[thirdparty/pciutils.git] / lib / sysfs.c

/*
 *	The PCI Library -- Configuration Access via /sys/bus/pci
 *
 *	Copyright (c) 2003 Matthew Wilcox <matthew@wil.cx>
 *	Copyright (c) 1997--2008 Martin Mares <mj@ucw.cz>
 *
 *	Can be freely distributed and used under the terms of the GNU GPL.
 */

#define _GNU_SOURCE

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdarg.h>
#include <unistd.h>
#include <errno.h>
#include <dirent.h>
#include <fcntl.h>
#include <sys/types.h>

#include "internal.h"
#include "pread.h"

static void
sysfs_config(struct pci_access *a)
{
  pci_define_param(a, "sysfs.path", PCI_PATH_SYS_BUS_PCI, "Path to the sysfs device tree");
}

static inline char *
sysfs_name(struct pci_access *a)
{
  return pci_get_param(a, "sysfs.path");
}

static int
sysfs_detect(struct pci_access *a)
{
  if (access(sysfs_name(a), R_OK))
    {
      a->debug("...cannot open %s", sysfs_name(a));
      return 0;
    }
  a->debug("...using %s", sysfs_name(a));
  return 1;
}

static void
sysfs_init(struct pci_access *a)
{
  a->fd = -1;
  a->fd_vpd = -1;
}

static void
sysfs_flush_cache(struct pci_access *a)
{
  if (a->fd >= 0)
    {
      close(a->fd);
      a->fd = -1;
    }
  if (a->fd_vpd >= 0)
    {
      close(a->fd_vpd);
      a->fd_vpd = -1;
    }
  a->cached_dev = NULL;
}

static void
sysfs_cleanup(struct pci_access *a)
{
  sysfs_flush_cache(a);
}

#define OBJNAMELEN 1024
static void
sysfs_obj_name(struct pci_dev *d, char *object, char *buf)
{
  int n = snprintf(buf, OBJNAMELEN, "%s/devices/%04x:%02x:%02x.%d/%s",
		   sysfs_name(d->access), d->domain, d->bus, d->dev, d->func, object);
  if (n < 0 || n >= OBJNAMELEN)
    d->access->error("File name too long");
}

static int
sysfs_get_value(struct pci_dev *d, char *object)
{
  struct pci_access *a = d->access;
  int fd, n;
  char namebuf[OBJNAMELEN], buf[256];

  sysfs_obj_name(d, object, namebuf);
  fd = open(namebuf, O_RDONLY);
  if (fd < 0)
    a->error("Cannot open %s: %s", namebuf, strerror(errno));
  n = read(fd, buf, sizeof(buf));
  close(fd);
  if (n < 0)
    a->error("Error reading %s: %s", namebuf, strerror(errno));
  if (n >= (int) sizeof(buf))
    a->error("Value in %s too long", namebuf);
  buf[n] = 0;
  return strtol(buf, NULL, 0);
}

static void
sysfs_get_resources(struct pci_dev *d)
{
  struct pci_access *a = d->access;
  char namebuf[OBJNAMELEN], buf[256];
  FILE *file;
  int i;

  sysfs_obj_name(d, "resource", namebuf);
  file = fopen(namebuf, "r");
  if (!file)
    a->error("Cannot open %s: %s", namebuf, strerror(errno));
  for (i = 0; i < 7; i++)
    {
      unsigned long long start, end, size, flags;
      if (!fgets(buf, sizeof(buf), file))
	break;
      if (sscanf(buf, "%llx %llx %llx", &start, &end, &flags) != 3)
	a->error("Syntax error in %s", namebuf);
      if (start)
	size = end - start + 1;
      else
	size = 0;
      flags &= PCI_ADDR_FLAG_MASK;
      if (i < 6)
	{
	  d->base_addr[i] = start | flags;
	  d->size[i] = size;
	}
      else
	{
	  d->rom_base_addr = start | flags;
	  d->rom_size = size;
	}
    }
  fclose(file);
}

static void sysfs_scan(struct pci_access *a)
{
  char dirname[1024];
  DIR *dir;
  struct dirent *entry;
  int n;

  n = snprintf(dirname, sizeof(dirname), "%s/devices", sysfs_name(a));
  if (n < 0 || n >= (int) sizeof(dirname))
    a->error("Directory name too long");
  dir = opendir(dirname);
  if (!dir)
    a->error("Cannot open %s", dirname);
  while ((entry = readdir(dir)))
    {
      struct pci_dev *d;
      unsigned int dom, bus, dev, func;

