Date:	Tue, 1 Mar 2016 15:47:19 +0100
From:	Jiri Pirko <jiri@...nulli.us>
To:	Amir Vadai <amir@...ai.me>
Cc:	"David S. Miller" <davem@...emloft.net>, netdev@...r.kernel.org,
	Or Gerlitz <ogerlitz@...lanox.com>,
	John Fastabend <john.r.fastabend@...el.com>,
	Saeed Mahameed <saeedm@...lanox.com>,
	Hadar Har-Zion <hadarh@...lanox.com>,
	Jiri Pirko <jiri@...lanox.com>
Subject: Re: [PATCH net-next 1/8] net/flower: Introduce hardware offload
 support

Tue, Mar 01, 2016 at 03:24:43PM CET, amir@...ai.me wrote:
>This patch is based on a patch made by John Fastabend.
>It adds support for offloading cls_flower.
>A filter that is offloaded successfuly by hardware, will not be added to
>the hashtable and won't be processed by software.

That is wrong. User should explitly specify to not include rule into sw
by SKIP_KERNEL flag (does not exist now, with John's recent patch we'll
have only SKIP_HW). Please add that in this patchset.


>
>Suggested-by: John Fastabend <john.r.fastabend@...el.com>
>Signed-off-by: Amir Vadai <amir@...ai.me>
>---
> include/linux/netdevice.h    |  2 ++
> include/net/pkt_cls.h        | 14 +++++++++
> include/uapi/linux/pkt_cls.h |  2 ++
> net/sched/cls_flower.c       | 75 +++++++++++++++++++++++++++++++++++++++++---
> 4 files changed, 88 insertions(+), 5 deletions(-)
>
>diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
>index e52077f..0fd329a 100644
>--- a/include/linux/netdevice.h
>+++ b/include/linux/netdevice.h
>@@ -785,6 +785,7 @@ typedef u16 (*select_queue_fallback_t)(struct net_device *dev,
> enum {
> 	TC_SETUP_MQPRIO,
> 	TC_SETUP_CLSU32,
>+	TC_SETUP_CLSFLOWER,
> };
> 
> struct tc_cls_u32_offload;
>@@ -794,6 +795,7 @@ struct tc_to_netdev {
> 	union {
> 		u8 tc;
> 		struct tc_cls_u32_offload *cls_u32;
>+		struct tc_cls_flower_offload *cls_flower;
> 	};
> };
> 
>diff --git a/include/net/pkt_cls.h b/include/net/pkt_cls.h
>index bea14ee..beb2ee1 100644
>--- a/include/net/pkt_cls.h
>+++ b/include/net/pkt_cls.h
>@@ -409,4 +409,18 @@ static inline bool tc_should_offload(struct net_device *dev, u32 flags)
> 	return true;
> }
> 
>+enum {
>+	TC_CLSFLOWER_REPLACE,
>+	TC_CLSFLOWER_DESTROY,
>+};
>+
>+struct tc_cls_flower_offload {
>+	int command;
>+	u64 cookie;
>+	struct flow_dissector *dissector;
>+	struct fl_flow_key *mask;
>+	struct fl_flow_key *key;
>+	struct tcf_exts *exts;
>+};
>+
> #endif
>diff --git a/include/uapi/linux/pkt_cls.h b/include/uapi/linux/pkt_cls.h
>index 9874f568..c43c5f7 100644
>--- a/include/uapi/linux/pkt_cls.h
>+++ b/include/uapi/linux/pkt_cls.h
>@@ -417,6 +417,8 @@ enum {
> 	TCA_FLOWER_KEY_TCP_DST,		/* be16 */
> 	TCA_FLOWER_KEY_UDP_SRC,		/* be16 */
> 	TCA_FLOWER_KEY_UDP_DST,		/* be16 */
>+
>+	TCA_FLOWER_FLAGS,
> 	__TCA_FLOWER_MAX,
> };
> 
>diff --git a/net/sched/cls_flower.c b/net/sched/cls_flower.c
>index 95b0212..e599bea 100644
>--- a/net/sched/cls_flower.c
>+++ b/net/sched/cls_flower.c
>@@ -165,6 +165,53 @@ static void fl_destroy_filter(struct rcu_head *head)
> 	kfree(f);
> }
> 
>+static int fl_hw_destroy_filter(struct tcf_proto *tp, u64 cookie)
