From patchwork Thu Sep 14 18:37:37 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: John Ogness X-Patchwork-Id: 139842 Return-Path: Delivered-To: ouuuleilei@gmail.com Received: by 2002:a05:612c:172:b0:3f2:4152:657d with SMTP id h50csp628883vqi; Thu, 14 Sep 2023 14:12:54 -0700 (PDT) X-Google-Smtp-Source: AGHT+IHjpcbQvJhtLQpzZyqGSLGM2Pj4bkwCWZYFPNo1u4HwLtjD7x6P7FuMqtQwO8crlAK+OlQX X-Received: by 2002:a17:903:110e:b0:1b8:8682:62fb with SMTP id n14-20020a170903110e00b001b8868262fbmr4042841plh.4.1694725973377; Thu, 14 Sep 2023 14:12:53 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1694725973; cv=none; d=google.com; s=arc-20160816; b=LHAdBJyfMSr0E9+dt4ZHTt/0z57Ix5d83J9DUfl4d957ZlfKTK6v1XxnbjLybeOMNL UOVf2ARtfuTp/VtwSZCUY2n8nmJemA5IPlxqB4Zw4NmZLR8/+56RDUEI4v9egFB8W2/b hP1aQfrSPFeUI+bgOuZMqkkKYWChpUSUh851TMbohnqfLGcsIwIlffIG47SGvePPfLj4 7Cwm+LBVy7VqZp0qpAiLLLqZJG73K5zJ+kxwFA1cnqTYJPU1LFGoZq/F9DGQ4bsP7wNT a0pFCHE1R6wDMtl3nNWvG6BtPCtQ2Xk7nQRjEY9swDTlwMVR3IEAbOzNYVoiPAxwEF0e +1CQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:content-transfer-encoding:mime-version :references:in-reply-to:message-id:date:subject:cc:to:dkim-signature :dkim-signature:from; bh=vzsn2wLYsWS44Gbs24avQ4nqhzEXcoHpcp6KNR2u0GE=; fh=+J7hVajEVCGVPf+nNqA1GQiFUy1T8lZxbpYqlyH+6OQ=; b=uWUMpL+Zb0Z+05D7W8jG/j/POd7CWiR7vOh8j3R2tFCEc6esMo8cblFbAnx3Rq59Gp CsLx+euD32qyubRDj296TSn+Wnz2OhLSM/8ETgNgsJiloDqSMc4WzL6et7rG22fCrHJ4 soFxkOJ0D0RqHlAR2b6MjwxoUQ0KFjUw0qb6Z2/UH9+ehxXn+Q9b0Ogj0qI+aoQp9IP9 nqOJFDvWMcpTH+/lo1JHY86sJew9u2sXVrcZGP3H+1XiLqN+k+PCu8i38uQlka3iHgKR TK+s7GBzCmmO2pC6/LPfS/Y00S3foL51UzZkuCn6kcadtb3hYblgg3VUsY+cPaquW5jp AFkg== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@linutronix.de header.s=2020 header.b=PiJR5jMN; dkim=neutral (no key) header.i=@linutronix.de header.s=2020e; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::3:6 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=QUARANTINE dis=NONE) header.from=linutronix.de Received: from pete.vger.email (pete.vger.email. [2620:137:e000::3:6]) by mx.google.com with ESMTPS id p15-20020a170902ebcf00b001bf0917df73si2079406plg.581.2023.09.14.14.12.52 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 14 Sep 2023 14:12:53 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::3:6 as permitted sender) client-ip=2620:137:e000::3:6; Authentication-Results: mx.google.com; dkim=pass header.i=@linutronix.de header.s=2020 header.b=PiJR5jMN; dkim=neutral (no key) header.i=@linutronix.de header.s=2020e; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::3:6 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=QUARANTINE dis=NONE) header.from=linutronix.de Received: from out1.vger.email (depot.vger.email [IPv6:2620:137:e000::3:0]) by pete.vger.email (Postfix) with ESMTP id 311CE81C2029; Thu, 14 Sep 2023 11:40:48 -0700 (PDT) X-Virus-Status: Clean X-Virus-Scanned: clamav-milter 0.103.10 at pete.vger.email Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241957AbjINSjh (ORCPT + 33 others); Thu, 14 Sep 2023 14:39:37 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37354 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241655AbjINSix (ORCPT ); Thu, 14 Sep 2023 14:38:53 -0400 Received: from galois.linutronix.de (Galois.linutronix.de [IPv6:2a0a:51c0:0:12e:550::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4F11E2107; Thu, 14 Sep 2023 11:38:48 -0700 (PDT) From: John Ogness DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1694716727; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=vzsn2wLYsWS44Gbs24avQ4nqhzEXcoHpcp6KNR2u0GE=; b=PiJR5jMN7CVVZo8siH35FwnJFoSDfXaB7ytFHSQkwHRaQ+jVGAS45QDRTXT05uk0ubuWUR ypRaqKU5MiNEmIar0/k6pnSjYR7UZoP3tLOl1SWRLlPtvMAvuA2EWhBaxYg2PPa7frbNrq iW0FlJ1UVo03/8eHUfNsbc5INW1VgtLIFpmHtgZ5vzGMJSZfkGO+MrxULFEJ34hYUJqKPP IWsAFHssQ38VQeZn6VIF6MBsLqdxCWEQdJe5UHPrRiZtnI9mkk0TMLw7XyDWxJNc8IVj9X