From nobody Fri Dec 19 17:17:08 2025 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 DE24F26A1AF; Mon, 19 May 2025 08:33:20 +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=1747643602; cv=none; b=Hsr1tXk10z0avP/+cUnSk93P4niKJmXDM0CtMTrZ33TuYkWUY92mUo0LH3kN7mUlTtvSeGFDkz0HOGFaEyS7C68WYjARSalOCKgghp3y+G7EjUN15rXQGXNzHpVS/62QsQ0oSs3zSJjb7w7LkB6vIpIVUbl2onpEb/RRP0byJ4U= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1747643602; c=relaxed/simple; bh=Sx6rncooqkhKOzat2v2on7x2T8s4Z9UMGZUwfEwbSWE=; h=Message-ID:From:To:Cc:Subject:References:MIME-Version: Content-Type:Date; b=n4YvH1n1DLM65XuJbwC4EHkSZHwo6zVRPvKAQ2prJ4uOBEkyrtK/sfPKUmlJ0vy+j3+iC4v9rjSfpwJNG1oyd+WKY7Q2C8CrlZkjvvQCjxrDzeFG9RxLhMTCq+fKbih7lMNcB3ZHJLEa7yFzHGldgKAR7o35F1fD0+lZ8JH8s4k= 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=p/HtvDsb; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=ygLGRzFg; 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="p/HtvDsb"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="ygLGRzFg" Message-ID: <20250519083025.842476378@linutronix.de> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1747643599; 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: references:references; bh=3906OWgNj05DnYmkA1aciBB3X1N0MG0VN+Nbx7YbBLY=; b=p/HtvDsb27Py71nJos+HecxF56B6gdkErX21gDy8TcXL56d68Gj4X/Kiq9V3iaPcFPeUtK ejx1NQX/nlDfOBwypvDgd0gUdECOu6LNg2oPrVhcMDcqDu4aMXqkI7NaJYa+15+72gJsoE QBQGUnftOGAHUT/XuxFlREgCUhlGPWykepxqYahCnl9QJv+4Jg4IlQt1a5Dqw574HxmtFc 72LMQuXzJzO4BWZbu2psgW04p1CZW26ShcLNc9uWGz1tm/cYHPUV6bUcMaC6XzI5wW8IYt TPTIHeqSdUFtgZX34RbrPug5/SkPskX82z/aXF5THO6+MkaKt6sBWq/TZBtPVw== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1747643599; 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: references:references; bh=3906OWgNj05DnYmkA1aciBB3X1N0MG0VN+Nbx7YbBLY=; b=ygLGRzFgM/88PJRFPuOSRaxDi3MF+SQXqHf8px/QOkuhS2rc5EFOHv2oMj6EJdaDqe5pkX ANAA9BR2Wi8gopDw== From: Thomas Gleixner To: LKML Cc: netdev@vger.kernel.org, Richard Cochran , Christopher Hall , John Stultz , Frederic Weisbecker , Anna-Maria Behnsen , Miroslav Lichvar , Werner Abt , David Woodhouse , Stephen Boyd , =?UTF-8?q?Thomas=20Wei=C3=9Fschuh?= , Kurt Kanzenbach , Nam Cao , Antoine Tenart Subject: [patch V2 04/26] timekeeping: Introduce timekeeper ID References: <20250519082042.742926976@linutronix.de> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Date: Mon, 19 May 2025 10:33:19 +0200 (CEST) Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: Anna-Maria Behnsen As long as there is only a single timekeeper, there is no need to clarify which timekeeper is used. But with the upcoming reusage of the timekeeper infrastructure for auxiliary clock timekeepers, an ID is required to differentiate. Introduce an enum for timekeeper IDs, introduce a field in struct tk_data to store this timekeeper id and add also initialization. The id struct field is added at the end of the second cachline, as there is a 4 byte hole anyway. Signed-off-by: Anna-Maria Behnsen Signed-off-by: Thomas Gleixner Acked-by: John Stultz --- include/linux/timekeeper_internal.h | 14 +++++++++++++- kernel/time/timekeeping.c | 5 +++-- 2 files changed, 16 insertions(+), 3 deletions(-) --- --- a/include/linux/timekeeper_internal.h +++ b/include/linux/timekeeper_internal.h @@ -12,6 +12,16 @@ #include =20 /** + * timekeeper_ids - IDs for various time keepers in the kernel + * @TIMEKEEPER_CORE: The central core timekeeper managing system time + * @TIMEKEEPERS_MAX: The maximum number of timekeepers managed + */ +enum timekeeper_ids { + TIMEKEEPER_CORE, + TIMEKEEPERS_MAX, +}; + +/** * struct tk_read_base - base structure for timekeeping readout * @clock: Current clocksource used for timekeeping. * @mask: Bitmask for two's complement subtraction of non 64bit clocks @@ -52,6 +62,7 @@ struct tk_read_base { * @offs_boot: Offset clock monotonic -> clock boottime * @offs_tai: Offset clock monotonic -> clock tai * @coarse_nsec: The nanoseconds part for coarse time getters + * @id: The timekeeper ID * @tkr_raw: The readout base structure for CLOCK_MONOTONIC_RAW * @raw_sec: CLOCK_MONOTONIC_RAW time in seconds * @clock_was_set_seq: The sequence number of clock was set events @@ -101,7 +112,7 @@ struct tk_read_base { * which results in the following cacheline layout: * * 0: seqcount, tkr_mono - * 1: xtime_sec ... coarse_nsec + * 1: xtime_sec ... id * 2: tkr_raw, raw_sec * 3,4: Internal variables * @@ -123,6 +134,7 @@ struct timekeeper { ktime_t offs_boot; ktime_t offs_tai; u32 coarse_nsec; + enum timekeeper_ids id; =20 /* Cacheline 2: */ struct tk_read_base tkr_raw; --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -1663,10 +1663,11 @@ read_persistent_wall_and_boot_offset(str *boot_offset =3D ns_to_timespec64(local_clock()); } =20 -static __init void tkd_basic_setup(struct tk_data *tkd) +static __init void tkd_basic_setup(struct tk_data *tkd, enum timekeeper_id= s tk_id) { raw_spin_lock_init(&tkd->lock); seqcount_raw_spinlock_init(&tkd->seq, &tkd->lock); + tkd->timekeeper.id =3D tkd->shadow_timekeeper.id =3D tk_id; } =20 /* @@ -1696,7 +1697,7 @@ void __init timekeeping_init(void) struct timekeeper *tks =3D &tk_core.shadow_timekeeper; struct clocksource *clock; =20 - tkd_basic_setup(&tk_core); + tkd_basic_setup(&tk_core, TIMEKEEPER_CORE); =20 read_persistent_wall_and_boot_offset(&wall_time, &boot_offset); if (timespec64_valid_settod(&wall_time) &&