lib/proc.c

   1 /*
   2  *      The PCI Library -- Configuration Access via /proc/bus/pci
   3  *
   4  *      Copyright (c) 1997--2003 Martin Mares <mj@ucw.cz>
   5  *
   6  *      Can be freely distributed and used under the terms of the GNU GPL.
   7  */
   8
   9 #define _GNU_SOURCE
  10
  11 #include <stdio.h>
  12 #include <string.h>
  13 #include <unistd.h>
  14 #include <errno.h>
  15 #include <fcntl.h>
  16 #include <sys/types.h>
  17
  18 #include "internal.h"
  19 #include "pread.h"
  20
  21 static void
  22 proc_config(struct pci_access *a)
  23 {
  24   pci_define_param(a, "proc.path", PCI_PATH_PROC_BUS_PCI, "Path to the procfs bus tree");
  25 }
  26
  27 static int
  28 proc_detect(struct pci_access *a)
  29 {
  30   char *name = pci_get_param(a, "proc.path");
  31
  32   if (access(name, R_OK))
  33     {
  34       a->warning("Cannot open %s", name);
  35       return 0;
  36     }
  37   a->debug("...using %s", name);
  38   return 1;
  39 }
  40
  41 static void
  42 proc_init(struct pci_access *a)
  43 {
  44   a->fd = -1;
  45 }
  46
  47 static void
  48 proc_cleanup(struct pci_access *a)
  49 {
  50   if (a->fd >= 0)
  51     {
  52       close(a->fd);
  53       a->fd = -1;
  54     }
  55 }
  56
  57 static void
  58 proc_scan(struct pci_access *a)
  59 {
  60   FILE *f;
  61   char buf[512];
  62
  63   if (snprintf(buf, sizeof(buf), "%s/devices", pci_get_param(a, "proc.path")) == sizeof(buf))
  64     a->error("File name too long");
  65   f = fopen(buf, "r");
  66   if (!f)
  67     a->error("Cannot open %s", buf);
  68   while (fgets(buf, sizeof(buf)-1, f))
  69     {
  70       struct pci_dev *d = pci_alloc_dev(a);
  71       unsigned int dfn, vend, cnt, known;
  72
  73 #define F " " PCIADDR_T_FMT
  74       cnt = sscanf(buf, "%x %x %x" F F F F F F F F F F F F F F,
  75              &dfn,
  76              &vend,
  77              &d->irq,
  78              &d->base_addr[0],
  79              &d->base_addr[1],
  80              &d->base_addr[2],
  81              &d->base_addr[3],
  82              &d->base_addr[4],
  83              &d->base_addr[5],
  84              &d->rom_base_addr,
  85              &d->size[0],
  86              &d->size[1],
  87              &d->size[2],
  88              &d->size[3],
  89              &d->size[4],
  90              &d->size[5],
  91              &d->rom_size);
  92 #undef F
  93       if (cnt != 9 && cnt != 10 && cnt != 17)
  94         a->error("proc: parse error (read only %d items)", cnt);
  95       d->bus = dfn >> 8U;
  96       d->dev = PCI_SLOT(dfn & 0xff);
  97       d->func = PCI_FUNC(dfn & 0xff);
  98       d->vendor_id = vend >> 16U;
  99       d->device_id = vend & 0xffff;
 100       known = 0;
 101       if (!a->buscentric)
 102         {
 103           known |= PCI_FILL_IDENT | PCI_FILL_IRQ | PCI_FILL_BASES;
 104           if (cnt >= 10)
 105             known |= PCI_FILL_ROM_BASE;
 106           if (cnt >= 17)
 107             known |= PCI_FILL_SIZES;
 108         }
 109       d->known_fields = known;
 110       pci_link_dev(a, d);
 111     }
 112   fclose(f);
 113 }
 114
 115 static int
 116 proc_setup(struct pci_dev *d, int rw)
 117 {
 118   struct pci_access *a = d->access;
 119
 120   if (a->cached_dev != d || a->fd_rw < rw)
 121     {
 122       char buf[1024];
 123       int e;
 124       if (a->fd >= 0)
 125         close(a->fd);
 126       e = snprintf(buf, sizeof(buf), "%s/%02x/%02x.%d",
 127                    pci_get_param(a, "proc.path"),
 128                    d->bus, d->dev, d->func);
 129       if (e < 0 || e >= (int) sizeof(buf))
 130         a->error("File name too long");
 131       a->fd_rw = a->writeable || rw;
 132       a->fd = open(buf, a->fd_rw ? O_RDWR : O_RDONLY);
 133       if (a->fd < 0)
 134         {
 135           e = snprintf(buf, sizeof(buf), "%s/%04x:%02x/%02x.%d",
 136                        pci_get_param(a, "proc.path"),
 137                        d->domain, d->bus, d->dev, d->func);
 138           if (e < 0 || e >= (int) sizeof(buf))
 139             a->error("File name too long");
 140           a->fd = open(buf, a->fd_rw ? O_RDWR : O_RDONLY);
 141         }
 142       if (a->fd < 0)
 143         a->warning("Cannot open %s", buf);
 144       a->cached_dev = d;
 145       a->fd_pos = 0;
 146     }
 147   return a->fd;
 148 }
 149
 150 static int
 151 proc_read(struct pci_dev *d, int pos, byte *buf, int len)
 152 {
 153   int fd = proc_setup(d, 0);
 154   int res;
 155
 156   if (fd < 0)
 157     return 0;
 158   res = do_read(d, fd, buf, len, pos);
 159   if (res < 0)
 160     {
 161       d->access->warning("proc_read: read failed: %s", strerror(errno));
 162       return 0;
 163     }
 164   else if (res != len)
 165     return 0;
 166   return 1;
 167 }
 168
 169 static int
 170 proc_write(struct pci_dev *d, int pos, byte *buf, int len)
 171 {
 172   int fd = proc_setup(d, 1);
 173   int res;
 174
 175   if (fd < 0)
 176     return 0;
 177   res = do_write(d, fd, buf, len, pos);
 178   if (res < 0)
 179     {
 180       d->access->warning("proc_write: write failed: %s", strerror(errno));
 181       return 0;
 182     }
 183   else if (res != len)
 184     {
 185       d->access->warning("proc_write: tried to write %d bytes at %d, but only %d succeeded", len, pos, res);
 186       return 0;
 187     }
 188   return 1;
 189 }
 190
 191 static void
 192 proc_cleanup_dev(struct pci_dev *d)
 193 {
 194   if (d->access->cached_dev == d)
 195     d->access->cached_dev = NULL;
 196 }
 197
 198 struct pci_methods pm_linux_proc = {
 199   "linux-proc",
 200   "The proc file system on Linux",
 201   proc_config,
 202   proc_detect,
 203   proc_init,
 204   proc_cleanup,
 205   proc_scan,
 206   pci_generic_fill_info,
 207   proc_read,
 208   proc_write,
 209   NULL,                                 /* read_vpd */
 210   NULL,                                 /* init_dev */
 211   proc_cleanup_dev
 212 };