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90 lines
2.2 KiB
90 lines
2.2 KiB
// SPDX-License-Identifier: GPL-2.0 |
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/* |
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* SMP support for SoCs with SCU covered by mach-shmobile |
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* |
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* Copyright (C) 2013 Magnus Damm |
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*/ |
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#include <linux/cpu.h> |
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#include <linux/delay.h> |
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#include <linux/init.h> |
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#include <linux/io.h> |
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#include <linux/smp.h> |
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#include <asm/cacheflush.h> |
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#include <asm/smp_plat.h> |
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#include <asm/smp_scu.h> |
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#include "common.h" |
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static phys_addr_t shmobile_scu_base_phys; |
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static void __iomem *shmobile_scu_base; |
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static int shmobile_scu_cpu_prepare(unsigned int cpu) |
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{ |
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/* For this particular CPU register SCU SMP boot vector */ |
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shmobile_smp_hook(cpu, __pa_symbol(shmobile_boot_scu), |
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shmobile_scu_base_phys); |
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return 0; |
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} |
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void __init shmobile_smp_scu_prepare_cpus(phys_addr_t scu_base_phys, |
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unsigned int max_cpus) |
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{ |
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/* install boot code shared by all CPUs */ |
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shmobile_boot_fn = __pa_symbol(shmobile_smp_boot); |
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/* enable SCU and cache coherency on booting CPU */ |
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shmobile_scu_base_phys = scu_base_phys; |
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shmobile_scu_base = ioremap(scu_base_phys, PAGE_SIZE); |
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scu_enable(shmobile_scu_base); |
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scu_power_mode(shmobile_scu_base, SCU_PM_NORMAL); |
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/* Use CPU notifier for reset vector control */ |
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cpuhp_setup_state_nocalls(CPUHP_ARM_SHMOBILE_SCU_PREPARE, |
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"arm/shmobile-scu:prepare", |
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shmobile_scu_cpu_prepare, NULL); |
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} |
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#ifdef CONFIG_HOTPLUG_CPU |
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void shmobile_smp_scu_cpu_die(unsigned int cpu) |
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{ |
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/* For this particular CPU deregister boot vector */ |
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shmobile_smp_hook(cpu, 0, 0); |
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dsb(); |
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flush_cache_all(); |
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/* disable cache coherency */ |
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scu_power_mode(shmobile_scu_base, SCU_PM_POWEROFF); |
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/* jump to shared mach-shmobile sleep / reset code */ |
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shmobile_smp_sleep(); |
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} |
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static int shmobile_smp_scu_psr_core_disabled(int cpu) |
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{ |
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unsigned long mask = SCU_PM_POWEROFF << (cpu * 8); |
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if ((readl(shmobile_scu_base + 8) & mask) == mask) |
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return 1; |
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return 0; |
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} |
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int shmobile_smp_scu_cpu_kill(unsigned int cpu) |
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{ |
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int k; |
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/* this function is running on another CPU than the offline target, |
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* here we need wait for shutdown code in platform_cpu_die() to |
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* finish before asking SoC-specific code to power off the CPU core. |
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*/ |
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for (k = 0; k < 1000; k++) { |
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if (shmobile_smp_scu_psr_core_disabled(cpu)) |
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return 1; |
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mdelay(1); |
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} |
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return 0; |
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} |
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#endif
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