xref: /openbmc/linux/arch/arm/common/mcpm_platsmp.c (revision 7b6d864b)
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 int __cpuinit mcpm_boot_secondary(unsigned int cpu, struct task_struct *idle)
23 {
24 	unsigned int mpidr, pcpu, pcluster, ret;
25 	extern void secondary_startup(void);
26 
27 	mpidr = cpu_logical_map(cpu);
28 	pcpu = MPIDR_AFFINITY_LEVEL(mpidr, 0);
29 	pcluster = MPIDR_AFFINITY_LEVEL(mpidr, 1);
30 	pr_debug("%s: logical CPU %d is physical CPU %d cluster %d\n",
31 		 __func__, cpu, pcpu, pcluster);
32 
33 	mcpm_set_entry_vector(pcpu, pcluster, NULL);
34 	ret = mcpm_cpu_power_up(pcpu, pcluster);
35 	if (ret)
36 		return ret;
37 	mcpm_set_entry_vector(pcpu, pcluster, secondary_startup);
38 	arch_send_wakeup_ipi_mask(cpumask_of(cpu));
39 	dsb_sev();
40 	return 0;
41 }
42 
43 static void __cpuinit mcpm_secondary_init(unsigned int cpu)
44 {
45 	mcpm_cpu_powered_up();
46 }
47 
48 #ifdef CONFIG_HOTPLUG_CPU
49 
50 static int mcpm_cpu_disable(unsigned int cpu)
51 {
52 	/*
53 	 * We assume all CPUs may be shut down.
54 	 * This would be the hook to use for eventual Secure
55 	 * OS migration requests as described in the PSCI spec.
56 	 */
57 	return 0;
58 }
59 
60 static void mcpm_cpu_die(unsigned int cpu)
61 {
62 	unsigned int mpidr, pcpu, pcluster;
63 	mpidr = read_cpuid_mpidr();
64 	pcpu = MPIDR_AFFINITY_LEVEL(mpidr, 0);
65 	pcluster = MPIDR_AFFINITY_LEVEL(mpidr, 1);
66 	mcpm_set_entry_vector(pcpu, pcluster, NULL);
67 	mcpm_cpu_power_down();
68 }
69 
70 #endif
71 
72 static struct smp_operations __initdata mcpm_smp_ops = {
73 	.smp_boot_secondary	= mcpm_boot_secondary,
74 	.smp_secondary_init	= mcpm_secondary_init,
75 #ifdef CONFIG_HOTPLUG_CPU
76 	.cpu_disable		= mcpm_cpu_disable,
77 	.cpu_die		= mcpm_cpu_die,
78 #endif
79 };
80 
81 void __init mcpm_smp_set_ops(void)
82 {
83 	smp_set_ops(&mcpm_smp_ops);
84 }
85