ARM: 8082/1: TC2: test the MCPM loopback during boot

This is not strictly needed on TC2 but still a good idea to exercise
that code.

Signed-off-by: nicolas Pitre <nico@linaro.org>
Reviewed-by: Kevin Hilman <khilman@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

diff --git a/arch/arm/mach-vexpress/tc2_pm.c b/arch/arm/mach-vexpress/tc2_pm.c
index b743a0ae02cedb3abd31d9d2688e0825b02ab4cb..54a9fff77c7d99085f1417ee4a2ce04701c1049b 100644 (file)
--- a/arch/arm/mach-vexpress/tc2_pm.c
+++ b/arch/arm/mach-vexpress/tc2_pm.c
@@ -323,6 +323,21 @@ static void __naked tc2_pm_power_up_setup(unsigned int affinity_level)
 "      b       cci_enable_port_for_self ");
 }
 
+static void __init tc2_cache_off(void)
+{
+       pr_info("TC2: disabling cache during MCPM loopback test\n");
+       if (read_cpuid_part_number() == ARM_CPU_PART_CORTEX_A15) {
+               /* disable L2 prefetching on the Cortex-A15 */
+               asm volatile(
+               "mcr    p15, 1, %0, c15, c0, 3 \n\t"
+               "isb    \n\t"
+               "dsb    "
+               : : "r" (0x400) );
+       }
+       v7_exit_coherency_flush(all);
+       cci_disable_port_by_cpu(read_cpuid_mpidr());
+}
+
 static int __init tc2_pm_init(void)
 {
        int ret, irq;
@@ -370,6 +385,8 @@ static int __init tc2_pm_init(void)
        ret = mcpm_platform_register(&tc2_pm_power_ops);
        if (!ret) {
                mcpm_sync_init(tc2_pm_power_up_setup);
+               /* test if we can (re)enable the CCI on our own */
+               BUG_ON(mcpm_loopback(tc2_cache_off) != 0);
                pr_info("TC2 power management initialized\n");
        }
        return ret;