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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * For architectures where we want to allow direct access to the PCI config
4 * stuff - it would probably be preferable on PCs too, but there people
5 * just do it by hand with the magic northbridge registers.
6 */
7
8#include <linux/errno.h>
9#include <linux/pci.h>
10#include <linux/security.h>
11#include <linux/syscalls.h>
12#include <linux/uaccess.h>
13#include "pci.h"
14
15SYSCALL_DEFINE5(pciconfig_read, unsigned long, bus, unsigned long, dfn,
16 unsigned long, off, unsigned long, len, void __user *, buf)
17{
18 struct pci_dev *dev;
19 u8 byte;
20 u16 word;
21 u32 dword;
22 long err;
23 long cfg_ret;
24
25 if (!capable(CAP_SYS_ADMIN))
26 return -EPERM;
27
28 err = -ENODEV;
29 dev = pci_get_domain_bus_and_slot(0, bus, dfn);
30 if (!dev)
31 goto error;
32
33 switch (len) {
34 case 1:
35 cfg_ret = pci_user_read_config_byte(dev, off, &byte);
36 break;
37 case 2:
38 cfg_ret = pci_user_read_config_word(dev, off, &word);
39 break;
40 case 4:
41 cfg_ret = pci_user_read_config_dword(dev, off, &dword);
42 break;
43 default:
44 err = -EINVAL;
45 goto error;
46 }
47
48 err = -EIO;
49 if (cfg_ret != PCIBIOS_SUCCESSFUL)
50 goto error;
51
52 switch (len) {
53 case 1:
54 err = put_user(byte, (unsigned char __user *)buf);
55 break;
56 case 2:
57 err = put_user(word, (unsigned short __user *)buf);
58 break;
59 case 4:
60 err = put_user(dword, (unsigned int __user *)buf);
61 break;
62 }
63 pci_dev_put(dev);
64 return err;
65
66error:
67 /* ??? XFree86 doesn't even check the return value. They
68 just look for 0xffffffff in the output, since that's what
69 they get instead of a machine check on x86. */
70 switch (len) {
71 case 1:
72 put_user(-1, (unsigned char __user *)buf);
73 break;
74 case 2:
75 put_user(-1, (unsigned short __user *)buf);
76 break;
77 case 4:
78 put_user(-1, (unsigned int __user *)buf);
79 break;
80 }
81 pci_dev_put(dev);
82 return err;
83}
84
85SYSCALL_DEFINE5(pciconfig_write, unsigned long, bus, unsigned long, dfn,
86 unsigned long, off, unsigned long, len, void __user *, buf)
87{
88 struct pci_dev *dev;
89 u8 byte;
90 u16 word;
91 u32 dword;
92 int err = 0;
93
94 if (!capable(CAP_SYS_ADMIN) ||
95 security_locked_down(LOCKDOWN_PCI_ACCESS))
96 return -EPERM;
97
98 dev = pci_get_domain_bus_and_slot(0, bus, dfn);
99 if (!dev)
100 return -ENODEV;
101
102 switch (len) {
103 case 1:
104 err = get_user(byte, (u8 __user *)buf);
105 if (err)
106 break;
107 err = pci_user_write_config_byte(dev, off, byte);
108 if (err != PCIBIOS_SUCCESSFUL)
109 err = -EIO;
110 break;
111
112 case 2:
113 err = get_user(word, (u16 __user *)buf);
114 if (err)
115 break;
116 err = pci_user_write_config_word(dev, off, word);
117 if (err != PCIBIOS_SUCCESSFUL)
118 err = -EIO;
119 break;
120
121 case 4:
122 err = get_user(dword, (u32 __user *)buf);
123 if (err)
124 break;
125 err = pci_user_write_config_dword(dev, off, dword);
126 if (err != PCIBIOS_SUCCESSFUL)
127 err = -EIO;
128 break;
129
130 default:
131 err = -EINVAL;
132 break;
133 }
134 pci_dev_put(dev);
135 return err;
136}
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * For architectures where we want to allow direct access to the PCI config
4 * stuff - it would probably be preferable on PCs too, but there people
5 * just do it by hand with the magic northbridge registers.
