/*
 * linux/sound/arm/pxa2xx-pcm.c -- ALSA PCM interface for the Intel PXA2xx chip
 *
 * Author:	Nicolas Pitre
 * Created:	Nov 30, 2004
 * Copyright:	(C) 2004 MontaVista Software, Inc.
 *
 * 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.
 */

#include <linux/dma-mapping.h>
#include <linux/module.h>
#include <linux/dmaengine.h>
#include <linux/of.h>

#include <sound/core.h>
#include <sound/soc.h>
#include <sound/pxa2xx-lib.h>
#include <sound/dmaengine_pcm.h>

#include "../../arm/pxa2xx-pcm.h"

static int pxa2xx_pcm_hw_params(struct snd_pcm_substream *substream,
	struct snd_pcm_hw_params *params)
{
	struct snd_soc_pcm_runtime *rtd = substream->private_data;
	struct snd_dmaengine_dai_dma_data *dma;

	dma = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream);

	/* return if this is a bufferless transfer e.g.
	 * codec <--> BT codec or GSM modem -- lg FIXME */
	if (!dma)
		return 0;

	return __pxa2xx_pcm_hw_params(substream, params);
}

static int pxa2xx_pcm_hw_free(struct snd_pcm_substream *substream)
{
	__pxa2xx_pcm_hw_free(substream);

	return 0;
}

static struct snd_pcm_ops pxa2xx_pcm_ops = {
	.open		= __pxa2xx_pcm_open,
	.close		= __pxa2xx_pcm_close,
	.ioctl		= snd_pcm_lib_ioctl,
	.hw_params	= pxa2xx_pcm_hw_params,
	.hw_free	= pxa2xx_pcm_hw_free,
	.prepare	= __pxa2xx_pcm_prepare,
	.trigger	= pxa2xx_pcm_trigger,
	.pointer	= pxa2xx_pcm_pointer,
	.mmap		= pxa2xx_pcm_mmap,
};

static int pxa2xx_soc_pcm_new(struct snd_soc_pcm_runtime *rtd)
{
	struct snd_card *card = rtd->card->snd_card;
	struct snd_pcm *pcm = rtd->pcm;
	int ret;

	ret = dma_coerce_mask_and_coherent(card->dev, DMA_BIT_MASK(32));
	if (ret)
		return ret;

	if (pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream) {
		ret = pxa2xx_pcm_preallocate_dma_buffer(pcm,
			SNDRV_PCM_STREAM_PLAYBACK);
		if (ret)
			goto out;
	}

	if (pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream) {
		ret = pxa2xx_pcm_preallocate_dma_buffer(pcm,
			SNDRV_PCM_STREAM_CAPTURE);
		if (ret)
			goto out;
	}
 out:
	return ret;
}

static struct snd_soc_platform_driver pxa2xx_soc_platform = {
	.ops 	= &pxa2xx_pcm_ops,
	.pcm_new	= pxa2xx_soc_pcm_new,
	.pcm_free	= pxa2xx_pcm_free_dma_buffers,
};

static int pxa2xx_soc_platform_probe(struct platform_device *pdev)
{
	return devm_snd_soc_register_platform(&pdev->dev, &pxa2xx_soc_platform);
}

#ifdef CONFIG_OF
static const struct of_device_id snd_soc_pxa_audio_match[] = {
	{ .compatible   = "mrvl,pxa-pcm-audio" },
	{ }
};
MODULE_DEVICE_TABLE(of, snd_soc_pxa_audio_match);
#endif

static struct platform_driver pxa_pcm_driver = {
	.driver = {
		.name = "pxa-pcm-audio",
		.of_match_table = of_match_ptr(snd_soc_pxa_audio_match),
	},

	.probe = pxa2xx_soc_platform_probe,
};

module_platform_driver(pxa_pcm_driver);

