flush the translation lookaside buffer
is used to flush the Translation Lookahead Buffer (TLA)
for older hardware.
function is supplied for users of very early
versions of 16 and 25 MHz 386 systems
using Micro Channel cards,
where, when accessing an I/O port above 0x1000,
a driver must flush the translate lookaside buffer
A call to
prevents corruption of the I/O address.
Note that the call to
must be protected
by a call to
to prevent interrupts from occurring while flushtlb is
Context and synchronization
Very early versions of 16 and 25 MHz 386 systems
using Micro Channel cards.
Differences between versions
This function is not required for any current hardware.
Current drivers can just delete calls to this function.
SVR5 DDI compatibility
This function is not supported for DDI drivers.
It is not required for current hardware
and so can just be deleted when porting drivers to DDI.
The following example is for a driver routine that gets a byte from
an I/O port and checks the address before beginning
processing. A driver should also have a similar routine for writing
data to an I/O port.
int x, ret;
* If port address is less than hex 1000,
* get byte and return.
if (port < 0x1000)
/* else, */
x = spl7(); /* block all interrupts */
flushtlb(); /* flush TLB */
ret = inb(port); /* get byte from port */
splx(x); /* reset previous spl */
return(ret); /* return byte to caller */
19 June 2005
© 2005 The SCO Group, Inc. All rights reserved.
OpenServer 5 HDK - June 2005