Merge branch 'dsa-parsing-stage'

Vivien Didelot says:

====================
net: dsa: parsing stage

When registering a DSA switch, there is basically two stages.

The first stage is the parsing of the switch device, from either device
tree or platform data. It fetches the DSA tree to which it belongs, and
validates its ports. The switch device is then added to the tree, and
the second stage is called if this was the last switch of the tree.

The second stage is the setup of the tree, which validates that the tree
is complete, sets up the routing tables, the default CPU port for user
ports, sets up the switch drivers and finally the master interfaces,
which makes the whole switch fabric functional.

This patch series covers the first parsing stage. It fixes the type of
the switch and tree indexes to unsigned int, simplifies the tree
reference counting and the switch and CPU ports parsing.
====================

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

3 files changed, 179 insertions, 140 deletions

diff --git a/include/net/dsa.h b/include/net/dsa.h
index 50e276dc4c01..e54332968417 100644
--- a/include/net/dsa.h
+++ b/include/net/dsa.h
@@ -116,7 +116,7 @@ struct dsa_switch_tree {
 	struct raw_notifier_head	nh;
 
 	/* Tree identifier */
-	u32 tree;
+	unsigned int index;
 
 	/* Number of switches attached to this tree */
 	struct kref refcount;
@@ -209,7 +209,7 @@ struct dsa_switch {
 	 * Parent switch tree, and switch index.
 	 */
 	struct dsa_switch_tree	*dst;
-	int			index;
+	unsigned int		index;
 
 	/* Listener for switch fabric events */
 	struct notifier_block	nb;
diff --git a/net/dsa/dsa2.c b/net/dsa/dsa2.c
index 797d1156b4e6..283104e5ca6a 100644
--- a/net/dsa/dsa2.c
+++ b/net/dsa/dsa2.c
@@ -21,65 +21,77 @@
 
 #include "dsa_priv.h"
 
-static LIST_HEAD(dsa_switch_trees);
+static LIST_HEAD(dsa_tree_list);
 static DEFINE_MUTEX(dsa2_mutex);
 
 static const struct devlink_ops dsa_devlink_ops = {
 };
 
-static struct dsa_switch_tree *dsa_get_dst(u32 tree)
+static struct dsa_switch_tree *dsa_tree_find(int index)
 {
 	struct dsa_switch_tree *dst;
 
-	list_for_each_entry(dst, &dsa_switch_trees, list)
-		if (dst->tree == tree) {
-			kref_get(&dst->refcount);
+	list_for_each_entry(dst, &dsa_tree_list, list)
+		if (dst->index == index)
 			return dst;
-		}
+
 	return NULL;
 }
 
-static void dsa_free_dst(struct kref *ref)
+static struct dsa_switch_tree *dsa_tree_alloc(int index)
 {
-	struct dsa_switch_tree *dst = container_of(ref, struct dsa_switch_tree,
-						   refcount);
+	struct dsa_switch_tree *dst;
 
-	list_del(&dst->list);
-	kfree(dst);
+	dst = kzalloc(sizeof(*dst), GFP_KERNEL);
+	if (!dst)
+		return NULL;
+
+	dst->index = index;
+
+	INIT_LIST_HEAD(&dst->list);
+	list_add_tail(&dsa_tree_list, &dst->list);
+
+	/* Initialize the reference counter to the number of switches, not 1 */
+	kref_init(&dst->refcount);
+	refcount_set(&dst->refcount.refcount, 0);
+
+	return dst;
 }
 
-static void dsa_put_dst(struct dsa_switch_tree *dst)
+static void dsa_tree_free(struct dsa_switch_tree *dst)
 {
-	kref_put(&dst->refcount, dsa_free_dst);
+	list_del(&dst->list);
+	kfree(dst);
 }
 
-static struct dsa_switch_tree *dsa_add_dst(u32 tree)
+static struct dsa_switch_tree *dsa_tree_touch(int index)
 {
 	struct dsa_switch_tree *dst;
 
-	dst = kzalloc(sizeof(*dst), GFP_KERNEL);
+	dst = dsa_tree_find(index);
 	if (!dst)
-		return NULL;
-	dst->tree = tree;
-	INIT_LIST_HEAD(&dst->list);
-	list_add_tail(&dsa_switch_trees, &dst->list);
-	kref_init(&dst->refcount);
+		dst = dsa_tree_alloc(index);
 
 	return dst;
 }
 
-static void dsa_dst_add_ds(struct dsa_switch_tree *dst,
-			   struct dsa_switch *ds, u32 index)
+static void dsa_tree_get(struct dsa_switch_tree *dst)
 {
 	kref_get(&dst->refcount);
-	dst->ds[index] = ds;
 }
 
