From patchwork Wed Oct 9 08:29:02 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Anna-Maria Behnsen X-Patchwork-Id: 13827748 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 0FF8B18CC12; Wed, 9 Oct 2024 08:29:19 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=193.142.43.55 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728462563; cv=none; b=b2v92gOK8s8mtQ4OJIwMNDd5TMbHw+R1WB6ZHIvJ/oDg+bfJV/TrzzOq/Yz4FqNAdvUqnfqr0ZdiXKfIQZlguC6KjNUzCBcDlAap0Sz68R7DY3ODSufKgzNet89XA7sR5N+L9/mrENkXayPtkK8ToZTpF8JK8VwN2y/SxP/JjCI= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728462563; c=relaxed/simple; bh=/wCUxTAAWXiNlHlzBVt+2w+bdH0nbWdZeI/9VMfEVuE=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=pNKVajbe82S+x0hxk2zNxUBcCzJK0PEWa7sm511pRJtoAnbxYTfF6/2b98W0DvNyTFFX42vaAfXRHt/DQiSmOKZ97Yi5fPxBYleJToCXO2wr4rAgosUSyFrRml2kY1T3Tz8xKdVYpcIbjBz6MLHjaKMexIsDjhRHBjFNbIhkDro= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de; spf=pass smtp.mailfrom=linutronix.de; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=Pk4FSoIc; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=Hvf0W/3i; arc=none smtp.client-ip=193.142.43.55 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linutronix.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="Pk4FSoIc"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="Hvf0W/3i" From: Anna-Maria Behnsen DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1728462557; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=ljxaAp+nO21hPqn0BhGelNMq77OIs2w6b9yghI2F5cI=; b=Pk4FSoIcEIN18KvlsB4ht6qwo6s66lebAYDqPh49r7SVat9vZJ9nIDZz+bXH6GP35h/D7J d0ZumKnuEJ5iTHBs/euB3XyrEHj2dsz5tRosLchzT91zQ6gyCyf4ei2N4miXdhlisDRcVr aAdV3YnINU/AiMeq8TIjYiag5eUBzlpQRrQ9WuzAmIOZlYWD4fWk2CSyQsEfJL3OhDSNqJ WUKo7eFZ0AIbdq93SzJsI1exqqPPd6hXG2C0uWWl5dlkB9EGNqxVtnZoaX1qBb0cDgD/sr 0WtqLpm0nPk8bpQbim/acqGQWM3bnCaWBXhAyDOrhUfUbqJopCGTeUju+XAgVw== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1728462557; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=ljxaAp+nO21hPqn0BhGelNMq77OIs2w6b9yghI2F5cI=; b=Hvf0W/3iRMzzXYsTxwtNLa2q/n77HhKSS93VT8zoTc0nXyYa4ylh4pVrPlzHBTNFabfISl p3a5oSpSCpjBpCDQ== Date: Wed, 09 Oct 2024 10:29:02 +0200 Subject: [PATCH v2 09/25] timekeeping: Move timekeeper_lock into tk_core Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-Id: <20241009-devel-anna-maria-b4-timers-ptp-timekeeping-v2-9-554456a44a15@linutronix.de> References: <20241009-devel-anna-maria-b4-timers-ptp-timekeeping-v2-0-554456a44a15@linutronix.de> In-Reply-To: <20241009-devel-anna-maria-b4-timers-ptp-timekeeping-v2-0-554456a44a15@linutronix.de> To: John Stultz , Frederic Weisbecker , Thomas Gleixner Cc: linux-kernel@vger.kernel.org, netdev@vger.kernel.org, Miroslav Lichvar , Richard Cochran , Christopher S Hall , Anna-Maria Behnsen From: Anna-Maria Behnsen timekeeper_lock protects updates to struct tk_core but is not part of struct tk_core. As long as there is only a single timekeeper, this is not a problem. But when the timekeeper infrastructure will be reused for per ptp clock timekeepers, timekeeper_lock needs to be part of tk_core. Move the lock into