[3.11.y.z extended stable] Patch "genirq: Provide irq_force_affinity fallback for non-SMP" has been added to staging queue

[Luis Henriques]

This is a note to let you know that I have just added a patch titled

    genirq: Provide irq_force_affinity fallback for non-SMP

to the linux-3.11.y-queue branch of the 3.11.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.11.y-queue

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.11.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From 1c9644ba5ed20afebc90f8a38619751ed5c3ccbc Mon Sep 17 00:00:00 2001
From: Arnd Bergmann <arnd at arndb.de>
Date: Wed, 23 Apr 2014 14:49:17 +0200
Subject: genirq: Provide irq_force_affinity fallback for non-SMP

commit 4c88d7f9b0d5fb0588c3386be62115cc2eaa8f9f upstream.

Patch 01f8fa4f01d "genirq: Allow forcing cpu affinity of interrupts" added
an irq_force_affinity() function, and 30ccf03b4a6 "clocksource: Exynos_mct:
Use irq_force_affinity() in cpu bringup" subsequently uses it. However, the
driver can be used with CONFIG_SMP disabled, but the function declaration
is only available for CONFIG_SMP, leading to this build error:

drivers/clocksource/exynos_mct.c:431:3: error: implicit declaration of function 'irq_force_affinity' [-Werror=implicit-function-declaration]
   irq_force_affinity(mct_irqs[MCT_L0_IRQ + cpu], cpumask_of(cpu));

This patch introduces a dummy helper function for the non-SMP case
that always returns success, to get rid of the build error.
Since the patches causing the problem are marked for stable backports,
this one should be as well.

Signed-off-by: Arnd Bergmann <arnd at arndb.de>
Cc: Krzysztof Kozlowski <k.kozlowski at samsung.com>
Acked-by: Kukjin Kim <kgene.kim at samsung.com>
Link: http://lkml.kernel.org/r/5619084.0zmrrIUZLV@wuerfel
Signed-off-by: Thomas Gleixner <tglx at linutronix.de>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 include/linux/interrupt.h | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h
index e8401d092732..6de0f2c14ec0 100644
--- a/include/linux/interrupt.h
+++ b/include/linux/interrupt.h
@@ -308,6 +308,11 @@ static inline int irq_set_affinity(unsigned int irq, const struct cpumask *m)
 	return -EINVAL;
 }

+static inline int irq_force_affinity(unsigned int irq, const struct cpumask *cpumask)
+{
+	return 0;
+}
+
 static inline int irq_can_set_affinity(unsigned int irq)
 {
 	return 0;
--
1.9.1