Merge branch 'net-sched-allow-qdiscs-to-share-filter-block-instances'

Jiri Pirko says:

====================
net: sched: allow qdiscs to share filter block instances

Currently the filters added to qdiscs are independent. So for example if you
have 2 netdevices and you create ingress qdisc on both and you want to add
identical filter rules both, you need to add them twice. This patchset
makes this easier and mainly saves resources allowing to share all filters
within a qdisc - I call it a "filter block". Also this helps to save
resources when we do offload to hw for example to expensive TCAM.

So back to the example. First, we create 2 qdiscs. Both will share
block number 22. "22" is just an identification:
$ tc qdisc add dev ens7 ingress_block 22 ingress
                        ^^^^^^^^^^^^^^^^
$ tc qdisc add dev ens8 ingress_block 22 ingress
                        ^^^^^^^^^^^^^^^^

If we don't specify "block" command line option, no shared block would
be created:
$ tc qdisc add dev ens9 ingress

Now if we list the qdiscs, we will see the block index in the output:

$ tc qdisc
qdisc ingress ffff: dev ens7 parent ffff:fff1 ingress_block 22
qdisc ingress ffff: dev ens8 parent ffff:fff1 ingress_block 22
qdisc ingress ffff: dev ens9 parent ffff:fff1

To make is more visual, the situation looks like this:

   ens7 ingress qdisc                 ens7 ingress qdisc
          |                                  |
          |                                  |
          +---------->  block 22  <----------+

Unlimited number of qdiscs may share the same block.

Note that this patchset introduces block sharing support also for clsact
qdisc:
$ tc qdisc add dev ens10 ingress_block 23 egress_block 24 clsact
$ tc qdisc show dev ens10
qdisc clsact ffff: dev ens10 parent ffff:fff1 ingress_block 23 egress_block 24

We can add filter using the block index:

$ tc filter add block 22 protocol ip pref 25 flower dst_ip 192.168.0.0/16 action drop

Note we cannot use the qdisc for filter manipulations of shared blocks:

$ tc filter add dev ens8 ingress protocol ip pref 1 flower dst_ip 192.168.100.2 action drop
Error: This filter block is shared. Please use the block index to manipulate the filters.

We will see the same output if we list filters for ingress qdisc of
ens7 and ens8, also for the block 22:

$ tc filter show block 22
filter block 22 protocol ip pref 25 flower chain 0
filter block 22 protocol ip pref 25 flower chain 0 handle 0x1
...

$ tc filter show dev ens7 ingress
filter block 22 protocol ip pref 25 flower chain 0
filter block 22 protocol ip pref 25 flower chain 0 handle 0x1
...

$ tc filter show dev ens8 ingress
filter block 22 protocol ip pref 25 flower chain 0
filter block 22 protocol ip pref 25 flower chain 0 handle 0x1
...

---
v10->v11:
- patch 2:
 - fixed error path when register_pernet_subsys fails pointed out by Cong
- patch 9:
 - rebased on top of the current net-next

v9->v10:
- patch 7:
 - fixed ifindex magic in the patch description
- userspace patches:
 - added manpages and patch descriptions

v8->v9:
- patch "net: sched: add rt netlink message type for block get" was
  removed, userspace check filter existence using qdisc dump

v7->v8:
- patch 7:
 - added comment to ifindex block magic
- patch 9:
 - new patch
- patch 10:
 - base this on the patch that introduces qdisc-generic block index
   attributes parsing/dumping
- patch 13:
 - rebased on top of current net-next

v6->v7:
- patch 1:
 - unsquashed shared block patch that was previously squashed by mistake
 - fixed error path in block create - freeing chain 0
- patch 2:
 - new patch - splitted from the previous one as it got accidentaly
   squashed in the rebasing process in the past
 - converted to idr extended
 - removed auto-generating of block indexes. Callers have to explicily
   tell that the block is shared by passing non-zero block index
 - fixed error path in block get ext - freeing chain 0
- patch 7:
 - changed extack message for block index handle as suggested by DaveA
 - added extack message when block index does not exist
 - the block ifindex magic is in define and change to 0xffffffff
   as suggested by Jamal
- patch 8:
 - new patch implementing RTM_GETBLOCK in order to query if the block
   with some index exists
- patch 9:
 - adjust to the core changes and check block index attributes for being 0

v5->v6:
- added patch 6 that introduces block handle

v4->v5:
- patch 5:
 - add tracking of binding of devs that are unable to offload and check
   that before block cbs call.

