cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
Log | Files | Refs | README | LICENSE | sfeed.txt

tape_class.c (2955B)

      1// SPDX-License-Identifier: GPL-2.0
      2/*
      3 * Copyright IBM Corp. 2004
      4 *
      5 * Tape class device support
      6 *
      7 * Author: Stefan Bader <shbader@de.ibm.com>
      8 * Based on simple class device code by Greg K-H
      9 */
     10
     11#define KMSG_COMPONENT "tape"
     12#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
     13
     14#include <linux/slab.h>
     15
     16#include "tape_class.h"
     17
     18MODULE_AUTHOR("Stefan Bader <shbader@de.ibm.com>");
     19MODULE_DESCRIPTION(
     20	"Copyright IBM Corp. 2004   All Rights Reserved.\n"
     21	"tape_class.c"
     22);
     23MODULE_LICENSE("GPL");
     24
     25static struct class *tape_class;
     26
     27/*
     28 * Register a tape device and return a pointer to the cdev structure.
     29 *
     30 * device
     31 *	The pointer to the struct device of the physical (base) device.
     32 * drivername
     33 *	The pointer to the drivers name for it's character devices.
     34 * dev
     35 *	The intended major/minor number. The major number may be 0 to
     36 *	get a dynamic major number.
     37 * fops
     38 *	The pointer to the drivers file operations for the tape device.
     39 * devname
     40 *	The pointer to the name of the character device.
     41 */
     42struct tape_class_device *register_tape_dev(
     43	struct device *		device,
     44	dev_t			dev,
     45	const struct file_operations *fops,
     46	char *			device_name,
     47	char *			mode_name)
     48{
     49	struct tape_class_device *	tcd;
     50	int		rc;
     51	char *		s;
     52
     53	tcd = kzalloc(sizeof(struct tape_class_device), GFP_KERNEL);
     54	if (!tcd)
     55		return ERR_PTR(-ENOMEM);
     56
     57	strlcpy(tcd->device_name, device_name, TAPECLASS_NAME_LEN);
     58	for (s = strchr(tcd->device_name, '/'); s; s = strchr(s, '/'))
     59		*s = '!';
     60	strlcpy(tcd->mode_name, mode_name, TAPECLASS_NAME_LEN);
     61	for (s = strchr(tcd->mode_name, '/'); s; s = strchr(s, '/'))
     62		*s = '!';
     63
     64	tcd->char_device = cdev_alloc();
     65	if (!tcd->char_device) {
     66		rc = -ENOMEM;
     67		goto fail_with_tcd;
     68	}
     69
     70	tcd->char_device->owner = fops->owner;
     71	tcd->char_device->ops   = fops;
     72
     73	rc = cdev_add(tcd->char_device, dev, 1);
     74	if (rc)
     75		goto fail_with_cdev;
     76
     77	tcd->class_device = device_create(tape_class, device,
     78					  tcd->char_device->dev, NULL,
     79					  "%s", tcd->device_name);
     80	rc = PTR_ERR_OR_ZERO(tcd->class_device);
     81	if (rc)
     82		goto fail_with_cdev;
     83	rc = sysfs_create_link(
     84		&device->kobj,
     85		&tcd->class_device->kobj,
     86		tcd->mode_name
     87	);
     88	if (rc)
     89		goto fail_with_class_device;
     90
     91	return tcd;
     92
     93fail_with_class_device:
     94	device_destroy(tape_class, tcd->char_device->dev);
     95
     96fail_with_cdev:
     97	cdev_del(tcd->char_device);
     98
     99fail_with_tcd:
    100	kfree(tcd);
    101
    102	return ERR_PTR(rc);
    103}
    104EXPORT_SYMBOL(register_tape_dev);
    105
    106void unregister_tape_dev(struct device *device, struct tape_class_device *tcd)
    107{
    108	if (tcd != NULL && !IS_ERR(tcd)) {
    109		sysfs_remove_link(&device->kobj, tcd->mode_name);
    110		device_destroy(tape_class, tcd->char_device->dev);
    111		cdev_del(tcd->char_device);
    112		kfree(tcd);
    113	}
    114}
    115EXPORT_SYMBOL(unregister_tape_dev);
    116
    117
    118static int __init tape_init(void)
    119{
    120	tape_class = class_create(THIS_MODULE, "tape390");
    121
    122	return 0;
    123}
    124
    125static void __exit tape_exit(void)
    126{
    127	class_destroy(tape_class);
    128	tape_class = NULL;
    129}
    130
    131postcore_initcall(tape_init);
    132module_exit(tape_exit);