net/dsa/dsa.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * net/dsa/dsa.c - Hardware switch handling
  * Copyright (c) 2008-2009 Marvell Semiconductor
  * Copyright (c) 2013 Florian Fainelli <florian@openwrt.org>
  */

 #include <linux/device.h>
 #include <linux/list.h>
 #include <linux/platform_device.h>
 #include <linux/slab.h>
 #include <linux/module.h>
 #include <linux/notifier.h>
 #include <linux/of.h>
 #include <linux/of_mdio.h>
 #include <linux/of_platform.h>
 #include <linux/of_net.h>
 #include <linux/netdevice.h>
 #include <linux/sysfs.h>
 #include <linux/phy_fixed.h>
 #include <linux/ptp_classify.h>
 #include <linux/etherdevice.h>

 #include "dsa_priv.h"

 static LIST_HEAD(dsa_tag_drivers_list);
 static DEFINE_MUTEX(dsa_tag_drivers_lock);

 static struct sk_buff *dsa_slave_notag_xmit(struct sk_buff *skb,
 					    struct net_device *dev)
 {
 	/* Just return the original SKB */
 	return skb;
 }

 static const struct dsa_device_ops none_ops = {
 	.name	= "none",
 	.proto	= DSA_TAG_PROTO_NONE,
 	.xmit	= dsa_slave_notag_xmit,
 	.rcv	= NULL,
 };

 DSA_TAG_DRIVER(none_ops);

 static void dsa_tag_driver_register(struct dsa_tag_driver *dsa_tag_driver,
 				    struct module *owner)
 {
 	dsa_tag_driver->owner = owner;

 	mutex_lock(&dsa_tag_drivers_lock);
 	list_add_tail(&dsa_tag_driver->list, &dsa_tag_drivers_list);
 	mutex_unlock(&dsa_tag_drivers_lock);
 }

 void dsa_tag_drivers_register(struct dsa_tag_driver *dsa_tag_driver_array[],
 			      unsigned int count, struct module *owner)
 {
 	unsigned int i;

 	for (i = 0; i < count; i++)
 		dsa_tag_driver_register(dsa_tag_driver_array[i], owner);
 }

 static void dsa_tag_driver_unregister(struct dsa_tag_driver *dsa_tag_driver)
 {
 	mutex_lock(&dsa_tag_drivers_lock);
 	list_del(&dsa_tag_driver->list);
 	mutex_unlock(&dsa_tag_drivers_lock);
 }
 EXPORT_SYMBOL_GPL(dsa_tag_drivers_register);

 void dsa_tag_drivers_unregister(struct dsa_tag_driver *dsa_tag_driver_array[],
 				unsigned int count)
 {
 	unsigned int i;

 	for (i = 0; i < count; i++)
 		dsa_tag_driver_unregister(dsa_tag_driver_array[i]);
 }
 EXPORT_SYMBOL_GPL(dsa_tag_drivers_unregister);

 const char *dsa_tag_protocol_to_str(const struct dsa_device_ops *ops)
 {
 	return ops->name;
 };

 const struct dsa_device_ops *dsa_tag_driver_get(int tag_protocol)
 {
 	struct dsa_tag_driver *dsa_tag_driver;
 	const struct dsa_device_ops *ops;
 	char module_name[128];
 	bool found = false;

 	snprintf(module_name, 127, "%s%d", DSA_TAG_DRIVER_ALIAS,
 		 tag_protocol);

 	request_module(module_name);

 	mutex_lock(&dsa_tag_drivers_lock);
 	list_for_each_entry(dsa_tag_driver, &dsa_tag_drivers_list, list) {
 		ops = dsa_tag_driver->ops;
 		if (ops->proto == tag_protocol) {
 			found = true;
 			break;
 		}
 	}

 	if (found) {
 		if (!try_module_get(dsa_tag_driver->owner))
 			ops = ERR_PTR(-ENOPROTOOPT);
 	} else {
 		ops = ERR_PTR(-ENOPROTOOPT);
 	}

