arch/alpha/kernel/srm_env.c - nest-cam/v179/linux - Git at Google

 /*
  * srm_env.c - Access to SRM environment
  *             variables through linux' procfs
  *
  * (C) 2001,2002,2006 by Jan-Benedict Glaw <jbglaw@lug-owl.de>
  *
  * This driver is at all a modified version of Erik Mouw's
  * Documentation/DocBook/procfs_example.c, so: thank
  * you, Erik! He can be reached via email at
  * <J.A.K.Mouw@its.tudelft.nl>. It is based on an idea
  * provided by DEC^WCompaq^WIntel's "Jumpstart" CD. They
  * included a patch like this as well. Thanks for idea!
  *
  * This program is free software; you can redistribute
  * it and/or modify it under the terms of the GNU General
  * Public License version 2 as published by the Free Software
  * Foundation.
  *
  * This program is distributed in the hope that it will be
  * useful, but WITHOUT ANY WARRANTY; without even the implied
  * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
  * PURPOSE.  See the GNU General Public License for more
  * details.
  *
  * You should have received a copy of the GNU General Public
  * License along with this program; if not, write to the
  * Free Software Foundation, Inc., 59 Temple Place,
  * Suite 330, Boston, MA  02111-1307  USA
  *
  */

 #include <linux/kernel.h>
 #include <linux/gfp.h>
 #include <linux/module.h>
 #include <linux/init.h>
 #include <linux/proc_fs.h>
 #include <linux/seq_file.h>
 #include <asm/console.h>
 #include <asm/uaccess.h>
 #include <asm/machvec.h>

 #define BASE_DIR	"srm_environment"	/* Subdir in /proc/		*/
 #define NAMED_DIR	"named_variables"	/* Subdir for known variables	*/
 #define NUMBERED_DIR	"numbered_variables"	/* Subdir for all variables	*/
 #define VERSION		"0.0.6"			/* Module version		*/
 #define NAME		"srm_env"		/* Module name			*/

 MODULE_AUTHOR("Jan-Benedict Glaw <jbglaw@lug-owl.de>");
 MODULE_DESCRIPTION("Accessing Alpha SRM environment through procfs interface");
 MODULE_LICENSE("GPL");

 typedef struct _srm_env {
 	char			*name;
 	unsigned long		id;
 	struct proc_dir_entry	*proc_entry;
 } srm_env_t;

 static struct proc_dir_entry	*base_dir;
 static struct proc_dir_entry	*named_dir;
 static struct proc_dir_entry	*numbered_dir;
 static char			number[256][4];

 static srm_env_t	srm_named_entries[] = {
 	{ "auto_action",	ENV_AUTO_ACTION		},
 	{ "boot_dev",		ENV_BOOT_DEV		},
 	{ "bootdef_dev",	ENV_BOOTDEF_DEV		},
 	{ "booted_dev",		ENV_BOOTED_DEV		},
 	{ "boot_file",		ENV_BOOT_FILE		},
 	{ "booted_file",	ENV_BOOTED_FILE		},
 	{ "boot_osflags",	ENV_BOOT_OSFLAGS	},
 	{ "booted_osflags",	ENV_BOOTED_OSFLAGS	},
 	{ "boot_reset",		ENV_BOOT_RESET		},
 	{ "dump_dev",		ENV_DUMP_DEV		},
 	{ "enable_audit",	ENV_ENABLE_AUDIT	},
 	{ "license",		ENV_LICENSE		},
 	{ "char_set",		ENV_CHAR_SET		},
 	{ "language",		ENV_LANGUAGE		},
 	{ "tty_dev",		ENV_TTY_DEV		},
 	{ NULL,			0			},
 };
 static srm_env_t	srm_numbered_entries[256];


 static int srm_env_proc_show(struct seq_file *m, void *v)
 {
 	unsigned long	ret;
 	srm_env_t	*entry;
 	char		*page;

 	entry = m->private;
 	page = (char *)__get_free_page(GFP_USER);
 	if (!page)
 		return -ENOMEM;

 	ret = callback_getenv(entry->id, page, PAGE_SIZE);

 	if ((ret >> 61) == 0) {
 		seq_write(m, page, ret);
 		ret = 0;
 	} else
 		ret = -EFAULT;
 	free_page((unsigned long)page);
 	return ret;
 }

 static int srm_env_proc_open(struct inode *inode, struct file *file)
 {
 	return single_open(file, srm_env_proc_show, PDE(inode)->data);
 }

 static ssize_t srm_env_proc_write(struct file *file, const char __user *buffer,
 				  size_t count, loff_t *pos)
 {
 	int res;
 	srm_env_t	*entry = PDE(file->f_path.dentry->d_inode)->data;
 	char		*buf = (char *) __get_free_page(GFP_USER);
 	unsigned long	ret1, ret2;

