From patchwork Tue Sep 12 11:03:44 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tony Lindgren X-Patchwork-Id: 138145 Return-Path: Delivered-To: ouuuleilei@gmail.com Received: by 2002:a59:9ecd:0:b0:3f2:4152:657d with SMTP id t13csp371747vqx; Tue, 12 Sep 2023 05:32:50 -0700 (PDT) X-Google-Smtp-Source: AGHT+IEC4PQDxRASoA9k9poSUuUmXM3osNgTY0v3I7jgN5SyEvnocHLK11Y+xoR/j+42Z9Hmk+Um X-Received: by 2002:a05:6870:f116:b0:1c8:bfd1:ecb8 with SMTP id k22-20020a056870f11600b001c8bfd1ecb8mr15440505oac.30.1694521970237; Tue, 12 Sep 2023 05:32:50 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1694521970; cv=none; d=google.com; s=arc-20160816; b=Eq2OT4T/MlX0I+5q+6eMl1uK7DaUUUa6FNfBvigI7r0ivm8HW2i1coq5p055xiFJEh O2yJpKGv4EnpSrJ4ZdVX0dpeDq83qLFzN3FTJez1FhgiOSZ3h+vJrHTD+5Ie6B29gT5/ P0DA0gl7GsNOEUzbrLNnxHv2/YJAJse8dvieAQJbsC09JdICFq3jm5P1QowQJhKyAxUg ypsyAZboNM7hM6R5OLZr9AUJBZCT71lM92xIUH8fAwg+E2U0yb6lceyfDp+gI4CgIDy8 dN5gsUl1DakrReJcP1+rdiWMZI9fk6gG8mOAF4lDXCbFUDgwMLiK2+56fCooJ/fHonvY 3u3g== 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:from; bh=iGFmkklAH/4SpC7pzz/c0drG/5ssXAoE24bcpE+wVAw=; fh=n7dM+f7LjYuLx+o4gzxXNkEWC9u7qeJi6cmcRDZcVew=; b=cekX4F4n0JVT1IpkTIxdDhJQKfVx4E5srIeLO0/ZzX/YhrEsbwhi9rV6yjbkDlWfaO Xo6kLpBC8aMzAvkbCZ4/nYlur+aUh2+1D+0HlBw8btFfXIAYyRNLSJFOxi/wnglnko4C EAS6fPa9IIPW25t8B8QgFEd1y6ty/I51uOwif//2WB9cHIDGbmSKyU2VIwCqf5ZtDgRF 7qDGqXsxNG8MvcCa7QkyvFREBK11bNuHjjvJ7acuRi7fkoMAP9s8zBKVGVY342+QMVHJ ismtNyvVm/HMrEy5Oxk3ly82hh98W++cpFEdkKnQfy2Cr7NY1s19B24L1Yclcgil7cyJ 9DzA== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.31 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: from morse.vger.email (morse.vger.email. [23.128.96.31]) by mx.google.com with ESMTPS id i76-20020a636d4f000000b0056534300dc2si365498pgc.247.2023.09.12.05.32.45 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 12 Sep 2023 05:32:50 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.31 as permitted sender) client-ip=23.128.96.31; Authentication-Results: mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.31 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: from out1.vger.email (depot.vger.email [IPv6:2620:137:e000::3:0]) by morse.vger.email (Postfix) with ESMTP id 0708380A9E32; Tue, 12 Sep 2023 04:05:37 -0700 (PDT) X-Virus-Status: Clean X-Virus-Scanned: clamav-milter 0.103.8 at morse.vger.email Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234373AbjILLFA (ORCPT + 37 others); Tue, 12 Sep 2023 07:05:00 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39608 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233867AbjILLE0 (ORCPT ); Tue, 12 Sep 2023 07:04:26 -0400 Received: from muru.com (muru.com [72.249.23.125]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 94171B9; Tue, 12 Sep 2023 04:04:22 -0700 (PDT) Received: from hillo.muru.com (localhost [127.0.0.1]) by muru.com (Postfix) with ESMTP id 6587D80FC; Tue, 12 Sep 2023 11:04:20 +0000 (UTC) From: Tony Lindgren To: Greg Kroah-Hartman , Jiri Slaby Cc: Andy Shevchenko , Dhruva Gole , =?utf-8?q?Ilpo_J=C3=A4rvinen?= , John Ogness , Johan Hovold , Sebastian Andrzej Siewior , Vignesh Raghavendra , linux-kernel@vger.kernel.org, linux-serial@vger.kernel.org Subject: [PATCH v2 2/3] serial: core: Add support for DEVNAME:0.0 style naming for kernel console Date: Tue, 12 Sep 2023 14:03:44 +0300 Message-ID: <20230912110350.14482-3-tony@atomide.com> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20230912110350.14482-1-tony@atomide.com> References: <20230912110350.14482-1-tony@atomide.com> 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 (morse.vger.email [0.0.0.0]); Tue, 12 Sep 2023 04:05:37 -0700 (PDT) X-Spam-Status: No, score=-0.8 required=5.