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;