 	if (!buf)
 		return -ENOMEM;

 	res = -EINVAL;
 	if (count >= PAGE_SIZE)
 		goto out;

 	res = -EFAULT;
 	if (copy_from_user(buf, buffer, count))
 		goto out;
 	buf[count] = '\0';

 	ret1 = callback_setenv(entry->id, buf, count);
 	if ((ret1 >> 61) == 0) {
 		do
 			ret2 = callback_save_env();
 		while((ret2 >> 61) == 1);
 		res = (int) ret1;
 	}

  out:
 	free_page((unsigned long)buf);
 	return res;
 }

 static const struct file_operations srm_env_proc_fops = {
 	.owner		= THIS_MODULE,
 	.open		= srm_env_proc_open,
 	.read		= seq_read,
 	.llseek		= seq_lseek,
 	.release	= single_release,
 	.write		= srm_env_proc_write,
 };

 static void
 srm_env_cleanup(void)
 {
 	srm_env_t	*entry;
 	unsigned long	var_num;

 	if (base_dir) {
 		/*
 		 * Remove named entries
 		 */
 		if (named_dir) {
 			entry = srm_named_entries;
 			while (entry->name != NULL && entry->id != 0) {
 				if (entry->proc_entry) {
 					remove_proc_entry(entry->name,
 							named_dir);
 					entry->proc_entry = NULL;
 				}
 				entry++;
 			}
 			remove_proc_entry(NAMED_DIR, base_dir);
 		}

 		/*
 		 * Remove numbered entries
 		 */
 		if (numbered_dir) {
 			for (var_num = 0; var_num <= 255; var_num++) {
 				entry =	&srm_numbered_entries[var_num];

 				if (entry->proc_entry) {
 					remove_proc_entry(entry->name,
 							numbered_dir);
 					entry->proc_entry	= NULL;
 					entry->name		= NULL;
 				}
 			}
 			remove_proc_entry(NUMBERED_DIR, base_dir);
 		}

 		remove_proc_entry(BASE_DIR, NULL);
 	}

 	return;
 }

 static int __init
 srm_env_init(void)
 {
 	srm_env_t	*entry;
 	unsigned long	var_num;

 	/*
 	 * Check system
 	 */
 	if (!alpha_using_srm) {
 		printk(KERN_INFO "%s: This Alpha system doesn't "
 				"know about SRM (or you've booted "
 				"SRM->MILO->Linux, which gets "
 				"misdetected)...\n", __func__);
 		return -ENODEV;
 	}

 	/*
 	 * Init numbers
 	 */
 	for (var_num = 0; var_num <= 255; var_num++)
 		sprintf(number[var_num], "%ld", var_num);

 	/*
 	 * Create base directory
 	 */
 	base_dir = proc_mkdir(BASE_DIR, NULL);
 	if (!base_dir) {
 		printk(KERN_ERR "Couldn't create base dir /proc/%s\n",
 				BASE_DIR);
 		goto cleanup;
 	}

 	/*
 	 * Create per-name subdirectory
 	 */
 	named_dir = proc_mkdir(NAMED_DIR, base_dir);
 	if (!named_dir) {
 		printk(KERN_ERR "Couldn't create dir /proc/%s/%s\n",
 				BASE_DIR, NAMED_DIR);
 		goto cleanup;
 	}

 	/*
 	 * Create per-number subdirectory
 	 */
 	numbered_dir = proc_mkdir(NUMBERED_DIR, base_dir);
 	if (!numbered_dir) {
 		printk(KERN_ERR "Couldn't create dir /proc/%s/%s\n",
 				BASE_DIR, NUMBERED_DIR);
 		goto cleanup;

 	}

 	/*
 	 * Create all named nodes
 	 */
 	entry = srm_named_entries;
 	while (entry->name && entry->id) {
 		entry->proc_entry = proc_create_data(entry->name, 0644, named_dir,
 						     &srm_env_proc_fops, entry);
 		if (!entry->proc_entry)
 			goto cleanup;
 		entry++;
 	}

