[PATCH 4/6][RFC] time: Introduce new GENERIC_TIME_VSYSCALL

From: John Stultz
Date: Mon Sep 17 2012 - 18:06:05 EST


Now that we moved everyone over to GENERIC_TIME_VSYSCALL_OLD,
introduce the new declaration and config option for the new
update_vsyscall method.

Cc: Tony Luck <tony.luck@xxxxxxxxx>
Cc: Paul Mackerras <paulus@xxxxxxxxx>
Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
Cc: Andy Lutomirski <luto@xxxxxxxxxxxxxx>
Cc: Martin Schwidefsky <schwidefsky@xxxxxxxxxx>
Cc: Paul Turner <pjt@xxxxxxxxxx>
Cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
Cc: Richard Cochran <richardcochran@xxxxxxxxx>
Cc: Prarit Bhargava <prarit@xxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Signed-off-by: John Stultz <john.stultz@xxxxxxxxxx>
---
include/linux/timekeeper_internal.h | 36 ++++++++++++++++++++++++++++-------
kernel/time/Kconfig | 4 ++++
kernel/time/timekeeping.c | 14 +-------------
3 files changed, 34 insertions(+), 20 deletions(-)

diff --git a/include/linux/timekeeper_internal.h b/include/linux/timekeeper_internal.h
index a904d76..8896471 100644
--- a/include/linux/timekeeper_internal.h
+++ b/include/linux/timekeeper_internal.h
@@ -66,16 +66,38 @@ struct timekeeper {
seqlock_t lock;
};

+static inline struct timespec tk_xtime(struct timekeeper *tk)
+{
+ struct timespec ts;
+
+ ts.tv_sec = tk->xtime_sec;
+ ts.tv_nsec = (long)(tk->xtime_nsec >> tk->shift);
+ return ts;
+}
+
+
+#ifdef CONFIG_GENERIC_TIME_VSYSCALL
+
+extern void update_vsyscall(struct timekeeper *tk);
+extern void update_vsyscall_tz(void);

-#ifdef CONFIG_GENERIC_TIME_VSYSCALL_OLD
-extern void
-update_vsyscall_old(struct timespec *ts, struct timespec *wtm,
- struct clocksource *c, u32 mult);
+#elif defined(CONFIG_GENERIC_TIME_VSYSCALL_OLD)
+
+extern void update_vsyscall_old(struct timespec *ts, struct timespec *wtm,
+ struct clocksource *c, u32 mult);
extern void update_vsyscall_tz(void);
+
+static inline void update_vsyscall(struct timekeeper *tk)
+{
+ struct timespec xt;
+
+ xt = tk_xtime(tk);
+ update_vsyscall_old(&xt, &tk->wall_to_monotonic, tk->clock, tk->mult);
+}
+
#else
-static inline void
-update_vsyscall_old(struct timespec *ts, struct timespec *wtm,
- struct clocksource *c, u32 mult)
+
+static inline void update_vsyscall(struct timekeeper *tk);
{
}
static inline void update_vsyscall_tz(void)
diff --git a/kernel/time/Kconfig b/kernel/time/Kconfig
index 489c861..8601f0d 100644
--- a/kernel/time/Kconfig
+++ b/kernel/time/Kconfig
@@ -13,6 +13,10 @@ config ARCH_CLOCKSOURCE_DATA
bool

# Timekeeping vsyscall support
+config GENERIC_TIME_VSYSCALL
+ bool
+
+# Timekeeping vsyscall support
config GENERIC_TIME_VSYSCALL_OLD
bool

diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index bdce688..61eaf3b 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -42,15 +42,6 @@ static inline void tk_normalize_xtime(struct timekeeper *tk)
}
}

-static struct timespec tk_xtime(struct timekeeper *tk)
-{
- struct timespec ts;
-
- ts.tv_sec = tk->xtime_sec;
- ts.tv_nsec = (long)(tk->xtime_nsec >> tk->shift);
- return ts;
-}
-
static void tk_set_xtime(struct timekeeper *tk, const struct timespec *ts)
{
tk->xtime_sec = ts->tv_sec;
@@ -192,14 +183,11 @@ static inline s64 timekeeping_get_ns_raw(struct timekeeper *tk)
/* must hold write on timekeeper.lock */
static void timekeeping_update(struct timekeeper *tk, bool clearntp)
{
- struct timespec xt;
-
if (clearntp) {
tk->ntp_error = 0;
ntp_clear();
}
- xt = tk_xtime(tk);
- update_vsyscall_old(&xt, &tk->wall_to_monotonic, tk->clock, tk->mult);
+ update_vsyscall(tk);
}

/**
--
1.7.9.5

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