Start process of removing the use of the deprecated "M_FLOWID" flag

from the FreeBSD network code. The flag is still kept around in the
"sys/mbuf.h" header file, but does no longer have any users. Instead
the "m_pkthdr.rsstype" field in the mbuf structure is now used to
decide the meaning of the "m_pkthdr.flowid" field. To modify the
"m_pkthdr.rsstype" field please use the existing "M_HASHTYPE_XXX"
macros as defined in the "sys/mbuf.h" header file.

This patch introduces new behaviour in the transmit direction.
Previously network drivers checked if "M_FLOWID" was set in "m_flags"
before using the "m_pkthdr.flowid" field. This check has now now been
replaced by checking if "M_HASHTYPE_GET(m)" is different from
"M_HASHTYPE_NONE". In the future more hashtypes will be added, for
example hashtypes for hardware dedicated flows.

"M_HASHTYPE_OPAQUE" indicates that the "m_pkthdr.flowid" value is
valid and has no particular type. This change removes the need for an
"if" statement in TCP transmit code checking for the presence of a
valid flowid value. The "if" statement mentioned above is now a direct
variable assignment which is then later checked by the respective
network drivers like before.

Additional notes:
- The SCTP code changes will be committed as a separate patch.
- Removal of the "M_FLOWID" flag will also be done separately.
- The FreeBSD version has been bumped.

MFC after:	1 month
Sponsored by:	Mellanox Technologies

1 files changed, 4 insertions, 5 deletions

diff --git a/sys/dev/bxe/bxe.c b/sys/dev/bxe/bxe.c
index a27b3e7..3509f2d 100644
--- a/sys/dev/bxe/bxe.c
+++ b/sys/dev/bxe/bxe.c
@@ -3219,7 +3219,7 @@ bxe_tpa_stop(struct bxe_softc          *sc,
 #if __FreeBSD_version >= 800000
         /* specify what RSS queue was used for this flow */
         m->m_pkthdr.flowid = fp->index;
-        m->m_flags |= M_FLOWID;
+        M_HASHTYPE_SET(m, M_HASHTYPE_OPAQUE);
 #endif
 
         if_inc_counter(ifp, IFCOUNTER_IPACKETS, 1);
@@ -3454,7 +3454,7 @@ bxe_rxeof(struct bxe_softc    *sc,
 #if __FreeBSD_version >= 800000
         /* specify what RSS queue was used for this flow */
         m->m_pkthdr.flowid = fp->index;
-        m->m_flags |= M_FLOWID;
+        M_HASHTYPE_SET(m, M_HASHTYPE_OPAQUE);
 #endif
 
 next_rx:
@@ -6037,10 +6037,9 @@ bxe_tx_mq_start(struct ifnet *ifp,
 
     fp_index = 0; /* default is the first queue */
 
-    /* change the queue if using flow ID */
-    if ((m->m_flags & M_FLOWID) != 0) {
+    /* check if flowid is set */
+    if (M_HASHTYPE_GET(m) != M_HASHTYPE_NONE)
         fp_index = (m->m_pkthdr.flowid % sc->num_queues);
-    }
 
     fp = &sc->fp[fp_index];