[CCID2]: Replace pipe assignment-function with assignment

The function ccid2_change_pipe only does an assignment. This patch simplifies the code by
replacing the function with the assignment it performs.

Furthermore, the type of pipe is promoted from `signed' to unsigned (increasing the range).
As a result, a BUG_ON test for negative values now becomes obsolete (for safety not removed,
but replaced with a less annoying `DCCP_BUG').

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: Ian McDonald <ian.mcdonald@jandi.co.nz>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 8 insertions, 11 deletions

diff --git a/net/dccp/ccids/ccid2.c b/net/dccp/ccids/ccid2.c
index 747fa1c4e42e..237007bb55a8 100644
--- a/net/dccp/ccids/ccid2.c
+++ b/net/dccp/ccids/ccid2.c
@@ -171,11 +171,6 @@ static void ccid2_change_srtt(struct ccid2_hc_tx_sock *hctx, long val)
         hctx->ccid2hctx_srtt = val;
 }
 
-static void ccid2_change_pipe(struct ccid2_hc_tx_sock *hctx, long val)
-{
-        hctx->ccid2hctx_pipe = val;
-}
-
 static void ccid2_start_rto_timer(struct sock *sk);
 
 static void ccid2_hc_tx_rto_expire(unsigned long data)
@@ -205,11 +200,11 @@ static void ccid2_hc_tx_rto_expire(unsigned long data)
         ccid2_start_rto_timer(sk);
 
         /* adjust pipe, cwnd etc */
-        ccid2_change_pipe(hctx, 0);
         hctx->ccid2hctx_ssthresh = hctx->ccid2hctx_cwnd / 2;
         if (hctx->ccid2hctx_ssthresh < 2)
                 hctx->ccid2hctx_ssthresh = 2;
         hctx->ccid2hctx_cwnd     = 1;
+        hctx->ccid2hctx_pipe     = 0;
 
         /* clear state about stuff we sent */
         hctx->ccid2hctx_seqt    = hctx->ccid2hctx_seqh;
@@ -248,8 +243,7 @@ static void ccid2_hc_tx_packet_sent(struct sock *sk, int more, unsigned int len)
 
         BUG_ON(!hctx->ccid2hctx_sendwait);
         hctx->ccid2hctx_sendwait = 0;
-        ccid2_change_pipe(hctx, hctx->ccid2hctx_pipe + 1);
-        BUG_ON(hctx->ccid2hctx_pipe < 0);
+        hctx->ccid2hctx_pipe++;
 
         /* There is an issue.  What if another packet is sent between
          * packet_send() and packet_sent().  Then the sequence number would be
@@ -519,8 +513,10 @@ static void ccid2_hc_tx_dec_pipe(struct sock *sk)
 {
         struct ccid2_hc_tx_sock *hctx = ccid2_hc_tx_sk(sk);
 
-        ccid2_change_pipe(hctx, hctx->ccid2hctx_pipe-1);
-        BUG_ON(hctx->ccid2hctx_pipe < 0);
+        if (hctx->ccid2hctx_pipe == 0)
+                DCCP_BUG("pipe == 0");
+        else
+                hctx->ccid2hctx_pipe--;
 
         if (hctx->ccid2hctx_pipe == 0)
                 ccid2_hc_tx_kill_rto_timer(sk);
diff --git a/net/dccp/ccids/ccid2.h b/net/dccp/ccids/ccid2.h
index b72e9556a155..bc659f00cb96 100644
--- a/net/dccp/ccids/ccid2.h
+++ b/net/dccp/ccids/ccid2.h
@@ -42,6 +42,7 @@ struct ccid2_seq {
 
 /** struct ccid2_hc_tx_sock - CCID2 TX half connection
  *
+ * @ccid2hctx_{cwnd,ssthresh,pipe}: as per RFC 4341, section 5
  * @ccid2hctx_ssacks - ACKs recv in slow start
  * @ccid2hctx_acks - ACKS recv in AI phase
  * @ccid2hctx_lastrtt -time RTT was last measured
@@ -51,9 +52,9 @@ struct ccid2_seq {
 struct ccid2_hc_tx_sock {
         u32                     ccid2hctx_cwnd;
         u32                     ccid2hctx_ssthresh;
+        u32                     ccid2hctx_pipe;
         int                     ccid2hctx_ssacks;
         int                     ccid2hctx_acks;
-        int                     ccid2hctx_pipe;
         struct ccid2_seq        *ccid2hctx_seqbuf[CCID2_SEQBUF_MAX];
         int                     ccid2hctx_seqbufc;
         struct ccid2_seq        *ccid2hctx_seqh;