tk_core, move initialisation of the lock and sequence counter into timekeeping_init() and update all users of timekeeper_lock. As this is touching all lock sites, convert them to use: guard(raw_spinlock_irqsave)(&tk_core.lock); instead of lock/unlock functions whenever possible. Suggested-by: Thomas Gleixner Signed-off-by: Anna-Maria Behnsen Acked-by: John Stultz --- kernel/time/timekeeping.c | 72 +++++++++++++++++++---------------------------- 1 file changed, 29 insertions(+), 43 deletions(-) diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index c69004936b29..8557d32e5e3d 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -41,8 +41,6 @@ enum timekeeping_adv_mode { TK_ADV_FREQ }; -static DEFINE_RAW_SPINLOCK(timekeeper_lock); - /* * The most important data for readout fits into a single 64 byte * cache line. @@ -51,10 +49,8 @@ static struct { seqcount_raw_spinlock_t seq; struct timekeeper timekeeper; struct timekeeper shadow_timekeeper; -} tk_core ____cacheline_aligned = { - .seq = SEQCNT_RAW_SPINLOCK_ZERO(tk_core.seq, &timekeeper_lock), -}; - + raw_spinlock_t lock; +} tk_core ____cacheline_aligned; /* flag for if timekeeping is suspended */ int __read_mostly timekeeping_suspended; @@ -118,13 +114,13 @@ unsigned long timekeeper_lock_irqsave(void) { unsigned long flags; - raw_spin_lock_irqsave(&timekeeper_lock, flags); + raw_spin_lock_irqsave(&tk_core.lock, flags); return flags; } void timekeeper_unlock_irqrestore(unsigned long flags) { - raw_spin_unlock_irqrestore(&timekeeper_lock, flags); + raw_spin_unlock_irqrestore(&tk_core.lock, flags); } static inline void tk_normalize_xtime(struct timekeeper *tk) @@ -197,7 +193,7 @@ static inline void tk_update_sleep_time(struct timekeeper *tk, ktime_t delta) * the tkr's clocksource may change between the read reference, and the * clock reference passed to the read function. This can cause crashes if * the wrong clocksource is passed to the wrong read function. - * This isn't necessary to use when holding the timekeeper_lock or doing + * This isn't necessary to use when holding the tk_core.lock or doing * a read of the fast-timekeeper tkrs (which is protected by its own locking * and update logic). */ @@ -689,13 +685,11 @@ static void update_pvclock_gtod(struct timekeeper *tk, bool was_set) int pvclock_gtod_register_notifier(struct notifier_block *nb) { struct timekeeper *tk = &tk_core.timekeeper; - unsigned long flags; int ret; - raw_spin_lock_irqsave(&timekeeper_lock, flags); + guard(raw_spinlock_irqsave)(&tk_core.lock); ret = raw_notifier_chain_register(&pvclock_gtod_chain, nb); update_pvclock_gtod(tk, true); - raw_spin_unlock_irqrestore(&timekeeper_lock, flags); return ret; } @@ -708,14 +702,8 @@ EXPORT_SYMBOL_GPL(pvclock_gtod_register_notifier); */ int pvclock_gtod_unregister_notifier(struct notifier_block *nb) { - unsigned long flags; - int ret; - - raw_spin_lock_irqsave(&timekeeper_lock, flags); - ret = raw_notifier_chain_unregister(&pvclock_gtod_chain, nb); - raw_spin_unlock_irqrestore(&timekeeper_lock, flags); - - return ret; + guard(raw_spinlock_irqsave)(&tk_core.lock); + return