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b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
d475f942 MH |
2 | /* |
3 | * IOCTL interface for SCLP | |
4 | * | |
5 | * Copyright IBM Corp. 2012 | |
6 | * | |
7 | * Author: Michael Holzheu <holzheu@linux.vnet.ibm.com> | |
8 | */ | |
9 | ||
10 | #include <linux/compat.h> | |
11 | #include <linux/uaccess.h> | |
12 | #include <linux/miscdevice.h> | |
13 | #include <linux/gfp.h> | |
c1eac0d0 | 14 | #include <linux/init.h> |
d475f942 MH |
15 | #include <linux/ioctl.h> |
16 | #include <linux/fs.h> | |
d475f942 MH |
17 | #include <asm/sclp_ctl.h> |
18 | #include <asm/sclp.h> | |
19 | ||
20 | #include "sclp.h" | |
21 | ||
22 | /* | |
23 | * Supported command words | |
24 | */ | |
25 | static unsigned int sclp_ctl_sccb_wlist[] = { | |
26 | 0x00400002, | |
27 | 0x00410002, | |
28 | }; | |
29 | ||
30 | /* | |
31 | * Check if command word is supported | |
32 | */ | |
33 | static int sclp_ctl_cmdw_supported(unsigned int cmdw) | |
34 | { | |
35 | int i; | |
36 | ||
37 | for (i = 0; i < ARRAY_SIZE(sclp_ctl_sccb_wlist); i++) { | |
38 | if (cmdw == sclp_ctl_sccb_wlist[i]) | |
39 | return 1; | |
40 | } | |
41 | return 0; | |
42 | } | |
43 | ||
44 | static void __user *u64_to_uptr(u64 value) | |
45 | { | |
46 | if (is_compat_task()) | |
47 | return compat_ptr(value); | |
48 | else | |
49 | return (void __user *)(unsigned long)value; | |
50 | } | |
51 | ||
52 | /* | |
53 | * Start SCLP request | |
54 | */ | |
55 | static int sclp_ctl_ioctl_sccb(void __user *user_area) | |
56 | { | |
57 | struct sclp_ctl_sccb ctl_sccb; | |
58 | struct sccb_header *sccb; | |
532c34b5 | 59 | unsigned long copied; |
d475f942 MH |
60 | int rc; |
61 | ||
62 | if (copy_from_user(&ctl_sccb, user_area, sizeof(ctl_sccb))) | |
63 | return -EFAULT; | |
64 | if (!sclp_ctl_cmdw_supported(ctl_sccb.cmdw)) | |
65 | return -EOPNOTSUPP; | |
66 | sccb = (void *) get_zeroed_page(GFP_KERNEL | GFP_DMA); | |
67 | if (!sccb) | |
68 | return -ENOMEM; | |
532c34b5 MS |
69 | copied = PAGE_SIZE - |
70 | copy_from_user(sccb, u64_to_uptr(ctl_sccb.sccb), PAGE_SIZE); | |
71 | if (offsetof(struct sccb_header, length) + | |
72 | sizeof(sccb->length) > copied || sccb->length > copied) { | |
d475f942 MH |
73 | rc = -EFAULT; |
74 | goto out_free; | |
75 | } | |
532c34b5 MS |
76 | if (sccb->length < 8) { |
77 | rc = -EINVAL; | |
d475f942 MH |
78 | goto out_free; |
79 | } | |
80 | rc = sclp_sync_request(ctl_sccb.cmdw, sccb); | |
81 | if (rc) | |
82 | goto out_free; | |
83 | if (copy_to_user(u64_to_uptr(ctl_sccb.sccb), sccb, sccb->length)) | |
84 | rc = -EFAULT; | |
85 | out_free: | |
86 | free_page((unsigned long) sccb); | |
87 | return rc; | |
88 | } | |
89 | ||
90 | /* | |
91 | * SCLP SCCB ioctl function | |
92 | */ | |
93 | static long sclp_ctl_ioctl(struct file *filp, unsigned int cmd, | |
94 | unsigned long arg) | |
95 | { | |
96 | void __user *argp; | |
97 | ||
98 | if (is_compat_task()) | |
99 | argp = compat_ptr(arg); | |
100 | else | |
101 | argp = (void __user *) arg; | |
102 | switch (cmd) { | |
103 | case SCLP_CTL_SCCB: | |
104 | return sclp_ctl_ioctl_sccb(argp); | |
105 | default: /* unknown ioctl number */ | |
106 | return -ENOTTY; | |
107 | } | |
108 | } | |
109 | ||
110 | /* | |
111 | * File operations | |
112 | */ | |
113 | static const struct file_operations sclp_ctl_fops = { | |
114 | .owner = THIS_MODULE, | |
115 | .open = nonseekable_open, | |
116 | .unlocked_ioctl = sclp_ctl_ioctl, | |
117 | .compat_ioctl = sclp_ctl_ioctl, | |
118 | .llseek = no_llseek, | |
119 | }; | |
120 | ||
121 | /* | |
122 | * Misc device definition | |
123 | */ | |
124 | static struct miscdevice sclp_ctl_device = { | |
125 | .minor = MISC_DYNAMIC_MINOR, | |
126 | .name = "sclp", | |
127 | .fops = &sclp_ctl_fops, | |
128 | }; | |
c1eac0d0 | 129 | builtin_misc_device(sclp_ctl_device); |