1 /* 2 * The PCI Library -- Configuration Access via /sys/bus/pci 3 * 4 * Copyright (c) 2003 Matthew Wilcox <[email protected]> 5 * Copyright (c) 1997--2003 Martin Mares <[email protected]> 6 * 7 * Can be freely distributed and used under the terms of the GNU GPL. 8 */ 9 10 #define _GNU_SOURCE 11 12 #include <stdio.h> 13 #include <stdlib.h> 14 #include <string.h> 15 #include <stdarg.h> 16 #include <unistd.h> 17 #include <errno.h> 18 #include <dirent.h> 19 #include <fcntl.h> 20 #include <sys/types.h> 21 22 #include "internal.h" 23 #include "pread.h" 24 25 static void 26 sysfs_config(struct pci_access *a) 27 { 28 a->method_params[PCI_ACCESS_SYS_BUS_PCI] = PCI_PATH_SYS_BUS_PCI; 29 } 30 31 static inline char * 32 sysfs_name(struct pci_access *a) 33 { 34 return a->method_params[PCI_ACCESS_SYS_BUS_PCI]; 35 } 36 37 static int 38 sysfs_detect(struct pci_access *a) 39 { 40 if (access(sysfs_name(a), R_OK)) 41 { 42 a->debug("...cannot open %s", sysfs_name(a)); 43 return 0; 44 } 45 a->debug("...using %s", sysfs_name(a)); 46 return 1; 47 } 48 49 static void 50 sysfs_init(struct pci_access *a) 51 { 52 a->fd = -1; 53 } 54 55 static void 56 sysfs_cleanup(struct pci_access *a) 57 { 58 if (a->fd >= 0) 59 { 60 close(a->fd); 61 a->fd = -1; 62 } 63 } 64 65 #define OBJNAMELEN 1024 66 static void 67 sysfs_obj_name(struct pci_dev *d, char *object, char *buf) 68 { 69 int n = snprintf(buf, OBJNAMELEN, "%s/devices/%04x:%02x:%02x.%d/%s", 70 sysfs_name(d->access), d->domain, d->bus, d->dev, d->func, object); 71 if (n < 0 || n >= OBJNAMELEN) 72 d->access->error("File name too long"); 73 } 74 75 static int 76 sysfs_get_value(struct pci_dev *d, char *object) 77 { 78 struct pci_access *a = d->access; 79 int fd, n; 80 char namebuf[OBJNAMELEN], buf[256]; 81 82 sysfs_obj_name(d, object, namebuf); 83 fd = open(namebuf, O_RDONLY); 84 if (fd < 0) 85 a->error("Cannot open %s: %s", namebuf, strerror(errno)); 86 n = read(fd, buf, sizeof(buf)); 87 close(fd); 88 if (n < 0) 89 a->error("Error reading %s: %s", namebuf, strerror(errno)); 90 if (n >= (int) sizeof(buf)) 91 a->error("Value in %s too long", namebuf); 92 buf[n] = 0; 93 return strtol(buf, NULL, 0); 94 } 95 96 static void 97 sysfs_get_resources(struct pci_dev *d) 98 { 99 struct pci_access *a = d->access; 100 char namebuf[OBJNAMELEN], buf[256]; 101 FILE *file; 102 int i; 103 104 sysfs_obj_name(d, "resource", namebuf); 105 file = fopen(namebuf, "r"); 106 if (!file) 107 a->error("Cannot open %s: %s", namebuf, strerror(errno)); 108 for (i = 0; i < 7; i++) 109 { 110 unsigned long long start, end, size; 111 if (!fgets(buf, sizeof(buf), file)) 112 break; 113 if (sscanf(buf, "%llx %llx", &start, &end) != 2) 114 a->error("Syntax error in %s", namebuf); 115 if (start != (unsigned long long)(pciaddr_t) start || 116 end != (unsigned long long)(pciaddr_t) end) 117 { 118 a->warning("Resource %d in %s has a 64-bit address, ignoring", i, namebuf); 119 start = end = 0; 120 } 121 if (start) 122 size = end - start + 1; 123 else 124 size = 0; 125 if (i < 6) 126 { 127 d->base_addr[i] = start; 128 d->size[i] = size; 129 } 130 else 131 { 132 d->rom_base_addr = start; 133 d->rom_size = size; 134 } 135 } 136 fclose(file); 137 } 138 139 static void sysfs_scan(struct pci_access *a) 140 { 141 char dirname[1024]; 142 DIR *dir; 143 struct dirent *entry; 144 int n; 145 146 n = snprintf(dirname, sizeof(dirname), "%s/devices", sysfs_name(a)); 147 if (n < 0 || n >= (int) sizeof(dirname)) 148 a->error("Directory name too long"); 149 dir = opendir(dirname); 150 if (!dir) 151 a->error("Cannot open %s", dirname); 152 while ((entry = readdir(dir))) 153 { 154 struct pci_dev *d; 155 unsigned int dom, bus, dev, func; 156 157 /* ".", ".." or a special non-device perhaps */ 158 if (entry->d_name[0] == '.') 