PCICONFIG_READ(2)                   Linux Programmer's Manual                   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 user space.

       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  off‐
              set  (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  appropri‐
              ately.

       pciconfig_write()
              On  success  zero is returned.  On error, -1 is returned and errno is set appropri‐
              ately.

       pciconfig_iobase()
              Returns information on locations of various I/O regions in physical memory  accord‐
              ing 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 pciconfig_iobase().

       EIO    I/O error.

       ENODEV For pciconfig_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  valid  only for pciconfig_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  pcicon‐
              fig_iobase().

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

SEE ALSO
       capabilities(7)

COLOPHON
       This  page  is  part of release 3.74 of the Linux man-pages project.  A description of the
       project, information about reporting bugs, and the latest version of  this  page,  can  be
       found at http://www.kernel.org/doc/man-pages/.



Linux                                       2003-07-14                          PCICONFIG_READ(2)