Merge branch 'sched-introduce-chain-templates-support-with-offloading-to-mlxsw'

Jiri Pirko says:

====================
sched: introduce chain templates support with offloading to mlxsw

For the TC clsact offload these days, some of HW drivers need
to hold a magic ball. The reason is, with the first inserted rule inside
HW they need to guess what fields will be used for the matching. If
later on this guess proves to be wrong and user adds a filter with a
different field to match, there's a problem. Mlxsw resolves it now with
couple of patterns. Those try to cover as many match fields as possible.
This aproach is far from optimal, both performance-wise and scale-wise.
Also, there is a combination of filters that in certain order won't
succeed.

Most of the time, when user inserts filters in chain, he knows right away
how the filters are going to look like - what type and option will they
have. For example, he knows that he will only insert filters of type
flower matching destination IP address. He can specify a template that
would cover all the filters in the chain.

This patchset is providing the possibility to user to provide such
template to kernel and propagate it all the way down to device
drivers.

See the examples below.

Create dummy device with clsact first:

There is no chain present by by default:

Add chain number 11 by explicit command:
chain parent ffff: chain 11

Add filter to chain number 12 which does not exist. That will create
implicit chain 12:
chain parent ffff: chain 11
chain parent ffff: chain 12

Delete both chains:

Add a chain with template of type flower allowing to insert rules matching
on last 2 bytes of destination mac address:

The chain with template is now showed in the list:
chain parent ffff: flower chain 0
  dst_mac 00:00:00:00:00:00/00:00:00:00:ff:ff
  eth_type ipv4

Add another chain (number 22) with template:
chain parent ffff: flower chain 0
  dst_mac 00:00:00:00:00:00/00:00:00:00:ff:ff
  eth_type ipv4
chain parent ffff: flower chain 22
  eth_type ipv4
  dst_ip 0.0.0.0/16

Add a filter that fits the template:

Addition of filters that does not fit the template would fail:
Error: cls_flower: Mask does not fit the template.
We have an error talking to the kernel, -1
Error: cls_flower: Mask does not fit the template.
We have an error talking to the kernel, -1

Additions of filters to chain 22:
Error: cls_flower: Mask does not fit the template.
We have an error talking to the kernel, -1
Error: cls_flower: Mask does not fit the template.
We have an error talking to the kernel, -1

---
v3->v4:
- patch 2:
  - new patch
- patch 3:
  - new patch, derived from the previous v3 chaintemplate obj patch
- patch 4:
  - only templates part as chains creation/deletion is now a separate patch
  - don't pass template priv as arg of "change" op
- patch 6:
  - rebased on top of flower cvlan patch and ip tos/ttl patch
- patch 7:
  - templave priv is no longer passed as an arg to "change" op
- patch 11:
  - split from the originally single patch
- patch 12:
  - split from the originally single patch
v2->v3:
- patch 7:
  - rebase on top of the reoffload patchset
- patch 8:
  - rebase on top of the reoffload patchset
v1->v2:
- patch 8:
  - remove leftover extack arg in fl_hw_create_tmplt()
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 26 insertions, 1 deletions

diff --git a/include/net/pkt_cls.h b/include/net/pkt_cls.h
index 4f405ca8346f..a3101582f642 100644
--- a/include/net/pkt_cls.h
+++ b/include/net/pkt_cls.h
@@ -721,6 +721,8 @@ enum tc_fl_command {
 	TC_CLSFLOWER_REPLACE,
 	TC_CLSFLOWER_DESTROY,
 	TC_CLSFLOWER_STATS,
+	TC_CLSFLOWER_TMPLT_CREATE,
+	TC_CLSFLOWER_TMPLT_DESTROY,
 };
 
 struct tc_cls_flower_offload {
diff --git a/include/net/sch_generic.h b/include/net/sch_generic.h
index 7432100027b7..085c509c8674 100644
--- a/include/net/sch_generic.h
+++ b/include/net/sch_generic.h
@@ -238,6 +238,8 @@ struct tcf_result {
 	};
 };
 
+struct tcf_chain;
+
 struct tcf_proto_ops {
 	struct list_head	head;
 	char			kind[IFNAMSIZ];
@@ -263,10 +265,18 @@ struct tcf_proto_ops {
 					     tc_setup_cb_t *cb, void *cb_priv,
 					     struct netlink_ext_ack *extack);
 	void			(*bind_class)(void *, u32, unsigned long);
+	void *			(*tmplt_create)(struct net *net,
+						struct tcf_chain *chain,
+						struct nlattr **tca,
+						struct netlink_ext_ack *extack);
+	void			(*tmplt_destroy)(void *tmplt_priv);
 
 	/* rtnetlink specific */
 	int			(*dump)(struct net*, struct tcf_proto*, void *,
 					struct sk_buff *skb, struct tcmsg*);
+	int			(*tmplt_dump)(struct sk_buff *skb,
+					      struct net *net,
+					      void *tmplt_priv);
 
 	struct module		*owner;
 };
@@ -300,11 +310,13 @@ typedef void tcf_chain_head_change_t(struct tcf_proto *tp_head, void *priv);
 
 struct tcf_chain {
 	struct tcf_proto __rcu *filter_chain;
-	struct list_head filter_chain_list;
 	struct list_head list;
 	struct tcf_block *block;
 	u32 index; /* chain index */
 	unsigned int refcnt;
+	bool explicitly_created;
+	const struct tcf_proto_ops *tmplt_ops;
+	void *tmplt_priv;
 };
 
 struct tcf_block {
@@ -318,6 +330,10 @@ struct tcf_block {
 	bool keep_dst;
 	unsigned int offloadcnt; /* Number of oddloaded filters */
 	unsigned int nooffloaddevcnt; /* Number of devs unable to do offload */
+	struct {
+		struct tcf_chain *chain;
+		struct list_head filter_chain_list;
+	} chain0;
 };
 
 static inline void tcf_block_offload_inc(struct tcf_block *block, u32 *flags)
diff --git a/include/uapi/linux/rtnetlink.h b/include/uapi/linux/rtnetlink.h
index 7d8502313c99..46399367627f 100644
--- a/include/uapi/linux/rtnetlink.h
+++ b/include/uapi/linux/rtnetlink.h
@@ -150,6 +150,13 @@ enum {
 	RTM_NEWCACHEREPORT = 96,
 #define RTM_NEWCACHEREPORT RTM_NEWCACHEREPORT
 
+	RTM_NEWCHAIN = 100,
+#define RTM_NEWCHAIN RTM_NEWCHAIN
+	RTM_DELCHAIN,
+#define RTM_DELCHAIN RTM_DELCHAIN
+	RTM_GETCHAIN,
+#define RTM_GETCHAIN RTM_GETCHAIN
+
 	__RTM_MAX,
 #define RTM_MAX		(((__RTM_MAX + 3) & ~3) - 1)
 };