From 76cb841cb886eef6b3bee341a2266c76578724ad Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Mon, 6 May 2024 03:02:30 +0200 Subject: Adding upstream version 4.19.249. Signed-off-by: Daniel Baumann --- arch/s390/hypfs/hypfs_dbfs.c | 105 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 105 insertions(+) create mode 100644 arch/s390/hypfs/hypfs_dbfs.c (limited to 'arch/s390/hypfs/hypfs_dbfs.c') diff --git a/arch/s390/hypfs/hypfs_dbfs.c b/arch/s390/hypfs/hypfs_dbfs.c new file mode 100644 index 000000000..b9bdf5c19 --- /dev/null +++ b/arch/s390/hypfs/hypfs_dbfs.c @@ -0,0 +1,105 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Hypervisor filesystem for Linux on s390 - debugfs interface + * + * Copyright IBM Corp. 2010 + * Author(s): Michael Holzheu + */ + +#include +#include "hypfs.h" + +static struct dentry *dbfs_dir; + +static struct hypfs_dbfs_data *hypfs_dbfs_data_alloc(struct hypfs_dbfs_file *f) +{ + struct hypfs_dbfs_data *data; + + data = kmalloc(sizeof(*data), GFP_KERNEL); + if (!data) + return NULL; + data->dbfs_file = f; + return data; +} + +static void hypfs_dbfs_data_free(struct hypfs_dbfs_data *data) +{ + data->dbfs_file->data_free(data->buf_free_ptr); + kfree(data); +} + +static ssize_t dbfs_read(struct file *file, char __user *buf, + size_t size, loff_t *ppos) +{ + struct hypfs_dbfs_data *data; + struct hypfs_dbfs_file *df; + ssize_t rc; + + if (*ppos != 0) + return 0; + + df = file_inode(file)->i_private; + mutex_lock(&df->lock); + data = hypfs_dbfs_data_alloc(df); + if (!data) { + mutex_unlock(&df->lock); + return -ENOMEM; + } + rc = df->data_create(&data->buf, &data->buf_free_ptr, &data->size); + if (rc) { + mutex_unlock(&df->lock); + kfree(data); + return rc; + } + mutex_unlock(&df->lock); + + rc = simple_read_from_buffer(buf, size, ppos, data->buf, data->size); + hypfs_dbfs_data_free(data); + return rc; +} + +static long dbfs_ioctl(struct file *file, unsigned int cmd, unsigned long arg) +{ + struct hypfs_dbfs_file *df = file_inode(file)->i_private; + long rc; + + mutex_lock(&df->lock); + if (df->unlocked_ioctl) + rc = df->unlocked_ioctl(file, cmd, arg); + else + rc = -ENOTTY; + mutex_unlock(&df->lock); + return rc; +} + +static const struct file_operations dbfs_ops = { + .read = dbfs_read, + .llseek = no_llseek, + .unlocked_ioctl = dbfs_ioctl, +}; + +int hypfs_dbfs_create_file(struct hypfs_dbfs_file *df) +{ + df->dentry = debugfs_create_file(df->name, 0400, dbfs_dir, df, + &dbfs_ops); + if (IS_ERR(df->dentry)) + return PTR_ERR(df->dentry); + mutex_init(&df->lock); + return 0; +} + +void hypfs_dbfs_remove_file(struct hypfs_dbfs_file *df) +{ + debugfs_remove(df->dentry); +} + +int hypfs_dbfs_init(void) +{ + dbfs_dir = debugfs_create_dir("s390_hypfs", NULL); + return PTR_ERR_OR_ZERO(dbfs_dir); +} + +void hypfs_dbfs_exit(void) +{ + debugfs_remove(dbfs_dir); +} -- cgit v1.2.3