net: dsa: Add new binding implementation

The existing DSA binding has a number of limitations and problems. The
main problem is that it cannot represent a switch as a linux device,
hanging off some bus. It is limited to one CPU port. The DSA platform
device is artificial, and does not really represent hardware.

Implement a new binding which can be embedded into any type of node on
a bus to represent one switch device, and its links to other switches.

Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 654 insertions, 0 deletions

diff --git a/net/dsa/dsa2.c b/net/dsa/dsa2.c
new file mode 100644
index 000000000000..80dfe08db825
--- /dev/null
+++ b/net/dsa/dsa2.c
@@ -0,0 +1,654 @@
+/*
+ * net/dsa/dsa2.c - Hardware switch handling, binding version 2
+ * Copyright (c) 2008-2009 Marvell Semiconductor
+ * Copyright (c) 2013 Florian Fainelli <florian@openwrt.org>
+ * Copyright (c) 2016 Andrew Lunn <andrew@lunn.ch>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/list.h>
+#include <linux/slab.h>
+#include <linux/rtnetlink.h>
+#include <net/dsa.h>
+#include <linux/of.h>
+#include <linux/of_net.h>
+#include "dsa_priv.h"
+
+static LIST_HEAD(dsa_switch_trees);
+static DEFINE_MUTEX(dsa2_mutex);
+
+static struct dsa_switch_tree *dsa_get_dst(u32 tree)
+{
+	struct dsa_switch_tree *dst;
+
+	list_for_each_entry(dst, &dsa_switch_trees, list)
+		if (dst->tree == tree)
+			return dst;
+	return NULL;
+}
+
+static void dsa_free_dst(struct kref *ref)
+{
+	struct dsa_switch_tree *dst = container_of(ref, struct dsa_switch_tree,
+						   refcount);
+
+	list_del(&dst->list);
+	kfree(dst);
+}
+
+static void dsa_put_dst(struct dsa_switch_tree *dst)
+{
+	kref_put(&dst->refcount, dsa_free_dst);
+}
+
+static struct dsa_switch_tree *dsa_add_dst(u32 tree)
+{
+	struct dsa_switch_tree *dst;
+
+	dst = kzalloc(sizeof(*dst), GFP_KERNEL);
+	if (!dst)
+		return NULL;
+	dst->tree = tree;
+	dst->cpu_switch = -1;
+	INIT_LIST_HEAD(&dst->list);
+	list_add_tail(&dsa_switch_trees, &dst->list);
+	kref_init(&dst->refcount);
+
+	return dst;
+}
+
+static void dsa_dst_add_ds(struct dsa_switch_tree *dst,
+			   struct dsa_switch *ds, u32 index)
+{
+	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)
+{
+	dst->ds[index] = NULL;
+	kref_put(&dst->refcount, dsa_free_dst);
+}
+
+static bool dsa_port_is_dsa(struct device_node *port)
+{
+	const char *name;
+
+	name = of_get_property(port, "label", NULL);
+	if (!name)
+		return false;
+
+	if (!strcmp(name, "dsa"))
+		return true;
+
+	return false;
+}
+
+static bool dsa_port_is_cpu(struct device_node *port)
+{
+	const char *name;
+
+	name = of_get_property(port, "label", NULL);
+	if (!name)
+		return false;
+
+	if (!strcmp(name, "cpu"))
+		return true;
+
+	return false;
+}
+
+static bool dsa_ds_find_port(struct dsa_switch *ds,
+			     struct device_node *port)
+{
+	u32 index;
+
+	for (index = 0; index < DSA_MAX_PORTS; index++)
+		if (ds->ports[index].dn == port)
+			return true;
+	return false;
+}
+
+static struct dsa_switch *dsa_dst_find_port(struct dsa_switch_tree *dst,
+					    struct device_node *port)
+{
+	struct dsa_switch *ds;
+	u32 index;
+
+	for (index = 0; index < DSA_MAX_SWITCHES; index++) {
+		ds = dst->ds[index];
+		if (!ds)
+			continue;
+
+		if (dsa_ds_find_port(ds, port))
+			return ds;
+	}
+
+	return NULL;
+}
+
+static int dsa_port_complete(struct dsa_switch_tree *dst,
+			     struct dsa_switch *src_ds,
+			     struct device_node *port,
+			     u32 src_port)
+{
+	struct device_node *link;
+	int index;
+	struct dsa_switch *dst_ds;
+
+	for (index = 0;; index++) {
+		link = of_parse_phandle(port, "link", index);
+		if (!link)
+			break;
+
+		dst_ds = dsa_dst_find_port(dst, link);
+		of_node_put(link);
+
+		if (!dst_ds)
+			return 1;
+
+		src_ds->rtable[dst_ds->index] = src_port;
+	}
+
+	return 0;
+}
+
+/* A switch is complete if all the DSA ports phandles point to ports
+ * known in the tree. A return value of 1 means the tree is not
+ * complete. This is not an error condition. A value of 0 is
+ * success.
