#include <linux/time.h>
#include <linux/tick.h>
#include <linux/stop_machine.h>
+#include <linux/pvclock_gtod.h>
static struct timekeeper timekeeper;
-/*
- * This read-write spinlock protects us from races in SMP while
- * playing with xtime.
- */
-__cacheline_aligned_in_smp DEFINE_SEQLOCK(xtime_lock);
-
/* flag for if timekeeping is suspended */
int __read_mostly timekeeping_suspended;
return nsec + arch_gettimeoffset();
}
+static RAW_NOTIFIER_HEAD(pvclock_gtod_chain);
+
+static void update_pvclock_gtod(struct timekeeper *tk)
+{
+ raw_notifier_call_chain(&pvclock_gtod_chain, 0, tk);
+}
+
+/**
+ * pvclock_gtod_register_notifier - register a pvclock timedata update listener
+ *
+ * Must hold write on timekeeper.lock
+ */
+int pvclock_gtod_register_notifier(struct notifier_block *nb)
+{
+ struct timekeeper *tk = &timekeeper;
+ unsigned long flags;
+ int ret;
+
+ write_seqlock_irqsave(&tk->lock, flags);
+ ret = raw_notifier_chain_register(&pvclock_gtod_chain, nb);
+ /* update timekeeping data */
+ update_pvclock_gtod(tk);
+ write_sequnlock_irqrestore(&tk->lock, flags);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(pvclock_gtod_register_notifier);
+
+/**
+ * pvclock_gtod_unregister_notifier - unregister a pvclock
+ * timedata update listener
+ *
+ * Must hold write on timekeeper.lock
+ */
+int pvclock_gtod_unregister_notifier(struct notifier_block *nb)
+{
+ struct timekeeper *tk = &timekeeper;
+ unsigned long flags;
+ int ret;
+
+ write_seqlock_irqsave(&tk->lock, flags);
+ ret = raw_notifier_chain_unregister(&pvclock_gtod_chain, nb);
+ write_sequnlock_irqrestore(&tk->lock, flags);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(pvclock_gtod_unregister_notifier);
+
/* must hold write on timekeeper.lock */
static void timekeeping_update(struct timekeeper *tk, bool clearntp)
{
ntp_clear();
}
update_vsyscall(tk);
+ update_pvclock_gtod(tk);
}
/**
}
/*
- * The 64-bit jiffies value is not atomic - you MUST NOT read it
- * without sampling the sequence number in xtime_lock.
- * jiffies is defined in the linker script...
+ * Must hold jiffies_lock
*/
void do_timer(unsigned long ticks)
{
*/
void xtime_update(unsigned long ticks)
{
- write_seqlock(&xtime_lock);
+ write_seqlock(&jiffies_lock);
do_timer(ticks);
- write_sequnlock(&xtime_lock);
+ write_sequnlock(&jiffies_lock);
}