NTB: perf: Fix support for hardware that doesn't have port numbers

[ Upstream commit b54369a248c2e033bfcf5d6917e08cf9d73d54a6 ] Legacy drivers do not have port numbers (but is reliably only two ports) and was broken by the recent commit that added mult-port support to ntb_perf. This is especially important to support the cross link topology which is perfectly symmetric and cannot assign unique port numbers easily. Hardware that returns zero for both the local port and the peer should just always use gidx=0 for the only peer. Fixes: 5648e56 ("NTB: ntb_perf: Add full multi-port NTB API support") Signed-off-by: Logan Gunthorpe <[email protected]> Acked-by: Allen Hubbe <[email protected]> Tested-by: Alexander Fomichev <[email protected]> Signed-off-by: Jon Mason <[email protected]> Signed-off-by: Sasha Levin <[email protected]>
akeromi · Jun 25, 2020 · f16225d · f16225d
1 parent b3f110e
commit f16225d
Showing 1 changed file with 10 additions and 0 deletions.
diff --git a/drivers/ntb/test/ntb_perf.c b/drivers/ntb/test/ntb_perf.c
@@ -1418,6 +1418,16 @@ static int perf_init_peers(struct perf_ctx *perf)
 	if (perf->gidx == -1)
 		perf->gidx = pidx;
 
+	/*
+	 * Hardware with only two ports may not have unique port
+	 * numbers. In this case, the gidxs should all be zero.
+	 */
+	if (perf->pcnt == 1 &&  ntb_port_number(perf->ntb) == 0 &&
+	    ntb_peer_port_number(perf->ntb, 0) == 0) {
+		perf->gidx = 0;
+		perf->peers[0].gidx = 0;
+	}
+
 	for (pidx = 0; pidx < perf->pcnt; pidx++) {
 		ret = perf_setup_peer_mw(&perf->peers[pidx]);
 		if (ret)