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