PCICONFIG_READ

Section: Linux Programmer's Manual (2)
Updated: 2003-07-14
Index Return to Main Contents

NAME

pciconfig_read, pciconfig_write, pciconfig_iobase - pci device information handling

SYNOPSIS

#include <pci.h>

int pciconfig_read(unsigned long bus, unsigned long dfn,
     unsigned long off, unsigned long len, void *buf);
int pciconfig_write(unsigned long bus, unsigned long dfn,
     unsigned long off, unsigned long len, void *buf);
int pciconfig_iobase(long which, unsigned long bus,
     unsigned long devfn);

DESCRIPTION

Most of the interaction with PCI devices is already handled by the kernel PCI layer, and thus these calls should not normally need to be accessed from userspace.
pciconfig_read: Reads to buf from device dev at offset off value.
pciconfig_write: Writes from buf to device dev at offset off value.
pciconfig_iobase: You pass it a bus/devfn pair and get a physical address for either the memory offset (for things like prep, this is 0xc0000000), the IO base for PIO cycles, or the ISA holes if any.

RETURN VALUE

pciconfig_read: On success zero is returned. On error, -1 is returned and errno is set appropriately.
pciconfig_write: On success zero is returned. On error, -1 is returned and errno is set appropriately.
pciconfig_iobase: Returns information on locations of various I/O regions in physical memory according to the which value. Values for which are: IOBASE_BRIDGE_NUMBER, IOBASE_MEMORY, IOBASE_IO, IOBASE_ISA_IO, IOBASE_ISA_MEM.

ERRORS

EINVAL: len value is invalid. This does not apply to pci_iobase.
EIO: I/O error.
ENODEV: For pci_iobase, hose value is NULL? For the other calls, could not find a slot.
ENOSYS: The system has not implemented these calls (CONFIG_PCI not defined).
EOPNOTSUPP: This return value is only valid for pci_iobase. It is returned if the value for which is invalid.
EPERM: User does not have the CAP_SYS_ADMIN capability. This does not apply to pci_iobase.

CONFORMING TO

These calls are Linux specific, available since Linux 2.0.26/2.1.11.

This document was created by man2html, using the manual pages.
Time: 00:11:36 GMT, May 13, 2005