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Manual Reference Pages  - PCICONFIG_READ (2)

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pciconfig_read, pciconfig_write, pciconfig_iobase - pci device information handling

CONTENTS

Synopsis
Description
Errors

#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); 

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.

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.

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.

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

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