From 53a2dd7f567cebda868b0765e2659f7930ba958f Mon Sep 17 00:00:00 2001 From: Catalin Marinas Date: Wed, 10 Dec 2014 11:02:09 +0000 Subject: [PATCH] clocksource: arch_timer: Only use the virtual counter (CNTVCT) on arm64 Origin: https://git.kernel.org/linus/d6ad36913083d683aad4e02e53580c995f1a6ede Commit 0b46b8a718c6 (clocksource: arch_timer: Fix code to use physical timers when requested) introduces the use of physical counters in the ARM architected timer driver. However, he arm64 kernel uses CNTVCT in VDSO. When booting in EL2, the kernel switches to the physical timers to make things easier for KVM but it continues to use the virtual counter both in user and kernel. While in such scenario CNTVCT == CNTPCT (since CNTVOFF is initialised by the kernel to 0), we want to spot firmware bugs corrupting CNTVOFF early (which would affect CNTVCT). Signed-off-by: Catalin Marinas Tested-by: Yingjoe Chen Cc: Daniel Lezcano Signed-off-by: Arnd Bergmann --- drivers/clocksource/arm_arch_timer.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c index 506949d..499cb1d 100644 --- a/drivers/clocksource/arm_arch_timer.c +++ b/drivers/clocksource/arm_arch_timer.c @@ -430,7 +430,7 @@ static void __init arch_counter_register(unsigned type) /* Register the CP15 based counter if we have one */ if (type & ARCH_CP15_TIMER) { - if (arch_timer_use_virtual) + if (IS_ENABLED(CONFIG_ARM64) || arch_timer_use_virtual) arch_timer_read_counter = arch_counter_get_cntvct; else arch_timer_read_counter = arch_counter_get_cntpct; -- 1.7.10.4