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: srinidhi kasagar <srinidhi.kasagar@stericsson.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 16 insertions, 9 deletions

diff --git a/arch/arm/mm/cache-l2x0.c b/arch/arm/mm/cache-l2x0.c
index b480f1d3591f..747f9a9021bb 100644
--- a/arch/arm/mm/cache-l2x0.c
+++ b/arch/arm/mm/cache-l2x0.c
@@ -99,18 +99,25 @@ 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)) {
 
-	aux = readl(l2x0_base + L2X0_AUX_CTRL);
-	aux &= aux_mask;
-	aux |= aux_val;
-	writel(aux, l2x0_base + L2X0_AUX_CTRL);
+		/* l2x0 controller is disabled */
 
-	l2x0_inv_all();
+		aux = readl(l2x0_base + L2X0_AUX_CTRL);
+		aux &= aux_mask;
+		aux |= aux_val;
+		writel(aux, l2x0_base + L2X0_AUX_CTRL);
 
-	/* enable L2X0 */
-	writel(1, l2x0_base + L2X0_CTRL);
+		l2x0_inv_all();
+
+		/* enable L2X0 */
+		writel(1, l2x0_base + L2X0_CTRL);
+	}
 
 	outer_cache.inv_range = l2x0_inv_range;
 	outer_cache.clean_range = l2x0_clean_range;