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[23.128.96.35]) by mx.google.com with ESMTPS id ie18-20020a17090b401200b0026d0fa1c51esi2063132pjb.125.2023.09.14.12.13.37 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 14 Sep 2023 12:13:38 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.35 as permitted sender) client-ip=23.128.96.35; Authentication-Results: mx.google.com; dkim=pass header.i=@linutronix.de header.s=2020 header.b=OvnQvp6F; dkim=neutral (no key) header.i=@linutronix.de; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.35 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 groat.vger.email (Postfix) with ESMTP id 6F8A6836FFEA; Thu, 14 Sep 2023 11:40:53 -0700 (PDT) X-Virus-Status: Clean X-Virus-Scanned: clamav-milter 0.103.10 at groat.vger.email Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242016AbjINSkJ (ORCPT + 33 others); Thu, 14 Sep 2023 14:40:09 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37348 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241778AbjINSi7 (ORCPT ); Thu, 14 Sep 2023 14:38:59 -0400 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 148E8213A; Thu, 14 Sep 2023 11:38:53 -0700 (PDT) From: John Ogness DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1694716731; 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=UlpF/H9lKMDrxmXTuNUKsAvkYnpqtMAZIidKoYfk2m8=; b=OvnQvp6FrSEUwDayVfCSyaTaDBzuc0qDHdbES+H9OAPO6Ha87bRKvDnKy+aUS4pdZFLLmB jDxwD/L3qDChRCkKs0q+jzzmJmJZiwqpSy8A1vQM9uRhSkNw2idhoRuvvgsJxrK+wZx4QG XqxrNYbAK6u7sE1Tzcyz/LRQvnyD2tzuxG6rvJL6EQObHJpanuV55slsCsY84hl6Zyio/3 pQD3+PfXQ3qkNC9MvbiF4uH2PApwczoZNDT9+YaqQDJfAN6RMTd8Q0wfobK08utaA6SImc QzGgZlJy1nebH8t5hloy88cBPuR+IEjxhUWo45LfVr3WtSj7eG3UDcwTb/G12w== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1694716731; 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=UlpF/H9lKMDrxmXTuNUKsAvkYnpqtMAZIidKoYfk2m8=; b=NkoS64+YSQlVmh/kcYnHAvKRouOJW5bYLm3LDjq5+uZbRS0+LZRledqxXPhj4J2guP/ZOw dmliYWM9jDfA5hBA== To: Greg Kroah-Hartman Cc: Jiri Slaby , linux-serial@vger.kernel.org, Petr Mladek , Thomas Gleixner , linux-kernel@vger.kernel.org, Karol Gugala , Mateusz Holenko , Gabriel Somlo , Joel Stanley Subject: [PATCH tty v1 32/74] serial: liteuart: Use port lock wrappers Date: Thu, 14 Sep 2023 20:43:49 +0206 Message-Id: <20230914183831.587273-33-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 (groat.vger.email [0.0.0.0]); Thu, 14 Sep 2023 11:40:53 -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 groat.vger.email X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: 1777041479743409645 X-GMAIL-MSGID: 1777041479743409645 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 Acked-by: Gabriel Somlo --- drivers/tty/serial/liteuart.c | 20 ++++++++++---------- 1 file changed, 10 insertions(+), 10 deletions(-) diff --git a/drivers/tty/serial/liteuart.c b/drivers/tty/serial/liteuart.c index d881cdd2a58f..a25ab1efe38f 100644 --- a/drivers/tty/serial/liteuart.c +++ b/drivers/tty/serial/liteuart.c @@ -139,13 +139,13 @@ static irqreturn_t liteuart_interrupt(int irq, void *data) * if polling, the context would be "in_serving_softirq", so use * irq[save|restore] spin_lock variants to cover all possibilities */ - spin_lock_irqsave(&port->lock, flags); + uart_port_lock_irqsave(port, &flags); isr = litex_read8(port->membase + OFF_EV_PENDING) & uart->irq_reg; if (isr & EV_RX) liteuart_rx_chars(port); if (isr & EV_TX) liteuart_tx_chars(port); - spin_unlock_irqrestore(&port->lock, flags); + uart_port_unlock_irqrestore(port, flags); return IRQ_RETVAL(isr); } @@ -195,10 +195,10 @@ static int liteuart_startup(struct uart_port *port) } } - spin_lock_irqsave(&port->lock, flags); + uart_port_lock_irqsave(port, &flags); /* only enabling rx irqs during startup */ liteuart_update_irq_reg(port, true, EV_RX); - spin_unlock_irqrestore(&port->lock, flags); + uart_port_unlock_irqrestore(port, flags); if (!port->irq) { timer_setup(&uart->timer, liteuart_timer, 0); @@ -213,9 +213,9 @@ static void liteuart_shutdown(struct uart_port *port) struct liteuart_port *uart = to_liteuart_port(port); unsigned long flags; - spin_lock_irqsave(&port->lock, flags); + uart_port_lock_irqsave(port, &flags); liteuart_update_irq_reg(port, false, EV_RX | EV_TX); - spin_unlock_irqrestore(&port->lock, flags); + uart_port_unlock_irqrestore(port, flags); if (port->irq) free_irq(port->irq, port); @@ -229,13 +229,13 @@ static void liteuart_set_termios(struct uart_port *port, struct ktermios *new, unsigned int baud; unsigned long flags; - spin_lock_irqsave(&port->lock, flags); + uart_port_lock_irqsave(port, &flags); /* update baudrate */ baud = uart_get_baud_rate(port, new, old, 0, 460800); uart_update_timeout(port, new->c_cflag, baud); - spin_unlock_irqrestore(&port->lock, flags); + uart_port_unlock_irqrestore(port, flags); } static const char *liteuart_type(struct uart_port *port) @@ -382,9 +382,9 @@ static void liteuart_console_write(struct console *co, const char *s, uart = (struct liteuart_port *)xa_load(&liteuart_array, co->index); port = &uart->port; - spin_lock_irqsave(&port->lock, flags); + uart_port_lock_irqsave(port, &flags); uart_console_write(port, s, count, liteuart_putchar); - spin_unlock_irqrestore(&port->lock, flags); + uart_port_unlock_irqrestore(port, flags); } static int liteuart_console_setup(struct console *co, char *options)