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

io.c (4429B)

      1/*
      2 *  PCM I/O Plug-In Interface
      3 *  Copyright (c) 1999 by Jaroslav Kysela <perex@perex.cz>
      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 <sound/pcm_params.h>
     26#include "pcm_plugin.h"
     27
     28#define pcm_write(plug,buf,count) snd_pcm_oss_write3(plug,buf,count,1)
     29#define pcm_writev(plug,vec,count) snd_pcm_oss_writev3(plug,vec,count)
     30#define pcm_read(plug,buf,count) snd_pcm_oss_read3(plug,buf,count,1)
     31#define pcm_readv(plug,vec,count) snd_pcm_oss_readv3(plug,vec,count)
     32
     33/*
     34 *  Basic io plugin
     35 */
     36 
     37static snd_pcm_sframes_t io_playback_transfer(struct snd_pcm_plugin *plugin,
     38				    const struct snd_pcm_plugin_channel *src_channels,
     39				    struct snd_pcm_plugin_channel *dst_channels,
     40				    snd_pcm_uframes_t frames)
     41{
     42	if (snd_BUG_ON(!plugin))
     43		return -ENXIO;
     44	if (snd_BUG_ON(!src_channels))
     45		return -ENXIO;
     46	if (plugin->access == SNDRV_PCM_ACCESS_RW_INTERLEAVED) {
     47		return pcm_write(plugin->plug, src_channels->area.addr, frames);
     48	} else {
     49		int channel, channels = plugin->dst_format.channels;
     50		void **bufs = (void**)plugin->extra_data;
     51		if (snd_BUG_ON(!bufs))
     52			return -ENXIO;
     53		for (channel = 0; channel < channels; channel++) {
     54			if (src_channels[channel].enabled)
     55				bufs[channel] = src_channels[channel].area.addr;
     56			else
     57				bufs[channel] = NULL;
     58		}
     59		return pcm_writev(plugin->plug, bufs, frames);
     60	}
     61}
     62 
     63static snd_pcm_sframes_t io_capture_transfer(struct snd_pcm_plugin *plugin,
     64				   const struct snd_pcm_plugin_channel *src_channels,
     65				   struct snd_pcm_plugin_channel *dst_channels,
     66				   snd_pcm_uframes_t frames)
     67{
     68	if (snd_BUG_ON(!plugin))
     69		return -ENXIO;
     70	if (snd_BUG_ON(!dst_channels))
     71		return -ENXIO;
     72	if (plugin->access == SNDRV_PCM_ACCESS_RW_INTERLEAVED) {
     73		return pcm_read(plugin->plug, dst_channels->area.addr, frames);
     74	} else {
     75		int channel, channels = plugin->dst_format.channels;
     76		void **bufs = (void**)plugin->extra_data;
     77		if (snd_BUG_ON(!bufs))
     78			return -ENXIO;
     79		for (channel = 0; channel < channels; channel++) {
     80			if (dst_channels[channel].enabled)
     81				bufs[channel] = dst_channels[channel].area.addr;
     82			else
     83				bufs[channel] = NULL;
     84		}
     85		return pcm_readv(plugin->plug, bufs, frames);
     86	}
     87	return 0;
     88}
     89 
     90static snd_pcm_sframes_t io_src_channels(struct snd_pcm_plugin *plugin,
     91			     snd_pcm_uframes_t frames,
     92			     struct snd_pcm_plugin_channel **channels)
     93{
     94	int err;
     95	unsigned int channel;
     96	struct snd_pcm_plugin_channel *v;
     97	err = snd_pcm_plugin_client_channels(plugin, frames, &v);
     98	if (err < 0)
     99		return err;
    100	*channels = v;
    101	if (plugin->access == SNDRV_PCM_ACCESS_RW_INTERLEAVED) {
    102		for (channel = 0; channel < plugin->src_format.channels; ++channel, ++v)
    103			v->wanted = 1;
    104	}
    105	return frames;
    106}
    107
    108int snd_pcm_plugin_build_io(struct snd_pcm_substream *plug,
    109			    struct snd_pcm_hw_params *params,
    110			    struct snd_pcm_plugin **r_plugin)
    111{
    112	int err;
    113	struct snd_pcm_plugin_format format;
    114	struct snd_pcm_plugin *plugin;
    115
    116	if (snd_BUG_ON(!r_plugin))
    117		return -ENXIO;
    118	*r_plugin = NULL;
    119	if (snd_BUG_ON(!plug || !params))
    120		return -ENXIO;
    121	format.format = params_format(params);
    122	format.rate = params_rate(params);
    123	format.channels = params_channels(params);
    124	err = snd_pcm_plugin_build(plug, "I/O io",
    125				   &format, &format,
    126				   sizeof(void *) * format.channels,
    127				   &plugin);
    128	if (err < 0)
    129		return err;
    130	plugin->access = params_access(params);
    131	if (snd_pcm_plug_stream(plug) == SNDRV_PCM_STREAM_PLAYBACK) {
    132		plugin->transfer = io_playback_transfer;
    133		if (plugin->access == SNDRV_PCM_ACCESS_RW_INTERLEAVED)
    134			plugin->client_channels = io_src_channels;
    135	} else {
    136		plugin->transfer = io_capture_transfer;
    137	}
    138
    139	*r_plugin = plugin;
    140	return 0;
    141}