 	mutex_unlock(&dsa_tag_drivers_lock);

 	return ops;
 }

 void dsa_tag_driver_put(const struct dsa_device_ops *ops)
 {
 	struct dsa_tag_driver *dsa_tag_driver;

 	mutex_lock(&dsa_tag_drivers_lock);
 	list_for_each_entry(dsa_tag_driver, &dsa_tag_drivers_list, list) {
 		if (dsa_tag_driver->ops == ops) {
 			module_put(dsa_tag_driver->owner);
 			break;
 		}
 	}
 	mutex_unlock(&dsa_tag_drivers_lock);
 }

 static int dev_is_class(struct device *dev, void *class)
 {
 	if (dev->class != NULL && !strcmp(dev->class->name, class))
 		return 1;

 	return 0;
 }

 static struct device *dev_find_class(struct device *parent, char *class)
 {
 	if (dev_is_class(parent, class)) {
 		get_device(parent);
 		return parent;
 	}

 	return device_find_child(parent, class, dev_is_class);
 }

 struct net_device *dsa_dev_to_net_device(struct device *dev)
 {
 	struct device *d;

 	d = dev_find_class(dev, "net");
 	if (d != NULL) {
 		struct net_device *nd;

 		nd = to_net_dev(d);
 		dev_hold(nd);
 		put_device(d);

 		return nd;
 	}

 	return NULL;
 }
 EXPORT_SYMBOL_GPL(dsa_dev_to_net_device);

 /* Determine if we should defer delivery of skb until we have a rx timestamp.
  *
  * Called from dsa_switch_rcv. For now, this will only work if tagging is
  * enabled on the switch. Normally the MAC driver would retrieve the hardware
  * timestamp when it reads the packet out of the hardware. However in a DSA
  * switch, the DSA driver owning the interface to which the packet is
  * delivered is never notified unless we do so here.
  */
 static bool dsa_skb_defer_rx_timestamp(struct dsa_slave_priv *p,
 				       struct sk_buff *skb)
 {
 	struct dsa_switch *ds = p->dp->ds;
 	unsigned int type;

 	if (skb_headroom(skb) < ETH_HLEN)
 		return false;

 	__skb_push(skb, ETH_HLEN);

 	type = ptp_classify_raw(skb);

 	__skb_pull(skb, ETH_HLEN);

 	if (type == PTP_CLASS_NONE)
 		return false;

 	if (likely(ds->ops->port_rxtstamp))
 		return ds->ops->port_rxtstamp(ds, p->dp->index, skb, type);

 	return false;
 }

 static int dsa_switch_rcv(struct sk_buff *skb, struct net_device *dev,
 			  struct packet_type *pt, struct net_device *unused)
 {
 	struct dsa_port *cpu_dp = dev->dsa_ptr;
 	struct sk_buff *nskb = NULL;
 	struct pcpu_sw_netstats *s;
 	struct dsa_slave_priv *p;

 	if (unlikely(!cpu_dp)) {
 		kfree_skb(skb);
 		return 0;
 	}

 	skb = skb_unshare(skb, GFP_ATOMIC);
 	if (!skb)
 		return 0;

 	nskb = cpu_dp->rcv(skb, dev, pt);
 	if (!nskb) {
 		kfree_skb(skb);
 		return 0;
 	}

 	skb = nskb;
 	p = netdev_priv(skb->dev);
 	skb_push(skb, ETH_HLEN);
 	skb->pkt_type = PACKET_HOST;
 	skb->protocol = eth_type_trans(skb, skb->dev);

 	s = this_cpu_ptr(p->stats64);
 	u64_stats_update_begin(&s->syncp);
 	s->rx_packets++;
 	s->rx_bytes += skb->len;
 	u64_stats_update_end(&s->syncp);

 	if (dsa_skb_defer_rx_timestamp(p, skb))
 		return 0;

 	netif_receive_skb(skb);

 	return 0;
 }

 #ifdef CONFIG_PM_SLEEP
 static bool dsa_is_port_initialized(struct dsa_switch *ds, int p)
 {
 	return dsa_is_user_port(ds, p) && ds->ports[p].slave;
 }

 int dsa_switch_suspend(struct dsa_switch *ds)
 {
 	int i, ret = 0;

 	/* Suspend slave network devices */
 	for (i = 0; i < ds->num_ports; i++) {
 		if (!dsa_is_port_initialized(ds, i))
 			continue;

 		ret = dsa_slave_suspend(ds->ports[i].slave);
 		if (ret)
 			return ret;
 	}

 	if (ds->ops->suspend)
 		ret = ds->ops->suspend(ds);

 	return ret;
 }
 EXPORT_SYMBOL_GPL(dsa_switch_suspend);

 int dsa_switch_resume(struct dsa_switch *ds)
 {
 	int i, ret = 0;

 	if (ds->ops->resume)
 		ret = ds->ops->resume(ds);

 	if (ret)
 		return ret;

 	/* Resume slave network devices */
 	for (i = 0; i < ds->num_ports; i++) {
 		if (!dsa_is_port_initialized(ds, i))
 			continue;

 		ret = dsa_slave_resume(ds->ports[i].slave);
 		if (ret)
 			return ret;
 	}

 	return 0;
 }
 EXPORT_SYMBOL_GPL(dsa_switch_resume);
 #endif

 static struct packet_type dsa_pack_type __read_mostly = {
 	.type	= cpu_to_be16(ETH_P_XDSA),
 	.func	= dsa_switch_rcv,
 };

 static struct workqueue_struct *dsa_owq;

 bool dsa_schedule_work(struct work_struct *work)
 {
 	return queue_work(dsa_owq, work);
 }

 static ATOMIC_NOTIFIER_HEAD(dsa_notif_chain);

 int register_dsa_notifier(struct notifier_block *nb)
 {
 	return atomic_notifier_chain_register(&dsa_notif_chain, nb);
 }
 EXPORT_SYMBOL_GPL(register_dsa_notifier);

 int unregister_dsa_notifier(struct notifier_block *nb)
 {
 	return atomic_notifier_chain_unregister(&dsa_notif_chain, nb);
 }
 EXPORT_SYMBOL_GPL(unregister_dsa_notifier);

 int call_dsa_notifiers(unsigned long val, struct net_device *dev,
 		       struct dsa_notifier_info *info)
 {
 	info->dev = dev;
 	return atomic_notifier_call_chain(&dsa_notif_chain, val, info);
 }
 EXPORT_SYMBOL_GPL(call_dsa_notifiers);

 static int __init dsa_init_module(void)
 {
 	int rc;

 	dsa_owq = alloc_ordered_workqueue("dsa_ordered",
 					  WQ_MEM_RECLAIM);
 	if (!dsa_owq)
 		return -ENOMEM;

 	rc = dsa_slave_register_notifier();
 	if (rc)
 		goto register_notifier_fail;

 	dev_add_pack(&dsa_pack_type);

 	dsa_tag_driver_register(&DSA_TAG_DRIVER_NAME(none_ops),
 				THIS_MODULE);

 	return 0;

 register_notifier_fail:
 	destroy_workqueue(dsa_owq);

 	return rc;
 }
 module_init(dsa_init_module);

 static void __exit dsa_cleanup_module(void)
 {
 	dsa_tag_driver_unregister(&DSA_TAG_DRIVER_NAME(none_ops));

 	dsa_slave_unregister_notifier();
 	dev_remove_pack(&dsa_pack_type);
 	destroy_workqueue(dsa_owq);
 }
 module_exit(dsa_cleanup_module);

