From 66d0f7ec9f1038452178b1993fc07fd96d30fd38 Mon Sep 17 00:00:00 2001
From: Andreas Larsson <andreas@gaisler.com>
Date: Thu, 18 Dec 2014 13:23:23 +0100
Subject: [PATCH] sparc32: destroy_context() and switch_mm() needs to disable
 interrupts.

Load balancing can be triggered in the critical sections protected by
srmmu_context_spinlock in destroy_context() and switch_mm() and can hang
the cpu waiting for the rq lock of another cpu that in turn has called
switch_mm hangning on srmmu_context_spinlock leading to deadlock.

So, disable interrupt while taking srmmu_context_spinlock in
destroy_context() and switch_mm() so we don't deadlock.

See also commit 77b838fa1ef0 ("[SPARC64]: destroy_context() needs to disable
interrupts.")

Signed-off-by: Andreas Larsson <andreas@gaisler.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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