Re: [RFCv2 bluetooth-next 2/2] 6lowpan: add generic 6lowpan netdev private data

[Stefan Schmidt <stefan@osg.samsung.com>]

Hello.

On 31/07/15 14:38, Alexander Aring wrote:
> This patch introduced the 6lowpan netdev private data struct. We name it
> lowpan_priv and it's placed at the beginning of netdev private data. All
> lowpan interfaces should allocate this room at first of netdev private
> data. 6LoWPAN LL private data can be allocate by additional netdev private
> data, e.g. dev->priv_size should be "sizeof(struct lowpan_priv) +
> sizeof(LL_LOWPAN_PRIVATE_DATA)".
>
> Signed-off-by: Alexander Aring<alex.aring@gmail.com>
> ---
>   include/net/6lowpan.h              | 18 ++++++++++++++++++
>   net/bluetooth/6lowpan.c            |  7 +++++--
>   net/ieee802154/6lowpan/6lowpan_i.h |  3 ++-
>   net/ieee802154/6lowpan/core.c      |  5 ++++-
>   4 files changed, 29 insertions(+), 4 deletions(-)
>
> diff --git a/include/net/6lowpan.h b/include/net/6lowpan.h
> index dc03d77..a955be2 100644
> --- a/include/net/6lowpan.h
> +++ b/include/net/6lowpan.h
> @@ -197,6 +197,24 @@
>   #define LOWPAN_NHC_UDP_CS_P_11	0xF3 /* source & dest = 0xF0B + 4bit inline */
>   #define LOWPAN_NHC_UDP_CS_C	0x04 /* checksum elided */
>   
> +enum lowpan_ll_types {
> +	LOWPAN_LL_TYPE_BTLE,
> +	LOWPAN_LL_TYPE_IEEE802154,
> +};
> +
> +struct lowpan_priv {
> +	enum lowpan_ll_types ll_type;
> +
> +	/* must be last */
> +	u8 priv[0] __aligned(sizeof(void *));
> +};
> +
> +static inline
> +struct lowpan_priv *lowpan_priv(const struct net_device *dev)
> +{
> +	return netdev_priv(dev);
> +}
> +
>   #ifdef DEBUG
>   /* print data in line */
>   static inline void raw_dump_inline(const char *caller, char *msg,
> diff --git a/net/bluetooth/6lowpan.c b/net/bluetooth/6lowpan.c
> index 24ed5b0..eb61121 100644
> --- a/net/bluetooth/6lowpan.c
> +++ b/net/bluetooth/6lowpan.c
> @@ -85,7 +85,7 @@ struct lowpan_dev {
>   
>   static inline struct lowpan_dev *lowpan_dev(const struct net_device *netdev)
>   {
> -	return netdev_priv(netdev);
> +	return (struct lowpan_dev *)lowpan_priv(netdev)->priv;
>   }
>   
>   static inline void peer_add(struct lowpan_dev *dev, struct lowpan_peer *peer)
> @@ -848,7 +848,8 @@ static int setup_netdev(struct l2cap_chan *chan, struct lowpan_dev **dev)
>   	struct net_device *netdev;
>   	int err = 0;
>   
> -	netdev = alloc_netdev(sizeof(struct lowpan_dev), IFACE_NAME_TEMPLATE,
> +	netdev = alloc_netdev(sizeof(struct lowpan_priv) +
> +			      sizeof(struct lowpan_dev), IFACE_NAME_TEMPLATE,
>   			      NET_NAME_UNKNOWN, netdev_setup);
>   	if (!netdev)
>   		return -ENOMEM;
> @@ -869,6 +870,8 @@ static int setup_netdev(struct l2cap_chan *chan, struct lowpan_dev **dev)
>   	list_add_rcu(&(*dev)->list, &bt_6lowpan_devices);
>   	spin_unlock(&devices_lock);
>   
> +	lowpan_priv(netdev)->ll_type = LOWPAN_LL_TYPE_BTLE;
> +
>   	err = register_netdev(netdev);
>   	if (err < 0) {
>   		BT_INFO("register_netdev failed %d", err);
> diff --git a/net/ieee802154/6lowpan/6lowpan_i.h b/net/ieee802154/6lowpan/6lowpan_i.h
> index e50f69d..0dd4e46 100644
> --- a/net/ieee802154/6lowpan/6lowpan_i.h
> +++ b/net/ieee802154/6lowpan/6lowpan_i.h
> @@ -5,6 +5,7 @@
>   
>   #include <net/ieee802154_netdev.h>
>   #include <net/inet_frag.h>
> +#include <net/6lowpan.h>
>   
>   struct lowpan_create_arg {
>   	u16 tag;
> @@ -52,7 +53,7 @@ struct lowpan_dev_info {
>   static inline struct
>   lowpan_dev_info *lowpan_dev_info(const struct net_device *dev)
>   {
> -	return netdev_priv(dev);
> +	return (struct lowpan_dev_info *)lowpan_priv(dev)->priv;
>   }
>   
>   extern struct list_head lowpan_devices;
> diff --git a/net/ieee802154/6lowpan/core.c b/net/ieee802154/6lowpan/core.c
> index f20a387..ede602c 100644
> --- a/net/ieee802154/6lowpan/core.c
> +++ b/net/ieee802154/6lowpan/core.c
> @@ -153,6 +153,8 @@ static int lowpan_newlink(struct net *src_net, struct net_device *dev,
>   	list_add_tail(&entry->list, &lowpan_devices);
>   	mutex_unlock(&lowpan_dev_info(dev)->dev_list_mtx);
>   
> +	lowpan_priv(dev)->ll_type = LOWPAN_LL_TYPE_IEEE802154;
> +
>   	ret = register_netdevice(dev);
>   	if (ret >= 0) {
>   		if (!lowpan_open_count)
> @@ -193,7 +195,8 @@ static void lowpan_dellink(struct net_device *dev, struct list_head *head)
>   
>   static struct rtnl_link_ops lowpan_link_ops __read_mostly = {
>   	.kind		= "lowpan",
> -	.priv_size	= sizeof(struct lowpan_dev_info),
> +	.priv_size	= sizeof(struct lowpan_priv) +
> +			  sizeof(struct lowpan_dev_info),
>   	.setup		= lowpan_setup,
>   	.newlink	= lowpan_newlink,
>   	.dellink	= lowpan_dellink,

Reviewed-by: Stefan Schmidt <stefan@osg.samsung.com>

regards
Stefan Schmidt