v3->v4:
- patch 1:
 - rebased on top of the current net-next
 - added some extack strings
- patch 3:
 - rebased on top of the current net-next
- patch 5:
 - propagate netdev_ops->ndo_setup_tc error up to tcf_block_offload_bind
   caller
- patch 7:
 - rebased on top of the current net-next

v2->v3:
- removed original patch 1, removing tp->q cls_bpf dependency. Fixed by
  Jakub in the meantime.
- patch 1:
 - rebased on top of the current net-next
- patch 5:
 - new patch
- patch 8:
 - removed "p_" prefix from block index function args
- patch 10:
 - add tc offload feature handling
====================

Acked-by: David Ahern <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

drivers/net/ethernet/mellanox/mlxsw/spectrum.c

@@ -1747,72 +1747,186 @@ static int mlxsw_sp_setup_tc_cls_matchall(struct mlxsw_sp_port *mlxsw_sp_port,
 }
 
 static int
-mlxsw_sp_setup_tc_cls_flower(struct mlxsw_sp_port *mlxsw_sp_port,
-			     struct tc_cls_flower_offload *f,
-			     bool ingress)
+mlxsw_sp_setup_tc_cls_flower(struct mlxsw_sp_acl_block *acl_block,
+			     struct tc_cls_flower_offload *f)
 {
+	struct mlxsw_sp *mlxsw_sp = mlxsw_sp_acl_block_mlxsw_sp(acl_block);
+
 	switch (f->command) {
 	case TC_CLSFLOWER_REPLACE:
-		return mlxsw_sp_flower_replace(mlxsw_sp_port, ingress, f);
+		return mlxsw_sp_flower_replace(mlxsw_sp, acl_block, f);
 	case TC_CLSFLOWER_DESTROY:
-		mlxsw_sp_flower_destroy(mlxsw_sp_port, ingress, f);
+		mlxsw_sp_flower_destroy(mlxsw_sp, acl_block, f);
 		return 0;
 	case TC_CLSFLOWER_STATS:
-		return mlxsw_sp_flower_stats(mlxsw_sp_port, ingress, f);
+		return mlxsw_sp_flower_stats(mlxsw_sp, acl_block, f);
 	default:
 		return -EOPNOTSUPP;
 	}
 }
 
-static int mlxsw_sp_setup_tc_block_cb(enum tc_setup_type type, void *type_data,
-				      void *cb_priv, bool ingress)
+static int mlxsw_sp_setup_tc_block_cb_matchall(enum tc_setup_type type,
+					       void *type_data,
+					       void *cb_priv, bool ingress)
 {
 	struct mlxsw_sp_port *mlxsw_sp_port = cb_priv;
 
-	if (!tc_can_offload(mlxsw_sp_port->dev))
-		return -EOPNOTSUPP;
-
 	switch (type) {
 	case TC_SETUP_CLSMATCHALL:
+		if (!tc_can_offload(mlxsw_sp_port->dev))
+			return -EOPNOTSUPP;
+
 		return mlxsw_sp_setup_tc_cls_matchall(mlxsw_sp_port, type_data,
 						      ingress);
 	case TC_SETUP_CLSFLOWER:
-		return mlxsw_sp_setup_tc_cls_flower(mlxsw_sp_port, type_data,
-						    ingress);
+		return 0;
 	default:
 		return -EOPNOTSUPP;
 	}
 }
 
-static int mlxsw_sp_setup_tc_block_cb_ig(enum tc_setup_type type,
-					 void *type_data, void *cb_priv)
+static int mlxsw_sp_setup_tc_block_cb_matchall_ig(enum tc_setup_type type,
+						  void *type_data,
+						  void *cb_priv)
 {
-	return mlxsw_sp_setup_tc_block_cb(type, type_data, cb_priv, true);
+	return mlxsw_sp_setup_tc_block_cb_matchall(type, type_data,
+						   cb_priv, true);
 }
 
