linux-sg2042/arch/arm64/kernel/smp_spin_table.c

67 lines
1.6 KiB
C

/*
* Spin Table SMP initialisation
*
* Copyright (C) 2013 ARM Ltd.
*
* 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.
*
* 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, see <http://www.gnu.org/licenses/>.
*/
#include <linux/init.h>
#include <linux/of.h>
#include <linux/smp.h>
#include <asm/cacheflush.h>
static phys_addr_t cpu_release_addr[NR_CPUS];
static int __init smp_spin_table_init_cpu(struct device_node *dn, int cpu)
{
/*
* Determine the address from which the CPU is polling.
*/
if (of_property_read_u64(dn, "cpu-release-addr",
&cpu_release_addr[cpu])) {
pr_err("CPU %d: missing or invalid cpu-release-addr property\n",
cpu);
return -1;
}
return 0;
}
static int __init smp_spin_table_prepare_cpu(int cpu)
{
void **release_addr;
if (!cpu_release_addr[cpu])
return -ENODEV;
release_addr = __va(cpu_release_addr[cpu]);
release_addr[0] = (void *)__pa(secondary_holding_pen);
__flush_dcache_area(release_addr, sizeof(release_addr[0]));
/*
* Send an event to wake up the secondary CPU.
*/
sev();
return 0;
}
const struct smp_enable_ops smp_spin_table_ops __initconst = {
.name = "spin-table",
.init_cpu = smp_spin_table_init_cpu,
.prepare_cpu = smp_spin_table_prepare_cpu,
};