MODULE_AUTHOR("Nicolas Pitre");
MODULE_DESCRIPTION("Intel PXA2xx PCM DMA module");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:pxa-pcm-audio");
1'>perf</a>/<a href='/cgit.cgi/linux/net-next.git/commit/tools/perf/ui?id=966d2b04e070bc040319aaebfec09e0144dc3341'>ui</a>/<a href='/cgit.cgi/linux/net-next.git/commit/tools/perf/ui/tui?id=966d2b04e070bc040319aaebfec09e0144dc3341'>tui</a>/<a href='/cgit.cgi/linux/net-next.git/commit/tools/perf/ui/tui/Build?id=966d2b04e070bc040319aaebfec09e0144dc3341'>Build</a></div><div class='content'><div class='cgit-panel'><b>diff options</b><form method='get'><input type='hidden' name='id' value='966d2b04e070bc040319aaebfec09e0144dc3341'/><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>Douglas Miller &lt;dougmill@linux.vnet.ibm.com&gt;</td><td class='right'>2017-01-28 06:42:20 -0600</td></tr>
<tr><th>committer</th><td>Tejun Heo &lt;tj@kernel.org&gt;</td><td class='right'>2017-01-28 07:49:42 -0500</td></tr>
<tr><th>commit</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/tools/perf/ui/tui/Build?id=966d2b04e070bc040319aaebfec09e0144dc3341'>966d2b04e070bc040319aaebfec09e0144dc3341</a> (<a href='/cgit.cgi/linux/net-next.git/patch/tools/perf/ui/tui/Build?id=966d2b04e070bc040319aaebfec09e0144dc3341'>patch</a>)</td></tr>
<tr><th>tree</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/tree/?id=966d2b04e070bc040319aaebfec09e0144dc3341'>4b96156e3d1dd4dfd6039b7c219c9dc4616da52d</a> /<a href='/cgit.cgi/linux/net-next.git/tree/tools/perf/ui/tui/Build?id=966d2b04e070bc040319aaebfec09e0144dc3341'>tools/perf/ui/tui/Build</a></td></tr>
<tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/tools/perf/ui/tui/Build?id=1b1bc42c1692e9b62756323c675a44cb1a1f9dbd'>1b1bc42c1692e9b62756323c675a44cb1a1f9dbd</a> (<a href='/cgit.cgi/linux/net-next.git/diff/tools/perf/ui/tui/Build?id=966d2b04e070bc040319aaebfec09e0144dc3341&amp;id2=1b1bc42c1692e9b62756323c675a44cb1a1f9dbd'>diff</a>)</td></tr></table>
<div class='commit-subject'>percpu-refcount: fix reference leak during percpu-atomic transition</div><div class='commit-msg'>percpu_ref_tryget() and percpu_ref_tryget_live() should return
"true" IFF they acquire a reference. But the return value from
atomic_long_inc_not_zero() is a long and may have high bits set,
e.g. PERCPU_COUNT_BIAS, and the return value of the tryget routines
is bool so the reference may actually be acquired but the routines
return "false" which results in a reference leak since the caller
assumes it does not need to do a corresponding percpu_ref_put().

This was seen when performing CPU hotplug during I/O, as hangs in
blk_mq_freeze_queue_wait where percpu_ref_kill (blk_mq_freeze_queue_start)
raced with percpu_ref_tryget (blk_mq_timeout_work).
Sample stack trace:

__switch_to+0x2c0/0x450
__schedule+0x2f8/0x970
schedule+0x48/0xc0
blk_mq_freeze_queue_wait+0x94/0x120
blk_mq_queue_reinit_work+0xb8/0x180
blk_mq_queue_reinit_prepare+0x84/0xa0
cpuhp_invoke_callback+0x17c/0x600
cpuhp_up_callbacks+0x58/0x150
_cpu_up+0xf0/0x1c0
do_cpu_up+0x120/0x150
cpu_subsys_online+0x64/0xe0
device_online+0xb4/0x120
online_store+0xb4/0xc0
dev_attr_store+0x68/0xa0
sysfs_kf_write+0x80/0xb0
kernfs_fop_write+0x17c/0x250
__vfs_write+0x6c/0x1e0
vfs_write+0xd0/0x270
SyS_write+0x6c/0x110
system_call+0x38/0xe0

Examination of the queue showed a single reference (no PERCPU_COUNT_BIAS,
and __PERCPU_REF_DEAD, __PERCPU_REF_ATOMIC set) and no requests.
However, conditions at the time of the race are count of PERCPU_COUNT_BIAS + 0
and __PERCPU_REF_DEAD and __PERCPU_REF_ATOMIC set.

The fix is to make the tryget routines use an actual boolean internally instead
of the atomic long result truncated to a int.

Fixes: e625305b3907 percpu-refcount: make percpu_ref based on longs instead of ints
Link: https://bugzilla.kernel.org/show_bug.cgi?id=190751
Signed-off-by: Douglas Miller &lt;dougmill@linux.vnet.ibm.com&gt;
Reviewed-by: Jens Axboe &lt;axboe@fb.com&gt;
Signed-off-by: Tejun Heo &lt;tj@kernel.org&gt;
Fixes: e625305b3907 ("percpu-refcount: make percpu_ref based on longs instead of ints")
Cc: stable@vger.kernel.org # v3.18+
</div><div class='diffstat-header'><a href='/cgit.cgi/linux/net-next.git/diff/?id=966d2b04e070bc040319aaebfec09e0144dc3341'>Diffstat</a> (limited to 'tools/perf/ui/tui/Build')</div><table summary='diffstat' class='diffstat'>