TERES/SOFTWARE/A64-TERES/linux-a64/arch/arm/mach-sunxi/hotplug.c
Dimitar Gamishev f9b0e7a283 linux
2017-10-13 14:07:04 +03:00

95 lines
2.4 KiB
C

/*
* Sunxi platform smp source file.
* It contains platform specific fucntions needed for the linux smp kernel.
*
* Copyright (c) Allwinner. All rights reserved.
* Sugar (shuge@allwinnertech.com)
*
* 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; either version 2 of the License, or
* (at your option) any later version.
*
* 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <linux/delay.h>
#include <asm/cacheflush.h>
#include <asm/io.h>
#include "platsmp.h"
static cpumask_t dead_cpus;
int sunxi_cpu_kill(unsigned int cpu)
{
int k, tmp_cpu = get_cpu();
put_cpu();
pr_debug("%s: cpu%d try to kill cpu%d\n", __func__, tmp_cpu, cpu);
for (k = 0; k < 1000; k++) {
if (cpumask_test_cpu(cpu, &dead_cpus)) {
if (sunxi_is_wfi_mode(cpu)) {
#ifndef CONFIG_ARCH_SUN8IW10
sunxi_disable_cpu(cpu);
#endif
pr_debug("%s: cpu%d is killed!\n", __func__, cpu);
return 1;
}
}
mdelay(1);
}
pr_err("%s: try to kill cpu%d failed!\n", __func__, cpu);
return 0;
}
int sunxi_cpu_disable(unsigned int cpu)
{
cpumask_clear_cpu(cpu, &dead_cpus);
return cpu == 0 ? -EPERM : 0;
}
void sunxi_cpu_die(unsigned int cpu)
{
unsigned long actlr;
cpumask_set_cpu(cpu, &dead_cpus);
/* step1: disable the data cache */
asm("mrc p15, 0, %0, c1, c0, 0" : "=r" (actlr) );
actlr &= ~(1<<2);
asm volatile("mcr p15, 0, %0, c1, c0, 0\n" : : "r" (actlr));
/* step2: clean and ivalidate L1 cache */
flush_cache_all();
/* step3: execute a CLREX instruction */
asm("clrex" : : : "memory", "cc");
/* step4: switch cpu from SMP mode to AMP mode, aim is to disable cache coherency */
asm("mrc p15, 0, %0, c1, c0, 1" : "=r" (actlr) );
actlr &= ~(1<<6);
asm volatile("mcr p15, 0, %0, c1, c0, 1\n" : : "r" (actlr));
/* step5: execute an ISB instruction */
isb();
/* step6: execute a DSB instruction */
dsb();
/* step7: execute a WFI instruction */
while (1) {
asm("wfi" : : : "memory", "cc");
}
}