[linux-2.6-block.git] / net / dsa / master.c

// 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_get_phys_port_name(struct net_device *dev,
					 char *name, size_t len)
{
	struct dsa_port *cpu_dp = dev->dsa_ptr;

	if (snprintf(name, len, "p%d", cpu_dp->index) >= len)
		return -EINVAL;

	return 0;
}

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 int dsa_master_ndo_setup(struct net_device *dev)
{
	struct dsa_port *cpu_dp = dev->dsa_ptr;
	struct dsa_switch *ds = cpu_dp->ds;
	struct net_device_ops *ops;

	if (dev->netdev_ops->ndo_get_phys_port_name)
		return 0;

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

	cpu_dp->orig_ndo_ops = dev->netdev_ops;
	if (cpu_dp->orig_ndo_ops)
		memcpy(ops, cpu_dp->orig_ndo_ops, sizeof(*ops));

	ops->ndo_get_phys_port_name = dsa_master_get_phys_port_name;

	dev->netdev_ops  = ops;

	return 0;
}

static void dsa_master_ndo_teardown(struct net_device *dev)
{
	struct dsa_port *cpu_dp = dev->dsa_ptr;

	dev->netdev_ops = cpu_dp->orig_ndo_ops;
	cpu_dp->orig_ndo_ops = NULL;
}

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\n",
		       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_set_mtu(struct net_device *dev, struct dsa_port *cpu_dp)
{
	unsigned int mtu = ETH_DATA_LEN + cpu_dp->tag_ops->overhead;
	int err;

	rtnl_lock();
	if (mtu <= dev->max_mtu) {
		err = dev_set_mtu(dev, mtu);
		if (err)
			netdev_dbg(dev, "Unable to set MTU to include for DSA overheads\n");
	}
	rtnl_unlock();
}

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\n");
	rtnl_unlock();
}

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

	dsa_master_set_mtu(dev,  cpu_dp);

	/* 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;
	ret = dsa_master_ethtool_setup(dev);
	if (ret)
		return ret;

	ret = dsa_master_ndo_setup(dev);
	if (ret)
		goto out_err_ethtool_teardown;

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

	return ret;

out_err_ndo_teardown:
	dsa_master_ndo_teardown(dev);
out_err_ethtool_teardown:
	dsa_master_ethtool_teardown(dev);
	return ret;
}

void dsa_master_teardown(struct net_device *dev)
{
	sysfs_remove_group(&dev->dev.kobj, &dsa_group);
	dsa_master_ndo_teardown(dev);
	dsa_master_ethtool_teardown(dev);
	dsa_master_reset_mtu(dev);

