PCICONFIG_READ(2)

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.

SEE ALSO
capabilities(7)