timekeeping: Remove CONFIG_GENERIC_TIME_VSYSCALL_OLD

As of d4d1fc61eb38f (ia64: Update fsyscall gettime to use modern
vsyscall_update)the last user of CONFIG_GENERIC_TIME_VSYSCALL_OLD
have been updated, the legacy support for old-style vsyscall
implementations can be removed from the timekeeping code.

(Thanks again to Tony Luck for helping remove the last user!)

[jstultz: Commit message rework]

Signed-off-by: Miroslav Lichvar <mlichvar@redhat.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Stephen Boyd <stephen.boyd@linaro.org>
Link: https://lkml.kernel.org/r/1510613491-16695-1-git-send-email-john.stultz@linaro.org

diff --git a/include/linux/timekeeper_internal.h b/include/linux/timekeeper_internal.h
index 7e9011101cb08f674a5c2ba698be5f67367a464c..d315c3d6725c499bde572fa61ab5068007c0ba5d 100644 (file)
--- a/include/linux/timekeeper_internal.h
+++ b/include/linux/timekeeper_internal.h
@@ -136,13 +136,6 @@ struct timekeeper {
 extern void update_vsyscall(struct timekeeper *tk);
 extern void update_vsyscall_tz(void);
 
-#elif defined(CONFIG_GENERIC_TIME_VSYSCALL_OLD)
-
-extern void update_vsyscall_old(struct timespec *ts, struct timespec *wtm,
-                               struct clocksource *c, u32 mult,
-                               u64 cycle_last);
-extern void update_vsyscall_tz(void);
-
 #else
 
 static inline void update_vsyscall(struct timekeeper *tk)

diff --git a/kernel/time/Kconfig b/kernel/time/Kconfig
index d689a9557e170b9d89ddb7cb42e518a82d5851cb..e776fc8cc1df3bc6dd09e7722250f87f183fb5ef 100644 (file)
--- a/kernel/time/Kconfig
+++ b/kernel/time/Kconfig
@@ -21,10 +21,6 @@ config CLOCKSOURCE_VALIDATE_LAST_CYCLE
 config GENERIC_TIME_VSYSCALL
        bool
 
-# Timekeeping vsyscall support
-config GENERIC_TIME_VSYSCALL_OLD
-       bool
-
 # Old style timekeeping
 config ARCH_USES_GETTIMEOFFSET
        bool

diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index 198afa78bf69e425b8cc1b0dfed538467df12bf7..cd03317e7b57deaec813644758080f605490f446 100644 (file)
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -557,45 +557,6 @@ static void halt_fast_timekeeper(struct timekeeper *tk)
        update_fast_timekeeper(&tkr_dummy, &tk_fast_raw);
 }
 
-#ifdef CONFIG_GENERIC_TIME_VSYSCALL_OLD
-#warning Please contact your maintainers, as GENERIC_TIME_VSYSCALL_OLD compatibity will disappear soon.
-
-static inline void update_vsyscall(struct timekeeper *tk)
-{
-       struct timespec xt, wm;
-
-       xt = timespec64_to_timespec(tk_xtime(tk));
-       wm = timespec64_to_timespec(tk->wall_to_monotonic);
-       update_vsyscall_old(&xt, &wm, tk->tkr_mono.clock, tk->tkr_mono.mult,
-                           tk->tkr_mono.cycle_last);
-}
-
-static inline void old_vsyscall_fixup(struct timekeeper *tk)
-{
-       s64 remainder;
-
-       /*
-       * Store only full nanoseconds into xtime_nsec after rounding
-       * it up and add the remainder to the error difference.
-       * XXX - This is necessary to avoid small 1ns inconsistnecies caused
-       * by truncating the remainder in vsyscalls. However, it causes
-       * additional work to be done in timekeeping_adjust(). Once
-       * the vsyscall implementations are converted to use xtime_nsec
-       * (shifted nanoseconds), and CONFIG_GENERIC_TIME_VSYSCALL_OLD
-       * users are removed, this can be killed.
-       */
-       remainder = tk->tkr_mono.xtime_nsec & ((1ULL << tk->tkr_mono.shift) - 1);
-       if (remainder != 0) {
-               tk->tkr_mono.xtime_nsec -= remainder;
-               tk->tkr_mono.xtime_nsec += 1ULL << tk->tkr_mono.shift;
-               tk->ntp_error += remainder << tk->ntp_error_shift;
-               tk->ntp_error -= (1ULL << tk->tkr_mono.shift) << tk->ntp_error_shift;
-       }
-}
-#else
-#define old_vsyscall_fixup(tk)
-#endif
-
 static RAW_NOTIFIER_HEAD(pvclock_gtod_chain);
 
 static void update_pvclock_gtod(struct timekeeper *tk, bool was_set)
@@ -2163,12 +2124,6 @@ void update_wall_time(void)
        /* correct the clock when NTP error is too big */
        timekeeping_adjust(tk, offset);
 
-       /*
-        * XXX This can be killed once everyone converts
-        * to the new update_vsyscall.
-        */
-       old_vsyscall_fixup(tk);
-
        /*
         * Finally, make sure that after the rounding
         * xtime_nsec isn't larger than NSEC_PER_SEC