[RFC 10/18] net: macsec: enable HW offloading by default (when available)

[Igor Russkikh <irusskikh@marvell.com>]

From: Mark Starovoytov <mstarovoitov@marvell.com>

This patch makes HW offload to be enabled by default (when available).
This patch along with the next one (reporting real_dev features) are
both required to fix the issue described below.

Issue description:
real_dev features are disabled upon macsec creation.

Root cause:
Features limitation (specific to SW MACSec limitation) is being applied
to HW offloaded case as well.
This causes 'set_features' request on the real_dev with reduced feature
set due to chain propagation.
IF SW MACSec limitations are not applied to HW offloading case (see the
next path), then we still face an issue, because SW MACSec is enabled by
default.

Proposed solution:
Enable HW offloading by default (when available).

Signed-off-by: Mark Starovoytov <mstarovoitov@marvell.com>
Signed-off-by: Igor Russkikh <irusskikh@marvell.com>
---
 drivers/net/macsec.c | 23 +++++++++++++++++++++--
 1 file changed, 21 insertions(+), 2 deletions(-)

diff --git a/drivers/net/macsec.c b/drivers/net/macsec.c
index 0ee647238996..38403037cea0 100644
--- a/drivers/net/macsec.c
+++ b/drivers/net/macsec.c
@@ -3816,8 +3816,13 @@ static int macsec_newlink(struct net *net, struct net_device *dev,
 
 	macsec->real_dev = real_dev;
 
-	/* MACsec offloading is off by default */
-	macsec->offload = MACSEC_OFFLOAD_OFF;
+	/* If h/w offloading is available, enable it by default */
+	if (real_dev->features & NETIF_F_HW_MACSEC && real_dev->macsec_ops)
+		macsec->offload = MACSEC_OFFLOAD_MAC;
+	else if (real_dev->phydev && real_dev->phydev->macsec_ops)
+		macsec->offload = MACSEC_OFFLOAD_PHY;
+	else
+		macsec->offload = MACSEC_OFFLOAD_OFF;
 
 	if (data && data[IFLA_MACSEC_ICV_LEN])
 		icv_len = nla_get_u8(data[IFLA_MACSEC_ICV_LEN]);
@@ -3860,6 +3865,20 @@ static int macsec_newlink(struct net *net, struct net_device *dev,
 			goto del_dev;
 	}
 
+	/* If h/w offloading is available, propagate to the device */
+	if (macsec_is_offloaded(macsec)) {
+		const struct macsec_ops *ops;
+		struct macsec_context ctx;
+
+		ops = macsec_get_ops(macsec, &ctx);
+		if (ops) {
+			ctx.secy = &macsec->secy;
+			err = macsec_offload(ops->mdo_add_secy, &ctx);
+			if (err)
+				goto del_dev;
+		}
+	}
+
 	err = register_macsec_dev(real_dev, dev);
 	if (err < 0)
 		goto del_dev;
-- 
2.17.1