98 lines
2.3 KiB
C
98 lines
2.3 KiB
C
/*
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* Sunxi platform smp source file.
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* It contains platform specific fucntions needed for the linux smp kernel.
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*
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* Copyright (c) Allwinner. All rights reserved.
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* Sugar (shuge@allwinnertech.com)
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*/
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#include <linux/delay.h>
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#include <asm/cacheflush.h>
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#include <asm/io.h>
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#include "platsmp.h"
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static cpumask_t dead_cpus;
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int sunxi_cpu_kill(unsigned int cpu)
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{
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int k, tmp_cpu = get_cpu();
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put_cpu();
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pr_debug("%s: cpu%d try to kill cpu%d\n", __func__, tmp_cpu, cpu);
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for (k = 0; k < 1000; k++) {
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if (cpumask_test_cpu(cpu, &dead_cpus)) {
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if (sunxi_is_wfi_mode(cpu)) {
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sunxi_disable_cpu(cpu);
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pr_debug("%s: cpu%d is killed!\n",
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__func__, cpu);
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#ifdef CONFIG_ARM_SUNXI_CPUIDLE
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sunxi_idle_cpux_flag_valid(cpu, 1);
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#endif
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return 1;
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}
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}
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mdelay(1);
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}
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pr_err("%s: try to kill cpu%d failed!\n", __func__, cpu);
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return 0;
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}
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int sunxi_cpu_disable(unsigned int cpu)
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{
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cpumask_clear_cpu(cpu, &dead_cpus);
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return cpu == 0 ? -EPERM : 0;
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}
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void sunxi_cpu_die(unsigned int cpu)
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{
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unsigned long actlr;
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cpumask_set_cpu(cpu, &dead_cpus);
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#ifdef CONFIG_ARM_SUNXI_CPUIDLE
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sunxi_idle_cpux_flag_set(cpu, 1);
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#endif
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/* step1: disable the data cache */
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asm("mrc p15, 0, %0, c1, c0, 0" : "=r" (actlr));
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actlr &= ~(1<<2);
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asm volatile("mcr p15, 0, %0, c1, c0, 0\n" : : "r" (actlr));
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/* step2: clean and ivalidate L1 cache */
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flush_cache_all();
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/* step3: execute a CLREX instruction */
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asm("clrex" : : : "memory", "cc");
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/* step4: switch cpu from SMP mode to AMP mode,
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* aim is to disable cache coherency
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*/
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asm("mrc p15, 0, %0, c1, c0, 1" : "=r" (actlr));
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actlr &= ~(1<<6);
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asm volatile("mcr p15, 0, %0, c1, c0, 1\n" : : "r" (actlr));
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/* step5: execute an ISB instruction */
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isb();
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/* step6: execute a DSB instruction */
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dsb();
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/* step7: execute a WFI instruction */
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while (1)
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asm("wfi" : : : "memory", "cc");
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}
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