diff options
| -rw-r--r-- | arch/Kconfig | 4 | ||||
| -rw-r--r-- | include/linux/cpuhotplug.h | 4 | ||||
| -rw-r--r-- | kernel/cpu.c | 70 |
3 files changed, 76 insertions, 2 deletions
diff --git a/arch/Kconfig b/arch/Kconfig index f55c5fcbea38..d3015a61c148 100644 --- a/arch/Kconfig +++ b/arch/Kconfig @@ -49,6 +49,10 @@ config HOTPLUG_CORE_SYNC_FULL select HOTPLUG_CORE_SYNC_DEAD if HOTPLUG_CPU select HOTPLUG_CORE_SYNC +config HOTPLUG_SPLIT_STARTUP + bool + select HOTPLUG_CORE_SYNC_FULL + config GENERIC_ENTRY bool diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h index 5def71f81ec5..bc2d0a1d7608 100644 --- a/include/linux/cpuhotplug.h +++ b/include/linux/cpuhotplug.h @@ -133,6 +133,7 @@ enum cpuhp_state { CPUHP_MIPS_SOC_PREPARE, CPUHP_BP_PREPARE_DYN, CPUHP_BP_PREPARE_DYN_END = CPUHP_BP_PREPARE_DYN + 20, + CPUHP_BP_KICK_AP, CPUHP_BRINGUP_CPU, /* @@ -517,9 +518,12 @@ void cpuhp_online_idle(enum cpuhp_state state); static inline void cpuhp_online_idle(enum cpuhp_state state) { } #endif +struct task_struct; + void cpuhp_ap_sync_alive(void); void arch_cpuhp_sync_state_poll(void); void arch_cpuhp_cleanup_kick_cpu(unsigned int cpu); +int arch_cpuhp_kick_ap_alive(unsigned int cpu, struct task_struct *tidle); #ifdef CONFIG_HOTPLUG_CORE_SYNC_DEAD void cpuhp_ap_report_dead(void); diff --git a/kernel/cpu.c b/kernel/cpu.c index 0ab6a7d430c6..d2487aa4e7c8 100644 --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -761,6 +761,47 @@ static int bringup_wait_for_ap_online(unsigned int cpu) return 0; } +#ifdef CONFIG_HOTPLUG_SPLIT_STARTUP +static int cpuhp_kick_ap_alive(unsigned int cpu) +{ + if (!cpuhp_can_boot_ap(cpu)) + return -EAGAIN; + + return arch_cpuhp_kick_ap_alive(cpu, idle_thread_get(cpu)); +} + +static int cpuhp_bringup_ap(unsigned int cpu) +{ + struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); + int ret; + + /* + * Some architectures have to walk the irq descriptors to + * setup the vector space for the cpu which comes online. + * Prevent irq alloc/free across the bringup. + */ + irq_lock_sparse(); + + ret = cpuhp_bp_sync_alive(cpu); + if (ret) + goto out_unlock; + + ret = bringup_wait_for_ap_online(cpu); + if (ret) + goto out_unlock; + + irq_unlock_sparse(); + + if (st->target <= CPUHP_AP_ONLINE_IDLE) + return 0; + + return cpuhp_kick_ap(cpu, st, st->target); + +out_unlock: + irq_unlock_sparse(); + return ret; +} +#else static int bringup_cpu(unsigned int cpu) { struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); @@ -781,7 +822,6 @@ static int bringup_cpu(unsigned int cpu) */ irq_lock_sparse(); - /* Arch-specific enabling code. */ ret = __cpu_up(cpu, idle); if (ret) goto out_unlock; @@ -805,6 +845,7 @@ out_unlock: irq_unlock_sparse(); return ret; } +#endif static int finish_cpu(unsigned int cpu) { @@ -1944,13 +1985,38 @@ static struct cpuhp_step cpuhp_hp_states[] = { .startup.single = timers_prepare_cpu, .teardown.single = timers_dead_cpu, }, - /* Kicks the plugged cpu into life */ + +#ifdef CONFIG_HOTPLUG_SPLIT_STARTUP + /* + * Kicks the AP alive. AP will wait in cpuhp_ap_sync_alive() until + * the next step will release it. + */ + [CPUHP_BP_KICK_AP] = { + .name = "cpu:kick_ap", + .startup.single = cpuhp_kick_ap_alive, + }, + + /* + * Waits for the AP to reach cpuhp_ap_sync_alive() and then + * releases it for the complete bringup. + */ + [CPUHP_BRINGUP_CPU] = { + .name = "cpu:bringup", + .startup.single = cpuhp_bringup_ap, + .teardown.single = finish_cpu, + .cant_stop = true, + }, +#else + /* + * All-in-one CPU bringup state which includes the kick alive. + */ [CPUHP_BRINGUP_CPU] = { .name = "cpu:bringup", .startup.single = bringup_cpu, .teardown.single = finish_cpu, .cant_stop = true, }, +#endif /* Final state before CPU kills itself */ [CPUHP_AP_IDLE_DEAD] = { .name = "idle:dead", |