Merge branch 'net-Introduce-ndo_get_port_parent_id'

Florian Fainelli says:

====================
net: Introduce ndo_get_port_parent_id()

Based on discussion with Ido and feedback from Jakub there are clearly
two classes of users that implement SWITCHDEV_ATTR_ID_PORT_PARENT_ID:

- PF/VF drivers which typically only implement return the port's parent
  ID, yet have to implement switchdev_port_attr_get() just for that

- Ethernet switch drivers: mlxsw, ocelot, DSA, etc. which implement more
  attributes which we want to be able to eventually veto in the context
  of the caller, thus making them candidates for using a blocking notifier
  chain

Changes in v4:

- remove superfluous net/switchdev.h inclusions in a few files
- added Jiri's Acked-by where given
- removed err = -EOPNOTSUPP initializations
- changed according to Jiri's suggestion in net/ipv4/ipmr.c

Changes in v3:

- keep ethsw's switchdev_ops assignment
- remove inclusion of net/switchdev.h in netdevsim which is no longer
  necesary

Changes in v2:

- resolved build failures spotted by kbuild test robot
- added helpers functions into the core network device layer:
  dev_get_port_parent_id() and netdev_port_same_parent_id();
- added support for recursion to lower devices

Changes from RFC:

- introduce a ndo_get_port_parent_id() and convert all relevant drivers
  to use it

- get rid of SWITCHDEV_ATTR_ID_PORT_PARENT_ID

A subsequent set of patches will convert switchdev_port_attr_set() to
use a blocking notifier call, and still get rid of
switchdev_port_attr_get() altogether.
====================

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

7 files changed, 83 insertions, 58 deletions

diff --git a/net/bridge/br_switchdev.c b/net/bridge/br_switchdev.c
index 4d2b9eb7604a..db9e8ab96d48 100644
--- a/net/bridge/br_switchdev.c
+++ b/net/bridge/br_switchdev.c
@@ -14,7 +14,7 @@ static int br_switchdev_mark_get(struct net_bridge *br, struct net_device *dev)
 
 	/* dev is yet to be added to the port list. */
 	list_for_each_entry(p, &br->port_list, list) {
-		if (switchdev_port_same_parent_id(dev, p->dev))
+		if (netdev_port_same_parent_id(dev, p->dev))
 			return p->offload_fwd_mark;
 	}
 
@@ -23,15 +23,12 @@ static int br_switchdev_mark_get(struct net_bridge *br, struct net_device *dev)
 
 int nbp_switchdev_mark_set(struct net_bridge_port *p)
 {
-	struct switchdev_attr attr = {
-		.orig_dev = p->dev,
-		.id = SWITCHDEV_ATTR_ID_PORT_PARENT_ID,
-	};
+	struct netdev_phys_item_id ppid = { };
 	int err;
 
 	ASSERT_RTNL();
 
-	err = switchdev_port_attr_get(p->dev, &attr);
+	err = dev_get_port_parent_id(p->dev, &ppid, true);
 	if (err) {
 		if (err == -EOPNOTSUPP)
 			return 0;
diff --git a/net/core/dev.c b/net/core/dev.c
index bfa4be42afff..8c6d5cf8a308 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -7878,6 +7878,63 @@ int dev_get_phys_port_name(struct net_device *dev,
 EXPORT_SYMBOL(dev_get_phys_port_name);
 
