Commit 65ac6a5f authored by Jesse Gross's avatar Jesse Gross Committed by David S. Miller
Browse files

vlan: Avoid hash table lookup to find group. 



A struct net_device always maps to zero or one vlan groups and we
always know the device when we are looking up a group.  We currently
do a hash table lookup on the device to find the group but it is
much simpler to just store a pointer.

Signed-off-by: default avatarJesse Gross <jesse@nicira.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 7b9c6090

include/linux/if_vlan.h

+19 −0
Original line number Diff line number Diff line
@@ -16,6 +16,7 @@ 
#ifdef __KERNEL__

#include <linux/netdevice.h>

#include <linux/etherdevice.h>

#include <linux/rtnetlink.h>



#define VLAN_HLEN	4		/* The additional bytes (on top of the Ethernet header)

					 * that VLAN requires.
@@ -114,6 +115,18 @@ static inline void vlan_group_set_device(struct vlan_group *vg, 
#define vlan_tx_tag_get(__skb)		((__skb)->vlan_tci & ~VLAN_TAG_PRESENT)



#if defined(CONFIG_VLAN_8021Q) || defined(CONFIG_VLAN_8021Q_MODULE)

/* Must be invoked with rcu_read_lock or with RTNL. */

static inline struct net_device *vlan_find_dev(struct net_device *real_dev,

					       u16 vlan_id)

{

	struct vlan_group *grp = rcu_dereference_rtnl(real_dev->vlgrp);



	if (grp)

		return vlan_group_get_device(grp, vlan_id);



	return NULL;

}



extern struct net_device *vlan_dev_real_dev(const struct net_device *dev);

extern u16 vlan_dev_vlan_id(const struct net_device *dev);
@@ -128,6 +141,12 @@ vlan_gro_frags(struct napi_struct *napi, struct vlan_group *grp, 
	       unsigned int vlan_tci);



#else

static inline struct net_device *vlan_find_dev(struct net_device *real_dev,

					       u16 vlan_id)

{

	return NULL;

}



static inline struct net_device *vlan_dev_real_dev(const struct net_device *dev)

{

	BUG();

include/linux/netdevice.h

+4 −1
Original line number Diff line number Diff line
@@ -943,6 +943,9 @@ struct net_device { 


	/* Protocol specific pointers */



#if defined(CONFIG_VLAN_8021Q) || defined(CONFIG_VLAN_8021Q_MODULE)

	struct vlan_group	*vlgrp;		/* VLAN group */

#endif

#ifdef CONFIG_NET_DSA

	void			*dsa_ptr;	/* dsa specific data */

#endif

net/8021q/vlan.c

+10 −54
Original line number Diff line number Diff line
@@ -44,9 +44,6 @@ 


int vlan_net_id __read_mostly;



/* Our listing of VLAN group(s) */

static struct hlist_head vlan_group_hash[VLAN_GRP_HASH_SIZE];



const char vlan_fullname[] = "802.1Q VLAN Support";

const char vlan_version[] = DRV_VERSION;

static const char vlan_copyright[] = "Ben Greear <greearb@candelatech.com>";
@@ -59,40 +56,6 @@ static struct packet_type vlan_packet_type __read_mostly = { 


/* End of global variables definitions. */



static inline unsigned int vlan_grp_hashfn(unsigned int idx)

{

	return ((idx >> VLAN_GRP_HASH_SHIFT) ^ idx) & VLAN_GRP_HASH_MASK;

}



/* Must be invoked with RCU read lock (no preempt) */

static struct vlan_group *__vlan_find_group(struct net_device *real_dev)

{

	struct vlan_group *grp;

	struct hlist_node *n;

	int hash = vlan_grp_hashfn(real_dev->ifindex);



	hlist_for_each_entry_rcu(grp, n, &vlan_group_hash[hash], hlist) {

		if (grp->real_dev == real_dev)

			return grp;

	}



	return NULL;

}



/*  Find the protocol handler.  Assumes VID < VLAN_VID_MASK.

 *

 * Must be invoked with RCU read lock (no preempt)

 */

struct net_device *__find_vlan_dev(struct net_device *real_dev, u16 vlan_id)

{

	struct vlan_group *grp = __vlan_find_group(real_dev);



	if (grp)

		return vlan_group_get_device(grp, vlan_id);



	return NULL;

}



static void vlan_group_free(struct vlan_group *grp)

{

	int i;
@@ -111,8 +74,6 @@ static struct vlan_group *vlan_group_alloc(struct net_device *real_dev) 
		return NULL;



	grp->real_dev = real_dev;

	hlist_add_head_rcu(&grp->hlist,

			&vlan_group_hash[vlan_grp_hashfn(real_dev->ifindex)]);

	return grp;

}
@@ -151,7 +112,7 @@ void unregister_vlan_dev(struct net_device *dev, struct list_head *head) 


	ASSERT_RTNL();



	grp = __vlan_find_group(real_dev);

	grp = real_dev->vlgrp;

	BUG_ON(!grp);



