From 3592d7e002438980f9ce4a399f21ec94cbf071ea Mon Sep 17 00:00:00 2001 From: Nicolas Pitre Date: Tue, 24 Jun 2014 18:34:38 +0100 Subject: [PATCH] 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 Reviewed-by: Kevin Hilman Signed-off-by: Russell King --- arch/arm/mach-vexpress/tc2_pm.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) diff --git a/arch/arm/mach-vexpress/tc2_pm.c b/arch/arm/mach-vexpress/tc2_pm.c index b743a0a..54a9fff 100644 --- 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; -- 2.7.4