timekeeping: Add ktime_get_coarse_with_offset
I have run into a couple of drivers using current_kernel_time()
suffering from the y2038 problem, and they could be converted
to using ktime_t, but don't have interfaces that skip the nanosecond
calculation at the moment.
This introduces ktime_get_coarse_with_offset() as a simpler
variant of ktime_get_with_offset(), and adds wrappers for the
three time domains we support with the existing function.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Stephen Boyd <sboyd@kernel.org>
Cc: y2038@lists.linaro.org
Cc: John Stultz <john.stultz@linaro.org>
Link: https://lkml.kernel.org/r/20180427134016.2525989-5-arnd@arndb.de
diff --git a/include/linux/timekeeping.h b/include/linux/timekeeping.h
index 3ef9791..42f71f4 100644
--- a/include/linux/timekeeping.h
+++ b/include/linux/timekeeping.h
@@ -51,6 +51,7 @@ enum tk_offsets {
extern ktime_t ktime_get(void);
extern ktime_t ktime_get_with_offset(enum tk_offsets offs);
+extern ktime_t ktime_get_coarse_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);
extern u32 ktime_get_resolution_ns(void);
@@ -63,6 +64,11 @@ static inline ktime_t ktime_get_real(void)
return ktime_get_with_offset(TK_OFFS_REAL);
}
+static inline ktime_t ktime_get_coarse_real(void)
+{
+ return ktime_get_coarse_with_offset(TK_OFFS_REAL);
+}
+
/**
* ktime_get_boottime - Returns monotonic time since boot in ktime_t format
*
@@ -74,6 +80,11 @@ static inline ktime_t ktime_get_boottime(void)
return ktime_get_with_offset(TK_OFFS_BOOT);
}
+static inline ktime_t ktime_get_coarse_boottime(void)
+{
+ return ktime_get_coarse_with_offset(TK_OFFS_BOOT);
+}
+
/**
* ktime_get_clocktai - Returns the TAI time of day in ktime_t format
*/
@@ -82,6 +93,11 @@ static inline ktime_t ktime_get_clocktai(void)
return ktime_get_with_offset(TK_OFFS_TAI);
}
+static inline ktime_t ktime_get_coarse_clocktai(void)
+{
+ return ktime_get_coarse_with_offset(TK_OFFS_TAI);
+}
+
/**
* ktime_mono_to_real - Convert monotonic time to clock realtime
*/
diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index ed9b74ec9c0..4786df9 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -795,6 +795,25 @@ ktime_t ktime_get_with_offset(enum tk_offsets offs)
}
EXPORT_SYMBOL_GPL(ktime_get_with_offset);
+ktime_t ktime_get_coarse_with_offset(enum tk_offsets offs)
+{
+ struct timekeeper *tk = &tk_core.timekeeper;
+ unsigned int seq;
+ ktime_t base, *offset = offsets[offs];
+
+ WARN_ON(timekeeping_suspended);
+
+ do {
+ seq = read_seqcount_begin(&tk_core.seq);
+ base = ktime_add(tk->tkr_mono.base, *offset);
+
+ } while (read_seqcount_retry(&tk_core.seq, seq));
+
+ return base;
+
+}
+EXPORT_SYMBOL_GPL(ktime_get_coarse_with_offset);
+
/**
* ktime_mono_to_any() - convert mononotic time to any other time
* @tmono: time to convert.