 	/*
 	 * Create all numbered nodes
 	 */
 	for (var_num = 0; var_num <= 255; var_num++) {
 		entry = &srm_numbered_entries[var_num];
 		entry->name = number[var_num];

 		entry->proc_entry = proc_create_data(entry->name, 0644, numbered_dir,
 						     &srm_env_proc_fops, entry);
 		if (!entry->proc_entry)
 			goto cleanup;

 		entry->id			= var_num;
 	}

 	printk(KERN_INFO "%s: version %s loaded successfully\n", NAME,
 			VERSION);

 	return 0;

 cleanup:
 	srm_env_cleanup();

 	return -ENOMEM;
 }

 static void __exit
 srm_env_exit(void)
 {
 	srm_env_cleanup();
 	printk(KERN_INFO "%s: unloaded successfully\n", NAME);

 	return;
 }

 module_init(srm_env_init);
 module_exit(srm_env_exit);
	/*
	* srm_env.c - Access to SRM environment
	* variables through linux' procfs
	*
	* (C) 2001,2002,2006 by Jan-Benedict Glaw <jbglaw@lug-owl.de>
	*
	* This driver is at all a modified version of Erik Mouw's
	* Documentation/DocBook/procfs_example.c, so: thank
	* you, Erik! He can be reached via email at
	* <J.A.K.Mouw@its.tudelft.nl>. It is based on an idea
	* provided by DEC^WCompaq^WIntel's "Jumpstart" CD. They
	* included a patch like this as well. Thanks for idea!
	*
	* This program is free software; you can redistribute
	* it and/or modify it under the terms of the GNU General
	* Public License version 2 as published by the Free Software
	* Foundation.
	*
	* This program is distributed in the hope that it will be
	* useful, but WITHOUT ANY WARRANTY; without even the implied
	* warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
	* PURPOSE. See the GNU General Public License for more
	* details.
	*
	* You should have received a copy of the GNU General Public
	* License along with this program; if not, write to the
	* Free Software Foundation, Inc., 59 Temple Place,
	* Suite 330, Boston, MA 02111-1307 USA
	*
	*/

	#include <linux/kernel.h>
	#include <linux/gfp.h>
	#include <linux/module.h>
	#include <linux/init.h>
	#include <linux/proc_fs.h>
	#include <linux/seq_file.h>
	#include <asm/console.h>
	#include <asm/uaccess.h>
	#include <asm/machvec.h>

	#define BASE_DIR "srm_environment" /* Subdir in /proc/ */
	#define NAMED_DIR "named_variables" /* Subdir for known variables */
	#define NUMBERED_DIR "numbered_variables" /* Subdir for all variables */
	#define VERSION "0.0.6" /* Module version */
	#define NAME "srm_env" /* Module name */

	MODULE_AUTHOR("Jan-Benedict Glaw <jbglaw@lug-owl.de>");
	MODULE_DESCRIPTION("Accessing Alpha SRM environment through procfs interface");
	MODULE_LICENSE("GPL");

	typedef struct _srm_env {
	char *name;
	unsigned long id;
	struct proc_dir_entry *proc_entry;
	} srm_env_t;

	static struct proc_dir_entry *base_dir;
	static struct proc_dir_entry *named_dir;
	static struct proc_dir_entry *numbered_dir;
	static char number[256][4];

	static srm_env_t srm_named_entries[] = {
	{ "auto_action", ENV_AUTO_ACTION },
	{ "boot_dev", ENV_BOOT_DEV },
	{ "bootdef_dev", ENV_BOOTDEF_DEV },
	{ "booted_dev", ENV_BOOTED_DEV },
	{ "boot_file", ENV_BOOT_FILE },
	{ "booted_file", ENV_BOOTED_FILE },
	{ "boot_osflags", ENV_BOOT_OSFLAGS },
	{ "booted_osflags", ENV_BOOTED_OSFLAGS },
	{ "boot_reset", ENV_BOOT_RESET },
	{ "dump_dev", ENV_DUMP_DEV },
	{ "enable_audit", ENV_ENABLE_AUDIT },
	{ "license", ENV_LICENSE },
	{ "char_set", ENV_CHAR_SET },
	{ "language", ENV_LANGUAGE },
	{ "tty_dev", ENV_TTY_DEV },
	{ NULL, 0 },
	};
	static srm_env_t srm_numbered_entries[256];


	static int srm_env_proc_show(struct seq_file m, void v)
	{
	unsigned long ret;
	srm_env_t *entry;
	char *page;

	entry = m->private;
	page = (char *)__get_free_page(GFP_USER);
	if (!page)
	return -ENOMEM;

	ret = callback_getenv(entry->id, page, PAGE_SIZE);

	if ((ret >> 61) == 0) {
	seq_write(m, page, ret);
	ret = 0;
	} else
	ret = -EFAULT;
	free_page((unsigned long)page);
	return ret;
	}

	static int srm_env_proc_open(struct inode inode, struct file file)
	{
	return single_open(file, srm_env_proc_show, PDE(inode)->data);
	}

	static ssize_t srm_env_proc_write(struct file file, const char __user buffer,
	size_t count, loff_t *pos)
	{
	int res;
	srm_env_t *entry = PDE(file->f_path.dentry->d_inode)->data;
	char buf = (char ) __get_free_page(GFP_USER);
	unsigned long ret1, ret2;