raw_notifier_chain_unregister(&pvclock_gtod_chain, nb); } EXPORT_SYMBOL_GPL(pvclock_gtod_unregister_notifier); @@ -763,7 +751,7 @@ static inline void tk_update_ktime_data(struct timekeeper *tk) tk->tkr_raw.base = ns_to_ktime(tk->raw_sec * NSEC_PER_SEC); } -/* must hold timekeeper_lock */ +/* must hold tk_core.lock */ static void timekeeping_update(struct timekeeper *tk, unsigned int action) { if (action & TK_CLEAR_NTP) { @@ -1460,7 +1448,7 @@ int do_settimeofday64(const struct timespec64 *ts) if (!timespec64_valid_settod(ts)) return -EINVAL; - raw_spin_lock_irqsave(&timekeeper_lock, flags); + raw_spin_lock_irqsave(&tk_core.lock, flags); write_seqcount_begin(&tk_core.seq); timekeeping_forward_now(tk); @@ -1480,7 +1468,7 @@ int do_settimeofday64(const struct timespec64 *ts) timekeeping_update(tk, TK_CLEAR_NTP | TK_MIRROR | TK_CLOCK_WAS_SET); write_seqcount_end(&tk_core.seq); - raw_spin_unlock_irqrestore(&timekeeper_lock, flags); + raw_spin_unlock_irqrestore(&tk_core.lock, flags); /* Signal hrtimers about time change */ clock_was_set(CLOCK_SET_WALL); @@ -1510,7 +1498,7 @@ static int timekeeping_inject_offset(const struct timespec64 *ts) if (ts->tv_nsec < 0 || ts->tv_nsec >= NSEC_PER_SEC) return -EINVAL; - raw_spin_lock_irqsave(&timekeeper_lock, flags); + raw_spin_lock_irqsave(&tk_core.lock, flags); write_seqcount_begin(&tk_core.seq); timekeeping_forward_now(tk); @@ -1530,7 +1518,7 @@ static int timekeeping_inject_offset(const struct timespec64 *ts) timekeeping_update(tk, TK_CLEAR_NTP | TK_MIRROR | TK_CLOCK_WAS_SET); write_seqcount_end(&tk_core.seq); - raw_spin_unlock_irqrestore(&timekeeper_lock, flags); + raw_spin_unlock_irqrestore(&tk_core.lock, flags); /* Signal hrtimers about time change */ clock_was_set(CLOCK_SET_WALL); @@ -1606,7 +1594,7 @@ static int change_clocksource(void *data) return 0; } - raw_spin_lock_irqsave(&timekeeper_lock, flags); + raw_spin_lock_irqsave(&tk_core.lock, flags); write_seqcount_begin(&tk_core.seq); timekeeping_forward_now(tk); @@ -1615,7 +1603,7 @@ static int change_clocksource(void *data) timekeeping_update(tk, TK_CLEAR_NTP | TK_MIRROR | TK_CLOCK_WAS_SET); write_seqcount_end(&tk_core.seq); - raw_spin_unlock_irqrestore(&timekeeper_lock, flags); + raw_spin_unlock_irqrestore(&tk_core.lock, flags); if (old) { if (old->disable) @@ -1770,7 +1758,9 @@ void __init timekeeping_init(void) struct timespec64 wall_time, boot_offset, wall_to_mono; struct timekeeper *tk = &tk_core.timekeeper; struct clocksource *clock; - unsigned long flags; + + raw_spin_lock_init(&tk_core.lock); + seqcount_raw_spinlock_init(&tk_core.seq, &tkd->lock); read_persistent_wall_and_boot_offset(&wall_time, &boot_offset); if (timespec64_valid_settod(&wall_time) && @@ -1790,7 +1780,7 @@ void __init timekeeping_init(void) */ wall_to_mono = timespec64_sub(boot_offset, wall_time); - raw_spin_lock_irqsave(&timekeeper_lock, flags); + guard(raw_spinlock_irqsave)(&tk_core.lock); write_seqcount_begin(&tk_core.seq); ntp_init(); @@ -1807,7 +1797,6 @@ void __init timekeeping_init(void) timekeeping_update(tk, TK_MIRROR | TK_CLOCK_WAS_SET); write_seqcount_end(&tk_core.seq); - raw_spin_unlock_irqrestore(&timekeeper_lock, flags); } /* time