This is useful to get an indication of how much time we spent in firmware. It's not guaranteed that the timer started at 0 on reset, so it's just an approximation, and might very well be invalid on some systems. But it's still a useful metric to have access to.
Signed-off-by: Olof Johansson <[email protected]> --- drivers/clocksource/arm_arch_timer.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c index 02fef68..c26078b 100644 --- a/drivers/clocksource/arm_arch_timer.c +++ b/drivers/clocksource/arm_arch_timer.c @@ -521,6 +521,8 @@ arch_timer_detect_rate(void __iomem *cntbase, struct device_node *np) static void arch_timer_banner(unsigned type) { + unsigned long cnt = arch_timer_read_counter(); + pr_info("Architected %s%s%s timer(s) running at %lu.%02luMHz (%s%s%s).\n", type & ARCH_CP15_TIMER ? "cp15" : "", type == (ARCH_CP15_TIMER | ARCH_MEM_TIMER) ? " and " : "", @@ -534,6 +536,8 @@ static void arch_timer_banner(unsigned type) type & ARCH_MEM_TIMER ? arch_timer_mem_use_virtual ? "virt" : "phys" : ""); + pr_info("Initial timer value: 0x%lx: %ld.%02lds\n", + cnt, cnt/arch_timer_rate, (cnt/(arch_timer_rate/100)) % 100); } u32 arch_timer_get_rate(void) -- 2.8.0.rc3.29.gb552ff8
