/*
 * Apple Onboard Audio driver for Toonie codec
 *
 * Copyright 2006 Johannes Berg <johannes@sipsolutions.net>
 *
 * GPL v2, can be found in COPYING.
 *
 *
 * This is a driver for the toonie codec chip. This chip is present
 * on the Mac Mini and is nothing but a DAC.
 */
#include <linux/delay.h>
#include <linux/module.h>
#include <linux/slab.h>
MODULE_AUTHOR("Johannes Berg <johannes@sipsolutions.net>");
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("toonie codec driver for snd-aoa");

#include "../aoa.h"
#include "../soundbus/soundbus.h"


#define PFX "snd-aoa-codec-toonie: "

struct toonie {
	struct aoa_codec	codec;
};
#define codec_to_toonie(c) container_of(c, struct toonie, codec)

static int toonie_dev_register(struct snd_device *dev)
{
	return 0;
}

static struct snd_device_ops ops = {
	.dev_register = toonie_dev_register,
};

static struct transfer_info toonie_transfers[] = {
	/* This thing *only* has analog output,
	 * the rates are taken from Info.plist
	 * from Darwin. */
	{
		.formats = SNDRV_PCM_FMTBIT_S16_BE |
			   SNDRV_PCM_FMTBIT_S24_BE,
		.rates = SNDRV_PCM_RATE_32000 |
			 SNDRV_PCM_RATE_44100 |
			 SNDRV_PCM_RATE_48000 |
			 SNDRV_PCM_RATE_88200 |
			 SNDRV_PCM_RATE_96000,
	},
	{}
};

static int toonie_usable(struct codec_info_item *cii,
			 struct transfer_info *ti,
			 struct transfer_info *out)
{
	return 1;
}

#ifdef CONFIG_PM
static int toonie_suspend(struct codec_info_item *cii, pm_message_t state)
{
	/* can we turn it off somehow? */
	return 0;
}

static int toonie_resume(struct codec_info_item *cii)
{
	return 0;
}
#endif /* CONFIG_PM */

static struct codec_info toonie_codec_info = {
	.transfers = toonie_transfers,
	.sysclock_factor = 256,
	.bus_factor = 64,
	.owner = THIS_MODULE,
	.usable = toonie_usable,
#ifdef CONFIG_PM
	.suspend = toonie_suspend,
	.resume = toonie_resume,
#endif
};

static int toonie_init_codec(struct aoa_codec *codec)
{
	struct toonie *toonie = codec_to_toonie(codec);

	/* nothing connected? what a joke! */
	if (toonie->codec.connected != 1)
		return -ENOTCONN;

	if (aoa_snd_device_new(SNDRV_DEV_CODEC, toonie, &ops)) {
		printk(KERN_ERR PFX "failed to create toonie snd device!\n");
		return -ENODEV;
	}

	if (toonie->codec.soundbus_dev->attach_codec(toonie->codec.soundbus_dev,
						     aoa_get_card(),
						     &toonie_codec_info, toonie)) {
		printk(KERN_ERR PFX "error creating toonie pcm\n");
		snd_device_free(aoa_get_card(), toonie);
		return -ENODEV;
	}

	return 0;
}

static void toonie_exit_codec(struct aoa_codec *codec)
{
	struct toonie *toonie = codec_to_toonie(codec);

	if (!toonie->codec.soundbus_dev) {
		printk(KERN_ERR PFX "toonie_exit_codec called without soundbus_dev!\n");
		return;
	}
	toonie->codec.soundbus_dev->detach_codec(toonie->codec.soundbus_dev, toonie);
}

static struct toonie *toonie;

static int __init toonie_init(void)
{
	toonie = kzalloc(sizeof(struct toonie), GFP_KERNEL);

	if (!toonie)
		return -ENOMEM;

	strlcpy(toonie->codec.name, "toonie", sizeof(toonie->codec.name));
	toonie->codec.owner = THIS_MODULE;
	toonie->codec.init = toonie_init_codec;
	toonie->codec.exit = toonie_exit_codec;

	if (aoa_codec_register(&toonie->codec)) {
		kfree(toonie);
		return -EINVAL;
	}

	return 0;
}

static void __exit toonie_exit(void)
{
	aoa_codec_unregister(&toonie->codec);
	kfree(toonie);
}

module_init(toonie_init);
module_exit(toonie_exit);
;id=966d2b04e070bc040319aaebfec09e0144dc3341'>discover.c</a></div><div class='content'><div class='cgit-panel'><b>diff options</b><form method='get'><input type='hidden' name='h' value='nds-private-remove'/><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/net/tipc/discover.c?h=nds-private-remove&amp;id=966d2b04e070bc040319aaebfec09e0144dc3341'>966d2b04e070bc040319aaebfec09e0144dc3341</a> (<a href='/cgit.cgi/linux/net-next.git/patch/net/tipc/discover.c?id=966d2b04e070bc040319aaebfec09e0144dc3341'>patch</a>)</td></tr>
<tr><th>tree</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/tree/?h=nds-private-remove&amp;id=966d2b04e070bc040319aaebfec09e0144dc3341'>4b96156e3d1dd4dfd6039b7c219c9dc4616da52d</a> /<a href='/cgit.cgi/linux/net-next.git/tree/net/tipc/discover.c?h=nds-private-remove&amp;id=966d2b04e070bc040319aaebfec09e0144dc3341'>net/tipc/discover.c</a></td></tr>
<tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/net/tipc/discover.c?h=nds-private-remove&amp;id=1b1bc42c1692e9b62756323c675a44cb1a1f9dbd'>1b1bc42c1692e9b62756323c675a44cb1a1f9dbd</a> (<a href='/cgit.cgi/linux/net-next.git/diff/net/tipc/discover.c?h=nds-private-remove&amp;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/?h=nds-private-remove&amp;id=966d2b04e070bc040319aaebfec09e0144dc3341'>Diffstat</a> (limited to 'net/tipc/discover.c')</div><table summary='diffstat' class='diffstat'>