From f06a1624621527ef597ae4b3b795553fc1b2eff2 Mon Sep 17 00:00:00 2001 From: Russell King Date: Wed, 15 Dec 2010 21:55:06 +0000 Subject: ARM: orion: convert sched_clock() to use new infrastructure Convert orion platforms to use the new sched_clock() infrastructure for extending 32bit counters to full 64-bit nanoseconds. Acked-by: Nicolas Pitre Signed-off-by: Russell King --- arch/arm/plat-orion/time.c | 44 +++++++++----------------------------------- 1 file changed, 9 insertions(+), 35 deletions(-) (limited to 'arch/arm/plat-orion') diff --git a/arch/arm/plat-orion/time.c b/arch/arm/plat-orion/time.c index 123f96f4194f..c3da2478b2aa 100644 --- a/arch/arm/plat-orion/time.c +++ b/arch/arm/plat-orion/time.c @@ -13,11 +13,11 @@ #include #include -#include #include #include #include #include +#include #include #include #include @@ -44,52 +44,26 @@ static u32 ticks_per_jiffy; /* * Orion's sched_clock implementation. It has a resolution of - * at least 7.5ns (133MHz TCLK) and a maximum value of 834 days. - * - * Because the hardware timer period is quite short (21 secs if - * 200MHz TCLK) and because cnt32_to_63() needs to be called at - * least once per half period to work properly, a kernel timer is - * set up to ensure this requirement is always met. + * at least 7.5ns (133MHz TCLK). */ -#define TCLK2NS_SCALE_FACTOR 8 - -static unsigned long tclk2ns_scale; +static DEFINE_CLOCK_DATA(cd); unsigned long long notrace sched_clock(void) { - unsigned long long v = cnt32_to_63(0xffffffff - readl(TIMER0_VAL)); - return (v * tclk2ns_scale) >> TCLK2NS_SCALE_FACTOR; + u32 cyc = 0xffffffff - readl(TIMER0_VAL); + return cyc_to_sched_clock(&cd, cyc, (u32)~0); } -static struct timer_list cnt32_to_63_keepwarm_timer; -static void cnt32_to_63_keepwarm(unsigned long data) +static void notrace orion_update_sched_clock(void) { - mod_timer(&cnt32_to_63_keepwarm_timer, round_jiffies(jiffies + data)); - (void) sched_clock(); + u32 cyc = 0xffffffff - readl(TIMER0_VAL); + update_sched_clock(&cd, cyc, (u32)~0); } static void __init setup_sched_clock(unsigned long tclk) { - unsigned long long v; - unsigned long data; - - v = NSEC_PER_SEC; - v <<= TCLK2NS_SCALE_FACTOR; - v += tclk/2; - do_div(v, tclk); - /* - * We want an even value to automatically clear the top bit - * returned by cnt32_to_63() without an additional run time - * instruction. So if the LSB is 1 then round it up. - */ - if (v & 1) - v++; - tclk2ns_scale = v; - - data = (0xffffffffUL / tclk / 2 - 2) * HZ; - setup_timer(&cnt32_to_63_keepwarm_timer, cnt32_to_63_keepwarm, data); - mod_timer(&cnt32_to_63_keepwarm_timer, round_jiffies(jiffies + data)); + init_sched_clock(&cd, orion_update_sched_clock, 32, tclk); } /* -- cgit v1.2.3