int mtrr_add (unsigned long base, unsigned long size, unsigned int type, char increment);
Memory type region registers control the caching on newer Intel and non Intel processors. This function allows drivers to request an MTRR is added. The details and hardware specifics of each processor's implementation are hidden from the caller, but nevertheless the caller should expect to need to provide a power of two size on an equivalent power of two boundary.
If the region cannot be added either because all regions are in use or the CPU cannot support it a negative value is returned. On success the register number for this entry is returned, but should be treated as a cookie only.
On a multiprocessor machine the changes are made to all processors. This is required on x86 by the Intel processors.
The available types are
MTRR_TYPE_UNCACHABLE - No caching
MTRR_TYPE_WRBACK - Write data back in bursts whenever
MTRR_TYPE_WRCOMB - Write data back soon but allow bursts
MTRR_TYPE_WRTHROUGH - Cache reads but not writes
Needs a quiet flag for the cases where drivers do not mind failures and do not wish system log messages to be sent.
This documentation is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
For more details see the file COPYING in the source distribution of Linux.
If you have comments on the formatting of this manpage, then please contact Michael Still (mikal@stillhq.com).
This documentation was generated with kernel version 2.5.75.