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- // 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();
- }
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