projects / deliverable / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| c970d4ef MD |
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 | */ | |
| 916d6121 | 10 | #include <linux/cpu.h> |
| e7b1c963 | 11 | #include <linux/delay.h> |
| c970d4ef MD |
12 | #include <linux/init.h> |
| 13 | #include <linux/io.h> | |
| 14 | #include <linux/smp.h> | |
| e7b1c963 | 15 | #include <asm/cacheflush.h> |
| c970d4ef MD |
16 | #include <asm/smp_plat.h> |
| 17 | #include <asm/smp_scu.h> | |
| fd44aa5e | 18 | #include "common.h" |
| c970d4ef | 19 | |
| d2613f56 | 20 | |
| 8701d808 GU |
21 | static phys_addr_t shmobile_scu_base_phys; |
| 22 | static void __iomem *shmobile_scu_base; | |
| d2613f56 | 23 | |
| 916d6121 MD |
24 | static int shmobile_smp_scu_notifier_call(struct notifier_block *nfb, |
| 25 | unsigned long action, void *hcpu) | |
| 26 | { | |
| 27 | unsigned int cpu = (long)hcpu; | |
| 28 | ||
| 29 | switch (action) { | |
| 30 | case CPU_UP_PREPARE: | |
| 31 | /* For this particular CPU register SCU SMP boot vector */ | |
| 32 | shmobile_smp_hook(cpu, virt_to_phys(shmobile_boot_scu), | |
| 8701d808 | 33 | shmobile_scu_base_phys); |
| 916d6121 MD |
34 | break; |
| 35 | }; | |
| 36 | ||
| 37 | return NOTIFY_OK; | |
| 38 | } | |
| 39 | ||
| 40 | static struct notifier_block shmobile_smp_scu_notifier = { | |
| 41 | .notifier_call = shmobile_smp_scu_notifier_call, | |
| 42 | }; | |
| 43 | ||
| 8701d808 GU |
44 | void __init shmobile_smp_scu_prepare_cpus(phys_addr_t scu_base_phys, |
| 45 | unsigned int max_cpus) | |
| c970d4ef | 46 | { |
| 1d33a354 MD |
47 | /* install boot code shared by all CPUs */ |
| 48 | shmobile_boot_fn = virt_to_phys(shmobile_smp_boot); | |
| c970d4ef MD |
49 | |
| 50 | /* enable SCU and cache coherency on booting CPU */ | |
| 8701d808 GU |
51 | shmobile_scu_base_phys = scu_base_phys; |
| 52 | shmobile_scu_base = ioremap(scu_base_phys, PAGE_SIZE); | |
| c970d4ef MD |
53 | scu_enable(shmobile_scu_base); |
| 54 | scu_power_mode(shmobile_scu_base, SCU_PM_NORMAL); | |
| 916d6121 MD |
55 | |
| 56 | /* Use CPU notifier for reset vector control */ | |
| 57 | register_cpu_notifier(&shmobile_smp_scu_notifier); | |
| c970d4ef MD |
58 | } |
| 59 | ||
| e7b1c963 MD |
60 | #ifdef CONFIG_HOTPLUG_CPU |
| 61 | void shmobile_smp_scu_cpu_die(unsigned int cpu) | |
| 62 | { | |
| 1d33a354 MD |
63 | /* For this particular CPU deregister boot vector */ |
| 64 | shmobile_smp_hook(cpu, 0, 0); | |
| 65 | ||
| e7b1c963 MD |
66 | dsb(); |
| 67 | flush_cache_all(); | |
| 68 | ||
| 69 | /* disable cache coherency */ | |
| 70 | scu_power_mode(shmobile_scu_base, SCU_PM_POWEROFF); | |
| 71 | ||
| 1d33a354 MD |
72 | /* jump to shared mach-shmobile sleep / reset code */ |
| 73 | shmobile_smp_sleep(); | |
| e7b1c963 MD |
74 | } |
| 75 | ||
| 76 | static int shmobile_smp_scu_psr_core_disabled(int cpu) | |
| 77 | { | |
| 78 | unsigned long mask = SCU_PM_POWEROFF << (cpu * 8); | |
| 79 | ||
| 80 | if ((__raw_readl(shmobile_scu_base + 8) & mask) == mask) | |
| 81 | return 1; | |
| 82 | ||
| 83 | return 0; | |
| 84 | } | |
| 85 | ||
| 86 | int shmobile_smp_scu_cpu_kill(unsigned int cpu) | |
| 87 | { | |
| 88 | int k; | |
| 89 | ||
| 90 | /* this function is running on another CPU than the offline target, | |
| 91 | * here we need wait for shutdown code in platform_cpu_die() to | |
| 92 | * finish before asking SoC-specific code to power off the CPU core. | |
| 93 | */ | |
| 94 | for (k = 0; k < 1000; k++) { | |
| 95 | if (shmobile_smp_scu_psr_core_disabled(cpu)) | |
| 96 | return 1; | |
| 97 | ||
| 98 | mdelay(1); | |
| 99 | } | |
| 100 | ||
| 101 | return 0; | |
| 102 | } | |
| 103 | #endif |