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brintos / linux-shallow public Read only

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1.. SPDX-License-Identifier: GPL-2.02 3==============================================4Netdev private dataroom for 6lowpan interfaces5==============================================6 7All 6lowpan able net devices, means all interfaces with ARPHRD_6LOWPAN,8must have "struct lowpan_priv" placed at beginning of netdev_priv.9 10The priv_size of each interface should be calculate by::11 12 dev->priv_size = LOWPAN_PRIV_SIZE(LL_6LOWPAN_PRIV_DATA);13 14Where LL_PRIV_6LOWPAN_DATA is sizeof linklayer 6lowpan private data struct.15To access the LL_PRIV_6LOWPAN_DATA structure you can cast::16 17 lowpan_priv(dev)-priv;18 19to your LL_6LOWPAN_PRIV_DATA structure.20 21Before registering the lowpan netdev interface you must run::22 23 lowpan_netdev_setup(dev, LOWPAN_LLTYPE_FOOBAR);24 25wheres LOWPAN_LLTYPE_FOOBAR is a define for your 6LoWPAN linklayer type of26enum lowpan_lltypes.27 28Example to evaluate the private usually you can do::29 30 static inline struct lowpan_priv_foobar *31 lowpan_foobar_priv(struct net_device *dev)32 {33	return (struct lowpan_priv_foobar *)lowpan_priv(dev)->priv;34 }35 36 switch (dev->type) {37 case ARPHRD_6LOWPAN:38	lowpan_priv = lowpan_priv(dev);39	/* do great stuff which is ARPHRD_6LOWPAN related */40	switch (lowpan_priv->lltype) {41	case LOWPAN_LLTYPE_FOOBAR:42		/* do 802.15.4 6LoWPAN handling here */43		lowpan_foobar_priv(dev)->bar = foo;44		break;45	...46	}47	break;48 ...49 }50 51In case of generic 6lowpan branch ("net/6lowpan") you can remove the check52on ARPHRD_6LOWPAN, because you can be sure that these function are called53by ARPHRD_6LOWPAN interfaces.54