Re: [PATCH 1/2] xen: move wallclock functions from x86 to common

[Julien Grall <julien.grall@citrix.com>]

Hi,

You forgot to CC the x86 maintainers.

Regards,

On 05/11/15 16:57, Stefano Stabellini wrote:
> Remove dummy arm implementation of wallclock_time.
> Use shared_info() in common code rather than x86-ism to access it.
> 
> Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
> Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
> ---
>  xen/arch/arm/time.c |    5 ---
>  xen/arch/x86/time.c |   92 +------------------------------------------------
>  xen/common/time.c   |   94 +++++++++++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 95 insertions(+), 96 deletions(-)
> 
> diff --git a/xen/arch/arm/time.c b/xen/arch/arm/time.c
> index 5ded30c..6207615 100644
> --- a/xen/arch/arm/time.c
> +++ b/xen/arch/arm/time.c
> @@ -280,11 +280,6 @@ void domain_set_time_offset(struct domain *d, int64_t time_offset_seconds)
>      /* XXX update guest visible wallclock time */
>  }
>  
> -struct tm wallclock_time(uint64_t *ns)
> -{
> -    return (struct tm) { 0 };
> -}
> -
>  /*
>   * Local variables:
>   * mode: C
> diff --git a/xen/arch/x86/time.c b/xen/arch/x86/time.c
> index bbb7e6c..764d7dc 100644
> --- a/xen/arch/x86/time.c
> +++ b/xen/arch/x86/time.c
> @@ -47,9 +47,6 @@ string_param("clocksource", opt_clocksource);
>  unsigned long __read_mostly cpu_khz;  /* CPU clock frequency in kHz. */
>  DEFINE_SPINLOCK(rtc_lock);
>  unsigned long pit0_ticks;
> -static unsigned long wc_sec; /* UTC time at last 'time update'. */
> -static unsigned int wc_nsec;
> -static DEFINE_SPINLOCK(wc_lock);
>  
>  struct cpu_time {
>      u64 local_tsc_stamp;
> @@ -900,37 +897,6 @@ void force_update_vcpu_system_time(struct vcpu *v)
>      __update_vcpu_system_time(v, 1);
>  }
>  
> -void update_domain_wallclock_time(struct domain *d)
> -{
> -    uint32_t *wc_version;
> -    unsigned long sec;
> -
> -    spin_lock(&wc_lock);
> -
> -    wc_version = &shared_info(d, wc_version);
> -    *wc_version = version_update_begin(*wc_version);
> -    wmb();
> -
> -    sec = wc_sec + d->time_offset_seconds;
> -    if ( likely(!has_32bit_shinfo(d)) )
> -    {
> -        d->shared_info->native.wc_sec    = sec;
> -        d->shared_info->native.wc_nsec   = wc_nsec;
> -        d->shared_info->native.wc_sec_hi = sec >> 32;
> -    }
> -    else
> -    {
> -        d->shared_info->compat.wc_sec         = sec;
> -        d->shared_info->compat.wc_nsec        = wc_nsec;
> -        d->shared_info->compat.arch.wc_sec_hi = sec >> 32;
> -    }
> -
> -    wmb();
> -    *wc_version = version_update_end(*wc_version);
> -
> -    spin_unlock(&wc_lock);
> -}
> -
>  static void update_domain_rtc(void)
>  {
>      struct domain *d;
> @@ -988,27 +954,6 @@ int cpu_frequency_change(u64 freq)
>      return 0;
>  }
>  
> -/* Set clock to <secs,usecs> after 00:00:00 UTC, 1 January, 1970. */
> -void do_settime(unsigned long secs, unsigned int nsecs, u64 system_time_base)
> -{
> -    u64 x;
> -    u32 y;
> -    struct domain *d;
> -
> -    x = SECONDS(secs) + nsecs - system_time_base;
> -    y = do_div(x, 1000000000);
> -
> -    spin_lock(&wc_lock);
> -    wc_sec  = x;
> -    wc_nsec = y;
> -    spin_unlock(&wc_lock);
> -
> -    rcu_read_lock(&domlist_read_lock);
> -    for_each_domain ( d )
> -        update_domain_wallclock_time(d);
> -    rcu_read_unlock(&domlist_read_lock);
> -}
> -
>  /* Per-CPU communication between rendezvous IRQ and softirq handler. */
>  struct cpu_calibration {
>      u64 local_tsc_stamp;
> @@ -1608,25 +1553,6 @@ void send_timer_event(struct vcpu *v)
>      send_guest_vcpu_virq(v, VIRQ_TIMER);
>  }
>  
> -/* Return secs after 00:00:00 localtime, 1 January, 1970. */
> -unsigned long get_localtime(struct domain *d)
> -{
> -    return wc_sec + (wc_nsec + NOW()) / 1000000000ULL 
> -        + d->time_offset_seconds;
> -}
> -
> -/* Return microsecs after 00:00:00 localtime, 1 January, 1970. */
> -uint64_t get_localtime_us(struct domain *d)
> -{
> -    return (SECONDS(wc_sec + d->time_offset_seconds) + wc_nsec + NOW())
> -           / 1000UL;
> -}
> -
> -unsigned long get_sec(void)
> -{
