diff options
35 files changed, 1294 insertions, 236 deletions
diff --git a/arch/alpha/kernel/smp.c b/arch/alpha/kernel/smp.c index 2f24447fef92..46bf263c3153 100644 --- a/arch/alpha/kernel/smp.c +++ b/arch/alpha/kernel/smp.c @@ -168,7 +168,7 @@ smp_callin(void) cpuid, current, current->active_mm)); preempt_disable(); - cpu_startup_entry(CPUHP_ONLINE); + cpu_startup_entry(CPUHP_AP_ONLINE_IDLE); } /* Wait until hwrpb->txrdy is clear for cpu. Return -1 on timeout. */ diff --git a/arch/arc/kernel/smp.c b/arch/arc/kernel/smp.c index 424e937da5c8..4cb3add77c75 100644 --- a/arch/arc/kernel/smp.c +++ b/arch/arc/kernel/smp.c @@ -142,7 +142,7 @@ void start_kernel_secondary(void) local_irq_enable(); preempt_disable(); - cpu_startup_entry(CPUHP_ONLINE); + cpu_startup_entry(CPUHP_AP_ONLINE_IDLE); } /* diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c index 37312f6749f3..baee70267f29 100644 --- a/arch/arm/kernel/smp.c +++ b/arch/arm/kernel/smp.c @@ -409,7 +409,7 @@ asmlinkage void secondary_start_kernel(void) /* * OK, it's off to the idle thread for us */ - cpu_startup_entry(CPUHP_ONLINE); + cpu_startup_entry(CPUHP_AP_ONLINE_IDLE); } void __init smp_cpus_done(unsigned int max_cpus) diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c index b1adc51b2c2e..460765799c64 100644 --- a/arch/arm64/kernel/smp.c +++ b/arch/arm64/kernel/smp.c @@ -195,7 +195,7 @@ asmlinkage void secondary_start_kernel(void) /* * OK, it's off to the idle thread for us */ - cpu_startup_entry(CPUHP_ONLINE); + cpu_startup_entry(CPUHP_AP_ONLINE_IDLE); } #ifdef CONFIG_HOTPLUG_CPU diff --git a/arch/blackfin/mach-common/smp.c b/arch/blackfin/mach-common/smp.c index 0030e21cfceb..23c4ef5f8bdc 100644 --- a/arch/blackfin/mach-common/smp.c +++ b/arch/blackfin/mach-common/smp.c @@ -333,7 +333,7 @@ void secondary_start_kernel(void) /* We are done with local CPU inits, unblock the boot CPU. */ set_cpu_online(cpu, true); - cpu_startup_entry(CPUHP_ONLINE); + cpu_startup_entry(CPUHP_AP_ONLINE_IDLE); } void __init smp_prepare_boot_cpu(void) diff --git a/arch/hexagon/kernel/smp.c b/arch/hexagon/kernel/smp.c index ff759f26b96a..983bae7d2665 100644 --- a/arch/hexagon/kernel/smp.c +++ b/arch/hexagon/kernel/smp.c @@ -180,7 +180,7 @@ void start_secondary(void) local_irq_enable(); - cpu_startup_entry(CPUHP_ONLINE); + cpu_startup_entry(CPUHP_AP_ONLINE_IDLE); } diff --git a/arch/ia64/kernel/smpboot.c b/arch/ia64/kernel/smpboot.c index 0e76fad27975..74fe317477e6 100644 --- a/arch/ia64/kernel/smpboot.c +++ b/arch/ia64/kernel/smpboot.c @@ -454,7 +454,7 @@ start_secondary (void *unused) preempt_disable(); smp_callin(); - cpu_startup_entry(CPUHP_ONLINE); + cpu_startup_entry(CPUHP_AP_ONLINE_IDLE); return 0; } diff --git a/arch/m32r/kernel/smpboot.c b/arch/m32r/kernel/smpboot.c index a468467542f4..f98d2f6519d6 100644 --- a/arch/m32r/kernel/smpboot.c +++ b/arch/m32r/kernel/smpboot.c @@ -432,7 +432,7 @@ int __init start_secondary(void *unused) */ local_flush_tlb_all(); - cpu_startup_entry(CPUHP_ONLINE); + cpu_startup_entry(CPUHP_AP_ONLINE_IDLE); return 0; } diff --git a/arch/metag/kernel/smp.c b/arch/metag/kernel/smp.c index c3c6f0864881..bad13232de51 100644 --- a/arch/metag/kernel/smp.c +++ b/arch/metag/kernel/smp.c @@ -396,7 +396,7 @@ asmlinkage void secondary_start_kernel(void) /* * OK, it's off to the idle thread for us */ - cpu_startup_entry(CPUHP_ONLINE); + cpu_startup_entry(CPUHP_AP_ONLINE_IDLE); } void __init smp_cpus_done(unsigned int max_cpus) diff --git a/arch/mips/kernel/smp.c b/arch/mips/kernel/smp.c index 8b687fee0cb0..37708d9af638 100644 --- a/arch/mips/kernel/smp.c +++ b/arch/mips/kernel/smp.c @@ -328,7 +328,7 @@ asmlinkage void start_secondary(void) WARN_ON_ONCE(!irqs_disabled()); mp_ops->smp_finish(); - cpu_startup_entry(CPUHP_ONLINE); + cpu_startup_entry(CPUHP_AP_ONLINE_IDLE); } static void stop_this_cpu(void *dummy) diff --git a/arch/mn10300/kernel/smp.c b/arch/mn10300/kernel/smp.c index f984193718b1..426173c4b0b9 100644 --- a/arch/mn10300/kernel/smp.c +++ b/arch/mn10300/kernel/smp.c @@ -675,7 +675,7 @@ int __init start_secondary(void *unused) #ifdef CONFIG_GENERIC_CLOCKEVENTS init_clockevents(); #endif - cpu_startup_entry(CPUHP_ONLINE); + cpu_startup_entry(CPUHP_AP_ONLINE_IDLE); return 0; } diff --git a/arch/parisc/kernel/smp.c b/arch/parisc/kernel/smp.c index 52e85973a283..c2a9cc55a62f 100644 --- a/arch/parisc/kernel/smp.c +++ b/arch/parisc/kernel/smp.c @@ -305,7 +305,7 @@ void __init smp_callin(void) local_irq_enable(); /* Interrupts have been off until now */ - cpu_startup_entry(CPUHP_ONLINE); + cpu_startup_entry(CPUHP_AP_ONLINE_IDLE); /* NOTREACHED */ panic("smp_callin() AAAAaaaaahhhh....\n"); diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c index ec9ec2058d2d..cc13d4c83291 100644 --- a/arch/powerpc/kernel/smp.c +++ b/arch/powerpc/kernel/smp.c @@ -727,7 +727,7 @@ void start_secondary(void *unused) local_irq_enable(); - cpu_startup_entry(CPUHP_ONLINE); + cpu_startup_entry(CPUHP_AP_ONLINE_IDLE); BUG(); } diff --git a/arch/s390/kernel/smp.c b/arch/s390/kernel/smp.c index 3c65a8eae34d..40a6b4f9c36c 100644 --- a/arch/s390/kernel/smp.c +++ b/arch/s390/kernel/smp.c @@ -798,7 +798,7 @@ static void smp_start_secondary(void *cpuvoid) set_cpu_online(smp_processor_id(), true); inc_irq_stat(CPU_RST); local_irq_enable(); - cpu_startup_entry(CPUHP_ONLINE); + cpu_startup_entry(CPUHP_AP_ONLINE_IDLE); } /* Upping and downing of CPUs */ diff --git a/arch/sh/kernel/smp.c b/arch/sh/kernel/smp.c index de6be008fc01..13f633add29a 100644 --- a/arch/sh/kernel/smp.c +++ b/arch/sh/kernel/smp.c @@ -203,7 +203,7 @@ asmlinkage void start_secondary(void) set_cpu_online(cpu, true); per_cpu(cpu_state, cpu) = CPU_ONLINE; - cpu_startup_entry(CPUHP_ONLINE); + cpu_startup_entry(CPUHP_AP_ONLINE_IDLE); } extern struct { diff --git a/arch/sparc/kernel/smp_32.c b/arch/sparc/kernel/smp_32.c index b3a5d81b20f0..fb30e7c6a5b1 100644 --- a/arch/sparc/kernel/smp_32.c +++ b/arch/sparc/kernel/smp_32.c @@ -364,7 +364,7 @@ static void sparc_start_secondary(void *arg) local_irq_enable(); wmb(); - cpu_startup_entry(CPUHP_ONLINE); + cpu_startup_entry(CPUHP_AP_ONLINE_IDLE); /* We should never reach here! */ BUG(); diff --git a/arch/sparc/kernel/smp_64.c b/arch/sparc/kernel/smp_64.c index 19cd08d18672..8a6151a628ce 100644 --- a/arch/sparc/kernel/smp_64.c +++ b/arch/sparc/kernel/smp_64.c @@ -134,7 +134,7 @@ void smp_callin(void) local_irq_enable(); - cpu_startup_entry(CPUHP_ONLINE); + cpu_startup_entry(CPUHP_AP_ONLINE_IDLE); } void cpu_panic(void) diff --git a/arch/tile/kernel/smpboot.c b/arch/tile/kernel/smpboot.c index 20d52a98e171..6c0abaacec33 100644 --- a/arch/tile/kernel/smpboot.c +++ b/arch/tile/kernel/smpboot.c @@ -208,7 +208,7 @@ void online_secondary(void) /* Set up tile-timer clock-event device on this cpu */ setup_tile_timer(); - cpu_startup_entry(CPUHP_ONLINE); + cpu_startup_entry(CPUHP_AP_ONLINE_IDLE); } int __cpu_up(unsigned int cpu, struct task_struct *tidle) diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c index 3bf1e0b5f827..643dbdccf4bc 100644 --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -256,7 +256,7 @@ static void notrace start_secondary(void *unused) x86_cpuinit.setup_percpu_clockev(); wmb(); - cpu_startup_entry(CPUHP_ONLINE); + cpu_startup_entry(CPUHP_AP_ONLINE_IDLE); } int topology_update_package_map(unsigned int apicid, unsigned int cpu) diff --git a/arch/x86/xen/smp.c b/arch/x86/xen/smp.c index 3f4ebf0261f2..3c6d17fd423a 100644 --- a/arch/x86/xen/smp.c +++ b/arch/x86/xen/smp.c @@ -112,7 +112,7 @@ asmlinkage __visible void cpu_bringup_and_idle(int cpu) xen_pvh_secondary_vcpu_init(cpu); #endif cpu_bringup(); - cpu_startup_entry(CPUHP_ONLINE); + cpu_startup_entry(CPUHP_AP_ONLINE_IDLE); } static void xen_smp_intr_free(unsigned int cpu) diff --git a/arch/xtensa/kernel/smp.c b/arch/xtensa/kernel/smp.c index 4d02e38514f5..fc4ad21a5ed4 100644 --- a/arch/xtensa/kernel/smp.c +++ b/arch/xtensa/kernel/smp.c @@ -157,7 +157,7 @@ void secondary_start_kernel(void) complete(&cpu_running); - cpu_startup_entry(CPUHP_ONLINE); + cpu_startup_entry(CPUHP_AP_ONLINE_IDLE); } static void mx_cpu_start(void *p) diff --git a/include/linux/cpu.h b/include/linux/cpu.h index d2ca8c38f9c4..f9b1fab4388a 100644 --- a/include/linux/cpu.h +++ b/include/linux/cpu.h @@ -16,6 +16,7 @@ #include <linux/node.h> #include <linux/compiler.h> #include <linux/cpumask.h> +#include <linux/cpuhotplug.h> struct device; struct device_node; @@ -27,6 +28,9 @@ struct cpu { struct device dev; }; +extern void boot_cpu_init(void); +extern void boot_cpu_state_init(void); + extern int register_cpu(struct cpu *cpu, int num); extern struct device *get_cpu_device(unsigned cpu); extern bool cpu_is_hotpluggable(unsigned cpu); @@ -74,7 +78,7 @@ enum { /* migration should happen before other stuff but after perf */ CPU_PRI_PERF = 20, CPU_PRI_MIGRATION = 10, - CPU_PRI_SMPBOOT = 9, + /* bring up workqueues before normal notifiers and down after */ CPU_PRI_WORKQUEUE_UP = 5, CPU_PRI_WORKQUEUE_DOWN = -5, @@ -97,9 +101,7 @@ enum { * Called on the new cpu, just before * enabling interrupts. Must not sleep, * must not fail */ -#define CPU_DYING_IDLE 0x000B /* CPU (unsigned)v dying, reached - * idle loop. */ -#define CPU_BROKEN 0x000C /* CPU (unsigned)v did not die properly, +#define CPU_BROKEN 0x000B /* CPU (unsigned)v did not die properly, * perhaps due to preemption. */ /* Used for CPU hotplug events occurring while tasks are frozen due to a suspend @@ -118,6 +120,7 @@ enum { #ifdef CONFIG_SMP +extern bool cpuhp_tasks_frozen; /* Need to know about CPUs going up/down? */ #if defined(CONFIG_HOTPLUG_CPU) || !defined(MODULE) #define cpu_notifier(fn, pri) { \ @@ -167,7 +170,6 @@ static inline void __unregister_cpu_notifier(struct notifier_block *nb) } #endif -void smpboot_thread_init(void); int cpu_up(unsigned int cpu); void notify_cpu_starting(unsigned int cpu); extern void cpu_maps_update_begin(void); @@ -177,6 +179,7 @@ extern void cpu_maps_update_done(void); #define cpu_notifier_register_done cpu_maps_update_done #else /* CONFIG_SMP */ +#define cpuhp_tasks_frozen 0 #define cpu_notifier(fn, pri) do { (void)(fn); } while (0) #define __cpu_notifier(fn, pri) do { (void)(fn); } while (0) @@ -215,10 +218,6 @@ static inline