	if (!buf)
	return -ENOMEM;

	res = -EINVAL;
	if (count >= PAGE_SIZE)
	goto out;

	res = -EFAULT;
	if (copy_from_user(buf, buffer, count))
	goto out;
	buf[count] = '\0';

	ret1 = callback_setenv(entry->id, buf, count);
	if ((ret1 >> 61) == 0) {
	do
	ret2 = callback_save_env();
	while((ret2 >> 61) == 1);
	res = (int) ret1;
	}

	out:
	free_page((unsigned long)buf);
	return res;
	}

	static const struct file_operations srm_env_proc_fops = {
	.owner = THIS_MODULE,
	.open = srm_env_proc_open,
	.read = seq_read,
	.llseek = seq_lseek,
	.release = single_release,
	.write = srm_env_proc_write,
	};

	static void
	srm_env_cleanup(void)
	{
	srm_env_t *entry;
	unsigned long var_num;

	if (base_dir) {
	/*
	* Remove named entries
	*/
	if (named_dir) {
	entry = srm_named_entries;
	while (entry->name != NULL && entry->id != 0) {
	if (entry->proc_entry) {
	remove_proc_entry(entry->name,
	named_dir);
	entry->proc_entry = NULL;
	}
	entry++;
	}
	remove_proc_entry(NAMED_DIR, base_dir);
	}

	/*
	* Remove numbered entries
	*/
	if (numbered_dir) {
	for (var_num = 0; var_num <= 255; var_num++) {
	entry = &srm_numbered_entries[var_num];

	if (entry->proc_entry) {
	remove_proc_entry(entry->name,
	numbered_dir);
	entry->proc_entry = NULL;
	entry->name = NULL;
	}
	}
	remove_proc_entry(NUMBERED_DIR, base_dir);
	}

	remove_proc_entry(BASE_DIR, NULL);
	}

	return;
	}

	static int __init
	srm_env_init(void)
	{
	srm_env_t *entry;
	unsigned long var_num;

	/*
	* Check system
	*/
	if (!alpha_using_srm) {
	printk(KERN_INFO "%s: This Alpha system doesn't "
	"know about SRM (or you've booted "
	"SRM->MILO->Linux, which gets "
	"misdetected)...\n", __func__);
	return -ENODEV;
	}

	/*
	* Init numbers
	*/
	for (var_num = 0; var_num <= 255; var_num++)
	sprintf(number[var_num], "%ld", var_num);

	/*
	* Create base directory
	*/
	base_dir = proc_mkdir(BASE_DIR, NULL);
	if (!base_dir) {
	printk(KERN_ERR "Couldn't create base dir /proc/%s\n",
	BASE_DIR);
	goto cleanup;
	}

	/*
	* Create per-name subdirectory
	*/
	named_dir = proc_mkdir(NAMED_DIR, base_dir);
	if (!named_dir) {
	printk(KERN_ERR "Couldn't create dir /proc/%s/%s\n",
	BASE_DIR, NAMED_DIR);
	goto cleanup;
	}

	/*
	* Create per-number subdirectory
	*/
	numbered_dir = proc_mkdir(NUMBERED_DIR, base_dir);
	if (!numbered_dir) {
	printk(KERN_ERR "Couldn't create dir /proc/%s/%s\n",
	BASE_DIR, NUMBERED_DIR);
	goto cleanup;

	}

	/*
	* Create all named nodes
	*/
	entry = srm_named_entries;
	while (entry->name && entry->id) {
	entry->proc_entry = proc_create_data(entry->name, 0644, named_dir,
	&srm_env_proc_fops, entry);
	if (!entry->proc_entry)
	goto cleanup;
	entry++;
	}

	/*
	* Create all numbered nodes
	*/
	for (var_num = 0; var_num <= 255; var_num++) {
	entry = &srm_numbered_entries[var_num];
	entry->name = number[var_num];

	entry->proc_entry = proc_create_data(entry->name, 0644, numbered_dir,
	&srm_env_proc_fops, entry);
	if (!entry->proc_entry)
	goto cleanup;

	entry->id = var_num;
	}

	printk(KERN_INFO "%s: version %s loaded successfully\n", NAME,
	VERSION);

	return 0;

	cleanup:
	srm_env_cleanup();

	return -ENOMEM;
	}

	static void __exit
	srm_env_exit(void)
	{
	srm_env_cleanup();
	printk(KERN_INFO "%s: unloaded successfully\n", NAME);

	return;
	}

	module_init(srm_env_init);
	module_exit(srm_env_exit);