wTdog0tqfcGozCm07toBOvFNKPAaLuWTD75SD+cXvZr7wlaBeU/4eQMmdGpITA== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1694716727; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=vzsn2wLYsWS44Gbs24avQ4nqhzEXcoHpcp6KNR2u0GE=; b=MiF9n5qv0YK7IdQjzTI3Kbo1xwtqPynXg98RvBsu+Hr3Twlm6rN65Op6DLiw2hKFzDWYz1 gBCFTmnSTbNPWfAw== To: Greg Kroah-Hartman Cc: Jiri Slaby , linux-serial@vger.kernel.org, Petr Mladek , Thomas Gleixner , linux-kernel@vger.kernel.org, Vineet Gupta , linux-snps-arc@lists.infradead.org Subject: [PATCH tty v1 20/74] serial: arc_uart: Use port lock wrappers Date: Thu, 14 Sep 2023 20:43:37 +0206 Message-Id: <20230914183831.587273-21-john.ogness@linutronix.de> In-Reply-To: <20230914183831.587273-1-john.ogness@linutronix.de> References: <20230914183831.587273-1-john.ogness@linutronix.de> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-Greylist: Sender passed SPF test, not delayed by milter-greylist-4.6.4 (pete.vger.email [0.0.0.0]); Thu, 14 Sep 2023 11:40:48 -0700 (PDT) X-Spam-Status: No, score=-0.2 required=5.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INVALID_DATE_TZ_ABSURD, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on pete.vger.email X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: 1777048982351389866 X-GMAIL-MSGID: 1777048982351389866 From: Thomas Gleixner 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. All modifications of UART registers are guarded by the UART port lock, which provides an obvious synchronization point with the console infrastructure. To avoid adding this functionality to all UART drivers, wrap the spin_[un]lock*() invocations for uart_port::lock into helper functions which just contain the spin_[un]lock*() invocations for now. In a subsequent step these helpers will gain the console synchronization mechanisms. Converted with coccinelle. No functional change. Signed-off-by: Thomas Gleixner --- drivers/tty/serial/arc_uart.c | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) diff --git a/drivers/tty/serial/arc_uart.c b/drivers/tty/serial/arc_uart.c index ad4ae19b6ce3..1aa5b2b49c26 100644 --- a/drivers/tty/serial/arc_uart.c +++ b/drivers/tty/serial/arc_uart.c @@ -279,9 +279,9 @@ static irqreturn_t arc_serial_isr(int irq, void *dev_id) if (status & RXIENB) { /* already in ISR, no need of xx_irqsave */ - spin_lock(&port->lock); + uart_port_lock(port); arc_serial_rx_chars(port, status); - spin_unlock(&port->lock); + uart_port_unlock(port); } if ((status & TXIENB) && (status & TXEMPTY)) { @@ -291,12 +291,12 @@ static irqreturn_t arc_serial_isr(int irq, void *dev_id) */ UART_TX_IRQ_DISABLE(port); - spin_lock(&port->lock); + uart_port_lock(port); if (!uart_tx_stopped(port)) arc_serial_tx_chars(port); - spin_unlock(&port->lock); + uart_port_unlock(port); } return IRQ_HANDLED; @@ -366,7 +366,7 @@ arc_serial_set_termios(struct uart_port *port, struct ktermios *new, uartl = hw_val & 0xFF; uarth = (hw_val >> 8) & 0xFF; - spin_lock_irqsave(&port->lock, flags); + uart_port_lock_irqsave(port, &flags); UART_ALL_IRQ_DISABLE(port); @@ -391,7 +391,7 @@ arc_serial_set_termios(struct uart_port *port, struct ktermios *new, uart_update_timeout(port, new->c_cflag, baud); - spin_unlock_irqrestore(&port->lock, flags); + uart_port_unlock_irqrestore(port, flags); } static const char *arc_serial_type(struct uart_port *port) @@ -521,9 +521,9 @@ static void arc_serial_console_write(struct console *co, const char *s, struct uart_port *port = &arc_uart_ports[co->index].port; unsigned long flags; - spin_lock_irqsave(&port->lock, flags); + uart_port_lock_irqsave(port, &flags); uart_console_write(port, s, count, arc_serial_console_putchar); - spin_unlock_irqrestore(&port->lock, flags); + uart_port_unlock_irqrestore(port, flags); } static struct console arc_console = {