1<html><head><meta http-equiv="Content-Type" content="text/html; charset=ANSI_X3.4-1968"><title>arch_phys_wc_add</title><meta name="generator" content="DocBook XSL Stylesheets V1.78.1"><link rel="home" href="index.html" title="The Linux Kernel API"><link rel="up" href="ch09s04.html" title="MTRR Handling"><link rel="prev" href="API-mtrr-del.html" title="mtrr_del"><link rel="next" href="ch09s05.html" title="PCI Support Library"></head><body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center"><span class="phrase">arch_phys_wc_add</span></th></tr><tr><td width="20%" align="left"><a accesskey="p" href="API-mtrr-del.html">Prev</a>&#160;</td><th width="60%" align="center">MTRR Handling</th><td width="20%" align="right">&#160;<a accesskey="n" href="ch09s05.html">Next</a></td></tr></table><hr></div><div class="refentry"><a name="API-arch-phys-wc-add"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>arch_phys_wc_add &#8212; 
2     add a WC MTRR and handle errors if PAT is unavailable
3 </p></div><div class="refsynopsisdiv"><h2>Synopsis</h2><div class="funcsynopsis"><table border="0" class="funcprototype-table" summary="Function synopsis" style="cellspacing: 0; cellpadding: 0;"><tr><td><code class="funcdef">int <b class="fsfunc">arch_phys_wc_add </b>(</code></td><td>unsigned long <var class="pdparam">base</var>, </td></tr><tr><td>&#160;</td><td>unsigned long <var class="pdparam">size</var><code>)</code>;</td></tr></table><div class="funcprototype-spacer">&#160;</div></div></div><div class="refsect1"><a name="idp1126052580"></a><h2>Arguments</h2><div class="variablelist"><dl class="variablelist"><dt><span class="term"><em class="parameter"><code>base</code></em></span></dt><dd><p>
4     Physical base address
5    </p></dd><dt><span class="term"><em class="parameter"><code>size</code></em></span></dt><dd><p>
6     Size of region
7    </p></dd></dl></div></div><div class="refsect1"><a name="idp1126055212"></a><h2>Description</h2><p>
8   If PAT is available, this does nothing.  If PAT is unavailable, it
9   attempts to add a WC MTRR covering size bytes starting at base and
10   logs an error if this fails.
11   </p><p>
12
13   Drivers must store the return value to pass to mtrr_del_wc_if_needed,
14   but drivers should not try to interpret that return value.
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