1// SPDX-License-Identifier: GPL-2.0 2/* 3 * Copyright (C) 2020 Western Digital Corporation or its affiliates. 4 */ 5 6#include <linux/kernel.h> 7#include <linux/mm.h> 8#include <linux/sched.h> 9#include <linux/err.h> 10#include <linux/irq.h> 11#include <linux/cpuhotplug.h> 12#include <linux/cpu.h> 13#include <linux/sched/hotplug.h> 14#include <asm/irq.h> 15#include <asm/cpu_ops.h> 16#include <asm/numa.h> 17#include <asm/smp.h> 18 19bool cpu_has_hotplug(unsigned int cpu) 20{ 21 if (cpu_ops->cpu_stop) 22 return true; 23 24 return false; 25} 26 27/* 28 * __cpu_disable runs on the processor to be shutdown. 29 */ 30int __cpu_disable(void) 31{ 32 unsigned int cpu = smp_processor_id(); 33 34 if (!cpu_ops->cpu_stop) 35 return -EOPNOTSUPP; 36 37 remove_cpu_topology(cpu); 38 numa_remove_cpu(cpu); 39 set_cpu_online(cpu, false); 40 riscv_ipi_disable(); 41 irq_migrate_all_off_this_cpu(); 42 43 return 0; 44} 45 46#ifdef CONFIG_HOTPLUG_CPU 47/* 48 * Called on the thread which is asking for a CPU to be shutdown, if the 49 * CPU reported dead to the hotplug core. 50 */ 51void arch_cpuhp_cleanup_dead_cpu(unsigned int cpu) 52{ 53 int ret = 0; 54 55 pr_notice("CPU%u: off\n", cpu); 56 57 /* Verify from the firmware if the cpu is really stopped*/ 58 if (cpu_ops->cpu_is_stopped) 59 ret = cpu_ops->cpu_is_stopped(cpu); 60 if (ret) 61 pr_warn("CPU%d may not have stopped: %d\n", cpu, ret); 62} 63 64/* 65 * Called from the idle thread for the CPU which has been shutdown. 66 */ 67void __noreturn arch_cpu_idle_dead(void) 68{ 69 idle_task_exit(); 70 71 cpuhp_ap_report_dead(); 72 73 cpu_ops->cpu_stop(); 74 /* It should never reach here */ 75 BUG(); 76} 77#endif 78