From patchwork Thu Jun 20 12:45:27 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tony Lindgren X-Patchwork-Id: 808495 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.13]) (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 D2A0C1ACE73; Thu, 20 Jun 2024 12:46:25 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.175.65.13 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1718887587; cv=none; b=cr7Wn9UG1C9PtTIa+d9+B4WmZWgBYlDfR9tCtN8YuOaBXKxoJlu1ieK3fi/F5SyeS/+fekiZesdGikTfXWZcR0TDXNUjyARHlp+YPNvWf5Gnrd68ln3+kmzQj4kGWFezAuorGOBz+jwFazT1I2M9w42MblxaL6V7qBiDzIHqBvI= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1718887587; c=relaxed/simple; bh=Zfo5p2XS+UpBhCaGmUZEdR7V1ETFipCjP8W5TnHmIiw=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=YWFBtnt8FwYek1eTUoE+QiUhJKizNVDreOn+91ilDHf+osBsu42CYYzPT9AdQ76DxDZmfpv/T86Y281vHA7De5WJ8uPFVQClxcyvWQ7NJ/PDseYt7ht1VX+5r0TAx/Inms/JHc1XE7jFcY+B+ydHfrIbT9qrp7zpsiAmfYIOj4U= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com; spf=none smtp.mailfrom=linux.intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=f8jS/MB5; arc=none smtp.client-ip=198.175.65.13 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="f8jS/MB5" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1718887586; x=1750423586; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=Zfo5p2XS+UpBhCaGmUZEdR7V1ETFipCjP8W5TnHmIiw=; b=f8jS/MB5F+63hs8f+Z6Ln59kLLddnuT/f3Q1PXHmMU57Q+Z4YsPNsjVv az3VLG0y6YGDdlBbOhUQIzDD1oxWKMCU3YdR4HRDeoYAPn/f52f7Ab+xq tH/PoGiFluO9aG/hwq8zYC6+HM7ZGhRsnT+GFwPzvPFWZRWDD14sIpaoH hM57Jp2soFg58LDLDp1w6hm7WejMuiG8Fo90mBfLMJYkMuu32MALTEUmG nBHI9ISLJd1fCEBgXGKApO51YgDBlSPAXNtCkHfHp7CZ+VbO0dtfSbZFD 53EHQ+lVIXrCPqY0Q+bjNexCmC//gXdFkjQowTnxddvQZRpW6iMVKC7H2 A==; X-CSE-ConnectionGUID: HL/7htdlR9+jA+O/X/ou0g== X-CSE-MsgGUID: 1Kyt3dW6QD+qHMtPbS0Ddw== X-IronPort-AV: E=McAfee;i="6700,10204,11108"; a="26985670" X-IronPort-AV: E=Sophos;i="6.08,252,1712646000"; d="scan'208";a="26985670" Received: from orviesa008.jf.intel.com ([10.64.159.148]) by orvoesa105.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 20 Jun 2024 05:46:26 -0700 X-CSE-ConnectionGUID: nEKjr2BISbqmVdISbfwbLQ== X-CSE-MsgGUID: FBzR+O2JR9W573rVLTFEEw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.08,252,1712646000"; d="scan'208";a="42888676" Received: from ijarvine-desk1.ger.corp.intel.com (HELO tlindgre-MOBL1.intel.com) ([10.245.247.35]) by orviesa008-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 20 Jun 2024 05:46:21 -0700 From: Tony Lindgren To: Greg Kroah-Hartman , Jiri Slaby , Petr Mladek , Steven Rostedt , John Ogness , Sergey Senozhatsky , Tony Lindgren , Andy Shevchenko Cc: =?utf-8?q?Ilpo_J=C3=A4rvinen?= , linux-serial@vger.kernel.org, Tony Lindgren , linux-kernel@vger.kernel.org Subject: [PATCH v4 2/4] printk: Add match_devname_and_update_preferred_console() Date: Thu, 20 Jun 2024 15:45:27 +0300 Message-ID: <20240620124541.164931-3-tony.lindgren@linux.intel.com> X-Mailer: git-send-email 2.45.2 In-Reply-To: <20240620124541.164931-1-tony.lindgren@linux.intel.com> References: <20240620124541.164931-1-tony.lindgren@linux.intel.com> Precedence: bulk X-Mailing-List: linux-serial@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Let's add match_devname_and_update_preferred_console() for driver subsystems to call during init when the console is ready, and it's character device name is known. For now, we use it only for the serial layer to allow console=DEVNAME:0.0 style hardware based addressing for consoles. The earlier attempt on doing this caused a regression with the kernel command line console order as it added calling __add_preferred_console() again later on during init. A better approach was suggested by Petr where we add the deferred console to the console_cmdline[] and update it later on when the console is ready. Suggested-by: Petr