xref: /openbmc/linux/arch/arm/common/mcpm_platsmp.c (revision 9e01573b)
1 /*
2  * linux/arch/arm/mach-vexpress/mcpm_platsmp.c
3  *
4  * Created by:  Nicolas Pitre, November 2012
5  * Copyright:   (C) 2012-2013  Linaro Limited
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License version 2 as
9  * published by the Free Software Foundation.
10  *
11  * Code to handle secondary CPU bringup and hotplug for the cluster power API.
12  */
13 
14 #include <linux/init.h>
15 #include <linux/smp.h>
16 #include <linux/spinlock.h>
17 
18 #include <asm/mcpm.h>
19 #include <asm/smp.h>
20 #include <asm/smp_plat.h>
21 
22 static void __init simple_smp_init_cpus(void)
23 {
24 }
25 
26 static int __cpuinit mcpm_boot_secondary(unsigned int cpu, struct task_struct *idle)
27 {
28 	unsigned int mpidr, pcpu, pcluster, ret;
29 	extern void secondary_startup(void);
30 
31 	mpidr = cpu_logical_map(cpu);
32 	pcpu = MPIDR_AFFINITY_LEVEL(mpidr, 0);
33 	pcluster = MPIDR_AFFINITY_LEVEL(mpidr, 1);
34 	pr_debug("%s: logical CPU %d is physical CPU %d cluster %d\n",
35 		 __func__, cpu, pcpu, pcluster);
36 
37 	mcpm_set_entry_vector(pcpu, pcluster, NULL);
38 	ret = mcpm_cpu_power_up(pcpu, pcluster);
39 	if (ret)
40 		return ret;
41 	mcpm_set_entry_vector(pcpu, pcluster, secondary_startup);
42 	arch_send_wakeup_ipi_mask(cpumask_of(cpu));
43 	dsb_sev();
44 	return 0;
45 }
46 
47 static void __cpuinit mcpm_secondary_init(unsigned int cpu)
48 {
49 	mcpm_cpu_powered_up();
50 }
51 
52 #ifdef CONFIG_HOTPLUG_CPU
53 
54 static int mcpm_cpu_disable(unsigned int cpu)
55 {
56 	/*
57 	 * We assume all CPUs may be shut down.
58 	 * This would be the hook to use for eventual Secure
59 	 * OS migration requests as described in the PSCI spec.
60 	 */
61 	return 0;
62 }
63 
64 static void mcpm_cpu_die(unsigned int cpu)
65 {
66 	unsigned int mpidr, pcpu, pcluster;
67 	mpidr = read_cpuid_mpidr();
68 	pcpu = MPIDR_AFFINITY_LEVEL(mpidr, 0);
69 	pcluster = MPIDR_AFFINITY_LEVEL(mpidr, 1);
70 	mcpm_set_entry_vector(pcpu, pcluster, NULL);
71 	mcpm_cpu_power_down();
72 }
73 
74 #endif
75 
76 static struct smp_operations __initdata mcpm_smp_ops = {
77 	.smp_init_cpus		= simple_smp_init_cpus,
78 	.smp_boot_secondary	= mcpm_boot_secondary,
79 	.smp_secondary_init	= mcpm_secondary_init,
80 #ifdef CONFIG_HOTPLUG_CPU
81 	.cpu_disable		= mcpm_cpu_disable,
82 	.cpu_die		= mcpm_cpu_die,
83 #endif
84 };
85 
86 void __init mcpm_smp_set_ops(void)
87 {
88 	smp_set_ops(&mcpm_smp_ops);
89 }
90