Skip site navigation (1)Skip section navigation (2)

FreeBSD Man Pages

Man Page or Keyword Search:
Man Architecture
Apropos Keyword Search (all sections) Output format
home | help
PCI(4)		       FreeBSD Kernel Interfaces Manual			PCI(4)

NAME
     pci -- generic PCI	driver

SYNOPSIS
     device pci

DESCRIPTION
     The pci driver provides a way for userland	programs to read and write PCI
     configuration registers.  It also provides	a way for userland programs to
     get a list	of all PCI devices, or all PCI devices that match various pat-
     terns.

     Since the pci driver provides a write interface for PCI configuration
     registers,	system administrators should exercise caution when granting
     access to the pci device.	If used	improperly, this driver	can allow
     userland applications to crash a machine or cause data loss.

KERNEL CONFIGURATION
     It	is only	necessary to specify one pci controller	in the kernel.	Addi-
     tional PCI	busses are handled automatically as they are encountered.

IOCTLS
     The following ioctl(2) calls are supported	by the pci driver.  They are
     defined in	the header file	<sys/pciio.h>.

     PCIOCGETCONF     This ioctl(2) takes a pci_conf_io	structure.  It allows
		      the user to retrieve information on all PCI devices in
		      the system, or on	PCI devices matching patterns supplied
		      by the user.  The	pci_conf_io structure consists of a
		      number of	fields:

		      pat_buf_len    The length, in bytes, of the buffer
				     filled with user-supplied patterns.

		      num_patterns   The number	of user-supplied patterns.

		      patterns	     Pointer to	a buffer filled	with user-sup-
				     plied patterns.  patterns is a pointer to
				     num_patterns pci_match_conf structures.
				     The pci_match_conf	structure consists of
				     the following elements:

				     pc_sel	PCI bus, slot and function.

				     pd_name	PCI device driver name.

				     pd_unit	PCI device driver unit number.

				     pc_vendor	PCI vendor ID.

				     pc_device	PCI device ID.

				     pc_class	PCI device class.

				     flags	The flags describe which of
						the fields the kernel should
						match against.	A device must
						match all specified fields in
						order to be returned.  The
						match flags are	enumerated in
						the pci_getconf_flags struc-
						ture.  Hopefully the flag val-
						ues are	obvious	enough that
						they don't need	to described
						in detail.

		      match_buf_len  Length of the matches buffer allocated by
				     the user to hold the results of the
				     PCIOCGETCONF query.

		      num_matches    Number of matches returned	by the kernel.

		      matches	     Buffer containing matching	devices
				     returned by the kernel.  The items	in
				     this buffer are of	type pci_conf, which
				     consists of the following items:

				     pc_sel	   PCI bus, slot and function.

				     pc_hdr	   PCI header type.

				     pc_subvendor  PCI subvendor ID.

				     pc_subdevice  PCI subdevice ID.

				     pc_vendor	   PCI vendor ID.

				     pc_device	   PCI device ID.

				     pc_class	   PCI device class.

				     pc_subclass   PCI device subclass.

				     pc_progif	   PCI device programming
						   interface.

				     pc_revid	   PCI revision	ID.

				     pd_name	   Driver name.

				     pd_unit	   Driver unit number.

		      offset	     The offset	is passed in by	the user to
				     tell the kernel where it should start
				     traversing	the device list.  The value
				     passed out	by the kernel points to	the
				     record immediately	after the last one
				     returned.	The user may pass the value
				     returned by the kernel in subsequent
				     calls to the PCIOCGETCONF ioctl.  If the
				     user does not intend to use the offset,
				     it	must be	set to zero.

		      generation     PCI configuration generation.  This value
				     only needs	to be set if the offset	is
				     set.  The kernel will compare the current
				     generation	number of its internal device
				     list to the generation passed in by the
				     user to determine whether its device list
				     has changed since the user	last called
				     the PCIOCGETCONF ioctl.  If the device
				     list has changed, a status	of
				     PCI_GETCONF_LIST_CHANGED will be passed
				     back.

		      status	     The status	tells the user the disposition
				     of	his request for	a device list.	The
				     possible status values are:

				     PCI_GETCONF_LAST_DEVICE
				     This means	that there are no more devices
				     in	the PCI	device list after the ones
				     returned in the matches buffer.

				     PCI_GETCONF_LIST_CHANGED
				     This status tells the user	that the PCI
				     device list has changed since his last
				     call to the PCIOCGETCONF ioctl and	he
				     must reset	the offset and generation to
				     zero to start over	at the beginning of
				     the list.

				     PCI_GETCONF_MORE_DEVS
				     This tells	the user that his buffer was
				     not large enough to hold all of the
				     remaining devices in the device list that
				     possibly match his	criteria.  It is pos-
				     sible for this status to be returned,
				     even when none of the remaining devices
				     in	the list would match the user's	crite-
				     ria.

				     PCI_GETCONF_ERROR
				     This indicates a general error while ser-
				     vicing the	user's request.	 A more	spe-
				     cific indication of the problem may or
				     may not be	printed	in the kernel message
				     buffer (and by implication, the system
				     console).

     PCIOCREAD	      This ioctl(2) reads the PCI configuration	registers
		      specified	by the passed-in pci_io	structure.  The	pci_io
		      structure	consists of the	following fields:

		      pi_sel	A pcisel structure which specifies the bus,
				slot and function the user would like to
				query.

		      pi_reg	The PCI	configuration register the user	would
				like to	access.

		      pi_width	The width, in bytes, of	the data the user
				would like to read.  This value	may be either
				1, 2, or 4.  3-byte reads and reads larger
				than 4 bytes are not supported.

		      pi_data	The data returned by the kernel.

     PCIOCWRITE	      This ioctl(2) allows users to write to the PCI specified
		      in the passed-in pci_io structure.  The pci_io structure
		      is described above.  The limitations on data width
		      described	for reading registers, above, also apply to
		      writing PCI configuration	registers.

FILES
     /dev/pci  Character device	for the	pci driver.

DIAGNOSTICS
     None.

SEE ALSO
     pciconf(8)

HISTORY
     The pci driver (not the kernel's PCI support code)	first appeared in
     FreeBSD 2.2, and was written by Stefan Esser and Garrett Wollman.	Sup-
     port for device listing and matching was re-implemented by	Kenneth	Merry,
     and first appeared	in FreeBSD 3.0.

AUTHORS
     Kenneth Merry <ken@FreeBSD.org>

BUGS
     It	isn't possible for users to specify an accurate	offset into the	device
     list without calling the PCIOCGETCONF at least once, since	they have no
     way of knowing the	current	generation number otherwise.  This probably
     isn't a serious problem, though, since users can easily narrow their
     search by specifying a pattern or patterns	for the	kernel to match
     against.

FreeBSD	10.1		       October 24, 1999			  FreeBSD 10.1

NAME | SYNOPSIS | DESCRIPTION | KERNEL CONFIGURATION | IOCTLS | FILES | DIAGNOSTICS | SEE ALSO | HISTORY | AUTHORS | BUGS

Want to link to this manual page? Use this URL:
<http://www.freebsd.org/cgi/man.cgi?query=pci&sektion=4&manpath=FreeBSD+4.11-RELEASE>

home | help