ARM: 5845/1: l2x0: check whether l2x0 already enabled

If running in non-secure mode accessing
some registers of l2x0 will fault. So
check if l2x0 is already enabled, if so
do not access those secure registers.
Signed-off-by: Nsrinidhi kasagar <srinidhi.kasagar@stericsson.com>
Acked-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

arch/arm/mm/cache-l2x0.c

@@ -99,8 +99,14 @@ void __init l2x0_init(void __iomem *base, __u32 aux_val, __u32 aux_mask)
 
 	l2x0_base = base;
 
-	/* disable L2X0 */
-	writel(0, l2x0_base + L2X0_CTRL);
+	/*
+	 * Check if l2x0 controller is already enabled.
+	 * If you are booting from non-secure mode
+	 * accessing the below registers will fault.
+	 */
+	if (!(readl(l2x0_base + L2X0_CTRL) & 1)) {
+
+		/* l2x0 controller is disabled */
 
 		aux = readl(l2x0_base + L2X0_AUX_CTRL);
 		aux &= aux_mask;
@@ -111,6 +117,7 @@ void __init l2x0_init(void __iomem *base, __u32 aux_val, __u32 aux_mask)
 
 		/* enable L2X0 */
 		writel(1, l2x0_base + L2X0_CTRL);
+	}
 
 	outer_cache.inv_range = l2x0_inv_range;
 	outer_cache.clean_range = l2x0_clean_range;