Revert "printk: Save console options for add_preferred_console_match()"

This reverts commit f03e8c10.

Let's roll back all of the serial core and printk console changes that
went into 6.10-rc1 as there still are problems with them that need to be
sorted out.

Link: https://lore.kernel.org/r/ZnpRozsdw6zbjqze@tlindgre-MOBL1Reported-by: Petr Mladek <pmladek@suse.com>
Reported-by: Tony Lindgren <tony@atomide.com>
Cc: Jiri Slaby <jirislaby@kernel.org>
Cc: John Ogness <john.ogness@linutronix.de>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

include/linux/printk.h

@@ -60,9 +60,6 @@ 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 add_preferred_console_match(const char *match, const char *name,
-				const short idx);
-
 extern int console_printk[];
 
 #define console_loglevel (console_printk[0])

kernel/printk/Makefile

 # SPDX-License-Identifier: GPL-2.0-only
-obj-y	= printk.o conopt.o
+obj-y	= printk.o
 obj-$(CONFIG_PRINTK)	+= printk_safe.o nbcon.o
 obj-$(CONFIG_A11Y_BRAILLE_CONSOLE)	+= braille.o
 obj-$(CONFIG_PRINTK_INDEX)	+= index.o

kernel/printk/conopt.c

-// SPDX-License-Identifier: GPL-2.0
-/*
- * Kernel command line console options for hardware based addressing
- *
- * Copyright (C) 2023 Texas Instruments Incorporated - https://www.ti.com/
- * Author: Tony Lindgren <tony@atomide.com>
- */
-
-#include <linux/console.h>
-#include <linux/init.h>
-#include <linux/string.h>
-#include <linux/types.h>
-
-#include <asm/errno.h>
-
-#include "console_cmdline.h"
-
-/*
- * Allow longer DEVNAME:0.0 style console naming such as abcd0000.serial:0.0
- * in addition to the legacy ttyS0 style naming.
- */
-#define CONSOLE_NAME_MAX	32
-
-#define CONSOLE_OPT_MAX		16
-#define CONSOLE_BRL_OPT_MAX	16
-
-struct console_option {
-	char name[CONSOLE_NAME_MAX];
-	char opt[CONSOLE_OPT_MAX];
-	char brl_opt[CONSOLE_BRL_OPT_MAX];
-	u8 has_brl_opt:1;
-};
-
-/* Updated only at console_setup() time, no locking needed */
-static struct console_option conopt[MAX_CMDLINECONSOLES];
-
-/**
- * console_opt_save - Saves kernel command line console option for driver use
- * @str: Kernel command line console name and option
- * @brl_opt: Braille console options
- *
- * Saves a kernel command line console option for driver subsystems to use for
- * adding a preferred console during init. Called from console_setup() only.
- *
- * Return: 0 on success, negative error code on failure.
- */
-int __init console_opt_save(const char *str, const char *brl_opt)
-{
-	struct console_option *con;
-	size_t namelen, optlen;
-	const char *opt;
-	int i;
-
-	namelen = strcspn(str, ",");
-	if (namelen == 0 || namelen >= CONSOLE_NAME_MAX)
-		return -EINVAL;
-
-	opt = str + namelen;
-	if (*opt == ',')
-		opt++;
-
-	optlen = strlen(opt);
-	if (optlen >= CONSOLE_OPT_MAX)
-		return -EINVAL;
-
-	for (i = 0; i < MAX_CMDLINECONSOLES; i++) {
-		con = &conopt[i];
-
-		if (con->name[0]) {
-			if (!strncmp(str, con->name, namelen))
-				return 0;
-			continue;
-		}
-
-		/*
-		 * The name isn't terminated, only opt is. Empty opt is fine,
-		 * but brl_opt can be either empty or NULL. For more info, see
-		 * _braille_console_setup().
-		 */
-		strscpy(con->name, str, namelen + 1);
-		strscpy(con->opt, opt, CONSOLE_OPT_MAX);
-		if (brl_opt) {
-			strscpy(con->brl_opt, brl_opt, CONSOLE_BRL_OPT_MAX);
-			con->has_brl_opt = 1;
-		}
-
-		return 0;
-	}
-
-	return -ENOMEM;
-}
-
-static struct console_option *console_opt_find(const char *name)
-{
-	struct console_option *con;
-	int i;
-
-	for (i = 0; i < MAX_CMDLINECONSOLES; i++) {
-		con = &conopt[i];
-		if (!strcmp(name, con->name))
-			return con;
-	}
-
-	return NULL;
-}
-
-/**
- * add_preferred_console_match - Adds a preferred console if a match is found
- * @match: Expected console on kernel command line, such as console=DEVNAME:0.0
- * @name: Name of the console character device to add such as ttyS
- * @idx: Index for the console
- *
- * Allows driver subsystems to add a console after translating the command
- * line name to the character device name used for the console. Options are
- * added automatically based on the kernel command line. Duplicate preferred
- * consoles are ignored by __add_preferred_console().
- *
- * Return: 0 on success, negative error code on failure.
- */
-int add_preferred_console_match(const char *match, const char *name,
-				const short idx)
-{
-	struct console_option *con;
-	char *brl_opt = NULL;
-
-	if (!match || !strlen(match) || !name || !strlen(name) ||
-	    idx < 0)
-		return -EINVAL;
-
-	con = console_opt_find(match);
-	if (!con)
-		return -ENOENT;
-
-	/*
-	 * See __add_preferred_console(). It checks for NULL brl_options to set
-	 * the preferred_console flag. Empty brl_opt instead of NULL leads into
-	 * the preferred_console flag not set, and CON_CONSDEV not being set,
-	 * and the boot console won't get disabled at the end of console_setup().
-	 */
-	if (con->has_brl_opt)
-		brl_opt = con->brl_opt;
-
-	console_opt_add_preferred_console(name, idx, con->opt, brl_opt);
-
-	return 0;
-}

kernel/printk/console_cmdline.h

@@ -2,12 +2,6 @@
 #ifndef _CONSOLE_CMDLINE_H
 #define _CONSOLE_CMDLINE_H
 
-#define MAX_CMDLINECONSOLES 8
-
-int console_opt_save(const char *str, const char *brl_opt);
-int console_opt_add_preferred_console(const char *name, const short idx,
-				      char *options, char *brl_options);
-
 struct console_cmdline
 {
 	char	name[16];			/* Name of the driver	    */

kernel/printk/printk.c

@@ -383,6 +383,9 @@ static int console_locked;
 /*
  *	Array of consoles built from command line options (console=)
  */
+
+#define MAX_CMDLINECONSOLES 8
+
 static struct console_cmdline console_cmdline[MAX_CMDLINECONSOLES];
 
 static int preferred_console = -1;
@@ -2500,10 +2503,6 @@ static int __init console_setup(char *str)
 	if (_braille_console_setup(&str, &brl_options))
 		return 1;
 
-	/* Save the console for driver subsystem use */
-	if (console_opt_save(str, brl_options))
-		return 1;
-
 	/*
 	 * Decode str into name, index, options.
 	 */
@@ -2534,13 +2533,6 @@ static int __init console_setup(char *str)
 }
 __setup("console=", console_setup);
 
-/* Only called from add_preferred_console_match() */
-int console_opt_add_preferred_console(const char *name, const short idx,
-				      char *options, char *brl_options)
-{
-	return __add_preferred_console(name, idx, options, brl_options, true);
-}
-
 /**
  * add_preferred_console - add a device to the list of preferred consoles.
  * @name: device name