1 files changed, 624 insertions, 0 deletions

diff --git a/drivers/net/cxgb4/l2t.c b/drivers/net/cxgb4/l2t.c
new file mode 100644
index 000000000000..9f96724a133a
--- /dev/null
+++ b/drivers/net/cxgb4/l2t.c
@@ -0,0 +1,624 @@
+/*
+ * This file is part of the Chelsio T4 Ethernet driver for Linux.
+ *
+ * Copyright (c) 2003-2010 Chelsio Communications, Inc. All rights reserved.
+ *
+ * This software is available to you under a choice of one of two
+ * licenses.  You may choose to be licensed under the terms of the GNU
+ * General Public License (GPL) Version 2, available from the file
+ * COPYING in the main directory of this source tree, or the
+ * OpenIB.org BSD license below:
+ *
+ *     Redistribution and use in source and binary forms, with or
+ *     without modification, are permitted provided that the following
+ *     conditions are met:
+ *
+ *      - Redistributions of source code must retain the above
+ *        copyright notice, this list of conditions and the following
+ *        disclaimer.
+ *
+ *      - Redistributions in binary form must reproduce the above
+ *        copyright notice, this list of conditions and the following
+ *        disclaimer in the documentation and/or other materials
+ *        provided with the distribution.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#include <linux/skbuff.h>
+#include <linux/netdevice.h>
+#include <linux/if.h>
+#include <linux/if_vlan.h>
+#include <linux/jhash.h>
+#include <net/neighbour.h>
+#include "cxgb4.h"
+#include "l2t.h"
+#include "t4_msg.h"
+#include "t4fw_api.h"
+
+#define VLAN_NONE 0xfff
+
+/* identifies sync vs async L2T_WRITE_REQs */
+#define F_SYNC_WR    (1 << 12)
+
+enum {
+        L2T_STATE_VALID,      /* entry is up to date */
+        L2T_STATE_STALE,      /* entry may be used but needs revalidation */
+        L2T_STATE_RESOLVING,  /* entry needs address resolution */
+        L2T_STATE_SYNC_WRITE, /* synchronous write of entry underway */
+
+        /* when state is one of the below the entry is not hashed */
+        L2T_STATE_SWITCHING,  /* entry is being used by a switching filter */
+        L2T_STATE_UNUSED      /* entry not in use */
+};
+
+struct l2t_data {
+        rwlock_t lock;
+        atomic_t nfree;             /* number of free entries */
+        struct l2t_entry *rover;    /* starting point for next allocation */
+        struct l2t_entry l2tab[L2T_SIZE];
+};
+
+static inline unsigned int vlan_prio(const struct l2t_entry *e)
+{
+        return e->vlan >> 13;
+}
+
+static inline void l2t_hold(struct l2t_data *d, struct l2t_entry *e)
+{
+        if (atomic_add_return(1, &e->refcnt) == 1)  /* 0 -> 1 transition */
+                atomic_dec(&d->nfree);
+}
+
+/*
+ * To avoid having to check address families we do not allow v4 and v6
+ * neighbors to be on the same hash chain.  We keep v4 entries in the first
+ * half of available hash buckets and v6 in the second.
+ */
+enum {
+        L2T_SZ_HALF = L2T_SIZE / 2,
+        L2T_HASH_MASK = L2T_SZ_HALF - 1
+};
+
+static inline unsigned int arp_hash(const u32 *key, int ifindex)
+{
+        return jhash_2words(*key, ifindex, 0) & L2T_HASH_MASK;
+}
+
+static inline unsigned int ipv6_hash(const u32 *key, int ifindex)
+{
+        u32 xor = key[0] ^ key[1] ^ key[2] ^ key[3];
+
+        return L2T_SZ_HALF + (jhash_2words(xor, ifindex, 0) & L2T_HASH_MASK);
+}
+
+static unsigned int addr_hash(const u32 *addr, int addr_len, int ifindex)
+{
+        return addr_len == 4 ? arp_hash(addr, ifindex) :
+                               ipv6_hash(addr, ifindex);
+}
+
+/*
+ * Checks if an L2T entry is for the given IP/IPv6 address.  It does not check
+ * whether the L2T entry and the address are of the same address family.