 MODULE_AUTHOR("Lennert Buytenhek <buytenh@wantstofly.org>");
 MODULE_DESCRIPTION("Driver for Distributed Switch Architecture switch chips");
 MODULE_LICENSE("GPL");
 MODULE_ALIAS("platform:dsa");
	// SPDX-License-Identifier: GPL-2.0-or-later
	/*
	* net/dsa/dsa.c - Hardware switch handling
	* Copyright (c) 2008-2009 Marvell Semiconductor
	* Copyright (c) 2013 Florian Fainelli <florian@openwrt.org>
	*/

	#include <linux/device.h>
	#include <linux/list.h>
	#include <linux/platform_device.h>
	#include <linux/slab.h>
	#include <linux/module.h>
	#include <linux/notifier.h>
	#include <linux/of.h>
	#include <linux/of_mdio.h>
	#include <linux/of_platform.h>
	#include <linux/of_net.h>
	#include <linux/netdevice.h>
	#include <linux/sysfs.h>
	#include <linux/phy_fixed.h>
	#include <linux/ptp_classify.h>
	#include <linux/etherdevice.h>

	#include "dsa_priv.h"

	static LIST_HEAD(dsa_tag_drivers_list);
	static DEFINE_MUTEX(dsa_tag_drivers_lock);

	static struct sk_buff dsa_slave_notag_xmit(struct sk_buff skb,
	struct net_device *dev)
	{
	/* Just return the original SKB */
	return skb;
	}

	static const struct dsa_device_ops none_ops = {
	.name = "none",
	.proto = DSA_TAG_PROTO_NONE,
	.xmit = dsa_slave_notag_xmit,
	.rcv = NULL,
	};

	DSA_TAG_DRIVER(none_ops);

	static void dsa_tag_driver_register(struct dsa_tag_driver *dsa_tag_driver,
	struct module *owner)
	{
	dsa_tag_driver->owner = owner;

	mutex_lock(&dsa_tag_drivers_lock);
	list_add_tail(&dsa_tag_driver->list, &dsa_tag_drivers_list);
	mutex_unlock(&dsa_tag_drivers_lock);
	}

	void dsa_tag_drivers_register(struct dsa_tag_driver *dsa_tag_driver_array[],
	unsigned int count, struct module *owner)
	{
	unsigned int i;

	for (i = 0; i < count; i++)
	dsa_tag_driver_register(dsa_tag_driver_array[i], owner);
	}

	static void dsa_tag_driver_unregister(struct dsa_tag_driver *dsa_tag_driver)
	{
	mutex_lock(&dsa_tag_drivers_lock);
	list_del(&dsa_tag_driver->list);
	mutex_unlock(&dsa_tag_drivers_lock);
	}
	EXPORT_SYMBOL_GPL(dsa_tag_drivers_register);

	void dsa_tag_drivers_unregister(struct dsa_tag_driver *dsa_tag_driver_array[],
	unsigned int count)
	{
	unsigned int i;

	for (i = 0; i < count; i++)
	dsa_tag_driver_unregister(dsa_tag_driver_array[i]);
	}
	EXPORT_SYMBOL_GPL(dsa_tag_drivers_unregister);

	const char dsa_tag_protocol_to_str(const struct dsa_device_ops ops)
	{
	return ops->name;
	};

	const struct dsa_device_ops *dsa_tag_driver_get(int tag_protocol)
	{
	struct dsa_tag_driver *dsa_tag_driver;
	const struct dsa_device_ops *ops;
	char module_name[128];
	bool found = false;

	snprintf(module_name, 127, "%s%d", DSA_TAG_DRIVER_ALIAS,
	tag_protocol);

	request_module(module_name);

	mutex_lock(&dsa_tag_drivers_lock);
	list_for_each_entry(dsa_tag_driver, &dsa_tag_drivers_list, list) {
	ops = dsa_tag_driver->ops;
	if (ops->proto == tag_protocol) {
	found = true;
	break;
	}
	}

