svn commit: r339749 - head/sys/dev/cxgbe

[Navdeep Parhar]

Author: np
Date: Thu Oct 25 22:55:18 2018
New Revision: 339749
URL: https://svnweb.freebsd.org/changeset/base/339749

Log:
  cxgbe(4): Add a knob to split the rx queues for a netmap enabled
  interface into two groups.  Filters can be used to match traffic
  and distribute it across a group.
  
  hw.cxgbe.nm_split_rss
  
  Sponsored by:	Chelsio Communications

Modified:
  head/sys/dev/cxgbe/t4_netmap.c

Modified: head/sys/dev/cxgbe/t4_netmap.c
==============================================================================
--- head/sys/dev/cxgbe/t4_netmap.c	Thu Oct 25 22:16:34 2018	(r339748)
+++ head/sys/dev/cxgbe/t4_netmap.c	Thu Oct 25 22:55:18 2018	(r339749)
@@ -101,6 +101,15 @@ int lazy_tx_credit_flush = 1;
 SYSCTL_INT(_hw_cxgbe, OID_AUTO, lazy_tx_credit_flush, CTLFLAG_RWTUN,
     &lazy_tx_credit_flush, 0, "lazy credit flush for netmap tx queues.");
 
+/*
+ * Split the netmap rx queues into two groups that populate separate halves of
+ * the RSS indirection table.  This allows filters with hashmask to steer to a
+ * particular group of queues.
+ */
+static int nm_split_rss = 0;
+SYSCTL_INT(_hw_cxgbe, OID_AUTO, nm_split_rss, CTLFLAG_RWTUN,
+    &nm_split_rss, 0, "Split the netmap rx queues into two groups.");
+
 static int
 alloc_nm_rxq_hwq(struct vi_info *vi, struct sge_nm_rxq *nm_rxq, int cong)
 {
@@ -333,7 +342,7 @@ cxgbe_netmap_on(struct adapter *sc, struct vi_info *vi
 	struct netmap_kring *kring;
 	struct sge_nm_rxq *nm_rxq;
 	struct sge_nm_txq *nm_txq;
-	int rc, i, j, hwidx;
+	int rc, i, j, hwidx, defq, nrssq;
 	struct hw_buf_info *hwb;
 
 	ASSERT_SYNCHRONIZED_OP(sc);
@@ -403,20 +412,69 @@ cxgbe_netmap_on(struct adapter *sc, struct vi_info *vi
 		vi->nm_rss = malloc(vi->rss_size * sizeof(uint16_t), M_CXGBE,
 		    M_ZERO | M_WAITOK);
 	}
-	for (i = 0; i < vi->rss_size;) {
-		for_each_nm_rxq(vi, j, nm_rxq) {
-			vi->nm_rss[i++] = nm_rxq->iq_abs_id;
-			if (i == vi->rss_size)
-				break;
+
+	MPASS(vi->nnmrxq > 0);
+	if (nm_split_rss == 0 || vi->nnmrxq == 1) {
+		for (i = 0; i < vi->rss_size;) {
+			for_each_nm_rxq(vi, j, nm_rxq) {
+				vi->nm_rss[i++] = nm_rxq->iq_abs_id;
+				if (i == vi->rss_size)
+					break;
+			}
 		}
+		defq = vi->nm_rss[0];
+	} else {
+		/* We have multiple queues and we want to split the table. */
+		MPASS(nm_split_rss != 0);
+		MPASS(vi->nnmrxq > 1);
+
+		nm_rxq = &sc->sge.nm_rxq[vi->first_nm_rxq];
+		nrssq = vi->nnmrxq;
+		if (vi->nnmrxq & 1) {
+			/*
+			 * Odd number of queues. The first rxq is designated the
+			 * default queue, the rest are split evenly.
+			 */
+			defq = nm_rxq->iq_abs_id;
+			nm_rxq++;
+			nrssq--;
+		} else {
+			/*
+			 * Even number of queues split into two halves.  The
+			 * first rxq in one of the halves is designated the
+			 * default queue.
+			 */
+#if 1
+			/* First rxq in the first half. */
+			defq = nm_rxq->iq_abs_id;
+#else
+			/* First rxq in the second half. */
+			defq = nm_rxq[vi->nnmrxq / 2].iq_abs_id;
+#endif
+		}
+
+		i = 0;
+		while (i < vi->rss_size / 2) {
+			for (j = 0; j < nrssq / 2; j++) {
+				vi->nm_rss[i++] = nm_rxq[j].iq_abs_id;
+				if (i == vi->rss_size / 2)
+					break;
+			}
+		}
+		while (i < vi->rss_size) {
+			for (j = nrssq / 2; j < nrssq; j++) {
+				vi->nm_rss[i++] = nm_rxq[j].iq_abs_id;
+				if (i == vi->rss_size)
+					break;
+			}
+		}
 	}
 	rc = -t4_config_rss_range(sc, sc->mbox, vi->viid, 0, vi->rss_size,
 	    vi->nm_rss, vi->rss_size);
 	if (rc != 0)
 		if_printf(ifp, "netmap rss_config failed: %d\n", rc);
 
-	rc = -t4_config_vi_rss(sc, sc->mbox, vi->viid, vi->hashen,
-	    vi->nm_rss[0], 0, 0);
+	rc = -t4_config_vi_rss(sc, sc->mbox, vi->viid, vi->hashen, defq, 0, 0);
 	if (rc != 0)
 		if_printf(ifp, "netmap rss hash/defaultq config failed: %d\n", rc);