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, 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 morse.vger.email X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: 1776835069935933500 X-GMAIL-MSGID: 1776835069935933500 We can now add hardware based addressing to serial ports. Starting with commit 84a9582fd203 ("serial: core: Start managing serial controllers to enable runtime PM"), and all the related fixes to this commit, the serial core now knows to which serial port controller the ports are connected. The serial ports can be addressed with DEVNAME:0.0 style naming. The names are something like 00:04:0.0 for a serial port on qemu, and something like 2800000.serial:0.0 on platform device using systems like ARM64 for example. The DEVNAME is the unique serial port hardware controller device name, AKA the name for port->dev. The 0.0 are the serial core controller id and port id. Typically 0.0 are used for each controller and port instance unless the serial port hardware controller has multiple controllers or ports. Using DEVNAME:0.0 style naming actually solves two long term issues for addressing the serial ports: 1. According to Andy Shevchenko, using DEVNAME:0.0 style naming fixes an issue where depending on the BIOS settings, the kernel serial port ttyS instance number may change if HSUART is enabled 2. Device tree using architectures no longer necessarily need to specify aliases to find a specific serial port, and we can just allocate the ttyS instance numbers dynamically in whatever probe order To do this, we need a custom init time parser for the console= command line option as printk already handles parsing it with console_setup(). Also early_param() gets handled by console_setup() if "console" and "earlycon" are used. Signed-off-by: Tony Lindgren --- drivers/tty/serial/Makefile | 3 + drivers/tty/serial/serial_base.h | 11 +++ drivers/tty/serial/serial_base_con.c | 133 +++++++++++++++++++++++++++ drivers/tty/serial/serial_core.c | 4 + 4 files changed, 151 insertions(+) create mode 100644 drivers/tty/serial/serial_base_con.c diff --git a/drivers/tty/serial/Makefile b/drivers/tty/serial/Makefile --- a/drivers/tty/serial/Makefile +++ b/drivers/tty/serial/Makefile @@ -3,6 +3,9 @@ # Makefile for the kernel serial device drivers. # +# Parse kernel command line consoles before the serial drivers probe +obj-$(CONFIG_SERIAL_CORE_CONSOLE) += serial_base_con.o + obj-$(CONFIG_SERIAL_CORE) += serial_base.o serial_base-y := serial_core.o serial_base_bus.o serial_ctrl.o serial_port.o diff --git a/drivers/tty/serial/serial_base.h b/drivers/tty/serial/serial_base.h --- a/drivers/tty/serial/serial_base.h +++ b/drivers/tty/serial/serial_base.h @@ -45,3 +45,14 @@ void serial_ctrl_unregister_port(struct uart_driver *drv, struct uart_port *port int serial_core_register_port(struct uart_driver *drv, struct uart_port *port); void serial_core_unregister_port(struct uart_driver *drv, struct uart_port *port); + +#ifdef CONFIG_SERIAL_CORE_CONSOLE +int serial_base_add_preferred_console(struct uart_driver *drv, + struct uart_port *port); +#else +static inline int serial_base_add_preferred_console(struct uart_driver *drv, + struct uart_port *port) +{ + return 0; +} +#endif diff --git a/drivers/tty/serial/serial_base_con.c b/drivers/tty/serial/serial_base_con.c new file mode 100644 --- /dev/null +++ b/drivers/tty/serial/serial_base_con.c @@ -0,0 +1,133 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Serial base console options handling + * + * Copyright (C) 2023 Texas Instruments Incorporated - https://www.ti.com/ + * Author: Tony Lindgren + */ + +#include +#include +#include +#include +#include + +#include "serial_base.h" + +static LIST_HEAD(serial_base_consoles); + +struct serial_base_console { + struct list_head node; + char *name; + char *opt; +}; + +/* + * Adds a preferred console for a serial port if console=DEVNAME:0.0 + * style addressing is used for the kernel command line. Translates + * from DEVNAME:0.0 to port->dev_name such as ttyS. Duplicates are + * ignored by add_preferred_console(). + */ +int serial_base_add_preferred_console(struct uart_driver *drv, + struct uart_port *port) +{ + struct serial_base_console *entry; + char *port_match; + + port_match = kasprintf(GFP_KERNEL, "%s:%i.%i", dev_name(port->dev), + port->ctrl_id, port->port_id); + if (!port_match) + return -ENOMEM; + + list_for_each_entry(entry, &serial_base_consoles, node) { + if (!strcmp(port_match, entry->name)) { + add_preferred_console(drv->dev_name, port->line, + entry->opt); + break; + } + } + + kfree(port_match); + + return 0; +} +EXPORT_SYMBOL_GPL(serial_base_add_preferred_console); + +/* Adds a command line console to the list of consoles for driver probe time */ +static int __init serial_base_add_con(char *name, char *opt) +{ + struct serial_base_console *con; + + con = kzalloc(sizeof(*con), GFP_KERNEL); + if (!con) + return -ENOMEM; + + con->name = kstrdup(name, GFP_KERNEL); + if (!con->name) + goto free_con; + + if (opt) { + con->opt = kstrdup(opt, GFP_KERNEL); + if (!con->name) + goto free_name; + } + + list_add_tail(&con->node, &serial_base_consoles); + + return 0; + +free_name: + kfree(con->name); + +free_con: + kfree(con); + + return -ENOMEM; +} + +/* Parse console name and options */ +static int __init serial_base_parse_one(char *param, char *val, + const char *unused, void *arg) +{ + char *opt; + + if (strcmp(param, "console")) + return 0; + + if (!val) + return 0; + + opt = strchr(val, ','); + if (opt) { + opt[0] = '\0'; + opt++; + } + + if (!strlen(val)) + return 0; + + return serial_base_add_con(val, opt); +} + +/* + * The "console=" option is handled by console_setup() in printk. We can't use + * early_param() as do_early_param() checks for "console" and "earlycon" options + * so console_setup() potentially handles console also early. Use parse_args(). + */ +static int __init serial_base_opts_init(void) +{ + char *command_line; + + command_line = kstrdup(boot_command_line, GFP_KERNEL); + if (!command_line) + return -ENOMEM; + + parse_args("Setting serial core console", command_line, + NULL, 0, -1, -1, NULL, serial_base_parse_one); + + kfree(command_line); + + return 0; +} + +arch_initcall(serial_base_opts_init); diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c --- a/drivers/tty/serial/serial_core.c +++ b/drivers/tty/serial/serial_core.c @@ -3358,6 +3358,10 @@ int serial_core_register_port(struct uart_driver *drv, struct uart_port *port) if (ret) goto err_unregister_ctrl_dev; + ret = serial_base_add_preferred_console(drv, port); + if (ret) + goto err_unregister_port_dev; + ret = serial_core_add_one_port(drv, port); if (ret) goto err_unregister_port_dev;