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