-static int mlxsw_sp_setup_tc_block_cb_eg(enum tc_setup_type type,
-					 void *type_data, void *cb_priv)
+static int mlxsw_sp_setup_tc_block_cb_matchall_eg(enum tc_setup_type type,
+						  void *type_data,
+						  void *cb_priv)
 {
-	return mlxsw_sp_setup_tc_block_cb(type, type_data, cb_priv, false);
+	return mlxsw_sp_setup_tc_block_cb_matchall(type, type_data,
+						   cb_priv, false);
+}
+
+static int mlxsw_sp_setup_tc_block_cb_flower(enum tc_setup_type type,
+					     void *type_data, void *cb_priv)
+{
+	struct mlxsw_sp_acl_block *acl_block = cb_priv;
+
+	switch (type) {
+	case TC_SETUP_CLSMATCHALL:
+		return 0;
+	case TC_SETUP_CLSFLOWER:
+		if (mlxsw_sp_acl_block_disabled(acl_block))
+			return -EOPNOTSUPP;
+
+		return mlxsw_sp_setup_tc_cls_flower(acl_block, type_data);
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static int
+mlxsw_sp_setup_tc_block_flower_bind(struct mlxsw_sp_port *mlxsw_sp_port,
+				    struct tcf_block *block, bool ingress)
+{
+	struct mlxsw_sp *mlxsw_sp = mlxsw_sp_port->mlxsw_sp;
+	struct mlxsw_sp_acl_block *acl_block;
+	struct tcf_block_cb *block_cb;
+	int err;
+
+	block_cb = tcf_block_cb_lookup(block, mlxsw_sp_setup_tc_block_cb_flower,
+				       mlxsw_sp);
+	if (!block_cb) {
+		acl_block = mlxsw_sp_acl_block_create(mlxsw_sp, block->net);
+		if (!acl_block)
+			return -ENOMEM;
+		block_cb = __tcf_block_cb_register(block,
+						   mlxsw_sp_setup_tc_block_cb_flower,
+						   mlxsw_sp, acl_block);
+		if (IS_ERR(block_cb)) {
+			err = PTR_ERR(block_cb);
+			goto err_cb_register;
+		}
+	} else {
+		acl_block = tcf_block_cb_priv(block_cb);
+	}
+	tcf_block_cb_incref(block_cb);
+	err = mlxsw_sp_acl_block_bind(mlxsw_sp, acl_block,
+				      mlxsw_sp_port, ingress);
+	if (err)
+		goto err_block_bind;
+
+	if (ingress)
+		mlxsw_sp_port->ing_acl_block = acl_block;
+	else
+		mlxsw_sp_port->eg_acl_block = acl_block;
+
+	return 0;
+
+err_block_bind:
+	if (!tcf_block_cb_decref(block_cb)) {
+		__tcf_block_cb_unregister(block_cb);
+err_cb_register:
+		mlxsw_sp_acl_block_destroy(acl_block);
+	}
+	return err;
+}
+
+static void
+mlxsw_sp_setup_tc_block_flower_unbind(struct mlxsw_sp_port *mlxsw_sp_port,
+				      struct tcf_block *block, bool ingress)
+{
+	struct mlxsw_sp *mlxsw_sp = mlxsw_sp_port->mlxsw_sp;
+	struct mlxsw_sp_acl_block *acl_block;
+	struct tcf_block_cb *block_cb;
+	int err;
+
+	block_cb = tcf_block_cb_lookup(block, mlxsw_sp_setup_tc_block_cb_flower,
+				       mlxsw_sp);
+	if (!block_cb)
+		return;
+
+	if (ingress)
+		mlxsw_sp_port->ing_acl_block = NULL;
+	else
+		mlxsw_sp_port->eg_acl_block = NULL;
+
+	acl_block = tcf_block_cb_priv(block_cb);
+	err = mlxsw_sp_acl_block_unbind(mlxsw_sp, acl_block,
+					mlxsw_sp_port, ingress);
+	if (!err && !tcf_block_cb_decref(block_cb)) {
+		__tcf_block_cb_unregister(block_cb);
+		mlxsw_sp_acl_block_destroy(acl_block);
+	}
 }
 
 static int mlxsw_sp_setup_tc_block(struct mlxsw_sp_port *mlxsw_sp_port,
 				   struct tc_block_offload *f)
 {
 	tc_setup_cb_t *cb;
+	bool ingress;
+	int err;
 
