--- /dev/null
+/*
+ * 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", ®);
+               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);