1<html><head><meta http-equiv="Content-Type" content="text/html; charset=ANSI_X3.4-1968"><title>dma_mmap_from_coherent</title><meta name="generator" content="DocBook XSL Stylesheets V1.78.1"><link rel="home" href="index.html" title="Linux Device Drivers"><link rel="up" href="ch02s03.html" title="Device Drivers DMA Management"><link rel="prev" href="API-dma-release-from-coherent.html" title="dma_release_from_coherent"><link rel="next" href="API-dmam-alloc-coherent.html" title="dmam_alloc_coherent"></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">dma_mmap_from_coherent</span></th></tr><tr><td width="20%" align="left"><a accesskey="p" href="API-dma-release-from-coherent.html">Prev</a>&#160;</td><th width="60%" align="center">Device Drivers DMA Management</th><td width="20%" align="right">&#160;<a accesskey="n" href="API-dmam-alloc-coherent.html">Next</a></td></tr></table><hr></div><div class="refentry"><a name="API-dma-mmap-from-coherent"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>dma_mmap_from_coherent &#8212; 
2     try to mmap the memory allocated from per-device coherent memory pool to userspace
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">dma_mmap_from_coherent </b>(</code></td><td>struct device * <var class="pdparam">dev</var>, </td></tr><tr><td>&#160;</td><td>struct vm_area_struct * <var class="pdparam">vma</var>, </td></tr><tr><td>&#160;</td><td>void * <var class="pdparam">vaddr</var>, </td></tr><tr><td>&#160;</td><td>size_t <var class="pdparam">size</var>, </td></tr><tr><td>&#160;</td><td>int * <var class="pdparam">ret</var><code>)</code>;</td></tr></table><div class="funcprototype-spacer">&#160;</div></div></div><div class="refsect1"><a name="idp1110534716"></a><h2>Arguments</h2><div class="variablelist"><dl class="variablelist"><dt><span class="term"><em class="parameter"><code>dev</code></em></span></dt><dd><p>
4     device from which the memory was allocated
5    </p></dd><dt><span class="term"><em class="parameter"><code>vma</code></em></span></dt><dd><p>
6     vm_area for the userspace memory
7    </p></dd><dt><span class="term"><em class="parameter"><code>vaddr</code></em></span></dt><dd><p>
8     cpu address returned by dma_alloc_from_coherent
9    </p></dd><dt><span class="term"><em class="parameter"><code>size</code></em></span></dt><dd><p>
10     size of the memory buffer allocated by dma_alloc_from_coherent
11    </p></dd><dt><span class="term"><em class="parameter"><code>ret</code></em></span></dt><dd><p>
12     result from <code class="function">remap_pfn_range</code>
13    </p></dd></dl></div></div><div class="refsect1"><a name="idp1110540812"></a><h2>Description</h2><p>
14   This checks whether the memory was allocated from the per-device
15   coherent memory pool and if so, maps that memory to the provided vma.
16   </p><p>
17
18   Returns 1 if we correctly mapped the memory, or 0 if the caller should
19   proceed with mapping memory from generic pools.
20</p></div></div><div class="navfooter"><hr><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="API-dma-release-from-coherent.html">Prev</a>&#160;</td><td width="20%" align="center"><a accesskey="u" href="ch02s03.html">Up</a></td><td width="40%" align="right">&#160;<a accesskey="n" href="API-dmam-alloc-coherent.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top"><span class="phrase">dma_release_from_coherent</span>&#160;</td><td width="20%" align="center"><a accesskey="h" href="index.html">Home</a></td><td width="40%" align="right" valign="top">&#160;<span class="phrase">dmam_alloc_coherent</span></td></tr></table></div></body></html>
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