[PATCH net-next 12/13] s390/qeth: add IPv6 RX checksum offload support

Julian Wiedmann
2018-04-26T07:42:23Z

From: Kittipon Meesompop <kmeesomp@linux.vnet.ibm.com>

Check if a qeth device supports IPv6 RX checksum offload, and hook it up
into the existing NETIF_F_RXCSUM support.
As NETIF_F_RXCSUM is now backed by a combination of HW Assists, we need
to be a little smarter when dealing with errors during a configuration
change:
- switching on NETIF_F_RXCSUM only makes sense if at least one HW Assist
was enabled successfully.
- for switching off NETIF_F_RXCSUM, all available HW Assists need to be
deactivated.

Signed-off-by: Kittipon Meesompop <kmeesomp@linux.vnet.ibm.com>
Signed-off-by: Julian Wiedmann <jwi@linux.vnet.ibm.com>
---
drivers/s390/net/qeth_core_main.c | 31 +++++++++++++++++++++++++++----
drivers/s390/net/qeth_core_mpc.h | 1 +
drivers/s390/net/qeth_l2_main.c | 9 +++++----
3 files changed, 33 insertions(+), 8 deletions(-)

diff --git a/drivers/s390/net/qeth_core_main.c b/drivers/s390/net/qeth_core_main.c
index 55b05d9c1cb6..06415b6a8f68 100644
--- a/drivers/s390/net/qeth_core_main.c
+++ b/drivers/s390/net/qeth_core_main.c
@@ -6430,6 +6430,29 @@ static int qeth_set_ipa_tso(struct qeth_card *card, int on)
return rc;
}

+static int qeth_set_ipa_rx_csum(struct qeth_card *card, bool on)
+{
+ int rc_ipv4 = (on) ? -EOPNOTSUPP : 0;
+ int rc_ipv6;
+
+ if (qeth_is_supported(card, IPA_INBOUND_CHECKSUM))
+ rc_ipv4 = qeth_set_ipa_csum(card, on, IPA_INBOUND_CHECKSUM,
+ QETH_PROT_IPV4);
+ if (!qeth_is_supported6(card, IPA_INBOUND_CHECKSUM_V6))
+ /* no/one Offload Assist available, so the rc is trivial */
+ return rc_ipv4;
+
+ rc_ipv6 = qeth_set_ipa_csum(card, on, IPA_INBOUND_CHECKSUM,
+ QETH_PROT_IPV6);
+
+ if (on)
+ /* enable: success if any Assist is active */
+ return (rc_ipv6) ? rc_ipv4 : 0;
+
+ /* disable: failure if any Assist is still active */
+ return (rc_ipv6) ? rc_ipv6 : rc_ipv4;
+}
+
#define QETH_HW_FEATURES (NETIF_F_RXCSUM | NETIF_F_IP_CSUM | NETIF_F_TSO | \
NETIF_F_IPV6_CSUM)
/**
@@ -6477,9 +6500,8 @@ int qeth_set_features(struct net_device *dev, netdev_features_t features)
if (rc)
changed ^= NETIF_F_IPV6_CSUM;
}
- if ((changed & NETIF_F_RXCSUM)) {
- rc = qeth_set_ipa_csum(card, features & NETIF_F_RXCSUM,
- IPA_INBOUND_CHECKSUM, QETH_PROT_IPV4);
+ if (changed & NETIF_F_RXCSUM) {
+ rc = qeth_set_ipa_rx_csum(card, features & NETIF_F_RXCSUM);
if (rc)
changed ^= NETIF_F_RXCSUM;
}
@@ -6508,7 +6530,8 @@ netdev_features_t qeth_fix_features(struct net_device *dev,
features &= ~NETIF_F_IP_CSUM;
if (!qeth_is_supported6(card, IPA_OUTBOUND_CHECKSUM_V6))
features &= ~NETIF_F_IPV6_CSUM;
- if (!qeth_is_supported(card, IPA_INBOUND_CHECKSUM))
+ if (!qeth_is_supported(card, IPA_INBOUND_CHECKSUM) &&
+ !qeth_is_supported6(card, IPA_INBOUND_CHECKSUM_V6))
features &= ~NETIF_F_RXCSUM;
if (!qeth_is_supported(card, IPA_OUTBOUND_TSO))
features &= ~NETIF_F_TSO;
diff --git a/drivers/s390/net/qeth_core_mpc.h b/drivers/s390/net/qeth_core_mpc.h
index af3c35fbfa9e..878e62f35169 100644
--- a/drivers/s390/net/qeth_core_mpc.h
+++ b/drivers/s390/net/qeth_core_mpc.h
@@ -246,6 +246,7 @@ enum qeth_ipa_funcs {
IPA_QUERY_ARP_ASSIST = 0x00040000L,
IPA_INBOUND_TSO = 0x00080000L,
IPA_OUTBOUND_TSO = 0x00100000L,
+ IPA_INBOUND_CHECKSUM_V6 = 0x00400000L,
IPA_OUTBOUND_CHECKSUM_V6 = 0x00800000L,
};

diff --git a/drivers/s390/net/qeth_l2_main.c b/drivers/s390/net/qeth_l2_main.c
index 5b1780fa4cb5..810d69bd9991 100644
--- a/drivers/s390/net/qeth_l2_main.c
+++ b/drivers/s390/net/qeth_l2_main.c
@@ -992,15 +992,16 @@ static int qeth_l2_setup_netdev(struct qeth_card *card)
card->dev->hw_features |= NETIF_F_IP_CSUM;
card->dev->vlan_features |= NETIF_F_IP_CSUM;
}
- if (qeth_is_supported(card, IPA_INBOUND_CHECKSUM)) {
- card->dev->hw_features |= NETIF_F_RXCSUM;
- card->dev->vlan_features |= NETIF_F_RXCSUM;
- }
}
if (qeth_is_supported6(card, IPA_OUTBOUND_CHECKSUM_V6)) {
card->dev->hw_features |= NETIF_F_IPV6_CSUM;
card->dev->vlan_features |= NETIF_F_IPV6_CSUM;
}
+ if (qeth_is_supported(card, IPA_INBOUND_CHECKSUM) ||
+ qeth_is_supported6(card, IPA_INBOUND_CHECKSUM_V6)) {
+ card->dev->hw_features |= NETIF_F_RXCSUM;
+ card->dev->vlan_features |= NETIF_F_RXCSUM;
+ }

card->info.broadcast_capable = 1;
qeth_l2_request_initial_mac(card);
--
2.13.5