projects / linux-2.6-block.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> | |
| 18 | #include <mach/common.h> | |
| 19 | ||
| 916d6121 MD |
20 | static int shmobile_smp_scu_notifier_call(struct notifier_block *nfb, |
| 21 | unsigned long action, void *hcpu) | |
| 22 | { | |
| 23 | unsigned int cpu = (long)hcpu; | |
| 24 | ||
| 25 | switch (action) { | |
| 26 | case CPU_UP_PREPARE: | |
| 27 | /* For this particular CPU register SCU SMP boot vector */ | |
| 28 | shmobile_smp_hook(cpu, virt_to_phys(shmobile_boot_scu), | |
| 29 | (unsigned long)shmobile_scu_base); | |
| 30 | break; | |
| 31 | }; | |
| 32 | ||
| 33 | return NOTIFY_OK; | |
| 34 | } | |
| 35 | ||
| 36 | static struct notifier_block shmobile_smp_scu_notifier = { | |
| 37 | .notifier_call = shmobile_smp_scu_notifier_call, | |
| 38 | }; | |
| 39 | ||
| c970d4ef MD |
40 | void __init shmobile_smp_scu_prepare_cpus(unsigned int max_cpus) |
| 41 | { | |
| 1d33a354 MD |
42 | /* install boot code shared by all CPUs */ |
| 43 | shmobile_boot_fn = virt_to_phys(shmobile_smp_boot); | |
| 44 | shmobile_boot_arg = MPIDR_HWID_BITMASK; | |
| c970d4ef MD |
45 | |
| 46 | /* enable SCU and cache coherency on booting CPU */ | |
| 47 | scu_enable(shmobile_scu_base); | |
| 48 | scu_power_mode(shmobile_scu_base, SCU_PM_NORMAL); | |
| 916d6121 MD |
49 | |
| 50 | /* Use CPU notifier for reset vector control */ | |
| 51 | register_cpu_notifier(&shmobile_smp_scu_notifier); | |
| c970d4ef MD |
52 | } |
| 53 | ||
| 54 | int shmobile_smp_scu_boot_secondary(unsigned int cpu, struct task_struct *idle) | |
| 55 | { | |
| 1d33a354 MD |
56 | /* For this particular CPU register SCU boot vector */ |
| 57 | shmobile_smp_hook(cpu, virt_to_phys(shmobile_boot_scu), | |
| 58 | (unsigned long)shmobile_scu_base); | |
| c970d4ef MD |
59 | return 0; |
| 60 | } | |
| e7b1c963 MD |
61 | |
| 62 | #ifdef CONFIG_HOTPLUG_CPU | |
| 63 | void shmobile_smp_scu_cpu_die(unsigned int cpu) | |
| 64 | { | |
| 1d33a354 MD |
65 | /* For this particular CPU deregister boot vector */ |
| 66 | shmobile_smp_hook(cpu, 0, 0); | |
| 67 | ||
| e7b1c963 MD |
68 | dsb(); |
| 69 | flush_cache_all(); | |
| 70 | ||
| 71 | /* disable cache coherency */ | |
| 72 | scu_power_mode(shmobile_scu_base, SCU_PM_POWEROFF); | |
| 73 | ||
| 1d33a354 MD |
74 | /* jump to shared mach-shmobile sleep / reset code */ |
| 75 | shmobile_smp_sleep(); | |
| e7b1c963 MD |
76 | } |
| 77 | ||
| 78 | static int shmobile_smp_scu_psr_core_disabled(int cpu) | |
| 79 | { | |
| 80 | unsigned long mask = SCU_PM_POWEROFF << (cpu * 8); | |
| 81 | ||
| 82 | if ((__raw_readl(shmobile_scu_base + 8) & mask) == mask) | |
| 83 | return 1; | |
| 84 | ||
| 85 | return 0; | |
| 86 | } | |
| 87 | ||
| 88 | int shmobile_smp_scu_cpu_kill(unsigned int cpu) | |
| 89 | { | |
| 90 | int k; | |
| 91 | ||
| 92 | /* this function is running on another CPU than the offline target, | |
| 93 | * here we need wait for shutdown code in platform_cpu_die() to | |
| 94 | * finish before asking SoC-specific code to power off the CPU core. | |
| 95 | */ | |
| 96 | for (k = 0; k < 1000; k++) { | |
| 97 | if (shmobile_smp_scu_psr_core_disabled(cpu)) | |
| 98 | return 1; | |
| 99 | ||
| 100 | mdelay(1); | |
| 101 | } | |
| 102 | ||
| 103 | return 0; | |
| 104 | } | |
| 105 | #endif |