/*
 * Phytec pcm030 driver for the PSC of the Freescale MPC52xx
 * configured as AC97 interface
 *
 * Copyright 2008 Jon Smirl, Digispeaker
 * Author: Jon Smirl <jonsmirl@gmail.com>
 *
 * This file is licensed under the terms of the GNU General Public License
 * version 2. This program is licensed "as is" without any warranty of any
 * kind, whether express or implied.
 */

#include <linux/init.h>
#include <linux/module.h>
#include <linux/device.h>
#include <linux/of_device.h>
#include <linux/of_platform.h>

#include <sound/soc.h>

#include "mpc5200_dma.h"

#define DRV_NAME "pcm030-audio-fabric"

struct pcm030_audio_data {
	struct snd_soc_card *card;
	struct platform_device *codec_device;
};

static struct snd_soc_dai_link pcm030_fabric_dai[] = {
{
	.name = "AC97.0",
	.stream_name = "AC97 Analog",
	.codec_dai_name = "wm9712-hifi",
	.cpu_dai_name = "mpc5200-psc-ac97.0",
	.codec_name = "wm9712-codec",
},
{
	.name = "AC97.1",
	.stream_name = "AC97 IEC958",
	.codec_dai_name = "wm9712-aux",
	.cpu_dai_name = "mpc5200-psc-ac97.1",
	.codec_name = "wm9712-codec",
},
};

static struct snd_soc_card pcm030_card = {
	.name = "pcm030",
	.owner = THIS_MODULE,
	.dai_link = pcm030_fabric_dai,
	.num_links = ARRAY_SIZE(pcm030_fabric_dai),
};

static int pcm030_fabric_probe(struct platform_device *op)
{
	struct device_node *np = op->dev.of_node;
	struct device_node *platform_np;
	struct snd_soc_card *card = &pcm030_card;
	struct pcm030_audio_data *pdata;
	int ret;
	int i;

	if (!of_machine_is_compatible("phytec,pcm030"))
		return -ENODEV;

	pdata = devm_kzalloc(&op->dev, sizeof(struct pcm030_audio_data),
			     GFP_KERNEL);
	if (!pdata)
		return -ENOMEM;

	card->dev = &op->dev;

	pdata->card = card;

	platform_np = of_parse_phandle(np, "asoc-platform", 0);
	if (!platform_np) {
		dev_err(&op->dev, "ac97 not registered\n");
		return -ENODEV;
	}

	for (i = 0; i < card->num_links; i++)
		card->dai_link[i].platform_of_node = platform_np;

	ret = request_module("snd-soc-wm9712");
	if (ret)
		dev_err(&op->dev, "request_module returned: %d\n", ret);

	pdata->codec_device = platform_device_alloc("wm9712-codec", -1);
	if (!pdata->codec_device)
		dev_err(&op->dev, "platform_device_alloc() failed\n");

	ret = platform_device_add(pdata->codec_device);
	if (ret)
		dev_err(&op->dev, "platform_device_add() failed: %d\n", ret);

	ret = snd_soc_register_card(card);
	if (ret)
		dev_err(&op->dev, "snd_soc_register_card() failed: %d\n", ret);

	platform_set_drvdata(op, pdata);

	return ret;
}

static int pcm030_fabric_remove(struct platform_device *op)
{
	struct pcm030_audio_data *pdata = platform_get_drvdata(op);
	int ret;

	ret = snd_soc_unregister_card(pdata->card);
	platform_device_unregister(pdata->codec_device);

	return ret;
}

static const struct of_device_id pcm030_audio_match[] = {
	{ .compatible = "phytec,pcm030-audio-fabric", },
	{}
};
MODULE_DEVICE_TABLE(of, pcm030_audio_match);

static struct platform_driver pcm030_fabric_driver = {
	.probe		= pcm030_fabric_probe,
	.remove		= pcm030_fabric_remove,
	.driver		= {
		.name	= DRV_NAME,
		.of_match_table    = pcm030_audio_match,
	},
};

module_platform_driver(pcm030_fabric_driver);


MODULE_AUTHOR("Jon Smirl <jonsmirl@gmail.com>");
MODULE_DESCRIPTION(DRV_NAME ": mpc5200 pcm030 fabric driver");
MODULE_LICENSE("GPL");

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/fs/xfs/libxfs/xfs_inode_buf.h?id=966d2b04e070bc040319aaebfec09e0144dc3341'>966d2b04e070bc040319aaebfec09e0144dc3341</a> (<a href='/cgit.cgi/linux/net-next.git/patch/fs/xfs/libxfs/xfs_inode_buf.h?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/fs/xfs/libxfs/xfs_inode_buf.h?id=966d2b04e070bc040319aaebfec09e0144dc3341'>fs/xfs/libxfs/xfs_inode_buf.h</a></td></tr>
<tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/fs/xfs/libxfs/xfs_inode_buf.h?id=1b1bc42c1692e9b62756323c675a44cb1a1f9dbd'>1b1bc42c1692e9b62756323c675a44cb1a1f9dbd</a> (<a href='/cgit.cgi/linux/net-next.git/diff/fs/xfs/libxfs/xfs_inode_buf.h?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 'fs/xfs/libxfs/xfs_inode_buf.h')</div><table summary='diffstat' class='diffstat'>