[PATCH 2/2] ARM: prima2: convert to common sched_clock() implementation

[Barry Song]

2012/1/16 Marc Zyngier <marc.zyngier at arm.com>:
> Prima2 has its own sched_clock() implementation, which gets in the
> way of a single zImage. Moving to the common sched_clock framework
> makes the code slightly cleaner (the mapping hack in sched_clock()
> goes away...).
>
> Cc: Barry Song <baohua.song at csr.com>
> Signed-off-by: Marc Zyngier <marc.zyngier at arm.com>

Ack. Thanks, Marc.

-barry

> ---
>  arch/arm/Kconfig             |    1 +
>  arch/arm/mach-prima2/timer.c |   21 +++++++--------------
>  2 files changed, 8 insertions(+), 14 deletions(-)
>
> diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
> index cb75734..a18550e 100644
> --- a/arch/arm/Kconfig
> +++ b/arch/arm/Kconfig
> @@ -388,6 +388,7 @@ config ARCH_PRIMA2
>        select GENERIC_CLOCKEVENTS
>        select CLKDEV_LOOKUP
>        select GENERIC_IRQ_CHIP
> +       select HAVE_SCHED_CLOCK
>        select MIGHT_HAVE_CACHE_L2X0
>        select USE_OF
>        select ZONE_DMA
> diff --git a/arch/arm/mach-prima2/timer.c b/arch/arm/mach-prima2/timer.c
> index b7a6091..0d024b1 100644
> --- a/arch/arm/mach-prima2/timer.c
> +++ b/arch/arm/mach-prima2/timer.c
> @@ -18,6 +18,7 @@
>  #include <linux/of.h>
>  #include <linux/of_address.h>
>  #include <mach/map.h>
> +#include <asm/sched_clock.h>
>  #include <asm/mach/time.h>
>
>  #define SIRFSOC_TIMER_COUNTER_LO       0x0000
> @@ -165,21 +166,9 @@ static struct irqaction sirfsoc_timer_irq = {
>  };
>
>  /* Overwrite weak default sched_clock with more precise one */
> -unsigned long long notrace sched_clock(void)
> +static u32 notrace sirfsoc_read_sched_clock(void)
>  {
> -       static int is_mapped;
> -
> -       /*
> -        * sched_clock is called earlier than .init of sys_timer
> -        * if we map timer memory in .init of sys_timer, system
> -        * will panic due to illegal memory access
> -        */
> -       if (!is_mapped) {
> -               sirfsoc_of_timer_map();
> -               is_mapped = 1;
> -       }
> -
> -       return sirfsoc_timer_read(NULL) * (NSEC_PER_SEC / CLOCK_TICK_RATE);
> +       return (u32)(sirfsoc_timer_read(NULL) & 0xffffffff);
>  }
>
>  static void __init sirfsoc_clockevent_init(void)
> @@ -210,6 +199,8 @@ static void __init sirfsoc_timer_init(void)
>        BUG_ON(rate < CLOCK_TICK_RATE);
>        BUG_ON(rate % CLOCK_TICK_RATE);
>
> +       sirfsoc_of_timer_map();
> +
>        writel_relaxed(rate / CLOCK_TICK_RATE / 2 - 1, sirfsoc_timer_base + SIRFSOC_TIMER_DIV);
>        writel_relaxed(0, sirfsoc_timer_base + SIRFSOC_TIMER_COUNTER_LO);
>        writel_relaxed(0, sirfsoc_timer_base + SIRFSOC_TIMER_COUNTER_HI);
> @@ -217,6 +208,8 @@ static void __init sirfsoc_timer_init(void)
>
>        BUG_ON(clocksource_register_hz(&sirfsoc_clocksource, CLOCK_TICK_RATE));
>
> +       setup_sched_clock(sirfsoc_read_sched_clock, 32, CLOCK_TICK_RATE);
> +
>        BUG_ON(setup_irq(sirfsoc_timer_irq.irq, &sirfsoc_timer_irq));
>
>        sirfsoc_clockevent_init();
> --
> 1.7.7.1