From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 5AB13EED617 for ; Fri, 15 Sep 2023 16:32:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:Message-ID: In-Reply-To:Subject:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=h3Vu49M3C+lrcjVMoWe7U8m9UU2qV9gvJD86VXFjmQM=; b=0XdRY2g019jZOE +c5xwtHVFvanP4SgZmTf29RJkhUjdWD8K4Iwk4rF0sZbT4ISvGiFuHG1ApfNXwgVGDFwRw7f94tUk Eg9dnJYo54QisYTsKy/eme7gEIsCwjK83Fv2V1HqXKS2byG5wDdAqqpI4GC01AhBZaU6XCCW++wEC IJbdJ5COB1p/913TCq0wvnP7lTn/U5ds1KSNzDkI2wBgYhgmbrov73SV6KkjSm0td1RCiwQpEu973 AC54dNpytvGb6xSz5ItEsoRPKiGBFpPs5p3UFu9U7AkO1fPlpdh4ZLHGMDBf/FjMzx9hdMtjoQ4BE PI2kSUWfx4Q/7Mxv1Hyg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1qhBjc-00B3g6-2G; Fri, 15 Sep 2023 16:32:00 +0000 Received: from mgamail.intel.com ([192.55.52.120]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1qh4tT-00AEYX-0n; Fri, 15 Sep 2023 09:13:45 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1694769223; x=1726305223; h=date:from:to:cc:subject:in-reply-to:message-id: references:mime-version; bh=mry5V7nr5xa9zDtsfeoNxabJToApg0Wq8K46aPBD860=; b=K2aHuLgvaqRj0lpduW9Mx6B9mAX1LEv2kVgWLDQCAN960LP9xJ2hv0H9 JJmGx10iUoBgi1WEcu/kx1r9Qq8nJEuxqPPbws/qhcksmfKagtNpPYU2w q3LpPiPg75MbKJyzq158qscu2st3ZR2bluMdu/C0sJTPNRvNoT7vc32I8 ihL4wSOKdmyucrcxFa3Krf0jLi7jzj/rlW4J2y7TD83jgUTyJZc4BGabm hs9X8OIwmpRSOuPyQSmNWZwGwVV7Szs0oda+DBhVFDd+qot6HFS8BdTi1 FIrvRhXuQe2zuyt5CxyEsiOb6BduYzYlV7XkRAkOjLx522ChgzxTuXdHz Q==; X-IronPort-AV: E=McAfee;i="6600,9927,10833"; a="378120581" X-IronPort-AV: E=Sophos;i="6.02,148,1688454000"; d="scan'208";a="378120581" Received: from orsmga005.jf.intel.com ([10.7.209.41]) by fmsmga104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 15 Sep 2023 02:13:33 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10833"; a="918589081" X-IronPort-AV: E=Sophos;i="6.02,148,1688454000"; d="scan'208";a="918589081" Received: from srdoo-mobl1.ger.corp.intel.com ([10.252.38.99]) by orsmga005-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 15 Sep 2023 02:13:03 -0700 Date: Fri, 15 Sep 2023 12:12:58 +0300 (EEST) From: =?ISO-8859-15?Q?Ilpo_J=E4rvinen?= To: John Ogness Subject: Re: [PATCH tty v1 00/74] serial: wrappers for uart port lock In-Reply-To: <20230914183831.587273-1-john.ogness@linutronix.de> Message-ID: <1446dc6-5ab0-629-45c8-3b7d8c76367d@linux.intel.com> References: <20230914183831.587273-1-john.ogness@linutronix.de> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230915_021343_330722_A1FC01C9 X-CRM114-Status: GOOD ( 27.21 ) X-Mailman-Approved-At: Fri, 15 Sep 2023 09:31:59 -0700 X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Geert Uytterhoeven , Alim Akhtar , Peter Korsgaard , linux-stm32@st-md-mailman.stormreply.com, Karol Gugala , Jerome Brunet , linux-samsung-soc@vger.kernel.org, Kevin Hilman , Hugo Villeneuve , Christophe Leroy , Hammer Hsieh , Jiamei Xie , NXP Linux Team , Vineet Gupta , Thierry Reding , Petr Mladek , Arend van Spriel , Sascha Hauer , Nicholas Piggin , linux-unisoc@lists.infradead.org, Thomas Gleixner , Andrew Jeffery , Greg Kroah-Hartman , LKML , Richard Genoud , Pengutronix Kernel Team , Andrew Morton , "Maciej W. Rozycki" , Alexandre Belloni , linux-aspeed@lists.ozlabs.org, Laxman Dewangan , Dmitry Rokosov , Xiongfeng Wang , Matthias Schiffer , delisun , Fabio Estevam , Ruan Jinjie , Matthew Howell , Jonathan Hunter , Gabriel Somlo , Hongyu Xie , Tobias Klauser , Yangtao Li , Martin Blumenstingl , linux-arm-msm@vger.kernel.org, linux-actions@lists.infradead.org, Biju Das , linux-amlogic@lists.infradead.org, Michal Simek , Sherry Sun , Neil Armstrong , Chunyan Zhang , "David S. Miller" , Kumaravel Thiagarajan , Lukas Wunner , Sergey Organov , Mukesh Ojha , Maxime Coquelin , Michael Ellerman , =?ISO-8859-15?Q?Pali_Roh=E1r?