On Mon, 4 Jul 2022 14:13:26 +0200
Nico Boehr <nrb@xxxxxxxxxxxxx> wrote:
> Upcoming changes will make use of the CPU timer, so add a convenience
> function to set the CPU timer.
>
> Since shifts for both CPU timer and TOD clock are the same, introduce a
> new define TIMING_S390_SHIFT_US. The respective shifts for CPU timer and
> TOD clock reference it, so the semantic difference between the two
> defines is kept.
>
> Signed-off-by: Nico Boehr <nrb@xxxxxxxxxxxxx>
> ---
> lib/s390x/asm/time.h | 16 +++++++++++++++-
> 1 file changed, 15 insertions(+), 1 deletion(-)
>
> diff --git a/lib/s390x/asm/time.h b/lib/s390x/asm/time.h
> index 7652a151e87a..9ae364afb8a3 100644
> --- a/lib/s390x/asm/time.h
> +++ b/lib/s390x/asm/time.h
> @@ -11,9 +11,13 @@
> #ifndef _ASMS390X_TIME_H_
> #define _ASMS390X_TIME_H_
>
> -#define STCK_SHIFT_US (63 - 51)
> +#define TIMING_S390_SHIFT_US (63 - 51)
I would call it S390_CLOCK_SHIFT_US
> +
> +#define STCK_SHIFT_US TIMING_S390_SHIFT_US
> #define STCK_MAX ((1UL << 52) - 1)
>
> +#define CPU_TIMER_SHIFT_US TIMING_S390_SHIFT_US
> +
> static inline uint64_t get_clock_us(void)
> {
> uint64_t clk;
> @@ -45,4 +49,14 @@ static inline void mdelay(unsigned long ms)
> udelay(ms * 1000);
> }
>
> +static inline void cpu_timer_set(int64_t timeout_ms)
I would call the function cpu_timer_set_ms
so that it's clear what unit goes in, and it makes things easier if in
the future someone needs a _us version
> +{
> + int64_t timer_value = (timeout_ms * 1000) << CPU_TIMER_SHIFT_US;
> + asm volatile (
> + "spt %[timer_value]\n"
> + :
> + : [timer_value] "Q" (timer_value)
> + );
> +}
> +
> #endif
