'\" t .\" Title: arch_phys_wc_add .\" Author: [FIXME: author] [see http://docbook.sf.net/el/author] .\" Generator: DocBook XSL Stylesheets v1.79.1 .\" Date: July 2017 .\" Manual: Hardware Interfaces .\" Source: Kernel Hackers Manual 4.11.6 .\" Language: English .\" .TH "ARCH_PHYS_WC_ADD" "9" "July 2017" "Kernel Hackers Manual 4\&.11\&" "Hardware Interfaces" .\" ----------------------------------------------------------------- .\" * Define some portability stuff .\" ----------------------------------------------------------------- .\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .\" http://bugs.debian.org/507673 .\" http://lists.gnu.org/archive/html/groff/2009-02/msg00013.html .\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .ie \n(.g .ds Aq \(aq .el .ds Aq ' .\" ----------------------------------------------------------------- .\" * set default formatting .\" ----------------------------------------------------------------- .\" disable hyphenation .nh .\" disable justification (adjust text to left margin only) .ad l .\" ----------------------------------------------------------------- .\" * MAIN CONTENT STARTS HERE * .\" ----------------------------------------------------------------- .SH "NAME" arch_phys_wc_add \- add a WC MTRR and handle errors if PAT is unavailable .SH "SYNOPSIS" .HP \w'int\ arch_phys_wc_add('u .BI "int arch_phys_wc_add(unsigned\ long\ " "base" ", unsigned\ long\ " "size" ");" .SH "ARGUMENTS" .PP \fIunsigned long base\fR .RS 4 Physical base address .RE .PP \fIunsigned long size\fR .RS 4 Size of region .RE .SH "DESCRIPTION" .PP If PAT is available, this does nothing\&. If PAT is unavailable, it attempts to add a WC MTRR covering size bytes starting at base and logs an error if this fails\&. .PP The called should provide a power of two size on an equivalent power of two boundary\&. .PP Drivers must store the return value to pass to mtrr_del_wc_if_needed, but drivers should not try to interpret that return value\&. .SH "COPYRIGHT" .br