Merge tag 'rpmsg-v4.9' of git://github.com/andersson/remoteproc
[cascardo/linux.git] / net / tipc / link.c
index 877d94f..b36e16c 100644 (file)
@@ -181,7 +181,10 @@ struct tipc_link {
        u16 acked;
        struct tipc_link *bc_rcvlink;
        struct tipc_link *bc_sndlink;
-       int nack_state;
+       unsigned long prev_retr;
+       u16 prev_from;
+       u16 prev_to;
+       u8 nack_state;
        bool bc_peer_is_up;
 
        /* Statistics */
@@ -202,6 +205,8 @@ enum {
        BC_NACK_SND_SUPPRESS,
 };
 
+#define TIPC_BC_RETR_LIMIT 10   /* [ms] */
+
 /*
  * Interval between NACKs when packets arrive out of order
  */
@@ -237,8 +242,8 @@ static void tipc_link_build_proto_msg(struct tipc_link *l, int mtyp, bool probe,
                                      u16 rcvgap, int tolerance, int priority,
                                      struct sk_buff_head *xmitq);
 static void link_print(struct tipc_link *l, const char *str);
-static void tipc_link_build_nack_msg(struct tipc_link *l,
-                                    struct sk_buff_head *xmitq);
+static int tipc_link_build_nack_msg(struct tipc_link *l,
+                                   struct sk_buff_head *xmitq);
 static void tipc_link_build_bc_init_msg(struct tipc_link *l,
                                        struct sk_buff_head *xmitq);
 static bool tipc_link_release_pkts(struct tipc_link *l, u16 to);
@@ -367,6 +372,18 @@ int tipc_link_bc_peers(struct tipc_link *l)
        return l->ackers;
 }
 
+u16 link_bc_rcv_gap(struct tipc_link *l)
+{
+       struct sk_buff *skb = skb_peek(&l->deferdq);
+       u16 gap = 0;
+
+       if (more(l->snd_nxt, l->rcv_nxt))
+               gap = l->snd_nxt - l->rcv_nxt;
+       if (skb)
+               gap = buf_seqno(skb) - l->rcv_nxt;
+       return gap;
+}
+
 void tipc_link_set_mtu(struct tipc_link *l, int mtu)
 {
        l->mtu = mtu;
@@ -807,7 +824,7 @@ void link_prepare_wakeup(struct tipc_link *l)
 
        skb_queue_walk_safe(&l->wakeupq, skb, tmp) {
                imp = TIPC_SKB_CB(skb)->chain_imp;
-               lim = l->window + l->backlog[imp].limit;
+               lim = l->backlog[imp].limit;
                pnd[imp] += TIPC_SKB_CB(skb)->chain_sz;
                if ((pnd[imp] + l->backlog[imp].len) >= lim)
                        break;
@@ -873,9 +890,11 @@ int tipc_link_xmit(struct tipc_link *l, struct sk_buff_head *list,
        struct sk_buff *skb, *_skb, *bskb;
 
        /* Match msg importance against this and all higher backlog limits: */
-       for (i = imp; i <= TIPC_SYSTEM_IMPORTANCE; i++) {
-               if (unlikely(l->backlog[i].len >= l->backlog[i].limit))
-                       return link_schedule_user(l, list);
+       if (!skb_queue_empty(backlogq)) {
+               for (i = imp; i <= TIPC_SYSTEM_IMPORTANCE; i++) {
+                       if (unlikely(l->backlog[i].len >= l->backlog[i].limit))
+                               return link_schedule_user(l, list);
+               }
        }
        if (unlikely(msg_size(hdr) > mtu)) {
                skb_queue_purge(list);
@@ -1133,7 +1152,10 @@ int tipc_link_build_state_msg(struct tipc_link *l, struct sk_buff_head *xmitq)
                if (((l->rcv_nxt ^ tipc_own_addr(l->net)) & 0xf) != 0xf)
                        return 0;
                l->rcv_unacked = 0;
-               return TIPC_LINK_SND_BC_ACK;
+
+               /* Use snd_nxt to store peer's snd_nxt in broadcast rcv link */
+               l->snd_nxt = l->rcv_nxt;
+               return TIPC_LINK_SND_STATE;
        }
 
        /* Unicast ACK */
@@ -1162,17 +1184,26 @@ void tipc_link_build_reset_msg(struct tipc_link *l, struct sk_buff_head *xmitq)
 }
 
 /* tipc_link_build_nack_msg: prepare link nack message for transmission
+ * Note that sending of broadcast NACK is coordinated among nodes, to
+ * reduce the risk of NACK storms towards the sender
  */
-static void tipc_link_build_nack_msg(struct tipc_link *l,
-                                    struct sk_buff_head *xmitq)
+static int tipc_link_build_nack_msg(struct tipc_link *l,
+                                   struct sk_buff_head *xmitq)
 {
        u32 def_cnt = ++l->stats.deferred_recv;
+       int match1, match2;
 