= , Lino Sanfilippo , Tom Rix , Lorenzo Pieralisi , Al Cooper , Yuan Can , Isaac True , linux-tegra@vger.kernel.org, Jiri Slaby , Rob Herring , Florian Fainelli , Mateusz Holenko , Kevin Cernekee , Andy Shevchenko , Shenwei Wang , Broadcom internal kernel review list , Joel Stanley , Chen-Yu Tsai , =?ISO-8859-15?Q?Ilpo_J=E4rvinen?= , linux-snps-arc@lists.infradead.org, Patrice Chotard , Jacky Huang , Arnd Bergmann , =?ISO-8859-15?Q?Uwe_Kleine-K=F6nig?= , =?ISO-8859-15?Q?Jonathan_Neusch=E4fer?= , Vladimir Zapolskiy , Baolin Wang , Orson Zhai , Tharun Kumar P , Timur Tabi , Claudiu Beznea , Konrad Dybcio , Thierry Reding , Sudeep Holla , Shawn Guo , =?ISO-8859-15?Q?Andreas_F=E4rber?= , Baruch Siach , Valentin Caron , Tony Lindgren , Sebastian Andrzej Siewior , Liviu Dudau , Alexandre Torgue , sparclinux@vger.kernel.org, Shan-Chun Hung , linux-riscv@lists.infradead.org, Marek Vasut , Lech Perczak , Russell King , Nick Hu , Andy Gross , linux-serial , Lukas Bulwahn , Manivannan Sadhasivam , Johan Hovold , linux-mediatek@lists.infradead.org, Paul Walmsley , Matthias Brugger , Andy Shevchenko , AngeloGioacchino Del Regno , linux-arm-kernel@lists.infradead.org, Taichi Sugaya , Bjorn Andersson , Nicolas Ferre , Lucas Tanure , Andrew Davis , Krzysztof Kozlowski , Palmer Dabbelt , Takao Orito , linuxppc-dev@lists.ozlabs.org Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org On Thu, 14 Sep 2023, John Ogness wrote: > When a serial port is used for kernel console output, then all > modifications to the UART registers which are done from other contexts, > e.g. getty, termios, are interference points for the kernel console. > > So far this has been ignored and the printk output is based on the > principle of hope. The rework of the console infrastructure which aims to > support threaded and atomic consoles, requires to mark sections which > modify the UART registers as unsafe. This allows the atomic write function > to make informed decisions and eventually to restore operational state. It > also allows to prevent the regular UART code from modifying UART registers > while printk output is in progress. Hi John, Would this also be useful to enable printing to console while under port's lock (by postponing the output until the lock is released)? E.g., 8250_dw.c has had this commented out since the dawn on time: /* * FIXME: this deadlocks if port->lock is already held * dev_err(p->dev, "Couldn't set LCR to %d\n", value); */ -- i. > All modifications of UART registers are guarded by the UART port lock, > which provides an obvious synchronization point with the console > infrastructure. > > Provide and use wrapper functions for spin_[un]lock*(port->lock) > invocations so that the console mechanics can be applied later on at a > single place and does not require to copy the same logic all over the > drivers. > > Patch 1 adds the wrapper functions. > > Patches 2-74 switch all uart port locking call sites to use the new > wrappers. These patches were automatically generated using coccinelle. > The 2 used coccinelle scripts are included below and executed as > follows: > > $ spatch --sp-file uartlock-1.cocci $FILE > $ spatch --sp-file uartlock-2.cocci --recursive-includes $FILE > > This