Merge the //depot/user/yar/vlan branch into CVS. It contains some collective

work by yar, thompsa and myself. The checksum offloading part also involves
work done by Mihail Balikov.

The most important changes:

o   Instead of global linked list of all vlan softc use a per-trunk
  hash. The size of hash is dynamically adjusted, depending on
  number of entries. This changes struct ifnet, replacing counter
  of vlans with a pointer to trunk structure. This change is an
  improvement for setups with big number of VLANs, several interfaces
  and several CPUs. It is a small regression for a setup with a single
  VLAN interface.
    An alternative to dynamic hash is a per-trunk static array with
  4096 entries, which is a compile time option - VLAN_ARRAY. In my
  experiments the array is not an improvement, probably because such
  a big trunk structure doesn't fit into CPU cache.
o   Introduce an UMA zone for VLAN tags. Since drivers depend on it,
  the zone is declared in kern_mbuf.c, not in optional vlan(4) driver.
  This change is a big improvement for any setup utilizing vlan(4).
o   Use rwlock(9) instead of mutex(9) for locking. We are the first
  ones to do this! :)
o   Some drivers can do hardware VLAN tagging + hardware checksum
  offloading. Add an infrastructure for this. Whenever vlan(4) is
  attached to a parent or parent configuration is changed, the flags
  on vlan(4) interface are updated.

In collaboration with:	yar, thompsa
In collaboration with:	Mihail Balikov <mihail.balikov interbgc.com>

1 files changed, 5 insertions, 0 deletions

diff --git a/sys/sys/mbuf.h b/sys/sys/mbuf.h
index 81c44a6..d762a29 100644
--- a/sys/sys/mbuf.h
+++ b/sys/sys/mbuf.h
@@ -337,6 +337,7 @@ extern uma_zone_t	zone_jumbo4;
 extern uma_zone_t	zone_jumbo9;
 extern uma_zone_t	zone_jumbo16;
 extern uma_zone_t	zone_ext_refcnt;
+extern uma_zone_t	zone_mtag_vlan;
 
 static __inline struct mbuf	*m_get(int how, short type);
 static __inline struct mbuf	*m_gethdr(int how, short type);
@@ -760,6 +761,10 @@ struct	mbuf	*m_uiotombuf(struct uio *, int, int, int);
 #define	PACKET_TAG_IPOPTIONS			27 /* Saved IP options */
 #define	PACKET_TAG_CARP                         28 /* CARP info */
 
+/* Specific cookies and tags. */
+#define	MTAG_VLAN				1035328035
+#define	MTAG_VLAN_TAG				0 /* tag of VLAN interface */
+
 /* Packet tag routines. */
 struct	m_tag	*m_tag_alloc(u_int32_t, int, int, int);
 void		 m_tag_delete(struct mbuf *, struct m_tag *);