[patch V2 51/64] timekeeping: Provide ktime_get_raw()

From: Thomas Gleixner
Date: Wed Jul 16 2014 - 17:09:49 EST


Provide a ktime_t based interface for raw monotonic time.

Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
---
include/linux/timekeeper_internal.h | 3 +++
include/linux/timekeeping.h | 6 ++++++
kernel/time/timekeeping.c | 25 +++++++++++++++++++++++++
3 files changed, 34 insertions(+)

Index: tip/include/linux/timekeeper_internal.h
===================================================================
--- tip.orig/include/linux/timekeeper_internal.h
+++ tip/include/linux/timekeeper_internal.h
@@ -54,6 +54,9 @@ struct timekeeper {
/* The current UTC to TAI offset in seconds */
s32 tai_offset;

+ /* Monotonic raw base time */
+ ktime_t base_raw;
+
/* The raw monotonic time for the CLOCK_MONOTONIC_RAW posix clock. */
struct timespec64 raw_time;

Index: tip/include/linux/timekeeping.h
===================================================================
--- tip.orig/include/linux/timekeeping.h
+++ tip/include/linux/timekeeping.h
@@ -107,6 +107,7 @@ enum tk_offsets {
extern ktime_t ktime_get(void);
extern ktime_t ktime_get_with_offset(enum tk_offsets offs);
extern ktime_t ktime_mono_to_any(ktime_t tmono, enum tk_offsets offs);
+extern ktime_t ktime_get_raw(void);

/**
* ktime_get_real - get the real (wall-) time in ktime_t format
@@ -158,6 +159,11 @@ static inline u64 ktime_get_boot_ns(void
return ktime_to_ns(ktime_get_boottime());
}

+static inline u64 ktime_get_raw_ns(void)
+{
+ return ktime_to_ns(ktime_get_raw());
+}
+
/*
* Timespec interfaces utilizing the ktime based ones
*/
Index: tip/kernel/time/timekeeping.c
===================================================================
--- tip.orig/kernel/time/timekeeping.c
+++ tip/kernel/time/timekeeping.c
@@ -305,6 +305,9 @@ static inline void tk_update_ktime_data(
nsec *= NSEC_PER_SEC;
nsec += tk->wall_to_monotonic.tv_nsec;
tk->base_mono = ns_to_ktime(nsec);
+
+ /* Update the monotonic raw base */
+ tk->base_raw = timespec64_to_ktime(tk->raw_time);
}

/* must hold timekeeper_lock */
@@ -467,6 +470,27 @@ ktime_t ktime_mono_to_any(ktime_t tmono,
EXPORT_SYMBOL_GPL(ktime_mono_to_any);

/**
+ * ktime_get_raw - Returns the raw monotonic time in ktime_t format
+ */
+ktime_t ktime_get_raw(void)
+{
+ struct timekeeper *tk = &tk_core.timekeeper;
+ unsigned int seq;
+ ktime_t base;
+ s64 nsecs;
+
+ do {
+ seq = read_seqcount_begin(&tk_core.seq);
+ base = tk->base_raw;
+ nsecs = timekeeping_get_ns_raw(tk);
+
+ } while (read_seqcount_retry(&tk_core.seq, seq));
+
+ return ktime_add_ns(base, nsecs);
+}
+EXPORT_SYMBOL_GPL(ktime_get_raw);
+
+/**
* ktime_get_ts64 - get the monotonic clock in timespec64 format
* @ts: pointer to timespec variable
*
@@ -878,6 +902,7 @@ void __init timekeeping_init(void)
tk_set_xtime(tk, &now);
tk->raw_time.tv_sec = 0;
tk->raw_time.tv_nsec = 0;
+ tk->base_raw.tv64 = 0;
if (boot.tv_sec == 0 && boot.tv_nsec == 0)
boot = tk_xtime(tk);



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