cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
Log | Files | Refs | README | LICENSE | sfeed.txt

copy.c (2883B)

      1/*
      2 *  Linear conversion Plug-In
      3 *  Copyright (c) 2000 by Abramo Bagnara <abramo@alsa-project.org>
      4 *
      5 *
      6 *   This library is free software; you can redistribute it and/or modify
      7 *   it under the terms of the GNU Library General Public License as
      8 *   published by the Free Software Foundation; either version 2 of
      9 *   the License, or (at your option) any later version.
     10 *
     11 *   This program is distributed in the hope that it will be useful,
     12 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
     13 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
     14 *   GNU Library General Public License for more details.
     15 *
     16 *   You should have received a copy of the GNU Library General Public
     17 *   License along with this library; if not, write to the Free Software
     18 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
     19 *
     20 */
     21
     22#include <linux/time.h>
     23#include <sound/core.h>
     24#include <sound/pcm.h>
     25#include "pcm_plugin.h"
     26
     27static snd_pcm_sframes_t copy_transfer(struct snd_pcm_plugin *plugin,
     28			     const struct snd_pcm_plugin_channel *src_channels,
     29			     struct snd_pcm_plugin_channel *dst_channels,
     30			     snd_pcm_uframes_t frames)
     31{
     32	unsigned int channel;
     33	unsigned int nchannels;
     34
     35	if (snd_BUG_ON(!plugin || !src_channels || !dst_channels))
     36		return -ENXIO;
     37	if (frames == 0)
     38		return 0;
     39	nchannels = plugin->src_format.channels;
     40	for (channel = 0; channel < nchannels; channel++) {
     41		if (snd_BUG_ON(src_channels->area.first % 8 ||
     42			       src_channels->area.step % 8))
     43			return -ENXIO;
     44		if (snd_BUG_ON(dst_channels->area.first % 8 ||
     45			       dst_channels->area.step % 8))
     46			return -ENXIO;
     47		if (!src_channels->enabled) {
     48			if (dst_channels->wanted)
     49				snd_pcm_area_silence(&dst_channels->area, 0, frames, plugin->dst_format.format);
     50			dst_channels->enabled = 0;
     51			continue;
     52		}
     53		dst_channels->enabled = 1;
     54		snd_pcm_area_copy(&src_channels->area, 0, &dst_channels->area, 0, frames, plugin->src_format.format);
     55		src_channels++;
     56		dst_channels++;
     57	}
     58	return frames;
     59}
     60
     61int snd_pcm_plugin_build_copy(struct snd_pcm_substream *plug,
     62			      struct snd_pcm_plugin_format *src_format,
     63			      struct snd_pcm_plugin_format *dst_format,
     64			      struct snd_pcm_plugin **r_plugin)
     65{
     66	int err;
     67	struct snd_pcm_plugin *plugin;
     68	int width;
     69
     70	if (snd_BUG_ON(!r_plugin))
     71		return -ENXIO;
     72	*r_plugin = NULL;
     73
     74	if (snd_BUG_ON(src_format->format != dst_format->format))
     75		return -ENXIO;
     76	if (snd_BUG_ON(src_format->rate != dst_format->rate))
     77		return -ENXIO;
     78	if (snd_BUG_ON(src_format->channels != dst_format->channels))
     79		return -ENXIO;
     80
     81	width = snd_pcm_format_physical_width(src_format->format);
     82	if (snd_BUG_ON(width <= 0))
     83		return -ENXIO;
     84
     85	err = snd_pcm_plugin_build(plug, "copy", src_format, dst_format,
     86				   0, &plugin);
     87	if (err < 0)
     88		return err;
     89	plugin->transfer = copy_transfer;
     90	*r_plugin = plugin;
     91	return 0;
     92}