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 | |
657ebf7a | 24 | static int shmobile_scu_cpu_prepare(unsigned int cpu) |
916d6121 | 25 | { |
657ebf7a SAS |
26 | /* For this particular CPU register SCU SMP boot vector */ |
27 | shmobile_smp_hook(cpu, virt_to_phys(shmobile_boot_scu), | |
28 | shmobile_scu_base_phys); | |
29 | return 0; | |
916d6121 MD |
30 | } |
31 | ||
8701d808 GU |
32 | void __init shmobile_smp_scu_prepare_cpus(phys_addr_t scu_base_phys, |
33 | unsigned int max_cpus) | |
c970d4ef | 34 | { |
1d33a354 MD |
35 | /* install boot code shared by all CPUs */ |
36 | shmobile_boot_fn = virt_to_phys(shmobile_smp_boot); | |
c970d4ef MD |
37 | |
38 | /* enable SCU and cache coherency on booting CPU */ | |
8701d808 GU |
39 | shmobile_scu_base_phys = scu_base_phys; |
40 | shmobile_scu_base = ioremap(scu_base_phys, PAGE_SIZE); | |
c970d4ef MD |
41 | scu_enable(shmobile_scu_base); |
42 | scu_power_mode(shmobile_scu_base, SCU_PM_NORMAL); | |
916d6121 MD |
43 | |
44 | /* Use CPU notifier for reset vector control */ | |
657ebf7a SAS |
45 | cpuhp_setup_state_nocalls(CPUHP_ARM_SHMOBILE_SCU_PREPARE, |
46 | "arm/shmobile-scu:prepare", | |
47 | shmobile_scu_cpu_prepare, NULL); | |
c970d4ef MD |
48 | } |
49 | ||
e7b1c963 MD |
50 | #ifdef CONFIG_HOTPLUG_CPU |
51 | void shmobile_smp_scu_cpu_die(unsigned int cpu) | |
52 | { | |
1d33a354 MD |
53 | /* For this particular CPU deregister boot vector */ |
54 | shmobile_smp_hook(cpu, 0, 0); | |
55 | ||
e7b1c963 MD |
56 | dsb(); |
57 | flush_cache_all(); | |
58 | ||
59 | /* disable cache coherency */ | |
60 | scu_power_mode(shmobile_scu_base, SCU_PM_POWEROFF); | |
61 | ||
1d33a354 MD |
62 | /* jump to shared mach-shmobile sleep / reset code */ |
63 | shmobile_smp_sleep(); | |
e7b1c963 MD |
64 | } |
65 | ||
66 | static int shmobile_smp_scu_psr_core_disabled(int cpu) | |
67 | { | |
68 | unsigned long mask = SCU_PM_POWEROFF << (cpu * 8); | |
69 | ||
70 | if ((__raw_readl(shmobile_scu_base + 8) & mask) == mask) | |
71 | return 1; | |
72 | ||
73 | return 0; | |
74 | } | |
75 | ||
76 | int shmobile_smp_scu_cpu_kill(unsigned int cpu) | |
77 | { | |
78 | int k; | |
79 | ||
80 | /* this function is running on another CPU than the offline target, | |
81 | * here we need wait for shutdown code in platform_cpu_die() to | |
82 | * finish before asking SoC-specific code to power off the CPU core. | |
83 | */ | |
84 | for (k = 0; k < 1000; k++) { | |
85 | if (shmobile_smp_scu_psr_core_disabled(cpu)) | |
86 | return 1; | |
87 | ||
88 | mdelay(1); | |
89 | } | |
90 | ||
91 | return 0; | |
92 | } | |
93 | #endif |