1 files changed, 299 insertions, 0 deletions
diff --git a/drivers/oprofile/oprofilefs.c b/drivers/oprofile/oprofilefs.c
new file mode 100644
index 000000000000..d6bae699749a
--- /dev/null
+++ b/drivers/oprofile/oprofilefs.c
@@ -0,0 +1,299 @@
+/**
+ * @file oprofilefs.c
+ *
+ * @remark Copyright 2002 OProfile authors
+ * @remark Read the file COPYING
+ *
+ * @author John Levon
+ *
+ * A simple filesystem for configuration and
+ * access of oprofile.
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/oprofile.h>
+#include <linux/fs.h>
+#include <linux/pagemap.h>
+#include <asm/uaccess.h>
+
+#include "oprof.h"
+
+#define OPROFILEFS_MAGIC 0x6f70726f
+
+DEFINE_SPINLOCK(oprofilefs_lock);
+
+static struct inode * oprofilefs_get_inode(struct super_block * sb, int mode)
+{
+	struct inode * inode = new_inode(sb);
+
+	if (inode) {
+		inode->i_mode = mode;
+		inode->i_uid = 0;
+		inode->i_gid = 0;
+		inode->i_blksize = PAGE_CACHE_SIZE;
+		inode->i_blocks = 0;
+		inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
+	}
+	return inode;
+}
+
+
+static struct super_operations s_ops = {
+	.statfs		= simple_statfs,
+	.drop_inode 	= generic_delete_inode,
+};
+
+
+ssize_t oprofilefs_str_to_user(char const * str, char __user * buf, size_t count, loff_t * offset)
+{
+	return simple_read_from_buffer(buf, count, offset, str, strlen(str));
+}
+
+
+#define TMPBUFSIZE 50
+
+ssize_t oprofilefs_ulong_to_user(unsigned long val, char __user * buf, size_t count, loff_t * offset)
+{
+	char tmpbuf[TMPBUFSIZE];
+	size_t maxlen = snprintf(tmpbuf, TMPBUFSIZE, "%lu\n", val);
+	if (maxlen > TMPBUFSIZE)
+		maxlen = TMPBUFSIZE;
+	return simple_read_from_buffer(buf, count, offset, tmpbuf, maxlen);
+}
+
+
+int oprofilefs_ulong_from_user(unsigned long * val, char const __user * buf, size_t count)
+{
+	char tmpbuf[TMPBUFSIZE];
+
+	if (!count)
+		return 0;
+
+	if (count > TMPBUFSIZE - 1)
+		return -EINVAL;
+
+	memset(tmpbuf, 0x0, TMPBUFSIZE);
+
+	if (copy_from_user(tmpbuf, buf, count))
+		return -EFAULT;
+
+	spin_lock(&oprofilefs_lock);
+	*val = simple_strtoul(tmpbuf, NULL, 0);
+	spin_unlock(&oprofilefs_lock);
+	return 0;
+}
+
+
+static ssize_t ulong_read_file(struct file * file, char __user * buf, size_t count, loff_t * offset)
+{
+	unsigned long * val = file->private_data;
+	return oprofilefs_ulong_to_user(*val, buf, count, offset);
+}
+
+
+static ssize_t ulong_write_file(struct file * file, char const __user * buf, size_t count, loff_t * offset)
+{
+	unsigned long * value = file->private_data;
+	int retval;
+
+	if (*offset)
+		return -EINVAL;
+
+	retval = oprofilefs_ulong_from_user(value, buf, count);
+
+	if (retval)
+		return retval;
+	return count;
+}
+
+
+static int default_open(struct inode * inode, struct file * filp)
+{
+	if (inode->u.generic_ip)
+		filp->private_data = inode->u.generic_ip;
+	return 0;
+}
+
+
+static struct file_operations ulong_fops = {
+	.read		= ulong_read_file,
+	.write		= ulong_write_file,
+	.open		= default_open,
+};
+
+
+static struct file_operations ulong_ro_fops = {
+	.read		= ulong_read_file,
+	.open		= default_open,
+};
+
+
+static struct dentry * __oprofilefs_create_file(struct super_block * sb,
+	struct dentry * root, char const * name, struct file_operations * fops,
+	int perm)
+{
+	struct dentry * dentry;
+	struct inode * inode;
+
+	dentry = d_alloc_name(root, name);
+	if (!dentry)
+		return NULL;
+	inode = oprofilefs_get_inode(sb, S_IFREG | perm);
+	if (!inode) {
+		dput(dentry);
+		return NULL;
+	}
+	inode->i_fop = fops;
+	d_add(dentry, inode);
+	return dentry;
+}
