diff --git a/include/linux/irqdesc.h b/include/linux/irqdesc.h index a587a33363c7..dcca77c4b9d2 100644 --- a/include/linux/irqdesc.h +++ b/include/linux/irqdesc.h @@ -1,6 +1,8 @@ #ifndef _LINUX_IRQDESC_H #define _LINUX_IRQDESC_H +#include + /* * Core internal functions to deal with irq descriptors */ @@ -40,6 +42,7 @@ struct pt_regs; * IRQF_NO_SUSPEND set * @force_resume_depth: number of irqactions on a irq descriptor with * IRQF_FORCE_RESUME set + * @rcu: rcu head for delayed free * @dir: /proc/irq/ procfs entry * @name: flow handler name for /proc/interrupts output */ @@ -81,6 +84,9 @@ struct irq_desc { #endif #ifdef CONFIG_PROC_FS struct proc_dir_entry *dir; +#endif +#ifdef CONFIG_SPARSE_IRQ + struct rcu_head rcu; #endif int parent_irq; struct module *owner; diff --git a/kernel/irq/irqdesc.c b/kernel/irq/irqdesc.c index 239e2ae2c947..0409da0bcc33 100644 --- a/kernel/irq/irqdesc.c +++ b/kernel/irq/irqdesc.c @@ -159,6 +159,7 @@ static struct irq_desc *alloc_desc(int irq, int node, struct module *owner) raw_spin_lock_init(&desc->lock); lockdep_set_class(&desc->lock, &irq_desc_lock_class); + init_rcu_head(&desc->rcu); desc_set_defaults(irq, desc, node, owner); @@ -171,6 +172,15 @@ static struct irq_desc *alloc_desc(int irq, int node, struct module *owner) return NULL; } +static void delayed_free_desc(struct rcu_head *rhp) +{ + struct irq_desc *desc = container_of(rhp, struct irq_desc, rcu); + + free_masks(desc); + free_percpu(desc->kstat_irqs); + kfree(desc); +} + static void free_desc(unsigned int irq) { struct irq_desc *desc = irq_to_desc(irq); @@ -187,9 +197,12 @@ static void free_desc(unsigned int irq) delete_irq_desc(irq); mutex_unlock(&sparse_irq_lock); - free_masks(desc); - free_percpu(desc->kstat_irqs); - kfree(desc); + /* + * We free the descriptor, masks and stat fields via RCU. That + * allows demultiplex interrupts to do rcu based management of + * the child interrupts. + */ + call_rcu(&desc->rcu, delayed_free_desc); } static int alloc_descs(unsigned int start, unsigned int cnt, int node,