From 0762097625711e829a008b64f42dc0ec74abb284 Mon Sep 17 00:00:00 2001
From: Catalin Marinas <catalin.marinas@arm.com>
Date: Fri, 20 Jul 2007 11:42:40 +0100
Subject: [PATCH] [ARM] 4500/1: Add locking around the background L2x0 cache
 operations

The background operations of the L2x0 cache controllers are aborted if
another operation is issued on the same or different core. This patch
protects the maintenance operation issuing/polling with a spinlock.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
---
 arch/arm/mm/cache-l2x0.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/arch/arm/mm/cache-l2x0.c b/arch/arm/mm/cache-l2x0.c
index 08a36f1b35d2..b4e9b734e0bd 100644
--- a/arch/arm/mm/cache-l2x0.c
+++ b/arch/arm/mm/cache-l2x0.c
@@ -17,6 +17,7 @@
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  */
 #include <linux/init.h>
+#include <linux/spinlock.h>
 
 #include <asm/cacheflush.h>
 #include <asm/io.h>
@@ -25,14 +26,19 @@
 #define CACHE_LINE_SIZE		32
 
 static void __iomem *l2x0_base;
+static DEFINE_SPINLOCK(l2x0_lock);
 
 static inline void sync_writel(unsigned long val, unsigned long reg,
 			       unsigned long complete_mask)
 {
+	unsigned long flags;
+
+	spin_lock_irqsave(&l2x0_lock, flags);
 	writel(val, l2x0_base + reg);
 	/* wait for the operation to complete */
 	while (readl(l2x0_base + reg) & complete_mask)
 		;
+	spin_unlock_irqrestore(&l2x0_lock, flags);
 }
 
 static inline void cache_sync(void)
-- 
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