/*
 * Copyright (C) 2010, 2015 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
 *
 * membarrier system call
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * 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/syscalls.h>
#include <linux/membarrier.h>

/*
 * Bitmask made from a "or" of all commands within enum membarrier_cmd,
 * except MEMBARRIER_CMD_QUERY.
 */
#define MEMBARRIER_CMD_BITMASK	(MEMBARRIER_CMD_SHARED)

/**
 * sys_membarrier - issue memory barriers on a set of threads
 * @cmd:   Takes command values defined in enum membarrier_cmd.
 * @flags: Currently needs to be 0. For future extensions.
 *
 * If this system call is not implemented, -ENOSYS is returned. If the
 * command specified does not exist, or if the command argument is invalid,
 * this system call returns -EINVAL. For a given command, with flags argument
 * set to 0, this system call is guaranteed to always return the same value
 * until reboot.
 *
 * All memory accesses performed in program order from each targeted thread
 * is guaranteed to be ordered with respect to sys_membarrier(). If we use
 * the semantic "barrier()" to represent a compiler barrier forcing memory
 * accesses to be performed in program order across the barrier, and
 * smp_mb() to represent explicit memory barriers forcing full memory
 * ordering across the barrier, we have the following ordering table for
 * each pair of barrier(), sys_membarrier() and smp_mb():
 *
 * The pair ordering is detailed as (O: ordered, X: not ordered):
 *
 *                        barrier()   smp_mb() sys_membarrier()
 *        barrier()          X           X            O
 *        smp_mb()           X           O            O
 *        sys_membarrier()   O           O            O
 */
SYSCALL_DEFINE2(membarrier, int, cmd, int, flags)
{
	if (unlikely(flags))
		return -EINVAL;
	switch (cmd) {
	case MEMBARRIER_CMD_QUERY:
		return MEMBARRIER_CMD_BITMASK;
	case MEMBARRIER_CMD_SHARED:
		if (num_online_cpus() > 1)
			synchronize_sched();
		return 0;
	default:
		return -EINVAL;
	}
}
t/log/sound/pci/ctxfi/cttimer.h'>
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</td></tr></table>
<div class='path'>path: <a href='/cgit.cgi/linux/net-next.git/commit/?h=nds-private-remove&amp;id=0a019a28e0ca0af7dc2691d1a9527960b07ad2bb'>root</a>/<a href='/cgit.cgi/linux/net-next.git/commit/sound?h=nds-private-remove&amp;id=0a019a28e0ca0af7dc2691d1a9527960b07ad2bb'>sound</a>/<a href='/cgit.cgi/linux/net-next.git/commit/sound/pci?h=nds-private-remove&amp;id=0a019a28e0ca0af7dc2691d1a9527960b07ad2bb'>pci</a>/<a href='/cgit.cgi/linux/net-next.git/commit/sound/pci/ctxfi?h=nds-private-remove&amp;id=0a019a28e0ca0af7dc2691d1a9527960b07ad2bb'>ctxfi</a>/<a href='/cgit.cgi/linux/net-next.git/commit/sound/pci/ctxfi/cttimer.h?h=nds-private-remove&amp;id=0a019a28e0ca0af7dc2691d1a9527960b07ad2bb'>cttimer.h</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='0a019a28e0ca0af7dc2691d1a9527960b07ad2bb'/><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>Olof Johansson &lt;olof@lixom.net&gt;</td><td class='right'>2017-01-29 21:00:48 -0800</td></tr>
<tr><th>committer</th><td>Olof Johansson &lt;olof@lixom.net&gt;</td><td class='right'>2017-01-29 21:00:48 -0800</td></tr>
<tr><th>commit</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/sound/pci/ctxfi/cttimer.h?h=nds-private-remove&amp;id=0a019a28e0ca0af7dc2691d1a9527960b07ad2bb'>0a019a28e0ca0af7dc2691d1a9527960b07ad2bb</a> (<a href='/cgit.cgi/linux/net-next.git/patch/sound/pci/ctxfi/cttimer.h?id=0a019a28e0ca0af7dc2691d1a9527960b07ad2bb'>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=0a019a28e0ca0af7dc2691d1a9527960b07ad2bb'>5ee1db9aacacd6af6701fb290e8a294ef3cc2bf2</a> /<a href='/cgit.cgi/linux/net-next.git/tree/sound/pci/ctxfi/cttimer.h?h=nds-private-remove&amp;id=0a019a28e0ca0af7dc2691d1a9527960b07ad2bb'>sound/pci/ctxfi/cttimer.h</a></td></tr>
<tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/sound/pci/ctxfi/cttimer.h?h=nds-private-remove&amp;id=ec026b5020688a8bde5fae9a69ae3c59b66ba3ae'>ec026b5020688a8bde5fae9a69ae3c59b66ba3ae</a> (<a href='/cgit.cgi/linux/net-next.git/diff/sound/pci/ctxfi/cttimer.h?h=nds-private-remove&amp;id=0a019a28e0ca0af7dc2691d1a9527960b07ad2bb&amp;id2=ec026b5020688a8bde5fae9a69ae3c59b66ba3ae'>diff</a>)</td></tr><tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/sound/pci/ctxfi/cttimer.h?h=nds-private-remove&amp;id=8413299cb3933dade6186bbee8363f190032107e'>8413299cb3933dade6186bbee8363f190032107e</a> (<a href='/cgit.cgi/linux/net-next.git/diff/sound/pci/ctxfi/cttimer.h?h=nds-private-remove&amp;id=0a019a28e0ca0af7dc2691d1a9527960b07ad2bb&amp;id2=8413299cb3933dade6186bbee8363f190032107e'>diff</a>)</td></tr></table>
<div class='commit-subject'>Merge tag 'sti-dt-for-v4.10-rc' of git://git.kernel.org/pub/scm/linux/kernel/git/pchotard/sti into fixes</div><div class='commit-msg'>STi DT fix:

Since v4.10-rc1, xhci is complaining in loop with :
    [  801.953836] usb usb6-port1: Cannot enable. Maybe the USB cable is bad?
    [  801.960455] xhci-hcd xhci-hcd.0.auto: Cannot set link state.
    [  801.966611] usb usb6-port1: cannot disable (err = -32)

set property "snps,dis_u3_susphy_quirk" in DT fix it.

* tag 'sti-dt-for-v4.10-rc' of git://git.kernel.org/pub/scm/linux/kernel/git/pchotard/sti:
  ARM: dts: STiH407-family: set snps,dis_u3_susphy_quirk

Signed-off-by: Olof Johansson &lt;olof@lixom.net&gt;
</div><div class='diffstat-header'><a href='/cgit.cgi/linux/net-next.git/diff/?h=nds-private-remove&amp;id=0a019a28e0ca0af7dc2691d1a9527960b07ad2bb'>Diffstat</a> (limited to 'sound/pci/ctxfi/cttimer.h')</div><table summary='diffstat' class='diffstat'>