diff options
Diffstat (limited to 'kernel/cpu.c')
| -rw-r--r-- | kernel/cpu.c | 766 |
1 files changed, 644 insertions, 122 deletions
diff --git a/kernel/cpu.c b/kernel/cpu.c index e882c6babf4..a343bde710b 100644 --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -10,105 +10,296 @@ #include <linux/sched.h> #include <linux/unistd.h> #include <linux/cpu.h> -#include <linux/module.h> +#include <linux/oom.h> +#include <linux/rcupdate.h> +#include <linux/export.h> +#include <linux/bug.h> #include <linux/kthread.h> #include <linux/stop_machine.h> -#include <asm/semaphore.h> - -/* This protects CPUs going up and down... */ -static DECLARE_MUTEX(cpucontrol); +#include <linux/mutex.h> +#include <linux/gfp.h> +#include <linux/suspend.h> +#include <linux/lockdep.h> +#include <trace/events/power.h> + +#include "smpboot.h" + +#ifdef CONFIG_SMP +/* Serializes the updates to cpu_online_mask, cpu_present_mask */ +static DEFINE_MUTEX(cpu_add_remove_lock); + +/* + * The following two APIs (cpu_maps_update_begin/done) must be used when + * attempting to serialize the updates to cpu_online_mask & cpu_present_mask. + * The APIs cpu_notifier_register_begin/done() must be used to protect CPU + * hotplug callback (un)registration performed using __register_cpu_notifier() + * or __unregister_cpu_notifier(). + */ +void cpu_maps_update_begin(void) +{ + mutex_lock(&cpu_add_remove_lock); +} +EXPORT_SYMBOL(cpu_notifier_register_begin); -static struct notifier_block *cpu_chain; +void cpu_maps_update_done(void) +{ + mutex_unlock(&cpu_add_remove_lock); +} +EXPORT_SYMBOL(cpu_notifier_register_done); -#ifdef CONFIG_HOTPLUG_CPU -static struct task_struct *lock_cpu_hotplug_owner; -static int lock_cpu_hotplug_depth; +static RAW_NOTIFIER_HEAD(cpu_chain); -static int __lock_cpu_hotplug(int interruptible) -{ - int ret = 0; +/* If set, cpu_up and cpu_down will return -EBUSY and do nothing. + * Should always be manipulated under cpu_add_remove_lock + */ +static int cpu_hotplug_disabled; - if (lock_cpu_hotplug_owner != current) { - if (interruptible) - ret = down_interruptible(&cpucontrol); - else - down(&cpucontrol); - } +#ifdef CONFIG_HOTPLUG_CPU +static struct { + struct task_struct *active_writer; + struct mutex lock; /* Synchronizes accesses to refcount, */ /* - * Set only if we succeed in locking + * Also blocks the new readers during + * an ongoing cpu hotplug operation. */ - if (!ret) { - lock_cpu_hotplug_depth++; - lock_cpu_hotplug_owner = current; - } + int refcount; + +#ifdef CONFIG_DEBUG_LOCK_ALLOC + struct lockdep_map dep_map; +#endif +} cpu_hotplug = { + .active_writer = NULL, + .lock = __MUTEX_INITIALIZER(cpu_hotplug.lock), + .refcount = 0, +#ifdef CONFIG_DEBUG_LOCK_ALLOC + .dep_map = {.name = "cpu_hotplug.lock" }, +#endif +}; + +/* Lockdep annotations for get/put_online_cpus() and cpu_hotplug_begin/end() */ +#define cpuhp_lock_acquire_read() lock_map_acquire_read(&cpu_hotplug.dep_map) +#define cpuhp_lock_acquire() lock_map_acquire(&cpu_hotplug.dep_map) +#define cpuhp_lock_release() lock_map_release(&cpu_hotplug.dep_map) + +void get_online_cpus(void) +{ + might_sleep(); + if (cpu_hotplug.active_writer == current) + return; + cpuhp_lock_acquire_read(); + mutex_lock(&cpu_hotplug.lock); + cpu_hotplug.refcount++; + mutex_unlock(&cpu_hotplug.lock); - return ret; } +EXPORT_SYMBOL_GPL(get_online_cpus); -void lock_cpu_hotplug(void) +void put_online_cpus(void) { - __lock_cpu_hotplug(0); + if (cpu_hotplug.active_writer == current) + return; + mutex_lock(&cpu_hotplug.lock); + + if (WARN_ON(!cpu_hotplug.refcount)) + cpu_hotplug.refcount++; /* try to fix things up */ + + if (!