	if (found) {
	if (!try_module_get(dsa_tag_driver->owner))
	ops = ERR_PTR(-ENOPROTOOPT);
	} else {
	ops = ERR_PTR(-ENOPROTOOPT);
	}

	mutex_unlock(&dsa_tag_drivers_lock);

	return ops;
	}

	void dsa_tag_driver_put(const struct dsa_device_ops *ops)
	{
	struct dsa_tag_driver *dsa_tag_driver;

	mutex_lock(&dsa_tag_drivers_lock);
	list_for_each_entry(dsa_tag_driver, &dsa_tag_drivers_list, list) {
	if (dsa_tag_driver->ops == ops) {
	module_put(dsa_tag_driver->owner);
	break;
	}
	}
	mutex_unlock(&dsa_tag_drivers_lock);
	}

	static int dev_is_class(struct device dev, void class)
	{
	if (dev->class != NULL && !strcmp(dev->class->name, class))
	return 1;

	return 0;
	}

	static struct device dev_find_class(struct device parent, char *class)
	{
	if (dev_is_class(parent, class)) {
	get_device(parent);
	return parent;
	}

	return device_find_child(parent, class, dev_is_class);
	}

	struct net_device dsa_dev_to_net_device(struct device dev)
	{
	struct device *d;

	d = dev_find_class(dev, "net");
	if (d != NULL) {
	struct net_device *nd;

	nd = to_net_dev(d);
	dev_hold(nd);
	put_device(d);

	return nd;
	}

	return NULL;
	}
	EXPORT_SYMBOL_GPL(dsa_dev_to_net_device);

	/* Determine if we should defer delivery of skb until we have a rx timestamp.
	*
	* Called from dsa_switch_rcv. For now, this will only work if tagging is
	* enabled on the switch. Normally the MAC driver would retrieve the hardware
	* timestamp when it reads the packet out of the hardware. However in a DSA
	* switch, the DSA driver owning the interface to which the packet is
	* delivered is never notified unless we do so here.
	*/
	static bool dsa_skb_defer_rx_timestamp(struct dsa_slave_priv *p,
	struct sk_buff *skb)
	{
	struct dsa_switch *ds = p->dp->ds;
	unsigned int type;

	if (skb_headroom(skb) < ETH_HLEN)
	return false;

	__skb_push(skb, ETH_HLEN);

	type = ptp_classify_raw(skb);

	__skb_pull(skb, ETH_HLEN);

	if (type == PTP_CLASS_NONE)
	return false;

	if (likely(ds->ops->port_rxtstamp))
	return ds->ops->port_rxtstamp(ds, p->dp->index, skb, type);

	return false;
	}

	static int dsa_switch_rcv(struct sk_buff skb, struct net_device dev,
	struct packet_type pt, struct net_device unused)
	{
	struct dsa_port *cpu_dp = dev->dsa_ptr;
	struct sk_buff *nskb = NULL;
	struct pcpu_sw_netstats *s;
	struct dsa_slave_priv *p;

	if (unlikely(!cpu_dp)) {
	kfree_skb(skb);
	return 0;
	}

	skb = skb_unshare(skb, GFP_ATOMIC);
	if (!skb)
	return 0;

	nskb = cpu_dp->rcv(skb, dev, pt);
	if (!nskb) {
	kfree_skb(skb);
	return 0;
	}

	skb = nskb;
	p = netdev_priv(skb->dev);
	skb_push(skb, ETH_HLEN);
	skb->pkt_type = PACKET_HOST;
	skb->protocol = eth_type_trans(skb, skb->dev);

	s = this_cpu_ptr(p->stats64);
	u64_stats_update_begin(&s->syncp);
	s->rx_packets++;
	s->rx_bytes += skb->len;
	u64_stats_update_end(&s->syncp);

	if (dsa_skb_defer_rx_timestamp(p, skb))
	return 0;

	netif_receive_skb(skb);

	return 0;
	}

	#ifdef CONFIG_PM_SLEEP
	static bool dsa_is_port_initialized(struct dsa_switch *ds, int p)
	{
	return dsa_is_user_port(ds, p) && ds->ports[p].slave;
	}

	int dsa_switch_suspend(struct dsa_switch *ds)
	{
	int i, ret = 0;

