/*
 *  net/dccp/qpolicy.c
 *
 *  Policy-based packet dequeueing interface for DCCP.
 *
 *  Copyright (c) 2008 Tomasz Grobelny <tomasz@grobelny.oswiecenia.net>
 *
 *  This program is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU General Public License v2
 *  as published by the Free Software Foundation.
 */
#include "dccp.h"

/*
 *	Simple Dequeueing Policy:
 *	If tx_qlen is different from 0, enqueue up to tx_qlen elements.
 */
static void qpolicy_simple_push(struct sock *sk, struct sk_buff *skb)
{
	skb_queue_tail(&sk->sk_write_queue, skb);
}

static bool qpolicy_simple_full(struct sock *sk)
{
	return dccp_sk(sk)->dccps_tx_qlen &&
	       sk->sk_write_queue.qlen >= dccp_sk(sk)->dccps_tx_qlen;
}

static struct sk_buff *qpolicy_simple_top(struct sock *sk)
{
	return skb_peek(&sk->sk_write_queue);
}

/*
 *	Priority-based Dequeueing Policy:
 *	If tx_qlen is different from 0 and the queue has reached its upper bound
 *	of tx_qlen elements, replace older packets lowest-priority-first.
 */
static struct sk_buff *qpolicy_prio_best_skb(struct sock *sk)
{
	struct sk_buff *skb, *best = NULL;

	skb_queue_walk(&sk->sk_write_queue, skb)
		if (best == NULL || skb->priority > best->priority)
			best = skb;
	return best;
}

static struct sk_buff *qpolicy_prio_worst_skb(struct sock *sk)
{
	struct sk_buff *skb, *worst = NULL;

	skb_queue_walk(&sk->sk_write_queue, skb)
		if (worst == NULL || skb->priority < worst->priority)
			worst = skb;
	return worst;
}

static bool qpolicy_prio_full(struct sock *sk)
{
	if (qpolicy_simple_full(sk))
		dccp_qpolicy_drop(sk, qpolicy_prio_worst_skb(sk));
	return false;
}

/**
 * struct dccp_qpolicy_operations  -  TX Packet Dequeueing Interface
 * @push: add a new @skb to the write queue
 * @full: indicates that no more packets will be admitted
 * @top:  peeks at whatever the queueing policy defines as its `top'
 */
static struct dccp_qpolicy_operations {
	void		(*push)	(struct sock *sk, struct sk_buff *skb);
	bool		(*full) (struct sock *sk);
	struct sk_buff*	(*top)  (struct sock *sk);
	__be32		params;

} qpol_table[DCCPQ_POLICY_MAX] = {
	[DCCPQ_POLICY_SIMPLE] = {
		.push   = qpolicy_simple_push,
		.full   = qpolicy_simple_full,
		.top    = qpolicy_simple_top,
		.params = 0,
	},
	[DCCPQ_POLICY_PRIO] = {
		.push   = qpolicy_simple_push,
		.full   = qpolicy_prio_full,
		.top    = qpolicy_prio_best_skb,
		.params = DCCP_SCM_PRIORITY,
	},
};

/*
 *	Externally visible interface
 */
void dccp_qpolicy_push(struct sock *sk, struct sk_buff *skb)
{
	qpol_table[dccp_sk(sk)->dccps_qpolicy].push(sk, skb);
}

bool dccp_qpolicy_full(struct sock *sk)
{
	return qpol_table[dccp_sk(sk)->dccps_qpolicy].full(sk);
}

void dccp_qpolicy_drop(struct sock *sk, struct sk_buff *skb)
{
	if (skb != NULL) {
		skb_unlink(skb, &sk->sk_write_queue);
		kfree_skb(skb);
	}
}

struct sk_buff *dccp_qpolicy_top(struct sock *sk)
{
	return qpol_table[dccp_sk(sk)->dccps_qpolicy].top(sk);
}

