1 // SPDX-License-Identifier: GPL-2.0
3 * IOCTL interface for SCLP
5 * Copyright IBM Corp. 2012
7 * Author: Michael Holzheu <holzheu@linux.vnet.ibm.com>
10 #include <linux/compat.h>
11 #include <linux/uaccess.h>
12 #include <linux/miscdevice.h>
13 #include <linux/gfp.h>
14 #include <linux/init.h>
15 #include <linux/ioctl.h>
17 #include <asm/compat.h>
18 #include <asm/sclp_ctl.h>
24 * Supported command words
26 static unsigned int sclp_ctl_sccb_wlist[] = {
32 * Check if command word is supported
34 static int sclp_ctl_cmdw_supported(unsigned int cmdw)
38 for (i = 0; i < ARRAY_SIZE(sclp_ctl_sccb_wlist); i++) {
39 if (cmdw == sclp_ctl_sccb_wlist[i])
45 static void __user *u64_to_uptr(u64 value)
48 return compat_ptr(value);
50 return (void __user *)(unsigned long)value;
56 static int sclp_ctl_ioctl_sccb(void __user *user_area)
58 struct sclp_ctl_sccb ctl_sccb;
59 struct sccb_header *sccb;
63 if (copy_from_user(&ctl_sccb, user_area, sizeof(ctl_sccb)))
65 if (!sclp_ctl_cmdw_supported(ctl_sccb.cmdw))
67 sccb = (void *) get_zeroed_page(GFP_KERNEL | GFP_DMA);
71 copy_from_user(sccb, u64_to_uptr(ctl_sccb.sccb), PAGE_SIZE);
72 if (offsetof(struct sccb_header, length) +
73 sizeof(sccb->length) > copied || sccb->length > copied) {
77 if (sccb->length < 8) {
81 rc = sclp_sync_request(ctl_sccb.cmdw, sccb);
84 if (copy_to_user(u64_to_uptr(ctl_sccb.sccb), sccb, sccb->length))
87 free_page((unsigned long) sccb);
92 * SCLP SCCB ioctl function
94 static long sclp_ctl_ioctl(struct file *filp, unsigned int cmd,
100 argp = compat_ptr(arg);
102 argp = (void __user *) arg;
105 return sclp_ctl_ioctl_sccb(argp);
106 default: /* unknown ioctl number */
114 static const struct file_operations sclp_ctl_fops = {
115 .owner = THIS_MODULE,
116 .open = nonseekable_open,
117 .unlocked_ioctl = sclp_ctl_ioctl,
118 .compat_ioctl = sclp_ctl_ioctl,
123 * Misc device definition
125 static struct miscdevice sclp_ctl_device = {
126 .minor = MISC_DYNAMIC_MINOR,
128 .fops = &sclp_ctl_fops,
130 builtin_misc_device(sclp_ctl_device);