--cpu_hotplug.refcount && unlikely(cpu_hotplug.active_writer)) + wake_up_process(cpu_hotplug.active_writer); + mutex_unlock(&cpu_hotplug.lock); + cpuhp_lock_release(); + } -EXPORT_SYMBOL_GPL(lock_cpu_hotplug); +EXPORT_SYMBOL_GPL(put_online_cpus); -void unlock_cpu_hotplug(void) +/* + * This ensures that the hotplug operation can begin only when the + * refcount goes to zero. + * + * Note that during a cpu-hotplug operation, the new readers, if any, + * will be blocked by the cpu_hotplug.lock + * + * Since cpu_hotplug_begin() is always called after invoking + * cpu_maps_update_begin(), we can be sure that only one writer is active. + * + * Note that theoretically, there is a possibility of a livelock: + * - Refcount goes to zero, last reader wakes up the sleeping + * writer. + * - Last reader unlocks the cpu_hotplug.lock. + * - A new reader arrives at this moment, bumps up the refcount. + * - The writer acquires the cpu_hotplug.lock finds the refcount + * non zero and goes to sleep again. + * + * However, this is very difficult to achieve in practice since + * get_online_cpus() not an api which is called all that often. + * + */ +void cpu_hotplug_begin(void) { - if (--lock_cpu_hotplug_depth == 0) { - lock_cpu_hotplug_owner = NULL; - up(&cpucontrol); + cpu_hotplug.active_writer = current; + + cpuhp_lock_acquire(); + for (;;) { + mutex_lock(&cpu_hotplug.lock); + if (likely(!cpu_hotplug.refcount)) + break; + __set_current_state(TASK_UNINTERRUPTIBLE); + mutex_unlock(&cpu_hotplug.lock); + schedule(); } } -EXPORT_SYMBOL_GPL(unlock_cpu_hotplug); -int lock_cpu_hotplug_interruptible(void) +void cpu_hotplug_done(void) +{ + cpu_hotplug.active_writer = NULL; + mutex_unlock(&cpu_hotplug.lock); + cpuhp_lock_release(); +} + +/* + * Wait for currently running CPU hotplug operations to complete (if any) and + * disable future CPU hotplug (from sysfs). The 'cpu_add_remove_lock' protects + * the 'cpu_hotplug_disabled' flag. The same lock is also acquired by the + * hotplug path before performing hotplug operations. So acquiring that lock + * guarantees mutual exclusion from any currently running hotplug operations. + */ +void cpu_hotplug_disable(void) +{ + cpu_maps_update_begin(); + cpu_hotplug_disabled = 1; + cpu_maps_update_done(); +} + +void cpu_hotplug_enable(void) { - return __lock_cpu_hotplug(1); + cpu_maps_update_begin(); + cpu_hotplug_disabled = 0; + cpu_maps_update_done(); } -EXPORT_SYMBOL_GPL(lock_cpu_hotplug_interruptible); + #endif /* CONFIG_HOTPLUG_CPU */ /* Need to know about CPUs going up/down? */ -int register_cpu_notifier(struct notifier_block *nb) +int __ref register_cpu_notifier(struct notifier_block *nb) { int ret; - - if ((ret = lock_cpu_hotplug_interruptible()) != 0) - return ret; - ret = notifier_chain_register(&cpu_chain, nb); - unlock_cpu_hotplug(); + cpu_maps_update_begin(); + ret = raw_notifier_chain_register(&cpu_chain, nb); + cpu_maps_update_done(); return ret; } + +int __ref __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, + int *nr_calls) +{ + int ret; + + ret = __raw_notifier_call_chain(&cpu_chain, val, v, nr_to_call, + nr_calls); + + return notifier_to_errno(ret); +} + +static int cpu_notify(unsigned long val, void *v) +{ + return __cpu_notify(val, v, -1, NULL); +} + +#ifdef CONFIG_HOTPLUG_CPU + +static void cpu_notify_nofail(unsigned long val, void *v) +{ + BUG_ON(cpu_notify(val, v)); +} EXPORT_SYMBOL(register_cpu_notifier); +EXPORT_SYMBOL(__register_cpu_notifier); -void unregister_cpu_notifier(struct notifier_block *nb) +void __ref unregister_cpu_notifier(struct notifier_block *nb) { - lock_cpu_hotplug(); - notifier_chain_unregister(&cpu_chain, nb); - unlock_cpu_hotplug(); + cpu_maps_update_begin(); + raw_notifier_chain_unregister(&cpu_chain, nb); + cpu_maps_update_done(); } EXPORT_SYMBOL(unregister_cpu_notifier); -#ifdef CONFIG_HOTPLUG_CPU +void __ref __unregister_cpu_notifier(struct notifier_block *nb) +{ + raw_notifier_chain_unregister(&cpu_chain, nb); +} +EXPORT_SYMBOL(__unregister_cpu_notifier); + +/** + * clear_tasks_mm_cpumask - Safely clear tasks' mm_cpumask for a CPU + * @cpu: a CPU id + * + * This function walks all processes, finds a valid mm struct for each one and + * then clears a corresponding bit in mm's cpumask. While this all sounds + * trivial, there are various non-obvious corner cases, which this function + * tries to solve in a safe manner. + * + * Also note that the function uses a somewhat relaxed locking scheme, so it may + * be called only for an already offlined CPU. + */ +void clear_tasks_mm_cpumask(int cpu) +{ + struct task_struct *p; + + /* + * This function is called after the cpu is taken down and marked + * offline, so its not like new tasks will ever get this cpu set in + * their mm mask. -- Peter Zijlstra + * Thus, we may use rcu_read_lock() here, instead of grabbing + * full-fledged tasklist_lock. + */ + WARN_ON(cpu_online(cpu)); + rcu_read_lock(); + for_each_process(p) { + struct task_struct *t; + + /* + * Main thread might exit, but other threads may still have + * a valid mm. Find one. + */ + t = find_lock_task_mm(p); + if (!t) + continue; + cpumask_clear_cpu(cpu, mm_cpumask(t->mm)); + task_unlock(t); + } + rcu_read_unlock(); +} + static inline void check_for_tasks(int cpu) { struct task_struct *p; + cputime_t utime, stime; write_lock_irq(&tasklist_lock); for_each_process(p) { - if (task_cpu(p) == cpu && - (!cputime_eq(p->utime, cputime_zero) || - !cputime_eq(p->stime, cputime_zero))) - printk(KERN_WARNING "Task %s (pid = %d) is on cpu %d\ - (state = %ld, flags = %lx) \n", - p->comm, p->pid, cpu, p->state, p->flags); + task_cputime(p, &utime, &stime); + if (task_cpu(p) == cpu && p->state == TASK_RUNNING && + (utime || stime)) + pr_warn("Task %s (pid = %d) is on cpu %d (state = %ld, flags = %x)\n", + p->comm, task_pid_nr(p), cpu, + p->state, p->flags); } write_unlock_irq(&tasklist_lock); } +struct take_cpu_down_param { + unsigned long mod; + void *hcpu; +}; + /* Take this CPU down. */ -static int take_cpu_down(void *unused) +static int __ref take_cpu_down(void *_param) { + struct take_cpu_down_param *param = _param; int err; /* Ensure this CPU doesn't handle any more interrupts. */ @@ -116,123 +307,454 @@ static int