = ux500_boot_secondary,
#ifdef CONFIG_HOTPLUG_CPU
.cpu_die = ux500_cpu_die,
#endif
};