<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN"> <HTML ><HEAD ><TITLE >ioremap_nocache</TITLE ><META NAME="GENERATOR" CONTENT="Modular DocBook HTML Stylesheet Version 1.7"><LINK REL="HOME" TITLE="Bus-Independent Device Accesses" HREF="book1.html"><LINK REL="UP" TITLE="Public Functions Provided" HREF="c96.html"><LINK REL="PREVIOUS" TITLE="ioremap" HREF="r152.html"><LINK REL="NEXT" TITLE="check_signature" HREF="r220.html"></HEAD ><BODY CLASS="REFENTRY" BGCOLOR="#FFFFFF" TEXT="#000000" LINK="#0000FF" VLINK="#840084" ALINK="#0000FF" ><DIV CLASS="NAVHEADER" ><TABLE SUMMARY="Header navigation table" WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TH COLSPAN="3" ALIGN="center" >Bus-Independent Device Accesses</TH ></TR ><TR ><TD WIDTH="10%" ALIGN="left" VALIGN="bottom" ><A HREF="r152.html" ACCESSKEY="P" ><<< Previous</A ></TD ><TD WIDTH="80%" ALIGN="center" VALIGN="bottom" ></TD ><TD WIDTH="10%" ALIGN="right" VALIGN="bottom" ><A HREF="r220.html" ACCESSKEY="N" >Next >>></A ></TD ></TR ></TABLE ><HR ALIGN="LEFT" WIDTH="100%"></DIV ><H1 ><A NAME="AEN185" ></A ><SPAN CLASS="phrase" ><SPAN CLASS="PHRASE" >ioremap_nocache</SPAN ></SPAN ></H1 ><DIV CLASS="REFNAMEDIV" ><A NAME="AEN189" ></A ><H2 >Name</H2 >ioremap_nocache -- map bus memory into CPU space </DIV ><DIV CLASS="REFSYNOPSISDIV" ><A NAME="AEN192" ></A ><H2 >Synopsis</H2 ><DIV CLASS="FUNCSYNOPSIS" ><A NAME="AEN194" ></A ><P ></P ><P ><CODE ><CODE CLASS="FUNCDEF" >void * <TT CLASS="FUNCTION" >ioremap_nocache </TT ></CODE >(unsigned long <TT CLASS="PARAMETER" ><I >offset</I ></TT >, unsigned long <TT CLASS="PARAMETER" ><I >size</I ></TT >);</CODE ></P ><P ></P ></DIV ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN202" ></A ><H2 >Arguments</H2 ><P ></P ><DIV CLASS="VARIABLELIST" ><DL ><DT ><TT CLASS="PARAMETER" ><I >offset</I ></TT ></DT ><DD ><P > bus address of the memory </P ></DD ><DT ><TT CLASS="PARAMETER" ><I >size</I ></TT ></DT ><DD ><P > size of the resource to map </P ></DD ></DL ></DIV ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN215" ></A ><H2 >Description</H2 ><P > ioremap_nocache performs a platform specific sequence of operations to make bus memory CPU accessible via the readb/readw/readl/writeb/ writew/writel functions and the other mmio helpers. The returned address is not guaranteed to be usable directly as a virtual address. </P ><P > This version of ioremap ensures that the memory is marked uncachable on the CPU as well as honouring existing caching rules from things like the PCI bus. Note that there are other caches and buffers on many busses. In paticular driver authors should read up on PCI writes </P ><P > It's useful if some control registers are in such an area and </P ></DIV ><DIV CLASS="NAVFOOTER" ><HR ALIGN="LEFT" WIDTH="100%"><TABLE SUMMARY="Footer navigation table" WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" ><A HREF="r152.html" ACCESSKEY="P" ><<< Previous</A ></TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="book1.html" ACCESSKEY="H" >Home</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" ><A HREF="r220.html" ACCESSKEY="N" >Next >>></A ></TD ></TR ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" ><SPAN CLASS="phrase" ><SPAN CLASS="PHRASE" >ioremap</SPAN ></SPAN ></TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="c96.html" ACCESSKEY="U" >Up</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" ><SPAN CLASS="phrase" ><SPAN CLASS="PHRASE" >check_signature</SPAN ></SPAN ></TD ></TR ></TABLE ></DIV ></BODY ></HTML >