| 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 | |
| 19 | bool 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 | */ |
| 30 | int __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, online: 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 | */ |
| 51 | void 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 | */ |
| 67 | void __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 |