[PATCH v3 2/4] genirq: Add chip hooks for taking CPUs on/off line.

From: David Daney
Date: Fri Mar 25 2011 - 15:39:50 EST


Signed-off-by: David Daney <ddaney@xxxxxxxxxxxxxxxxxx>
---
include/linux/irq.h | 8 ++++++
kernel/irq/chip.c | 62 +++++++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 70 insertions(+), 0 deletions(-)

diff --git a/include/linux/irq.h b/include/linux/irq.h
index 1d3577f..f517b25 100644
--- a/include/linux/irq.h
+++ b/include/linux/irq.h
@@ -270,6 +270,8 @@ static inline bool irqd_can_move_in_process_context(struct irq_data *d)
* @irq_set_wake: enable/disable power-management wake-on of an IRQ
* @irq_bus_lock: function to lock access to slow bus (i2c) chips
* @irq_bus_sync_unlock:function to sync and unlock slow bus (i2c) chips
+ * @irq_cpu_online: configure an interrupt source for a secondary CPU
+ * @irq_cpu_offline: un-configure an interrupt source for a secondary CPU
* @flags: chip specific flags
*
* @release: release function solely used by UML
@@ -317,6 +319,9 @@ struct irq_chip {
void (*irq_bus_lock)(struct irq_data *data);
void (*irq_bus_sync_unlock)(struct irq_data *data);

+ void (*irq_cpu_online)(struct irq_data *data, bool enabled);
+ void (*irq_cpu_offline)(struct irq_data *data, bool enabled);
+
unsigned long flags;

/* Currently used only by UML, might disappear one day.*/
@@ -360,6 +365,9 @@ struct irqaction;
extern int setup_irq(unsigned int irq, struct irqaction *new);
extern void remove_irq(unsigned int irq, struct irqaction *act);

+extern void irq_cpu_online(void);
+extern void irq_cpu_offline(void);
+
#ifdef CONFIG_GENERIC_HARDIRQS

#if defined(CONFIG_SMP) && defined(CONFIG_GENERIC_PENDING_IRQ)
diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c
index 54d9aab..5a385a9 100644
--- a/kernel/irq/chip.c
+++ b/kernel/irq/chip.c
@@ -695,3 +695,65 @@ void irq_modify_status(unsigned int irq, unsigned long clr, unsigned long set)

irq_put_desc_unlock(desc, flags);
}
+
+/**
+ * irq_cpu_online - Invoke all irq_cpu_online functions.
+ *
+ * Iterate through all irqs and invoke the chip.irq_cpu_online()
+ * for each.
+ */
+void irq_cpu_online(void)
+{
+ struct irq_desc *desc;
+ struct irq_chip *chip;
+ unsigned int irq;
+ unsigned long flags;
+
+ for_each_active_irq(irq) {
+ desc = irq_to_desc(irq);
+ if (!desc)
+ continue;
+
+ raw_spin_lock_irqsave(&desc->lock, flags);
+
+ chip = irq_data_get_irq_chip(&desc->irq_data);
+
+ if (chip && chip->irq_cpu_online) {
+ bool enabled = !(desc->istate & IRQS_DISABLED);
+ chip->irq_cpu_online(&desc->irq_data, enabled);
+ }
+
+ raw_spin_unlock_irqrestore(&desc->lock, flags);
+ }
+}
+
+/**
+ * irq_cpu_offline - Invoke all irq_cpu_offline functions.
+ *
+ * Iterate through all irqs and invoke the chip.irq_cpu_offline()
+ * for each.
+ */
+void irq_cpu_offline(void)
+{
+ struct irq_desc *desc;
+ struct irq_chip *chip;
+ unsigned int irq;
+ unsigned long flags;
+
+ for_each_active_irq(irq) {
+ desc = irq_to_desc(irq);
+ if (!desc)
+ continue;
+
+ raw_spin_lock_irqsave(&desc->lock, flags);
+
+ chip = irq_data_get_irq_chip(&desc->irq_data);
+
+ if (chip && chip->irq_cpu_offline) {
+ bool enabled = !(desc->istate & IRQS_DISABLED);
+ chip->irq_cpu_offline(&desc->irq_data, enabled);
+ }
+
+ raw_spin_unlock_irqrestore(&desc->lock, flags);
+ }
+}
--
1.7.2.3

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