1 /*
2 * (C) Copyright IBM Corporation 2007
3 * All Rights Reserved.
4 *
5 * Permission is hereby granted, free of charge, to any person obtaining a
6 * copy of this software and associated documentation files (the "Software"),
7 * to deal in the Software without restriction, including without limitation
8 * on the rights to use, copy, modify, merge, publish, distribute, sub
9 * license, and/or sell copies of the Software, and to permit persons to whom
10 * the Software is furnished to do so, subject to the following conditions:
11 *
12 * The above copyright notice and this permission notice (including the next
13 * paragraph) shall be included in all copies or substantial portions of the
14 * Software.
15 *
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
19 * IBM AND/OR THEIR SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
21 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
22 * DEALINGS IN THE SOFTWARE.
23 */
24
25 /**
26 * \file linux_devmem.c
27 * Access PCI subsystem using Linux's the old /dev/mem interface.
28 *
29 * \note
30 * This is currently just a skeleton. It only includes the /dev/mem based
31 * function for reading the device ROM.
32 *
33 * \author Ian Romanick <[email protected]>
34 */
35
36 #define _GNU_SOURCE
37
38 #include <stdlib.h>
39 #include <string.h>
40 #include <stdio.h>
41 #include <unistd.h>
42 #include <sys/types.h>
43 #include <sys/stat.h>
44 #include <fcntl.h>
45 #include <sys/mman.h>
46 #include <dirent.h>
47 #include <errno.h>
48
49 #include "pciaccess.h"
50 #include "pciaccess_private.h"
51 #include "linux_devmem.h"
52
53 /**
54 * Read a device's expansion ROM using /dev/mem.
55 *
56 * \note
57 * This function could probably be used, as-is, on other platforms that have
58 * a /dev/mem interface.
59 *
60 * \bugs
61 * Before using the VGA special case code, this function should check that
62 * VGA access are routed to the device. Right?
63 */
64 _pci_hidden int
pci_device_linux_devmem_read_rom(struct pci_device * dev,void * buffer)65 pci_device_linux_devmem_read_rom(struct pci_device *dev, void *buffer)
66 {
67 struct pci_device_private *priv = (struct pci_device_private *) dev;
68 int fd;
69 int err = 0;
70 uint32_t rom_base_tmp;
71 pciaddr_t rom_base;
72 pciaddr_t rom_size;
73 int PCI_ROM;
74
75
76 /* Handle some special cases of legacy devices.
77 */
78 if (priv->base.rom_size == 0) {
79 /* VGA ROMs are supposed to be at 0xC0000.
80 */
81 if ((priv->base.device_class & 0x00ffff00) == 0x000030000) {
82 rom_base = 0x000C0000;
83 rom_size = 0x00010000;
84 PCI_ROM = 0;
85 }
86 else {
87 /* "Function not implemented."
88 */
89 return ENOSYS;
90 }
91 }
92 else {
93 rom_base = priv->rom_base;
94 rom_size = priv->base.rom_size;
95 PCI_ROM = 1;
96 }
97
98
99
100 /* Enable the device's ROM.
101 */
102 if (PCI_ROM) {
103 err = pci_device_cfg_read_u32(& priv->base, & rom_base_tmp, 48);
104 if (err) {
105 return err;
106 }
107
108 if ((rom_base_tmp & 0x000000001) == 0) {
109 err = pci_device_cfg_write_u32(& priv->base,
110 rom_base_tmp | 1, 48);
111 if (err) {
112 return err;
113 }
114 }
115 }
116
117
118 /* Read the portion of /dev/mem that corresponds to the device's ROM.
119 */
120 fd = open("/dev/mem", O_RDONLY, 0);
121 if (fd < 0) {
122 err = errno;
123 }
124 else {
125 size_t bytes;
126
127 for (bytes = 0; bytes < rom_size; /* empty */) {
128 const ssize_t got = pread(fd, buffer, rom_size - bytes,
129 rom_base + bytes);
130 if (got == -1) {
131 err = errno;
132 break;
133 }
134
135 bytes += got;
136 }
137
138 close(fd);
139 }
140
141
142 /* Disable the device's ROM.
143 */
144 if (PCI_ROM && ((rom_base_tmp & 0x000000001) == 0)) {
145 const int tmp_err = pci_device_cfg_write_u32(& priv->base,
146 rom_base_tmp, 48);
147
148 /* Prefer to return the first error that occurred.
149 */
150 if (err == 0) {
151 err = tmp_err;
152 }
153 }
154
155 return err;
156 }
157