cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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uvc_debugfs.c (2520B)

      1// SPDX-License-Identifier: GPL-2.0-or-later
      2/*
      3 *      uvc_debugfs.c --  USB Video Class driver - Debugging support
      4 *
      5 *      Copyright (C) 2011
      6 *          Laurent Pinchart (laurent.pinchart@ideasonboard.com)
      7 */
      8
      9#include <linux/module.h>
     10#include <linux/debugfs.h>
     11#include <linux/slab.h>
     12#include <linux/usb.h>
     13
     14#include "uvcvideo.h"
     15
     16/* -----------------------------------------------------------------------------
     17 * Statistics
     18 */
     19
     20#define UVC_DEBUGFS_BUF_SIZE	1024
     21
     22struct uvc_debugfs_buffer {
     23	size_t count;
     24	char data[UVC_DEBUGFS_BUF_SIZE];
     25};
     26
     27static int uvc_debugfs_stats_open(struct inode *inode, struct file *file)
     28{
     29	struct uvc_streaming *stream = inode->i_private;
     30	struct uvc_debugfs_buffer *buf;
     31
     32	buf = kmalloc(sizeof(*buf), GFP_KERNEL);
     33	if (buf == NULL)
     34		return -ENOMEM;
     35
     36	buf->count = uvc_video_stats_dump(stream, buf->data, sizeof(buf->data));
     37
     38	file->private_data = buf;
     39	return 0;
     40}
     41
     42static ssize_t uvc_debugfs_stats_read(struct file *file, char __user *user_buf,
     43				      size_t nbytes, loff_t *ppos)
     44{
     45	struct uvc_debugfs_buffer *buf = file->private_data;
     46
     47	return simple_read_from_buffer(user_buf, nbytes, ppos, buf->data,
     48				       buf->count);
     49}
     50
     51static int uvc_debugfs_stats_release(struct inode *inode, struct file *file)
     52{
     53	kfree(file->private_data);
     54	file->private_data = NULL;
     55
     56	return 0;
     57}
     58
     59static const struct file_operations uvc_debugfs_stats_fops = {
     60	.owner = THIS_MODULE,
     61	.open = uvc_debugfs_stats_open,
     62	.llseek = no_llseek,
     63	.read = uvc_debugfs_stats_read,
     64	.release = uvc_debugfs_stats_release,
     65};
     66
     67/* -----------------------------------------------------------------------------
     68 * Global and stream initialization/cleanup
     69 */
     70
     71static struct dentry *uvc_debugfs_root_dir;
     72
     73void uvc_debugfs_init_stream(struct uvc_streaming *stream)
     74{
     75	struct usb_device *udev = stream->dev->udev;
     76	char dir_name[33];
     77
     78	if (uvc_debugfs_root_dir == NULL)
     79		return;
     80
     81	snprintf(dir_name, sizeof(dir_name), "%u-%u-%u", udev->bus->busnum,
     82		 udev->devnum, stream->intfnum);
     83
     84	stream->debugfs_dir = debugfs_create_dir(dir_name,
     85						 uvc_debugfs_root_dir);
     86
     87	debugfs_create_file("stats", 0444, stream->debugfs_dir, stream,
     88			    &uvc_debugfs_stats_fops);
     89}
     90
     91void uvc_debugfs_cleanup_stream(struct uvc_streaming *stream)
     92{
     93	debugfs_remove_recursive(stream->debugfs_dir);
     94	stream->debugfs_dir = NULL;
     95}
     96
     97void uvc_debugfs_init(void)
     98{
     99	uvc_debugfs_root_dir = debugfs_create_dir("uvcvideo", usb_debug_root);
    100}
    101
    102void uvc_debugfs_cleanup(void)
    103{
    104	debugfs_remove_recursive(uvc_debugfs_root_dir);
    105}