6 */
7
8#include <linux/errno.h>
9#include <linux/pci.h>
10#include <linux/security.h>
11#include <linux/syscalls.h>
12#include <linux/uaccess.h>
13#include "pci.h"
14
15SYSCALL_DEFINE5(pciconfig_read, unsigned long, bus, unsigned long, dfn,
16 unsigned long, off, unsigned long, len, void __user *, buf)
17{
18 struct pci_dev *dev;
19 u8 byte;
20 u16 word;
21 u32 dword;
22 int err, cfg_ret;
23
24 err = -EPERM;
25 dev = NULL;
26 if (!capable(CAP_SYS_ADMIN))
27 goto error;
28
29 err = -ENODEV;
30 dev = pci_get_domain_bus_and_slot(0, bus, dfn);
31 if (!dev)
32 goto error;
33
34 switch (len) {
35 case 1:
36 cfg_ret = pci_user_read_config_byte(dev, off, &byte);
37 break;
38 case 2:
39 cfg_ret = pci_user_read_config_word(dev, off, &word);
40 break;
41 case 4:
42 cfg_ret = pci_user_read_config_dword(dev, off, &dword);
43 break;
44 default:
45 err = -EINVAL;
46 goto error;
47 }
48
49 err = -EIO;
50 if (cfg_ret)
51 goto error;
52
53 switch (len) {
54 case 1:
55 err = put_user(byte, (u8 __user *)buf);
56 break;
57 case 2:
58 err = put_user(word, (u16 __user *)buf);
59 break;
60 case 4:
61 err = put_user(dword, (u32 __user *)buf);
62 break;
63 }
64 pci_dev_put(dev);
65 return err;
66
67error:
68 /* ??? XFree86 doesn't even check the return value. They
69 just look for 0xffffffff in the output, since that's what
70 they get instead of a machine check on x86. */
71 switch (len) {
72 case 1:
73 put_user(-1, (u8 __user *)buf);
74 break;
75 case 2:
76 put_user(-1, (u16 __user *)buf);
77 break;
78 case 4:
79 put_user(-1, (u32 __user *)buf);
80 break;
81 }
82 pci_dev_put(dev);
83 return err;
84}
85
86SYSCALL_DEFINE5(pciconfig_write, unsigned long, bus, unsigned long, dfn,
87 unsigned long, off, unsigned long, len, void __user *, buf)
88{
89 struct pci_dev *dev;
90 u8 byte;
91 u16 word;
92 u32 dword;
93 int err = 0;
94
95 if (!capable(CAP_SYS_ADMIN) ||
96 security_locked_down(LOCKDOWN_PCI_ACCESS))
97 return -EPERM;
98
99 dev = pci_get_domain_bus_and_slot(0, bus, dfn);
100 if (!dev)
101 return -ENODEV;
102
103 switch (len) {
104 case 1:
105 err = get_user(byte, (u8 __user *)buf);
106 if (err)
107 break;
108 err = pci_user_write_config_byte(dev, off, byte);
109 if (err)
110 err = -EIO;
111 break;
112
113 case 2:
114 err = get_user(word, (u16 __user *)buf);
115 if (err)
116 break;
117 err = pci_user_write_config_word(dev, off, word);
118 if (err)
119 err = -EIO;
120 break;
121
122 case 4:
123 err = get_user(dword, (u32 __user *)buf);
124 if (err)
125 break;
126 err = pci_user_write_config_dword(dev, off, dword);
127 if (err)
128 err = -EIO;
129 break;
130
131 default:
132 err = -EINVAL;
133 break;
134 }
135 pci_dev_put(dev);
136 return err;
137}