genirq: Add an extra comment about the use of affinity in irq_common_data

Affinity will have dual meaning depends on the type of the irq. If it is
a normal irq, it'll have the standard affinity meaning.

If it is an IPI, it will hold the mask of the cpus to which an IPI can be
sent.

Signed-off-by: Qais Yousef <[email protected]>
Cc: <[email protected]>
Cc: <[email protected]>
Cc: <[email protected]>
Cc: <[email protected]>
Cc: <[email protected]>
Cc: <[email protected]>
Cc: Qais Yousef <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Thomas Gleixner <[email protected]>

diff --git a/include/linux/irq.h b/include/linux/irq.h
index 3c1c96786248cb02d2d9792cce455892323ef275..0817afd0d719ab1b41176bdfa44b6dadaee6dc6e 100644 (file)
--- a/include/linux/irq.h
+++ b/include/linux/irq.h
@@ -133,7 +133,9 @@ struct irq_domain;
  *                     Use accessor functions to deal with it
  * @node:              node index useful for balancing
  * @handler_data:      per-IRQ data for the irq_chip methods
- * @affinity:          IRQ affinity on SMP
+ * @affinity:          IRQ affinity on SMP. If this is an IPI
+ *                     related irq, then this is the mask of the
+ *                     CPUs to which an IPI can be sent.
  * @msi_desc:          MSI descriptor
  */
 struct irq_common_data {