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authorThomas Gleixner <tglx@linutronix.de>2013-02-04 11:03:03 +0100
committerThomas Gleixner <tglx@linutronix.de>2013-02-04 11:03:03 +0100
commit90889a635a9b5488624bccce3ff6b2eec68c007b (patch)
tree8ddde1e04060bd65ca2aafb09b38066cb7d69b4d /kernel/time/timekeeping.c
parenta9037430c6c784165a940a90bcd29f886834c8e7 (diff)
parent6f16eebe1ff82176339a0439c98ebec9768b0ee2 (diff)
downloadlinaro-lsk-90889a635a9b5488624bccce3ff6b2eec68c007b.tar.gz
Merge branch 'fortglx/3.9/time' of git://git.linaro.org/people/jstultz/linux into timers/core
Trivial conflict in arch/x86/Kconfig Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'kernel/time/timekeeping.c')
-rw-r--r--kernel/time/timekeeping.c45
1 files changed, 35 insertions, 10 deletions
diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index cbc6acb0db3..1e35515a875 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -29,6 +29,9 @@ static struct timekeeper timekeeper;
/* flag for if timekeeping is suspended */
int __read_mostly timekeeping_suspended;
+/* Flag for if there is a persistent clock on this platform */
+bool __read_mostly persistent_clock_exist = false;
+
static inline void tk_normalize_xtime(struct timekeeper *tk)
{
while (tk->xtime_nsec >= ((u64)NSEC_PER_SEC << tk->shift)) {
@@ -264,19 +267,18 @@ static void timekeeping_forward_now(struct timekeeper *tk)
}
/**
- * getnstimeofday - Returns the time of day in a timespec
+ * __getnstimeofday - Returns the time of day in a timespec.
* @ts: pointer to the timespec to be set
*
- * Returns the time of day in a timespec.
+ * Updates the time of day in the timespec.
+ * Returns 0 on success, or -ve when suspended (timespec will be undefined).
*/
-void getnstimeofday(struct timespec *ts)
+int __getnstimeofday(struct timespec *ts)
{
struct timekeeper *tk = &timekeeper;
unsigned long seq;
s64 nsecs = 0;
- WARN_ON(timekeeping_suspended);
-
do {
seq = read_seqbegin(&tk->lock);
@@ -287,6 +289,26 @@ void getnstimeofday(struct timespec *ts)
ts->tv_nsec = 0;
timespec_add_ns(ts, nsecs);
+
+ /*
+ * Do not bail out early, in case there were callers still using
+ * the value, even in the face of the WARN_ON.
+ */
+ if (unlikely(timekeeping_suspended))
+ return -EAGAIN;
+ return 0;
+}
+EXPORT_SYMBOL(__getnstimeofday);
+
+/**
+ * getnstimeofday - Returns the time of day in a timespec.
+ * @ts: pointer to the timespec to be set
+ *
+ * Returns the time of day in a timespec (WARN if suspended).
+ */
+void getnstimeofday(struct timespec *ts)
+{
+ WARN_ON(__getnstimeofday(ts));
}
EXPORT_SYMBOL(getnstimeofday);
@@ -640,12 +662,14 @@ void __init timekeeping_init(void)
struct timespec now, boot, tmp;
read_persistent_clock(&now);
+
if (!timespec_valid_strict(&now)) {
pr_warn("WARNING: Persistent clock returned invalid value!\n"
" Check your CMOS/BIOS settings.\n");
now.tv_sec = 0;
now.tv_nsec = 0;
- }
+ } else if (now.tv_sec || now.tv_nsec)
+ persistent_clock_exist = true;
read_boot_clock(&boot);
if (!timespec_valid_strict(&boot)) {
@@ -718,11 +742,12 @@ void timekeeping_inject_sleeptime(struct timespec *delta)
{
struct timekeeper *tk = &timekeeper;
unsigned long flags;
- struct timespec ts;
- /* Make sure we don't set the clock twice */
- read_persistent_clock(&ts);
- if (!(ts.tv_sec == 0 && ts.tv_nsec == 0))
+ /*
+ * Make sure we don't set the clock twice, as timekeeping_resume()
+ * already did it
+ */
+ if (has_persistent_clock())
return;
write_seqlock_irqsave(&tk->lock, flags);