 /**
+ *	dev_get_port_parent_id - Get the device's port parent identifier
+ *	@dev: network device
+ *	@ppid: pointer to a storage for the port's parent identifier
+ *	@recurse: allow/disallow recursion to lower devices
+ *
+ *	Get the devices's port parent identifier
+ */
+int dev_get_port_parent_id(struct net_device *dev,
+			   struct netdev_phys_item_id *ppid,
+			   bool recurse)
+{
+	const struct net_device_ops *ops = dev->netdev_ops;
+	struct netdev_phys_item_id first = { };
+	struct net_device *lower_dev;
+	struct list_head *iter;
+	int err = -EOPNOTSUPP;
+
+	if (ops->ndo_get_port_parent_id)
+		return ops->ndo_get_port_parent_id(dev, ppid);
+
+	if (!recurse)
+		return err;
+
+	netdev_for_each_lower_dev(dev, lower_dev, iter) {
+		err = dev_get_port_parent_id(lower_dev, ppid, recurse);
+		if (err)
+			break;
+		if (!first.id_len)
+			first = *ppid;
+		else if (memcmp(&first, ppid, sizeof(*ppid)))
+			return -ENODATA;
+	}
+
+	return err;
+}
+EXPORT_SYMBOL(dev_get_port_parent_id);
+
+/**
+ *	netdev_port_same_parent_id - Indicate if two network devices have
+ *	the same port parent identifier
+ *	@a: first network device
+ *	@b: second network device
+ */
+bool netdev_port_same_parent_id(struct net_device *a, struct net_device *b)
+{
+	struct netdev_phys_item_id a_id = { };
+	struct netdev_phys_item_id b_id = { };
+
+	if (dev_get_port_parent_id(a, &a_id, true) ||
+	    dev_get_port_parent_id(b, &b_id, true))
+		return false;
+
+	return netdev_phys_item_id_same(&a_id, &b_id);
+}
+EXPORT_SYMBOL(netdev_port_same_parent_id);
+
+/**
  *	dev_change_proto_down - update protocol port state information
  *	@dev: device
  *	@proto_down: new value
diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c
index ff9fd2bb4ce4..7c5061123ead 100644
--- a/net/core/net-sysfs.c
+++ b/net/core/net-sysfs.c
@@ -12,7 +12,6 @@
 #include <linux/capability.h>
 #include <linux/kernel.h>
 #include <linux/netdevice.h>
-#include <net/switchdev.h>
 #include <linux/if_arp.h>
 #include <linux/slab.h>
 #include <linux/sched/signal.h>
@@ -501,16 +500,11 @@ static ssize_t phys_switch_id_show(struct device *dev,
 		return restart_syscall();
 
 	if (dev_isalive(netdev)) {
-		struct switchdev_attr attr = {
-			.orig_dev = netdev,
-			.id = SWITCHDEV_ATTR_ID_PORT_PARENT_ID,
-			.flags = SWITCHDEV_F_NO_RECURSE,
-		};
+		struct netdev_phys_item_id ppid = { };
 
-		ret = switchdev_port_attr_get(netdev, &attr);
+		ret = dev_get_port_parent_id(netdev, &ppid, false);
 		if (!ret)
-			ret = sprintf(buf, "%*phN\n", attr.u.ppid.id_len,
-				      attr.u.ppid.id);
+			ret = sprintf(buf, "%*phN\n", ppid.id_len, ppid.id);
 	}
 	rtnl_unlock();
 
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index f5a98082ac7a..a51cab95ba64 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -46,7 +46,6 @@
 
 #include <linux/inet.h>
 #include <linux/netdevice.h>
-#include <net/switchdev.h>
 #include <net/ip.h>
 #include <net/protocol.h>
 #include <net/arp.h>
@@ -1146,22 +1145,17 @@ static int rtnl_phys_port_name_fill(struct sk_buff *skb, struct net_device *dev)
 
 static int rtnl_phys_switch_id_fill(struct sk_buff *skb, struct net_device *dev)
 {
+	struct netdev_phys_item_id ppid = { };
 	int err;
-	struct switchdev_attr attr = {
-		.orig_dev = dev,
-		.id = SWITCHDEV_ATTR_ID_PORT_PARENT_ID,
-		.flags = SWITCHDEV_F_NO_RECURSE,
-	};
 
-	err = switchdev_port_attr_get(dev, &attr);
+	err = dev_get_port_parent_id(dev, &ppid, false);
 	if (err) {
 		if (err == -EOPNOTSUPP)
 			return 0;
 		return err;
 	}
 
-	if (nla_put(skb, IFLA_PHYS_SWITCH_ID, attr.u.ppid.id_len,
-		    attr.u.ppid.id))
+	if (nla_put(skb, IFLA_PHYS_SWITCH_ID, ppid.id_len, ppid.id))
 		return -EMSGSIZE;
 
 	return 0;
diff --git a/net/dsa/slave.c b/net/dsa/slave.c
index 91de3a663226..70395a0ae52e 100644
--- a/net/dsa/slave.c
+++ b/net/dsa/slave.c
@@ -362,18 +362,23 @@ static int dsa_slave_port_obj_del(struct net_device *dev,
 	return err;
 }
 
-static int dsa_slave_port_attr_get(struct net_device *dev,
-				   struct switchdev_attr *attr)
+static int dsa_slave_get_port_parent_id(struct net_device *dev,
+					struct netdev_phys_item_id *ppid)
 {
 	struct dsa_port *dp = dsa_slave_to_port(dev);
 	struct dsa_switch *ds = dp->ds;
 	struct dsa_switch_tree *dst = ds->dst;
 