	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();
}
Commit	Line	Data
2874c5fd	1	// SPDX-License-Identifier: GPL-2.0-or-later
f2f23566 VD	2	/*
	3	* Handling of a master device, switching frames via its switch fabric CPU port
	4	*
	5	* Copyright (c) 2017 Savoir-faire Linux Inc.
	6	* Vivien Didelot <vivien.didelot@savoirfairelinux.com>
f2f23566 VD	7	*/
	8
	9	#include "dsa_priv.h"
	10
48e23311 VD	11	static int dsa_master_get_regs_len(struct net_device *dev)
	12	{
	13	struct dsa_port *cpu_dp = dev->dsa_ptr;
	14	const struct ethtool_ops *ops = cpu_dp->orig_ethtool_ops;
	15	struct dsa_switch *ds = cpu_dp->ds;
	16	int port = cpu_dp->index;
	17	int ret = 0;
	18	int len;
	19
	20	if (ops->get_regs_len) {
	21	len = ops->get_regs_len(dev);
	22	if (len < 0)
	23	return len;
	24	ret += len;
	25	}
	26
	27	ret += sizeof(struct ethtool_drvinfo);
	28	ret += sizeof(struct ethtool_regs);
	29
	30	if (ds->ops->get_regs_len) {
	31	len = ds->ops->get_regs_len(ds, port);
	32	if (len < 0)
	33	return len;
	34	ret += len;
	35	}
	36
	37	return ret;
	38	}
	39
	40	static void dsa_master_get_regs(struct net_device *dev,
	41	struct ethtool_regs regs, void data)
	42	{
	43	struct dsa_port *cpu_dp = dev->dsa_ptr;
	44	const struct ethtool_ops *ops = cpu_dp->orig_ethtool_ops;
	45	struct dsa_switch *ds = cpu_dp->ds;
	46	struct ethtool_drvinfo *cpu_info;
	47	struct ethtool_regs *cpu_regs;
	48	int port = cpu_dp->index;
	49	int len;
	50
	51	if (ops->get_regs_len && ops->get_regs) {
	52	len = ops->get_regs_len(dev);
	53	if (len < 0)
	54	return;
	55	regs->len = len;
	56	ops->get_regs(dev, regs, data);
	57	data += regs->len;
	58	}
	59
	60	cpu_info = (struct ethtool_drvinfo *)data;
	61	strlcpy(cpu_info->driver, "dsa", sizeof(cpu_info->driver));
	62	data += sizeof(*cpu_info);
	63	cpu_regs = (struct ethtool_regs *)data;
	64	data += sizeof(*cpu_regs);
	65
	66	if (ds->ops->get_regs_len && ds->ops->get_regs) {
	67	len = ds->ops->get_regs_len(ds, port);
	68	if (len < 0)
	69	return;
	70	cpu_regs->len = len;
	71	ds->ops->get_regs(ds, port, cpu_regs, data);
	72	}
	73	}
	74
f2f23566 VD	75	static void dsa_master_get_ethtool_stats(struct net_device *dev,
	76	struct ethtool_stats *stats,
	77	uint64_t *data)
	78	{
2f657a60	79	struct dsa_port *cpu_dp = dev->dsa_ptr;
7ec764ee VD	80	const struct ethtool_ops *ops = cpu_dp->orig_ethtool_ops;
	81	struct dsa_switch *ds = cpu_dp->ds;
	82	int port = cpu_dp->index;
f2f23566 VD	83	int count = 0;
f2f23566 VD	84
1d1e79f1	85	if (ops->get_sset_count && ops->get_ethtool_stats) {
f2f23566 VD	86	count = ops->get_sset_count(dev, ETH_SS_STATS);
	87	ops->get_ethtool_stats(dev, stats, data);
	88	}
	89
	90	if (ds->ops->get_ethtool_stats)
7ec764ee	91	ds->ops->get_ethtool_stats(ds, port, data + count);
f2f23566 VD	92	}
f2f23566 VD	93
cf963573 FF	94	static void dsa_master_get_ethtool_phy_stats(struct net_device *dev,
	95	struct ethtool_stats *stats,
	96	uint64_t *data)
	97	{
	98	struct dsa_port *cpu_dp = dev->dsa_ptr;
	99	const struct ethtool_ops *ops = cpu_dp->orig_ethtool_ops;
	100	struct dsa_switch *ds = cpu_dp->ds;
	101	int port = cpu_dp->index;
	102	int count = 0;
	103
	104	if (dev->phydev && !ops->get_ethtool_phy_stats) {
	105	count = phy_ethtool_get_sset_count(dev->phydev);
	106	if (count >= 0)
	107	phy_ethtool_get_stats(dev->phydev, stats, data);
	108	} else if (ops->get_sset_count && ops->get_ethtool_phy_stats) {
	109	count = ops->get_sset_count(dev, ETH_SS_PHY_STATS);
	110	ops->get_ethtool_phy_stats(dev, stats, data);
	111	}
	112
	113	if (count < 0)
	114	count = 0;
	115
	116	if (ds->ops->get_ethtool_phy_stats)
	117	ds->ops->get_ethtool_phy_stats(ds, port, data + count);
	118	}
	119
f2f23566 VD	120	static int dsa_master_get_sset_count(struct net_device *dev, int sset)
f2f23566 VD	121	{
2f657a60	122	struct dsa_port *cpu_dp = dev->dsa_ptr;
