From f7502659cec8f2165805e967e113c0894b931181 Mon Sep 17 00:00:00 2001 From: Hariprasad Shenai Date: Thu, 17 Dec 2015 13:45:08 +0530 Subject: [PATCH] cxgb4: Add API to alloc l2t entry; also update existing ones Based on original work by Kumar Sanghvi Signed-off-by: Hariprasad Shenai Signed-off-by: David S. Miller --- drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c | 10 +- drivers/net/ethernet/chelsio/cxgb4/l2t.c | 125 +++++++++++++++++++++--- drivers/net/ethernet/chelsio/cxgb4/l2t.h | 7 +- 3 files changed, 117 insertions(+), 25 deletions(-) diff --git a/drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c b/drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c index edd706e..8490c84 100644 --- a/drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c +++ b/drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c @@ -1181,16 +1181,10 @@ static int set_filter_wr(struct adapter *adapter, int fidx) */ if (f->fs.newdmac || f->fs.newvlan) { /* allocate L2T entry for new filter */ - f->l2t = t4_l2t_alloc_switching(adapter->l2t); + f->l2t = t4_l2t_alloc_switching(adapter, f->fs.vlan, + f->fs.eport, f->fs.dmac); if (f->l2t == NULL) { kfree_skb(skb); - return -EAGAIN; - } - if (t4_l2t_set_switching(adapter, f->l2t, f->fs.vlan, - f->fs.eport, f->fs.dmac)) { - cxgb4_l2t_release(f->l2t); - f->l2t = NULL; - kfree_skb(skb); return -ENOMEM; } } diff --git a/drivers/net/ethernet/chelsio/cxgb4/l2t.c b/drivers/net/ethernet/chelsio/cxgb4/l2t.c index 7234b82..d1b3b3a 100644 --- a/drivers/net/ethernet/chelsio/cxgb4/l2t.c +++ b/drivers/net/ethernet/chelsio/cxgb4/l2t.c @@ -305,9 +305,82 @@ found: return e; } -/* - * Called when an L2T entry has no more users. +static struct l2t_entry *find_or_alloc_l2e(struct l2t_data *d, u16 vlan, + u8 port, u8 *dmac) +{ + struct l2t_entry *end, *e, **p; + struct l2t_entry *first_free = NULL; + + for (e = &d->l2tab[0], end = &d->l2tab[d->l2t_size]; e != end; ++e) { + if (atomic_read(&e->refcnt) == 0) { + if (!first_free) + first_free = e; + } else { + if (e->state == L2T_STATE_SWITCHING) { + if (ether_addr_equal(e->dmac, dmac) && + (e->vlan == vlan) && (e->lport == port)) + goto exists; + } + } + } + + if (first_free) { + e = first_free; + goto found; + } + + return NULL; + +found: + /* The entry we found may be an inactive entry that is + * presently in the hash table. We need to remove it. + */ + if (e->state < L2T_STATE_SWITCHING) + for (p = &d->l2tab[e->hash].first; *p; p = &(*p)->next) + if (*p == e) { + *p = e->next; + e->next = NULL; + break; + } + e->state = L2T_STATE_UNUSED; + +exists: + return e; +} + +/* Called when an L2T entry has no more users. The entry is left in the hash + * table since it is likely to be reused but we also bump nfree to indicate + * that the entry can be reallocated for a different neighbor. We also drop + * the existing neighbor reference in case the neighbor is going away and is + * waiting on our reference. + * + * Because entries can be reallocated to other neighbors once their ref count + * drops to 0 we need to take the entry's lock to avoid races with a new + * incarnation. */ +static void _t4_l2e_free(struct l2t_entry *e) +{ + struct l2t_data *d; + + if (atomic_read(&e->refcnt) == 0) { /* hasn't been recycled */ + if (e->neigh) { + neigh_release(e->neigh); + e->neigh = NULL; + } + while (e->arpq_head) { + struct