ARM: 5995/1: ARM: Add L2x0 outer_sync() support (3/4)

The L2x0 cache controllers need to explicitly drain their write buffer
even for Normal Noncacheable memory accesses.
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

arch/arm/mm/Kconfig

@@ -763,6 +763,7 @@ config CACHE_L2X0
 		   REALVIEW_EB_A9MP || ARCH_MX35 || ARCH_MX31 || MACH_REALVIEW_PBX || ARCH_NOMADIK || ARCH_OMAP4
 	default y
 	select OUTER_CACHE
+	select OUTER_CACHE_SYNC
 	help
 	  This option enables the L2x0 PrimeCell.
 

arch/arm/mm/cache-l2x0.c

@@ -93,6 +93,15 @@ static inline void l2x0_flush_line(unsigned long addr)
 }
 #endif
 
+static void l2x0_cache_sync(void)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&l2x0_lock, flags);
+	cache_sync();
+	spin_unlock_irqrestore(&l2x0_lock, flags);
+}
+
 static inline void l2x0_inv_all(void)
 {
 	unsigned long flags;
@@ -225,6 +234,7 @@ void __init l2x0_init(void __iomem *base, __u32 aux_val, __u32 aux_mask)
 	outer_cache.inv_range = l2x0_inv_range;
 	outer_cache.clean_range = l2x0_clean_range;
 	outer_cache.flush_range = l2x0_flush_range;
+	outer_cache.sync = l2x0_cache_sync;
 
 	printk(KERN_INFO "L2X0 cache controller enabled\n");
 }