      /* ".", ".." or a special non-device perhaps */
      if (entry->d_name[0] == '.')
	continue;

      d = pci_alloc_dev(a);
      if (sscanf(entry->d_name, "%x:%x:%x.%d", &dom, &bus, &dev, &func) < 4)
	a->error("sysfs_scan: Couldn't parse entry name %s", entry->d_name);
      d->domain = dom;
      d->bus = bus;
      d->dev = dev;
      d->func = func;
      if (!a->buscentric)
	{
	  sysfs_get_resources(d);
	  d->irq = sysfs_get_value(d, "irq");
	  /*
	   *  We could read these faster from the config registers, but we want to give
	   *  the kernel a chance to fix up ID's and especially classes of broken devices.
	   */
	  d->vendor_id = sysfs_get_value(d, "vendor");
	  d->device_id = sysfs_get_value(d, "device");
	  d->device_class = sysfs_get_value(d, "class") >> 8;
	  d->known_fields = PCI_FILL_IDENT | PCI_FILL_CLASS | PCI_FILL_IRQ | PCI_FILL_BASES | PCI_FILL_ROM_BASE | PCI_FILL_SIZES;
	}
      pci_link_dev(a, d);
    }
  closedir(dir);
}

static void
sysfs_fill_slots(struct pci_access *a)
{
  char dirname[1024];
  DIR *dir;
  struct dirent *entry;
  int n;

  n = snprintf(dirname, sizeof(dirname), "%s/slots", sysfs_name(a));
  if (n < 0 || n >= (int) sizeof(dirname))
    a->error("Directory name too long");
  dir = opendir(dirname);
  if (!dir)
    return;

  while (entry = readdir(dir))
    {
      char namebuf[OBJNAMELEN], buf[16];
      FILE *file;
      unsigned int dom, bus, dev;
      struct pci_dev *d;

      /* ".", ".." or a special non-device perhaps */
      if (entry->d_name[0] == '.')
	continue;

      n = snprintf(namebuf, OBJNAMELEN, "%s/%s/%s", dirname, entry->d_name, "address");
      if (n < 0 || n >= OBJNAMELEN)
	a->error("File name too long");
      file = fopen(namebuf, "r");
      /*
       * Old versions of Linux had a fakephp which didn't have an 'address'
       * file.  There's no useful information to be gleaned from these
       * devices, pretend they're not there.
       */
      if (!file)
	continue;

      if (!fgets(buf, sizeof(buf), file) || sscanf(buf, "%x:%x:%x", &dom, &bus, &dev) < 3)
	a->warning("sysfs_fill_slots: Couldn't parse entry address %s", buf);
      else
	{
	  for (d = a->devices; d; d = d->next)
	    if (dom == d->domain && bus == d->bus && dev == d->dev && !d->phy_slot)
	      {
		d->phy_slot = pci_malloc(a, strlen(entry->d_name) + 1);
		strcpy(d->phy_slot, entry->d_name);
	      }
	}
      fclose(file);
    }
  closedir(dir);
}

static int
sysfs_fill_info(struct pci_dev *d, int flags)
{
  if ((flags & PCI_FILL_PHYS_SLOT) && !(d->known_fields & PCI_FILL_PHYS_SLOT))
    {
      struct pci_dev *pd;
      sysfs_fill_slots(d->access);
      for (pd = d->access->devices; pd; pd = pd->next)
	pd->known_fields |= PCI_FILL_PHYS_SLOT;
    }
  return pci_generic_fill_info(d, flags);
}

/* Intent of the sysfs_setup() caller */
enum
  {
    SETUP_READ_CONFIG = 0,
    SETUP_WRITE_CONFIG = 1,
    SETUP_READ_VPD = 2
  };

static int
sysfs_setup(struct pci_dev *d, int intent)
{
  struct pci_access *a = d->access;
  char namebuf[OBJNAMELEN];

  if (a->cached_dev != d || (intent == SETUP_WRITE_CONFIG && !a->fd_rw))
    {
      sysfs_flush_cache(a);
      a->cached_dev = d;
    }

  if (intent == SETUP_READ_VPD)
    {
      if (a->fd_vpd < 0)
	{
	  sysfs_obj_name(d, "vpd", namebuf);
	  a->fd_vpd = open(namebuf, O_RDONLY);
	  /* No warning on error; vpd may be absent or accessible only to root */
	}
      return a->fd_vpd;
    }