-static void dsa_dst_del_ds(struct dsa_switch_tree *dst,
-			   struct dsa_switch *ds, u32 index)
+static void dsa_tree_release(struct kref *ref)
 {
-	dst->ds[index] = NULL;
-	kref_put(&dst->refcount, dsa_free_dst);
+	struct dsa_switch_tree *dst;
+
+	dst = container_of(ref, struct dsa_switch_tree, refcount);
+
+	dsa_tree_free(dst);
+}
+
+static void dsa_tree_put(struct dsa_switch_tree *dst)
+{
+	kref_put(&dst->refcount, dsa_tree_release);
 }
 
 /* For platform data configurations, we need to have a valid name argument to
@@ -454,20 +466,56 @@ static void dsa_dst_unapply(struct dsa_switch_tree *dst)
 
 	dst->cpu_dp = NULL;
 
-	pr_info("DSA: tree %d unapplied\n", dst->tree);
+	pr_info("DSA: tree %d unapplied\n", dst->index);
 	dst->applied = false;
 }
 
-static int dsa_cpu_parse(struct dsa_port *port, u32 index,
-			 struct dsa_switch_tree *dst,
-			 struct dsa_switch *ds)
+static void dsa_tree_remove_switch(struct dsa_switch_tree *dst,
+				   unsigned int index)
 {
+	dst->ds[index] = NULL;
+	dsa_tree_put(dst);
+}
+
+static int dsa_tree_add_switch(struct dsa_switch_tree *dst,
+			       struct dsa_switch *ds)
+{
+	unsigned int index = ds->index;
+
+	if (dst->ds[index])
+		return -EBUSY;
+
+	dsa_tree_get(dst);
+	dst->ds[index] = ds;
+
+	return 0;
+}
+
+static int dsa_port_parse_user(struct dsa_port *dp, const char *name)
+{
+	if (!name)
+		name = "eth%d";
+
+	dp->type = DSA_PORT_TYPE_USER;
+	dp->name = name;
+
+	return 0;
+}
+
+static int dsa_port_parse_dsa(struct dsa_port *dp)
+{
+	dp->type = DSA_PORT_TYPE_DSA;
+
+	return 0;
+}
+
+static int dsa_port_parse_cpu(struct dsa_port *dp, struct net_device *master)
+{
+	struct dsa_switch *ds = dp->ds;
+	struct dsa_switch_tree *dst = ds->dst;
 	const struct dsa_device_ops *tag_ops;
 	enum dsa_tag_protocol tag_protocol;
 
-	if (!dst->cpu_dp)
-		dst->cpu_dp = port;
-
 	tag_protocol = ds->ops->get_tag_protocol(ds);
 	tag_ops = dsa_resolve_tag_protocol(tag_protocol);
 	if (IS_ERR(tag_ops)) {
@@ -475,11 +523,21 @@ static int dsa_cpu_parse(struct dsa_port *port, u32 index,
 		return PTR_ERR(tag_ops);
 	}
 
-	dst->cpu_dp->tag_ops = tag_ops;
+	dp->type = DSA_PORT_TYPE_CPU;
+	dp->rcv = tag_ops->rcv;
+	dp->tag_ops = tag_ops;
+	dp->master = master;
+	dp->dst = dst;
+
+	return 0;
+}
 
-	/* Make a few copies for faster access in master receive hot path */
-	dst->cpu_dp->rcv = dst->cpu_dp->tag_ops->rcv;
-	dst->cpu_dp->dst = dst;
+static int dsa_cpu_parse(struct dsa_port *port, u32 index,
+			 struct dsa_switch_tree *dst,
+			 struct dsa_switch *ds)
+{
+	if (!dst->cpu_dp)
+		dst->cpu_dp = port;
 
 	return 0;
 }
@@ -504,7 +562,7 @@ static int dsa_ds_parse(struct dsa_switch_tree *dst, struct dsa_switch *ds)
 
 	}
 
-	pr_info("DSA: switch %d %d parsed\n", dst->tree, ds->index);
+	pr_info("DSA: switch %d %d parsed\n", dst->index, ds->index);
 
 	return 0;
 }
@@ -549,7 +607,7 @@ static int dsa_dst_parse(struct dsa_switch_tree *dst)
 		}
 	}
 
