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-rw-r--r--include/linux/interrupt.h1
-rw-r--r--include/linux/irqdesc.h6
-rw-r--r--kernel/irq/chip.c8
-rw-r--r--kernel/irq/irqdesc.c19
-rw-r--r--kernel/irq/manage.c25
5 files changed, 52 insertions, 7 deletions
diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h
index ad16809c8596..cb30edbfe9fc 100644
--- a/include/linux/interrupt.h
+++ b/include/linux/interrupt.h
@@ -195,6 +195,7 @@ extern void disable_irq(unsigned int irq);
extern void disable_percpu_irq(unsigned int irq);
extern void enable_irq(unsigned int irq);
extern void enable_percpu_irq(unsigned int irq, unsigned int type);
+extern bool irq_percpu_is_enabled(unsigned int irq);
extern void irq_wake_thread(unsigned int irq, void *dev_id);
/* The following three functions are for the core kernel use only. */
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 <linux/rcupdate.h>
+
/*
* 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
*/
@@ -82,6 +85,9 @@ struct irq_desc {
#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;
const char *name;
diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c
index 15206453b12a..05e29de57933 100644
--- a/kernel/irq/chip.c
+++ b/kernel/irq/chip.c
@@ -338,7 +338,6 @@ void handle_nested_irq(unsigned int irq)
raw_spin_lock_irq(&desc->lock);
desc->istate &= ~(IRQS_REPLAY | IRQS_WAITING);
- kstat_incr_irqs_this_cpu(desc);
action = desc->action;
if (unlikely(!action || irqd_irq_disabled(&desc->irq_data))) {
@@ -346,6 +345,7 @@ void handle_nested_irq(unsigned int irq)
goto out_unlock;
}
+ kstat_incr_irqs_this_cpu(desc);
irqd_set(&desc->irq_data, IRQD_IRQ_INPROGRESS);
raw_spin_unlock_irq(&desc->lock);
@@ -412,13 +412,13 @@ void handle_simple_irq(struct irq_desc *desc)
goto out_unlock;
desc->istate &= ~(IRQS_REPLAY | IRQS_WAITING);
- kstat_incr_irqs_this_cpu(desc);
if (unlikely(!desc->action || irqd_irq_disabled(&desc->irq_data))) {
desc->istate |= IRQS_PENDING;
goto out_unlock;
}
+ kstat_incr_irqs_this_cpu(desc);
handle_irq_event(desc);
out_unlock:
@@ -462,7 +462,6 @@ void handle_level_irq(struct irq_desc *desc)
goto out_unlock;
desc->istate &= ~(IRQS_REPLAY | IRQS_WAITING);
- kstat_incr_irqs_this_cpu(desc);
/*
* If its disabled or no action available
@@ -473,6 +472,7 @@ void handle_level_irq(struct irq_desc *desc)
goto out_unlock;
}
+ kstat_incr_irqs_this_cpu(desc);
handle_irq_event(desc);
cond_unmask_irq(desc);
@@ -532,7 +532,6 @@ void handle_fasteoi_irq(struct irq_desc *desc)
goto out;
desc->istate &= ~(IRQS_REPLAY | IRQS_WAITING);
- kstat_incr_irqs_this_cpu(desc);
/*
* If its disabled or no action available
@@ -544,6 +543,7 @@ void handle_fasteoi_irq(struct irq_desc *desc)
goto out;
}
+ kstat_incr_irqs_this_cpu(desc);
if (desc->istate & IRQS_ONESHOT)
mask_irq(desc);
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 @@ err_desc:
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,
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index 0eebaeef317b..c84670c373f9 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -1743,6 +1743,31 @@ out:
}
EXPORT_SYMBOL_GPL(enable_percpu_irq);
+/**
+ * irq_percpu_is_enabled - Check whether the per cpu irq is enabled
+ * @irq: Linux irq number to check for
+ *
+ * Must be called from a non migratable context. Returns the enable
+ * state of a per cpu interrupt on the current cpu.
+ */
+bool irq_percpu_is_enabled(unsigned int irq)
+{
+ unsigned int cpu = smp_processor_id();
+ struct irq_desc *desc;
+ unsigned long flags;
+ bool is_enabled;
+
+ desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU);
+ if (!desc)
+ return false;
+
+ is_enabled = cpumask_test_cpu(cpu, desc->percpu_enabled);
+ irq_put_desc_unlock(desc, flags);
+
+ return is_enabled;
+}
+EXPORT_SYMBOL_GPL(irq_percpu_is_enabled);
+
void disable_percpu_irq(unsigned int irq)
{
unsigned int cpu = smp_processor_id();