take_cpu_down(void *unused) if (err < 0) return err; - /* Force idle task to run as soon as we yield: it should - immediately notice cpu is offline and die quickly. */ - sched_idle_next(); + cpu_notify(CPU_DYING | param->mod, param->hcpu); + /* Park the stopper thread */ + kthread_park(current); return 0; } -int cpu_down(unsigned int cpu) +/* Requires cpu_add_remove_lock to be held */ +static int __ref _cpu_down(unsigned int cpu, int tasks_frozen) { - int err; - struct task_struct *p; - cpumask_t old_allowed, tmp; + int err, nr_calls = 0; + void *hcpu = (void *)(long)cpu; + unsigned long mod = tasks_frozen ? CPU_TASKS_FROZEN : 0; + struct take_cpu_down_param tcd_param = { + .mod = mod, + .hcpu = hcpu, + }; - if ((err = lock_cpu_hotplug_interruptible()) != 0) - return err; + if (num_online_cpus() == 1) + return -EBUSY; - if (num_online_cpus() == 1) { - err = -EBUSY; - goto out; - } + if (!cpu_online(cpu)) + return -EINVAL; - if (!cpu_online(cpu)) { - err = -EINVAL; - goto out; - } + cpu_hotplug_begin(); - err = notifier_call_chain(&cpu_chain, CPU_DOWN_PREPARE, - (void *)(long)cpu); - if (err == NOTIFY_BAD) { - printk("%s: attempt to take down CPU %u failed\n", - __FUNCTION__, cpu); - err = -EINVAL; - goto out; + err = __cpu_notify(CPU_DOWN_PREPARE | mod, hcpu, -1, &nr_calls); + if (err) { + nr_calls--; + __cpu_notify(CPU_DOWN_FAILED | mod, hcpu, nr_calls, NULL); + pr_warn("%s: attempt to take down CPU %u failed\n", + __func__, cpu); + goto out_release; } - /* Ensure that we are not runnable on dying cpu */ - old_allowed = current->cpus_allowed; - tmp = CPU_MASK_ALL; - cpu_clear(cpu, tmp); - set_cpus_allowed(current, tmp); + /* + * By now we've cleared cpu_active_mask, wait for all preempt-disabled + * and RCU users of this state to go away such that all new such users + * will observe it. + * + * For CONFIG_PREEMPT we have preemptible RCU and its sync_rcu() might + * not imply sync_sched(), so explicitly call both. + * + * Do sync before park smpboot threads to take care the rcu boost case. + */ +#ifdef CONFIG_PREEMPT + synchronize_sched(); +#endif + synchronize_rcu(); - p = __stop_machine_run(take_cpu_down, NULL, cpu); - if (IS_ERR(p)) { - /* CPU didn't die: tell everyone. Can't complain. */ - if (notifier_call_chain(&cpu_chain, CPU_DOWN_FAILED, - (void *)(long)cpu) == NOTIFY_BAD) - BUG(); + smpboot_park_threads(cpu); - err = PTR_ERR(p); - goto out_allowed; - } + /* + * So now all preempt/rcu users must observe !cpu_active(). + */ - if (cpu_online(cpu)) - goto out_thread; + err = __stop_machine(take_cpu_down, &tcd_param, cpumask_of(cpu)); + if (err) { + /* CPU didn't die: tell everyone. Can't complain. */ + smpboot_unpark_threads(cpu); + cpu_notify_nofail(CPU_DOWN_FAILED | mod, hcpu); + goto out_release; + } + BUG_ON(cpu_online(cpu)); - /* Wait for it to sleep (leaving idle task). */ + /* + * The migration_call() CPU_DYING callback will have removed all + * runnable tasks from the cpu, there's only the idle task left now + * that the migration thread is done doing the stop_machine thing. + * + * Wait for the stop thread to go away. + */ while (!idle_cpu(cpu)) - yield(); + cpu_relax(); /* This actually kills the CPU. */ __cpu_die(cpu); - /* Move it here so it can run. */ - kthread_bind(p, get_cpu()); - put_cpu(); - /* CPU