pciconfig_read(2) -- Linux man page

 

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

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

CONFORMING TO

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