/* *  file.c - part of debugfs, a tiny little debug file system * *  Copyright (C) 2004 Greg Kroah-Hartman <greg@kroah.com> *  Copyright (C) 2004 IBM Inc. * *	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. * *  debugfs is for people to use instead of /proc or /sys. *  See Documentation/DocBook/kernel-api for more details. * */ #include <linux/config.h>#include <linux/module.h>#include <linux/fs.h>#include <linux/pagemap.h>#include <linux/debugfs.h> static ssize_t default_read_file(struct file *file, char __user *buf,				 size_t count, loff_t *ppos){	return 0;} static ssize_t default_write_file(struct file *file, const char __user *buf,				   size_t count, loff_t *ppos){	return count;} static int default_open(struct inode *inode, struct file *file){	if (inode->u.generic_ip)		file->private_data = inode->u.generic_ip; 	return 0;} struct file_operations debugfs_file_operations = {	.read =		default_read_file,	.write =	default_write_file,	.open =		default_open,}; static void debugfs_u8_set(void *data, u64 val){	*(u8 *)data = val;}static u64 debugfs_u8_get(void *data){	return *(u8 *)data;}DEFINE_SIMPLE_ATTRIBUTE(fops_u8, debugfs_u8_get, debugfs_u8_set, "%llu\n"); /** * debugfs_create_u8 - create a file in the debugfs filesystem that is used to read and write a unsigned 8 bit value. * * @name: a pointer to a string containing the name of the file to create. * @mode: the permission that the file should have * @parent: a pointer to the parent dentry for this file.  This should be a *          directory dentry if set.  If this paramater is NULL, then the *          file will be created in the root of the debugfs filesystem. * @value: a pointer to the variable that the file should read to and write *         from. * * This function creates a file in debugfs with the given name that * contains the value of the variable @value.  If the @mode variable is so * set, it can be read from, and written to. * * This function will return a pointer to a dentry if it succeeds.  This * pointer must be passed to the debugfs_remove() function when the file is * to be removed (no automatic cleanup happens if your module is unloaded, * you are responsible here.)  If an error occurs, NULL will be returned. * * If debugfs is not enabled in the kernel, the value -ENODEV will be * returned.  It is not wise to check for this value, but rather, check for * NULL or !NULL instead as to eliminate the need for #ifdef in the calling * code. */struct dentry *debugfs_create_u8(const char *name, mode_t mode,				 struct dentry *parent, u8 *value){	return debugfs_create_file(name, mode, parent, value, &fops_u8);}EXPORT_SYMBOL_GPL(debugfs_create_u8); static void debugfs_u16_set(void *data, u64 val){	*(u16 *)data = val;}static u64 debugfs_u16_get(void *data){	return *(u16 *)data;}DEFINE_SIMPLE_ATTRIBUTE(fops_u16, debugfs_u16_get, debugfs_u16_set, "%llu\n"); /** * debugfs_create_u16 - create a file in the debugfs filesystem that is used to read and write a unsigned 8 bit value. * * @name: a pointer to a string containing the name of the file to create. * @mode: the permission that the file should have * @parent: a pointer to the parent dentry for this file.  This should be a *          directory dentry if set.  If this paramater is NULL, then the *          file will be created in the root of the debugfs filesystem. * @value: a pointer to the variable that the file should read to and write *         from. * * This function creates a file in debugfs with the given name that * contains the value of the variable @value.  If the @mode variable is so * set, it can be read from, and written to. * * This function will return a pointer to a dentry if it succeeds.  This * pointer must be passed to the debugfs_remove() function when the file is * to be removed (no automatic cleanup happens if your module is unloaded, * you are responsible here.)  If an error occurs, NULL will be returned. * * If debugfs is not enabled in the kernel, the value -ENODEV will be * returned.  