cxgb4: Query firmware for T5 ULPTX MEMWRITE DSGL capabilities

Query firmware to see whether we're allowed to use T5 ULPTX MEMWRITE DSGL
capabilities.  Also pass that information to Upper Layer Drivers via the
new (struct cxgb4_lld_info).ulptx_memwrite_dsgl boolean.

Based on original work by Casey Leedom <leedom@chelsio.com>

Signed-off-by: Kumar Sanghvi <kumaras@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c b/drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c
index 9222a8a..aeeaa06 100644
--- a/drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c
+++ b/drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c
@@ -3776,6 +3776,7 @@
 	lli.dbfifo_int_thresh = dbfifo_int_thresh;
 	lli.sge_pktshift = adap->sge.pktshift;
 	lli.enable_fw_ofld_conn = adap->flags & FW_OFLD_CONN;
+	lli.ulptx_memwrite_dsgl = adap->params.ulptx_memwrite_dsgl;
 
 	handle = ulds[uld].add(&lli);
 	if (IS_ERR(handle)) {
@@ -5381,6 +5382,21 @@
 	(void) t4_set_params(adap, adap->mbox, adap->fn, 0, 1, params, val);
 
 	/*
+	 * Find out whether we're allowed to use the T5+ ULPTX MEMWRITE DSGL
+	 * capability.  Earlier versions of the firmware didn't have the
+	 * ULPTX_MEMWRITE_DSGL so we'll interpret a query failure as no
+	 * permission to use ULPTX MEMWRITE DSGL.
+	 */
+	if (is_t4(adap->params.chip)) {
+		adap->params.ulptx_memwrite_dsgl = false;
+	} else {
+		params[0] = FW_PARAM_DEV(ULPTX_MEMWRITE_DSGL);
+		ret = t4_query_params(adap, adap->mbox, adap->fn, 0,
+				      1, params, val);
+		adap->params.ulptx_memwrite_dsgl = (ret == 0 && val[0] != 0);
+	}
+
+	/*
 	 * Get device capabilities so we can determine what resources we need
 	 * to manage.
 	 */