>+{
>+	struct net_device *dev = tp->q->dev_queue->dev;
>+	struct tc_cls_flower_offload offload = {0};
>+	struct tc_to_netdev tc;
>+
>+	if (!tc_should_offload(dev, 0))
>+		return -ENOTSUPP;
>+
>+	offload.command = TC_CLSFLOWER_DESTROY;
>+	offload.cookie = cookie;
>+
>+	tc.type = TC_SETUP_CLSFLOWER;
>+	tc.cls_flower = &offload;
>+
>+	return dev->netdev_ops->ndo_setup_tc(dev, tp->q->handle, tp->protocol,
>+					     &tc);
>+}
>+
>+static int fl_hw_replace_filter(struct tcf_proto *tp,
>+				struct flow_dissector *dissector,
>+				struct fl_flow_key *mask,
>+				struct fl_flow_key *key,
>+				struct tcf_exts *actions,
>+				u64 cookie, u32 flags)
>+{
>+	struct net_device *dev = tp->q->dev_queue->dev;
>+	struct tc_cls_flower_offload offload = {0};
>+	struct tc_to_netdev tc;
>+
>+	if (!tc_should_offload(dev, flags))
>+		return -ENOTSUPP;
>+
>+	offload.command = TC_CLSFLOWER_REPLACE;
>+	offload.cookie = cookie;
>+	offload.dissector = dissector;
>+	offload.mask = mask;
>+	offload.key = key;
>+	offload.exts = actions;
>+
>+	tc.type = TC_SETUP_CLSFLOWER;
>+	tc.cls_flower = &offload;
>+
>+	return dev->netdev_ops->ndo_setup_tc(dev, tp->q->handle, tp->protocol,
>+					     &tc);
>+}
>+
> static bool fl_destroy(struct tcf_proto *tp, bool force)
> {
> 	struct cls_fl_head *head = rtnl_dereference(tp->root);
>@@ -174,6 +221,7 @@ static bool fl_destroy(struct tcf_proto *tp, bool force)
> 		return false;
> 
> 	list_for_each_entry_safe(f, next, &head->filters, list) {
>+		fl_hw_destroy_filter(tp, (u64)f);
> 		list_del_rcu(&f->list);
> 		call_rcu(&f->rcu, fl_destroy_filter);
> 	}
>@@ -459,6 +507,7 @@ static int fl_change(struct net *net, struct sk_buff *in_skb,
> 	struct cls_fl_filter *fnew;
> 	struct nlattr *tb[TCA_FLOWER_MAX + 1];
> 	struct fl_flow_mask mask = {};
>+	u32 flags = 0;
> 	int err;
> 
> 	if (!tca[TCA_OPTIONS])
>@@ -494,13 +543,28 @@ static int fl_change(struct net *net, struct sk_buff *in_skb,
> 	if (err)
> 		goto errout;
> 
>-	err = rhashtable_insert_fast(&head->ht, &fnew->ht_node,
>-				     head->ht_params);
>-	if (err)
>-		goto errout;
>-	if (fold)
>+	if (tb[TCA_FLOWER_FLAGS])
>+		flags = nla_get_u32(tb[TCA_FLOWER_FLAGS]);
>+
>+	err = fl_hw_replace_filter(tp,
>+				   &head->dissector,
>+				   &mask.key,
>+				   &fnew->key,
>+				   &fnew->exts,
>+				   (u64)fnew,
>+				   flags);
>+	if (err) {
>+		err = rhashtable_insert_fast(&head->ht, &fnew->ht_node,
>+					     head->ht_params);
>+		if (err)
>+			goto errout;
>+	}
>+
>+	if (fold) {
> 		rhashtable_remove_fast(&head->ht, &fold->ht_node,
> 				       head->ht_params);
>+		fl_hw_destroy_filter(tp, (u64)fold);
>+	}
> 
> 	*arg = (unsigned long) fnew;
> 
>@@ -527,6 +591,7 @@ static int fl_delete(struct tcf_proto *tp, unsigned long arg)
> 	rhashtable_remove_fast(&head->ht, &f->ht_node,
> 			       head->ht_params);
> 	list_del_rcu(&f->list);
>+	fl_hw_destroy_filter(tp, (u64)f);
> 	tcf_unbind_filter(tp, &f->res);
> 	call_rcu(&f->rcu, fl_destroy_filter);
> 	return 0;
>-- 
>2.7.0
>

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