void cpu_notifier_register_done(void) { } -static inline void smpboot_thread_init(void) -{ -} - #endif /* CONFIG_SMP */ extern struct bus_type cpu_subsys; @@ -265,11 +264,6 @@ static inline int disable_nonboot_cpus(void) { return 0; } static inline void enable_nonboot_cpus(void) {} #endif /* !CONFIG_PM_SLEEP_SMP */ -enum cpuhp_state { - CPUHP_OFFLINE, - CPUHP_ONLINE, -}; - void cpu_startup_entry(enum cpuhp_state state); void cpu_idle_poll_ctrl(bool enable); @@ -280,14 +274,15 @@ void arch_cpu_idle_enter(void); void arch_cpu_idle_exit(void); void arch_cpu_idle_dead(void); -DECLARE_PER_CPU(bool, cpu_dead_idle); - int cpu_report_state(int cpu); int cpu_check_up_prepare(int cpu); void cpu_set_state_online(int cpu); #ifdef CONFIG_HOTPLUG_CPU bool cpu_wait_death(unsigned int cpu, int seconds); bool cpu_report_death(void); +void cpuhp_report_idle_dead(void); +#else +static inline void cpuhp_report_idle_dead(void) { } #endif /* #ifdef CONFIG_HOTPLUG_CPU */ #endif /* _LINUX_CPU_H_ */ diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h new file mode 100644 index 000000000000..5d68e15e46b7 --- /dev/null +++ b/include/linux/cpuhotplug.h @@ -0,0 +1,93 @@ +#ifndef __CPUHOTPLUG_H +#define __CPUHOTPLUG_H + +enum cpuhp_state { + CPUHP_OFFLINE, + CPUHP_CREATE_THREADS, + CPUHP_NOTIFY_PREPARE, + CPUHP_BRINGUP_CPU, + CPUHP_AP_IDLE_DEAD, + CPUHP_AP_OFFLINE, + CPUHP_AP_NOTIFY_STARTING, + CPUHP_AP_ONLINE, + CPUHP_TEARDOWN_CPU, + CPUHP_AP_ONLINE_IDLE, + CPUHP_AP_SMPBOOT_THREADS, + CPUHP_AP_NOTIFY_ONLINE, + CPUHP_AP_ONLINE_DYN, + CPUHP_AP_ONLINE_DYN_END = CPUHP_AP_ONLINE_DYN + 30, + CPUHP_ONLINE, +}; + +int __cpuhp_setup_state(enum cpuhp_state state, const char *name, bool invoke, + int (*startup)(unsigned int cpu), + int (*teardown)(unsigned int cpu)); + +/** + * cpuhp_setup_state - Setup hotplug state callbacks with calling the callbacks + * @state: The state for which the calls are installed + * @name: Name of the callback (will be used in debug output) + * @startup: startup callback function + * @teardown: teardown callback function + * + * Installs the callback functions and invokes the startup callback on + * the present cpus which have already reached the @state. + */ +static inline int cpuhp_setup_state(enum cpuhp_state state, + const char *name, + int (*startup)(unsigned int cpu), + int (*teardown)(unsigned int cpu)) +{ + return __cpuhp_setup_state(state, name, true, startup, teardown); +} + +/** + * cpuhp_setup_state_nocalls - Setup hotplug state callbacks without calling the + * callbacks + * @state: The state for which the calls are installed + * @name: Name of the callback. + * @startup: startup callback function + * @teardown: teardown callback function + * + * Same as @cpuhp_setup_state except that no calls are executed are invoked + * during installation of this callback. NOP if SMP=n or HOTPLUG_CPU=n. + */ +static inline int cpuhp_setup_state_nocalls(enum cpuhp_state state, + const char *name, + int (*startup)(unsigned int cpu), + int (*teardown)(unsigned int cpu)) +{ + return __cpuhp_setup_state(state, name, false, startup, teardown); +} + +void __cpuhp_remove_state(enum cpuhp_state state, bool invoke); + +/** + * cpuhp_remove_state - Remove hotplug state callbacks and invoke the teardown + * @state: The state for which the calls are removed + * + * Removes the callback functions and invokes the teardown callback on + * the present cpus which