+ */
+static int dsa_ds_complete(struct dsa_switch_tree *dst, struct dsa_switch *ds)
+{
+	struct device_node *port;
+	u32 index;
+	int err;
+
+	for (index = 0; index < DSA_MAX_PORTS; index++) {
+		port = ds->ports[index].dn;
+		if (!port)
+			continue;
+
+		if (!dsa_port_is_dsa(port))
+			continue;
+
+		err = dsa_port_complete(dst, ds, port, index);
+		if (err != 0)
+			return err;
+
+		ds->dsa_port_mask |= BIT(index);
+	}
+
+	return 0;
+}
+
+/* A tree is complete if all the DSA ports phandles point to ports
+ * known in the tree. A return value of 1 means the tree is not
+ * complete. This is not an error condition. A value of 0 is
+ * success.
+ */
+static int dsa_dst_complete(struct dsa_switch_tree *dst)
+{
+	struct dsa_switch *ds;
+	u32 index;
+	int err;
+
+	for (index = 0; index < DSA_MAX_SWITCHES; index++) {
+		ds = dst->ds[index];
+		if (!ds)
+			continue;
+
+		err = dsa_ds_complete(dst, ds);
+		if (err != 0)
+			return err;
+	}
+
+	return 0;
+}
+
+static int dsa_dsa_port_apply(struct device_node *port, u32 index,
+			      struct dsa_switch *ds)
+{
+	int err;
+
+	err = dsa_cpu_dsa_setup(ds, ds->dev, port, index);
+	if (err) {
+		dev_warn(ds->dev, "Failed to setup dsa port %d: %d\n",
+			 index, err);
+		return err;
+	}
+
+	return 0;
+}
+
+static void dsa_dsa_port_unapply(struct device_node *port, u32 index,
+				 struct dsa_switch *ds)
+{
+	dsa_cpu_dsa_destroy(port);
+}
+
+static int dsa_cpu_port_apply(struct device_node *port, u32 index,
+			      struct dsa_switch *ds)
+{
+	int err;
+
+	err = dsa_cpu_dsa_setup(ds, ds->dev, port, index);
+	if (err) {
+		dev_warn(ds->dev, "Failed to setup cpu port %d: %d\n",
+			 index, err);
+		return err;
+	}
+
+	ds->cpu_port_mask |= BIT(index);
+
+	return 0;
+}
+
+static void dsa_cpu_port_unapply(struct device_node *port, u32 index,
+				 struct dsa_switch *ds)
+{
+	dsa_cpu_dsa_destroy(port);
+	ds->cpu_port_mask &= ~BIT(index);
+
+}
+
+static int dsa_user_port_apply(struct device_node *port, u32 index,
+			       struct dsa_switch *ds)
+{
+	const char *name;
+	int err;
+
+	name = of_get_property(port, "label", NULL);
+
+	err = dsa_slave_create(ds, ds->dev, index, name);
+	if (err) {
+		dev_warn(ds->dev, "Failed to create slave %d: %d\n",
+			 index, err);
+		return err;
+	}
+
+	return 0;
+}
+
+static void dsa_user_port_unapply(struct device_node *port, u32 index,
+				  struct dsa_switch *ds)
+{
+	if (ds->ports[index].netdev) {
+		dsa_slave_destroy(ds->ports[index].netdev);
+		ds->ports[index].netdev = NULL;
+	}
+}
+
+static int dsa_ds_apply(struct dsa_switch_tree *dst, struct dsa_switch *ds)
+{
+	struct device_node *port;
+	u32 index;
+	int err;
+
+	err = ds->drv->setup(ds);
+	if (err < 0)
+		return err;
+
+	err = ds->drv->set_addr(ds, dst->master_netdev->dev_addr);
+	if (err < 0)
+		return err;
+
+	err = ds->drv->set_addr(ds, dst->master_netdev->dev_addr);
+	if (err < 0)
+		return err;
+
+	for (index = 0; index < DSA_MAX_PORTS; index++) {
+		port = ds->ports[index].dn;
+		if (!port)
+			continue;
+
+		if (dsa_port_is_dsa(port)) {
