xref: /OK3568_Linux_fs/kernel/Documentation/userspace-api/media/dvb/dmx-munmap.rst (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593Smuzhiyun.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later
2*4882a593Smuzhiyun.. c:namespace:: DTV.dmx
3*4882a593Smuzhiyun
4*4882a593Smuzhiyun.. _dmx-munmap:
5*4882a593Smuzhiyun
6*4882a593Smuzhiyun************
7*4882a593SmuzhiyunDVB munmap()
8*4882a593Smuzhiyun************
9*4882a593Smuzhiyun
10*4882a593SmuzhiyunName
11*4882a593Smuzhiyun====
12*4882a593Smuzhiyun
13*4882a593Smuzhiyundmx-munmap - Unmap device memory
14*4882a593Smuzhiyun
15*4882a593Smuzhiyun.. warning:: This API is still experimental.
16*4882a593Smuzhiyun
17*4882a593SmuzhiyunSynopsis
18*4882a593Smuzhiyun========
19*4882a593Smuzhiyun
20*4882a593Smuzhiyun.. code-block:: c
21*4882a593Smuzhiyun
22*4882a593Smuzhiyun    #include <unistd.h>
23*4882a593Smuzhiyun    #include <sys/mman.h>
24*4882a593Smuzhiyun
25*4882a593Smuzhiyun.. c:function:: int munmap( void *start, size_t length )
26*4882a593Smuzhiyun
27*4882a593SmuzhiyunArguments
28*4882a593Smuzhiyun=========
29*4882a593Smuzhiyun
30*4882a593Smuzhiyun``start``
31*4882a593Smuzhiyun    Address of the mapped buffer as returned by the
32*4882a593Smuzhiyun    :c:func:`mmap()` function.
33*4882a593Smuzhiyun
34*4882a593Smuzhiyun``length``
35*4882a593Smuzhiyun    Length of the mapped buffer. This must be the same value as given to
36*4882a593Smuzhiyun    :c:func:`mmap()`.
37*4882a593Smuzhiyun
38*4882a593SmuzhiyunDescription
39*4882a593Smuzhiyun===========
40*4882a593Smuzhiyun
41*4882a593SmuzhiyunUnmaps a previously with the :c:func:`mmap()` function mapped
42*4882a593Smuzhiyunbuffer and frees it, if possible.
43*4882a593Smuzhiyun
44*4882a593SmuzhiyunReturn Value
45*4882a593Smuzhiyun============
46*4882a593Smuzhiyun
47*4882a593SmuzhiyunOn success :c:func:`munmap()` returns 0, on failure -1 and the
48*4882a593Smuzhiyun``errno`` variable is set appropriately:
49*4882a593Smuzhiyun
50*4882a593SmuzhiyunEINVAL
51*4882a593Smuzhiyun    The ``start`` or ``length`` is incorrect, or no buffers have been
52*4882a593Smuzhiyun    mapped yet.
53