1 /*
2 * The PCI Library -- Configuration Access via /proc/bus/pci
3 *
4 * Copyright (c) 1997--2023 Martin Mares <[email protected]>
5 *
6 * Can be freely distributed and used under the terms of the GNU GPL v2+.
7 *
8 * SPDX-License-Identifier: GPL-2.0-or-later
9 */
10
11 #define _GNU_SOURCE
12
13 #include <stdio.h>
14 #include <string.h>
15 #include <unistd.h>
16 #include <ctype.h>
17 #include <errno.h>
18 #include <fcntl.h>
19 #include <sys/types.h>
20
21 #include "internal.h"
22
23 static void
proc_config(struct pci_access * a)24 proc_config(struct pci_access *a)
25 {
26 pci_define_param(a, "proc.path", PCI_PATH_PROC_BUS_PCI, "Path to the procfs bus tree");
27 }
28
29 static int
proc_detect(struct pci_access * a)30 proc_detect(struct pci_access *a)
31 {
32 char *name = pci_get_param(a, "proc.path");
33
34 if (access(name, R_OK))
35 {
36 a->warning("Cannot open %s", name);
37 return 0;
38 }
39 a->debug("...using %s", name);
40 return 1;
41 }
42
43 static void
proc_init(struct pci_access * a)44 proc_init(struct pci_access *a)
45 {
46 a->fd = -1;
47 }
48
49 static void
proc_cleanup(struct pci_access * a)50 proc_cleanup(struct pci_access *a)
51 {
52 if (a->fd >= 0)
53 {
54 close(a->fd);
55 a->fd = -1;
56 }
57 }
58
59 static void
proc_scan(struct pci_access * a)60 proc_scan(struct pci_access *a)
61 {
62 FILE *f;
63 char buf[512];
64
65 if (snprintf(buf, sizeof(buf), "%s/devices", pci_get_param(a, "proc.path")) == sizeof(buf))
66 a->error("File name too long");
67 f = fopen(buf, "r");
68 if (!f)
69 a->error("Cannot open %s", buf);
70 while (fgets(buf, sizeof(buf)-1, f))
71 {
72 struct pci_dev *d = pci_alloc_dev(a);
73 unsigned int dfn, vend, cnt, known;
74 char *driver;
75 int offset;
76
77 #define F " " PCIADDR_T_FMT
78 cnt = sscanf(buf, "%x %x %x" F F F F F F F F F F F F F F "%n",
79 &dfn,
80 &vend,
81 &d->irq,
82 &d->base_addr[0],
83 &d->base_addr[1],
84 &d->base_addr[2],
85 &d->base_addr[3],
86 &d->base_addr[4],
87 &d->base_addr[5],
88 &d->rom_base_addr,
89 &d->size[0],
90 &d->size[1],
91 &d->size[2],
92 &d->size[3],
93 &d->size[4],
94 &d->size[5],
95 &d->rom_size,
96 &offset);
97 #undef F
98 if (cnt != 9 && cnt != 10 && cnt != 17)
99 a->error("proc: parse error (read only %d items)", cnt);
100 d->bus = dfn >> 8U;
101 d->dev = PCI_SLOT(dfn & 0xff);
102 d->func = PCI_FUNC(dfn & 0xff);
103 d->vendor_id = vend >> 16U;
104 d->device_id = vend & 0xffff;
105 known = 0;
106 if (!a->buscentric)
107 {
108 known |= PCI_FILL_IDENT | PCI_FILL_IRQ | PCI_FILL_BASES;
109 if (cnt >= 10)
110 known |= PCI_FILL_ROM_BASE;
111 if (cnt >= 17)
112 known |= PCI_FILL_SIZES;
113 }
114 if (cnt >= 17)
115 {
116 while (buf[offset] && isspace(buf[offset]))
117 ++offset;
118 driver = &buf[offset];
119 while (buf[offset] && !isspace(buf[offset]))
120 ++offset;
121 buf[offset] = '\0';
122 if (driver[0])
123 {
124 pci_set_property(d, PCI_FILL_DRIVER, driver);
125 known |= PCI_FILL_DRIVER;
126 }
127 }
128 d->known_fields = known;
129 pci_link_dev(a, d);
130 }
131 fclose(f);
132 }
133
134 static int
proc_setup(struct pci_dev * d,int rw)135 proc_setup(struct pci_dev *d, int rw)
136 {
137 struct pci_access *a = d->access;
138
139 if (a->cached_dev != d || a->fd_rw < rw)
140 {
141 char buf[1024];
142 int e;
143 if (a->fd >= 0)
144 close(a->fd);
145 e = snprintf(buf, sizeof(buf), "%s/%02x/%02x.%d",
146 pci_get_param(a, "proc.path"),
147 d->bus, d->dev, d->func);
148 if (e < 0 || e >= (int) sizeof(buf))
149 a->error("File name too long");
150 a->fd_rw = a->writeable || rw;
151 a->fd = open(buf, a->fd_rw ? O_RDWR : O_RDONLY);
152 if (a->fd < 0)
153 {
154 e = snprintf(buf, sizeof(buf), "%s/%04x:%02x/%02x.%d",
155 pci_get_param(a, "proc.path"),
156 d->domain, d->bus, d->dev, d->func);
157 if (e < 0 || e >= (int) sizeof(buf))
158 a->error("File name too long");
159 a->fd = open(buf, a->fd_rw ? O_RDWR : O_RDONLY);
160 }
161 if (a->fd < 0)
162 a->warning("Cannot open %s", buf);
163 a->cached_dev = d;
164 }
165 return a->fd;
166 }
167
168 static int
proc_read(struct pci_dev * d,int pos,byte * buf,int len)169 proc_read(struct pci_dev *d, int pos, byte *buf, int len)
170 {
171 int fd = proc_setup(d, 0);
172 int res;
173
174 if (fd < 0)
175 return 0;
176 res = pread(fd, buf, len, pos);
177 if (res < 0)
178 {
179 d->access->warning("proc_read: read failed: %s", strerror(errno));
180 return 0;
181 }
182 else if (res != len)
183 return 0;
184 return 1;
185 }
186
187 static int
proc_write(struct pci_dev * d,int pos,byte * buf,int len)188 proc_write(struct pci_dev *d, int pos, byte *buf, int len)
189 {
190 int fd = proc_setup(d, 1);
191 int res;
192
193 if (fd < 0)
194 return 0;
195 res = pwrite(fd, buf, len, pos);
196 if (res < 0)
197 {
198 d->access->warning("proc_write: write failed: %s", strerror(errno));
199 return 0;
200 }
201 else if (res != len)
202 {
203 d->access->warning("proc_write: tried to write %d bytes at %d, but only %d succeeded", len, pos, res);
204 return 0;
205 }
206 return 1;
207 }
208
209 static void
proc_cleanup_dev(struct pci_dev * d)210 proc_cleanup_dev(struct pci_dev *d)
211 {
212 if (d->access->cached_dev == d)
213 d->access->cached_dev = NULL;
214 }
215
216 struct pci_methods pm_linux_proc = {
217 .name = "linux-proc",
218 .help = "The proc file system on Linux",
219 .config = proc_config,
220 .detect = proc_detect,
221 .init = proc_init,
222 .cleanup = proc_cleanup,
223 .scan = proc_scan,
224 .fill_info = pci_generic_fill_info,
225 .read = proc_read,
226 .write = proc_write,
227 .cleanup_dev = proc_cleanup_dev,
228 };
229