It is not wise to check for this value, but rather, check for * NULL or !NULL instead as to eliminate the need for #ifdef in the calling * code. */struct dentry *debugfs_create_u16(const char *name, mode_t mode,				  struct dentry *parent, u16 *value){	return debugfs_create_file(name, mode, parent, value, &fops_u16);}EXPORT_SYMBOL_GPL(debugfs_create_u16); static void debugfs_u32_set(void *data, u64 val){	*(u32 *)data = val;}static u64 debugfs_u32_get(void *data){	return *(u32 *)data;}DEFINE_SIMPLE_ATTRIBUTE(fops_u32, debugfs_u32_get, debugfs_u32_set, "%llu\n"); /** * debugfs_create_u32 - create a file in the debugfs filesystem that is used to read and write a unsigned 8 bit value. * * @name: a pointer to a string containing the name of the file to create. * @mode: the permission that the file should have * @parent: a pointer to the parent dentry for this file.  This should be a *          directory dentry if set.  If this paramater is NULL, then the *          file will be created in the root of the debugfs filesystem. * @value: a pointer to the variable that the file should read to and write *         from. * * This function creates a file in debugfs with the given name that * contains the value of the variable @value.  If the @mode variable is so * set, it can be read from, and written to. * * This function will return a pointer to a dentry if it succeeds.  This * pointer must be passed to the debugfs_remove() function when the file is * to be removed (no automatic cleanup happens if your module is unloaded, * you are responsible here.)  If an error occurs, NULL will be returned. * * If debugfs is not enabled in the kernel, the value -ENODEV will be * returned.  It is not wise to check for this value, but rather, check for * NULL or !NULL instead as to eliminate the need for #ifdef in the calling * code. */struct dentry *debugfs_create_u32(const char *name, mode_t mode,				 struct dentry *parent, u32 *value){	return debugfs_create_file(name, mode, parent, value, &fops_u32);}EXPORT_SYMBOL_GPL(debugfs_create_u32); static ssize_t read_file_bool(struct file *file, char __user *user_buf,			      size_t count, loff_t *ppos){	char buf[3];	u32 *val = file->private_data;		if (*val)		buf[0] = 'Y';	else		buf[0] = 'N';	buf[1] = '\n';	buf[2] = 0x00;	return simple_read_from_buffer(user_buf, count, ppos, buf, 2);} static ssize_t write_file_bool(struct file *file, const char __user *user_buf,			       size_t count, loff_t *ppos){	char buf[32];	int buf_size;	u32 *val = file->private_data; 	buf_size = min(count, (sizeof(buf)-1));	if (copy_from_user(buf, user_buf, buf_size))		return -EFAULT; 	switch (buf[0]) {	case 'y':	case 'Y':	case '1':		*val = 1;		break;	case 'n':	case 'N':	case '0':		*val = 0;		break;	}		return count;} static struct file_operations fops_bool = {	.read =		read_file_bool,	.write =	write_file_bool,	.open =		default_open,}; /** * debugfs_create_bool - create a file in the debugfs filesystem that is used to read and write a boolean value. * * @name: a pointer to a string containing the name of the file to create. * @mode: the permission that the file should have * @parent: a pointer to the parent dentry for this file.  This should be a *          directory dentry if set.  If this paramater is NULL, then the *          file will be created in the root of the debugfs filesystem. * @value: a pointer to the variable that the file should read to and write *         from. * * This function creates a file in debugfs with the given name that * contains the value of the variable @value.  If the @mode variable is so * set, it can be read from, and written to. * * This function will return a pointer to a dentry if it succeeds.  This * pointer must be passed to the debugfs_remove() function when the file is * to be removed (no automatic cleanup happens if your module is unloaded, * you are responsible here.)  If an error occurs, NULL will be returned. * * If debugfs is not enabled in the kernel, the value -ENODEV will be * returned.  It is not wise to check for this value, but rather, check for * NULL or !NULL instead as to eliminate the need for #ifdef in the calling * code. */struct dentry *debugfs_create_bool(const char *name, mode_t mode,				   struct dentry *parent, u32 *value){	return debugfs_create_file(name, mode, parent, value, &fops_bool);}EXPORT_SYMBOL_GPL(debugfs_create_bool);