/*
|
* 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.
|
*/
|
|
#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)) {
|
sunxi_disable_cpu(cpu);
|
pr_debug("%s: cpu%d is killed!\n",
|
__func__, cpu);
|
#ifdef CONFIG_ARM_SUNXI_CPUIDLE
|
sunxi_idle_cpux_flag_valid(cpu, 1);
|
#endif
|
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);
|
|
#ifdef CONFIG_ARM_SUNXI_CPUIDLE
|
sunxi_idle_cpux_flag_set(cpu, 1);
|
#endif
|
|
/* 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");
|
}
|