-       if (link_is_bc_rcvlink(l))
-               return;
+       if (link_is_bc_rcvlink(l)) {
+               match1 = def_cnt & 0xf;
+               match2 = tipc_own_addr(l->net) & 0xf;
+               if (match1 == match2)
+                       return TIPC_LINK_SND_STATE;
+               return 0;
+       }
 
        if ((skb_queue_len(&l->deferdq) == 1) || !(def_cnt % TIPC_NACK_INTV))
                tipc_link_build_proto_msg(l, STATE_MSG, 0, 0, 0, 0, xmitq);
+       return 0;
 }
 
 /* tipc_link_rcv - process TIPC packets/messages arriving from off-node
@@ -1223,7 +1254,7 @@ int tipc_link_rcv(struct tipc_link *l, struct sk_buff *skb,
                /* Defer delivery if sequence gap */
                if (unlikely(seqno != rcv_nxt)) {
                        __tipc_skb_queue_sorted(defq, seqno, skb);
-                       tipc_link_build_nack_msg(l, xmitq);
+                       rc |= tipc_link_build_nack_msg(l, xmitq);
                        break;
                }
 
@@ -1234,7 +1265,7 @@ int tipc_link_rcv(struct tipc_link *l, struct sk_buff *skb,
                        rc |= tipc_link_input(l, skb, l->inputq);
                if (unlikely(++l->rcv_unacked >= TIPC_MIN_LINK_WIN))
                        rc |= tipc_link_build_state_msg(l, xmitq);
-               if (unlikely(rc & ~TIPC_LINK_SND_BC_ACK))
+               if (unlikely(rc & ~TIPC_LINK_SND_STATE))
                        break;
        } while ((skb = __skb_dequeue(defq)));
 
@@ -1248,10 +1279,11 @@ static void tipc_link_build_proto_msg(struct tipc_link *l, int mtyp, bool probe,
                                      u16 rcvgap, int tolerance, int priority,
                                      struct sk_buff_head *xmitq)
 {
+       struct tipc_link *bcl = l->bc_rcvlink;
        struct sk_buff *skb;
        struct tipc_msg *hdr;
        struct sk_buff_head *dfq = &l->deferdq;
-       bool node_up = link_is_up(l->bc_rcvlink);
+       bool node_up = link_is_up(bcl);
        struct tipc_mon_state *mstate = &l->mon_state;
        int dlen = 0;
        void *data;
@@ -1279,7 +1311,7 @@ static void tipc_link_build_proto_msg(struct tipc_link *l, int mtyp, bool probe,
        msg_set_net_plane(hdr, l->net_plane);
        msg_set_next_sent(hdr, l->snd_nxt);
        msg_set_ack(hdr, l->rcv_nxt - 1);
-       msg_set_bcast_ack(hdr, l->bc_rcvlink->rcv_nxt - 1);
+       msg_set_bcast_ack(hdr, bcl->rcv_nxt - 1);
        msg_set_last_bcast(hdr, l->bc_sndlink->snd_nxt - 1);
        msg_set_link_tolerance(hdr, tolerance);
        msg_set_linkprio(hdr, priority);
@@ -1289,6 +1321,7 @@ static void tipc_link_build_proto_msg(struct tipc_link *l, int mtyp, bool probe,
 
        if (mtyp == STATE_MSG) {
                msg_set_seq_gap(hdr, rcvgap);
+               msg_set_bc_gap(hdr, link_bc_rcv_gap(bcl));
                msg_set_probe(hdr, probe);
                tipc_mon_prep(l->net, data, &dlen, mstate, l->bearer_id);
                msg_set_size(hdr, INT_H_SIZE + dlen);
@@ -1571,51 +1604,107 @@ void tipc_link_bc_init_rcv(struct tipc_link *l, struct tipc_msg *hdr)
                l->rcv_nxt = peers_snd_nxt;
 }
 
+/* link_bc_retr eval()- check if the indicated range can be retransmitted now
+ * - Adjust permitted range if there is overlap with previous retransmission
+ */
+static bool link_bc_retr_eval(struct tipc_link *l, u16 *from, u16 *to)
+{
+       unsigned long elapsed = jiffies_to_msecs(jiffies - l->prev_retr);
+
+       if (less(*to, *from))
+               return false;
+
+       /* New retransmission request */
+       if ((elapsed > TIPC_BC_RETR_LIMIT) ||
+           less(*to, l->prev_from) || more(*from, l->prev_to)) {
+               l->prev_from = *from;
+               l->prev_to = *to;
+               l->prev_retr = jiffies;
+               return true;
+       }
+
+       /* Inside range of previous retransmit */
+       if (!less(*from, l->prev_from) && !more(*to, l->prev_to))
+               return false;
+
+       /* Fully or partially outside previous range => exclude overlap */
+       if (less(*from, l->prev_from)) {
+               *to = l->prev_from - 1;
+               l->prev_from = *from;
+       }
+       if (more(*to, l->prev_to)) {
+               *from = l->prev_to + 1;
+               l->prev_to = *to;
+       }
+       l->prev_retr = jiffies;
+       return true;
+}
+
 /* tipc_link_bc_sync_rcv - update rcv link according to peer's send state
  */
-void tipc_link_bc_sync_rcv(struct tipc_link *l, struct tipc_msg *hdr,
-                          struct sk_buff_head *xmitq)
+int tipc_link_bc_sync_rcv(struct tipc_link *l, struct tipc_msg *hdr,
+                         struct sk_buff_head *xmitq)
 {
+       struct tipc_link *snd_l = l->bc_sndlink;
        u16 peers_snd_nxt = msg_bc_snd_nxt(hdr);
+       u16 from = msg_bcast_ack(hdr) + 1;
+       u16 to = from + msg_bc_gap(hdr) - 1;
+       int rc = 0;
 