have already reached the @state. + */ +static inline void cpuhp_remove_state(enum cpuhp_state state) +{ + __cpuhp_remove_state(state, true); +} + +/** + * cpuhp_remove_state_nocalls - Remove hotplug state callbacks without invoking + * teardown + * @state: The state for which the calls are removed + */ +static inline void cpuhp_remove_state_nocalls(enum cpuhp_state state) +{ + __cpuhp_remove_state(state, false); +} + +#ifdef CONFIG_SMP +void cpuhp_online_idle(enum cpuhp_state state); +#else +static inline void cpuhp_online_idle(enum cpuhp_state state) { } +#endif + +#endif diff --git a/include/linux/notifier.h b/include/linux/notifier.h index d14a4c362465..4149868de4e6 100644 --- a/include/linux/notifier.h +++ b/include/linux/notifier.h @@ -47,6 +47,8 @@ * runtime initialization. */ +struct notifier_block; + typedef int (*notifier_fn_t)(struct notifier_block *nb, unsigned long action, void *data); diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h index b5d48bd56e3f..2657aff2725b 100644 --- a/include/linux/rcupdate.h +++ b/include/linux/rcupdate.h @@ -332,9 +332,7 @@ void rcu_init(void); void rcu_sched_qs(void); void rcu_bh_qs(void); void rcu_check_callbacks(int user); -struct notifier_block; -int rcu_cpu_notify(struct notifier_block *self, - unsigned long action, void *hcpu); +void rcu_report_dead(unsigned int cpu); #ifndef CONFIG_TINY_RCU void rcu_end_inkernel_boot(void); diff --git a/include/trace/events/cpuhp.h b/include/trace/events/cpuhp.h new file mode 100644 index 000000000000..a72bd93ec7e5 --- /dev/null +++ b/include/trace/events/cpuhp.h @@ -0,0 +1,66 @@ +#undef TRACE_SYSTEM +#define TRACE_SYSTEM cpuhp + +#if !defined(_TRACE_CPUHP_H) || defined(TRACE_HEADER_MULTI_READ) +#define _TRACE_CPUHP_H + +#include <linux/tracepoint.h> + +TRACE_EVENT(cpuhp_enter, + + TP_PROTO(unsigned int cpu, + int target, + int idx, + int (*fun)(unsigned int)), + + TP_ARGS(cpu, target, idx, fun), + + TP_STRUCT__entry( + __field( unsigned int, cpu ) + __field( int, target ) + __field( int, idx ) + __field( void *, fun ) + ), + + TP_fast_assign( + __entry->cpu = cpu; + __entry->target = target; + __entry->idx = idx; + __entry->fun = fun; + ), + + TP_printk("cpu: %04u target: %3d step: %3d (%pf)", + __entry->cpu, __entry->target, __entry->idx, __entry->fun) +); + +TRACE_EVENT(cpuhp_exit, + + TP_PROTO(unsigned int cpu, + int state, + int idx, + int ret), + + TP_ARGS(cpu, state, idx, ret), + + TP_STRUCT__entry( + __field( unsigned int, cpu ) + __field( int, state ) + __field( int, idx ) + __field( int, ret ) + ), + + TP_fast_assign( + __entry->cpu = cpu; + __entry->state = state; + __entry->idx = idx; + __entry->ret = ret; + ), + + TP_printk(" cpu: %04u state: %3d step: %3d ret: %d", + __entry->cpu, __entry->state, __entry->idx, __entry->ret) +); + +#endif + +/* This part must be outside protection */ +#include <trace/define_trace.h> diff --git a/init/main.c b/init/main.c index 7c27de4577ed..8dc93df20f7f 100644 --- a/init/main.c +++ b/init/main.c @@ -385,7 +385,6 @@ static noinline void __init_refok rest_init(void) int pid; rcu_scheduler_starting(); - smpboot_thread_init(); /* * We need to spawn init first so that it obtains pid 1, however * the init task will end up wanting to create kthreads, which, if @@ -449,20 +448,6 @@ void __init parse_early_param(void) done = 1; } -/* - * Activate the first processor. - */ - -static void __init boot_cpu_init(void) -{ - int cpu = smp_processor_id(); - /* Mark the boot cpu "present", "online" etc for SMP and UP case */ - set_cpu_online(cpu, true); - set_cpu_active(cpu, true); - set_cpu_present(cpu, true); - set_cpu_possible(cpu, true); -} - void __init __weak smp_setup_processor_id(void) { } @@ -522,6 +507,7 @@ asmlinkage __visible void __init start_kernel(void) setup_command_line(command_line); setup_nr_cpu_ids(); setup_per_cpu_areas(); + boot_cpu_state_init(); smp_prepare_boot_cpu(); /* arch-specific boot-cpu hooks */ build_all_zonelists(NULL, NULL); diff --git a/kernel/cpu.c b/kernel/cpu.c index 5b9d39633ce9..6ea42e8da861 100644 --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -22,13 +22,88 @@ #include <linux/lockdep.h> #include <linux/tick.h> #include <linux/irq.h> +#include <linux/smpboot.h> + #include <trace/events/power.h> +#define CREATE_TRACE_POINTS +#include <trace/events/cpuhp.h> #include "smpboot.h" +/** + * cpuhp_cpu_state - Per cpu hotplug state storage + * @state: The current cpu state + * @target: The target state + * @thread: Pointer to the hotplug thread + * @should_run: Thread should execute + * @cb_stat: The state for a single callback (install/uninstall) + * @cb: Single callback function (install/uninstall) + * @result: Result of the operation + * @done: Signal completion to the issuer of the task + */ +struct cpuhp_cpu_state { + enum cpuhp_state state; + enum cpuhp_state target; +#ifdef CONFIG_SMP + struct task_struct *thread; + bool should_run; + enum cpuhp_state cb_state; + int (*cb)(unsigned int cpu); + int result; + struct completion done; +#endif +}; + +static DEFINE_PER_CPU(struct cpuhp_cpu_state, cpuhp_state); + +/** + * cpuhp_step - Hotplug state machine step + * @name: Name of the step + * @startup: Startup function of the step + * @teardown: Teardown function of the step + * @skip_onerr: Do not invoke the functions on error rollback + * Will go away once the notifiers are gone + * @cant_stop: Bringup/teardown can't be stopped at this step + */ +struct cpuhp_step { + const char *name; + int (*startup)(unsigned int cpu); + int (*teardown)(unsigned int cpu); + bool skip_onerr; + bool cant_stop; +}; + +static DEFINE_MUTEX(cpuhp_state_mutex); +static struct cpuhp_step cpuhp_bp_states[]; +static struct cpuhp_step cpuhp_ap_states[]; + +/** + * cpuhp_invoke_callback _ Invoke the callbacks for a given state + * @cpu: The cpu for which the callback should be invoked + * @step: The step in the state machine + * @cb: The callback function to invoke + * + * Called from cpu hotplug and from the state register machinery + */ +static int cpuhp_invoke_callback(unsigned int cpu, enum cpuhp_state step, + int (*cb)(unsigned int)) +{ + struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); + int ret = 0; + + if (cb) { + trace_cpuhp_enter(cpu, st->target, step, cb); + ret = cb(cpu); + trace_cpuhp_exit(cpu, st->state, step, ret); + } + return ret; +} + #ifdef CONFIG_SMP /* Serializes the updates to cpu_online_mask, cpu_present_mask */ static DEFINE_MUTEX(cpu_add_remove_lock); +bool cpuhp_tasks_frozen; +EXPORT_SYMBOL_GPL(cpuhp_tasks_frozen); /* * The following two APIs (cpu_maps_update_begin/done) must be used when @@ -207,31 +282,281 @@ int __register_cpu_notifier(struct notifier_block *nb) return raw_notifier_chain_register(&cpu_chain, nb); } -static int __cpu_notify(unsigned long val, void *v, int nr_to_call, +static