svn commit: r366247 - head/sys/dev/cxgbe

[Navdeep Parhar]

Author: np
Date: Tue Sep 29 09:25:52 2020
New Revision: 366247
URL: https://svnweb.freebsd.org/changeset/base/366247

Log:
  cxgbe(4): Avoid unnecessary work in the firmware during netmap tx.
  
  Bind the netmap tx queues to a special '0xff' scheduling class which
  makes the firmware skip some processing related to rate limiting on the
  outgoing traffic.  Future firmwares will do this automatically.
  
  MFC after:	1 week
  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	Tue Sep 29 09:11:51 2020	(r366246)
+++ head/sys/dev/cxgbe/t4_netmap.c	Tue Sep 29 09:25:52 2020	(r366247)
@@ -329,6 +329,22 @@ alloc_nm_txq_hwq(struct vi_info *vi, struct sge_nm_txq
 		nm_txq->udb = (volatile void *)udb;
 	}
 
+	if (sc->params.fw_vers < FW_VERSION32(1, 25, 1, 0)) {
+		uint32_t param, val;
+
+		param = V_FW_PARAMS_MNEM(FW_PARAMS_MNEM_DMAQ) |
+		    V_FW_PARAMS_PARAM_X(FW_PARAMS_PARAM_DMAQ_EQ_SCHEDCLASS_ETH) |
+		    V_FW_PARAMS_PARAM_YZ(nm_txq->cntxt_id);
+		val = 0xff;
+		rc = -t4_set_params(sc, sc->mbox, sc->pf, 0, 1, &param, &val);
+		if (rc != 0) {
+			device_printf(vi->dev,
+			    "failed to bind netmap txq %d to class 0xff: %d\n",
+			    nm_txq->cntxt_id, rc);
+			rc = 0;
+		}
+	}
+
 	return (rc);
 }