series brings no functional change. > > Patches 2-74 contain identical commit message bodies. Feel free to > fold them into a single commit if that seems more reasonable. > > Thomas Gleixner (74): > serial: core: Provide port lock wrappers > serial: core: Use lock wrappers > serial: 21285: Use port lock wrappers > serial: 8250_aspeed_vuart: Use port lock wrappers > serial: 8250_bcm7271: Use port lock wrappers > serial: 8250: Use port lock wrappers > serial: 8250_dma: Use port lock wrappers > serial: 8250_dw: Use port lock wrappers > serial: 8250_exar: Use port lock wrappers > serial: 8250_fsl: Use port lock wrappers > serial: 8250_mtk: Use port lock wrappers > serial: 8250_omap: Use port lock wrappers > serial: 8250_pci1xxxx: Use port lock wrappers > serial: altera_jtaguart: Use port lock wrappers > serial: altera_uart: Use port lock wrappers > serial: amba-pl010: Use port lock wrappers > serial: amba-pl011: Use port lock wrappers > serial: apb: Use port lock wrappers > serial: ar933x: Use port lock wrappers > serial: arc_uart: Use port lock wrappers > serial: atmel: Use port lock wrappers > serial: bcm63xx-uart: Use port lock wrappers > serial: cpm_uart: Use port lock wrappers > serial: digicolor: Use port lock wrappers > serial: dz: Use port lock wrappers > serial: linflexuart: Use port lock wrappers > serial: fsl_lpuart: Use port lock wrappers > serial: icom: Use port lock wrappers > serial: imx: Use port lock wrappers > serial: ip22zilog: Use port lock wrappers > serial: jsm: Use port lock wrappers > serial: liteuart: Use port lock wrappers > serial: lpc32xx_hs: Use port lock wrappers > serial: ma35d1: Use port lock wrappers > serial: mcf: Use port lock wrappers > serial: men_z135_uart: Use port lock wrappers > serial: meson: Use port lock wrappers > serial: milbeaut_usio: Use port lock wrappers > serial: mpc52xx: Use port lock wrappers > serial: mps2-uart: Use port lock wrappers > serial: msm: Use port lock wrappers > serial: mvebu-uart: Use port lock wrappers > serial: omap: Use port lock wrappers > serial: owl: Use port lock wrappers > serial: pch: Use port lock wrappers > serial: pic32: Use port lock wrappers > serial: pmac_zilog: Use port lock wrappers > serial: pxa: Use port lock wrappers > serial: qcom-geni: Use port lock wrappers > serial: rda: Use port lock wrappers > serial: rp2: Use port lock wrappers > serial: sa1100: Use port lock wrappers > serial: samsung_tty: Use port lock wrappers > serial: sb1250-duart: Use port lock wrappers > serial: sc16is7xx: Use port lock wrappers > serial: tegra: Use port lock wrappers > serial: core: Use port lock wrappers > serial: mctrl_gpio: Use port lock wrappers > serial: txx9: Use port lock wrappers > serial: sh-sci: Use port lock wrappers > serial: sifive: Use port lock wrappers > serial: sprd: Use port lock wrappers > serial: st-asc: Use port lock wrappers > serial: stm32: Use port lock wrappers > serial: sunhv: Use port lock wrappers > serial: sunplus-uart: Use port lock wrappers > serial: sunsab: Use port lock wrappers > serial: sunsu: Use port lock wrappers > serial: sunzilog: Use port lock wrappers > serial: timbuart: Use port lock wrappers > serial: uartlite: Use port lock wrappers > serial: ucc_uart: Use port lock wrappers > serial: vt8500: Use port lock wrappers > serial: xilinx_uartps: Use port lock wrappers > > drivers/tty/serial/21285.c | 8 +- > drivers/tty/serial/8250/8250_aspeed_vuart.c | 6 +- > drivers/tty/serial/8250/8250_bcm7271.c | 28 +++--- > drivers/tty/serial/8250/8250_core.c | 12 +-- > drivers/tty/serial/8250/8250_dma.c | 8 +- > drivers/tty/serial/8250/8250_dw.c | 8 +- > drivers/tty/serial/8250/8250_exar.c | 4 +- > drivers/tty/serial/8250/8250_fsl.c | 6 +- > drivers/tty/serial/8250/8250_mtk.c | 8 +- > drivers/tty/serial/8250/8250_omap.c | 52 +++++----- > drivers/tty/serial/8250/8250_pci1xxxx.c | 8 +- > drivers/tty/serial/8250/8250_port.c | 100 ++++++++++---------- > drivers/tty/serial/altera_jtaguart.c | 28 +++--- > drivers/tty/serial/altera_uart.c | 20 ++-- > drivers/tty/serial/amba-pl010.c | 20 ++-- > drivers/tty/serial/amba-pl011.c | 72 +++++++------- > drivers/tty/serial/apbuart.c | 8 +- > drivers/tty/serial/ar933x_uart.c | 26 ++--- > drivers/tty/serial/arc_uart.c | 16 ++-- > drivers/tty/serial/atmel_serial.c | 24 ++--- > drivers/tty/serial/bcm63xx_uart.c | 22 ++--- > drivers/tty/serial/cpm_uart.c | 8 +- > drivers/tty/serial/digicolor-usart.c | 18 ++-- > drivers/tty/serial/dz.c | 32 +++---- > drivers/tty/serial/fsl_linflexuart.c | 26 ++--- > drivers/tty/serial/fsl_lpuart.c | 88 ++++++++--------- > drivers/tty/serial/icom.c | 26 ++--- > drivers/tty/serial/imx.c | 84 ++++++++-------- > drivers/tty/serial/ip22zilog.c | 36 +++---- > drivers/tty/serial/jsm/jsm_neo.c | 4 +- > drivers/tty/serial/jsm/jsm_tty.c | 16 ++-- > drivers/tty/serial/liteuart.c | 20 ++-- > drivers/tty/serial/lpc32xx_hs.c | 26 ++--- > drivers/tty/serial/ma35d1_serial.c | 22 ++--- > drivers/tty/serial/mcf.c | 20 ++-- > drivers/tty/serial/men_z135_uart.c | 8 +- > drivers/tty/serial/meson_uart.c | 30 +++--- > drivers/tty/serial/milbeaut_usio.c | 16 ++-- > drivers/tty/serial/mpc52xx_uart.c | 12 +-- > drivers/tty/serial/mps2-uart.c | 16 ++-- > drivers/tty/serial/msm_serial.c | 38 ++++---- > drivers/tty/serial/mvebu-uart.c | 18 ++-- > drivers/tty/serial/omap-serial.c | 38 ++++---- > drivers/tty/serial/owl-uart.c | 26 ++--- > drivers/tty/serial/pch_uart.c | 10 +- > drivers/tty/serial/pic32_uart.c | 20 ++-- > drivers/tty/serial/pmac_zilog.c | 52 +++++----- > drivers/tty/serial/pxa.c | 30 +++--- > drivers/tty/serial/qcom_geni_serial.c | 8 +- > drivers/tty/serial/rda-uart.c | 34 +++---- > drivers/tty/serial/rp2.c | 20 ++-- > drivers/tty/serial/sa1100.c | 20 ++-- > drivers/tty/serial/samsung_tty.c | 50 +++++----- > drivers/tty/serial/sb1250-duart.c | 12 +-- > drivers/tty/serial/sc16is7xx.c | 40 ++++---- > drivers/tty/serial/serial-tegra.c | 32 +++---- > drivers/tty/serial/serial_core.c | 88 ++++++++--------- > drivers/tty/serial/serial_mctrl_gpio.c | 4 +- > drivers/tty/serial/serial_port.c | 4 +- > drivers/tty/serial/serial_txx9.c | 26 ++--- > drivers/tty/serial/sh-sci.c | 68 ++++++------- > drivers/tty/serial/sifive.c | 16 ++-- > drivers/tty/serial/sprd_serial.c | 30 +++--- > drivers/tty/serial/st-asc.c | 18 ++-- > drivers/tty/serial/stm32-usart.c | 38 ++++---- > drivers/tty/serial/sunhv.c | 28 +++--- > drivers/tty/serial/sunplus-uart.c | 26 ++--- > drivers/tty/serial/sunsab.c | 34 +++---- > drivers/tty/serial/sunsu.c | 46 ++++----- > drivers/tty/serial/sunzilog.c | 42 ++++---- > drivers/tty/serial/timbuart.c | 8 +- > drivers/tty/serial/uartlite.c | 18 ++-- > drivers/tty/serial/ucc_uart.c | 4 +- > drivers/tty/serial/vt8500_serial.c | 8 +- > drivers/tty/serial/xilinx_uartps.c | 56 +++++------ > include/linux/serial_core.h | 91 ++++++++++++++++-- > 76 files changed, 1086 insertions(+), 1007 deletions(-) > > > base-commit: 0bb80ecc33a8fb5a682236443c1e740d5c917d1d > _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv