kernel: cake: add missing backport to 4.19 patches

2025-04-18 17:33:31 +00:00 · 2020-07-01 17:12:37 +08:00 · 2020-07-01 17:12:37 +08:00 · e4ecf8a5c0
commit e4ecf8a5c0
parent 6ea19a20b7
11 changed files with 1164 additions and 0 deletions
--- a/target/linux/generic/backport-4.19/390-v5.1-sch_cake-Make-the-dual-modes-fairer.patch
+++ b/target/linux/generic/backport-4.19/390-v5.1-sch_cake-Make-the-dual-modes-fairer.patch
@ -0,0 +1,217 @@
+From 712639929912c5eefb09facccb48d55b3f72c9f8 Mon Sep 17 00:00:00 2001
+From: George Amanakis <gamanakis@gmail.com>
+Date: Fri, 1 Mar 2019 16:04:05 +0100
+Subject: [PATCH] sch_cake: Make the dual modes fairer
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+CAKE host fairness does not work well with TCP flows in dual-srchost and
+dual-dsthost setup. The reason is that ACKs generated by TCP flows are
+classified as sparse flows, and affect flow isolation from other hosts. Fix
+this by calculating host_load based only on the bulk flows a host
+generates. In a hash collision the host_bulk_flow_count values must be
+decremented on the old hosts and incremented on the new ones *if* the queue
+is in the bulk set.
+
+Reported-by: Pete Heist <peteheist@gmail.com>
+Signed-off-by: George Amanakis <gamanakis@gmail.com>
+Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
+Signed-off-by: David S. Miller <davem@davemloft.net>
+Signed-off-by: Kevin Darbyshire-Bryant <ldir@darbyshire-bryant.me.uk>
+---
+ net/sched/sch_cake.c | 92 ++++++++++++++++++++++++++++++--------------
+ 1 file changed, 63 insertions(+), 29 deletions(-)
+
+--- a/net/sched/sch_cake.c
+++ b/net/sched/sch_cake.c
+@@ -138,8 +138,8 @@ struct cake_flow {
+ struct cake_host {
+ 	u32 srchost_tag;
+ 	u32 dsthost_tag;
+-	u16 srchost_refcnt;
+-	u16 dsthost_refcnt;
+	u16 srchost_bulk_flow_count;
+	u16 dsthost_bulk_flow_count;
+ };
+ 
+ struct cake_heap_entry {
+@@ -746,8 +746,10 @@ skip_hash:
+ 		 * queue, accept the collision, update the host tags.
+ 		 */
+ 		q->way_collisions++;
+-		q->hosts[q->flows[reduced_hash].srchost].srchost_refcnt--;
+-		q->hosts[q->flows[reduced_hash].dsthost].dsthost_refcnt--;
+		if (q->flows[outer_hash + k].set == CAKE_SET_BULK) {
+			q->hosts[q->flows[reduced_hash].srchost].srchost_bulk_flow_count--;
+			q->hosts[q->flows[reduced_hash].dsthost].dsthost_bulk_flow_count--;
+		}
+ 		allocate_src = cake_dsrc(flow_mode);
+ 		allocate_dst = cake_ddst(flow_mode);
+ found:
+@@ -767,13 +769,14 @@ found:
+ 			}
+ 			for (i = 0; i < CAKE_SET_WAYS;
+ 				i++, k = (k + 1) % CAKE_SET_WAYS) {
+-				if (!q->hosts[outer_hash + k].srchost_refcnt)
+				if (!q->hosts[outer_hash + k].srchost_bulk_flow_count)
+ 					break;
+ 			}
+ 			q->hosts[outer_hash + k].srchost_tag = srchost_hash;
+ found_src:
+ 			srchost_idx = outer_hash + k;
+-			q->hosts[srchost_idx].srchost_refcnt++;
+			if (q->flows[reduced_hash].set == CAKE_SET_BULK)
+				q->hosts[srchost_idx].srchost_bulk_flow_count++;
+ 			q->flows[reduced_hash].srchost = srchost_idx;
+ 		}
+ 
+@@ -789,13 +792,14 @@ found_src:
+ 			}
+ 			for (i = 0; i < CAKE_SET_WAYS;
+ 			     i++, k = (k + 1) % CAKE_SET_WAYS) {
+-				if (!q->hosts[outer_hash + k].dsthost_refcnt)
+				if (!q->hosts[outer_hash + k].dsthost_bulk_flow_count)
+ 					break;
+ 			}
+ 			q->hosts[outer_hash + k].dsthost_tag = dsthost_hash;
+ found_dst:
+ 			dsthost_idx = outer_hash + k;
+-			q->hosts[dsthost_idx].dsthost_refcnt++;
+			if (q->flows[reduced_hash].set == CAKE_SET_BULK)
+				q->hosts[dsthost_idx].dsthost_bulk_flow_count++;
+ 			q->flows[reduced_hash].dsthost = dsthost_idx;
+ 		}
+ 	}
+@@ -1793,20 +1797,30 @@ static s32 cake_enqueue(struct sk_buff *
+ 		b->sparse_flow_count++;
+ 
+ 		if (cake_dsrc(q->flow_mode))
+-			host_load = max(host_load, srchost->srchost_refcnt);
+			host_load = max(host_load, srchost->srchost_bulk_flow_count);
+ 
+ 		if (cake_ddst(q->flow_mode))
+-			host_load = max(host_load, dsthost->dsthost_refcnt);
+			host_load = max(host_load, dsthost->dsthost_bulk_flow_count);
+ 
+ 		flow->deficit = (b->flow_quantum *
+ 				 quantum_div[host_load]) >> 16;
+ 	} else if (flow->set == CAKE_SET_SPARSE_WAIT) {
+		struct cake_host *srchost = &b->hosts[flow->srchost];
+		struct cake_host *dsthost = &b->hosts[flow->dsthost];
+
+ 		/* this flow was empty, accounted as a sparse flow, but actually
+ 		 * in the bulk rotation.
+ 		 */
+ 		flow->set = CAKE_SET_BULK;
+ 		b->sparse_flow_count--;
+ 		b->bulk_flow_count++;
+
+		if (cake_dsrc(q->flow_mode))
+			srchost->srchost_bulk_flow_count++;
+
+		if (cake_ddst(q->flow_mode))
+			dsthost->dsthost_bulk_flow_count++;
+
+ 	}
+ 
+ 	if (q->buffer_used > q->buffer_max_used)
+@@ -1974,23 +1988,8 @@ retry:
+ 	dsthost = &b->hosts[flow->dsthost];
+ 	host_load = 1;
+ 
+-	if (cake_dsrc(q->flow_mode))
+-		host_load = max(host_load, srchost->srchost_refcnt);
+-
+-	if (cake_ddst(q->flow_mode))
+-		host_load = max(host_load, dsthost->dsthost_refcnt);
+-
+-	WARN_ON(host_load > CAKE_QUEUES);
+-
+ 	/* flow isolation (DRR++) */
+ 	if (flow->deficit <= 0) {
+-		/* The shifted prandom_u32() is a way to apply dithering to
+-		 * avoid accumulating roundoff errors
+-		 */
+-		flow->deficit += (b->flow_quantum * quantum_div[host_load] +
+-				  (prandom_u32() >> 16)) >> 16;
+-		list_move_tail(&flow->flowchain, &b->old_flows);
+-
+ 		/* Keep all flows with deficits out of the sparse and decaying
+ 		 * rotations.  No non-empty flow can go into the decaying
+ 		 * rotation, so they can't get deficits
+@@ -1999,6 +1998,13 @@ retry:
+ 			if (flow->head) {
+ 				b->sparse_flow_count--;
+ 				b->bulk_flow_count++;
+
+				if (cake_dsrc(q->flow_mode))
+					srchost->srchost_bulk_flow_count++;
+
+				if (cake_ddst(q->flow_mode))
+					dsthost->dsthost_bulk_flow_count++;
+
+ 				flow->set = CAKE_SET_BULK;
+ 			} else {
+ 				/* we've moved it to the bulk rotation for
+@@ -2008,6 +2014,22 @@ retry:
+ 				flow->set = CAKE_SET_SPARSE_WAIT;
+ 			}
+ 		}
+
+		if (cake_dsrc(q->flow_mode))
+			host_load = max(host_load, srchost->srchost_bulk_flow_count);
+
+		if (cake_ddst(q->flow_mode))
+			host_load = max(host_load, dsthost->dsthost_bulk_flow_count);
+
+		WARN_ON(host_load > CAKE_QUEUES);
+
+		/* The shifted prandom_u32() is a way to apply dithering to
+		 * avoid accumulating roundoff errors
+		 */
+		flow->deficit += (b->flow_quantum * quantum_div[host_load] +
+				  (prandom_u32() >> 16)) >> 16;
+		list_move_tail(&flow->flowchain, &b->old_flows);
+
+ 		goto retry;
+ 	}
+ 
+@@ -2028,6 +2050,13 @@ retry:
+ 					       &b->decaying_flows);
+ 				if (flow->set == CAKE_SET_BULK) {
+ 					b->bulk_flow_count--;
+
+					if (cake_dsrc(q->flow_mode))
+						srchost->srchost_bulk_flow_count--;
+
+					if (cake_ddst(q->flow_mode))
+						dsthost->dsthost_bulk_flow_count--;
+
+ 					b->decaying_flow_count++;
+ 				} else if (flow->set == CAKE_SET_SPARSE ||
+ 					   flow->set == CAKE_SET_SPARSE_WAIT) {
+@@ -2041,14 +2070,19 @@ retry:
+ 				if (flow->set == CAKE_SET_SPARSE ||
+ 				    flow->set == CAKE_SET_SPARSE_WAIT)
+ 					b->sparse_flow_count--;
+-				else if (flow->set == CAKE_SET_BULK)
+				else if (flow->set == CAKE_SET_BULK) {
+ 					b->bulk_flow_count--;
+-				else
+
+					if (cake_dsrc(q->flow_mode))
+						srchost->srchost_bulk_flow_count--;
+
+					if (cake_ddst(q->flow_mode))
+						dsthost->dsthost_bulk_flow_count--;
+
+				} else
+ 					b->decaying_flow_count--;
+ 
+ 				flow->set = CAKE_SET_NONE;
+-				srchost->srchost_refcnt--;
+-				dsthost->dsthost_refcnt--;
+ 			}
+ 			goto begin;
+ 		}
--- a/target/linux/generic/backport-4.19/391-v5.1-sch_cake-Permit-use-of-connmarks-as-tin-classifiers.patch
+++ b/target/linux/generic/backport-4.19/391-v5.1-sch_cake-Permit-use-of-connmarks-as-tin-classifiers.patch
@ -0,0 +1,118 @@
+From 0b5c7efdfc6e389ec6840579fe90bdb6f42b08dc Mon Sep 17 00:00:00 2001
+From: Kevin Darbyshire-Bryant <ldir@darbyshire-bryant.me.uk>
+Date: Fri, 1 Mar 2019 16:04:05 +0100
+Subject: [PATCH] sch_cake: Permit use of connmarks as tin classifiers
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+Add flag 'FWMARK' to enable use of firewall connmarks as tin selector.
+The connmark (skbuff->mark) needs to be in the range 1->tin_cnt ie.
+for diffserv3 the mark needs to be 1->3.
+
+Background
+
+Typically CAKE uses DSCP as the basis for tin selection.  DSCP values
+are relatively easily changed as part of the egress path, usually with
+iptables & the mangle table, ingress is more challenging.  CAKE is often
+used on the WAN interface of a residential gateway where passthrough of
+DSCP from the ISP is either missing or set to unhelpful values thus use
+of ingress DSCP values for tin selection isn't helpful in that
+environment.
+
+An approach to solving the ingress tin selection problem is to use
+CAKE's understanding of tc filters.  Naive tc filters could match on
+source/destination port numbers and force tin selection that way, but
+multiple filters don't scale particularly well as each filter must be
+traversed whether it matches or not. e.g. a simple example to map 3
+firewall marks to tins:
+
+MAJOR=$( tc qdisc show dev $DEV | head -1 | awk '{print $3}' )
+tc filter add dev $DEV parent $MAJOR protocol all handle 0x01 fw action skbedit priority ${MAJOR}1
+tc filter add dev $DEV parent $MAJOR protocol all handle 0x02 fw action skbedit priority ${MAJOR}2
+tc filter add dev $DEV parent $MAJOR protocol all handle 0x03 fw action skbedit priority ${MAJOR}3
+
+Another option is to use eBPF cls_act with tc filters e.g.
+
+MAJOR=$( tc qdisc show dev $DEV | head -1 | awk '{print $3}' )
+tc filter add dev $DEV parent $MAJOR bpf da obj my-bpf-fwmark-to-class.o
+
+This has the disadvantages of a) needing someone to write & maintain
+the bpf program, b) a bpf toolchain to compile it and c) needing to
+hardcode the major number in the bpf program so it matches the cake
+instance (or forcing the cake instance to a particular major number)
+since the major number cannot be passed to the bpf program via tc
+command line.
+
+As already hinted at by the previous examples, it would be helpful
+to associate tins with something that survives the Internet path and
+ideally allows tin selection on both egress and ingress.  Netfilter's
+conntrack permits setting an identifying mark on a connection which
+can also be restored to an ingress packet with tc action connmark e.g.
+
+tc filter add dev eth0 parent ffff: protocol all prio 10 u32 \
+	match u32 0 0 flowid 1:1 action connmark action mirred egress redirect dev ifb1
+
+Since tc's connmark action has restored any connmark into skb->mark,
+any of the previous solutions are based upon it and in one form or
+another copy that mark to the skb->priority field where again CAKE
+picks this up.
+
+This change cuts out at least one of the (less intuitive &
+non-scalable) middlemen and permit direct access to skb->mark.
+
+Signed-off-by: Kevin Darbyshire-Bryant <ldir@darbyshire-bryant.me.uk>
+Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
+Signed-off-by: David S. Miller <davem@davemloft.net>
+---
+ include/uapi/linux/pkt_sched.h |  1 +
+ net/sched/sch_cake.c           | 34 +++++++++++++++++++++++++++-------
+ 2 files changed, 28 insertions(+), 7 deletions(-)
+
+--- a/include/uapi/linux/pkt_sched.h
+++ b/include/uapi/linux/pkt_sched.h
+@@ -991,6 +991,7 @@ enum {
+ 	TCA_CAKE_INGRESS,
+ 	TCA_CAKE_ACK_FILTER,
+ 	TCA_CAKE_SPLIT_GSO,
+	TCA_CAKE_FWMARK,
+ 	__TCA_CAKE_MAX
+ };
+ #define TCA_CAKE_MAX	(__TCA_CAKE_MAX - 1)
+--- a/net/sched/sch_cake.c
+++ b/net/sched/sch_cake.c
+@@ -258,7 +258,8 @@ enum {
+ 	CAKE_FLAG_AUTORATE_INGRESS = BIT(1),
+ 	CAKE_FLAG_INGRESS	   = BIT(2),
+ 	CAKE_FLAG_WASH		   = BIT(3),
+-	CAKE_FLAG_SPLIT_GSO	   = BIT(4)
+	CAKE_FLAG_SPLIT_GSO	   = BIT(4),
+	CAKE_FLAG_FWMARK	   = BIT(5)
+ };
+ 
+ /* COBALT operates the Codel and BLUE algorithms in parallel, in order to
+@@ -2623,6 +2624,13 @@ static int cake_change(struct Qdisc *sch
+ 			q->rate_flags &= ~CAKE_FLAG_SPLIT_GSO;
+ 	}
+ 
+	if (tb[TCA_CAKE_FWMARK]) {
+		if (!!nla_get_u32(tb[TCA_CAKE_FWMARK]))
+			q->rate_flags |= CAKE_FLAG_FWMARK;
+		else
+			q->rate_flags &= ~CAKE_FLAG_FWMARK;
+	}
+
+ 	if (q->tins) {
+ 		sch_tree_lock(sch);
+ 		cake_reconfigure(sch);
+@@ -2782,6 +2790,10 @@ static int cake_dump(struct Qdisc *sch,
+ 			!!(q->rate_flags & CAKE_FLAG_SPLIT_GSO)))
+ 		goto nla_put_failure;
+ 
+	if (nla_put_u32(skb, TCA_CAKE_FWMARK,
+			!!(q->rate_flags & CAKE_FLAG_FWMARK)))
+		goto nla_put_failure;
+
+ 	return nla_nest_end(skb, opts);
+ 
+ nla_put_failure:
--- a/target/linux/generic/backport-4.19/392-v5.1-sch_cake-Interpret-fwmark-parameter-as-a-bitmask.patch
+++ b/target/linux/generic/backport-4.19/392-v5.1-sch_cake-Interpret-fwmark-parameter-as-a-bitmask.patch
@ -0,0 +1,102 @@
+From eab2fc822af38f31fd5f4e731b5d10b94904d919 Mon Sep 17 00:00:00 2001
+From: =?UTF-8?q?Toke=20H=C3=B8iland-J=C3=B8rgensen?= <toke@redhat.com>
+Date: Thu, 14 Mar 2019 23:08:22 +0100
+Subject: [PATCH] sch_cake: Interpret fwmark parameter as a bitmask
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+We initially interpreted the fwmark parameter as a flag that simply turned
+on the feature, using the whole skb->mark field as the index into the CAKE
+tin_order array. However, it is quite common for different applications to
+use different parts of the mask field for their own purposes, each using a
+different mask.
+
+Support this use of subsets of the mark by interpreting the TCA_CAKE_FWMARK
+parameter as a bitmask to apply to the fwmark field when reading it. The
+result will be right-shifted by the number of unset lower bits of the mask
+before looking up the tin.
+
+In the original commit message we also failed to credit Felix Resch with
+originally suggesting the fwmark feature back in 2017; so the Suggested-By
+in this commit covers the whole fwmark feature.
+
+Fixes: 0b5c7efdfc6e ("sch_cake: Permit use of connmarks as tin classifiers")
+Suggested-by: Felix Resch <fuller@beif.de>
+Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
+Signed-off-by: David S. Miller <davem@davemloft.net>
+Signed-off-by: Kevin Darbyshire-Bryant <ldir@darbyshire-bryant.me.uk>
+---
+ net/sched/sch_cake.c | 25 ++++++++++++-------------
+ 1 file changed, 12 insertions(+), 13 deletions(-)
+
+--- a/net/sched/sch_cake.c
+++ b/net/sched/sch_cake.c
+@@ -211,6 +211,9 @@ struct cake_sched_data {
+ 	u8		ack_filter;
+ 	u8		atm_mode;
+ 
+	u32		fwmark_mask;
+	u16		fwmark_shft;
+
+ 	/* time_next = time_this + ((len * rate_ns) >> rate_shft) */
+ 	u16		rate_shft;
+ 	ktime_t		time_next_packet;
+@@ -258,8 +261,7 @@ enum {
+ 	CAKE_FLAG_AUTORATE_INGRESS = BIT(1),
+ 	CAKE_FLAG_INGRESS	   = BIT(2),
+ 	CAKE_FLAG_WASH		   = BIT(3),
+-	CAKE_FLAG_SPLIT_GSO	   = BIT(4),
+-	CAKE_FLAG_FWMARK	   = BIT(5)
+	CAKE_FLAG_SPLIT_GSO	   = BIT(4)
+ };
+ 
+ /* COBALT operates the Codel and BLUE algorithms in parallel, in order to
+@@ -1554,7 +1556,7 @@ static struct cake_tin_data *cake_select
+ 					     struct sk_buff *skb)
+ {
+ 	struct cake_sched_data *q = qdisc_priv(sch);
+-	u32 tin;
+	u32 tin, mark;
+ 	u8 dscp;
+ 
+ 	/* Tin selection: Default to diffserv-based selection, allow overriding
+@@ -1562,6 +1564,7 @@ static struct cake_tin_data *cake_select
+ 	 */
+ 	dscp = cake_handle_diffserv(skb,
+ 				    q->rate_flags & CAKE_FLAG_WASH);
+	mark = (skb->mark & q->fwmark_mask) >> q->fwmark_shft;
+ 
+ 	if (q->tin_mode == CAKE_DIFFSERV_BESTEFFORT)
+ 		tin = 0;
+@@ -2178,6 +2181,7 @@ static const struct nla_policy cake_poli
+ 	[TCA_CAKE_MPU]		 = { .type = NLA_U32 },
+ 	[TCA_CAKE_INGRESS]	 = { .type = NLA_U32 },
+ 	[TCA_CAKE_ACK_FILTER]	 = { .type = NLA_U32 },
+	[TCA_CAKE_FWMARK]	 = { .type = NLA_U32 },
+ };
+ 
+ static void cake_set_rate(struct cake_tin_data *b, u64 rate, u32 mtu,
+@@ -2625,10 +2629,8 @@ static int cake_change(struct Qdisc *sch
+ 	}
+ 
+ 	if (tb[TCA_CAKE_FWMARK]) {
+-		if (!!nla_get_u32(tb[TCA_CAKE_FWMARK]))
+-			q->rate_flags |= CAKE_FLAG_FWMARK;
+-		else
+-			q->rate_flags &= ~CAKE_FLAG_FWMARK;
+		q->fwmark_mask = nla_get_u32(tb[TCA_CAKE_FWMARK]);
+		q->fwmark_shft = q->fwmark_mask ? __ffs(q->fwmark_mask) : 0;
+ 	}
+ 
+ 	if (q->tins) {
+@@ -2790,8 +2792,7 @@ static int cake_dump(struct Qdisc *sch,
+ 			!!(q->rate_flags & CAKE_FLAG_SPLIT_GSO)))
+ 		goto nla_put_failure;
+ 
+-	if (nla_put_u32(skb, TCA_CAKE_FWMARK,
+-			!!(q->rate_flags & CAKE_FLAG_FWMARK)))
+	if (nla_put_u32(skb, TCA_CAKE_FWMARK, q->fwmark_mask))
+ 		goto nla_put_failure;
+ 
+ 	return nla_nest_end(skb, opts);
--- a/target/linux/generic/backport-4.19/393-v5.5-sch_cake-drop-unused-variable-tin_quantum_prio.patch
+++ b/target/linux/generic/backport-4.19/393-v5.5-sch_cake-drop-unused-variable-tin_quantum_prio.patch
@ -0,0 +1,158 @@
+From d7e1738f0a0b0573ac93cf570ba3df9dee61b68e Mon Sep 17 00:00:00 2001
+From: Kevin 'ldir' Darbyshire-Bryant <ldir@darbyshire-bryant.me.uk>
+Date: Wed, 18 Dec 2019 14:05:13 +0000
+Subject: [PATCH 2/2] sch_cake: drop unused variable tin_quantum_prio
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+Turns out tin_quantum_prio isn't used anymore and is a leftover from a
+previous implementation of diffserv tins.  Since the variable isn't used
+in any calculations it can be eliminated.
+
+Drop variable and places where it was set.  Rename remaining variable
+and consolidate naming of intermediate variables that set it.
+
+Signed-off-by: Kevin Darbyshire-Bryant <ldir@darbyshire-bryant.me.uk>
+Acked-by: Toke Høiland-Jørgensen <toke@redhat.com>
+Signed-off-by: David S. Miller <davem@davemloft.net>
+---
+ net/sched/sch_cake.c | 59 ++++++++++++++------------------------------
+ 1 file changed, 18 insertions(+), 41 deletions(-)
+
+--- a/net/sched/sch_cake.c
+++ b/net/sched/sch_cake.c
+@@ -173,8 +173,7 @@ struct cake_tin_data {
+ 	u64	tin_rate_bps;
+ 	u16	tin_rate_shft;
+ 
+-	u16	tin_quantum_prio;
+-	u16	tin_quantum_band;
+	u16	tin_quantum;
+ 	s32	tin_deficit;
+ 	u32	tin_backlog;
+ 	u32	tin_dropped;
+@@ -1916,7 +1915,7 @@ begin:
+ 		while (b->tin_deficit < 0 ||
+ 		       !(b->sparse_flow_count + b->bulk_flow_count)) {
+ 			if (b->tin_deficit <= 0)
+-				b->tin_deficit += b->tin_quantum_band;
+				b->tin_deficit += b->tin_quantum;
+ 			if (b->sparse_flow_count + b->bulk_flow_count)
+ 				empty = false;
+ 
+@@ -2237,8 +2236,7 @@ static int cake_config_besteffort(struct
+ 
+ 	cake_set_rate(b, rate, mtu,
+ 		      us_to_ns(q->target), us_to_ns(q->interval));
+-	b->tin_quantum_band = 65535;
+-	b->tin_quantum_prio = 65535;
+	b->tin_quantum = 65535;
+ 
+ 	return 0;
+ }
+@@ -2249,8 +2247,7 @@ static int cake_config_precedence(struct
+ 	struct cake_sched_data *q = qdisc_priv(sch);
+ 	u32 mtu = psched_mtu(qdisc_dev(sch));
+ 	u64 rate = q->rate_bps;
+-	u32 quantum1 = 256;
+-	u32 quantum2 = 256;
+	u32 quantum = 256;
+ 	u32 i;
+ 
+ 	q->tin_cnt = 8;
+@@ -2263,18 +2260,14 @@ static int cake_config_precedence(struct
+ 		cake_set_rate(b, rate, mtu, us_to_ns(q->target),
+ 			      us_to_ns(q->interval));
+ 
+-		b->tin_quantum_prio = max_t(u16, 1U, quantum1);
+-		b->tin_quantum_band = max_t(u16, 1U, quantum2);
+		b->tin_quantum = max_t(u16, 1U, quantum);
+ 
+ 		/* calculate next class's parameters */
+ 		rate  *= 7;
+ 		rate >>= 3;
+ 
+-		quantum1  *= 3;
+-		quantum1 >>= 1;
+-
+-		quantum2  *= 7;
+-		quantum2 >>= 3;
+		quantum  *= 7;
+		quantum >>= 3;
+ 	}
+ 
+ 	return 0;
+@@ -2343,8 +2336,7 @@ static int cake_config_diffserv8(struct
+ 	struct cake_sched_data *q = qdisc_priv(sch);
+ 	u32 mtu = psched_mtu(qdisc_dev(sch));
+ 	u64 rate = q->rate_bps;
+-	u32 quantum1 = 256;
+-	u32 quantum2 = 256;
+	u32 quantum = 256;
+ 	u32 i;
+ 
+ 	q->tin_cnt = 8;
+@@ -2360,18 +2352,14 @@ static int cake_config_diffserv8(struct
+ 		cake_set_rate(b, rate, mtu, us_to_ns(q->target),
+ 			      us_to_ns(q->interval));
+ 
+-		b->tin_quantum_prio = max_t(u16, 1U, quantum1);
+-		b->tin_quantum_band = max_t(u16, 1U, quantum2);
+		b->tin_quantum = max_t(u16, 1U, quantum);
+ 
+ 		/* calculate next class's parameters */
+ 		rate  *= 7;
+ 		rate >>= 3;
+ 
+-		quantum1  *= 3;
+-		quantum1 >>= 1;
+-
+-		quantum2  *= 7;
+-		quantum2 >>= 3;
+		quantum  *= 7;
+		quantum >>= 3;
+ 	}
+ 
+ 	return 0;
+@@ -2410,17 +2398,11 @@ static int cake_config_diffserv4(struct
+ 	cake_set_rate(&q->tins[3], rate >> 2, mtu,
+ 		      us_to_ns(q->target), us_to_ns(q->interval));
+ 
+-	/* priority weights */
+-	q->tins[0].tin_quantum_prio = quantum;
+-	q->tins[1].tin_quantum_prio = quantum >> 4;
+-	q->tins[2].tin_quantum_prio = quantum << 2;
+-	q->tins[3].tin_quantum_prio = quantum << 4;
+-
+ 	/* bandwidth-sharing weights */
+-	q->tins[0].tin_quantum_band = quantum;
+-	q->tins[1].tin_quantum_band = quantum >> 4;
+-	q->tins[2].tin_quantum_band = quantum >> 1;
+-	q->tins[3].tin_quantum_band = quantum >> 2;
+	q->tins[0].tin_quantum = quantum;
+	q->tins[1].tin_quantum = quantum >> 4;
+	q->tins[2].tin_quantum = quantum >> 1;
+	q->tins[3].tin_quantum = quantum >> 2;
+ 
+ 	return 0;
+ }
+@@ -2451,15 +2433,10 @@ static int cake_config_diffserv3(struct
+ 	cake_set_rate(&q->tins[2], rate >> 2, mtu,
+ 		      us_to_ns(q->target), us_to_ns(q->interval));
+ 
+-	/* priority weights */
+-	q->tins[0].tin_quantum_prio = quantum;
+-	q->tins[1].tin_quantum_prio = quantum >> 4;
+-	q->tins[2].tin_quantum_prio = quantum << 4;
+-
+ 	/* bandwidth-sharing weights */
+-	q->tins[0].tin_quantum_band = quantum;
+-	q->tins[1].tin_quantum_band = quantum >> 4;
+-	q->tins[2].tin_quantum_band = quantum >> 2;
+	q->tins[0].tin_quantum = quantum;
+	q->tins[1].tin_quantum = quantum >> 4;
+	q->tins[2].tin_quantum = quantum >> 2;
+ 
+ 	return 0;
+ }
--- a/target/linux/generic/backport-4.19/394-v5.4-sch_cake-Add-missing-NLA-policy-entry-TCA_CAKE_SPLIT.patch
+++ b/target/linux/generic/backport-4.19/394-v5.4-sch_cake-Add-missing-NLA-policy-entry-TCA_CAKE_SPLIT.patch
@ -0,0 +1,30 @@
+From b3c424eb6a1a3c485de64619418a471dee6ce849 Mon Sep 17 00:00:00 2001
+From: Victorien Molle <victorien.molle@wifirst.fr>
+Date: Mon, 2 Dec 2019 15:11:38 +0100
+Subject: [PATCH] sch_cake: Add missing NLA policy entry TCA_CAKE_SPLIT_GSO
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+This field has never been checked since introduction in mainline kernel
+
+Signed-off-by: Victorien Molle <victorien.molle@wifirst.fr>
+Signed-off-by: Florent Fourcot <florent.fourcot@wifirst.fr>
+Fixes: 2db6dc2662ba "sch_cake: Make gso-splitting configurable from userspace"
+Acked-by: Toke Høiland-Jørgensen <toke@redhat.com>
+Signed-off-by: David S. Miller <davem@davemloft.net>
+Signed-off-by: Kevin Darbyshire-Bryant <ldir@darbyshire-bryant.me.uk>
+---
+ net/sched/sch_cake.c | 1 +
+ 1 file changed, 1 insertion(+)
+
+--- a/net/sched/sch_cake.c
+++ b/net/sched/sch_cake.c
+@@ -2180,6 +2180,7 @@ static const struct nla_policy cake_poli
+ 	[TCA_CAKE_MPU]		 = { .type = NLA_U32 },
+ 	[TCA_CAKE_INGRESS]	 = { .type = NLA_U32 },
+ 	[TCA_CAKE_ACK_FILTER]	 = { .type = NLA_U32 },
+	[TCA_CAKE_SPLIT_GSO]	 = { .type = NLA_U32 },
+ 	[TCA_CAKE_FWMARK]	 = { .type = NLA_U32 },
+ };
+ 
--- a/target/linux/generic/backport-4.19/395-v5.8-net-sch_cake-Take-advantage-of-skb-hash-where-appropriate.patch
+++ b/target/linux/generic/backport-4.19/395-v5.8-net-sch_cake-Take-advantage-of-skb-hash-where-appropriate.patch
@ -0,0 +1,170 @@
+From b0c19ed6088ab41dd2a727b60594b7297c15d6ce Mon Sep 17 00:00:00 2001
+From: =?UTF-8?q?Toke=20H=C3=B8iland-J=C3=B8rgensen?= <toke@redhat.com>
+Date: Fri, 29 May 2020 14:43:44 +0200
+Subject: [PATCH] sch_cake: Take advantage of skb->hash where appropriate
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+While the other fq-based qdiscs take advantage of skb->hash and doesn't
+recompute it if it is already set, sch_cake does not.
+
+This was a deliberate choice because sch_cake hashes various parts of the
+packet header to support its advanced flow isolation modes. However,
+foregoing the use of skb->hash entirely loses a few important benefits:
+
+- When skb->hash is set by hardware, a few CPU cycles can be saved by not
+  hashing again in software.
+
+- Tunnel encapsulations will generally preserve the value of skb->hash from
+  before the encapsulation, which allows flow-based qdiscs to distinguish
+  between flows even though the outer packet header no longer has flow
+  information.
+
+It turns out that we can preserve these desirable properties in many cases,
+while still supporting the advanced flow isolation properties of sch_cake.
+This patch does so by reusing the skb->hash value as the flow_hash part of
+the hashing procedure in cake_hash() only in the following conditions:
+
+- If the skb->hash is marked as covering the flow headers (skb->l4_hash is
+  set)
+
+AND
+
+- NAT header rewriting is either disabled, or did not change any values
+  used for hashing. The latter is important to match local-origin packets
+  such as those of a tunnel endpoint.
+
+The immediate motivation for fixing this was the recent patch to WireGuard
+to preserve the skb->hash on encapsulation. As such, this is also what I
+tested against; with this patch, added latency under load for competing
+flows drops from ~8 ms to sub-1ms on an RRUL test over a WireGuard tunnel
+going through a virtual link shaped to 1Gbps using sch_cake. This matches
+the results we saw with a similar setup using sch_fq_codel when testing the
+WireGuard patch.
+
+Fixes: 046f6fd5daef ("sched: Add Common Applications Kept Enhanced (cake) qdisc")
+Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
+Signed-off-by: David S. Miller <davem@davemloft.net>
+Signed-off-by: Kevin Darbyshire-Bryant <ldir@darbyshire-bryant.me.uk>
+---
+ net/sched/sch_cake.c | 65 ++++++++++++++++++++++++++++++++++----------
+ 1 file changed, 51 insertions(+), 14 deletions(-)
+
+--- a/net/sched/sch_cake.c
+++ b/net/sched/sch_cake.c
+@@ -584,26 +584,48 @@ static bool cobalt_should_drop(struct co
+ 	return drop;
+ }
+ 
+-static void cake_update_flowkeys(struct flow_keys *keys,
+static bool cake_update_flowkeys(struct flow_keys *keys,
+ 				 const struct sk_buff *skb)
+ {
+ #if IS_ENABLED(CONFIG_NF_CONNTRACK)
+ 	struct nf_conntrack_tuple tuple = {};
+-	bool rev = !skb->_nfct;
+	bool rev = !skb->_nfct, upd = false;
+	__be32 ip;
+ 
+ 	if (tc_skb_protocol(skb) != htons(ETH_P_IP))
+-		return;
+		return false;
+ 
+ 	if (!nf_ct_get_tuple_skb(&tuple, skb))
+-		return;
+		return false;
+ 
+-	keys->addrs.v4addrs.src = rev ? tuple.dst.u3.ip : tuple.src.u3.ip;
+-	keys->addrs.v4addrs.dst = rev ? tuple.src.u3.ip : tuple.dst.u3.ip;
+	ip = rev ? tuple.dst.u3.ip : tuple.src.u3.ip;
+	if (ip != keys->addrs.v4addrs.src) {
+		keys->addrs.v4addrs.src = ip;
+		upd = true;
+	}
+	ip = rev ? tuple.src.u3.ip : tuple.dst.u3.ip;
+	if (ip != keys->addrs.v4addrs.dst) {
+		keys->addrs.v4addrs.dst = ip;
+		upd = true;
+	}
+ 
+ 	if (keys->ports.ports) {
+-		keys->ports.src = rev ? tuple.dst.u.all : tuple.src.u.all;
+-		keys->ports.dst = rev ? tuple.src.u.all : tuple.dst.u.all;
+		__be16 port;
+
+		port = rev ? tuple.dst.u.all : tuple.src.u.all;
+		if (port != keys->ports.src) {
+			keys->ports.src = port;
+			upd = true;
+		}
+		port = rev ? tuple.src.u.all : tuple.dst.u.all;
+		if (port != keys->ports.dst) {
+			port = keys->ports.dst;
+			upd = true;
+		}
+ 	}
+	return upd;
+#else
+	return false;
+ #endif
+ }
+ 
+@@ -624,23 +646,36 @@ static bool cake_ddst(int flow_mode)
+ static u32 cake_hash(struct cake_tin_data *q, const struct sk_buff *skb,
+ 		     int flow_mode, u16 flow_override, u16 host_override)
+ {
+	bool hash_flows = (!flow_override && !!(flow_mode & CAKE_FLOW_FLOWS));
+	bool hash_hosts = (!host_override && !!(flow_mode & CAKE_FLOW_HOSTS));
+	bool nat_enabled = !!(flow_mode & CAKE_FLOW_NAT_FLAG);
+ 	u32 flow_hash = 0, srchost_hash = 0, dsthost_hash = 0;
+ 	u16 reduced_hash, srchost_idx, dsthost_idx;
+ 	struct flow_keys keys, host_keys;
+	bool use_skbhash = skb->l4_hash;
+ 
+ 	if (unlikely(flow_mode == CAKE_FLOW_NONE))
+ 		return 0;
+ 
+-	/* If both overrides are set we can skip packet dissection entirely */
+-	if ((flow_override || !(flow_mode & CAKE_FLOW_FLOWS)) &&
+-	    (host_override || !(flow_mode & CAKE_FLOW_HOSTS)))
+	/* If both overrides are set, or we can use the SKB hash and nat mode is
+	 * disabled, we can skip packet dissection entirely. If nat mode is
+	 * enabled there's another check below after doing the conntrack lookup.
