[PATCH v10 05/20] xen: rework xen timer so it can be used early in boot process
Will Andrews
will at firepipe.net
Tue Jan 14 15:30:36 UTC 2014
Looks good to me. It appears to go with your PATCH v10 06/20, and
your commit log should note the dependency directly.
Thanks!
--Will.
On Tue, Jan 14, 2014 at 7:59 AM, Roger Pau Monne <roger.pau at citrix.com> wrote:
> This should not introduce any functional change, and makes the
> functions suitable to be called before we have actually mapped the
> vcpu_info struct on a per-cpu basis.
> ---
> sys/dev/xen/timer/timer.c | 29 ++++++++++++++++++++---------
> 1 files changed, 20 insertions(+), 9 deletions(-)
>
> diff --git a/sys/dev/xen/timer/timer.c b/sys/dev/xen/timer/timer.c
> index 354085b..b2f6bcd 100644
> --- a/sys/dev/xen/timer/timer.c
> +++ b/sys/dev/xen/timer/timer.c
> @@ -230,22 +230,22 @@ xen_fetch_vcpu_tinfo(struct vcpu_time_info *dst, struct vcpu_time_info *src)
> /**
> * \brief Get the current time, in nanoseconds, since the hypervisor booted.
> *
> + * \param vcpu vcpu_info structure to fetch the time from.
> + *
> * \note This function returns the current CPU's idea of this value, unless
> * it happens to be less than another CPU's previously determined value.
> */
> static uint64_t
> -xen_fetch_vcpu_time(void)
> +xen_fetch_vcpu_time(struct vcpu_info *vcpu)
> {
> struct vcpu_time_info dst;
> struct vcpu_time_info *src;
> uint32_t pre_version;
> uint64_t now;
> volatile uint64_t last;
> - struct vcpu_info *vcpu = DPCPU_GET(vcpu_info);
>
> src = &vcpu->time;
>
> - critical_enter();
> do {
> pre_version = xen_fetch_vcpu_tinfo(&dst, src);
> barrier();
> @@ -266,16 +266,19 @@ xen_fetch_vcpu_time(void)
> }
> } while (!atomic_cmpset_64(&xen_timer_last_time, last, now));
>
> - critical_exit();
> -
> return (now);
> }
>
> static uint32_t
> xentimer_get_timecount(struct timecounter *tc)
> {
> + uint32_t xen_time;
>
> - return ((uint32_t)xen_fetch_vcpu_time() & UINT_MAX);
> + critical_enter();
> + xen_time = (uint32_t)xen_fetch_vcpu_time(DPCPU_GET(vcpu_info)) & UINT_MAX;
> + critical_exit();
> +
> + return (xen_time);
> }
>
> /**
> @@ -305,7 +308,12 @@ xen_fetch_wallclock(struct timespec *ts)
> static void
> xen_fetch_uptime(struct timespec *ts)
> {
> - uint64_t uptime = xen_fetch_vcpu_time();
> + uint64_t uptime;
> +
> + critical_enter();
> + uptime = xen_fetch_vcpu_time(DPCPU_GET(vcpu_info));
> + critical_exit();
> +
> ts->tv_sec = uptime / NSEC_IN_SEC;
> ts->tv_nsec = uptime % NSEC_IN_SEC;
> }
> @@ -354,7 +362,7 @@ xentimer_intr(void *arg)
> struct xentimer_softc *sc = (struct xentimer_softc *)arg;
> struct xentimer_pcpu_data *pcpu = DPCPU_PTR(xentimer_pcpu);
>
> - pcpu->last_processed = xen_fetch_vcpu_time();
> + pcpu->last_processed = xen_fetch_vcpu_time(DPCPU_GET(vcpu_info));
> if (pcpu->timer != 0 && sc->et.et_active)
> sc->et.et_event_cb(&sc->et, sc->et.et_arg);
>
> @@ -415,7 +423,10 @@ xentimer_et_start(struct eventtimer *et,
> do {
> if (++i == 60)
> panic("can't schedule timer");
> - next_time = xen_fetch_vcpu_time() + first_in_ns;
> + critical_enter();
> + next_time = xen_fetch_vcpu_time(DPCPU_GET(vcpu_info)) +
> + first_in_ns;
> + critical_exit();
> error = xentimer_vcpu_start_timer(cpu, next_time);
> } while (error == -ETIME);
>
> --
> 1.7.7.5 (Apple Git-26)
>
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