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 |