7ec764ee VD	123	const struct ethtool_ops *ops = cpu_dp->orig_ethtool_ops;
7ec764ee VD	124	struct dsa_switch *ds = cpu_dp->ds;
f2f23566 VD	125	int count = 0;
f2f23566 VD	126
cf963573 FF	127	if (sset == ETH_SS_PHY_STATS && dev->phydev &&
	128	!ops->get_ethtool_phy_stats)
	129	count = phy_ethtool_get_sset_count(dev->phydev);
	130	else if (ops->get_sset_count)
89f09048	131	count = ops->get_sset_count(dev, sset);
cf963573 FF	132
	133	if (count < 0)
	134	count = 0;
f2f23566	135
89f09048 FF	136	if (ds->ops->get_sset_count)
89f09048 FF	137	count += ds->ops->get_sset_count(ds, cpu_dp->index, sset);
f2f23566 VD	138
	139	return count;
	140	}
	141
	142	static void dsa_master_get_strings(struct net_device *dev, uint32_t stringset,
	143	uint8_t *data)
	144	{
2f657a60	145	struct dsa_port *cpu_dp = dev->dsa_ptr;
7ec764ee VD	146	const struct ethtool_ops *ops = cpu_dp->orig_ethtool_ops;
	147	struct dsa_switch *ds = cpu_dp->ds;
	148	int port = cpu_dp->index;
f2f23566 VD	149	int len = ETH_GSTRING_LEN;
	150	int mcount = 0, count;
	151	unsigned int i;
	152	uint8_t pfx[4];
	153	uint8_t *ndata;
	154
7ec764ee	155	snprintf(pfx, sizeof(pfx), "p%.2d", port);
f2f23566 VD	156	/* We do not want to be NULL-terminated, since this is a prefix */
	157	pfx[sizeof(pfx) - 1] = '_';
	158
cf963573 FF	159	if (stringset == ETH_SS_PHY_STATS && dev->phydev &&
	160	!ops->get_ethtool_phy_stats) {
	161	mcount = phy_ethtool_get_sset_count(dev->phydev);
	162	if (mcount < 0)
	163	mcount = 0;
	164	else
	165	phy_ethtool_get_strings(dev->phydev, data);
	166	} else if (ops->get_sset_count && ops->get_strings) {
89f09048 FF	167	mcount = ops->get_sset_count(dev, stringset);
	168	if (mcount < 0)
	169	mcount = 0;
f2f23566 VD	170	ops->get_strings(dev, stringset, data);
	171	}
	172
89f09048	173	if (ds->ops->get_strings) {
f2f23566 VD	174	ndata = data + mcount * len;
	175	/* This function copies ETH_GSTRINGS_LEN bytes, we will mangle
	176	* the output after to prepend our CPU port prefix we
	177	* constructed earlier
	178	*/
89f09048 FF	179	ds->ops->get_strings(ds, port, stringset, ndata);
89f09048 FF	180	count = ds->ops->get_sset_count(ds, port, stringset);
f2f23566 VD	181	for (i = 0; i < count; i++) {
	182	memmove(ndata + (i * len + sizeof(pfx)),
	183	ndata + i * len, len - sizeof(pfx));
	184	memcpy(ndata + i * len, pfx, sizeof(pfx));
	185	}
	186	}
	187	}
	188
da7b9e9b FF	189	static int dsa_master_get_phys_port_name(struct net_device *dev,
	190	char *name, size_t len)
	191	{
	192	struct dsa_port *cpu_dp = dev->dsa_ptr;
	193
	194	if (snprintf(name, len, "p%d", cpu_dp->index) >= len)
	195	return -EINVAL;
	196
	197	return 0;
	198	}
	199
17a22fcf	200	static int dsa_master_ethtool_setup(struct net_device *dev)
f2f23566	201	{
2f657a60	202	struct dsa_port *cpu_dp = dev->dsa_ptr;
7ec764ee	203	struct dsa_switch *ds = cpu_dp->ds;
f2f23566 VD	204	struct ethtool_ops *ops;
	205
	206	ops = devm_kzalloc(ds->dev, sizeof(*ops), GFP_KERNEL);
	207	if (!ops)
	208	return -ENOMEM;
	209
7ec764ee VD	210	cpu_dp->orig_ethtool_ops = dev->ethtool_ops;
	211	if (cpu_dp->orig_ethtool_ops)
	212	memcpy(ops, cpu_dp->orig_ethtool_ops, sizeof(*ops));
f2f23566	213
48e23311 VD	214	ops->get_regs_len = dsa_master_get_regs_len;
48e23311 VD	215	ops->get_regs = dsa_master_get_regs;
f2f23566 VD	216	ops->get_sset_count = dsa_master_get_sset_count;
	217	ops->get_ethtool_stats = dsa_master_get_ethtool_stats;
	218	ops->get_strings = dsa_master_get_strings;
cf963573	219	ops->get_ethtool_phy_stats = dsa_master_get_ethtool_phy_stats;
f2f23566 VD	220
	221	dev->ethtool_ops = ops;
	222
	223	return 0;
	224	}
	225
17a22fcf	226	static void dsa_master_ethtool_teardown(struct net_device *dev)
f2f23566	227	{
2f657a60	228	struct dsa_port *cpu_dp = dev->dsa_ptr;
f2f23566	229