  if (a->fd < 0)
    {
      sysfs_obj_name(d, "config", namebuf);
      a->fd_rw = a->writeable || intent == SETUP_WRITE_CONFIG;
      a->fd = open(namebuf, a->fd_rw ? O_RDWR : O_RDONLY);
      if (a->fd < 0)
	a->warning("Cannot open %s", namebuf);
      a->fd_pos = 0;
    }
  return a->fd;
}

static int sysfs_read(struct pci_dev *d, int pos, byte *buf, int len)
{
  int fd = sysfs_setup(d, SETUP_READ_CONFIG);
  int res;

  if (fd < 0)
    return 0;
  res = do_read(d, fd, buf, len, pos);
  if (res < 0)
    {
      d->access->warning("sysfs_read: read failed: %s", strerror(errno));
      return 0;
    }
  else if (res != len)
    return 0;
  return 1;
}

static int sysfs_write(struct pci_dev *d, int pos, byte *buf, int len)
{
  int fd = sysfs_setup(d, SETUP_WRITE_CONFIG);
  int res;

  if (fd < 0)
    return 0;
  res = do_write(d, fd, buf, len, pos);
  if (res < 0)
    {
      d->access->warning("sysfs_write: write failed: %s", strerror(errno));
      return 0;
    }
  else if (res != len)
    {
      d->access->warning("sysfs_write: tried to write %d bytes at %d, but only %d succeeded", len, pos, res);
      return 0;
    }
  return 1;
}

#ifdef PCI_HAVE_DO_READ

/* pread() is not available and do_read() only works for a single fd, so we
 * cannot implement read_vpd properly. */
static int sysfs_read_vpd(struct pci_dev *d, int pos, byte *buf, int len)
{
  return 0;
}

#else /* !PCI_HAVE_DO_READ */

static int sysfs_read_vpd(struct pci_dev *d, int pos, byte *buf, int len)
{
  int fd = sysfs_setup(d, SETUP_READ_VPD);
  int res;

  if (fd < 0)
    return 0;
  res = pread(fd, buf, len, pos);
  if (res < 0)
    {
      d->access->warning("sysfs_read_vpd: read failed: %s", strerror(errno));
      return 0;
    }
  else if (res != len)
    return 0;
  return 1;
}

#endif /* PCI_HAVE_DO_READ */

static void sysfs_cleanup_dev(struct pci_dev *d)
{
  struct pci_access *a = d->access;

