From 0a0a047def15b7c8bcd27671d2be2de3d37fb30d Mon Sep 17 00:00:00 2001 From: Yuriy Kolerov Date: Tue, 8 Nov 2016 10:08:32 +0300 Subject: [PATCH] ARCv2: MCIP: Use IDU_M_DISTRI_DEST mode if there is only 1 destination core 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 Signed-off-by: Vineet Gupta --- 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 6d18bb871926..f39142acc89e 100644 --- a/arch/arc/kernel/mcip.c +++ b/arch/arc/kernel/mcip.c @@ -181,6 +181,8 @@ 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)) @@ -188,8 +190,15 @@ 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);