2 * SMP support for SoCs with SCU covered by mach-shmobile
4 * Copyright (C) 2013 Magnus Damm
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.
10 #include <linux/cpu.h>
11 #include <linux/delay.h>
12 #include <linux/init.h>
14 #include <linux/smp.h>
15 #include <asm/cacheflush.h>
16 #include <asm/smp_plat.h>
17 #include <asm/smp_scu.h>
21 static phys_addr_t shmobile_scu_base_phys;
22 static void __iomem *shmobile_scu_base;
24 static int shmobile_smp_scu_notifier_call(struct notifier_block *nfb,
25 unsigned long action, void *hcpu)
27 unsigned int cpu = (long)hcpu;
31 /* For this particular CPU register SCU SMP boot vector */
32 shmobile_smp_hook(cpu, virt_to_phys(shmobile_boot_scu),
33 shmobile_scu_base_phys);
40 static struct notifier_block shmobile_smp_scu_notifier = {
41 .notifier_call = shmobile_smp_scu_notifier_call,
44 void __init shmobile_smp_scu_prepare_cpus(phys_addr_t scu_base_phys,
45 unsigned int max_cpus)
47 /* install boot code shared by all CPUs */
48 shmobile_boot_fn = virt_to_phys(shmobile_smp_boot);
49 shmobile_boot_arg = MPIDR_HWID_BITMASK;
51 /* enable SCU and cache coherency on booting CPU */
52 shmobile_scu_base_phys = scu_base_phys;
53 shmobile_scu_base = ioremap(scu_base_phys, PAGE_SIZE);
54 scu_enable(shmobile_scu_base);
55 scu_power_mode(shmobile_scu_base, SCU_PM_NORMAL);
57 /* Use CPU notifier for reset vector control */
58 register_cpu_notifier(&shmobile_smp_scu_notifier);
61 #ifdef CONFIG_HOTPLUG_CPU
62 void shmobile_smp_scu_cpu_die(unsigned int cpu)
64 /* For this particular CPU deregister boot vector */
65 shmobile_smp_hook(cpu, 0, 0);
70 /* disable cache coherency */
71 scu_power_mode(shmobile_scu_base, SCU_PM_POWEROFF);
73 /* jump to shared mach-shmobile sleep / reset code */
77 static int shmobile_smp_scu_psr_core_disabled(int cpu)
79 unsigned long mask = SCU_PM_POWEROFF << (cpu * 8);
81 if ((__raw_readl(shmobile_scu_base + 8) & mask) == mask)
87 int shmobile_smp_scu_cpu_kill(unsigned int cpu)
91 /* this function is running on another CPU than the offline target,
92 * here we need wait for shutdown code in platform_cpu_die() to
93 * finish before asking SoC-specific code to power off the CPU core.
95 for (k = 0; k < 1000; k++) {
96 if (shmobile_smp_scu_psr_core_disabled(cpu))