  if (a->cached_dev == d)
    sysfs_flush_cache(a);
}

struct pci_methods pm_linux_sysfs = {
  "linux-sysfs",
  "The sys filesystem on Linux",
  sysfs_config,
  sysfs_detect,
  sysfs_init,
  sysfs_cleanup,
  sysfs_scan,
  sysfs_fill_info,
  sysfs_read,
  sysfs_write,
  sysfs_read_vpd,
  NULL,					/* init_dev */
  sysfs_cleanup_dev
};
Commit	Line	Data
11f7b31b MM	1	/*
	2	* The PCI Library -- Configuration Access via /sys/bus/pci
	3	*
535fca0e	4	* Copyright (c) 2003 Matthew Wilcox <matthew@wil.cx>
cb6ee324	5	* Copyright (c) 1997--2008 Martin Mares <mj@ucw.cz>
11f7b31b MM	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	{
cb6ee324	28	pci_define_param(a, "sysfs.path", PCI_PATH_SYS_BUS_PCI, "Path to the sysfs device tree");
11f7b31b MM	29	}
	30
	31	static inline char *
	32	sysfs_name(struct pci_access *a)
	33	{
cb6ee324	34	return pci_get_param(a, "sysfs.path");
11f7b31b MM	35	}
	36
	37	static int
	38	sysfs_detect(struct pci_access *a)
	39	{
	40	if (access(sysfs_name(a), R_OK))
	41	{
84c8d1bb	42	a->debug("...cannot open %s", sysfs_name(a));
11f7b31b MM	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;
07ad085d	53	a->fd_vpd = -1;
11f7b31b MM	54	}
	55
	56	static void
07ad085d	57	sysfs_flush_cache(struct pci_access *a)
11f7b31b MM	58	{
	59	if (a->fd >= 0)
	60	{
	61	close(a->fd);
	62	a->fd = -1;
	63	}
07ad085d MM	64	if (a->fd_vpd >= 0)
	65	{
	66	close(a->fd_vpd);
	67	a->fd_vpd = -1;
	68	}
	69	a->cached_dev = NULL;
	70	}
	71
	72	static void
	73	sysfs_cleanup(struct pci_access *a)
	74	{
	75	sysfs_flush_cache(a);
11f7b31b MM	76	}
	77
	78	#define OBJNAMELEN 1024
	79	static void
	80	sysfs_obj_name(struct pci_dev d, char object, char *buf)
	81	{
	82	int n = snprintf(buf, OBJNAMELEN, "%s/devices/%04x:%02x:%02x.%d/%s",
	83	sysfs_name(d->access), d->domain, d->bus, d->dev, d->func, object);
	84	if (n < 0 \|\| n >= OBJNAMELEN)
	85	d->access->error("File name too long");
	86	}
	87
	88	static int
	89	sysfs_get_value(struct pci_dev d, char object)
	90	{
	91	struct pci_access *a = d->access;
	92	int fd, n;
	93	char namebuf[OBJNAMELEN], buf[256];
	94
	95	sysfs_obj_name(d, object, namebuf);
	96	fd = open(namebuf, O_RDONLY);
	97	if (fd < 0)
	98	a->error("Cannot open %s: %s", namebuf, strerror(errno));
	99	n = read(fd, buf, sizeof(buf));
	100	close(fd);
	101	if (n < 0)
	102	a->error("Error reading %s: %s", namebuf, strerror(errno));
	103	if (n >= (int) sizeof(buf))
	104	a->error("Value in %s too long", namebuf);
	105	buf[n] = 0;
	106	return strtol(buf, NULL, 0);
	107	}
	108
	109	static void
	110	sysfs_get_resources(struct pci_dev *d)
	111	{
	112	struct pci_access *a = d->access;
	113	char namebuf[OBJNAMELEN], buf[256];
	114	FILE *file;
	115	int i;
	116
	117	sysfs_obj_name(d, "resource", namebuf);
	118	file = fopen(namebuf, "r");
	119	if (!file)
	120	a->error("Cannot open %s: %s", namebuf, strerror(errno));
9bb4b4ea	121	for (i = 0; i < 7; i++)
11f7b31b	122	{
6d143c32	123	unsigned long long start, end, size, flags;
11f7b31b MM	124	if (!fgets(buf, sizeof(buf), file))
11f7b31b MM	125	break;
6d143c32	126	if (sscanf(buf, "%llx %llx %llx", &start, &end, &flags) != 3)
11f7b31b	127	a->error("Syntax error in %s", namebuf);
11f7b31b MM	128	if (start)
	129	size = end - start + 1;
	130	else
	131	size = 0;
6d143c32	132	flags &= PCI_ADDR_FLAG_MASK;
9bb4b4ea	133	if (i < 6)
11f7b31b	134	{
6d143c32	135	d->base_addr[i] = start \| flags;
11f7b31b MM	136	d->size[i] = size;
	137	}
	138	else
	139	{
6d143c32	140	d->rom_base_addr = start \| flags;
11f7b31b MM	141	d->rom_size = size;
	142	}
	143	}
	144	fclose(file);
	145	}
	146
	147	static void sysfs_scan(struct pci_access *a)
	148	{
	149	char dirname[1024];
	150	DIR *dir;
