pciconfig_read(2)             System Calls Manual            pciconfig_read(2)

NAME
       pciconfig_read, pciconfig_write, pciconfig_iobase - pci device
       information handling

LIBRARY
       Standard C library (libc, -lc)

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().

STANDARDS
       Linux.

HISTORY
       Linux 2.0.26/2.1.11.

SEE ALSO
       capabilities(7)

Linux man-pages 6.7               2023-10-31                 pciconfig_read(2)