+	 */
+	if ((!hash_flows || (use_skbhash && !nat_enabled)) && !hash_hosts)
+ 		goto skip_hash;
+ 
+ 	skb_flow_dissect_flow_keys(skb, &keys,
+ 				   FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL);
+ 
+-	if (flow_mode & CAKE_FLOW_NAT_FLAG)
+-		cake_update_flowkeys(&keys, skb);
+	/* Don't use the SKB hash if we change the lookup keys from conntrack */
+	if (nat_enabled && cake_update_flowkeys(&keys, skb))
+		use_skbhash = false;
+
+	/* If we can still use the SKB hash and don't need the host hash, we can
+	 * skip the rest of the hashing procedure
+	 */
+	if (use_skbhash && !hash_hosts)
+		goto skip_hash;
+ 
+ 	/* flow_hash_from_keys() sorts the addresses by value, so we have
+ 	 * to preserve their order in a separate data structure to treat
+@@ -679,12 +714,14 @@ static u32 cake_hash(struct cake_tin_dat
+ 	/* This *must* be after the above switch, since as a
+ 	 * side-effect it sorts the src and dst addresses.
+ 	 */
+-	if (flow_mode & CAKE_FLOW_FLOWS)
+	if (hash_flows && !use_skbhash)
+ 		flow_hash = flow_hash_from_keys(&keys);
+ 
+ skip_hash:
+ 	if (flow_override)
+ 		flow_hash = flow_override - 1;
+	else if (use_skbhash)
+		flow_hash = skb->hash;
+ 	if (host_override) {
+ 		dsthost_hash = host_override - 1;
+ 		srchost_hash = host_override - 1;
--- a/target/linux/generic/backport-4.19/396-5.8-sch_cake-don-t-try-to-reallocate-or-unshare-skb-unco.patch
+++ b/target/linux/generic/backport-4.19/396-5.8-sch_cake-don-t-try-to-reallocate-or-unshare-skb-unco.patch
@ -0,0 +1,96 @@
+From 9208d2863ac689a563b92f2161d8d1e7127d0add Mon Sep 17 00:00:00 2001
+From: Ilya Ponetayev <i.ponetaev@ndmsystems.com>
+Date: Thu, 25 Jun 2020 22:12:07 +0200
+Subject: [PATCH] sch_cake: don't try to reallocate or unshare skb
+ unconditionally
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+cake_handle_diffserv() tries to linearize mac and network header parts of
+skb and to make it writable unconditionally. In some cases it leads to full
+skb reallocation, which reduces throughput and increases CPU load. Some
+measurements of IPv4 forward + NAPT on MIPS router with 580 MHz single-core
+CPU was conducted. It appears that on kernel 4.9 skb_try_make_writable()
+reallocates skb, if skb was allocated in ethernet driver via so-called
+'build skb' method from page cache (it was discovered by strange increase
+of kmalloc-2048 slab at first).
+
+Obtain DSCP value via read-only skb_header_pointer() call, and leave
+linearization only for DSCP bleaching or ECN CE setting. And, as an
+additional optimisation, skip diffserv parsing entirely if it is not needed
+by the current configuration.
+
+Fixes: c87b4ecdbe8d ("sch_cake: Make sure we can write the IP header before changing DSCP bits")
+Signed-off-by: Ilya Ponetayev <i.ponetaev@ndmsystems.com>
+[ fix a few style issues, reflow commit message ]
+Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
+Signed-off-by: David S. Miller <davem@davemloft.net>
+Signed-off-by: Kevin Darbyshire-Bryant <ldir@darbyshire-bryant.me.uk>
+---
+ net/sched/sch_cake.c | 41 ++++++++++++++++++++++++++++++-----------
+ 1 file changed, 30 insertions(+), 11 deletions(-)
+
+--- a/net/sched/sch_cake.c
+++ b/net/sched/sch_cake.c
+@@ -1553,30 +1553,49 @@ static unsigned int cake_drop(struct Qdi
+ 
+ static u8 cake_handle_diffserv(struct sk_buff *skb, u16 wash)
+ {
+-	int wlen = skb_network_offset(skb);
+	const int offset = skb_network_offset(skb);
+	u16 *buf, buf_;
+ 	u8 dscp;
+ 
+ 	switch (tc_skb_protocol(skb)) {
+ 	case htons(ETH_P_IP):
+-		wlen += sizeof(struct iphdr);
+-		if (!pskb_may_pull(skb, wlen) ||
+-		    skb_try_make_writable(skb, wlen))
+		buf = skb_header_pointer(skb, offset, sizeof(buf_), &buf_);
+		if (unlikely(!buf))
+ 			return 0;
+ 
+-		dscp = ipv4_get_dsfield(ip_hdr(skb)) >> 2;
+-		if (wash && dscp)
+		/* ToS is in the second byte of iphdr */
+		dscp = ipv4_get_dsfield((struct iphdr *)buf) >> 2;
+
+		if (wash && dscp) {
+			const int wlen = offset + sizeof(struct iphdr);
+
+			if (!pskb_may_pull(skb, wlen) ||
+			    skb_try_make_writable(skb, wlen))
+				return 0;
+
+ 			ipv4_change_dsfield(ip_hdr(skb), INET_ECN_MASK, 0);
+		}
+
+ 		return dscp;
+ 
+ 	case htons(ETH_P_IPV6):
+-		wlen += sizeof(struct ipv6hdr);
+-		if (!pskb_may_pull(skb, wlen) ||
+-		    skb_try_make_writable(skb, wlen))
+		buf = skb_header_pointer(skb, offset, sizeof(buf_), &buf_);
+		if (unlikely(!buf))
+ 			return 0;
+ 
+-		dscp = ipv6_get_dsfield(ipv6_hdr(skb)) >> 2;
+-		if (wash && dscp)
+		/* Traffic class is in the first and second bytes of ipv6hdr */
+		dscp = ipv6_get_dsfield((struct ipv6hdr *)buf) >> 2;
+
+		if (wash && dscp) {
+			const int wlen = offset + sizeof(struct ipv6hdr);
+
+			if (!pskb_may_pull(skb, wlen) ||
+			    skb_try_make_writable(skb, wlen))
+				return 0;
+
+ 			ipv6_change_dsfield(ipv6_hdr(skb), INET_ECN_MASK, 0);
+		}
+
+ 		return dscp;
+ 
+ 	case htons(ETH_P_ARP):
--- a/target/linux/generic/backport-4.19/397-5.8-sch_cake-don-t-call-diffserv-parsing-code-when-it-is.patch
+++ b/target/linux/generic/backport-4.19/397-5.8-sch_cake-don-t-call-diffserv-parsing-code-when-it-is.patch
@ -0,0 +1,62 @@
+From 8c95eca0bb8c4bd2231a0d581f1ad0d50c90488c Mon Sep 17 00:00:00 2001
+From: =?UTF-8?q?Toke=20H=C3=B8iland-J=C3=B8rgensen?= <toke@redhat.com>
+Date: Thu, 25 Jun 2020 22:12:08 +0200
+Subject: [PATCH] sch_cake: don't call diffserv parsing code when it is not
+ needed
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+As a further optimisation of the diffserv parsing codepath, we can skip it
+entirely if CAKE is configured to neither use diffserv-based
+classification, nor to zero out the diffserv bits.