	151	struct dirent *entry;
	152	int n;
	153
	154	n = snprintf(dirname, sizeof(dirname), "%s/devices", sysfs_name(a));
	155	if (n < 0 \|\| n >= (int) sizeof(dirname))
	156	a->error("Directory name too long");
	157	dir = opendir(dirname);
	158	if (!dir)
	159	a->error("Cannot open %s", dirname);
	160	while ((entry = readdir(dir)))
	161	{
	162	struct pci_dev *d;
	163	unsigned int dom, bus, dev, func;
	164
	165	/* ".", ".." or a special non-device perhaps */
	166	if (entry->d_name[0] == '.')
	167	continue;
	168
	169	d = pci_alloc_dev(a);
	170	if (sscanf(entry->d_name, "%x:%x:%x.%d", &dom, &bus, &dev, &func) < 4)
	171	a->error("sysfs_scan: Couldn't parse entry name %s", entry->d_name);
	172	d->domain = dom;
	173	d->bus = bus;
	174	d->dev = dev;
	175	d->func = func;
11f7b31b MM	176	if (!a->buscentric)
	177	{
	178	sysfs_get_resources(d);
84c8d1bb	179	d->irq = sysfs_get_value(d, "irq");
84c8d1bb	180	/*
c2b144ef MM	181	* We could read these faster from the config registers, but we want to give
c2b144ef MM	182	* the kernel a chance to fix up ID's and especially classes of broken devices.
84c8d1bb	183	*/
11f7b31b MM	184	d->vendor_id = sysfs_get_value(d, "vendor");
11f7b31b MM	185	d->device_id = sysfs_get_value(d, "device");
c2b144ef MM	186	d->device_class = sysfs_get_value(d, "class") >> 8;
c2b144ef MM	187	d->known_fields = PCI_FILL_IDENT \| PCI_FILL_CLASS \| PCI_FILL_IRQ \| PCI_FILL_BASES \| PCI_FILL_ROM_BASE \| PCI_FILL_SIZES;
11f7b31b MM	188	}
	189	pci_link_dev(a, d);
	190	}
	191	closedir(dir);
	192	}
	193
2849a165	194	static void
6171c06d	195	sysfs_fill_slots(struct pci_access *a)
2849a165	196	{
2849a165 AC	197	char dirname[1024];
	198	DIR *dir;
	199	struct dirent *entry;
	200	int n;
	201
	202	n = snprintf(dirname, sizeof(dirname), "%s/slots", sysfs_name(a));
	203	if (n < 0 \|\| n >= (int) sizeof(dirname))
	204	a->error("Directory name too long");
	205	dir = opendir(dirname);
	206	if (!dir)
6171c06d MM	207	return;
	208
	209	while (entry = readdir(dir))
2849a165 AC	210	{
	211	char namebuf[OBJNAMELEN], buf[16];
	212	FILE *file;
	213	unsigned int dom, bus, dev;
6171c06d	214	struct pci_dev *d;
2849a165 AC	215
	216	/* ".", ".." or a special non-device perhaps */
	217	if (entry->d_name[0] == '.')
	218	continue;
	219
6171c06d	220	n = snprintf(namebuf, OBJNAMELEN, "%s/%s/%s", dirname, entry->d_name, "address");
2849a165	221	if (n < 0 \|\| n >= OBJNAMELEN)
6171c06d	222	a->error("File name too long");
2849a165	223	file = fopen(namebuf, "r");
534fbba9 MW	224	/*
	225	* Old versions of Linux had a fakephp which didn't have an 'address'
	226	* file. There's no useful information to be gleaned from these
	227	* devices, pretend they're not there.
	228	*/
2849a165	229	if (!file)
534fbba9	230	continue;
6171c06d MM	231
	232	if (!fgets(buf, sizeof(buf), file) \|\| sscanf(buf, "%x:%x:%x", &dom, &bus, &dev) < 3)
	233	a->warning("sysfs_fill_slots: Couldn't parse entry address %s", buf);
	234	else
	235	{
	236	for (d = a->devices; d; d = d->next)
	237	if (dom == d->domain && bus == d->bus && dev == d->dev && !d->phy_slot)
	238	{
	239	d->phy_slot = pci_malloc(a, strlen(entry->d_name) + 1);
	240	strcpy(d->phy_slot, entry->d_name);
6171c06d	241	}
2849a165 AC	242	}
	243	fclose(file);
	244	}
	245	closedir(dir);
	246	}
	247
	248	static int
	249	sysfs_fill_info(struct pci_dev *d, int flags)
	250	{
6171c06d MM	251	if ((flags & PCI_FILL_PHYS_SLOT) && !(d->known_fields & PCI_FILL_PHYS_SLOT))
	252	{
	253	struct pci_dev *pd;
	254	sysfs_fill_slots(d->access);
	255	for (pd = d->access->devices; pd; pd = pd->next)
	256	pd->known_fields \|= PCI_FILL_PHYS_SLOT;
	257	}
	258	return pci_generic_fill_info(d, flags);
2849a165 AC	259	}
2849a165 AC	260
