1 /* 2 * SMP support for SoCs with SCU covered by mach-shmobile 3 * 4 * Copyright (C) 2013 Magnus Damm 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License version 2 as 8 * published by the Free Software Foundation. 9 */ 10 #include <linux/delay.h> 11 #include <linux/init.h> 12 #include <linux/io.h> 13 #include <linux/smp.h> 14 #include <asm/cacheflush.h> 15 #include <asm/smp_plat.h> 16 #include <asm/smp_scu.h> 17 #include <mach/common.h> 18 19 void __init shmobile_smp_scu_prepare_cpus(unsigned int max_cpus) 20 { 21 /* install boot code shared by all CPUs */ 22 shmobile_boot_fn = virt_to_phys(shmobile_smp_boot); 23 shmobile_boot_arg = MPIDR_HWID_BITMASK; 24 25 /* enable SCU and cache coherency on booting CPU */ 26 scu_enable(shmobile_scu_base); 27 scu_power_mode(shmobile_scu_base, SCU_PM_NORMAL); 28 } 29 30 int shmobile_smp_scu_boot_secondary(unsigned int cpu, struct task_struct *idle) 31 { 32 /* For this particular CPU register SCU boot vector */ 33 shmobile_smp_hook(cpu, virt_to_phys(shmobile_boot_scu), 34 (unsigned long)shmobile_scu_base); 35 return 0; 36 } 37 38 #ifdef CONFIG_HOTPLUG_CPU 39 void shmobile_smp_scu_cpu_die(unsigned int cpu) 40 { 41 /* For this particular CPU deregister boot vector */ 42 shmobile_smp_hook(cpu, 0, 0); 43 44 dsb(); 45 flush_cache_all(); 46 47 /* disable cache coherency */ 48 scu_power_mode(shmobile_scu_base, SCU_PM_POWEROFF); 49 50 /* jump to shared mach-shmobile sleep / reset code */ 51 shmobile_smp_sleep(); 52 } 53 54 static int shmobile_smp_scu_psr_core_disabled(int cpu) 55 { 56 unsigned long mask = SCU_PM_POWEROFF << (cpu * 8); 57 58 if ((__raw_readl(shmobile_scu_base + 8) & mask) == mask) 59 return 1; 60 61 return 0; 62 } 63 64 int shmobile_smp_scu_cpu_kill(unsigned int cpu) 65 { 66 int k; 67 68 /* this function is running on another CPU than the offline target, 69 * here we need wait for shutdown code in platform_cpu_die() to 70 * finish before asking SoC-specific code to power off the CPU core. 71 */ 72 for (k = 0; k < 1000; k++) { 73 if (shmobile_smp_scu_psr_core_disabled(cpu)) 74 return 1; 75 76 mdelay(1); 77 } 78 79 return 0; 80 } 81 #endif 82