[PATCH 3.8 07/65] genirq: Provide irq_force_affinity fallback for non-SMP

[Kamal Mostafa]

3.8.13.25 -stable review patch.  If anyone has any objections, please let me know.

------------------

From: Arnd Bergmann <arnd at arndb.de>

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: Kamal Mostafa <kamal 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 e8401d0..6de0f2c 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