+ * Callers ensure an address is only checked against L2T entries of the same
+ * family, something made trivial by the separation of IP and IPv6 hash chains
+ * mentioned above.  Returns 0 if there's a match,
+ */
+static int addreq(const struct l2t_entry *e, const u32 *addr)
+{
+        if (e->v6)
+                return (e->addr[0] ^ addr[0]) | (e->addr[1] ^ addr[1]) |
+                       (e->addr[2] ^ addr[2]) | (e->addr[3] ^ addr[3]);
+        return e->addr[0] ^ addr[0];
+}
+
+static void neigh_replace(struct l2t_entry *e, struct neighbour *n)
+{
+        neigh_hold(n);
+        if (e->neigh)
+                neigh_release(e->neigh);
+        e->neigh = n;
+}
+
+/*
+ * Write an L2T entry.  Must be called with the entry locked.
+ * The write may be synchronous or asynchronous.
+ */
+static int write_l2e(struct adapter *adap, struct l2t_entry *e, int sync)
+{
+        struct sk_buff *skb;
+        struct cpl_l2t_write_req *req;
+
+        skb = alloc_skb(sizeof(*req), GFP_ATOMIC);
+        if (!skb)
+                return -ENOMEM;
+
+        req = (struct cpl_l2t_write_req *)__skb_put(skb, sizeof(*req));
+        INIT_TP_WR(req, 0);
+
+        OPCODE_TID(req) = htonl(MK_OPCODE_TID(CPL_L2T_WRITE_REQ,
+                                        e->idx | (sync ? F_SYNC_WR : 0) |
+                                        TID_QID(adap->sge.fw_evtq.abs_id)));
+        req->params = htons(L2T_W_PORT(e->lport) | L2T_W_NOREPLY(!sync));
+        req->l2t_idx = htons(e->idx);
+        req->vlan = htons(e->vlan);
+        if (e->neigh)
+                memcpy(e->dmac, e->neigh->ha, sizeof(e->dmac));
+        memcpy(req->dst_mac, e->dmac, sizeof(req->dst_mac));
+
+        set_wr_txq(skb, CPL_PRIORITY_CONTROL, 0);
+        t4_ofld_send(adap, skb);
+
+        if (sync && e->state != L2T_STATE_SWITCHING)
+                e->state = L2T_STATE_SYNC_WRITE;
+        return 0;
+}
+
+/*
+ * Send packets waiting in an L2T entry's ARP queue.  Must be called with the
+ * entry locked.
+ */
+static void send_pending(struct adapter *adap, struct l2t_entry *e)
+{
+        while (e->arpq_head) {
+                struct sk_buff *skb = e->arpq_head;
+
+                e->arpq_head = skb->next;
+                skb->next = NULL;
+                t4_ofld_send(adap, skb);
+        }
+        e->arpq_tail = NULL;
+}
+
+/*
+ * Process a CPL_L2T_WRITE_RPL.  Wake up the ARP queue if it completes a
+ * synchronous L2T_WRITE.  Note that the TID in the reply is really the L2T
+ * index it refers to.
+ */
+void do_l2t_write_rpl(struct adapter *adap, const struct cpl_l2t_write_rpl *rpl)
+{
+        unsigned int tid = GET_TID(rpl);
+        unsigned int idx = tid & (L2T_SIZE - 1);
+
+        if (unlikely(rpl->status != CPL_ERR_NONE)) {
+                dev_err(adap->pdev_dev,
+                        "Unexpected L2T_WRITE_RPL status %u for entry %u\n",
+                        rpl->status, idx);
+                return;
+        }
+
+        if (tid & F_SYNC_WR) {
+                struct l2t_entry *e = &adap->l2t->l2tab[idx];
+
+                spin_lock(&e->lock);
+                if (e->state != L2T_STATE_SWITCHING) {
+                        send_pending(adap, e);
+                        e->state = (e->neigh->nud_state & NUD_STALE) ?
+                                        L2T_STATE_STALE : L2T_STATE_VALID;
+                }
+                spin_unlock(&e->lock);
+        }
+}
+
+/*
+ * Add a packet to an L2T entry's queue of packets awaiting resolution.
+ * Must be called with the entry's lock held.