-	if (f->binder_type == TCF_BLOCK_BINDER_TYPE_CLSACT_INGRESS)
-		cb = mlxsw_sp_setup_tc_block_cb_ig;
-	else if (f->binder_type == TCF_BLOCK_BINDER_TYPE_CLSACT_EGRESS)
-		cb = mlxsw_sp_setup_tc_block_cb_eg;
-	else
+	if (f->binder_type == TCF_BLOCK_BINDER_TYPE_CLSACT_INGRESS) {
+		cb = mlxsw_sp_setup_tc_block_cb_matchall_ig;
+		ingress = true;
+	} else if (f->binder_type == TCF_BLOCK_BINDER_TYPE_CLSACT_EGRESS) {
+		cb = mlxsw_sp_setup_tc_block_cb_matchall_eg;
+		ingress = false;
+	} else {
 		return -EOPNOTSUPP;
+	}
 
 	switch (f->command) {
 	case TC_BLOCK_BIND:
-		return tcf_block_cb_register(f->block, cb, mlxsw_sp_port,
-					     mlxsw_sp_port);
+		err = tcf_block_cb_register(f->block, cb, mlxsw_sp_port,
+					    mlxsw_sp_port);
+		if (err)
+			return err;
+		err = mlxsw_sp_setup_tc_block_flower_bind(mlxsw_sp_port,
+							  f->block, ingress);
+		if (err) {
+			tcf_block_cb_unregister(f->block, cb, mlxsw_sp_port);
+			return err;
+		}
+		return 0;
 	case TC_BLOCK_UNBIND:
+		mlxsw_sp_setup_tc_block_flower_unbind(mlxsw_sp_port,
+						      f->block, ingress);
 		tcf_block_cb_unregister(f->block, cb, mlxsw_sp_port);
 		return 0;
 	default:
@@ -1842,10 +1956,18 @@ static int mlxsw_sp_feature_hw_tc(struct net_device *dev, bool enable)
 {
 	struct mlxsw_sp_port *mlxsw_sp_port = netdev_priv(dev);
 
-	if (!enable && (mlxsw_sp_port->acl_rule_count ||
-			!list_empty(&mlxsw_sp_port->mall_tc_list))) {
-		netdev_err(dev, "Active offloaded tc filters, can't turn hw_tc_offload off\n");
-		return -EINVAL;
+	if (!enable) {
+		if (mlxsw_sp_acl_block_rule_count(mlxsw_sp_port->ing_acl_block) ||
+		    mlxsw_sp_acl_block_rule_count(mlxsw_sp_port->eg_acl_block) ||
+		    !list_empty(&mlxsw_sp_port->mall_tc_list)) {
+			netdev_err(dev, "Active offloaded tc filters, can't turn hw_tc_offload off\n");
+			return -EINVAL;
+		}
+		mlxsw_sp_acl_block_disable_inc(mlxsw_sp_port->ing_acl_block);
+		mlxsw_sp_acl_block_disable_inc(mlxsw_sp_port->eg_acl_block);
+	} else {
+		mlxsw_sp_acl_block_disable_dec(mlxsw_sp_port->ing_acl_block);
+		mlxsw_sp_acl_block_disable_dec(mlxsw_sp_port->eg_acl_block);
 	}
 	return 0;
 }

drivers/net/ethernet/mellanox/mlxsw/spectrum.h

@@ -260,6 +260,8 @@ struct mlxsw_sp_port {
 	struct list_head vlans_list;
 	struct mlxsw_sp_qdisc *root_qdisc;
 	unsigned acl_rule_count;
+	struct mlxsw_sp_acl_block *ing_acl_block;
+	struct mlxsw_sp_acl_block *eg_acl_block;
 };
 
 static inline bool
@@ -468,8 +470,11 @@ struct mlxsw_sp_acl_profile_ops {
 			   void *priv, void *ruleset_priv);
 	void (*ruleset_del)(struct mlxsw_sp *mlxsw_sp, void *ruleset_priv);
 	int (*ruleset_bind)(struct mlxsw_sp *mlxsw_sp, void *ruleset_priv,
-			    struct net_device *dev, bool ingress);
-	void (*ruleset_unbind)(struct mlxsw_sp *mlxsw_sp, void *ruleset_priv);
+			    struct mlxsw_sp_port *mlxsw_sp_port,
+			    bool ingress);
+	void (*ruleset_unbind)(struct mlxsw_sp *mlxsw_sp, void *ruleset_priv,
+			       struct mlxsw_sp_port *mlxsw_sp_port,
+			       bool ingress);
 	u16 (*ruleset_group_id)(void *ruleset_priv);
 	size_t rule_priv_size;
 	int (*rule_add)(struct mlxsw_sp *mlxsw_sp,
@@ -489,17 +494,34 @@ struct mlxsw_sp_acl_ops {
 				       enum mlxsw_sp_acl_profile profile);
 };
 