+
+Fixes: c87b4ecdbe8d ("sch_cake: Make sure we can write the IP header before changing DSCP bits")
+Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
+Signed-off-by: David S. Miller <davem@davemloft.net>
+Signed-off-by: Kevin Darbyshire-Bryant <ldir@darbyshire-bryant.me.uk>
+---
+ net/sched/sch_cake.c | 13 +++++++++----
+ 1 file changed, 9 insertions(+), 4 deletions(-)
+
+--- a/net/sched/sch_cake.c
+++ b/net/sched/sch_cake.c
+@@ -1551,7 +1551,7 @@ static unsigned int cake_drop(struct Qdi
+ 	return idx + (tin << 16);
+ }
+ 
+-static u8 cake_handle_diffserv(struct sk_buff *skb, u16 wash)
+static u8 cake_handle_diffserv(struct sk_buff *skb, bool wash)
+ {
+ 	const int offset = skb_network_offset(skb);
+ 	u16 *buf, buf_;
+@@ -1612,14 +1612,17 @@ static struct cake_tin_data *cake_select
+ {
+ 	struct cake_sched_data *q = qdisc_priv(sch);
+ 	u32 tin, mark;
+	bool wash;
+ 	u8 dscp;
+ 
+ 	/* Tin selection: Default to diffserv-based selection, allow overriding
+-	 * using firewall marks or skb->priority.
+	 * using firewall marks or skb->priority. Call DSCP parsing early if
+	 * wash is enabled, otherwise defer to below to skip unneeded parsing.
+ 	 */
+-	dscp = cake_handle_diffserv(skb,
+-				    q->rate_flags & CAKE_FLAG_WASH);
+ 	mark = (skb->mark & q->fwmark_mask) >> q->fwmark_shft;
+	wash = !!(q->rate_flags & CAKE_FLAG_WASH);
+	if (wash)
+		dscp = cake_handle_diffserv(skb, wash);
+ 
+ 	if (q->tin_mode == CAKE_DIFFSERV_BESTEFFORT)
+ 		tin = 0;
+@@ -1630,6 +1633,8 @@ static struct cake_tin_data *cake_select
+ 		tin = q->tin_order[TC_H_MIN(skb->priority) - 1];
+ 
+ 	else {
+		if (!wash)
+			dscp = cake_handle_diffserv(skb, wash);
+ 		tin = q->tin_index[dscp];
+ 
+ 		if (unlikely(tin >= q->tin_cnt))
--- a/target/linux/generic/backport-4.19/398-5.8-sch_cake-fix-a-few-style-nits.patch
+++ b/target/linux/generic/backport-4.19/398-5.8-sch_cake-fix-a-few-style-nits.patch
@ -0,0 +1,40 @@
+From 3f608f0c41360b11b04c763f348b712f651c8bac Mon Sep 17 00:00:00 2001
+From: =?UTF-8?q?Toke=20H=C3=B8iland-J=C3=B8rgensen?= <toke@redhat.com>
+Date: Thu, 25 Jun 2020 22:12:09 +0200
+Subject: [PATCH] sch_cake: fix a few style nits
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+I spotted a few nits when comparing the in-tree version of sch_cake with
+the out-of-tree one: A redundant error variable declaration shadowing an
+outer declaration, and an indentation alignment issue. Fix both of these.
+
+Fixes: 046f6fd5daef ("sched: Add Common Applications Kept Enhanced (cake) qdisc")
+Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
+Signed-off-by: David S. Miller <davem@davemloft.net>
+Signed-off-by: Kevin Darbyshire-Bryant <ldir@darbyshire-bryant.me.uk>
+---
+ net/sched/sch_cake.c | 4 ++--
+ 1 file changed, 2 insertions(+), 2 deletions(-)
+
+--- a/net/sched/sch_cake.c
+++ b/net/sched/sch_cake.c
+@@ -2713,7 +2713,7 @@ static int cake_init(struct Qdisc *sch,
+ 	qdisc_watchdog_init(&q->watchdog, sch);
+ 
+ 	if (opt) {
+-		int err = cake_change(sch, opt, extack);
+		err = cake_change(sch, opt, extack);
+ 
+ 		if (err)
+ 			return err;
+@@ -3030,7 +3030,7 @@ static int cake_dump_class_stats(struct
+ 			PUT_STAT_S32(BLUE_TIMER_US,
+ 				     ktime_to_us(
+ 					     ktime_sub(now,
+-						     flow->cvars.blue_timer)));
+						       flow->cvars.blue_timer)));
+ 		}
+ 		if (flow->cvars.dropping) {
+ 			PUT_STAT_S32(DROP_NEXT_US,
--- a/target/linux/generic/backport-4.19/399-5.9-sch_cake-add-RFC-8622-LE-PHB-support-to-CAKE-diffser.patch
+++ b/target/linux/generic/backport-4.19/399-5.9-sch_cake-add-RFC-8622-LE-PHB-support-to-CAKE-diffser.patch
@ -0,0 +1,57 @@
+From b8392808eb3fc28e523e28cb258c81ca246deb9b Mon Sep 17 00:00:00 2001
+From: Kevin Darbyshire-Bryant <ldir@darbyshire-bryant.me.uk>
+Date: Thu, 25 Jun 2020 22:18:00 +0200
+Subject: [PATCH] sch_cake: add RFC 8622 LE PHB support to CAKE diffserv
+ handling
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+Change tin mapping on diffserv3, 4 & 8 for LE PHB support, in essence
+making LE a member of the Bulk tin.
+
+Bulk has the least priority and minimum of 1/16th total bandwidth in the
+face of higher priority traffic.
