ARC linux uses 2 distribution modes for common interrupts: round robin
mode (IDU_M_DISTRI_RR) and a simple destination mode (IDU_M_DISTRI_DEST).
The first one is used when more than 1 cores may handle a common interrupt
and the second one is used when only 1 core may handle a common interrupt.
However idu_irq_set_affinity() always sets IDU_M_DISTRI_RR for all affinity
values. But there is no sense in setting of such mode if only 1 core must
handle a common interrupt.
Signed-off-by: Yuriy Kolerov <yuriy.kolerov at synopsys.com>
---
arch/arc/kernel/mcip.c | 13 +++++++++++--
1 file changed, 11 insertions(+), 2 deletions(-)
diff --git a/arch/arc/kernel/mcip.c b/arch/arc/kernel/mcip.c
index 4f4f04b..90f9934 100644
--- a/arch/arc/kernel/mcip.c
+++ b/arch/arc/kernel/mcip.c
@@ -193,6 +193,8 @@ idu_irq_set_affinity(struct irq_data *data, const struct cpumask *cpumask,
{
unsigned long flags;
cpumask_t online;
+ unsigned int destination_bits;
+ unsigned int distribution_mode;
/* errout if no online cpu per @cpumask */
if (!cpumask_and(&online, cpumask, cpu_online_mask))
@@ -200,8 +202,15 @@ idu_irq_set_affinity(struct irq_data *data, const struct cpumask *cpumask,
raw_spin_lock_irqsave(&mcip_lock, flags);
- idu_set_dest(data->hwirq, cpumask_bits(&online)[0]);
- idu_set_mode(data->hwirq, IDU_M_TRIG_LEVEL, IDU_M_DISTRI_RR);
+ destination_bits = cpumask_bits(&online)[0];
+ idu_set_dest(data->hwirq, destination_bits);
+
+ if (ffs(destination_bits) == fls(destination_bits))
+ distribution_mode = IDU_M_DISTRI_DEST;
+ else
+ distribution_mode = IDU_M_DISTRI_RR;
+
+ idu_set_mode(data->hwirq, IDU_M_TRIG_LEVEL, distribution_mode);
raw_spin_unlock_irqrestore(&mcip_lock, flags);
--
2.7.4