Mladek Co-developed-by: Petr Mladek Reviewed-by: Petr Mladek Tested-by: Petr Mladek Signed-off-by: Tony Lindgren --- drivers/tty/serial/serial_base_bus.c | 8 ++- include/linux/printk.h | 4 ++ kernel/printk/console_cmdline.h | 1 + kernel/printk/printk.c | 103 +++++++++++++++++++++++---- 4 files changed, 100 insertions(+), 16 deletions(-) diff --git a/drivers/tty/serial/serial_base_bus.c b/drivers/tty/serial/serial_base_bus.c index 5ebacb982f9e..2cf86f1ff298 100644 --- a/drivers/tty/serial/serial_base_bus.c +++ b/drivers/tty/serial/serial_base_bus.c @@ -210,7 +210,13 @@ void serial_base_port_device_remove(struct serial_port_device *port_dev) static int serial_base_add_one_prefcon(const char *match, const char *dev_name, int port_id) { - return 0; + int ret; + + ret = match_devname_and_update_preferred_console(match, dev_name, port_id); + if (ret == -ENOENT) + return 0; + + return ret; } #ifdef __sparc__ diff --git a/include/linux/printk.h b/include/linux/printk.h index 65c5184470f1..7239976698e4 100644 --- a/include/linux/printk.h +++ b/include/linux/printk.h @@ -60,6 +60,10 @@ static inline const char *printk_skip_headers(const char *buffer) #define CONSOLE_LOGLEVEL_DEFAULT CONFIG_CONSOLE_LOGLEVEL_DEFAULT #define CONSOLE_LOGLEVEL_QUIET CONFIG_CONSOLE_LOGLEVEL_QUIET +int match_devname_and_update_preferred_console(const char *match, + const char *name, + const short idx); + extern int console_printk[]; #define console_loglevel (console_printk[0]) diff --git a/kernel/printk/console_cmdline.h b/kernel/printk/console_cmdline.h index 3ca74ad391d6..0ab573b6d4dc 100644 --- a/kernel/printk/console_cmdline.h +++ b/kernel/printk/console_cmdline.h @@ -6,6 +6,7 @@ struct console_cmdline { char name[16]; /* Name of the driver */ int index; /* Minor dev. to use */ + char devname[32]; /* DEVNAME:0.0 style device name */ bool user_specified; /* Specified by command line vs. platform */ char *options; /* Options for the driver */ #ifdef CONFIG_A11Y_BRAILLE_CONSOLE diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c index dddb15f48d59..7d91593f0ecf 100644 --- a/kernel/printk/printk.c +++ b/kernel/printk/printk.c @@ -2429,18 +2429,23 @@ static void set_user_specified(struct console_cmdline *c, bool user_specified) console_set_on_cmdline = 1; } -static int __add_preferred_console(const char *name, const short idx, char *options, +static int __add_preferred_console(const char *name, const short idx, + const char *devname, char *options, char *brl_options, bool user_specified) { struct console_cmdline *c; int i; + if (!name && !devname) + return -EINVAL; + /* * We use a signed short index for struct console for device drivers to * indicate a not yet assigned index or port. However, a negative index - * value is not valid for preferred console. + * value is not valid when the console name and index are defined on + * the command line. */ - if (idx < 0) + if (name && idx < 0) return -EINVAL; /* @@ -2448,9 +2453,10 @@ static int __add_preferred_console(const char *name, const short idx, char *opti * if we have a slot free. */ for (i = 0, c = console_cmdline; - i < MAX_CMDLINECONSOLES && c->name[0]; + i < MAX_CMDLINECONSOLES && (c->name[0] || c->devname[0]); i++, c++) { - if (strcmp(c->name, name) == 0 && c->index == idx) { + if ((name && strcmp(c->name, name) == 0 && c->index == idx) || + (devname && strcmp(c->devname, devname) == 0)) { if (!brl_options) preferred_console = i; set_user_specified(c, user_specified); @@ -2461,7 +2467,10 @@ static int __add_preferred_console(const char *name, const short idx, char *opti return -E2BIG; if (!brl_options) preferred_console = i; - strscpy(c->name, name, sizeof(c->name)); + if (name) + strscpy(c->name, name); + if (devname) + strscpy(c->devname, devname); c->options = options; set_user_specified(c, user_specified); braille_set_options(c, brl_options); @@ -2486,8 +2495,13 @@ __setup("console_msg_format=", console_msg_format_setup); */ static int __init console_setup(char *str) { - char buf[sizeof(console_cmdline[0].name) + 4]; /* 4 for "ttyS" */ - char *s, *options, *brl_options = NULL; + static_assert(sizeof(console_cmdline[0].devname) >= sizeof(console_cmdline[0].name) + 4); + char buf[sizeof(console_cmdline[0].devname)]; + char *brl_options = NULL; + char *ttyname = NULL; + char *devname = NULL; + char *options; + char *s; int idx; /* @@ -2496,17 +2510,23 @@ static int __init console_setup(char *str) * for exactly this purpose. */ if (str[0] == 0 || strcmp(str, "null") == 0) { - __add_preferred_console("ttynull", 0, NULL, NULL, true); + __add_preferred_console("ttynull", 0, NULL, NULL, NULL, true); return 1; } if (_braille_console_setup(&str, &brl_options)) return 1; + /* For a DEVNAME:0.0 style console the character device is unknown early */ + if (strchr(str, ':')) + devname = buf; + else + ttyname = buf; + /* * Decode str into name, index, options. */ - if (isdigit(str[0])) + if (ttyname && isdigit(str[0])) scnprintf(buf, sizeof(buf), "ttyS%s", str); else strscpy(buf, str); @@ -2523,12 +2543,18 @@ static int __init console_setup(char *str) #endif for (s = buf; *s; s++) - if (isdigit(*s) || *s == ',') + if ((ttyname && isdigit(*s)) || *s == ',') break; - idx = simple_strtoul(s, NULL, 10); + + /* @idx will get defined when devname matches. */ + if (devname) + idx = -1; + else + idx = simple_strtoul(s, NULL, 10); + *s = 0; - __add_preferred_console(buf, idx, options, brl_options, true); + __add_preferred_console(ttyname, idx, devname, options, brl_options, true); return 1; } __setup("console=", console_setup); @@ -2548,7 +2574,51 @@ __setup("console=", console_setup); */ int add_preferred_console(const char *name, const short idx, char *options) { - return __add_preferred_console(name, idx, options, NULL, false); + return __add_preferred_console(name, idx, NULL, options, NULL, false); +} + +/** + * match_devname_and_update_preferred_console - Update a preferred console + * when matching devname is found. + * @devname: DEVNAME:0.0 style device name + * @name: Name of the corresponding console driver, e.g. "ttyS" + * @idx: Console index, e.g. port number. + * + * The function checks whether a device with the given @devname is + * preferred via the console=DEVNAME:0.0 command line option. + * It fills the missing console driver name and console index + * so that a later register_console() call could find (match) + * and enable this device. + * + * It might be used when a driver subsystem initializes particular + * devices with already known DEVNAME:0.0 style names. And it + * could predict which console driver name and index this device + * would later get associated with. + * + * Return: 0 on success, negative error code on failure. + */ +int match_devname_and_update_preferred_console(const char *devname, + const char *name, + const short idx) +{ + struct console_cmdline *c = console_cmdline; + int i; + + if (!devname || !strlen(devname) || !name || !strlen(name) || idx < 0) + return -EINVAL; + + for (i = 0; i < MAX_CMDLINECONSOLES && (c->name[0] || c->devname[0]); + i++, c++) { + if (!strcmp(devname, c->devname)) { + pr_info("associate the preferred console \"%s\" with \"%s%d\"\n", + devname, name, idx); + strscpy(c->name, name); + c->index = idx; + return 0; + } + } + + return -ENOENT; } bool console_suspend_enabled = true; @@ -3318,8 +3388,11 @@ static int try_enable_preferred_console(struct console *newcon, int i, err; for (i = 0, c = console_cmdline; - i < MAX_CMDLINECONSOLES && c->name[0]; + i < MAX_CMDLINECONSOLES && (c->name[0] || c->devname[0]); i++, c++) { + /* Console not yet initialized? */ + if (!c->name[0]) + continue; if (c->user_specified != user_specified) continue; if (!newcon->match ||