From: Linus Walleij <[email protected]> The sched_clock() call should be really fast so we want to avoid an extra if() clause on the read path if possible.
Implement two sched_clock_read() functions, one if the timer counts up and one if it counts down. Incidentally this also mirrors how clocksource_mmio_init() works and make things simple and easy to understand. Suggested-by: Daniel Lezcano <[email protected]> Cc: Andrew Jeffery <[email protected]> Cc: Joel Stanley <[email protected]> Cc: Jonas Jensen <[email protected]> Signed-off-by: Linus Walleij <[email protected]> Signed-off-by: Daniel Lezcano <[email protected]> --- drivers/clocksource/timer-fttmr010.c | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-) diff --git a/drivers/clocksource/timer-fttmr010.c b/drivers/clocksource/timer-fttmr010.c index a21020c..b56d7bd 100644 --- a/drivers/clocksource/timer-fttmr010.c +++ b/drivers/clocksource/timer-fttmr010.c @@ -91,13 +91,16 @@ static inline struct fttmr010 *to_fttmr010(struct clock_event_device *evt) return container_of(evt, struct fttmr010, clkevt); } -static u64 notrace fttmr010_read_sched_clock(void) +static u64 notrace fttmr010_read_sched_clock_up(void) { - if (local_fttmr->count_down) - return ~readl(local_fttmr->base + TIMER2_COUNT); return readl(local_fttmr->base + TIMER2_COUNT); } +static u64 notrace fttmr010_read_sched_clock_down(void) +{ + return ~readl(local_fttmr->base + TIMER2_COUNT); +} + static int fttmr010_timer_set_next_event(unsigned long cycles, struct clock_event_device *evt) { @@ -302,15 +305,17 @@ static int __init fttmr010_common_init(struct device_node *np, bool is_aspeed) "FTTMR010-TIMER2", fttmr010->tick_rate, 300, 32, clocksource_mmio_readl_down); + sched_clock_register(fttmr010_read_sched_clock_down, 32, + fttmr010->tick_rate); } else { writel(0, fttmr010->base + TIMER2_LOAD); clocksource_mmio_init(fttmr010->base + TIMER2_COUNT, "FTTMR010-TIMER2", fttmr010->tick_rate, 300, 32, clocksource_mmio_readl_up); + sched_clock_register(fttmr010_read_sched_clock_up, 32, + fttmr010->tick_rate); } - sched_clock_register(fttmr010_read_sched_clock, 32, - fttmr010->tick_rate); /* * Setup clockevent timer (interrupt-driven) on timer 1. -- 2.7.4
