diag_misc.c

 1// SPDX-License-Identifier: GPL-2.0
 2/*
 3 * Provide diagnose information via misc device /dev/diag.
 4 *
 5 * Copyright IBM Corp. 2024
 6 */
 7
 8#include <linux/fs.h>
 9#include <linux/init.h>
10#include <linux/ioctl.h>
11#include <linux/kernel.h>
12#include <linux/miscdevice.h>
13#include <linux/types.h>
14
15#include <uapi/asm/diag.h>
16#include "diag_ioctl.h"
17
18static long diag_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
19{
20	long rc;
21
22	switch (cmd) {
23	case DIAG324_GET_PIBLEN:
24		rc = diag324_piblen(arg);
25		break;
26	case DIAG324_GET_PIBBUF:
27		rc = diag324_pibbuf(arg);
28		break;
29	case DIAG310_GET_STRIDE:
30		rc = diag310_memtop_stride(arg);
31		break;
32	case DIAG310_GET_MEMTOPLEN:
33		rc = diag310_memtop_len(arg);
34		break;
35	case DIAG310_GET_MEMTOPBUF:
36		rc = diag310_memtop_buf(arg);
37		break;
38	default:
39		rc = -ENOIOCTLCMD;
40		break;
41	}
42	return rc;
43}
44
45static const struct file_operations fops = {
46	.owner		= THIS_MODULE,
47	.open		= nonseekable_open,
48	.unlocked_ioctl	= diag_ioctl,
49};
50
51static struct miscdevice diagdev = {
52	.name	= "diag",
53	.minor	= MISC_DYNAMIC_MINOR,
54	.fops	= &fops,
55	.mode	= 0444,
56};
57
58static int diag_init(void)
59{
60	return misc_register(&diagdev);
61}
62
63device_initcall(diag_init);