timekeeping: Consolidate fast timekeeper

[ Upstream commit 90be8d6c1f91e1e5121c219726524c91b52bfc20 ]

Provide a inline function which replaces the copy & pasta.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20220415091921.072296632@linutronix.de
Stable-dep-of: 5c1806c41ce0 ("kcsan, seqlock: Support seqcount_latch_t")
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index ce3d1377cbc7ac99edd9d5a8c9ebd6a0777ba76e..7f755127bee414909da543a41d092a555c94d317 100644 (file)
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -431,6 +431,14 @@ static void update_fast_timekeeper(const struct tk_read_base *tkr,
        memcpy(base + 1, base, sizeof(*base));
 }
 
+static __always_inline u64 fast_tk_get_delta_ns(struct tk_read_base *tkr)
+{
+       u64 delta, cycles = tk_clock_read(tkr);
+
+       delta = clocksource_delta(cycles, tkr->cycle_last, tkr->mask);
+       return timekeeping_delta_to_ns(tkr, delta);
+}
+
 static __always_inline u64 __ktime_get_fast_ns(struct tk_fast *tkf)
 {
        struct tk_read_base *tkr;
@@ -441,12 +449,7 @@ static __always_inline u64 __ktime_get_fast_ns(struct tk_fast *tkf)
                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));
+               now += fast_tk_get_delta_ns(tkr);
        } while (read_seqcount_latch_retry(&tkf->seq, seq));
 
        return now;
@@ -545,10 +548,7 @@ static __always_inline u64 __ktime_get_real_fast(struct tk_fast *tkf, u64 *mono)
                tkr = tkf->base + (seq & 0x01);
                basem = ktime_to_ns(tkr->base);
                baser = ktime_to_ns(tkr->base_real);
-
-               delta = timekeeping_delta_to_ns(tkr,
-                               clocksource_delta(tk_clock_read(tkr),
-                               tkr->cycle_last, tkr->mask));
+               delta = fast_tk_get_delta_ns(tkr);
        } while (read_seqcount_latch_retry(&tkf->seq, seq));
 
        if (mono)