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 <idr@us.ibm.com>
34 */
35 #ifdef HAVE_CONFIG_H
36 #include "config.h"
37 #endif
38
39 #include <stdlib.h>
40 #include <string.h>
41 #include <stdio.h>
42 #include <unistd.h>
43 #include <sys/types.h>
44 #include <sys/stat.h>
45 #include <fcntl.h>
46 #include <sys/mman.h>
47 #include <dirent.h>
48 #include <errno.h>
49
50 #include "pciaccess.h"
51 #include "pciaccess_private.h"
52 #include "linux_devmem.h"
53
54 /**
55 * Read a device's expansion ROM using /dev/mem.
56 *
57 * \note
58 * This function could probably be used, as-is, on other platforms that have
59 * a /dev/mem interface.
60 *
61 * \bugs
62 * Before using the VGA special case code, this function should check that
63 * VGA access are routed to the device. Right?
64 */
65 _pci_hidden int
pci_device_linux_devmem_read_rom(struct pci_device * dev,void * buffer)66 pci_device_linux_devmem_read_rom(struct pci_device *dev, void *buffer)
67 {
68 struct pci_device_private *priv = (struct pci_device_private *) dev;
69 int fd;
70 int err = 0;
71 uint32_t rom_base_tmp;
72 pciaddr_t rom_base;
73 pciaddr_t rom_size;
74 int PCI_ROM;
75
76
77 /* Handle some special cases of legacy devices.
78 */
79 if (priv->base.rom_size == 0) {
80 /* VGA ROMs are supposed to be at 0xC0000.
81 */
82 if ((priv->base.device_class & 0x00ffff00) == 0x000030000) {
83 rom_base = 0x000C0000;
84 rom_size = 0x00010000;
85 PCI_ROM = 0;
86 }
87 else {
88 /* "Function not implemented."
89 */
90 return ENOSYS;
91 }
92 }
93 else {
94 rom_base = priv->rom_base;
95 rom_size = priv->base.rom_size;
96 PCI_ROM = 1;
97 }
98
99
100
101 /* Enable the device's ROM.
102 */
103 if (PCI_ROM) {
104 err = pci_device_cfg_read_u32(& priv->base, & rom_base_tmp, 48);
105 if (err) {
106 return err;
107 }
108
109 if ((rom_base_tmp & 0x000000001) == 0) {
110 err = pci_device_cfg_write_u32(& priv->base,
111 rom_base_tmp | 1, 48);
112 if (err) {
113 return err;
114 }
115 }
116 }
117
118
119 /* Read the portion of /dev/mem that corresponds to the device's ROM.
120 */
121 fd = open("/dev/mem", O_RDONLY, 0);
122 if (fd < 0) {
123 err = errno;
124 }
125 else {
126 size_t bytes;
127
128 for (bytes = 0; bytes < rom_size; /* empty */) {
129 const ssize_t got = pread(fd, buffer, rom_size - bytes,
130 rom_base + bytes);
131 if (got == -1) {
132 err = errno;
133 break;
134 }
135
136 bytes += got;
137 }
138
139 close(fd);
140 }
141
142
143 /* Disable the device's ROM.
144 */
145 if (PCI_ROM && ((rom_base_tmp & 0x000000001) == 0)) {
146 const int tmp_err = pci_device_cfg_write_u32(& priv->base,
147 rom_base_tmp, 48);
148
149 /* Prefer to return the first error that occurred.
150 */
151 if (err == 0) {
152 err = tmp_err;
153 }
154 }
155
156 return err;
157 }
158