9bd5b1cf BH	261	/* Intent of the sysfs_setup() caller */
	262	enum
	263	{
	264	SETUP_READ_CONFIG = 0,
	265	SETUP_WRITE_CONFIG = 1,
	266	SETUP_READ_VPD = 2
	267	};
	268
11f7b31b	269	static int
9bd5b1cf	270	sysfs_setup(struct pci_dev *d, int intent)
11f7b31b MM	271	{
11f7b31b MM	272	struct pci_access *a = d->access;
9bd5b1cf	273	char namebuf[OBJNAMELEN];
11f7b31b	274
07ad085d	275	if (a->cached_dev != d \|\| (intent == SETUP_WRITE_CONFIG && !a->fd_rw))
11f7b31b	276	{
07ad085d MM	277	sysfs_flush_cache(a);
07ad085d MM	278	a->cached_dev = d;
11f7b31b	279	}
9bd5b1cf	280
07ad085d	281	if (intent == SETUP_READ_VPD)
9bd5b1cf	282	{
07ad085d MM	283	if (a->fd_vpd < 0)
	284	{
	285	sysfs_obj_name(d, "vpd", namebuf);
	286	a->fd_vpd = open(namebuf, O_RDONLY);
	287	/* No warning on error; vpd may be absent or accessible only to root */
	288	}
	289	return a->fd_vpd;
9bd5b1cf BH	290	}
9bd5b1cf BH	291
07ad085d	292	if (a->fd < 0)
c886948c MM	293	{
	294	sysfs_obj_name(d, "config", namebuf);
	295	a->fd_rw = a->writeable \|\| intent == SETUP_WRITE_CONFIG;
	296	a->fd = open(namebuf, a->fd_rw ? O_RDWR : O_RDONLY);
	297	if (a->fd < 0)
	298	a->warning("Cannot open %s", namebuf);
	299	a->fd_pos = 0;
	300	}
07ad085d	301	return a->fd;
11f7b31b MM	302	}
	303
	304	static int sysfs_read(struct pci_dev d, int pos, byte buf, int len)
	305	{
9bd5b1cf	306	int fd = sysfs_setup(d, SETUP_READ_CONFIG);
11f7b31b MM	307	int res;
	308
	309	if (fd < 0)
	310	return 0;
	311	res = do_read(d, fd, buf, len, pos);
	312	if (res < 0)
	313	{
	314	d->access->warning("sysfs_read: read failed: %s", strerror(errno));
	315	return 0;
	316	}
	317	else if (res != len)
09817437	318	return 0;
11f7b31b MM	319	return 1;
	320	}
	321
	322	static int sysfs_write(struct pci_dev d, int pos, byte buf, int len)
	323	{
9bd5b1cf	324	int fd = sysfs_setup(d, SETUP_WRITE_CONFIG);
11f7b31b MM	325	int res;
	326
	327	if (fd < 0)
	328	return 0;
	329	res = do_write(d, fd, buf, len, pos);
	330	if (res < 0)
	331	{
	332	d->access->warning("sysfs_write: write failed: %s", strerror(errno));
	333	return 0;
	334	}
	335	else if (res != len)
	336	{
09817437	337	d->access->warning("sysfs_write: tried to write %d bytes at %d, but only %d succeeded", len, pos, res);
11f7b31b MM	338	return 0;
	339	}
	340	return 1;
	341	}
	342
9bd5b1cf BH	343	#ifdef PCI_HAVE_DO_READ
	344
	345	/* pread() is not available and do_read() only works for a single fd, so we
	346	* cannot implement read_vpd properly. */
	347	static int sysfs_read_vpd(struct pci_dev d, int pos, byte buf, int len)
	348	{
	349	return 0;
	350	}
	351
	352	#else /* !PCI_HAVE_DO_READ */
	353
	354	static int sysfs_read_vpd(struct pci_dev d, int pos, byte buf, int len)
	355	{
	356	int fd = sysfs_setup(d, SETUP_READ_VPD);
	357	int res;
	358
	359	if (fd < 0)
	360	return 0;
	361	res = pread(fd, buf, len, pos);
	362	if (res < 0)
	363	{
	364	d->access->warning("sysfs_read_vpd: read failed: %s", strerror(errno));
	365	return 0;
	366	}
	367	else if (res != len)
	368	return 0;
	369	return 1;
	370	}
	371
	372	#endif /* PCI_HAVE_DO_READ */
	373
11f7b31b MM	374	static void sysfs_cleanup_dev(struct pci_dev *d)
	375	{
	376	struct pci_access *a = d->access;
	377
	378	if (a->cached_dev == d)
07ad085d	379	sysfs_flush_cache(a);
11f7b31b MM	380	}
	381
	382	struct pci_methods pm_linux_sysfs = {
9ff67879 MM	383	"linux-sysfs",
9ff67879 MM	384	"The sys filesystem on Linux",
11f7b31b MM	385	sysfs_config,
	386	sysfs_detect,
	387	sysfs_init,
	388	sysfs_cleanup,
	389	sysfs_scan,
2849a165	390	sysfs_fill_info,
11f7b31b MM	391	sysfs_read,
11f7b31b MM	392	sysfs_write,
9bd5b1cf	393	sysfs_read_vpd,
11f7b31b MM	394	NULL, /* init_dev */
	395	sysfs_cleanup_dev
	396	};