Loading...
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 | /*
* arch/arm/mach-sti/platsmp.c
*
* Copyright (C) 2013 STMicroelectronics (R&D) Limited.
* http://www.st.com
*
* Cloned from linux/arch/arm/mach-vexpress/platsmp.c
*
* Copyright (C) 2002 ARM Ltd.
* All Rights Reserved
*
* 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/smp.h>
#include <linux/io.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/memblock.h>
#include <asm/cacheflush.h>
#include <asm/smp_plat.h>
#include <asm/smp_scu.h>
#include "smp.h"
static void write_pen_release(int val)
{
pen_release = val;
smp_wmb();
sync_cache_w(&pen_release);
}
static DEFINE_SPINLOCK(boot_lock);
static void sti_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 sti_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.
*
* Note that "pen_release" is the hardware CPU ID, whereas
* "cpu" is Linux's internal ID.
*/
write_pen_release(cpu_logical_map(cpu));
/*
* Send the secondary CPU a soft interrupt, thereby causing
* it to jump to the secondary entrypoint.
*/
arch_send_wakeup_ipi_mask(cpumask_of(cpu));
timeout = jiffies + (1 * HZ);
while (time_before(jiffies, timeout)) {
smp_rmb();
if (pen_release == -1)
break;
udelay(10);
}
/*
* 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 sti_smp_prepare_cpus(unsigned int max_cpus)
{
struct device_node *np;
void __iomem *scu_base;
u32 __iomem *cpu_strt_ptr;
u32 release_phys;
int cpu;
unsigned long entry_pa = virt_to_phys(sti_secondary_startup);
np = of_find_compatible_node(NULL, NULL, "arm,cortex-a9-scu");
if (np) {
scu_base = of_iomap(np, 0);
scu_enable(scu_base);
of_node_put(np);
}
if (max_cpus <= 1)
return;
for_each_possible_cpu(cpu) {
np = of_get_cpu_node(cpu, NULL);
if (!np)
continue;
if (of_property_read_u32(np, "cpu-release-addr",
&release_phys)) {
pr_err("CPU %d: missing or invalid cpu-release-addr "
"property\n", cpu);
continue;
}
/*
* holding pen is usually configured in SBC DMEM but can also be
* in RAM.
*/
if (!memblock_is_memory(release_phys))
cpu_strt_ptr =
ioremap(release_phys, sizeof(release_phys));
else
cpu_strt_ptr =
(u32 __iomem *)phys_to_virt(release_phys);
__raw_writel(entry_pa, cpu_strt_ptr);
/*
* wmb so that data is actually written
* before cache flush is done
*/
smp_wmb();
sync_cache_w(cpu_strt_ptr);
if (!memblock_is_memory(release_phys))
iounmap(cpu_strt_ptr);
}
}
const struct smp_operations sti_smp_ops __initconst = {
.smp_prepare_cpus = sti_smp_prepare_cpus,
.smp_secondary_init = sti_secondary_init,
.smp_boot_secondary = sti_boot_secondary,
};
|