-	pr_info("DSA: tree %d parsed\n", dst->tree);
+	pr_info("DSA: tree %d parsed\n", dst->index);
 
 	return 0;
 }
@@ -557,8 +615,10 @@ static int dsa_dst_parse(struct dsa_switch_tree *dst)
 static int dsa_port_parse_of(struct dsa_port *dp, struct device_node *dn)
 {
 	struct device_node *ethernet = of_parse_phandle(dn, "ethernet", 0);
-	struct device_node *link = of_parse_phandle(dn, "link", 0);
 	const char *name = of_get_property(dn, "label", NULL);
+	bool link = of_property_read_bool(dn, "link");
+
+	dp->dn = dn;
 
 	if (ethernet) {
 		struct net_device *master;
@@ -567,24 +627,17 @@ static int dsa_port_parse_of(struct dsa_port *dp, struct device_node *dn)
 		if (!master)
 			return -EPROBE_DEFER;
 
-		dp->type = DSA_PORT_TYPE_CPU;
-		dp->master = master;
-	} else if (link) {
-		dp->type = DSA_PORT_TYPE_DSA;
-	} else {
-		if (!name)
-			name = "eth%d";
-
-		dp->type = DSA_PORT_TYPE_USER;
-		dp->name = name;
+		return dsa_port_parse_cpu(dp, master);
 	}
 
-	dp->dn = dn;
+	if (link)
+		return dsa_port_parse_dsa(dp);
 
-	return 0;
+	return dsa_port_parse_user(dp, name);
 }
 
-static int dsa_parse_ports_of(struct device_node *dn, struct dsa_switch *ds)
+static int dsa_switch_parse_ports_of(struct dsa_switch *ds,
+				     struct device_node *dn)
 {
 	struct device_node *ports, *port;
 	struct dsa_port *dp;
@@ -615,6 +668,39 @@ static int dsa_parse_ports_of(struct device_node *dn, struct dsa_switch *ds)
 	return 0;
 }
 
+static int dsa_switch_parse_member_of(struct dsa_switch *ds,
+				      struct device_node *dn)
+{
+	u32 m[2] = { 0, 0 };
+	int sz;
+
+	/* Don't error out if this optional property isn't found */
+	sz = of_property_read_variable_u32_array(dn, "dsa,member", m, 2, 2);
+	if (sz < 0 && sz != -EINVAL)
+		return sz;
+
+	ds->index = m[1];
+	if (ds->index >= DSA_MAX_SWITCHES)
+		return -EINVAL;
+
+	ds->dst = dsa_tree_touch(m[0]);
+	if (!ds->dst)
+		return -ENOMEM;
+
+	return 0;
+}
+
+static int dsa_switch_parse_of(struct dsa_switch *ds, struct device_node *dn)
+{
+	int err;
+
+	err = dsa_switch_parse_member_of(ds, dn);
+	if (err)
+		return err;
+
+	return dsa_switch_parse_ports_of(ds, dn);
+}
+
 static int dsa_port_parse(struct dsa_port *dp, const char *name,
 			  struct device *dev)
 {
@@ -627,20 +713,17 @@ static int dsa_port_parse(struct dsa_port *dp, const char *name,
 
 		dev_put(master);
 
-		dp->type = DSA_PORT_TYPE_CPU;
-		dp->master = master;
-	} else if (!strcmp(name, "dsa")) {
-		dp->type = DSA_PORT_TYPE_DSA;
-	} else {
-		dp->type = DSA_PORT_TYPE_USER;
+		return dsa_port_parse_cpu(dp, master);
 	}
 
-	dp->name = name;
+	if (!strcmp(name, "dsa"))
+		return dsa_port_parse_dsa(dp);
 
-	return 0;
+	return dsa_port_parse_user(dp, name);
 }
 
-static int dsa_parse_ports(struct dsa_chip_data *cd, struct dsa_switch *ds)
+static int dsa_switch_parse_ports(struct dsa_switch *ds,
+				  struct dsa_chip_data *cd)
 {
 	bool valid_name_found = false;
 	struct dsa_port *dp;
@@ -670,40 +753,19 @@ static int dsa_parse_ports(struct dsa_chip_data *cd, struct dsa_switch *ds)
 	return 0;
 }
 
-static int dsa_parse_member_dn(struct device_node *np, u32 *tree, u32 *index)
+static int dsa_switch_parse(struct dsa_switch *ds, struct dsa_chip_data *cd)
 {
-	int err;
-
-	*tree = *index = 0;
-
-	err = of_property_read_u32_index(np, "dsa,member", 0, tree);
-	if (err) {
-		/* Does not exist, but it is optional */
-		if (err == -EINVAL)
-			return 0;
-		return err;
-	}
+	ds->cd = cd;
 
