/*
 * Copyright (c) 2016 Qualcomm Atheros, Inc
 *
 * GPL v2
 *
 * Based on net/sched/sch_fq_codel.c
 */
#ifndef __NET_SCHED_FQ_IMPL_H
#define __NET_SCHED_FQ_IMPL_H

#include <net/fq.h>

/* functions that are embedded into includer */

static struct sk_buff *fq_flow_dequeue(struct fq *fq,
				       struct fq_flow *flow)
{
	struct fq_tin *tin = flow->tin;
	struct fq_flow *i;
	struct sk_buff *skb;

	lockdep_assert_held(&fq->lock);

	skb = __skb_dequeue(&flow->queue);
	if (!skb)
		return NULL;

	tin->backlog_bytes -= skb->len;
	tin->backlog_packets--;
	flow->backlog -= skb->len;
	fq->backlog--;
	fq->memory_usage -= skb->truesize;

	if (flow->backlog == 0) {
		list_del_init(&flow->backlogchain);
	} else {
		i = flow;

		list_for_each_entry_continue(i, &fq->backlogs, backlogchain)
			if (i->backlog < flow->backlog)
				break;

		list_move_tail(&flow->backlogchain,
			       &i->backlogchain);
	}

	return skb;
}

static struct sk_buff *fq_tin_dequeue(struct fq *fq,
				      struct fq_tin *tin,
				      fq_tin_dequeue_t dequeue_func)
{
	struct fq_flow *flow;
	struct list_head *head;
	struct sk_buff *skb;

	lockdep_assert_held(&fq->lock);

begin:
	head = &tin->new_flows;
	if (list_empty(head)) {
		head = &tin->old_flows;
		if (list_empty(head))
			return NULL;
	}

	flow = list_first_entry(head, struct fq_flow, flowchain);

	if (flow->deficit <= 0) {
		flow->deficit += fq->quantum;
		list_move_tail(&flow->flowchain,
			       &tin->old_flows);
		goto begin;
	}

	skb = dequeue_func(fq, tin, flow);
	if (!skb) {
		/* force a pass through old_flows to prevent starvation */
		if ((head == &tin->new_flows) &&
		    !list_empty(&tin->old_flows)) {
			list_move_tail(&flow->flowchain, &tin->old_flows);
		} else {
			list_del_init(&flow->flowchain);
			flow->tin = NULL;
		}
		goto begin;
	}

	flow->deficit -= skb->len;
	tin->tx_bytes += skb->len;
	tin->tx_packets++;

	return skb;
}

static struct fq_flow *fq_flow_classify(struct fq *fq,
					struct fq_tin *tin,
					struct sk_buff *skb,
					fq_flow_get_default_t get_default_func)
{
	struct fq_flow *flow;
	u32 hash;
	u32 idx;

	lockdep_assert_held(&fq->lock);

	hash = skb_get_hash_perturb(skb, fq->perturbation);
	idx = reciprocal_scale(hash, fq->flows_cnt);
	flow = &fq->flows[idx];

	if (flow->tin && flow->tin != tin) {
		flow = get_default_func(fq, tin, idx, skb);
		tin->collisions++;
		fq->collisions++;
	}

	if (!flow->tin)
		tin->flows++;

	return flow;
}

static void fq_recalc_backlog(struct fq *fq,
			      struct fq_tin *tin,
			      struct fq_flow *flow)
{
	struct fq_flow *i;

	if (list_empty(&flow->backlogchain))
		list_add_tail(&flow->backlogchain, &fq->backlogs);

	i = flow;
	list_for_each_entry_continue_reverse(i, &fq->backlogs,
					     backlogchain)
		if (i->backlog > flow->backlog)
			break;

	list_move(&flow->backlogchain, &i->backlogchain);
}

static void fq_tin_enqueue(struct fq *fq,
			   struct fq_tin *tin,
			   struct sk_buff *skb,
			   fq_skb_free_t free_func,
			   fq_flow_get_default_t get_default_func)
{
	struct fq_flow *flow;

	lockdep_assert_held(&fq->lock);

	flow = fq_flow_classify(fq, tin, skb, get_default_func);

	flow->tin = tin;
	flow->backlog += skb->len;
	tin->backlog_bytes += skb->len;
	tin->backlog_packets++;
	fq->memory_usage += skb->truesize;
	fq->backlog++;

	fq_recalc_backlog(fq, tin, flow);

	if (list_empty(&flow->flowchain)) {
		flow->deficit = fq->quantum;
		list_add_tail(&flow->flowchain,
			      &tin->new_flows);
	}

	__skb_queue_tail(&flow->queue, skb);

	if (fq->backlog > fq->limit || fq->memory_usage > fq->memory_limit) {
		flow = list_first_entry_or_null(&fq->backlogs,
						struct fq_flow,
						backlogchain);
		if (!flow)
			return;

		skb = fq_flow_dequeue(fq, flow);
		if (!skb)
			return;

		free_func(fq, flow->tin, flow, skb);

		flow->tin->overlimit++;
		fq->overlimit++;
		if (fq->memory_usage > fq->memory_limit)
			fq->overmemory++;
	}
}

static void fq_flow_reset(struct fq *fq,
			  struct fq_flow *flow,
			  fq_skb_free_t free_func)
{
	struct sk_buff *skb;

	while ((skb = fq_flow_dequeue(fq, flow)))
		free_func(fq, flow->tin, flow, skb);

	if (!list_empty(&flow->flowchain))
		list_del_init(&flow->flowchain);

	if (!list_empty(&flow->backlogchain))
		list_del_init(&flow->backlogchain);

	flow->tin = NULL;

