From f5184d267c1aedb9b7a8cc44e08ff6b8d382c3b5 Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Mon, 12 May 2008 20:48:31 -0700 Subject: net: Allow netdevices to specify needed head/tailroom This patch adds needed_headroom/needed_tailroom members to struct net_device and updates many places that allocate sbks to use them. Not all of them can be converted though, and I'm sure I missed some (I mostly grepped for LL_RESERVED_SPACE) Signed-off-by: Johannes Berg Signed-off-by: David S. Miller --- include/linux/netdevice.h | 16 ++++++++++++++-- 1 file changed, 14 insertions(+), 2 deletions(-) (limited to 'include/linux') diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index a3fb57fde62..b11e6e19e96 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -246,11 +246,16 @@ struct hh_cache * * We could use other alignment values, but we must maintain the * relationship HH alignment <= LL alignment. + * + * LL_ALLOCATED_SPACE also takes into account the tailroom the device + * may need. */ #define LL_RESERVED_SPACE(dev) \ - (((dev)->hard_header_len&~(HH_DATA_MOD - 1)) + HH_DATA_MOD) + ((((dev)->hard_header_len+(dev)->needed_headroom)&~(HH_DATA_MOD - 1)) + HH_DATA_MOD) #define LL_RESERVED_SPACE_EXTRA(dev,extra) \ - ((((dev)->hard_header_len+extra)&~(HH_DATA_MOD - 1)) + HH_DATA_MOD) + ((((dev)->hard_header_len+(dev)->needed_headroom+(extra))&~(HH_DATA_MOD - 1)) + HH_DATA_MOD) +#define LL_ALLOCATED_SPACE(dev) \ + ((((dev)->hard_header_len+(dev)->needed_headroom+(dev)->needed_tailroom)&~(HH_DATA_MOD - 1)) + HH_DATA_MOD) struct header_ops { int (*create) (struct sk_buff *skb, struct net_device *dev, @@ -569,6 +574,13 @@ struct net_device unsigned short type; /* interface hardware type */ unsigned short hard_header_len; /* hardware hdr length */ + /* extra head- and tailroom the hardware may need, but not in all cases + * can this be guaranteed, especially tailroom. Some cases also use + * LL_MAX_HEADER instead to allocate the skb. + */ + unsigned short needed_headroom; + unsigned short needed_tailroom; + struct net_device *master; /* Pointer to master device of a group, * which this device is member of. */ -- cgit v1.2.3