+
+
+int oprofilefs_create_ulong(struct super_block * sb, struct dentry * root,
+	char const * name, unsigned long * val)
+{
+	struct dentry * d = __oprofilefs_create_file(sb, root, name,
+						     &ulong_fops, 0644);
+	if (!d)
+		return -EFAULT;
+
+	d->d_inode->u.generic_ip = val;
+	return 0;
+}
+
+
+int oprofilefs_create_ro_ulong(struct super_block * sb, struct dentry * root,
+	char const * name, unsigned long * val)
+{
+	struct dentry * d = __oprofilefs_create_file(sb, root, name,
+						     &ulong_ro_fops, 0444);
+	if (!d)
+		return -EFAULT;
+
+	d->d_inode->u.generic_ip = val;
+	return 0;
+}
+
+
+static ssize_t atomic_read_file(struct file * file, char __user * buf, size_t count, loff_t * offset)
+{
+	atomic_t * val = file->private_data;
+	return oprofilefs_ulong_to_user(atomic_read(val), buf, count, offset);
+}
+ 
+
+static struct file_operations atomic_ro_fops = {
+	.read		= atomic_read_file,
+	.open		= default_open,
+};
+ 
+
+int oprofilefs_create_ro_atomic(struct super_block * sb, struct dentry * root,
+	char const * name, atomic_t * val)
+{
+	struct dentry * d = __oprofilefs_create_file(sb, root, name,
+						     &atomic_ro_fops, 0444);
+	if (!d)
+		return -EFAULT;
+
+	d->d_inode->u.generic_ip = val;
+	return 0;
+}
+
+ 
+int oprofilefs_create_file(struct super_block * sb, struct dentry * root,
+	char const * name, struct file_operations * fops)
+{
+	if (!__oprofilefs_create_file(sb, root, name, fops, 0644))
+		return -EFAULT;
+	return 0;
+}
+
+
+int oprofilefs_create_file_perm(struct super_block * sb, struct dentry * root,
+	char const * name, struct file_operations * fops, int perm)
+{
+	if (!__oprofilefs_create_file(sb, root, name, fops, perm))
+		return -EFAULT;
+	return 0;
+}
+
+
+struct dentry * oprofilefs_mkdir(struct super_block * sb,
+	struct dentry * root, char const * name)
+{
+	struct dentry * dentry;
+	struct inode * inode;
+
+	dentry = d_alloc_name(root, name);
+	if (!dentry)
+		return NULL;
+	inode = oprofilefs_get_inode(sb, S_IFDIR | 0755);
+	if (!inode) {
+		dput(dentry);
+		return NULL;
+	}
+	inode->i_op = &simple_dir_inode_operations;
+	inode->i_fop = &simple_dir_operations;
+	d_add(dentry, inode);
+	return dentry;
+}
+
+
+static int oprofilefs_fill_super(struct super_block * sb, void * data, int silent)
+{
+	struct inode * root_inode;
+	struct dentry * root_dentry;
+
+	sb->s_blocksize = PAGE_CACHE_SIZE;
+	sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
+	sb->s_magic = OPROFILEFS_MAGIC;
+	sb->s_op = &s_ops;
+	sb->s_time_gran = 1;
+
+	root_inode = oprofilefs_get_inode(sb, S_IFDIR | 0755);
+	if (!root_inode)
+		return -ENOMEM;
+	root_inode->i_op = &simple_dir_inode_operations;
+	root_inode->i_fop = &simple_dir_operations;
+	root_dentry = d_alloc_root(root_inode);
+	if (!root_dentry) {
+		iput(root_inode);
+		return -ENOMEM;
+	}
+
+	sb->s_root = root_dentry;
+
+	oprofile_create_files(sb, root_dentry);
+
+	// FIXME: verify kill_litter_super removes our dentries
+	return 0;
+}
+
+
+static struct super_block *oprofilefs_get_sb(struct file_system_type *fs_type,
+	int flags, const char *dev_name, void *data)
+{
+	return get_sb_single(fs_type, flags, data, oprofilefs_fill_super);
+}
+
+
+static struct file_system_type oprofilefs_type = {
+	.owner		= THIS_MODULE,
+	.name		= "oprofilefs",
+	.get_sb		= oprofilefs_get_sb,
+	.kill_sb	= kill_litter_super,
+};
+
+
+int __init oprofilefs_register(void)
+{
+	return register_filesystem(&oprofilefs_type);
+}
+
+
+void __exit oprofilefs_unregister(void)
+{
+	unregister_filesystem(&oprofilefs_type);
+}