+ */
+static inline void arpq_enqueue(struct l2t_entry *e, struct sk_buff *skb)
+{
+        skb->next = NULL;
+        if (e->arpq_head)
+                e->arpq_tail->next = skb;
+        else
+                e->arpq_head = skb;
+        e->arpq_tail = skb;
+}
+
+int cxgb4_l2t_send(struct net_device *dev, struct sk_buff *skb,
+                   struct l2t_entry *e)
+{
+        struct adapter *adap = netdev2adap(dev);
+
+again:
+        switch (e->state) {
+        case L2T_STATE_STALE:     /* entry is stale, kick off revalidation */
+                neigh_event_send(e->neigh, NULL);
+                spin_lock_bh(&e->lock);
+                if (e->state == L2T_STATE_STALE)
+                        e->state = L2T_STATE_VALID;
+                spin_unlock_bh(&e->lock);
+        case L2T_STATE_VALID:     /* fast-path, send the packet on */
+                return t4_ofld_send(adap, skb);
+        case L2T_STATE_RESOLVING:
+        case L2T_STATE_SYNC_WRITE:
+                spin_lock_bh(&e->lock);
+                if (e->state != L2T_STATE_SYNC_WRITE &&
+                    e->state != L2T_STATE_RESOLVING) {
+                        spin_unlock_bh(&e->lock);
+                        goto again;
+                }
+                arpq_enqueue(e, skb);
+                spin_unlock_bh(&e->lock);
+
+                if (e->state == L2T_STATE_RESOLVING &&
+                    !neigh_event_send(e->neigh, NULL)) {
+                        spin_lock_bh(&e->lock);
+                        if (e->state == L2T_STATE_RESOLVING && e->arpq_head)
+                                write_l2e(adap, e, 1);
+                        spin_unlock_bh(&e->lock);
+                }
+        }
+        return 0;
+}
+EXPORT_SYMBOL(cxgb4_l2t_send);
+
+/*
+ * Allocate a free L2T entry.  Must be called with l2t_data.lock held.
+ */
+static struct l2t_entry *alloc_l2e(struct l2t_data *d)
+{
+        struct l2t_entry *end, *e, **p;
+
+        if (!atomic_read(&d->nfree))
+                return NULL;
+
+        /* there's definitely a free entry */
+        for (e = d->rover, end = &d->l2tab[L2T_SIZE]; e != end; ++e)
+                if (atomic_read(&e->refcnt) == 0)
+                        goto found;
+
+        for (e = d->l2tab; atomic_read(&e->refcnt); ++e)
+                ;
+found:
+        d->rover = e + 1;
+        atomic_dec(&d->nfree);
+
+        /*
+         * 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;
+        return e;
+}
+
+/*
+ * Called when an L2T entry has no more users.
+ */
+static void t4_l2e_free(struct l2t_entry *e)
+{
+        struct l2t_data *d;
+
+        spin_lock_bh(&e->lock);
+        if (atomic_read(&e->refcnt) == 0) {  /* hasn't been recycled */
+                if (e->neigh) {
+                        neigh_release(e->neigh);
+                        e->neigh = NULL;
+                }
+        }
+        spin_unlock_bh(&e->lock);
+
+        d = container_of(e, struct l2t_data, l2tab[e->idx]);
+        atomic_inc(&d->nfree);
+}
+
+void cxgb4_l2t_release(struct l2t_entry *e)
+{
+        if (atomic_dec_and_test(&e->refcnt))
+                t4_l2e_free(e);
+}
+EXPORT_SYMBOL(cxgb4_l2t_release);
+
+/*
+ * Update an L2T entry that was previously used for the same next hop as neigh.
+ * Must be called with softirqs disabled.
