Merge branch 'dsa-new-binding'

Andrew Lunn says:

====================
New DSA bind, switches as devices

The interesting patches here are the last three. They implement a new
binding for DSA, which removes a few limitations of the current DSA
binding. In particular, it allows switches to be true Linux devices.
These devices can be on any type of bus, unlike the old DSA binding
which assumes MDIO. See the commit log for more details. The second to
last patch modifies an existing boards device tree to use the new
binding, giving a good example of how switches can be true MDIO
devices. The last patch documents the new binding.

Thanks go to Florian and Vivien for reviewing, testing and bug fixing
these patches.

Tested-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Tested-by: Florian Fainelli <f.fainelli@gmail.com>

Since V1:

* Add lots of reviewed-by's
* Fix rtable comment
* dsa2: Clear cpu port mask in dsa_cpu_port_unapply()
* dsa2: Only set dsa_port_mask when port successfully configured
* dsa: clear {dsa|cpu}_port_mask on destroy

Since RFC:

* Split the mv88e6xxx MDIO refactor into a rename patch and a refactor
  patch.
* Extend commit message with comment about wrong of_node_put()
* Fix destroy of cpu and dsa ports.
* Rename _DSA_TAG_LAST to DSA_TAG_LAST and add a comment.
====================

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);