is completely dead: tell everyone. Too late to complain. */ - if (notifier_call_chain(&cpu_chain, CPU_DEAD, (void *)(long)cpu) - == NOTIFY_BAD) - BUG(); + cpu_notify_nofail(CPU_DEAD | mod, hcpu); check_for_tasks(cpu); -out_thread: - err = kthread_stop(p); -out_allowed: - set_cpus_allowed(current, old_allowed); +out_release: + cpu_hotplug_done(); + if (!err) + cpu_notify_nofail(CPU_POST_DEAD | mod, hcpu); + return err; +} + +int __ref cpu_down(unsigned int cpu) +{ + int err; + + cpu_maps_update_begin(); + + if (cpu_hotplug_disabled) { + err = -EBUSY; + goto out; + } + + err = _cpu_down(cpu, 0); + out: - unlock_cpu_hotplug(); + cpu_maps_update_done(); return err; } +EXPORT_SYMBOL(cpu_down); #endif /*CONFIG_HOTPLUG_CPU*/ -int __devinit cpu_up(unsigned int cpu) +/* Requires cpu_add_remove_lock to be held */ +static int _cpu_up(unsigned int cpu, int tasks_frozen) { - int ret; + int ret, nr_calls = 0; void *hcpu = (void *)(long)cpu; + unsigned long mod = tasks_frozen ? CPU_TASKS_FROZEN : 0; + struct task_struct *idle; - if ((ret = lock_cpu_hotplug_interruptible()) != 0) - return ret; + cpu_hotplug_begin(); if (cpu_online(cpu) || !cpu_present(cpu)) { ret = -EINVAL; goto out; } - ret = notifier_call_chain(&cpu_chain, CPU_UP_PREPARE, hcpu); - if (ret == NOTIFY_BAD) { - printk("%s: attempt to bring up CPU %u failed\n", - __FUNCTION__, cpu); - ret = -EINVAL; + idle = idle_thread_get(cpu); + if (IS_ERR(idle)) { + ret = PTR_ERR(idle); + goto out; + } + + ret = smpboot_create_threads(cpu); + if (ret) + goto out; + + ret = __cpu_notify(CPU_UP_PREPARE | mod, hcpu, -1, &nr_calls); + if (ret) { + nr_calls--; + pr_warn("%s: attempt to bring up CPU %u failed\n", + __func__, cpu); goto out_notify; } /* Arch-specific enabling code. */ - ret = __cpu_up(cpu); + ret = __cpu_up(cpu, idle); if (ret != 0) goto out_notify; - if (!cpu_online(cpu)) - BUG(); + BUG_ON(!cpu_online(cpu)); + + /* Wake the per cpu threads */ + smpboot_unpark_threads(cpu); /* Now call notifier in preparation. */ - notifier_call_chain(&cpu_chain, CPU_ONLINE, hcpu); + cpu_notify(CPU_ONLINE | mod, hcpu); out_notify: if (ret != 0) - notifier_call_chain(&cpu_chain, CPU_UP_CANCELED, hcpu); + __cpu_notify(CPU_UP_CANCELED | mod, hcpu, nr_calls, NULL); out: - unlock_cpu_hotplug(); + cpu_hotplug_done(); + return ret; } + +int cpu_up(unsigned int cpu) +{ + int err = 0; + + if (!cpu_possible(cpu)) { + pr_err("can't online cpu %d because it is not configured as may-hotadd at boot time\n", + cpu); +#if defined(CONFIG_IA64) + pr_err("please check additional_cpus= boot parameter\n"); +#endif + return -EINVAL; + } + + err = try_online_node(cpu_to_node(cpu)); + if (err) + return err; + + cpu_maps_update_begin(); + + if (cpu_hotplug_disabled) { + err = -EBUSY; + goto out; + } + + err = _cpu_up(cpu, 0); + +out: + cpu_maps_update_done(); + return err; +} +EXPORT_SYMBOL_GPL(cpu_up); + +#ifdef CONFIG_PM_SLEEP_SMP +static cpumask_var_t frozen_cpus; + +int disable_nonboot_cpus(void) +{ + int cpu, first_cpu, error = 0; + + cpu_maps_update_begin(); + first_cpu = cpumask_first(cpu_online_mask); + /* + * We take down all of the non-boot CPUs in one shot to avoid races + * with the userspace trying to use the CPU hotplug at the same time + */ + cpumask_clear(frozen_cpus); + + pr_info("Disabling non-boot CPUs ...