159 continue; 160 161 d = pci_alloc_dev(a); 162 if (sscanf(entry->d_name, "%x:%x:%x.%d", &dom, &bus, &dev, &func) < 4) 163 a->error("sysfs_scan: Couldn't parse entry name %s", entry->d_name); 164 d->domain = dom; 165 d->bus = bus; 166 d->dev = dev; 167 d->func = func; 168 if (!a->buscentric) 169 { 170 sysfs_get_resources(d); 171 d->irq = sysfs_get_value(d, "irq"); 172 d->known_fields = PCI_FILL_IRQ | PCI_FILL_BASES | PCI_FILL_ROM_BASE | PCI_FILL_SIZES; 173 #if 0 174 /* 175 * We prefer reading these from the config registers, it's faster. 176 * However, it would be possible and maybe even useful to hack the kernel 177 * to believe that some device has a different ID. If you do it, just 178 * enable this piece of code. --mj 179 */ 180 d->vendor_id = sysfs_get_value(d, "vendor"); 181 d->device_id = sysfs_get_value(d, "device"); 182 d->known_fields |= PCI_FILL_IDENT; 183 #endif 184 } 185 pci_link_dev(a, d); 186 } 187 closedir(dir); 188 } 189 190 static int 191 sysfs_setup(struct pci_dev *d, int rw) 192 { 193 struct pci_access *a = d->access; 194 195 if (a->cached_dev != d || a->fd_rw < rw) 196 { 197 char namebuf[OBJNAMELEN]; 198 if (a->fd >= 0) 199 close(a->fd); 200 sysfs_obj_name(d, "config", namebuf); 201 a->fd_rw = a->writeable || rw; 202 a->fd = open(namebuf, a->fd_rw ? O_RDWR : O_RDONLY); 203 if (a->fd < 0) 204 a->warning("Cannot open %s", namebuf); 205 a->cached_dev = d; 206 a->fd_pos = 0; 207 } 208 return a->fd; 209 } 210 211 static int sysfs_read(struct pci_dev *d, int pos, byte *buf, int len) 212 { 213 int fd = sysfs_setup(d, 0); 214 int res; 215 216 if (fd < 0) 217 return 0; 218 res = do_read(d, fd, buf, len, pos); 219 if (res < 0) 220 { 221 d->access->warning("sysfs_read: read failed: %s", strerror(errno)); 222 return 0; 223 } 224 else if (res != len) 225 return 0; 226 return 1; 227 } 228 229 static int sysfs_write(struct pci_dev *d, int pos, byte *buf, int len) 230 { 231 int fd = sysfs_setup(d, 1); 232 int res; 233 234 if (fd < 0) 235 return 0; 236 res = do_write(d, fd, buf, len, pos); 237 if (res < 0) 238 { 239 d->access->warning("sysfs_write: write failed: %s", strerror(errno)); 240 return 0; 241 } 242 else if (res != len) 243 { 244 d->access->warning("sysfs_write: tried to write %d bytes at %d, but only %d succeeded", len, pos, res); 245 return 0; 246 } 247 return 1; 248 } 249 250 static void sysfs_cleanup_dev(struct pci_dev *d) 251 { 252 struct pci_access *a = d->access; 253 254 if (a->cached_dev == d) 255 { 256 a->cached_dev = NULL; 257 close(a->fd); 258 a->fd = -1; 259 } 260 } 261 262 struct pci_methods pm_linux_sysfs = { 263 "Linux-sysfs", 264 sysfs_config, 265 sysfs_detect, 266 sysfs_init, 267 sysfs_cleanup, 268 sysfs_scan, 269 pci_generic_fill_info, 270 sysfs_read, 271 sysfs_write, 272 NULL, /* init_dev */ 273 sysfs_cleanup_dev 274 }; 275