	WARN_ON_ONCE(flow->backlog);
}

static void fq_tin_reset(struct fq *fq,
			 struct fq_tin *tin,
			 fq_skb_free_t free_func)
{
	struct list_head *head;
	struct fq_flow *flow;

	for (;;) {
		head = &tin->new_flows;
		if (list_empty(head)) {
			head = &tin->old_flows;
			if (list_empty(head))
				break;
		}

		flow = list_first_entry(head, struct fq_flow, flowchain);
		fq_flow_reset(fq, flow, free_func);
	}

	WARN_ON_ONCE(tin->backlog_bytes);
	WARN_ON_ONCE(tin->backlog_packets);
}

static void fq_flow_init(struct fq_flow *flow)
{
	INIT_LIST_HEAD(&flow->flowchain);
	INIT_LIST_HEAD(&flow->backlogchain);
	__skb_queue_head_init(&flow->queue);
}

static void fq_tin_init(struct fq_tin *tin)
{
	INIT_LIST_HEAD(&tin->new_flows);
	INIT_LIST_HEAD(&tin->old_flows);
}

static int fq_init(struct fq *fq, int flows_cnt)
{
	int i;

	memset(fq, 0, sizeof(fq[0]));
	INIT_LIST_HEAD(&fq->backlogs);
	spin_lock_init(&fq->lock);
	fq->flows_cnt = max_t(u32, flows_cnt, 1);
	fq->perturbation = prandom_u32();
	fq->quantum = 300;
	fq->limit = 8192;
	fq->memory_limit = 16 << 20; /* 16 MBytes */

	fq->flows = kcalloc(fq->flows_cnt, sizeof(fq->flows[0]), GFP_KERNEL);
	if (!fq->flows)
		return -ENOMEM;

	for (i = 0; i < fq->flows_cnt; i++)
		fq_flow_init(&fq->flows[i]);

	return 0;
}

static void fq_reset(struct fq *fq,
		     fq_skb_free_t free_func)
{
	int i;

	for (i = 0; i < fq->flows_cnt; i++)
		fq_flow_reset(fq, &fq->flows[i], free_func);

	kfree(fq->flows);
	fq->flows = NULL;
}

#endif
et/mip6.h?h=nds-private-remove&amp;id=c8f325a59cfc718d13a50fbc746ed9b415c25e92'>include/net/mip6.h</a></td></tr>
<tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/include/net/mip6.h?h=nds-private-remove&amp;id=bf29bddf0417a4783da3b24e8c9e017ac649326f'>bf29bddf0417a4783da3b24e8c9e017ac649326f</a> (<a href='/cgit.cgi/linux/net-next.git/diff/include/net/mip6.h?h=nds-private-remove&amp;id=c8f325a59cfc718d13a50fbc746ed9b415c25e92&amp;id2=bf29bddf0417a4783da3b24e8c9e017ac649326f'>diff</a>)</td></tr></table>
<div class='commit-subject'>efi/fdt: Avoid FDT manipulation after ExitBootServices()</div><div class='commit-msg'>Some AArch64 UEFI implementations disable the MMU in ExitBootServices(),
after which unaligned accesses to RAM are no longer supported.

Commit:

  abfb7b686a3e ("efi/libstub/arm*: Pass latest memory map to the kernel")

fixed an issue in the memory map handling of the stub FDT code, but
inadvertently created an issue with such firmware, by moving some
of the FDT manipulation to after the invocation of ExitBootServices().

Given that the stub's libfdt implementation uses the ordinary, accelerated
string functions, which rely on hardware handling of unaligned accesses,
manipulating the FDT with the MMU off may result in alignment faults.

So fix the situation by moving the update_fdt_memmap() call into the
callback function invoked by efi_exit_boot_services() right before it
calls the ExitBootServices() UEFI service (which is arguably a better
place for it anyway)

Note that disabling the MMU in ExitBootServices() is not compliant with
the UEFI spec, and carries great risk due to the fact that switching from
cached to uncached memory accesses halfway through compiler generated code
(i.e., involving a stack) can never be done in a way that is architecturally
safe.

Fixes: abfb7b686a3e ("efi/libstub/arm*: Pass latest memory map to the kernel")
Signed-off-by: Ard Biesheuvel &lt;ard.biesheuvel@linaro.org&gt;
Tested-by: Riku Voipio &lt;riku.voipio@linaro.org&gt;
Cc: &lt;stable@vger.kernel.org&gt;
Cc: mark.rutland@arm.com
Cc: linux-efi@vger.kernel.org
Cc: matt@codeblueprint.co.uk
Cc: leif.lindholm@linaro.org
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lkml.kernel.org/r/1485971102-23330-2-git-send-email-ard.biesheuvel@linaro.org
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</div><div class='diffstat-header'><a href='/cgit.cgi/linux/net-next.git/diff/?h=nds-private-remove&amp;id=c8f325a59cfc718d13a50fbc746ed9b415c25e92'>Diffstat</a> (limited to 'include/net/mip6.h')</div><table summary='diffstat' class='diffstat'>