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,
                          unsigned char *buf);
       int pciconfig_write(unsigned long bus, unsigned long dfn,
                          unsigned long off, unsigned long len,
                          unsigned char *buf);
       int pciconfig_iobase(int 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
              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  to
              indicate the error.

       pciconfig_write()
              On  success,  zero  is  returned.   On  error,  -1  is returned and errno is set to
              indicate the error.

       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

       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
              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 5.13 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/.