/*
 * edma-pcm.c - eDMA PCM driver using dmaengine for AM3xxx, AM4xxx
 *
 * Copyright (C) 2014 Texas Instruments, Inc.
 *
 * Author: Peter Ujfalusi <peter.ujfalusi@ti.com>
 *
 * Based on: sound/soc/tegra/tegra_pcm.c
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * version 2 as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 */

#include <linux/module.h>
#include <sound/core.h>
#include <sound/pcm.h>
#include <sound/pcm_params.h>
#include <sound/soc.h>
#include <sound/dmaengine_pcm.h>
#include <linux/edma.h>

#include "edma-pcm.h"

static const struct snd_pcm_hardware edma_pcm_hardware = {
	.info			= SNDRV_PCM_INFO_MMAP |
				  SNDRV_PCM_INFO_MMAP_VALID |
				  SNDRV_PCM_INFO_PAUSE | SNDRV_PCM_INFO_RESUME |
				  SNDRV_PCM_INFO_NO_PERIOD_WAKEUP |
				  SNDRV_PCM_INFO_INTERLEAVED,
	.buffer_bytes_max	= 128 * 1024,
	.period_bytes_min	= 32,
	.period_bytes_max	= 64 * 1024,
	.periods_min		= 2,
	.periods_max		= 19, /* Limit by edma dmaengine driver */
};

static const struct snd_dmaengine_pcm_config edma_dmaengine_pcm_config = {
	.pcm_hardware = &edma_pcm_hardware,
	.prepare_slave_config = snd_dmaengine_pcm_prepare_slave_config,
	.compat_filter_fn = edma_filter_fn,
	.prealloc_buffer_size = 128 * 1024,
};

int edma_pcm_platform_register(struct device *dev)
{
	return devm_snd_dmaengine_pcm_register(dev, &edma_dmaengine_pcm_config,
					SND_DMAENGINE_PCM_FLAG_COMPAT);
}
EXPORT_SYMBOL_GPL(edma_pcm_platform_register);

MODULE_AUTHOR("Peter Ujfalusi <peter.ujfalusi@ti.com>");
MODULE_DESCRIPTION("eDMA PCM ASoC platform driver");
MODULE_LICENSE("GPL");
/net-next.git/commit/sound/soc/tegra?id=3895dbf8985f656675b5bde610723a29cbce3fa7'>commit</a><a href='/cgit.cgi/linux/net-next.git/diff/sound/soc/tegra?id=3895dbf8985f656675b5bde610723a29cbce3fa7'>diff</a></td><td class='form'><form class='right' method='get' action='/cgit.cgi/linux/net-next.git/log/sound/soc/tegra'>
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<div class='path'>path: <a href='/cgit.cgi/linux/net-next.git/commit/?id=3895dbf8985f656675b5bde610723a29cbce3fa7'>root</a>/<a href='/cgit.cgi/linux/net-next.git/commit/sound?id=3895dbf8985f656675b5bde610723a29cbce3fa7'>sound</a>/<a href='/cgit.cgi/linux/net-next.git/commit/sound/soc?id=3895dbf8985f656675b5bde610723a29cbce3fa7'>soc</a>/<a href='/cgit.cgi/linux/net-next.git/commit/sound/soc/tegra?id=3895dbf8985f656675b5bde610723a29cbce3fa7'>tegra</a></div><div class='content'><div class='cgit-panel'><b>diff options</b><form method='get'><input type='hidden' name='id' value='3895dbf8985f656675b5bde610723a29cbce3fa7'/><table><tr><td colspan='2'/></tr><tr><td class='label'>context:</td><td class='ctrl'><select name='context' onchange='this.form.submit();'><option value='1'>1</option><option value='2'>2</option><option value='3' selected='selected'>3</option><option value='4'>4</option><option value='5'>5</option><option value='6'>6</option><option value='7'>7</option><option value='8'>8</option><option value='9'>9</option><option value='10'>10</option><option value='15'>15</option><option value='20'>20</option><option value='25'>25</option><option value='30'>30</option><option value='35'>35</option><option value='40'>40</option></select></td></tr><tr><td class='label'>space:</td><td class='ctrl'><select name='ignorews' onchange='this.form.submit();'><option value='0' selected='selected'>include</option><option value='1'>ignore</option></select></td></tr><tr><td class='label'>mode:</td><td class='ctrl'><select name='dt' onchange='this.form.submit();'><option value='0' selected='selected'>unified</option><option value='1'>ssdiff</option><option value='2'>stat only</option></select></td></tr><tr><td/><td class='ctrl'><noscript><input type='submit' value='reload'/></noscript></td></tr></table></form></div><table summary='commit info' class='commit-info'>
<tr><th>author</th><td>Eric W. Biederman &lt;ebiederm@xmission.com&gt;</td><td class='right'>2017-01-03 14:18:43 +1300</td></tr>
<tr><th>committer</th><td>Eric W. Biederman &lt;ebiederm@xmission.com&gt;</td><td class='right'>2017-01-10 13:34:43 +1300</td></tr>
<tr><th>commit</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/sound/soc/tegra?id=3895dbf8985f656675b5bde610723a29cbce3fa7'>3895dbf8985f656675b5bde610723a29cbce3fa7</a> (<a href='/cgit.cgi/linux/net-next.git/patch/sound/soc/tegra?id=3895dbf8985f656675b5bde610723a29cbce3fa7'>patch</a>)</td></tr>
<tr><th>tree</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/tree/?id=3895dbf8985f656675b5bde610723a29cbce3fa7'>91d4517f09918fd573998eb40b8f35f08ed1c470</a> /<a href='/cgit.cgi/linux/net-next.git/tree/sound/soc/tegra?id=3895dbf8985f656675b5bde610723a29cbce3fa7'>sound/soc/tegra</a></td></tr>
<tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/sound/soc/tegra?id=0c744ea4f77d72b3dcebb7a8f2684633ec79be88'>0c744ea4f77d72b3dcebb7a8f2684633ec79be88</a> (<a href='/cgit.cgi/linux/net-next.git/diff/sound/soc/tegra?id=3895dbf8985f656675b5bde610723a29cbce3fa7&amp;id2=0c744ea4f77d72b3dcebb7a8f2684633ec79be88'>diff</a>)</td></tr></table>
<div class='commit-subject'>mnt: Protect the mountpoint hashtable with mount_lock</div><div class='commit-msg'>Protecting the mountpoint hashtable with namespace_sem was sufficient
until a call to umount_mnt was added to mntput_no_expire.  At which
point it became possible for multiple calls of put_mountpoint on
the same hash chain to happen on the same time.

