lkml.org 
[lkml]   [2016]   [Nov]   [3]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH v3 3/3] ARCv2: MCIP: Use IDU_M_DISTRI_DEST mode if there is only 1 destination core
Date
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@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

\
 
 \ /
  Last update: 2016-11-03 13:24    [W:0.050 / U:4.580 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site