timekeeping: Fix up function documentation for the NMI safe accessors

	memcpy(base + 1, base, sizeof(*base));

}

static __always_inline u64 __ktime_get_fast_ns(struct tk_fast *tkf)

{

	struct tk_read_base *tkr;

	unsigned int seq;

	u64 now;

	do {

		seq = raw_read_seqcount_latch(&tkf->seq);

		tkr = tkf->base + (seq & 0x01);

		now = ktime_to_ns(tkr->base);

		now += timekeeping_delta_to_ns(tkr,

				clocksource_delta(

					tk_clock_read(tkr),

					tkr->cycle_last,

					tkr->mask));

	} while (read_seqcount_latch_retry(&tkf->seq, seq));

	return now;

}

/**

 * ktime_get_mono_fast_ns - Fast NMI safe access to clock monotonic

 *

 *

 * So reader 6 will observe time going backwards versus reader 5.

 *

 * While other CPUs are likely to be able observe that, the only way

 * While other CPUs are likely to be able to observe that, the only way

 * for a CPU local observation is when an NMI hits in the middle of

 * the update. Timestamps taken from that NMI context might be ahead

 * of the following timestamps. Callers need to be aware of that and

 * deal with it.

 */

static __always_inline u64 __ktime_get_fast_ns(struct tk_fast *tkf)

{

	struct tk_read_base *tkr;

	unsigned int seq;

	u64 now;

	do {

		seq = raw_read_seqcount_latch(&tkf->seq);

		tkr = tkf->base + (seq & 0x01);

		now = ktime_to_ns(tkr->base);

		now += timekeeping_delta_to_ns(tkr,

				clocksource_delta(

					tk_clock_read(tkr),

					tkr->cycle_last,

					tkr->mask));

	} while (read_seqcount_latch_retry(&tkf->seq, seq));

	return now;

}

u64 ktime_get_mono_fast_ns(void)

{

	return __ktime_get_fast_ns(&tk_fast_mono);

}

EXPORT_SYMBOL_GPL(ktime_get_mono_fast_ns);

/**

 * ktime_get_raw_fast_ns - Fast NMI safe access to clock monotonic raw

 *

 * Contrary to ktime_get_mono_fast_ns() this is always correct because the

 * conversion factor is not affected by NTP/PTP correction.

 */

u64 ktime_get_raw_fast_ns(void)

{

	return __ktime_get_fast_ns(&tk_fast_raw);

 * (2) On 32-bit systems, the 64-bit boot offset (tk->offs_boot) may be

 * partially updated.  Since the tk->offs_boot update is a rare event, this

 * should be a rare occurrence which postprocessing should be able to handle.

 *

 * The caveats vs. timestamp ordering as documented for ktime_get_fast_ns()

 * apply as well.

 */

u64 notrace ktime_get_boot_fast_ns(void)

{

}

EXPORT_SYMBOL_GPL(ktime_get_boot_fast_ns);

/*

 * See comment for __ktime_get_fast_ns() vs. timestamp ordering

 */

static __always_inline u64 __ktime_get_real_fast(struct tk_fast *tkf, u64 *mono)

{

	struct tk_read_base *tkr;

/**

 * ktime_get_real_fast_ns: - NMI safe and fast access to clock realtime.

 *

 * See ktime_get_fast_ns() for documentation of the time stamp ordering.

 */

u64 ktime_get_real_fast_ns(void)

{