PCICONFIG_READ(2) Linux Programmer's Manual PCICONFIG_READ(2)NAME
pciconfig_read, pciconfig_write, pciconfig_iobase - pci device informa‐
tion 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 ker‐
nel 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 VALUEpciconfig_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 phys‐
ical 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 ALSOcapabilities(7)Linux 2.4.19 2003-07-14 PCICONFIG_READ(2)
