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Date: Thu, 17 Dec 2015 13:45:08 +0530
From: Hariprasad Shenai <hariprasad@...lsio.com>
To: netdev@...r.kernel.org
Cc: davem@...emloft.net, leedom@...lsio.com, nirranjan@...lsio.com,
Hariprasad Shenai <hariprasad@...lsio.com>
Subject: [PATCHv2 net-next 2/4] cxgb4: Add API to alloc l2t entry; also update existing ones
Based on original work by Kumar Sanghvi <kumaras@...lsio.com>
Signed-off-by: Hariprasad Shenai <hariprasad@...lsio.com>
---
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);
--
2.3.4
--
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