[tip:irq/core] genirq: irqchip: Add mask to block out invalid irqs

[tip-bot for Grant Likely]

Commit-ID:  e8bd834f73714378ef110a64287db1b77033c8da
Gitweb:     http://git.kernel.org/tip/e8bd834f73714378ef110a64287db1b77033c8da
Author:     Grant Likely <grant.likely@xxxxxxxxxx>
AuthorDate: Wed, 29 May 2013 03:10:52 +0100
Committer:  Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitDate: Wed, 29 May 2013 10:57:11 +0200

genirq: irqchip: Add mask to block out invalid irqs

Some controllers have irqs that aren't wired up and must never be used.
For the generic chip attached to an irq_domain this provides a mask that
can be used to block out particular irqs so that they never get mapped.

Signed-off-by: Grant Likely <grant.likely@xxxxxxxxxx>
Link: http://lkml.kernel.org/r/1369793454-19197-2-git-send-email-grant.likely@xxxxxxxxxx
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
---
 include/linux/irq.h       | 2 ++
 kernel/irq/generic-chip.c | 3 +++
 2 files changed, 5 insertions(+)

diff --git a/include/linux/irq.h b/include/linux/irq.h
index af7052c..298a9b9 100644
--- a/include/linux/irq.h
+++ b/include/linux/irq.h
@@ -679,6 +679,7 @@ struct irq_chip_type {
  * @num_ct:		Number of available irq_chip_type instances (usually 1)
  * @private:		Private data for non generic chip callbacks
  * @installed:		bitfield to denote installed interrupts
+ * @unused:		bitfield to denote unused interrupts
  * @domain:		irq domain pointer
  * @list:		List head for keeping track of instances
  * @chip_types:		Array of interrupt irq_chip_types
@@ -702,6 +703,7 @@ struct irq_chip_generic {
 	unsigned int		num_ct;
 	void			*private;
 	unsigned long		installed;
+	unsigned long		unused;
 	struct irq_domain	*domain;
 	struct list_head	list;
 	struct irq_chip_type	chip_types[0];
diff --git a/kernel/irq/generic-chip.c b/kernel/irq/generic-chip.c
index 8743d62..95575d8 100644
--- a/kernel/irq/generic-chip.c
+++ b/kernel/irq/generic-chip.c
@@ -359,6 +359,9 @@ static int irq_map_generic_chip(struct irq_domain *d, unsigned int virq,
 
 	idx = hw_irq % dgc->irqs_per_chip;
 
+	if (test_bit(idx, &gc->unused))
+		return -ENOTSUPP;
+
 	if (test_bit(idx, &gc->installed))
 		return -EBUSY;
 
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/