// SPDX-License-Identifier: GPL-2.0-or-later

  /*
   * Handling of a master device, switching frames via its switch fabric CPU port
   *
   * Copyright (c) 2017 Savoir-faire Linux Inc.
   *	Vivien Didelot <vivien.didelot@savoirfairelinux.com>

   */
  
  #include "dsa_priv.h"

  static int dsa_master_get_regs_len(struct net_device *dev)
  {
  	struct dsa_port *cpu_dp = dev->dsa_ptr;
  	const struct ethtool_ops *ops = cpu_dp->orig_ethtool_ops;
  	struct dsa_switch *ds = cpu_dp->ds;
  	int port = cpu_dp->index;
  	int ret = 0;
  	int len;
  
  	if (ops->get_regs_len) {
  		len = ops->get_regs_len(dev);
  		if (len < 0)
  			return len;
  		ret += len;
  	}
  
  	ret += sizeof(struct ethtool_drvinfo);
  	ret += sizeof(struct ethtool_regs);
  
  	if (ds->ops->get_regs_len) {
  		len = ds->ops->get_regs_len(ds, port);
  		if (len < 0)
  			return len;
  		ret += len;
  	}
  
  	return ret;
  }
  
  static void dsa_master_get_regs(struct net_device *dev,
  				struct ethtool_regs *regs, void *data)
  {
  	struct dsa_port *cpu_dp = dev->dsa_ptr;
  	const struct ethtool_ops *ops = cpu_dp->orig_ethtool_ops;
  	struct dsa_switch *ds = cpu_dp->ds;
  	struct ethtool_drvinfo *cpu_info;
  	struct ethtool_regs *cpu_regs;
  	int port = cpu_dp->index;
  	int len;
  
  	if (ops->get_regs_len && ops->get_regs) {
  		len = ops->get_regs_len(dev);
  		if (len < 0)
  			return;
  		regs->len = len;
  		ops->get_regs(dev, regs, data);
  		data += regs->len;
  	}
  
  	cpu_info = (struct ethtool_drvinfo *)data;
  	strlcpy(cpu_info->driver, "dsa", sizeof(cpu_info->driver));
  	data += sizeof(*cpu_info);
  	cpu_regs = (struct ethtool_regs *)data;
  	data += sizeof(*cpu_regs);
  
  	if (ds->ops->get_regs_len && ds->ops->get_regs) {
  		len = ds->ops->get_regs_len(ds, port);
  		if (len < 0)
  			return;
  		cpu_regs->len = len;
  		ds->ops->get_regs(ds, port, cpu_regs, data);
  	}
  }

  static void dsa_master_get_ethtool_stats(struct net_device *dev,
  					 struct ethtool_stats *stats,
  					 uint64_t *data)
  {

  	struct dsa_port *cpu_dp = dev->dsa_ptr;

  	const struct ethtool_ops *ops = cpu_dp->orig_ethtool_ops;
  	struct dsa_switch *ds = cpu_dp->ds;
  	int port = cpu_dp->index;

  	int count = 0;

  	if (ops->get_sset_count && ops->get_ethtool_stats) {

  		count = ops->get_sset_count(dev, ETH_SS_STATS);
  		ops->get_ethtool_stats(dev, stats, data);
  	}
  
  	if (ds->ops->get_ethtool_stats)

  		ds->ops->get_ethtool_stats(ds, port, data + count);

  }

  static void dsa_master_get_ethtool_phy_stats(struct net_device *dev,
  					     struct ethtool_stats *stats,
  					     uint64_t *data)
  {
  	struct dsa_port *cpu_dp = dev->dsa_ptr;
  	const struct ethtool_ops *ops = cpu_dp->orig_ethtool_ops;
  	struct dsa_switch *ds = cpu_dp->ds;
  	int port = cpu_dp->index;
  	int count = 0;
  
  	if (dev->phydev && !ops->get_ethtool_phy_stats) {
  		count = phy_ethtool_get_sset_count(dev->phydev);
  		if (count >= 0)
  			phy_ethtool_get_stats(dev->phydev, stats, data);
  	} else if (ops->get_sset_count && ops->get_ethtool_phy_stats) {
  		count = ops->get_sset_count(dev, ETH_SS_PHY_STATS);
  		ops->get_ethtool_phy_stats(dev, stats, data);
  	}
  
  	if (count < 0)
  		count = 0;
  
