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1/*
2 * pci_syscall.c
3 *
4 * For architectures where we want to allow direct access
5 * to the PCI config stuff - it would probably be preferable
6 * on PCs too, but there people just do it by hand with the
7 * magic northbridge registers..
8 */
9
10#include <linux/errno.h>
11#include <linux/pci.h>
12#include <linux/syscalls.h>
13#include <asm/uaccess.h>
14#include "pci.h"
15
16SYSCALL_DEFINE5(pciconfig_read, unsigned long, bus, unsigned long, dfn,
17 unsigned long, off, unsigned long, len, void __user *, buf)
18{
19 struct pci_dev *dev;
20 u8 byte;
21 u16 word;
22 u32 dword;
23 long err;
24 long cfg_ret;
25
26 if (!capable(CAP_SYS_ADMIN))
27 return -EPERM;
28
29 err = -ENODEV;
30 dev = pci_get_bus_and_slot(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 != PCIBIOS_SUCCESSFUL)
51 goto error;
52
53 switch (len) {
54 case 1:
55 err = put_user(byte, (unsigned char __user *)buf);
56 break;
57 case 2:
58 err = put_user(word, (unsigned short __user *)buf);
59 break;
60 case 4:
61 err = put_user(dword, (unsigned int __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, (unsigned char __user *)buf);
74 break;
75 case 2:
76 put_user(-1, (unsigned short __user *)buf);
77 break;
78 case 4:
79 put_user(-1, (unsigned int __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 return -EPERM;
97
98 dev = pci_get_bus_and_slot(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 long err;
23 int cfg_ret;
24
25 err = -EPERM;
26 dev = NULL;
27 if (!capable(CAP_SYS_ADMIN))
28 goto error;
29
30 err = -ENODEV;
31 dev = pci_get_domain_bus_and_slot(0, bus, dfn);
32 if (!dev)
33 goto error;
34
35 switch (len) {
36 case 1:
37 cfg_ret = pci_user_read_config_byte(dev, off, &byte);
38 break;
39 case 2:
40 cfg_ret = pci_user_read_config_word(dev, off, &word);
41 break;
42 case 4:
43 cfg_ret = pci_user_read_config_dword(dev, off, &dword);
44 break;
45 default:
46 err = -EINVAL;
47 goto error;
48 }
49
50 err = -EIO;
51 if (cfg_ret)
52 goto error;
53
54 switch (len) {
55 case 1:
56 err = put_user(byte, (unsigned char __user *)buf);
57 break;
58 case 2:
59 err = put_user(word, (unsigned short __user *)buf);
60 break;
61 case 4:
62 err = put_user(dword, (unsigned int __user *)buf);
63 break;
64 }
65 pci_dev_put(dev);
66 return err;
67
68error:
69 /* ??? XFree86 doesn't even check the return value. They
70 just look for 0xffffffff in the output, since that's what
71 they get instead of a machine check on x86. */
72 switch (len) {
73 case 1:
74 put_user(-1, (unsigned char __user *)buf);
75 break;
76 case 2:
77 put_user(-1, (unsigned short __user *)buf);
78 break;
79 case 4:
80 put_user(-1, (unsigned int __user *)buf);
81 break;
82 }
83 pci_dev_put(dev);
84 return err;
85}
86
87SYSCALL_DEFINE5(pciconfig_write, unsigned long, bus, unsigned long, dfn,
88 unsigned long, off, unsigned long, len, void __user *, buf)
89{
90 struct pci_dev *dev;
91 u8 byte;
92 u16 word;
93 u32 dword;
94 int err = 0;
95
96 if (!capable(CAP_SYS_ADMIN) ||
97 security_locked_down(LOCKDOWN_PCI_ACCESS))
98 return -EPERM;
99
100 dev = pci_get_domain_bus_and_slot(0, bus, dfn);
101 if (!dev)
102 return -ENODEV;
103
104 switch (len) {
105 case 1:
106 err = get_user(byte, (u8 __user *)buf);
107 if (err)
108 break;
109 err = pci_user_write_config_byte(dev, off, byte);
110 if (err)
111 err = -EIO;
112 break;
113
114 case 2:
115 err = get_user(word, (u16 __user *)buf);
116 if (err)
117 break;
118 err = pci_user_write_config_word(dev, off, word);
119 if (err)
120 err = -EIO;
121 break;
122
123 case 4:
124 err = get_user(dword, (u32 __user *)buf);
125 if (err)
126 break;
127 err = pci_user_write_config_dword(dev, off, dword);
128 if (err)
129 err = -EIO;
130 break;
131
132 default:
133 err = -EINVAL;
134 break;
135 }
136 pci_dev_put(dev);
137 return err;
138}