[PATCH 3.2 109/131] sparc64: Make itc_sync_lock raw

From: Ben Hutchings
Date: Thu Sep 11 2014 - 09:17:22 EST


3.2.63-rc1 review patch. If anyone has any objections, please let me know.

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

From: Kirill Tkhai <tkhai@xxxxxxxxx>

[ Upstream commit 49b6c01f4c1de3b5e5427ac5aba80f9f6d27837a ]

One more place where we must not be able
to be preempted or to be interrupted in RT.

Always actually disable interrupts during
synchronization cycle.

Signed-off-by: Kirill Tkhai <tkhai@xxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
arch/sparc/kernel/smp_64.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/arch/sparc/kernel/smp_64.c b/arch/sparc/kernel/smp_64.c
index e21d3c0d..ffd1245 100644
--- a/arch/sparc/kernel/smp_64.c
+++ b/arch/sparc/kernel/smp_64.c
@@ -151,7 +151,7 @@ void cpu_panic(void)
#define NUM_ROUNDS 64 /* magic value */
#define NUM_ITERS 5 /* likewise */

-static DEFINE_SPINLOCK(itc_sync_lock);
+static DEFINE_RAW_SPINLOCK(itc_sync_lock);
static unsigned long go[SLAVE + 1];

#define DEBUG_TICK_SYNC 0
@@ -259,7 +259,7 @@ static void smp_synchronize_one_tick(int cpu)
go[MASTER] = 0;
membar_safe("#StoreLoad");

- spin_lock_irqsave(&itc_sync_lock, flags);
+ raw_spin_lock_irqsave(&itc_sync_lock, flags);
{
for (i = 0; i < NUM_ROUNDS*NUM_ITERS; i++) {
while (!go[MASTER])
@@ -270,7 +270,7 @@ static void smp_synchronize_one_tick(int cpu)
membar_safe("#StoreLoad");
}
}
- spin_unlock_irqrestore(&itc_sync_lock, flags);
+ raw_spin_unlock_irqrestore(&itc_sync_lock, flags);
}

#if defined(CONFIG_SUN_LDOMS) && defined(CONFIG_HOTPLUG_CPU)

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