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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 | /* * SMP support for SoCs with SCU covered by mach-shmobile * * Copyright (C) 2013 Magnus Damm * * 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. */ #include <linux/cpu.h> #include <linux/delay.h> #include <linux/init.h> #include <linux/io.h> #include <linux/smp.h> #include <asm/cacheflush.h> #include <asm/smp_plat.h> #include <asm/smp_scu.h> #include "common.h" static phys_addr_t shmobile_scu_base_phys; static void __iomem *shmobile_scu_base; static int shmobile_smp_scu_notifier_call(struct notifier_block *nfb, unsigned long action, void *hcpu) { unsigned int cpu = (long)hcpu; switch (action) { case CPU_UP_PREPARE: /* For this particular CPU register SCU SMP boot vector */ shmobile_smp_hook(cpu, virt_to_phys(shmobile_boot_scu), shmobile_scu_base_phys); break; }; return NOTIFY_OK; } static struct notifier_block shmobile_smp_scu_notifier = { .notifier_call = shmobile_smp_scu_notifier_call, }; void __init shmobile_smp_scu_prepare_cpus(phys_addr_t scu_base_phys, unsigned int max_cpus) { /* install boot code shared by all CPUs */ shmobile_boot_fn = virt_to_phys(shmobile_smp_boot); /* enable SCU and cache coherency on booting CPU */ shmobile_scu_base_phys = scu_base_phys; shmobile_scu_base = ioremap(scu_base_phys, PAGE_SIZE); scu_enable(shmobile_scu_base); scu_power_mode(shmobile_scu_base, SCU_PM_NORMAL); /* Use CPU notifier for reset vector control */ register_cpu_notifier(&shmobile_smp_scu_notifier); } #ifdef CONFIG_HOTPLUG_CPU void shmobile_smp_scu_cpu_die(unsigned int cpu) { /* For this particular CPU deregister boot vector */ shmobile_smp_hook(cpu, 0, 0); dsb(); flush_cache_all(); /* disable cache coherency */ scu_power_mode(shmobile_scu_base, SCU_PM_POWEROFF); /* jump to shared mach-shmobile sleep / reset code */ shmobile_smp_sleep(); } static int shmobile_smp_scu_psr_core_disabled(int cpu) { unsigned long mask = SCU_PM_POWEROFF << (cpu * 8); if ((__raw_readl(shmobile_scu_base + 8) & mask) == mask) return 1; return 0; } int shmobile_smp_scu_cpu_kill(unsigned int cpu) { int k; /* this function is running on another CPU than the offline target, * here we need wait for shutdown code in platform_cpu_die() to * finish before asking SoC-specific code to power off the CPU core. */ for (k = 0; k < 1000; k++) { if (shmobile_smp_scu_psr_core_disabled(cpu)) return 1; mdelay(1); } return 0; } #endif |