IPIs are always assumed to be consecutively allocated, hence virqs and hwirqs
can be inferred by using CPU id as an offset. But the first cpu doesn't always
have to start at position 0. ipi_offset stores the position of the first cpu so
that we can easily calculate the virq or hwirq of an IPI associated with a
specific cpu.
Signed-off-by: Qais Yousef <qais.yousef@xxxxxxxxxx>
---
include/linux/irq.h | 2 ++
1 file changed, 2 insertions(+)
diff --git a/include/linux/irq.h b/include/linux/irq.h
index 14f1c036119c..6bcbd11207ea 100644
--- a/include/linux/irq.h
+++ b/include/linux/irq.h
@@ -150,6 +150,7 @@ struct ipi_mapping {
* @ipi_mapping: Contains the hwirq mapping of IPIs.
* The use of this struct is optional and not all irqchips
* will use it.
+ * @ipi_offset: offset of first IPI in the mask
*/
struct irq_common_data {
unsigned int state_use_accessors;
@@ -161,6 +162,7 @@ struct irq_common_data {
cpumask_var_t affinity;
#ifdef CONFIG_GENERIC_IRQ_IPI
struct ipi_mapping *ipi_map;
+ unsigned int ipi_offset;
#endif
};
--
2.1.0