+ */
+static void reuse_entry(struct l2t_entry *e, struct neighbour *neigh)
+{
+        unsigned int nud_state;
+
+        spin_lock(&e->lock);                /* avoid race with t4_l2t_free */
+        if (neigh != e->neigh)
+                neigh_replace(e, neigh);
+        nud_state = neigh->nud_state;
+        if (memcmp(e->dmac, neigh->ha, sizeof(e->dmac)) ||
+            !(nud_state & NUD_VALID))
+                e->state = L2T_STATE_RESOLVING;
+        else if (nud_state & NUD_CONNECTED)
+                e->state = L2T_STATE_VALID;
+        else
+                e->state = L2T_STATE_STALE;
+        spin_unlock(&e->lock);
+}
+
+struct l2t_entry *cxgb4_l2t_get(struct l2t_data *d, struct neighbour *neigh,
+                                const struct net_device *physdev,
+                                unsigned int priority)
+{
+        u8 lport;
+        u16 vlan;
+        struct l2t_entry *e;
+        int addr_len = neigh->tbl->key_len;
+        u32 *addr = (u32 *)neigh->primary_key;
+        int ifidx = neigh->dev->ifindex;
+        int hash = addr_hash(addr, addr_len, ifidx);
+
+        if (neigh->dev->flags & IFF_LOOPBACK)
+                lport = netdev2pinfo(physdev)->tx_chan + 4;
+        else
+                lport = netdev2pinfo(physdev)->lport;
+
+        if (neigh->dev->priv_flags & IFF_802_1Q_VLAN)
+                vlan = vlan_dev_vlan_id(neigh->dev);
+        else
+                vlan = VLAN_NONE;
+
+        write_lock_bh(&d->lock);
+        for (e = d->l2tab[hash].first; e; e = e->next)
+                if (!addreq(e, addr) && e->ifindex == ifidx &&
+                    e->vlan == vlan && e->lport == lport) {
+                        l2t_hold(d, e);
+                        if (atomic_read(&e->refcnt) == 1)
+                                reuse_entry(e, neigh);
+                        goto done;
+                }
+
+        /* Need to allocate a new entry */
+        e = alloc_l2e(d);
+        if (e) {
+                spin_lock(&e->lock);          /* avoid race with t4_l2t_free */
+                e->state = L2T_STATE_RESOLVING;
+                memcpy(e->addr, addr, addr_len);
+                e->ifindex = ifidx;
+                e->hash = hash;
+                e->lport = lport;
+                e->v6 = addr_len == 16;
+                atomic_set(&e->refcnt, 1);
+                neigh_replace(e, neigh);
+                e->vlan = vlan;
+                e->next = d->l2tab[hash].first;
+                d->l2tab[hash].first = e;
+                spin_unlock(&e->lock);
+        }
+done:
+        write_unlock_bh(&d->lock);
+        return e;
+}
+EXPORT_SYMBOL(cxgb4_l2t_get);
+
+/*
+ * Called when address resolution fails for an L2T entry to handle packets
+ * on the arpq head.  If a packet specifies a failure handler it is invoked,
+ * otherwise the packet is sent to the device.
+ */
+static void handle_failed_resolution(struct adapter *adap, struct sk_buff *arpq)
+{
+        while (arpq) {
+                struct sk_buff *skb = arpq;
+                const struct l2t_skb_cb *cb = L2T_SKB_CB(skb);
+
+                arpq = skb->next;
+                skb->next = NULL;
+                if (cb->arp_err_handler)
+                        cb->arp_err_handler(cb->handle, skb);
+                else
+                        t4_ofld_send(adap, skb);
+        }
+}
+
+/*
+ * Called when the host's neighbor layer makes a change to some entry that is
+ * loaded into the HW L2 table.
+ */
+void t4_l2t_update(struct adapter *adap, struct neighbour *neigh)
+{
+        struct l2t_entry *e;
+        struct sk_buff *arpq = NULL;
+        struct l2t_data *d = adap->l2t;
+        int addr_len = neigh->tbl->key_len;
+        u32 *addr = (u32 *) neigh->primary_key;
+        int ifidx = neigh->dev->ifindex;
+        int hash = addr_hash(addr, addr_len, ifidx);
+
+        read_lock_bh(&d->lock);
+        for (e = d->l2tab[hash].first; e; e = e->next)
+                if (!addreq(e, addr) && e->ifindex == ifidx) {
+                        spin_lock(&e->lock);
+                        if (atomic_read(&e->refcnt))
+                                goto found;
+                        spin_unlock(&e->lock);
+                        break;
+                }
+        read_unlock_bh(&d->lock);
+        return;
+
+ found:
+        read_unlock(&d->lock);
+
+        if (neigh != e->neigh)
+                neigh_replace(e, neigh);
+
+        if (e->state == L2T_STATE_RESOLVING) {
+                if (neigh->nud_state & NUD_FAILED) {
+                        arpq = e->arpq_head;
+                        e->arpq_head = e->arpq_tail = NULL;
+                } else if ((neigh->nud_state & (NUD_CONNECTED | NUD_STALE)) &&
+                           e->arpq_head) {
+                        write_l2e(adap, e, 1);
+                }
+        } else {
+                e->state = neigh->nud_state & NUD_CONNECTED ?
+                        L2T_STATE_VALID : L2T_STATE_STALE;
+                if (memcmp(e->dmac, neigh->ha, sizeof(e->dmac)))
+                        write_l2e(adap, e, 0);
+        }
+
+        spin_unlock_bh(&e->lock);
+
+        if (arpq)
+                handle_failed_resolution(adap, arpq);
+}
+
+/*
+ * Allocate an L2T entry for use by a switching rule.  Such entries need to be
+ * 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 *e;
+
+        write_lock_bh(&d->lock);
+        e = alloc_l2e(d);
+        if (e) {
+                spin_lock(&e->lock);          /* avoid race with t4_l2t_free */
+                e->state = L2T_STATE_SWITCHING;
+                atomic_set(&e->refcnt, 1);
+                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.