        if (!link_is_up(l))
-               return;
+               return rc;
 
        if (!msg_peer_node_is_up(hdr))
-               return;
+               return rc;
 
        /* Open when peer ackowledges our bcast init msg (pkt #1) */
        if (msg_ack(hdr))
                l->bc_peer_is_up = true;
 
        if (!l->bc_peer_is_up)
-               return;
+               return rc;
+
+       l->stats.recv_nacks++;
 
        /* Ignore if peers_snd_nxt goes beyond receive window */
        if (more(peers_snd_nxt, l->rcv_nxt + l->window))
-               return;
+               return rc;
+
+       if (link_bc_retr_eval(snd_l, &from, &to))
+               rc = tipc_link_retrans(snd_l, from, to, xmitq);
+
+       l->snd_nxt = peers_snd_nxt;
+       if (link_bc_rcv_gap(l))
+               rc |= TIPC_LINK_SND_STATE;
+
+       /* Return now if sender supports nack via STATE messages */
+       if (l->peer_caps & TIPC_BCAST_STATE_NACK)
+               return rc;
+
+       /* Otherwise, be backwards compatible */
 
        if (!more(peers_snd_nxt, l->rcv_nxt)) {
                l->nack_state = BC_NACK_SND_CONDITIONAL;
-               return;
+               return 0;
        }
 
        /* Don't NACK if one was recently sent or peeked */
        if (l->nack_state == BC_NACK_SND_SUPPRESS) {
                l->nack_state = BC_NACK_SND_UNCONDITIONAL;
-               return;
+               return 0;
        }
 
        /* Conditionally delay NACK sending until next synch rcv */
        if (l->nack_state == BC_NACK_SND_CONDITIONAL) {
                l->nack_state = BC_NACK_SND_UNCONDITIONAL;
                if ((peers_snd_nxt - l->rcv_nxt) < TIPC_MIN_LINK_WIN)
-                       return;
+                       return 0;
        }
 
        /* Send NACK now but suppress next one */
        tipc_link_build_bc_proto_msg(l, true, peers_snd_nxt, xmitq);
        l->nack_state = BC_NACK_SND_SUPPRESS;
+       return 0;
 }
 
 void tipc_link_bc_ack_rcv(struct tipc_link *l, u16 acked,
@@ -1652,6 +1741,8 @@ void tipc_link_bc_ack_rcv(struct tipc_link *l, u16 acked,
 }
 
 /* tipc_link_bc_nack_rcv(): receive broadcast nack message
+ * This function is here for backwards compatibility, since
+ * no BCAST_PROTOCOL/STATE messages occur from TIPC v2.5.
  */
 int tipc_link_bc_nack_rcv(struct tipc_link *l, struct sk_buff *skb,
                          struct sk_buff_head *xmitq)
@@ -1692,10 +1783,10 @@ void tipc_link_set_queue_limits(struct tipc_link *l, u32 win)
        int max_bulk = TIPC_MAX_PUBLICATIONS / (l->mtu / ITEM_SIZE);
 
        l->window = win;
-       l->backlog[TIPC_LOW_IMPORTANCE].limit      = win / 2;
-       l->backlog[TIPC_MEDIUM_IMPORTANCE].limit   = win;
-       l->backlog[TIPC_HIGH_IMPORTANCE].limit     = win / 2 * 3;
-       l->backlog[TIPC_CRITICAL_IMPORTANCE].limit = win * 2;
+       l->backlog[TIPC_LOW_IMPORTANCE].limit      = max_t(u16, 50, win);
+       l->backlog[TIPC_MEDIUM_IMPORTANCE].limit   = max_t(u16, 100, win * 2);
+       l->backlog[TIPC_HIGH_IMPORTANCE].limit     = max_t(u16, 150, win * 3);
+       l->backlog[TIPC_CRITICAL_IMPORTANCE].limit = max_t(u16, 200, win * 4);
        l->backlog[TIPC_SYSTEM_IMPORTANCE].limit   = max_bulk;
 }