+			err = dsa_dsa_port_apply(port, index, ds);
+			if (err)
+				return err;
+			continue;
+		}
+
+		if (dsa_port_is_cpu(port)) {
+			err = dsa_cpu_port_apply(port, index, ds);
+			if (err)
+				return err;
+			continue;
+		}
+
+		err = dsa_user_port_apply(port, index, ds);
+		if (err)
+			continue;
+	}
+
+	return 0;
+}
+
+static void dsa_ds_unapply(struct dsa_switch_tree *dst, struct dsa_switch *ds)
+{
+	struct device_node *port;
+	u32 index;
+
+	for (index = 0; index < DSA_MAX_PORTS; index++) {
+		port = ds->ports[index].dn;
+		if (!port)
+			continue;
+
+		if (dsa_port_is_dsa(port)) {
+			dsa_dsa_port_unapply(port, index, ds);
+			continue;
+		}
+
+		if (dsa_port_is_cpu(port)) {
+			dsa_cpu_port_unapply(port, index, ds);
+			continue;
+		}
+
+		dsa_user_port_unapply(port, index, ds);
+	}
+}
+
+static int dsa_dst_apply(struct dsa_switch_tree *dst)
+{
+	struct dsa_switch *ds;
+	u32 index;
+	int err;
+
+	for (index = 0; index < DSA_MAX_SWITCHES; index++) {
+		ds = dst->ds[index];
+		if (!ds)
+			continue;
+
+		err = dsa_ds_apply(dst, ds);
+		if (err)
+			return err;
+	}
+
+	/* If we use a tagging format that doesn't have an ethertype
+	 * field, make sure that all packets from this point on get
+	 * sent to the tag format's receive function.
+	 */
+	wmb();
+	dst->master_netdev->dsa_ptr = (void *)dst;
+	dst->applied = true;
+
+	return 0;
+}
+
+static void dsa_dst_unapply(struct dsa_switch_tree *dst)
+{
+	struct dsa_switch *ds;
+	u32 index;
+
+	if (!dst->applied)
+		return;
+
+	dst->master_netdev->dsa_ptr = NULL;
+
+	/* If we used a tagging format that doesn't have an ethertype
+	 * field, make sure that all packets from this point get sent
+	 * without the tag and go through the regular receive path.
+	 */
+	wmb();
+
+	for (index = 0; index < DSA_MAX_SWITCHES; index++) {
+		ds = dst->ds[index];
+		if (!ds)
+			continue;
+
+		dsa_ds_unapply(dst, ds);
+	}
+
+	pr_info("DSA: tree %d unapplied\n", dst->tree);
+	dst->applied = false;
+}
+
+static int dsa_cpu_parse(struct device_node *port, u32 index,
+			 struct dsa_switch_tree *dst,
+			 struct dsa_switch *ds)
+{
+	struct net_device *ethernet_dev;
+	struct device_node *ethernet;
+
+	ethernet = of_parse_phandle(port, "ethernet", 0);
+	if (!ethernet)
+		return -EINVAL;
+
+	ethernet_dev = of_find_net_device_by_node(ethernet);
+	if (!ethernet_dev)
+		return -EPROBE_DEFER;
+
+	if (!ds->master_netdev)
+		ds->master_netdev = ethernet_dev;
+
+	if (!dst->master_netdev)
+		dst->master_netdev = ethernet_dev;
+
+	if (dst->cpu_switch == -1) {
+		dst->cpu_switch = ds->index;
+		dst->cpu_port = index;
+	}
+
+	dst->tag_ops = dsa_resolve_tag_protocol(ds->drv->tag_protocol);
+	if (IS_ERR(dst->tag_ops)) {
+		dev_warn(ds->dev, "No tagger for this switch\n");
+		return PTR_ERR(dst->tag_ops);
+	}
+
+	dst->rcv = dst->tag_ops->rcv;
+
+	return 0;
+}
+
+static int dsa_ds_parse(struct dsa_switch_tree *dst, struct dsa_switch *ds)
+{
+	struct device_node *port;
+	u32 index;
+	int err;
+
+	for (index = 0; index < DSA_MAX_PORTS; index++) {
+		port = ds->ports[index].dn;
+		if (!port)
+			continue;