  	if (ds->ops->get_ethtool_phy_stats)
  		ds->ops->get_ethtool_phy_stats(ds, port, data + count);
  }

  static int dsa_master_get_sset_count(struct net_device *dev, int sset)
  {

  	struct dsa_port *cpu_dp = dev->dsa_ptr;

  	const struct ethtool_ops *ops = cpu_dp->orig_ethtool_ops;
  	struct dsa_switch *ds = cpu_dp->ds;

  	int count = 0;

  	if (sset == ETH_SS_PHY_STATS && dev->phydev &&
  	    !ops->get_ethtool_phy_stats)
  		count = phy_ethtool_get_sset_count(dev->phydev);
  	else if (ops->get_sset_count)

  		count = ops->get_sset_count(dev, sset);

  
  	if (count < 0)
  		count = 0;

  	if (ds->ops->get_sset_count)
  		count += ds->ops->get_sset_count(ds, cpu_dp->index, sset);

  
  	return count;
  }
  
  static void dsa_master_get_strings(struct net_device *dev, uint32_t stringset,
  				   uint8_t *data)
  {

  	struct dsa_port *cpu_dp = dev->dsa_ptr;

  	const struct ethtool_ops *ops = cpu_dp->orig_ethtool_ops;
  	struct dsa_switch *ds = cpu_dp->ds;
  	int port = cpu_dp->index;

  	int len = ETH_GSTRING_LEN;
  	int mcount = 0, count;
  	unsigned int i;
  	uint8_t pfx[4];
  	uint8_t *ndata;

  	snprintf(pfx, sizeof(pfx), "p%.2d", port);

  	/* We do not want to be NULL-terminated, since this is a prefix */
  	pfx[sizeof(pfx) - 1] = '_';

  	if (stringset == ETH_SS_PHY_STATS && dev->phydev &&
  	    !ops->get_ethtool_phy_stats) {
  		mcount = phy_ethtool_get_sset_count(dev->phydev);
  		if (mcount < 0)
  			mcount = 0;
  		else
  			phy_ethtool_get_strings(dev->phydev, data);
  	} else if (ops->get_sset_count && ops->get_strings) {

  		mcount = ops->get_sset_count(dev, stringset);
  		if (mcount < 0)
  			mcount = 0;

  		ops->get_strings(dev, stringset, data);
  	}

  	if (ds->ops->get_strings) {

  		ndata = data + mcount * len;
  		/* This function copies ETH_GSTRINGS_LEN bytes, we will mangle
  		 * the output after to prepend our CPU port prefix we
  		 * constructed earlier
  		 */

  		ds->ops->get_strings(ds, port, stringset, ndata);
  		count = ds->ops->get_sset_count(ds, port, stringset);

  		for (i = 0; i < count; i++) {
  			memmove(ndata + (i * len + sizeof(pfx)),
  				ndata + i * len, len - sizeof(pfx));
  			memcpy(ndata + i * len, pfx, sizeof(pfx));
  		}
  	}
  }

  static int dsa_master_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
  {
  	struct dsa_port *cpu_dp = dev->dsa_ptr;
  	struct dsa_switch *ds = cpu_dp->ds;
  	struct dsa_switch_tree *dst;
  	int err = -EOPNOTSUPP;
  	struct dsa_port *dp;
  
  	dst = ds->dst;
  
  	switch (cmd) {
  	case SIOCGHWTSTAMP:
  	case SIOCSHWTSTAMP:
  		/* Deny PTP operations on master if there is at least one
  		 * switch in the tree that is PTP capable.
  		 */
  		list_for_each_entry(dp, &dst->ports, list)
  			if (dp->ds->ops->port_hwtstamp_get ||
  			    dp->ds->ops->port_hwtstamp_set)
  				return -EBUSY;
  		break;
  	}

  	if (dev->netdev_ops->ndo_do_ioctl)
  		err = dev->netdev_ops->ndo_do_ioctl(dev, ifr, cmd);

  
  	return err;
  }

  static const struct dsa_netdevice_ops dsa_netdev_ops = {
  	.ndo_do_ioctl = dsa_master_ioctl,

  };

  static int dsa_master_ethtool_setup(struct net_device *dev)

