Module: xenomai-forge
Branch: master
Commit: f595f891b2637167c9a7e07ece111d114c4eb704
URL:
http://git.xenomai.org/?p=xenomai-forge.git;a=commit;h=f595f891b2637167c9a7e07ece111d114c4eb704
Author: Philippe Gerum <r...@xenomai.org>
Date: Mon Aug 5 16:27:27 2013 +0200
cobalt/posix, lib/cobalt: direct reading of CLOCK_REALTIME (no syscall)
At some point, we may use the time source CLOCK_HOST_REALTIME is based
on whenever available, for implementing Xenomai's core clock
XN_REALTIME mode.
---
include/cobalt/kernel/clock.h | 1 +
include/cobalt/uapi/kernel/vdso.h | 3 +++
kernel/cobalt/clock.c | 4 +++-
kernel/cobalt/sys.c | 2 ++
lib/cobalt/clock.c | 10 ++++++++--
testsuite/clocktest/clocktest.c | 12 ++++++++++++
6 files changed, 29 insertions(+), 3 deletions(-)
diff --git a/include/cobalt/kernel/clock.h b/include/cobalt/kernel/clock.h
index fbe74d9..945fb28 100644
--- a/include/cobalt/kernel/clock.h
+++ b/include/cobalt/kernel/clock.h
@@ -35,6 +35,7 @@ struct xnsched;
struct xntimerdata;
struct xnclock {
+ /** ns */
xnticks_t wallclock_offset;
/** ns */
xnticks_t resolution;
diff --git a/include/cobalt/uapi/kernel/vdso.h
b/include/cobalt/uapi/kernel/vdso.h
index a4c5d80..9146873 100644
--- a/include/cobalt/uapi/kernel/vdso.h
+++ b/include/cobalt/uapi/kernel/vdso.h
@@ -43,11 +43,14 @@ struct xnvdso {
/* XNVDSO_FEAT_HOST_REALTIME */
struct xnvdso_hostrt_data hostrt_data;
+ /* XNVDSO_FEAT_WALLCLOCK_OFFSET */
+ unsigned long long wallclock_offset;
};
/* For each shared feature, add a flag below. */
#define XNVDSO_FEAT_HOST_REALTIME 0x0000000000000001ULL
+#define XNVDSO_FEAT_WALLCLOCK_OFFSET 0x0000000000000002ULL
static inline int xnvdso_test_feature(struct xnvdso *vdso,
unsigned long long feature)
diff --git a/kernel/cobalt/clock.c b/kernel/cobalt/clock.c
index b189500..735b204 100644
--- a/kernel/cobalt/clock.c
+++ b/kernel/cobalt/clock.c
@@ -28,6 +28,7 @@
#include <cobalt/kernel/timer.h>
#include <cobalt/kernel/clock.h>
#include <cobalt/kernel/arith.h>
+#include <cobalt/kernel/vdso.h>
#include <asm/xenomai/calibration.h>
unsigned long nktimerlat;
@@ -288,7 +289,7 @@ static void adjust_clock_timers(struct xnclock *clock,
xnsticks_t delta)
*
* @param clock The clock to adjust.
*
- * @param delta The adjustment value expressed in raw clock ticks.
+ * @param delta The adjustment value expressed in nanoseconds.
*
* @note This routine must be entered nklock locked, interrupts off.
*
@@ -309,6 +310,7 @@ void xnclock_adjust(struct xnclock *clock, xnsticks_t delta)
xnticks_t now;
nkclock.wallclock_offset += delta;
+ nkvdso->wallclock_offset = nkclock.wallclock_offset;
now = xnclock_read_monotonic(clock) + nkclock.wallclock_offset;
adjust_clock_timers(clock, delta);
diff --git a/kernel/cobalt/sys.c b/kernel/cobalt/sys.c
index df6fc93..4003ac0 100644
--- a/kernel/cobalt/sys.c
+++ b/kernel/cobalt/sys.c
@@ -30,6 +30,7 @@
#include <cobalt/kernel/select.h>
#include <cobalt/kernel/shadow.h>
#include <cobalt/kernel/lock.h>
+#include <cobalt/kernel/vdso.h>
#include <cobalt/kernel/sys.h>
cpumask_t nkaffinity = CPU_MASK_ALL;
@@ -53,6 +54,7 @@ static int enable_timesource(void)
nkclock.wallclock_offset =
xnclock_get_host_time() - xnclock_read_monotonic(&nkclock);
+ nkvdso->wallclock_offset = nkclock.wallclock_offset;
for_each_realtime_cpu(cpu) {
htickval = xntimer_grab_hardware(cpu);
diff --git a/lib/cobalt/clock.c b/lib/cobalt/clock.c
index 28c63cd..680a622 100644
--- a/lib/cobalt/clock.c
+++ b/lib/cobalt/clock.c
@@ -43,7 +43,7 @@ COBALT_IMPL(int, clock_getres, (clockid_t clock_id, struct
timespec *tp))
return -1;
}
-static int __do_clock_host_realtime(struct timespec *ts, void *tzp)
+static int __do_clock_host_realtime(struct timespec *ts)
{
unsigned long long now, base, mask, cycle_delta;
struct xnvdso_hostrt_data *hostrt_data;
@@ -89,7 +89,7 @@ COBALT_IMPL(int, clock_gettime, (clockid_t clock_id, struct
timespec *tp))
switch (clock_id) {
case CLOCK_HOST_REALTIME:
- ret = __do_clock_host_realtime(tp, NULL);
+ ret = __do_clock_host_realtime(tp);
break;
case CLOCK_MONOTONIC:
case CLOCK_MONOTONIC_RAW:
@@ -97,6 +97,12 @@ COBALT_IMPL(int, clock_gettime, (clockid_t clock_id, struct
timespec *tp))
tp->tv_sec = cobalt_divrem_billion(ns, &rem);
tp->tv_nsec = rem;
return 0;
+ case CLOCK_REALTIME:
+ ns = cobalt_ticks_to_ns(__xn_rdtsc());
+ ns += vdso->wallclock_offset;
+ tp->tv_sec = cobalt_divrem_billion(ns, &rem);
+ tp->tv_nsec = rem;
+ return 0;
default:
ret = -XENOMAI_SKINCALL2(__cobalt_muxid,
sc_cobalt_clock_gettime,
diff --git a/testsuite/clocktest/clocktest.c b/testsuite/clocktest/clocktest.c
index 1ae704b..3a34998 100644
--- a/testsuite/clocktest/clocktest.c
+++ b/testsuite/clocktest/clocktest.c
@@ -109,6 +109,16 @@ static void show_hostrt_diagnostics(void)
printf("shift : %u\n\n", vdso->hostrt_data.shift);
}
+static void show_realtime_offset(void)
+{
+ if (!xnvdso_test_feature(vdso, XNVDSO_FEAT_HOST_REALTIME)) {
+ printf("XNVDSO_FEAT_WALLCLOCK_OFFSET not available\n");
+ return;
+ }
+
+ printf("Wallclock offset : %llu\n", vdso->wallclock_offset);
+}
+
static inline unsigned long long read_clock(clockid_t clock_id)
{
struct timespec ts;
@@ -120,6 +130,8 @@ static inline unsigned long long read_clock(clockid_t
clock_id)
clock_id);
if (clock_id == CLOCK_HOST_REALTIME)
show_hostrt_diagnostics();
+ else if (clock_id == CLOCK_REALTIME)
+ show_realtime_offset();
exit(-1);
}
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