+struct mlxsw_sp_acl_block;
 struct mlxsw_sp_acl_ruleset;
 
 /* spectrum_acl.c */
 struct mlxsw_afk *mlxsw_sp_acl_afk(struct mlxsw_sp_acl *acl);
+struct mlxsw_sp *mlxsw_sp_acl_block_mlxsw_sp(struct mlxsw_sp_acl_block *block);
+unsigned int mlxsw_sp_acl_block_rule_count(struct mlxsw_sp_acl_block *block);
+void mlxsw_sp_acl_block_disable_inc(struct mlxsw_sp_acl_block *block);
+void mlxsw_sp_acl_block_disable_dec(struct mlxsw_sp_acl_block *block);
+bool mlxsw_sp_acl_block_disabled(struct mlxsw_sp_acl_block *block);
+struct mlxsw_sp_acl_block *mlxsw_sp_acl_block_create(struct mlxsw_sp *mlxsw_sp,
+						     struct net *net);
+void mlxsw_sp_acl_block_destroy(struct mlxsw_sp_acl_block *block);
+int mlxsw_sp_acl_block_bind(struct mlxsw_sp *mlxsw_sp,
+			    struct mlxsw_sp_acl_block *block,
+			    struct mlxsw_sp_port *mlxsw_sp_port,
+			    bool ingress);
+int mlxsw_sp_acl_block_unbind(struct mlxsw_sp *mlxsw_sp,
+			      struct mlxsw_sp_acl_block *block,
+			      struct mlxsw_sp_port *mlxsw_sp_port,
+			      bool ingress);
 struct mlxsw_sp_acl_ruleset *
-mlxsw_sp_acl_ruleset_lookup(struct mlxsw_sp *mlxsw_sp, struct net_device *dev,
-			    bool ingress, u32 chain_index,
+mlxsw_sp_acl_ruleset_lookup(struct mlxsw_sp *mlxsw_sp,
+			    struct mlxsw_sp_acl_block *block, u32 chain_index,
 			    enum mlxsw_sp_acl_profile profile);
 struct mlxsw_sp_acl_ruleset *
-mlxsw_sp_acl_ruleset_get(struct mlxsw_sp *mlxsw_sp, struct net_device *dev,
-			 bool ingress, u32 chain_index,
+mlxsw_sp_acl_ruleset_get(struct mlxsw_sp *mlxsw_sp,
+			 struct mlxsw_sp_acl_block *block, u32 chain_index,
 			 enum mlxsw_sp_acl_profile profile);
 void mlxsw_sp_acl_ruleset_put(struct mlxsw_sp *mlxsw_sp,
 			      struct mlxsw_sp_acl_ruleset *ruleset);
@@ -566,11 +588,14 @@ void mlxsw_sp_acl_fini(struct mlxsw_sp *mlxsw_sp);
 extern const struct mlxsw_sp_acl_ops mlxsw_sp_acl_tcam_ops;
 
 /* spectrum_flower.c */
-int mlxsw_sp_flower_replace(struct mlxsw_sp_port *mlxsw_sp_port, bool ingress,
+int mlxsw_sp_flower_replace(struct mlxsw_sp *mlxsw_sp,
+			    struct mlxsw_sp_acl_block *block,
 			    struct tc_cls_flower_offload *f);
-void mlxsw_sp_flower_destroy(struct mlxsw_sp_port *mlxsw_sp_port, bool ingress,
+void mlxsw_sp_flower_destroy(struct mlxsw_sp *mlxsw_sp,
+			     struct mlxsw_sp_acl_block *block,
 			     struct tc_cls_flower_offload *f);
-int mlxsw_sp_flower_stats(struct mlxsw_sp_port *mlxsw_sp_port, bool ingress,
+int mlxsw_sp_flower_stats(struct mlxsw_sp *mlxsw_sp,
+			  struct mlxsw_sp_acl_block *block,
 			  struct tc_cls_flower_offload *f);
 
 /* spectrum_qdisc.c */