Date: Thu, 19 Dec 2013 19:54:42 +0100 From: Roger Pau Monne <roger.pau@citrix.com> To: <freebsd-xen@freebsd.org>, <freebsd-current@freebsd.org>, <xen-devel@lists.xen.org>, <gibbs@freebsd.org>, <jhb@freebsd.org>, <kib@freebsd.org>, <julien.grall@citrix.com> Cc: Roger Pau Monne <roger.pau@citrix.com> Subject: [PATCH v7 05/19] xen: rework xen timer so it can be used early in boot process Message-ID: <1387479296-33389-6-git-send-email-roger.pau@citrix.com> In-Reply-To: <1387479296-33389-1-git-send-email-roger.pau@citrix.com> References: <1387479296-33389-1-git-send-email-roger.pau@citrix.com>
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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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