in seconds when suspend began for persistent clock */ @@ -1888,7 +1877,7 @@ void timekeeping_inject_sleeptime64(const struct timespec64 *delta) struct timekeeper *tk = &tk_core.timekeeper; unsigned long flags; - raw_spin_lock_irqsave(&timekeeper_lock, flags); + raw_spin_lock_irqsave(&tk_core.lock, flags); write_seqcount_begin(&tk_core.seq); suspend_timing_needed = false; @@ -1900,7 +1889,7 @@ void timekeeping_inject_sleeptime64(const struct timespec64 *delta) timekeeping_update(tk, TK_CLEAR_NTP | TK_MIRROR | TK_CLOCK_WAS_SET); write_seqcount_end(&tk_core.seq); - raw_spin_unlock_irqrestore(&timekeeper_lock, flags); + raw_spin_unlock_irqrestore(&tk_core.lock, flags); /* Signal hrtimers about time change */ clock_was_set(CLOCK_SET_WALL | CLOCK_SET_BOOT); @@ -1924,7 +1913,7 @@ void timekeeping_resume(void) clockevents_resume(); clocksource_resume(); - raw_spin_lock_irqsave(&timekeeper_lock, flags); + raw_spin_lock_irqsave(&tk_core.lock, flags); write_seqcount_begin(&tk_core.seq); /* @@ -1962,7 +1951,7 @@ void timekeeping_resume(void) timekeeping_suspended = 0; timekeeping_update(tk, TK_MIRROR | TK_CLOCK_WAS_SET); write_seqcount_end(&tk_core.seq); - raw_spin_unlock_irqrestore(&timekeeper_lock, flags); + raw_spin_unlock_irqrestore(&tk_core.lock, flags); touch_softlockup_watchdog(); @@ -1993,7 +1982,7 @@ int timekeeping_suspend(void) suspend_timing_needed = true; - raw_spin_lock_irqsave(&timekeeper_lock, flags); + raw_spin_lock_irqsave(&tk_core.lock, flags); write_seqcount_begin(&tk_core.seq); timekeeping_forward_now(tk); timekeeping_suspended = 1; @@ -2032,7 +2021,7 @@ int timekeeping_suspend(void) timekeeping_update(tk, TK_MIRROR); halt_fast_timekeeper(tk); write_seqcount_end(&tk_core.seq); - raw_spin_unlock_irqrestore(&timekeeper_lock, flags); + raw_spin_unlock_irqrestore(&tk_core.lock, flags); tick_suspend(); clocksource_suspend(); @@ -2292,7 +2281,7 @@ static bool timekeeping_advance(enum timekeeping_adv_mode mode) int shift = 0, maxshift; u64 offset; - guard(raw_spinlock_irqsave)(&timekeeper_lock); + guard(raw_spinlock_irqsave)(&tk_core.lock); /* Make sure we're fully resumed: */ if (unlikely(timekeeping_suspended)) @@ -2589,7 +2578,7 @@ int do_adjtimex(struct __kernel_timex *txc) ktime_get_real_ts64(&ts); add_device_randomness(&ts, sizeof(ts)); - raw_spin_lock_irqsave(&timekeeper_lock, flags); + raw_spin_lock_irqsave(&tk_core.lock, flags); write_seqcount_begin(&tk_core.seq); orig_tai = tai = tk->tai_offset; @@ -2604,7 +2593,7 @@ int do_adjtimex(struct __kernel_timex *txc) } write_seqcount_end(&tk_core.seq); - raw_spin_unlock_irqrestore(&timekeeper_lock, flags); + raw_spin_unlock_irqrestore(&tk_core.lock, flags); audit_ntp_log(&ad); @@ -2628,11 +2617,8 @@ int do_adjtimex(struct __kernel_timex *txc) */ void hardpps(const struct timespec64 *phase_ts, const struct timespec64 *raw_ts) { - unsigned long flags; - - raw_spin_lock_irqsave(&timekeeper_lock, flags); + guard(raw_spinlock_irqsave)(&tk_core.lock); __hardpps(phase_ts, raw_ts); - raw_spin_unlock_irqrestore(&timekeeper_lock, flags); } EXPORT_SYMBOL(hardpps); #endif /* CONFIG_NTP_PPS */