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 
cpu_to_pcpu(unsigned int cpu,unsigned int * pcpu,unsigned int * pcluster)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 
mcpm_boot_secondary(unsigned int cpu,struct task_struct * idle)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 
mcpm_secondary_init(unsigned int cpu)49 static void mcpm_secondary_init(unsigned int cpu)
50 {
51 	mcpm_cpu_powered_up();
52 }
53 
54 #ifdef CONFIG_HOTPLUG_CPU
55 
mcpm_cpu_kill(unsigned int cpu)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 
mcpm_cpu_can_disable(unsigned int cpu)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 
mcpm_cpu_die(unsigned int cpu)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 
mcpm_smp_set_ops(void)93 void __init mcpm_smp_set_ops(void)
94 {
95 	smp_set_ops(&mcpm_smp_ops);
96 }
97