+	ppid->id_len = sizeof(dst->index);
+	memcpy(&ppid->id, &dst->index, ppid->id_len);
+
+	return 0;
+}
+
+static int dsa_slave_port_attr_get(struct net_device *dev,
+				   struct switchdev_attr *attr)
+{
 	switch (attr->id) {
-	case SWITCHDEV_ATTR_ID_PORT_PARENT_ID:
-		attr->u.ppid.id_len = sizeof(dst->index);
-		memcpy(&attr->u.ppid.id, &dst->index, attr->u.ppid.id_len);
-		break;
 	case SWITCHDEV_ATTR_ID_PORT_BRIDGE_FLAGS_SUPPORT:
 		attr->u.brport_flags_support = 0;
 		break;
@@ -1046,6 +1051,7 @@ static const struct net_device_ops dsa_slave_netdev_ops = {
 	.ndo_get_phys_port_name	= dsa_slave_get_phys_port_name,
 	.ndo_setup_tc		= dsa_slave_setup_tc,
 	.ndo_get_stats64	= dsa_slave_get_stats64,
+	.ndo_get_port_parent_id	= dsa_slave_get_port_parent_id,
 };
 
 static const struct switchdev_ops dsa_slave_switchdev_ops = {
diff --git a/net/ipv4/ipmr.c b/net/ipv4/ipmr.c
index fb99002c3d4e..e536970557dd 100644
--- a/net/ipv4/ipmr.c
+++ b/net/ipv4/ipmr.c
@@ -67,7 +67,6 @@
 #include <net/fib_rules.h>
 #include <linux/netconf.h>
 #include <net/nexthop.h>
-#include <net/switchdev.h>
 
 #include <linux/nospec.h>
 
@@ -837,10 +836,8 @@ static void ipmr_update_thresholds(struct mr_table *mrt, struct mr_mfc *cache,
 static int vif_add(struct net *net, struct mr_table *mrt,
 		   struct vifctl *vifc, int mrtsock)
 {
+	struct netdev_phys_item_id ppid = { };
 	int vifi = vifc->vifc_vifi;
-	struct switchdev_attr attr = {
-		.id = SWITCHDEV_ATTR_ID_PORT_PARENT_ID,
-	};
 	struct vif_device *v = &mrt->vif_table[vifi];
 	struct net_device *dev;
 	struct in_device *in_dev;
@@ -919,10 +916,10 @@ static int vif_add(struct net *net, struct mr_table *mrt,
 			vifc->vifc_flags | (!mrtsock ? VIFF_STATIC : 0),
 			(VIFF_TUNNEL | VIFF_REGISTER));
 
-	attr.orig_dev = dev;
-	if (!switchdev_port_attr_get(dev, &attr)) {
-		memcpy(v->dev_parent_id.id, attr.u.ppid.id, attr.u.ppid.id_len);
-		v->dev_parent_id.id_len = attr.u.ppid.id_len;
+	err = dev_get_port_parent_id(dev, &ppid, true);
+	if (err == 0) {
+		memcpy(v->dev_parent_id.id, ppid.id, ppid.id_len);
+		v->dev_parent_id.id_len = ppid.id_len;
 	} else {
 		v->dev_parent_id.id_len = 0;
 	}
diff --git a/net/switchdev/switchdev.c b/net/switchdev/switchdev.c
index cd78253de31d..7e1357db33d7 100644
--- a/net/switchdev/switchdev.c
+++ b/net/switchdev/switchdev.c
@@ -592,26 +592,6 @@ int call_switchdev_blocking_notifiers(unsigned long val, struct net_device *dev,
 }
 EXPORT_SYMBOL_GPL(call_switchdev_blocking_notifiers);
 
-bool switchdev_port_same_parent_id(struct net_device *a,
-				   struct net_device *b)
-{
-	struct switchdev_attr a_attr = {
-		.orig_dev = a,
-		.id = SWITCHDEV_ATTR_ID_PORT_PARENT_ID,
-	};
-	struct switchdev_attr b_attr = {
-		.orig_dev = b,
-		.id = SWITCHDEV_ATTR_ID_PORT_PARENT_ID,
-	};
-
-	if (switchdev_port_attr_get(a, &a_attr) ||
-	    switchdev_port_attr_get(b, &b_attr))
-		return false;
-
-	return netdev_phys_item_id_same(&a_attr.u.ppid, &b_attr.u.ppid);
-}
-EXPORT_SYMBOL_GPL(switchdev_port_same_parent_id);
-
 static int __switchdev_handle_port_obj_add(struct net_device *dev,
 			struct switchdev_notifier_port_obj_info *port_obj_info,
 			bool (*check_cb)(const struct net_device *dev),