  {

  	struct dsa_port *cpu_dp = dev->dsa_ptr;

  	struct dsa_switch *ds = cpu_dp->ds;

  	struct ethtool_ops *ops;
  
  	ops = devm_kzalloc(ds->dev, sizeof(*ops), GFP_KERNEL);
  	if (!ops)
  		return -ENOMEM;

  	cpu_dp->orig_ethtool_ops = dev->ethtool_ops;
  	if (cpu_dp->orig_ethtool_ops)
  		memcpy(ops, cpu_dp->orig_ethtool_ops, sizeof(*ops));

  	ops->get_regs_len = dsa_master_get_regs_len;
  	ops->get_regs = dsa_master_get_regs;

  	ops->get_sset_count = dsa_master_get_sset_count;
  	ops->get_ethtool_stats = dsa_master_get_ethtool_stats;
  	ops->get_strings = dsa_master_get_strings;

  	ops->get_ethtool_phy_stats = dsa_master_get_ethtool_phy_stats;

  
  	dev->ethtool_ops = ops;
  
  	return 0;
  }

  static void dsa_master_ethtool_teardown(struct net_device *dev)

  {

  	struct dsa_port *cpu_dp = dev->dsa_ptr;

  	dev->ethtool_ops = cpu_dp->orig_ethtool_ops;
  	cpu_dp->orig_ethtool_ops = NULL;

  }

  static void dsa_netdev_ops_set(struct net_device *dev,
  			       const struct dsa_netdevice_ops *ops)

  {

  	dev->dsa_ptr->netdev_ops = ops;

  }

  static void dsa_master_set_promiscuity(struct net_device *dev, int inc)
  {
  	const struct dsa_device_ops *ops = dev->dsa_ptr->tag_ops;
  
  	if (!ops->promisc_on_master)
  		return;
  
  	rtnl_lock();
  	dev_set_promiscuity(dev, inc);
  	rtnl_unlock();
  }

  static ssize_t tagging_show(struct device *d, struct device_attribute *attr,
  			    char *buf)
  {
  	struct net_device *dev = to_net_dev(d);
  	struct dsa_port *cpu_dp = dev->dsa_ptr;
  
  	return sprintf(buf, "%s
  ",
  		       dsa_tag_protocol_to_str(cpu_dp->tag_ops));
  }
  static DEVICE_ATTR_RO(tagging);
  
  static struct attribute *dsa_slave_attrs[] = {
  	&dev_attr_tagging.attr,
  	NULL
  };
  
  static const struct attribute_group dsa_group = {
  	.name	= "dsa",
  	.attrs	= dsa_slave_attrs,
  };

  static void dsa_master_reset_mtu(struct net_device *dev)
  {
  	int err;
  
  	rtnl_lock();
  	err = dev_set_mtu(dev, ETH_DATA_LEN);
  	if (err)
  		netdev_dbg(dev,
  			   "Unable to reset MTU to exclude DSA overheads
  ");
  	rtnl_unlock();
  }

  static struct lock_class_key dsa_master_addr_list_lock_key;

  int dsa_master_setup(struct net_device *dev, struct dsa_port *cpu_dp)
  {

  	int ret;

  	rtnl_lock();
  	ret = dev_set_mtu(dev, ETH_DATA_LEN + cpu_dp->tag_ops->overhead);
  	rtnl_unlock();
  	if (ret)
  		netdev_warn(dev, "error %d setting MTU to include DSA overhead
  ",
  			    ret);

  	/* 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();
  
  	dev->dsa_ptr = cpu_dp;

  	lockdep_set_class(&dev->addr_list_lock,
  			  &dsa_master_addr_list_lock_key);

  
  	dsa_master_set_promiscuity(dev, 1);

  	ret = dsa_master_ethtool_setup(dev);
  	if (ret)

  		goto out_err_reset_promisc;

  	dsa_netdev_ops_set(dev, &dsa_netdev_ops);

  	ret = sysfs_create_group(&dev->dev.kobj, &dsa_group);
  	if (ret)

  		goto out_err_ndo_teardown;
  
  	return ret;

  out_err_ndo_teardown:

  	dsa_netdev_ops_set(dev, NULL);

  	dsa_master_ethtool_teardown(dev);

  out_err_reset_promisc:
  	dsa_master_set_promiscuity(dev, -1);

  	return ret;

  }
  
  void dsa_master_teardown(struct net_device *dev)
  {

  	sysfs_remove_group(&dev->dev.kobj, &dsa_group);

  	dsa_netdev_ops_set(dev, NULL);

  	dsa_master_ethtool_teardown(dev);

  	dsa_master_reset_mtu(dev);

  	dsa_master_set_promiscuity(dev, -1);

  
  	dev->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();
  }