\n"); + for_each_online_cpu(cpu) { + if (cpu == first_cpu) + continue; + trace_suspend_resume(TPS("CPU_OFF"), cpu, true); + error = _cpu_down(cpu, 1); + trace_suspend_resume(TPS("CPU_OFF"), cpu, false); + if (!error) + cpumask_set_cpu(cpu, frozen_cpus); + else { + pr_err("Error taking CPU%d down: %d\n", cpu, error); + break; + } + } + + if (!error) { + BUG_ON(num_online_cpus() > 1); + /* Make sure the CPUs won't be enabled by someone else */ + cpu_hotplug_disabled = 1; + } else { + pr_err("Non-boot CPUs are not disabled\n"); + } + cpu_maps_update_done(); + return error; +} + +void __weak arch_enable_nonboot_cpus_begin(void) +{ +} + +void __weak arch_enable_nonboot_cpus_end(void) +{ +} + +void __ref enable_nonboot_cpus(void) +{ + int cpu, error; + + /* Allow everyone to use the CPU hotplug again */ + cpu_maps_update_begin(); + cpu_hotplug_disabled = 0; + if (cpumask_empty(frozen_cpus)) + goto out; + + pr_info("Enabling non-boot CPUs ...\n"); + + arch_enable_nonboot_cpus_begin(); + + for_each_cpu(cpu, frozen_cpus) { + trace_suspend_resume(TPS("CPU_ON"), cpu, true); + error = _cpu_up(cpu, 1); + trace_suspend_resume(TPS("CPU_ON"), cpu, false); + if (!error) { + pr_info("CPU%d is up\n", cpu); + continue; + } + pr_warn("Error taking CPU%d up: %d\n", cpu, error); + } + + arch_enable_nonboot_cpus_end(); + + cpumask_clear(frozen_cpus); +out: + cpu_maps_update_done(); +} + +static int __init alloc_frozen_cpus(void) +{ + if (!alloc_cpumask_var(&frozen_cpus, GFP_KERNEL|__GFP_ZERO)) + return -ENOMEM; + return 0; +} +core_initcall(alloc_frozen_cpus); + +/* + * When callbacks for CPU hotplug notifications are being executed, we must + * ensure that the state of the system with respect to the tasks being frozen + * or not, as reported by the notification, remains unchanged *throughout the + * duration* of the execution of the callbacks. + * Hence we need to prevent the freezer from racing with regular CPU hotplug. + * + * This synchronization is implemented by mutually excluding regular CPU + * hotplug and Suspend/Hibernate call paths by hooking onto the Suspend/ + * Hibernate notifications. + */ +static int +cpu_hotplug_pm_callback(struct notifier_block *nb, + unsigned long action, void *ptr) +{ + switch (action) { + + case PM_SUSPEND_PREPARE: + case PM_HIBERNATION_PREPARE: + cpu_hotplug_disable(); + break; + + case PM_POST_SUSPEND: + case PM_POST_HIBERNATION: + cpu_hotplug_enable(); + break; + + default: + return NOTIFY_DONE; + } + + return NOTIFY_OK; +} + + +static int __init cpu_hotplug_pm_sync_init(void) +{ + /* + * cpu_hotplug_pm_callback has higher priority than x86 + * bsp_pm_callback which depends on cpu_hotplug_pm_callback + * to disable cpu hotplug to avoid cpu hotplug race. + */ + pm_notifier(cpu_hotplug_pm_callback, 0); + return 0; +} +core_initcall(cpu_hotplug_pm_sync_init); + +#endif /* CONFIG_PM_SLEEP_SMP */ + +/** + * notify_cpu_starting(cpu) - call the CPU_STARTING notifiers + * @cpu: cpu that just started + * + * This function calls the cpu_chain notifiers with CPU_STARTING. + * It must be called by the arch code on the new cpu, before the new cpu + * enables interrupts and before the "boot" cpu returns from __cpu_up(). + */ +void notify_cpu_starting(unsigned int cpu) +{ + unsigned