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
cpu_to_pcpu(unsigned int cpu,unsigned int * pcpu,unsigned int * pcluster)22 static void cpu_to_pcpu(unsigned int cpu,
23 unsigned int *pcpu, unsigned int *pcluster)
24 {
25 unsigned int mpidr;
26
27 mpidr = cpu_logical_map(cpu);
28 *pcpu = MPIDR_AFFINITY_LEVEL(mpidr, 0);
29 *pcluster = MPIDR_AFFINITY_LEVEL(mpidr, 1);
30 }
31
mcpm_boot_secondary(unsigned int cpu,struct task_struct * idle)32 static int mcpm_boot_secondary(unsigned int cpu, struct task_struct *idle)
33 {
34 unsigned int pcpu, pcluster, ret;
35 extern void secondary_startup(void);
36
37 cpu_to_pcpu(cpu, &pcpu, &pcluster);
38
39 pr_debug("%s: logical CPU %d is physical CPU %d cluster %d\n",
40 __func__, cpu, pcpu, pcluster);
41
42 mcpm_set_entry_vector(pcpu, pcluster, NULL);
43 ret = mcpm_cpu_power_up(pcpu, pcluster);
44 if (ret)
45 return ret;
46 mcpm_set_entry_vector(pcpu, pcluster, secondary_startup);
47 arch_send_wakeup_ipi_mask(cpumask_of(cpu));
48 dsb_sev();
49 return 0;
50 }
51
mcpm_secondary_init(unsigned int cpu)52 static void mcpm_secondary_init(unsigned int cpu)
53 {
54 mcpm_cpu_powered_up();
55 }
56
57 #ifdef CONFIG_HOTPLUG_CPU
58
mcpm_cpu_kill(unsigned int cpu)59 static int mcpm_cpu_kill(unsigned int cpu)
60 {
61 unsigned int pcpu, pcluster;
62
63 cpu_to_pcpu(cpu, &pcpu, &pcluster);
64
65 return !mcpm_wait_for_cpu_powerdown(pcpu, pcluster);
66 }
67
mcpm_cpu_can_disable(unsigned int cpu)68 static bool mcpm_cpu_can_disable(unsigned int cpu)
69 {
70 /* We assume all CPUs may be shut down. */
71 return true;
72 }
73
mcpm_cpu_die(unsigned int cpu)74 static void mcpm_cpu_die(unsigned int cpu)
75 {
76 unsigned int mpidr, pcpu, pcluster;
77 mpidr = read_cpuid_mpidr();
78 pcpu = MPIDR_AFFINITY_LEVEL(mpidr, 0);
79 pcluster = MPIDR_AFFINITY_LEVEL(mpidr, 1);
80 mcpm_set_entry_vector(pcpu, pcluster, NULL);
81 mcpm_cpu_power_down();
82 }
83
84 #endif
85
86 static const struct smp_operations mcpm_smp_ops __initconst = {
87 .smp_boot_secondary = mcpm_boot_secondary,
88 .smp_secondary_init = mcpm_secondary_init,
89 #ifdef CONFIG_HOTPLUG_CPU
90 .cpu_kill = mcpm_cpu_kill,
91 .cpu_can_disable = mcpm_cpu_can_disable,
92 .cpu_die = mcpm_cpu_die,
93 #endif
94 };
95
mcpm_smp_set_ops(void)96 void __init mcpm_smp_set_ops(void)
97 {
98 smp_set_ops(&mcpm_smp_ops);
99 }
100