Kristen Johansen &lt;kjlx@templeofstupid.com&gt; reported:
&gt; This can cause a panic when simultaneous callers of put_mountpoint
&gt; attempt to free the same mountpoint.  This occurs because some callers
&gt; hold the mount_hash_lock, while others hold the namespace lock.  Some
&gt; even hold both.
&gt;
&gt; In this submitter's case, the panic manifested itself as a GP fault in
&gt; put_mountpoint() when it called hlist_del() and attempted to dereference
&gt; a m_hash.pprev that had been poisioned by another thread.

Al Viro observed that the simple fix is to switch from using the namespace_sem
to the mount_lock to protect the mountpoint hash table.

I have taken Al's suggested patch moved put_mountpoint in pivot_root
(instead of taking mount_lock an additional time), and have replaced
new_mountpoint with get_mountpoint a function that does the hash table
lookup and addition under the mount_lock.   The introduction of get_mounptoint
ensures that only the mount_lock is needed to manipulate the mountpoint
hashtable.

d_set_mounted is modified to only set DCACHE_MOUNTED if it is not
already set.  This allows get_mountpoint to use the setting of
DCACHE_MOUNTED to ensure adding a struct mountpoint for a dentry
happens exactly once.

Cc: stable@vger.kernel.org
Fixes: ce07d891a089 ("mnt: Honor MNT_LOCKED when detaching mounts")
Reported-by: Krister Johansen &lt;kjlx@templeofstupid.com&gt;
Suggested-by: Al Viro &lt;viro@ZenIV.linux.org.uk&gt;
Acked-by: Al Viro &lt;viro@ZenIV.linux.org.uk&gt;
Signed-off-by: "Eric W. Biederman" &lt;ebiederm@xmission.com&gt;
</div><div class='diffstat-header'><a href='/cgit.cgi/linux/net-next.git/diff/?id=3895dbf8985f656675b5bde610723a29cbce3fa7'>Diffstat</a> (limited to 'sound/soc/tegra')</div><table summary='diffstat' class='diffstat'>