+
+NB: Diffserv 3 & 4 swap tin 0 & 1 priorities from the default order as
+found in diffserv8, in case anyone is wondering why it looks a bit odd.
+
+Signed-off-by: Kevin Darbyshire-Bryant <ldir@darbyshire-bryant.me.uk>
+[ reword commit message slightly ]
+Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
+Signed-off-by: David S. Miller <davem@davemloft.net>
+---
+ net/sched/sch_cake.c | 8 ++++----
+ 1 file changed, 4 insertions(+), 4 deletions(-)
+
+--- a/net/sched/sch_cake.c
+++ b/net/sched/sch_cake.c
+@@ -312,8 +312,8 @@ static const u8 precedence[] = {
+ };
+ 
+ static const u8 diffserv8[] = {
+-	2, 5, 1, 2, 4, 2, 2, 2,
+-	0, 2, 1, 2, 1, 2, 1, 2,
+	2, 0, 1, 2, 4, 2, 2, 2,
+	1, 2, 1, 2, 1, 2, 1, 2,
+ 	5, 2, 4, 2, 4, 2, 4, 2,
+ 	3, 2, 3, 2, 3, 2, 3, 2,
+ 	6, 2, 3, 2, 3, 2, 3, 2,
+@@ -323,7 +323,7 @@ static const u8 diffserv8[] = {
+ };
+ 
+ static const u8 diffserv4[] = {
+-	0, 2, 0, 0, 2, 0, 0, 0,
+	0, 1, 0, 0, 2, 0, 0, 0,
+ 	1, 0, 0, 0, 0, 0, 0, 0,
+ 	2, 0, 2, 0, 2, 0, 2, 0,
+ 	2, 0, 2, 0, 2, 0, 2, 0,
+@@ -334,7 +334,7 @@ static const u8 diffserv4[] = {
+ };
+ 
+ static const u8 diffserv3[] = {
+-	0, 0, 0, 0, 2, 0, 0, 0,
+	0, 1, 0, 0, 2, 0, 0, 0,
+ 	1, 0, 0, 0, 0, 0, 0, 0,
+ 	0, 0, 0, 0, 0, 0, 0, 0,
+ 	0, 0, 0, 0, 0, 0, 0, 0,
--- a/target/linux/generic/hack-4.19/641-sch_cake-fix-IP-protocol-handling-in-the-presence-of.patch
+++ b/target/linux/generic/hack-4.19/641-sch_cake-fix-IP-protocol-handling-in-the-presence-of.patch
@ -0,0 +1,114 @@
+From a00590d570212c3c633bd463cef8ec7377cc7993 Mon Sep 17 00:00:00 2001
+From: Kevin Darbyshire-Bryant <ldir@darbyshire-bryant.me.uk>
+Date: Tue, 30 Jun 2020 12:07:44 +0100
+Subject: [PATCH] sch_cake: fix IP protocol handling in the presence of VLAN
+ tags
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+From: Ilya Ponetayev <i.ponetaev@ndmsystems.com>
+
+CAKE was using the return value of tc_skb_protocol() and expecting it to be
+the IP protocol type. This can fail in the presence of QinQ VLAN tags,
+making CAKE unable to handle ECN marking and diffserv parsing in this case.
+Fix this by implementing our own version of tc_skb_protocol(), which will
+use skb->protocol directly, but also parse and skip over any VLAN tags and
+return the inner protocol number instead.
+
+Also fix CE marking by implementing a version of INET_ECN_set_ce() that
+uses the same parsing routine.
+
+Fixes: ea82511518f4 ("sch_cake: Add NAT awareness to packet classifier")
+Fixes: b2100cc56fca ("sch_cake: Use tc_skb_protocol() helper for getting packet protocol")
+Fixes: 046f6fd5daef ("sched: Add Common Applications Kept Enhanced (cake) qdisc")
+Signed-off-by: Ilya Ponetayev <i.ponetaev@ndmsystems.com>
+[ squash original two patches, rewrite commit message ]
+Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
+Signed-off-by: Kevin Darbyshire-Bryant <ldir@darbyshire-bryant.me.uk>
+---
+ net/sched/sch_cake.c | 52 +++++++++++++++++++++++++++++++++++++++++---
+ 1 file changed, 49 insertions(+), 3 deletions(-)
+
+--- a/net/sched/sch_cake.c
+++ b/net/sched/sch_cake.c
+@@ -497,6 +497,52 @@ static bool cobalt_queue_empty(struct co
+ 	return down;
+ }
+ 
+static __be16 cake_skb_proto(const struct sk_buff *skb)
+{
+	unsigned int offset = skb_mac_offset(skb) + sizeof(struct ethhdr);
+	__be16 proto = skb->protocol;
+	struct vlan_hdr vhdr, *vh;
+
+	while (proto == htons(ETH_P_8021Q) || proto == htons(ETH_P_8021AD)) {
+		vh = skb_header_pointer(skb, offset, sizeof(vhdr), &vhdr);
+		if (!vh)
+			break;
+
+		proto = vh->h_vlan_encapsulated_proto;
+		offset += sizeof(vhdr);
+	}
+
+	return proto;
+}
+
+static int cake_set_ce(struct sk_buff *skb)
+{
+	int wlen = skb_network_offset(skb);
+
+	switch (cake_skb_proto(skb)) {
+	case htons(ETH_P_IP):
+		wlen += sizeof(struct iphdr);
+		if (!pskb_may_pull(skb, wlen) ||
+		    skb_try_make_writable(skb, wlen))
+			return 0;
+
+		return IP_ECN_set_ce(ip_hdr(skb));
+
+	case htons(ETH_P_IPV6):
+		wlen += sizeof(struct ipv6hdr);
+		if (!pskb_may_pull(skb, wlen) ||
+		    skb_try_make_writable(skb, wlen))
+			return 0;
+
+		return IP6_ECN_set_ce(skb, ipv6_hdr(skb));
+
+	default:
+		return 0;
+	}
+
+	return 0;
+}
+
+ /* Call this with a freshly dequeued packet for possible congestion marking.
+  * Returns true as an instruction to drop the packet, false for delivery.
+  */
+@@ -549,7 +595,7 @@ static bool cobalt_should_drop(struct co
+ 
+ 	if (next_due && vars->dropping) {
+ 		/* Use ECN mark if possible, otherwise drop */
+-		drop = !(vars->ecn_marked = INET_ECN_set_ce(skb));
+		drop = !(vars->ecn_marked = cake_set_ce(skb));
+ 
+ 		vars->count++;
+ 		if (!vars->count)
+@@ -592,7 +638,7 @@ static bool cake_update_flowkeys(struct
+ 	bool rev = !skb->_nfct, upd = false;
+ 	__be32 ip;
+ 
+-	if (tc_skb_protocol(skb) != htons(ETH_P_IP))
+	if (cake_skb_proto(skb) != htons(ETH_P_IP))
+ 		return false;
+ 
+ 	if (!nf_ct_get_tuple_skb(&tuple, skb))
+@@ -1557,7 +1603,7 @@ static u8 cake_handle_diffserv(struct sk
+ 	u16 *buf, buf_;
+ 	u8 dscp;
+ 
+-	switch (tc_skb_protocol(skb)) {
+	switch (cake_skb_proto(skb)) {
+ 	case htons(ETH_P_IP):
+ 		buf = skb_header_pointer(skb, offset, sizeof(buf_), &buf_);
+ 		if (unlikely(!buf))