+ */
+int t4_l2t_set_switching(struct adapter *adap, struct l2t_entry *e, u16 vlan,
+                         u8 port, u8 *eth_addr)
+{
+        e->vlan = vlan;
+        e->lport = port;
+        memcpy(e->dmac, eth_addr, ETH_ALEN);
+        return write_l2e(adap, e, 0);
+}
+
+struct l2t_data *t4_init_l2t(void)
+{
+        int i;
+        struct l2t_data *d;
+
+        d = t4_alloc_mem(sizeof(*d));
+        if (!d)
+                return NULL;
+
+        d->rover = d->l2tab;
+        atomic_set(&d->nfree, L2T_SIZE);
+        rwlock_init(&d->lock);
+
+        for (i = 0; i < L2T_SIZE; ++i) {
+                d->l2tab[i].idx = i;
+                d->l2tab[i].state = L2T_STATE_UNUSED;
+                spin_lock_init(&d->l2tab[i].lock);
+                atomic_set(&d->l2tab[i].refcnt, 0);
+        }
+        return d;
+}
+
+#include <linux/module.h>
+#include <linux/debugfs.h>
+#include <linux/seq_file.h>
+
+static inline void *l2t_get_idx(struct seq_file *seq, loff_t pos)
+{
+        struct l2t_entry *l2tab = seq->private;
+
+        return pos >= L2T_SIZE ? NULL : &l2tab[pos];
+}
+
+static void *l2t_seq_start(struct seq_file *seq, loff_t *pos)
+{
+        return *pos ? l2t_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
+}
+
+static void *l2t_seq_next(struct seq_file *seq, void *v, loff_t *pos)
+{
+        v = l2t_get_idx(seq, *pos);
+        if (v)
+                ++*pos;
+        return v;
+}
+
+static void l2t_seq_stop(struct seq_file *seq, void *v)
+{
+}
+
+static char l2e_state(const struct l2t_entry *e)
+{
+        switch (e->state) {
+        case L2T_STATE_VALID: return 'V';
+        case L2T_STATE_STALE: return 'S';
+        case L2T_STATE_SYNC_WRITE: return 'W';
+        case L2T_STATE_RESOLVING: return e->arpq_head ? 'A' : 'R';
+        case L2T_STATE_SWITCHING: return 'X';
+        default:
+                return 'U';
+        }
+}
+
+static int l2t_seq_show(struct seq_file *seq, void *v)
+{
+        if (v == SEQ_START_TOKEN)
+                seq_puts(seq, " Idx IP address                "
+                         "Ethernet address  VLAN/P LP State Users Port\n");
+        else {
+                char ip[60];
+                struct l2t_entry *e = v;
+
+                spin_lock_bh(&e->lock);
+                if (e->state == L2T_STATE_SWITCHING)
+                        ip[0] = '\0';
+                else
+                        sprintf(ip, e->v6 ? "%pI6c" : "%pI4", e->addr);
+                seq_printf(seq, "%4u %-25s %17pM %4d %u %2u   %c   %5u %s\n",
+                           e->idx, ip, e->dmac,
+                           e->vlan & VLAN_VID_MASK, vlan_prio(e), e->lport,
+                           l2e_state(e), atomic_read(&e->refcnt),
+                           e->neigh ? e->neigh->dev->name : "");
+                spin_unlock_bh(&e->lock);
+        }
+        return 0;
+}
+
+static const struct seq_operations l2t_seq_ops = {
+        .start = l2t_seq_start,
+        .next = l2t_seq_next,
+        .stop = l2t_seq_stop,
+        .show = l2t_seq_show
+};
+
+static int l2t_seq_open(struct inode *inode, struct file *file)
+{
+        int rc = seq_open(file, &l2t_seq_ops);
+
+        if (!rc) {
+                struct adapter *adap = inode->i_private;
+                struct seq_file *seq = file->private_data;
+
+                seq->private = adap->l2t->l2tab;
+        }
+        return rc;
+}
+
+const struct file_operations t4_l2t_fops = {
+        .owner = THIS_MODULE,
+        .open = l2t_seq_open,
+        .read = seq_read,
+        .llseek = seq_lseek,
+        .release = seq_release,
+};