7ec764ee VD	230	dev->ethtool_ops = cpu_dp->orig_ethtool_ops;
7ec764ee VD	231	cpu_dp->orig_ethtool_ops = NULL;
f2f23566	232	}
17a22fcf	233
da7b9e9b FF	234	static int dsa_master_ndo_setup(struct net_device *dev)
	235	{
	236	struct dsa_port *cpu_dp = dev->dsa_ptr;
	237	struct dsa_switch *ds = cpu_dp->ds;
	238	struct net_device_ops *ops;
	239
	240	if (dev->netdev_ops->ndo_get_phys_port_name)
	241	return 0;
	242
	243	ops = devm_kzalloc(ds->dev, sizeof(*ops), GFP_KERNEL);
	244	if (!ops)
	245	return -ENOMEM;
	246
	247	cpu_dp->orig_ndo_ops = dev->netdev_ops;
	248	if (cpu_dp->orig_ndo_ops)
	249	memcpy(ops, cpu_dp->orig_ndo_ops, sizeof(*ops));
	250
	251	ops->ndo_get_phys_port_name = dsa_master_get_phys_port_name;
	252
	253	dev->netdev_ops = ops;
	254
	255	return 0;
	256	}
	257
	258	static void dsa_master_ndo_teardown(struct net_device *dev)
	259	{
	260	struct dsa_port *cpu_dp = dev->dsa_ptr;
	261
	262	dev->netdev_ops = cpu_dp->orig_ndo_ops;
	263	cpu_dp->orig_ndo_ops = NULL;
	264	}
	265
a3d7e01d FF	266	static ssize_t tagging_show(struct device d, struct device_attribute attr,
	267	char *buf)
	268	{
	269	struct net_device *dev = to_net_dev(d);
	270	struct dsa_port *cpu_dp = dev->dsa_ptr;
	271
	272	return sprintf(buf, "%s\n",
	273	dsa_tag_protocol_to_str(cpu_dp->tag_ops));
	274	}
	275	static DEVICE_ATTR_RO(tagging);
	276
	277	static struct attribute *dsa_slave_attrs[] = {
	278	&dev_attr_tagging.attr,
	279	NULL
	280	};
	281
	282	static const struct attribute_group dsa_group = {
	283	.name = "dsa",
	284	.attrs = dsa_slave_attrs,
	285	};
	286
a60956ed	287	static void dsa_master_set_mtu(struct net_device dev, struct dsa_port cpu_dp)
dc0fe7d4 AL	288	{
	289	unsigned int mtu = ETH_DATA_LEN + cpu_dp->tag_ops->overhead;
	290	int err;
	291
	292	rtnl_lock();
	293	if (mtu <= dev->max_mtu) {
	294	err = dev_set_mtu(dev, mtu);
	295	if (err)
	296	netdev_dbg(dev, "Unable to set MTU to include for DSA overheads\n");
	297	}
	298	rtnl_unlock();
	299	}
	300
91ba4795 AL	301	static void dsa_master_reset_mtu(struct net_device *dev)
	302	{
	303	int err;
	304
	305	rtnl_lock();
	306	err = dev_set_mtu(dev, ETH_DATA_LEN);
	307	if (err)
	308	netdev_dbg(dev,
	309	"Unable to reset MTU to exclude DSA overheads\n");
	310	rtnl_unlock();
	311	}
	312
17a22fcf VD	313	int dsa_master_setup(struct net_device dev, struct dsa_port cpu_dp)
17a22fcf VD	314	{
a3d7e01d FF	315	int ret;
a3d7e01d FF	316
dc0fe7d4 AL	317	dsa_master_set_mtu(dev, cpu_dp);
dc0fe7d4 AL	318
17a22fcf VD	319	/* If we use a tagging format that doesn't have an ethertype
	320	* field, make sure that all packets from this point on get
	321	* sent to the tag format's receive function.
	322	*/
	323	wmb();
	324
	325	dev->dsa_ptr = cpu_dp;
a3d7e01d FF	326	ret = dsa_master_ethtool_setup(dev);
	327	if (ret)
	328	return ret;
	329
da7b9e9b FF	330	ret = dsa_master_ndo_setup(dev);
	331	if (ret)
	332	goto out_err_ethtool_teardown;
	333
a3d7e01d FF	334	ret = sysfs_create_group(&dev->dev.kobj, &dsa_group);
a3d7e01d FF	335	if (ret)
da7b9e9b FF	336	goto out_err_ndo_teardown;
	337
	338	return ret;
a3d7e01d	339
da7b9e9b FF	340	out_err_ndo_teardown:
	341	dsa_master_ndo_teardown(dev);
	342	out_err_ethtool_teardown:
	343	dsa_master_ethtool_teardown(dev);
a3d7e01d	344	return ret;
17a22fcf VD	345	}
	346
	347	void dsa_master_teardown(struct net_device *dev)
	348	{
a3d7e01d	349	sysfs_remove_group(&dev->dev.kobj, &dsa_group);
da7b9e9b	350	dsa_master_ndo_teardown(dev);
17a22fcf	351	dsa_master_ethtool_teardown(dev);
91ba4795	352	dsa_master_reset_mtu(dev);
17a22fcf VD	353
	354	dev->dsa_ptr = NULL;
	355
	356	/* If we used a tagging format that doesn't have an ethertype
	357	* field, make sure that all packets from this point get sent
	358	* without the tag and go through the regular receive path.
	359	*/
	360	wmb();
	361	}