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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /fs/debugfs/file.c
downloadlinux-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.gz
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'fs/debugfs/file.c')
-rw-r--r--fs/debugfs/file.c262
1 files changed, 262 insertions, 0 deletions
diff --git a/fs/debugfs/file.c b/fs/debugfs/file.c
new file mode 100644
index 00000000000..548556ff250
--- /dev/null
+++ b/fs/debugfs/file.c
@@ -0,0 +1,262 @@
+/*
+ * 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,
+};
+
+#define simple_type(type, format, temptype, strtolfn) \
+static ssize_t read_file_##type(struct file *file, char __user *user_buf, \
+ size_t count, loff_t *ppos) \
+{ \
+ char buf[32]; \
+ type *val = file->private_data; \
+ \
+ snprintf(buf, sizeof(buf), format "\n", *val); \
+ return simple_read_from_buffer(user_buf, count, ppos, buf, strlen(buf));\
+} \
+static ssize_t write_file_##type(struct file *file, const char __user *user_buf,\
+ size_t count, loff_t *ppos) \
+{ \
+ char *endp; \
+ char buf[32]; \
+ int buf_size; \
+ type *val = file->private_data; \
+ temptype tmp; \
+ \
+ memset(buf, 0x00, sizeof(buf)); \
+ buf_size = min(count, (sizeof(buf)-1)); \
+ if (copy_from_user(buf, user_buf, buf_size)) \
+ return -EFAULT; \
+ \
+ tmp = strtolfn(buf, &endp, 0); \
+ if ((endp == buf) || ((type)tmp != tmp)) \
+ return -EINVAL; \
+ *val = tmp; \
+ return count; \
+} \
+static struct file_operations fops_##type = { \
+ .read = read_file_##type, \
+ .write = write_file_##type, \
+ .open = default_open, \
+};
+simple_type(u8, "%c", unsigned long, simple_strtoul);
+simple_type(u16, "%hi", unsigned long, simple_strtoul);
+simple_type(u32, "%i", unsigned long, simple_strtoul);
+
+/**
+ * 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);
+
+/**
+ * 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);
+
+/**
+ * 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);
+