// SPDX-License-Identifier: GPL-2.0 /* * Copyright (C) 2020 Western Digital Corporation or its affiliates. */ #include <linux/kernel.h> #include <linux/mm.h> #include <linux/sched.h> #include <linux/err.h> #include <linux/irq.h> #include <linux/cpu.h> #include <linux/sched/hotplug.h> #include <asm/irq.h> #include <asm/cpu_ops.h> #include <asm/sbi.h> void cpu_stop(void); void arch_cpu_idle_dead(void) { cpu_stop(); } bool cpu_has_hotplug(unsigned int cpu) { if (cpu_ops[cpu]->cpu_stop) return true; return false; } /* * __cpu_disable runs on the processor to be shutdown. */ int __cpu_disable(void) { int ret = 0; unsigned int cpu = smp_processor_id(); if (!cpu_ops[cpu] || !cpu_ops[cpu]->cpu_stop) return -EOPNOTSUPP; if (cpu_ops[cpu]->cpu_disable) ret = cpu_ops[cpu]->cpu_disable(cpu); if (ret) return ret; remove_cpu_topology(cpu); set_cpu_online(cpu, false); irq_migrate_all_off_this_cpu(); return ret; } /* * Called on the thread which is asking for a CPU to be shutdown. */ void __cpu_die(unsigned int cpu) { int ret = 0; if (!cpu_wait_death(cpu, 5)) { pr_err("CPU %u: didn't die\n", cpu); return; } pr_notice("CPU%u: off\n", cpu); /* Verify from the firmware if the cpu is really stopped*/ if (cpu_ops[cpu]->cpu_is_stopped) ret = cpu_ops[cpu]->cpu_is_stopped(cpu); if (ret) pr_warn("CPU%d may not have stopped: %d\n", cpu, ret); } /* * Called from the idle thread for the CPU which has been shutdown. */ void cpu_stop(void) { idle_task_exit(); (void)cpu_report_death(); cpu_ops[smp_processor_id()]->cpu_stop(); /* It should never reach here */ BUG(); }