1<html><head><meta http-equiv="Content-Type" content="text/html; charset=ANSI_X3.4-1968"><title>drm_vma_offset_lock_lookup</title><meta name="generator" content="DocBook XSL Stylesheets V1.78.1"><link rel="home" href="index.html" title="Linux DRM Developer's Guide"><link rel="up" href="drm-memory-management.html#idp1122718668" title="VMA Offset Manager"><link rel="prev" href="API-drm-vma-offset-exact-lookup.html" title="drm_vma_offset_exact_lookup"><link rel="next" href="API-drm-vma-offset-unlock-lookup.html" title="drm_vma_offset_unlock_lookup"></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">drm_vma_offset_lock_lookup</span></th></tr><tr><td width="20%" align="left"><a accesskey="p" href="API-drm-vma-offset-exact-lookup.html">Prev</a>&#160;</td><th width="60%" align="center">VMA Offset Manager</th><td width="20%" align="right">&#160;<a accesskey="n" href="API-drm-vma-offset-unlock-lookup.html">Next</a></td></tr></table><hr></div><div class="refentry"><a name="API-drm-vma-offset-lock-lookup"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>drm_vma_offset_lock_lookup &#8212; 
2     Lock lookup for extended private use
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">void <b class="fsfunc">drm_vma_offset_lock_lookup </b>(</code></td><td>struct drm_vma_offset_manager * <var class="pdparam">mgr</var><code>)</code>;</td></tr></table><div class="funcprototype-spacer">&#160;</div></div></div><div class="refsect1"><a name="idp1122830548"></a><h2>Arguments</h2><div class="variablelist"><dl class="variablelist"><dt><span class="term"><em class="parameter"><code>mgr</code></em></span></dt><dd><p>
4     Manager object
5    </p></dd></dl></div></div><div class="refsect1"><a name="idp1122832076"></a><h2>Description</h2><p>
6   Lock VMA manager for extended lookups. Only *<code class="function">_locked</code> VMA function calls
7   are allowed while holding this lock. All other contexts are blocked from VMA
8   until the lock is released via <code class="function">drm_vma_offset_unlock_lookup</code>.
9   </p><p>
10
11   Use this if you need to take a reference to the objects returned by
12   <code class="function">drm_vma_offset_lookup_locked</code> before releasing this lock again.
13   </p><p>
14
15   This lock must not be used for anything else than extended lookups. You must
16   not call any other VMA helpers while holding this lock.
17</p></div><div class="refsect1"><a name="idp1122834412"></a><h2>Note</h2><p>
18   You're in atomic-context while holding this lock!
19</p></div><div class="refsect1"><a name="idp1122835052"></a><h2>Example</h2><div class="informalexample"><pre class="programlisting">
20     drm_vma_offset_lock_lookup(mgr);
21     node = drm_vma_offset_lookup_locked(mgr);
22     if (node)
23         kref_get_unless_zero(container_of(node, sth, entr));
24     drm_vma_offset_unlock_lookup(mgr);
25</pre></div></div></div><div class="navfooter"><hr><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="API-drm-vma-offset-exact-lookup.html">Prev</a>&#160;</td><td width="20%" align="center"><a accesskey="u" href="drm-memory-management.html#idp1122718668">Up</a></td><td width="40%" align="right">&#160;<a accesskey="n" href="API-drm-vma-offset-unlock-lookup.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top"><span class="phrase">drm_vma_offset_exact_lookup</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">drm_vma_offset_unlock_lookup</span></td></tr></table></div></body></html>
26