	/* Take it out of our own structures, but be sure to interlock with
@@ -173,11 +134,10 @@ void unregister_vlan_dev(struct net_device *dev, struct list_head *head) 
	if (grp->nr_vlans == 0) {

		vlan_gvrp_uninit_applicant(real_dev);



		rcu_assign_pointer(real_dev->vlgrp, NULL);

		if (real_dev->features & NETIF_F_HW_VLAN_RX)

			ops->ndo_vlan_rx_register(real_dev, NULL);



		hlist_del_rcu(&grp->hlist);



		/* Free the group, after all cpu's are done. */

		call_rcu(&grp->rcu, vlan_rcu_free);

	}
@@ -207,7 +167,7 @@ int vlan_check_real_dev(struct net_device *real_dev, u16 vlan_id) 
		return -EOPNOTSUPP;

	}



	if (__find_vlan_dev(real_dev, vlan_id) != NULL)

	if (vlan_find_dev(real_dev, vlan_id) != NULL)

		return -EEXIST;



	return 0;
@@ -222,7 +182,7 @@ int register_vlan_dev(struct net_device *dev) 
	struct vlan_group *grp, *ngrp = NULL;

	int err;



	grp = __vlan_find_group(real_dev);

	grp = real_dev->vlgrp;

	if (!grp) {

		ngrp = grp = vlan_group_alloc(real_dev);

		if (!grp)
@@ -252,8 +212,11 @@ int register_vlan_dev(struct net_device *dev) 
	vlan_group_set_device(grp, vlan_id, dev);

	grp->nr_vlans++;



	if (ngrp && real_dev->features & NETIF_F_HW_VLAN_RX)

	if (ngrp) {

		if (real_dev->features & NETIF_F_HW_VLAN_RX)

			ops->ndo_vlan_rx_register(real_dev, ngrp);

		rcu_assign_pointer(real_dev->vlgrp, ngrp);

	}

	if (real_dev->features & NETIF_F_HW_VLAN_FILTER)

		ops->ndo_vlan_rx_add_vid(real_dev, vlan_id);
@@ -264,7 +227,6 @@ out_uninit_applicant: 
		vlan_gvrp_uninit_applicant(real_dev);

out_free_group:

	if (ngrp) {

		hlist_del_rcu(&ngrp->hlist);

		/* Free the group, after all cpu's are done. */

		call_rcu(&ngrp->rcu, vlan_rcu_free);

	}
@@ -428,7 +390,7 @@ static int vlan_device_event(struct notifier_block *unused, unsigned long event, 
		dev->netdev_ops->ndo_vlan_rx_add_vid(dev, 0);

	}



	grp = __vlan_find_group(dev);

	grp = dev->vlgrp;

	if (!grp)

		goto out;
@@ -746,8 +708,6 @@ err0: 


static void __exit vlan_cleanup_module(void)

{

	unsigned int i;



	vlan_ioctl_set(NULL);

	vlan_netlink_fini();
@@ -755,10 +715,6 @@ static void __exit vlan_cleanup_module(void) 


	dev_remove_pack(&vlan_packet_type);



	/* This table must be empty if there are no module references left. */

	for (i = 0; i < VLAN_GRP_HASH_SIZE; i++)

		BUG_ON(!hlist_empty(&vlan_group_hash[i]));



	unregister_pernet_subsys(&vlan_net_ops);

	rcu_barrier(); /* Wait for completion of call_rcu()'s */

net/8021q/vlan.h

+0 −17
Original line number Diff line number Diff line
@@ -72,23 +72,6 @@ static inline struct vlan_dev_info *vlan_dev_info(const struct net_device *dev) 
	return netdev_priv(dev);

}



#define VLAN_GRP_HASH_SHIFT	5

#define VLAN_GRP_HASH_SIZE	(1 << VLAN_GRP_HASH_SHIFT)

#define VLAN_GRP_HASH_MASK	(VLAN_GRP_HASH_SIZE - 1)



/*  Find a VLAN device by the MAC address of its Ethernet device, and

 *  it's VLAN ID.  The default configuration is to have VLAN's scope

 *  to be box-wide, so the MAC will be ignored.  The mac will only be

 *  looked at if we are configured to have a separate set of VLANs per

 *  each MAC addressable interface.  Note that this latter option does

 *  NOT follow the spec for VLANs, but may be useful for doing very

 *  large quantities of VLAN MUX/DEMUX onto FrameRelay or ATM PVCs.

 *

 *  Must be invoked with rcu_read_lock (ie preempt disabled)

 *  or with RTNL.

 */

struct net_device *__find_vlan_dev(struct net_device *real_dev, u16 vlan_id);



/* found in vlan_dev.c */

int vlan_skb_recv(struct sk_buff *skb, struct net_device *dev,

		  struct packet_type *ptype, struct net_device *orig_dev);

net/8021q/vlan_dev.c

+1 −1
Original line number Diff line number Diff line
@@ -158,7 +158,7 @@ int vlan_skb_recv(struct sk_buff *skb, struct net_device *dev, 
	vlan_id = vlan_tci & VLAN_VID_MASK;



	rcu_read_lock();

	vlan_dev = __find_vlan_dev(dev, vlan_id);

	vlan_dev = vlan_find_dev(dev, vlan_id);



	/* If the VLAN device is defined, we use it.

	 * If not, and the VID is 0, it is a 802.1p packet (not

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