+
+		if (dsa_port_is_cpu(port)) {
+			err = dsa_cpu_parse(port, index, dst, ds);
+			if (err)
+				return err;
+		}
+	}
+
+	pr_info("DSA: switch %d %d parsed\n", dst->tree, ds->index);
+
+	return 0;
+}
+
+static int dsa_dst_parse(struct dsa_switch_tree *dst)
+{
+	struct dsa_switch *ds;
+	u32 index;
+	int err;
+
+	for (index = 0; index < DSA_MAX_SWITCHES; index++) {
+		ds = dst->ds[index];
+		if (!ds)
+			continue;
+
+		err = dsa_ds_parse(dst, ds);
+		if (err)
+			return err;
+	}
+
+	if (!dst->master_netdev) {
+		pr_warn("Tree has no master device\n");
+		return -EINVAL;
+	}
+
+	pr_info("DSA: tree %d parsed\n", dst->tree);
+
+	return 0;
+}
+
+static int dsa_parse_ports_dn(struct device_node *ports, struct dsa_switch *ds)
+{
+	struct device_node *port;
+	int err;
+	u32 reg;
+
+	for_each_available_child_of_node(ports, port) {
+		err = of_property_read_u32(port, "reg", &reg);
+		if (err)
+			return err;
+
+		if (reg >= DSA_MAX_PORTS)
+			return -EINVAL;
+
+		ds->ports[reg].dn = port;
+	}
+
+	return 0;
+}
+
+static int dsa_parse_member(struct device_node *np, u32 *tree, u32 *index)
+{
+	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;
+	}
+
+	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 struct device_node *dsa_get_ports(struct dsa_switch *ds,
+					 struct device_node *np)
+{
+	struct device_node *ports;
+
+	ports = of_get_child_by_name(np, "ports");
+	if (!ports) {
+		dev_err(ds->dev, "no ports child node found\n");
+		return ERR_PTR(-EINVAL);
+	}
+
+	return ports;
+}
+
+static int _dsa_register_switch(struct dsa_switch *ds, struct device_node *np)
+{
+	struct device_node *ports = dsa_get_ports(ds, np);
+	struct dsa_switch_tree *dst;
+	u32 tree, index;
+	int err;
+
+	err = dsa_parse_member(np, &tree, &index);
+	if (err)
+		return err;
+
+	if (IS_ERR(ports))
+		return PTR_ERR(ports);
+
+	err = dsa_parse_ports_dn(ports, 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;
+	}
+
+	ds->dst = dst;
+	ds->index = index;
+	dsa_dst_add_ds(dst, ds, index);
+
+	err = dsa_dst_complete(dst);
+	if (err < 0)
+		goto out_del_dst;
+
+	if (err == 1) {
+		/* Not all switches registered yet */
+		err = 0;
+		goto out;
+	}
+
+	if (dst->applied) {
+		pr_info("DSA: Disjoint trees?\n");
+		return -EINVAL;
+	}
+
+	err = dsa_dst_parse(dst);
+	if (err)
+		goto out_del_dst;
+
+	err = dsa_dst_apply(dst);
+	if (err) {
+		dsa_dst_unapply(dst);
+		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);
+
+	return err;
+}
+
+int dsa_register_switch(struct dsa_switch *ds, struct device_node *np)
+{
+	int err;
+
+	mutex_lock(&dsa2_mutex);
+	err = _dsa_register_switch(ds, np);
+	mutex_unlock(&dsa2_mutex);
+
+	return err;
+}
+EXPORT_SYMBOL_GPL(dsa_register_switch);
+
+void _dsa_unregister_switch(struct dsa_switch *ds)
+{
+	struct dsa_switch_tree *dst = ds->dst;
+
+	dsa_dst_unapply(dst);
+
+	dsa_dst_del_ds(dst, ds, ds->index);
+}
+
+void dsa_unregister_switch(struct dsa_switch *ds)
+{
+	mutex_lock(&dsa2_mutex);
+	_dsa_unregister_switch(ds);
+	mutex_unlock(&dsa2_mutex);
+}
+EXPORT_SYMBOL_GPL(dsa_unregister_switch);