	/* Suspend slave network devices */
	for (i = 0; i < ds->num_ports; i++) {
	if (!dsa_is_port_initialized(ds, i))
	continue;

	ret = dsa_slave_suspend(ds->ports[i].slave);
	if (ret)
	return ret;
	}

	if (ds->ops->suspend)
	ret = ds->ops->suspend(ds);

	return ret;
	}
	EXPORT_SYMBOL_GPL(dsa_switch_suspend);

	int dsa_switch_resume(struct dsa_switch *ds)
	{
	int i, ret = 0;

	if (ds->ops->resume)
	ret = ds->ops->resume(ds);

	if (ret)
	return ret;

	/* Resume slave network devices */
	for (i = 0; i < ds->num_ports; i++) {
	if (!dsa_is_port_initialized(ds, i))
	continue;

	ret = dsa_slave_resume(ds->ports[i].slave);
	if (ret)
	return ret;
	}

	return 0;
	}
	EXPORT_SYMBOL_GPL(dsa_switch_resume);
	#endif

	static struct packet_type dsa_pack_type __read_mostly = {
	.type = cpu_to_be16(ETH_P_XDSA),
	.func = dsa_switch_rcv,
	};

	static struct workqueue_struct *dsa_owq;

	bool dsa_schedule_work(struct work_struct *work)
	{
	return queue_work(dsa_owq, work);
	}

	static ATOMIC_NOTIFIER_HEAD(dsa_notif_chain);

	int register_dsa_notifier(struct notifier_block *nb)
	{
	return atomic_notifier_chain_register(&dsa_notif_chain, nb);
	}
	EXPORT_SYMBOL_GPL(register_dsa_notifier);

	int unregister_dsa_notifier(struct notifier_block *nb)
	{
	return atomic_notifier_chain_unregister(&dsa_notif_chain, nb);
	}
	EXPORT_SYMBOL_GPL(unregister_dsa_notifier);

	int call_dsa_notifiers(unsigned long val, struct net_device *dev,
	struct dsa_notifier_info *info)
	{
	info->dev = dev;
	return atomic_notifier_call_chain(&dsa_notif_chain, val, info);
	}
	EXPORT_SYMBOL_GPL(call_dsa_notifiers);

	static int __init dsa_init_module(void)
	{
	int rc;

	dsa_owq = alloc_ordered_workqueue("dsa_ordered",
	WQ_MEM_RECLAIM);
	if (!dsa_owq)
	return -ENOMEM;

	rc = dsa_slave_register_notifier();
	if (rc)
	goto register_notifier_fail;

	dev_add_pack(&dsa_pack_type);

	dsa_tag_driver_register(&DSA_TAG_DRIVER_NAME(none_ops),
	THIS_MODULE);

	return 0;

	register_notifier_fail:
	destroy_workqueue(dsa_owq);

	return rc;
	}
	module_init(dsa_init_module);

	static void __exit dsa_cleanup_module(void)
	{
	dsa_tag_driver_unregister(&DSA_TAG_DRIVER_NAME(none_ops));

	dsa_slave_unregister_notifier();
	dev_remove_pack(&dsa_pack_type);
	destroy_workqueue(dsa_owq);
	}
	module_exit(dsa_cleanup_module);

	MODULE_AUTHOR("Lennert Buytenhek <buytenh@wantstofly.org>");
	MODULE_DESCRIPTION("Driver for Distributed Switch Architecture switch chips");
	MODULE_LICENSE("GPL");
	MODULE_ALIAS("platform:dsa");