From: Karsten Graul <kgraul@linux.ibm.com>
Date: Fri, 2 Oct 2020 17:09:26 +0200
Subject: net/smc: send ISM devices with unique chid in CLC proposal
Git-commit: 839d696ffb2714c06da7f55f622d0ac8286524b5
Patch-mainline: v5.10-rc1
References: jsc#SLE-13761

When building a CLC proposal message then the list of ISM devices does
not need to contain multiple devices that have the same chid value,
all these devices use the same function at the end.
Improve smc_find_ism_v2_device_clnt() to collect only ISM devices that
have unique chid values.

Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Petr Tesarik <ptesarik@suse.com>
---
 net/smc/af_smc.c |   18 +++++++++++++++++-
 1 file changed, 17 insertions(+), 1 deletion(-)

--- a/net/smc/af_smc.c
+++ b/net/smc/af_smc.c
@@ -599,6 +599,18 @@ static int smc_find_ism_device(struct sm
 	return 0;
 }
 
+/* is chid unique for the ism devices that are already determined? */
+static bool smc_find_ism_v2_is_unique_chid(u16 chid, struct smc_init_info *ini,
+					   int cnt)
+{
+	int i = (!ini->ism_dev[0]) ? 1 : 0;
+
+	for (; i < cnt; i++)
+		if (ini->ism_chid[i] == chid)
+			return false;
+	return true;
+}
+
 /* determine possible V2 ISM devices (either without PNETID or with PNETID plus
  * PNETID matching net_device)
  */
@@ -608,6 +620,7 @@ static int smc_find_ism_v2_device_clnt(s
 	int rc = SMC_CLC_DECL_NOSMCDDEV;
 	struct smcd_dev *smcd;
 	int i = 1;
+	u16 chid;
 
 	if (smcd_indicated(ini->smc_type_v1))
 		rc = 0;		/* already initialized for V1 */
@@ -615,10 +628,13 @@ static int smc_find_ism_v2_device_clnt(s
 	list_for_each_entry(smcd, &smcd_dev_list.list, list) {
 		if (smcd->going_away || smcd == ini->ism_dev[0])
 			continue;
+		chid = smc_ism_get_chid(smcd);
+		if (!smc_find_ism_v2_is_unique_chid(chid, ini, i))
+			continue;
 		if (!smc_pnet_is_pnetid_set(smcd->pnetid) ||
 		    smc_pnet_is_ndev_pnetid(sock_net(&smc->sk), smcd->pnetid)) {
 			ini->ism_dev[i] = smcd;
-			ini->ism_chid[i] = smc_ism_get_chid(ini->ism_dev[i]);
+			ini->ism_chid[i] = chid;
 			ini->is_smcd = true;
 			rc = 0;
 			i++;