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Diffstat (limited to 'arch/arm/kernel/arch_timer.c')
-rw-r--r--arch/arm/kernel/arch_timer.c29
1 files changed, 13 insertions, 16 deletions
diff --git a/arch/arm/kernel/arch_timer.c b/arch/arm/kernel/arch_timer.c
index d957a51435d8..59dcdced6e30 100644
--- a/arch/arm/kernel/arch_timer.c
+++ b/arch/arm/kernel/arch_timer.c
@@ -22,9 +22,11 @@ static unsigned long arch_timer_read_counter_long(void)
return arch_timer_read_counter();
}
-static u32 arch_timer_read_counter_u32(void)
+static u32 sched_clock_mult __read_mostly;
+
+static unsigned long long notrace arch_timer_sched_clock(void)
{
- return arch_timer_read_counter();
+ return arch_timer_read_counter() * sched_clock_mult;
}
static struct delay_timer arch_delay_timer;
@@ -37,25 +39,20 @@ static void __init arch_timer_delay_timer_register(void)
register_current_timer_delay(&arch_delay_timer);
}
-int __init arch_timer_of_register(void)
+int __init arch_timer_arch_init(void)
{
- int ret;
+ u32 arch_timer_rate = arch_timer_get_rate();
- ret = arch_timer_init();
- if (ret)
- return ret;
+ if (arch_timer_rate == 0)
+ return -ENXIO;
arch_timer_delay_timer_register();
- return 0;
-}
-
-int __init arch_timer_sched_clock_init(void)
-{
- if (arch_timer_get_rate() == 0)
- return -ENXIO;
+ /* Cache the sched_clock multiplier to save a divide in the hot path. */
+ sched_clock_mult = NSEC_PER_SEC / arch_timer_rate;
+ sched_clock_func = arch_timer_sched_clock;
+ pr_info("sched_clock: ARM arch timer >56 bits at %ukHz, resolution %uns\n",
+ arch_timer_rate / 1000, sched_clock_mult);
- setup_sched_clock(arch_timer_read_counter_u32,
- 32, arch_timer_get_rate());
return 0;
}