long val = CPU_STARTING; + +#ifdef CONFIG_PM_SLEEP_SMP + if (frozen_cpus != NULL && cpumask_test_cpu(cpu, frozen_cpus)) + val = CPU_STARTING_FROZEN; +#endif /* CONFIG_PM_SLEEP_SMP */ + cpu_notify(val, (void *)(long)cpu); +} + +#endif /* CONFIG_SMP */ + +/* + * cpu_bit_bitmap[] is a special, "compressed" data structure that + * represents all NR_CPUS bits binary values of 1<<nr. + * + * It is used by cpumask_of() to get a constant address to a CPU + * mask value that has a single bit set only. + */ + +/* cpu_bit_bitmap[0] is empty - so we can back into it */ +#define MASK_DECLARE_1(x) [x+1][0] = (1UL << (x)) +#define MASK_DECLARE_2(x) MASK_DECLARE_1(x), MASK_DECLARE_1(x+1) +#define MASK_DECLARE_4(x) MASK_DECLARE_2(x), MASK_DECLARE_2(x+2) +#define MASK_DECLARE_8(x) MASK_DECLARE_4(x), MASK_DECLARE_4(x+4) + +const unsigned long cpu_bit_bitmap[BITS_PER_LONG+1][BITS_TO_LONGS(NR_CPUS)] = { + + MASK_DECLARE_8(0), MASK_DECLARE_8(8), + MASK_DECLARE_8(16), MASK_DECLARE_8(24), +#if BITS_PER_LONG > 32 + MASK_DECLARE_8(32), MASK_DECLARE_8(40), + MASK_DECLARE_8(48), MASK_DECLARE_8(56), +#endif +}; +EXPORT_SYMBOL_GPL(cpu_bit_bitmap); + +const DECLARE_BITMAP(cpu_all_bits, NR_CPUS) = CPU_BITS_ALL; +EXPORT_SYMBOL(cpu_all_bits); + +#ifdef CONFIG_INIT_ALL_POSSIBLE +static DECLARE_BITMAP(cpu_possible_bits, CONFIG_NR_CPUS) __read_mostly + = CPU_BITS_ALL; +#else +static DECLARE_BITMAP(cpu_possible_bits, CONFIG_NR_CPUS) __read_mostly; +#endif +const struct cpumask *const cpu_possible_mask = to_cpumask(cpu_possible_bits); +EXPORT_SYMBOL(cpu_possible_mask); + +static DECLARE_BITMAP(cpu_online_bits, CONFIG_NR_CPUS) __read_mostly; +const struct cpumask *const cpu_online_mask = to_cpumask(cpu_online_bits); +EXPORT_SYMBOL(cpu_online_mask); + +static DECLARE_BITMAP(cpu_present_bits, CONFIG_NR_CPUS) __read_mostly; +const struct cpumask *const cpu_present_mask = to_cpumask(cpu_present_bits); +EXPORT_SYMBOL(cpu_present_mask); + +static DECLARE_BITMAP(cpu_active_bits, CONFIG_NR_CPUS) __read_mostly; +const struct cpumask *const cpu_active_mask = to_cpumask(cpu_active_bits); +EXPORT_SYMBOL(cpu_active_mask); + +void set_cpu_possible(unsigned int cpu, bool possible) +{ + if (possible) + cpumask_set_cpu(cpu, to_cpumask(cpu_possible_bits)); + else + cpumask_clear_cpu(cpu, to_cpumask(cpu_possible_bits)); +} + +void set_cpu_present(unsigned int cpu, bool present) +{ + if (present) + cpumask_set_cpu(cpu, to_cpumask(cpu_present_bits)); + else + cpumask_clear_cpu(cpu, to_cpumask(cpu_present_bits)); +} + +void set_cpu_online(unsigned int cpu, bool online) +{ + if (online) { + cpumask_set_cpu(cpu, to_cpumask(cpu_online_bits)); + cpumask_set_cpu(cpu, to_cpumask(cpu_active_bits)); + } else { + cpumask_clear_cpu(cpu, to_cpumask(cpu_online_bits)); + } +} + +void set_cpu_active(unsigned int cpu, bool active) +{ + if (active) + cpumask_set_cpu(cpu, to_cpumask(cpu_active_bits)); + else + cpumask_clear_cpu(cpu, to_cpumask(cpu_active_bits)); +} + +void init_cpu_present(const struct cpumask *src) +{ + cpumask_copy(to_cpumask(cpu_present_bits), src); +} + +void init_cpu_possible(const struct cpumask *src) +{ + cpumask_copy(to_cpumask(cpu_possible_bits), src); +} + +void init_cpu_online(const struct cpumask *src) +{ + cpumask_copy(to_cpumask(cpu_online_bits), src); +} |