net/smc: urgent data support

Add support for out of band data send and receive.

Signed-off-by: Stefan Raspl <raspl@linux.ibm.com>
Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 13 insertions, 0 deletions

diff --git a/net/smc/smc_cdc.h b/net/smc/smc_cdc.h
index d2012fd..f60082f 100644
--- a/net/smc/smc_cdc.h
+++ b/net/smc/smc_cdc.h
@@ -146,6 +146,19 @@ static inline int smc_curs_diff(unsigned int size,
 	return max_t(int, 0, (new->count - old->count));
 }
 
+/* calculate cursor difference between old and new - returns negative
+ * value in case old > new
+ */
+static inline int smc_curs_comp(unsigned int size,
+				union smc_host_cursor *old,
+				union smc_host_cursor *new)
+{
+	if (old->wrap > new->wrap ||
+	    (old->wrap == new->wrap && old->count > new->count))
+		return -smc_curs_diff(size, new, old);
+	return smc_curs_diff(size, old, new);
+}
+
 static inline void smc_host_cursor_to_cdc(union smc_cdc_cursor *peer,
 					  union smc_host_cursor *local,
 					  struct smc_connection *conn)