wbadaddr(D3X)

NAME
     wbadaddr - test for valid output bus address
     wbadaddr_val - test for valid output bus address and write value

SYNOPSIS
     #include <sys/systm.h>
     int wbadaddr(volatile void *addr, int size);
     int wbadaddr_val(volatile void *addr, int size, void *ptr);

   Arguments
     addr The physical memory address of the location to be tested.

     size The size in bytes of the location to be written: 1, 2, 4, or 8.

     ptr  A pointer to a value of the appropriate size (char, short, int, or
          long long) whose value is written to the given location.

DESCRIPTION
     Typically these functions are called from a VME device driver's init(D2)
     or edtinit(D2) function to determine whether a device is present in the
     system.

     Call wbadaddr to determine whether you can write to location addr.  It
     writes a binary zero of the specified size.

     Call wbadaddr_val when you also want to specify the data to be written.

     Use badaddr(D3X) to test a location for input only.

NOTES
     If an invalid size is passed a system panic results.

     For some systems, pio_wbadaddr(D3X) must be used in order to perform
     address mapping.

     It is possible that the wbadaddr_val(D3X) function may change or be
     removed in the future.

     These routines may not be called from an interrupt handler, or routines
     that may be called from an interrupt handler.

   Return Values
     Both functions return 0 when addr is writeable.  Otherwise, they return
     1.

   See Also
     badaddr(D3X), edtinit(D2), pio_wbadaddr(D3X).