-	err = of_property_read_u32_index(np, "dsa,member", 1, index);
-	if (err)
-		return err;
-
-	if (*index >= DSA_MAX_SWITCHES)
-		return -EINVAL;
-
-	return 0;
-}
-
-static int dsa_parse_member(struct dsa_chip_data *pd, u32 *tree, u32 *index)
-{
-	if (!pd)
-		return -ENODEV;
-
-	/* We do not support complex trees with dsa_chip_data */
-	*tree = 0;
-	*index = 0;
+	/* We don't support interconnected switches nor multiple trees via
+	 * platform data, so this is the unique switch of the tree.
+	 */
+	ds->index = 0;
+	ds->dst = dsa_tree_touch(0);
+	if (!ds->dst)
+		return -ENOMEM;
 
-	return 0;
+	return dsa_switch_parse_ports(ds, cd);
 }
 
 static int _dsa_register_switch(struct dsa_switch *ds)
@@ -711,58 +773,37 @@ static int _dsa_register_switch(struct dsa_switch *ds)
 	struct dsa_chip_data *pdata = ds->dev->platform_data;
 	struct device_node *np = ds->dev->of_node;
 	struct dsa_switch_tree *dst;
-	u32 tree, index;
+	unsigned int index;
 	int i, err;
 
-	if (np) {
-		err = dsa_parse_member_dn(np, &tree, &index);
-		if (err)
-			return err;
+	if (np)
+		err = dsa_switch_parse_of(ds, np);
+	else if (pdata)
+		err = dsa_switch_parse(ds, pdata);
+	else
+		err = -ENODEV;
 
-		err = dsa_parse_ports_of(np, ds);
-		if (err)
-			return err;
-	} else {
-		err = dsa_parse_member(pdata, &tree, &index);
-		if (err)
-			return err;
-
-		err = dsa_parse_ports(pdata, ds);
-		if (err)
-			return err;
-	}
-
-	dst = dsa_get_dst(tree);
-	if (!dst) {
-		dst = dsa_add_dst(tree);
-		if (!dst)
-			return -ENOMEM;
-	}
-
-	if (dst->ds[index]) {
-		err = -EBUSY;
-		goto out;
-	}
+	if (err)
+		return err;
 
-	ds->dst = dst;
-	ds->index = index;
-	ds->cd = pdata;
+	index = ds->index;
+	dst = ds->dst;
 
 	/* Initialize the routing table */
 	for (i = 0; i < DSA_MAX_SWITCHES; ++i)
 		ds->rtable[i] = DSA_RTABLE_NONE;
 
-	dsa_dst_add_ds(dst, ds, index);
+	err = dsa_tree_add_switch(dst, ds);
+	if (err)
+		return err;
 
 	err = dsa_dst_complete(dst);
 	if (err < 0)
 		goto out_del_dst;
 
-	if (err == 1) {
-		/* Not all switches registered yet */
-		err = 0;
-		goto out;
-	}
+	/* Not all switches registered yet */
+	if (err == 1)
+		return 0;
 
 	if (dst->applied) {
 		pr_info("DSA: Disjoint trees?\n");
@@ -779,13 +820,10 @@ static int _dsa_register_switch(struct dsa_switch *ds)
 		goto out_del_dst;
 	}
 
-	dsa_put_dst(dst);
 	return 0;
 
 out_del_dst:
-	dsa_dst_del_ds(dst, ds, ds->index);
-out:
-	dsa_put_dst(dst);
+	dsa_tree_remove_switch(dst, index);
 
 	return err;
 }
@@ -827,10 +865,11 @@ EXPORT_SYMBOL_GPL(dsa_register_switch);
 static void _dsa_unregister_switch(struct dsa_switch *ds)
 {
 	struct dsa_switch_tree *dst = ds->dst;
+	unsigned int index = ds->index;
 
 	dsa_dst_unapply(dst);
 
-	dsa_dst_del_ds(dst, ds, ds->index);
+	dsa_tree_remove_switch(dst, index);
 }
 
 void dsa_unregister_switch(struct dsa_switch *ds)
diff --git a/net/dsa/slave.c b/net/dsa/slave.c
index 9b75d0ac4092..814ced75a0cc 100644
--- a/net/dsa/slave.c
+++ b/net/dsa/slave.c
@@ -55,7 +55,7 @@ void dsa_slave_mii_bus_init(struct dsa_switch *ds)
 	ds->slave_mii_bus->read = dsa_slave_phy_read;
 	ds->slave_mii_bus->write = dsa_slave_phy_write;
 	snprintf(ds->slave_mii_bus->id, MII_BUS_ID_SIZE, "dsa-%d.%d",
-		 ds->dst->tree, ds->index);
+		 ds->dst->index, ds->index);
 	ds->slave_mii_bus->parent = ds->dev;
 	ds->slave_mii_bus->phy_mask = ~ds->phys_mii_mask;
 }