sk_buff *skb = e->arpq_head; + + e->arpq_head = skb->next; + kfree_skb(skb); + } + e->arpq_tail = NULL; + } + + d = container_of(e, struct l2t_data, l2tab[e->idx]); + atomic_inc(&d->nfree); +} + +/* Locked version of _t4_l2e_free */ static void t4_l2e_free(struct l2t_entry *e) { struct l2t_data *d; @@ -529,33 +602,57 @@ void t4_l2t_update(struct adapter *adap, struct neighbour *neigh) * explicitly freed and while busy they are not on any hash chain, so normal * address resolution updates do not see them. */ -struct l2t_entry *t4_l2t_alloc_switching(struct l2t_data *d) +struct l2t_entry *t4_l2t_alloc_switching(struct adapter *adap, u16 vlan, + u8 port, u8 *eth_addr) { + struct l2t_data *d = adap->l2t; struct l2t_entry *e; + int ret; write_lock_bh(&d->lock); - e = alloc_l2e(d); + e = find_or_alloc_l2e(d, vlan, port, eth_addr); if (e) { spin_lock(&e->lock); /* avoid race with t4_l2t_free */ - e->state = L2T_STATE_SWITCHING; - atomic_set(&e->refcnt, 1); + if (!atomic_read(&e->refcnt)) { + e->state = L2T_STATE_SWITCHING; + e->vlan = vlan; + e->lport = port; + ether_addr_copy(e->dmac, eth_addr); + atomic_set(&e->refcnt, 1); + ret = write_l2e(adap, e, 0); + if (ret < 0) { + _t4_l2e_free(e); + spin_unlock(&e->lock); + write_unlock_bh(&d->lock); + return NULL; + } + } else { + atomic_inc(&e->refcnt); + } + spin_unlock(&e->lock); } write_unlock_bh(&d->lock); return e; } -/* Sets/updates the contents of a switching L2T entry that has been allocated - * with an earlier call to @t4_l2t_alloc_switching. +/** + * @dev: net_device pointer + * @vlan: VLAN Id + * @port: Associated port + * @dmac: Destination MAC address to add to L2T + * Returns pointer to the allocated l2t entry + * + * Allocates an L2T entry for use by switching rule of a filter */ -int t4_l2t_set_switching(struct adapter *adap, struct l2t_entry *e, u16 vlan, - u8 port, u8 *eth_addr) +struct l2t_entry *cxgb4_l2t_alloc_switching(struct net_device *dev, u16 vlan, + u8 port, u8 *dmac) { - e->vlan = vlan; - e->lport = port; - memcpy(e->dmac, eth_addr, ETH_ALEN); - return write_l2e(adap, e, 0); + struct adapter *adap = netdev2adap(dev); + + return t4_l2t_alloc_switching(adap, vlan, port, dmac); } +EXPORT_SYMBOL(cxgb4_l2t_alloc_switching); struct l2t_data *t4_init_l2t(unsigned int l2t_start, unsigned int l2t_end) { diff --git a/drivers/net/ethernet/chelsio/cxgb4/l2t.h b/drivers/net/ethernet/chelsio/cxgb4/l2t.h index b38dc52..17803a8 100644 --- a/drivers/net/ethernet/chelsio/cxgb4/l2t.h +++ b/drivers/net/ethernet/chelsio/cxgb4/l2t.h @@ -114,10 +114,11 @@ struct l2t_entry *cxgb4_l2t_get(struct l2t_data *d, struct neighbour *neigh, unsigned int priority); u64 cxgb4_select_ntuple(struct net_device *dev, const struct l2t_entry *l2t); +struct l2t_entry *cxgb4_l2t_alloc_switching(struct net_device *dev, u16 vlan, + u8 port, u8 *dmac); void t4_l2t_update(struct adapter *adap, struct neighbour *neigh); -struct l2t_entry *t4_l2t_alloc_switching(struct l2t_data *d); -int t4_l2t_set_switching(struct adapter *adap, struct l2t_entry *e, u16 vlan, - u8 port, u8 *eth_addr); +struct l2t_entry *t4_l2t_alloc_switching(struct adapter *adap, u16 vlan, + u8 port, u8 *dmac); struct l2t_data *t4_init_l2t(unsigned int l2t_start, unsigned int l2t_end); void do_l2t_write_rpl(struct adapter *p, const struct cpl_l2t_write_rpl *rpl); -- 2.7.4