int __cpu_notify(unsigned long val, unsigned int cpu, int nr_to_call, int *nr_calls) { + unsigned long mod = cpuhp_tasks_frozen ? CPU_TASKS_FROZEN : 0; + void *hcpu = (void *)(long)cpu; + int ret; - ret = __raw_notifier_call_chain(&cpu_chain, val, v, nr_to_call, + ret = __raw_notifier_call_chain(&cpu_chain, val | mod, hcpu, nr_to_call, nr_calls); return notifier_to_errno(ret); } -static int cpu_notify(unsigned long val, void *v) +static int cpu_notify(unsigned long val, unsigned int cpu) { - return __cpu_notify(val, v, -1, NULL); + return __cpu_notify(val, cpu, -1, NULL); } -#ifdef CONFIG_HOTPLUG_CPU +/* Notifier wrappers for transitioning to state machine */ +static int notify_prepare(unsigned int cpu) +{ + int nr_calls = 0; + int ret; + + ret = __cpu_notify(CPU_UP_PREPARE, cpu, -1, &nr_calls); + if (ret) { + nr_calls--; + printk(KERN_WARNING "%s: attempt to bring up CPU %u failed\n", + __func__, cpu); + __cpu_notify(CPU_UP_CANCELED, cpu, nr_calls, NULL); + } + return ret; +} + +static int notify_online(unsigned int cpu) +{ + cpu_notify(CPU_ONLINE, cpu); + return 0; +} + +static int notify_starting(unsigned int cpu) +{ + cpu_notify(CPU_STARTING, cpu); + return 0; +} + +static int bringup_wait_for_ap(unsigned int cpu) +{ + struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); + + wait_for_completion(&st->done); + return st->result; +} + +static int bringup_cpu(unsigned int cpu) +{ + struct task_struct *idle = idle_thread_get(cpu); + int ret; + + /* Arch-specific enabling code. */ + ret = __cpu_up(cpu, idle); + if (ret) { + cpu_notify(CPU_UP_CANCELED, cpu); + return ret; + } + ret = bringup_wait_for_ap(cpu); + BUG_ON(!cpu_online(cpu)); + return ret; +} + +/* + * Hotplug state machine related functions + */ +static void undo_cpu_down(unsigned int cpu, struct cpuhp_cpu_state *st, + struct cpuhp_step *steps) +{ + for (st->state++; st->state < st->target; st->state++) { + struct cpuhp_step *step = steps + st->state; + + if (!step->skip_onerr) + cpuhp_invoke_callback(cpu, st->state, step->startup); + } +} + +static int cpuhp_down_callbacks(unsigned int cpu, struct cpuhp_cpu_state *st, + struct cpuhp_step *steps, enum cpuhp_state target) +{ + enum cpuhp_state prev_state = st->state; + int ret = 0; + + for (; st->state > target; st->state--) { + struct cpuhp_step *step = steps + st->state; + + ret = cpuhp_invoke_callback(cpu, st->state, step->teardown); + if (ret) { + st->target = prev_state; + undo_cpu_down(cpu, st, steps); + break; + } + } + return ret; +} + +static void undo_cpu_up(unsigned int cpu, struct cpuhp_cpu_state *st, + struct cpuhp_step *steps) +{ + for (st->state--; st->state > st->target; st->state--) { + struct cpuhp_step *step = steps + st->state; + + if (!step->skip_onerr) + cpuhp_invoke_callback(cpu, st->state, step->teardown); + } +} + +static int cpuhp_up_callbacks(unsigned int cpu, struct cpuhp_cpu_state *st, + struct cpuhp_step *steps, enum cpuhp_state target) +{ + enum cpuhp_state prev_state = st->state; + int ret = 0; + + while (st->state < target) { + struct cpuhp_step *step; + + st->state++; + step = steps + st->state; + ret = cpuhp_invoke_callback(cpu, st->state, step->startup); + if (ret) { + st->target = prev_state; + undo_cpu_up(cpu, st, steps); + break; + } + } + return ret; +} + +/* + * The cpu hotplug threads manage the bringup and teardown of the cpus + */ +static void cpuhp_create(unsigned int cpu) +{ |