struct sk_buff *dccp_qpolicy_pop(struct sock *sk)
{
	struct sk_buff *skb = dccp_qpolicy_top(sk);

	if (skb != NULL) {
		/* Clear any skb fields that we used internally */
		skb->priority = 0;
		skb_unlink(skb, &sk->sk_write_queue);
	}
	return skb;
}

bool dccp_qpolicy_param_ok(struct sock *sk, __be32 param)
{
	/* check if exactly one bit is set */
	if (!param || (param & (param - 1)))
		return false;
	return (qpol_table[dccp_sk(sk)->dccps_qpolicy].params & param) == param;
}
selftests?h=nds-private-remove&amp;id=4d191b1b63c209e37bf27938ef365244d3c41084'>selftests</a>/<a href='/cgit.cgi/linux/net-next.git/commit/tools/testing/selftests/ia64?h=nds-private-remove&amp;id=4d191b1b63c209e37bf27938ef365244d3c41084'>ia64</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='4d191b1b63c209e37bf27938ef365244d3c41084'/><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>Marc Zyngier &lt;marc.zyngier@arm.com&gt;</td><td class='right'>2017-01-17 14:21:56 +0000</td></tr>
<tr><th>committer</th><td>Bjorn Helgaas &lt;bhelgaas@google.com&gt;</td><td class='right'>2017-01-17 08:41:51 -0600</td></tr>
<tr><th>commit</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/tools/testing/selftests/ia64?h=nds-private-remove&amp;id=4d191b1b63c209e37bf27938ef365244d3c41084'>4d191b1b63c209e37bf27938ef365244d3c41084</a> (<a href='/cgit.cgi/linux/net-next.git/patch/tools/testing/selftests/ia64?id=4d191b1b63c209e37bf27938ef365244d3c41084'>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=4d191b1b63c209e37bf27938ef365244d3c41084'>f2ab6cdb65ddacdf2e7c019cd55e353f0c16b400</a> /<a href='/cgit.cgi/linux/net-next.git/tree/tools/testing/selftests/ia64?h=nds-private-remove&amp;id=4d191b1b63c209e37bf27938ef365244d3c41084'>tools/testing/selftests/ia64</a></td></tr>
<tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/tools/testing/selftests/ia64?h=nds-private-remove&amp;id=51ebfc92b72b4f7dac1ab45683bf56741e454b8c'>51ebfc92b72b4f7dac1ab45683bf56741e454b8c</a> (<a href='/cgit.cgi/linux/net-next.git/diff/tools/testing/selftests/ia64?h=nds-private-remove&amp;id=4d191b1b63c209e37bf27938ef365244d3c41084&amp;id2=51ebfc92b72b4f7dac1ab45683bf56741e454b8c'>diff</a>)</td></tr></table>
<div class='commit-subject'>PCI/MSI: pci-xgene-msi: Fix CPU hotplug registration handling</div><div class='commit-msg'>The conversion to the new hotplug state machine introduced a regression
where a successful hotplug registration would be treated as an error,
effectively disabling the MSI driver forever.

Fix it by doing the proper check on the return value.

Fixes: 9c248f8896e6 ("PCI/xgene-msi: Convert to hotplug state machine")
Signed-off-by: Marc Zyngier &lt;marc.zyngier@arm.com&gt;
Signed-off-by: Bjorn Helgaas &lt;bhelgaas@google.com&gt;
Acked-by: Sebastian Andrzej Siewior &lt;bigeasy@linutronix.de&gt;
Tested-by: Duc Dang &lt;dhdang@apm.com&gt;
CC: Thomas Gleixner &lt;tglx@linutronix.de&gt;
CC: stable@vger.kernel.org</div><div class='diffstat-header'><a href='/cgit.cgi/linux/net-next.git/diff/?h=nds-private-remove&amp;id=4d191b1b63c209e37bf27938ef365244d3c41084'>Diffstat</a> (limited to 'tools/testing/selftests/ia64')</div><table summary='diffstat' class='diffstat'>