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 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  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 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   pcicon-
              fig_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 pciconfig_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 4.16 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
       https://www.kernel.org/doc/man-pages/.



Linux                             2016-07-17                 PCICONFIG_READ(2)