1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * linux/arch/arm/mach-vexpress/mcpm_platsmp.c
4 *
5 * Created by: Nicolas Pitre, November 2012
6 * Copyright: (C) 2012-2013 Linaro Limited
7 *
8 * Code to handle secondary CPU bringup and hotplug for the cluster power API.
9 */
10
11 #include <linux/init.h>
12 #include <linux/smp.h>
13 #include <linux/spinlock.h>
14
15 #include <asm/mcpm.h>
16 #include <asm/smp.h>
17 #include <asm/smp_plat.h>
18
19 static void cpu_to_pcpu(unsigned int cpu,
20 unsigned int *pcpu, unsigned int *pcluster)
21 {
22 unsigned int mpidr;
23
24 mpidr = cpu_logical_map(cpu);
25 *pcpu = MPIDR_AFFINITY_LEVEL(mpidr, 0);
26 *pcluster = MPIDR_AFFINITY_LEVEL(mpidr, 1);
27 }
28
29 static int mcpm_boot_secondary(unsigned int cpu, struct task_struct *idle)
30 {
31 unsigned int pcpu, pcluster, ret;
32 extern void secondary_startup(void);
33
34 cpu_to_pcpu(cpu, &pcpu, &pcluster);
35
36 pr_debug("%s: logical CPU %d is physical CPU %d cluster %d\n",
37 __func__, cpu, pcpu, pcluster);
38
39 mcpm_set_entry_vector(pcpu, pcluster, NULL);
40 ret = mcpm_cpu_power_up(pcpu, pcluster);
41 if (ret)
42 return ret;
43 mcpm_set_entry_vector(pcpu, pcluster, secondary_startup);
44 arch_send_wakeup_ipi_mask(cpumask_of(cpu));
45 dsb_sev();
46 return 0;
47 }
48
49 static void mcpm_secondary_init(unsigned int cpu)
50 {
51 mcpm_cpu_powered_up();
52 }
53
54 #ifdef CONFIG_HOTPLUG_CPU
55
56 static int mcpm_cpu_kill(unsigned int cpu)
57 {
58 unsigned int pcpu, pcluster;
59
60 cpu_to_pcpu(cpu, &pcpu, &pcluster);
61
62 return !mcpm_wait_for_cpu_powerdown(pcpu, pcluster);
63 }
64
65 static bool mcpm_cpu_can_disable(unsigned int cpu)
66 {
67 /* We assume all CPUs may be shut down. */
68 return true;
69 }
70
71 static void mcpm_cpu_die(unsigned int cpu)
72 {
73 unsigned int mpidr, pcpu, pcluster;
74 mpidr = read_cpuid_mpidr();
75 pcpu = MPIDR_AFFINITY_LEVEL(mpidr, 0);
76 pcluster = MPIDR_AFFINITY_LEVEL(mpidr, 1);
77 mcpm_set_entry_vector(pcpu, pcluster, NULL);
78 mcpm_cpu_power_down();
79 }
80
81 #endif
82
83 static const struct smp_operations mcpm_smp_ops __initconst = {
84 .smp_boot_secondary = mcpm_boot_secondary,
85 .smp_secondary_init = mcpm_secondary_init,
86 #ifdef CONFIG_HOTPLUG_CPU
87 .cpu_kill = mcpm_cpu_kill,
88 .cpu_can_disable = mcpm_cpu_can_disable,
89 .cpu_die = mcpm_cpu_die,
90 #endif
91 };
92
93 void __init mcpm_smp_set_ops(void)
94 {
95 smp_set_ops(&mcpm_smp_ops);
96 }
97
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