Merge branch 'omap-pool'

[linux-2.6-omap-h63xx.git] / net / rds / iw_recv.c

diff --git a/net/rds/iw_recv.c b/net/rds/iw_recv.c
index a1931f0027a256401a12816f25f321071c23bc92..fde470fa50d5457c72226d0336e00aeed8df534d 100644 (file)
--- a/net/rds/iw_recv.c
+++ b/net/rds/iw_recv.c
@@ -395,10 +395,37 @@ void rds_iw_recv_init_ack(struct rds_iw_connection *ic)
  * room for it beyond the ring size.  Send completion notices its special
  * wr_id and avoids working with the ring in that case.
  */
+#ifndef KERNEL_HAS_ATOMIC64
 static void rds_iw_set_ack(struct rds_iw_connection *ic, u64 seq,
                                int ack_required)
 {
-       rds_iw_set_64bit(&ic->i_ack_next, seq);
+       unsigned long flags;
+
+       spin_lock_irqsave(&ic->i_ack_lock, flags);
+       ic->i_ack_next = seq;
+       if (ack_required)
+               set_bit(IB_ACK_REQUESTED, &ic->i_ack_flags);
+       spin_unlock_irqrestore(&ic->i_ack_lock, flags);
+}
+
+static u64 rds_iw_get_ack(struct rds_iw_connection *ic)
+{
+       unsigned long flags;
+       u64 seq;
+
+       clear_bit(IB_ACK_REQUESTED, &ic->i_ack_flags);
+
+       spin_lock_irqsave(&ic->i_ack_lock, flags);
+       seq = ic->i_ack_next;
+       spin_unlock_irqrestore(&ic->i_ack_lock, flags);
+
+       return seq;
+}
+#else
+static void rds_iw_set_ack(struct rds_iw_connection *ic, u64 seq,
+                               int ack_required)
+{
+       atomic64_set(&ic->i_ack_next, seq);
        if (ack_required) {
                smp_mb__before_clear_bit();
                set_bit(IB_ACK_REQUESTED, &ic->i_ack_flags);
@@ -410,8 +437,10 @@ static u64 rds_iw_get_ack(struct rds_iw_connection *ic)
        clear_bit(IB_ACK_REQUESTED, &ic->i_ack_flags);
        smp_mb__after_clear_bit();
 
-       return ic->i_ack_next;
+       return atomic64_read(&ic->i_ack_next);
 }
+#endif
+
 
 static void rds_iw_send_ack(struct rds_iw_connection *ic, unsigned int adv_credits)
 {
@@ -464,6 +493,10 @@ static void rds_iw_send_ack(struct rds_iw_connection *ic, unsigned int adv_credi
  *  -  i_ack_next, which is the last sequence number we received
  *
  * Potentially, send queue and receive queue handlers can run concurrently.
+ * It would be nice to not have to use a spinlock to synchronize things,
+ * but the one problem that rules this out is that 64bit updates are
+ * not atomic on all platforms. Things would be a lot simpler if
+ * we had atomic64 or maybe cmpxchg64 everywhere.
  *
  * Reconnecting complicates this picture just slightly. When we
  * reconnect, we may be seeing duplicate packets. The peer