> -    return wc_sec + (wc_nsec + NOW()) / 1000000000ULL;
> -}
> -
>  /* "cmos_utc_offset" is the difference between UTC time and CMOS time. */
>  static long cmos_utc_offset; /* in seconds */
>  
> @@ -1635,7 +1561,7 @@ int time_suspend(void)
>      if ( smp_processor_id() == 0 )
>      {
>          cmos_utc_offset = -get_cmos_time();
> -        cmos_utc_offset += (wc_sec + (wc_nsec + NOW()) / 1000000000ULL);
> +        cmos_utc_offset += get_sec();
>          kill_timer(&calibration_timer);
>  
>          /* Sync platform timer stamps. */
> @@ -1715,22 +1641,6 @@ int hwdom_pit_access(struct ioreq *ioreq)
>      return 0;
>  }
>  
> -struct tm wallclock_time(uint64_t *ns)
> -{
> -    uint64_t seconds, nsec;
> -
> -    if ( !wc_sec )
> -        return (struct tm) { 0 };
> -
> -    seconds = NOW() + SECONDS(wc_sec) + wc_nsec;
> -    nsec = do_div(seconds, 1000000000);
> -
> -    if ( ns )
> -        *ns = nsec;
> -
> -    return gmtime(seconds);
> -}
> -
>  /*
>   * PV SoftTSC Emulation.
>   */
> diff --git a/xen/common/time.c b/xen/common/time.c
> index 29fdf52..306c5dc 100644
> --- a/xen/common/time.c
> +++ b/xen/common/time.c
> @@ -16,7 +16,13 @@
>   */
>  
>  #include <xen/config.h>
> +#include <xen/sched.h>
> +#include <xen/shared.h>
> +#include <xen/spinlock.h>
>  #include <xen/time.h>
> +#include <asm/div64.h>
> +#include <asm/domain.h>
> +
>  
>  /* Nonzero if YEAR is a leap year (every 4 years,
>     except every 100th isn't, and every 400th is).  */
> @@ -34,6 +40,10 @@ const unsigned short int __mon_lengths[2][12] = {
>  #define SECS_PER_HOUR (60 * 60)
>  #define SECS_PER_DAY  (SECS_PER_HOUR * 24)
>  
> +static unsigned long wc_sec; /* UTC time at last 'time update'. */
> +static unsigned int wc_nsec;
> +static DEFINE_SPINLOCK(wc_lock);
> +
>  struct tm gmtime(unsigned long t)
>  {
>      struct tm tbuf;
> @@ -85,3 +95,87 @@ struct tm gmtime(unsigned long t)
>  
>      return tbuf;
>  }
> +
> +/* Explicitly OR with 1 just in case version number gets out of sync. */
> +#define version_update_begin(v) (((v)+1)|1)
> +#define version_update_end(v)   ((v)+1)
> +
> +void update_domain_wallclock_time(struct domain *d)
> +{
> +    uint32_t *wc_version;
> +    unsigned long sec;
> +
> +    spin_lock(&wc_lock);
> +
> +    wc_version = &shared_info(d, wc_version);
> +    *wc_version = version_update_begin(*wc_version);
> +    wmb();
> +
> +    sec = wc_sec + d->time_offset_seconds;
> +    shared_info(d, wc_sec)    = sec;
> +    shared_info(d, wc_nsec)   = wc_nsec;
> +    shared_info(d, wc_sec_hi) = sec >> 32;
> +
> +    wmb();
> +    *wc_version = version_update_end(*wc_version);
> +
> +    spin_unlock(&wc_lock);
> +}
> +
> +/* Set clock to <secs,usecs> after 00:00:00 UTC, 1 January, 1970. */
> +void do_settime(unsigned long secs, unsigned int nsecs, u64 system_time_base)
> +{
> +    u64 x;
> +    u32 y;
> +    struct domain *d;
> +
> +    x = SECONDS(secs) + nsecs - system_time_base;
> +    y = do_div(x, 1000000000);
> +
> +    spin_lock(&wc_lock);
> +    wc_sec  = x;
> +    wc_nsec = y;
> +    spin_unlock(&wc_lock);
> +
> +    rcu_read_lock(&domlist_read_lock);
> +    for_each_domain ( d )
> +        update_domain_wallclock_time(d);
> +    rcu_read_unlock(&domlist_read_lock);
> +}
> +
> +/* Return secs after 00:00:00 localtime, 1 January, 1970. */
> +unsigned long get_localtime(struct domain *d)
> +{
> +    return wc_sec + (wc_nsec + NOW()) / 1000000000ULL 
> +        + d->time_offset_seconds;
> +}
> +
> +/* Return microsecs after 00:00:00 localtime, 1 January, 1970. */
> +uint64_t get_localtime_us(struct domain *d)
> +{
> +    return (SECONDS(wc_sec + d->time_offset_seconds) + wc_nsec + NOW())
> +           / 1000UL;
> +}
> +
> +unsigned long get_sec(void)
> +{
> +    return wc_sec + (wc_nsec + NOW()) / 1000000000ULL;
> +}
> +
> +struct tm wallclock_time(uint64_t *ns)
> +{
> +    uint64_t seconds, nsec;
> +
> +    if ( !wc_sec )
> +        return (struct tm) { 0 };
> +
> +    seconds = NOW() + SECONDS(wc_sec) + wc_nsec;
> +    nsec = do_div(seconds, 1000000000);
> +
> +    if ( ns )
> +        *ns = nsec;
> +
> +    return gmtime(seconds);
> +}
> +
> +
> 


-- 
Julien Grall