diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h index 09c6583ba133..70cc1717299b 100644 --- a/include/linux/interrupt.h +++ b/include/linux/interrupt.h @@ -241,7 +241,7 @@ extern int irq_set_affinity_hint(unsigned int irq, const struct cpumask *m); * struct irq_affinity_notify - context for notification of IRQ affinity changes * @irq: Interrupt to which notification applies * @kref: Reference count, for internal use - * @work: Work item, for internal use + * @list: Add to the notifier list, for internal use * @notify: Function to be called on change. This will be * called in process context. * @release: Function to be called on release. This will be @@ -252,7 +252,7 @@ extern int irq_set_affinity_hint(unsigned int irq, const struct cpumask *m); struct irq_affinity_notify { unsigned int irq; struct kref kref; - struct work_struct work; + struct list_head list; void (*notify)(struct irq_affinity_notify *, const cpumask_t *mask); void (*release)(struct kref *ref); }; @@ -260,6 +260,8 @@ struct irq_affinity_notify { extern int irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify); +extern int +irq_release_affinity_notifier(struct irq_affinity_notify *notify); #else /* CONFIG_SMP */ static inline int irq_set_affinity(unsigned int irq, const struct cpumask *m) diff --git a/include/linux/irqdesc.h b/include/linux/irqdesc.h index 472c021a2d4f..db3509ea165b 100644 --- a/include/linux/irqdesc.h +++ b/include/linux/irqdesc.h @@ -31,7 +31,8 @@ struct irq_desc; * @threads_handled_last: comparator field for deferred spurious detection of theraded handlers * @lock: locking for SMP * @affinity_hint: hint to user space for preferred irq affinity - * @affinity_notify: context for notification of affinity changes + * @affinity_notify: list of notification clients for affinity changes + * @affinity_work: Work queue for handling affinity change notifications * @pending_mask: pending rebalanced interrupts * @threads_oneshot: bitfield to handle shared oneshot threads * @threads_active: number of irqaction threads currently running @@ -60,7 +61,8 @@ struct irq_desc { struct cpumask *percpu_enabled; #ifdef CONFIG_SMP const struct cpumask *affinity_hint; - struct irq_affinity_notify *affinity_notify; + struct list_head affinity_notify; + struct work_struct affinity_work; #ifdef CONFIG_GENERIC_PENDING_IRQ cpumask_var_t pending_mask; #endif diff --git a/kernel/irq/irqdesc.c b/kernel/irq/irqdesc.c index 8ab8e9390297..157184cd19e5 100644 --- a/kernel/irq/irqdesc.c +++ b/kernel/irq/irqdesc.c @@ -91,6 +91,9 @@ static void desc_set_defaults(unsigned int irq, struct irq_desc *desc, int node, for_each_possible_cpu(cpu) *per_cpu_ptr(desc->kstat_irqs, cpu) = 0; desc_smp_init(desc, node); +#ifdef CONFIG_SMP + INIT_LIST_HEAD(&desc->affinity_notify); +#endif } int nr_irqs = NR_IRQS; diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c index 053ef8447516..cbaf5a61311f 100644 --- a/kernel/irq/manage.c +++ b/kernel/irq/manage.c @@ -179,10 +179,9 @@ int irq_set_affinity_locked(struct irq_data *data, const struct cpumask *mask, irq_copy_pending(desc, mask); } - if (desc->affinity_notify) { - kref_get(&desc->affinity_notify->kref); - schedule_work(&desc->affinity_notify->work); - } + if (!list_empty(&desc->affinity_notify)) + schedule_work(&desc->affinity_work); + irqd_set(data, IRQD_AFFINITY_SET); return ret; @@ -219,14 +218,14 @@ EXPORT_SYMBOL_GPL(irq_set_affinity_hint); static void irq_affinity_notify(struct work_struct *work) { - struct irq_affinity_notify *notify = - container_of(work, struct irq_affinity_notify, work); - struct irq_desc *desc = irq_to_desc(notify->irq); + struct irq_desc *desc = + container_of(work, struct irq_desc, affinity_work); cpumask_var_t cpumask; unsigned long flags; + struct irq_affinity_notify *notify; if (!desc || !alloc_cpumask_var(&cpumask, GFP_KERNEL)) - goto out; + return; raw_spin_lock_irqsave(&desc->lock, flags); if (irq_move_pending(&desc->irq_data)) @@ -235,11 +234,20 @@ static void irq_affinity_notify(struct work_struct *work) cpumask_copy(cpumask, desc->irq_data.affinity); raw_spin_unlock_irqrestore(&desc->lock, flags); - notify->notify(notify, cpumask); + list_for_each_entry(notify, &desc->affinity_notify, list) { + /** + * Check and get the kref only if the kref has not been + * released by now. Its possible that the reference count + * is already 0, we dont want to notify those if they are + * already released. + */ + if (!kref_get_unless_zero(¬ify->kref)) + continue; + notify->notify(notify, cpumask); + kref_put(¬ify->kref, notify->release); + } free_cpumask_var(cpumask); -out: - kref_put(¬ify->kref, notify->release); } /** @@ -257,34 +265,50 @@ int irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify) { struct irq_desc *desc = irq_to_desc(irq); - struct irq_affinity_notify *old_notify; unsigned long flags; - /* The release function is promised process context */ - might_sleep(); - if (!desc) return -EINVAL; - /* Complete initialisation of *notify */ - if (notify) { - notify->irq = irq; - kref_init(¬ify->kref); - INIT_WORK(¬ify->work, irq_affinity_notify); + if (!notify) { + WARN("%s called with NULL notifier - use irq_release_affinity_notifier function instead.\n", + __func__); + return -EINVAL; } + notify->irq = irq; + kref_init(¬ify->kref); + INIT_LIST_HEAD(¬ify->list); raw_spin_lock_irqsave(&desc->lock, flags); - old_notify = desc->affinity_notify; - desc->affinity_notify = notify; + list_add(¬ify->list, &desc->affinity_notify); raw_spin_unlock_irqrestore(&desc->lock, flags); - if (old_notify) - kref_put(&old_notify->kref, old_notify->release); - return 0; } EXPORT_SYMBOL_GPL(irq_set_affinity_notifier); +/** + * irq_release_affinity_notifier - Remove us from notifications + * @notify: Context for notification + */ +int irq_release_affinity_notifier(struct irq_affinity_notify *notify) +{ + struct irq_desc *desc; + unsigned long flags; + + if (!notify) + return -EINVAL; + + desc = irq_to_desc(notify->irq); + raw_spin_lock_irqsave(&desc->lock, flags); + list_del(¬ify->list); + raw_spin_unlock_irqrestore(&desc->lock, flags); + kref_put(¬ify->kref, notify->release); + + return 0; +} +EXPORT_SYMBOL(irq_release_affinity_notifier); + #ifndef CONFIG_AUTO_IRQ_AFFINITY /* * Generic version of the affinity autoselector. @@ -319,6 +343,8 @@ setup_affinity(unsigned int irq, struct irq_desc *desc, struct cpumask *mask) if (cpumask_intersects(mask, nodemask)) cpumask_and(mask, mask, nodemask); } + INIT_LIST_HEAD(&desc->affinity_notify); + INIT_WORK(&desc->affinity_work, irq_affinity_notify); irq_do_set_affinity(&desc->irq_data, mask, false); return 0; } @@ -1363,13 +1389,17 @@ EXPORT_SYMBOL_GPL(remove_irq); void free_irq(unsigned int irq, void *dev_id) { struct irq_desc *desc = irq_to_desc(irq); - +#ifdef CONFIG_SMP + struct irq_affinity_notify *notify; +#endif if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc))) return; #ifdef CONFIG_SMP - if (WARN_ON(desc->affinity_notify)) - desc->affinity_notify = NULL; + WARN_ON(!list_empty(&desc->affinity_notify)); + + list_for_each_entry(notify, &desc->affinity_notify, list) + kref_put(¬ify->kref, notify->release); #endif chip_bus_lock(desc); diff --git a/lib/cpu_rmap.c b/lib/cpu_rmap.c index 4f134d8907a7..0c8da5059f7d 100644 --- a/lib/cpu_rmap.c +++ b/lib/cpu_rmap.c @@ -235,7 +235,7 @@ void free_irq_cpu_rmap(struct cpu_rmap *rmap) for (index = 0; index < rmap->used; index++) { glue = rmap->obj[index]; - irq_set_affinity_notifier(glue->notify.irq, NULL); + irq_release_affinity_notifier(&glue->notify); } cpu_rmap_put(rmap);