The following commit has been merged into the timers/core branch of tip:
Commit-ID: dbdcf8c4caeca8192daa43429ccf23a1feec126c
Gitweb: https://git.kernel.org/tip/dbdcf8c4caeca8192daa43429ccf23a1feec126c
Author: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
AuthorDate: Wed, 09 Oct 2024 10:29:01 +02:00
Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitterDate: Fri, 25 Oct 2024 19:49:13 +02:00
timekeeping: Encapsulate locking/unlocking of timekeeper_lock
timekeeper_lock protects updates of timekeeper (tk_core). It is also used
by vdso_update_begin/end() and not only internally by the timekeeper code.
As long as there is only a single timekeeper, this works fine. But when
the timekeeper infrastructure will be reused for per ptp clock timekeepers,
timekeeper_lock needs to be part of tk_core..
Therefore encapuslate locking/unlocking of timekeeper_lock and make the
lock static.
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Signed-off-by: Anna-Maria Behnsen <anna-maria@xxxxxxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Acked-by: John Stultz <jstultz@xxxxxxxxxx>
Link: https://lore.kernel.org/all/20241009-devel-anna-maria-b4-timers-ptp-timekeeping-v2-8-554456a44a15@xxxxxxxxxxxxx
---
kernel/time/timekeeping.c | 15 ++++++++++++++-
kernel/time/timekeeping_internal.h | 3 ++-
kernel/time/vsyscall.c | 5 ++---
3 files changed, 18 insertions(+), 5 deletions(-)
diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index 848d2b1..77e0a0f 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -41,7 +41,7 @@ enum timekeeping_adv_mode {
TK_ADV_FREQ
};
-DEFINE_RAW_SPINLOCK(timekeeper_lock);
+static DEFINE_RAW_SPINLOCK(timekeeper_lock);
/*
* The most important data for readout fits into a single 64 byte
@@ -114,6 +114,19 @@ static struct tk_fast tk_fast_raw ____cacheline_aligned = {
.base[1] = FAST_TK_INIT,
};
+unsigned long timekeeper_lock_irqsave(void)
+{
+ unsigned long flags;
+
+ raw_spin_lock_irqsave(&timekeeper_lock, flags);
+ return flags;
+}
+
+void timekeeper_unlock_irqrestore(unsigned long flags)
+{
+ raw_spin_unlock_irqrestore(&timekeeper_lock, flags);
+}
+
/*
* Multigrain timestamps require tracking the latest fine-grained timestamp
* that has been issued, and never returning a coarse-grained timestamp that is
diff --git a/kernel/time/timekeeping_internal.h b/kernel/time/timekeeping_internal.h
index 0bbae82..b3dca83 100644
--- a/kernel/time/timekeeping_internal.h
+++ b/kernel/time/timekeeping_internal.h
@@ -49,6 +49,7 @@ static inline u64 clocksource_delta(u64 now, u64 last, u64 mask)
#endif
/* Semi public for serialization of non timekeeper VDSO updates. */
-extern raw_spinlock_t timekeeper_lock;
+unsigned long timekeeper_lock_irqsave(void);
+void timekeeper_unlock_irqrestore(unsigned long flags);
#endif /* _TIMEKEEPING_INTERNAL_H */
diff --git a/kernel/time/vsyscall.c b/kernel/time/vsyscall.c
index 9193d61..98488b2 100644
--- a/kernel/time/vsyscall.c
+++ b/kernel/time/vsyscall.c
@@ -151,9 +151,8 @@ void update_vsyscall_tz(void)
unsigned long vdso_update_begin(void)
{
struct vdso_data *vdata = __arch_get_k_vdso_data();
- unsigned long flags;
+ unsigned long flags = timekeeper_lock_irqsave();
- raw_spin_lock_irqsave(&timekeeper_lock, flags);
vdso_write_begin(vdata);
return flags;
}
@@ -172,5 +171,5 @@ void vdso_update_end(unsigned long flags)
vdso_write_end(vdata);
__arch_sync_vdso_data(vdata);
- raw_spin_unlock_irqrestore(&timekeeper_lock, flags);
+ timekeeper_unlock_irqrestore(flags);
}
|