[PATCH net-next 11/13] s390/qeth: add IPv6 TX checksum offload support

Julian Wiedmann
2018-04-26T07:42:22Z

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

Check if a qeth device supports IPv6 TX checksum offload, and advertise
NETIF_F_IPV6_CSUM accordingly. Add support for setting the relevant bits
in IPv6 packet descriptors.

Currently this has only limited use (ie. UDP, or Jumbo Frames). For any
TCP traffic with a standard MSS, the TCP checksum gets calculated
as part of the linear GSO segmentation.

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.h | 13 ++++++++-----
drivers/s390/net/qeth_core_main.c | 18 +++++++++++++-----
drivers/s390/net/qeth_core_mpc.h | 1 +
drivers/s390/net/qeth_l2_main.c | 14 ++++++++++----
drivers/s390/net/qeth_l3_main.c | 7 ++++++-
5 files changed, 38 insertions(+), 15 deletions(-)

diff --git a/drivers/s390/net/qeth_core.h b/drivers/s390/net/qeth_core.h
index 7cbc9bf5d6b0..2a5fec55bf60 100644
--- a/drivers/s390/net/qeth_core.h
+++ b/drivers/s390/net/qeth_core.h
@@ -878,14 +878,17 @@ static inline void qeth_rx_csum(struct qeth_card *card, struct sk_buff *skb,
}
}

-static inline void qeth_tx_csum(struct sk_buff *skb, u8 *flags)
+static inline void qeth_tx_csum(struct sk_buff *skb, u8 *flags, int ipv)
{
*flags |= QETH_HDR_EXT_CSUM_TRANSP_REQ;
- if (ip_hdr(skb)->protocol == IPPROTO_UDP)
+ if ((ipv == 4 && ip_hdr(skb)->protocol == IPPROTO_UDP) ||
+ (ipv == 6 && ipv6_hdr(skb)->nexthdr == IPPROTO_UDP))
*flags |= QETH_HDR_EXT_UDP;
- /* some HW requires combined L3+L4 csum offload: */
- *flags |= QETH_HDR_EXT_CSUM_HDR_REQ;
- ip_hdr(skb)->check = 0;
+ if (ipv == 4) {
+ /* some HW requires combined L3+L4 csum offload: */
+ *flags |= QETH_HDR_EXT_CSUM_HDR_REQ;
+ ip_hdr(skb)->check = 0;
+ }
}

static inline void qeth_put_buffer_pool_entry(struct qeth_card *card,
diff --git a/drivers/s390/net/qeth_core_main.c b/drivers/s390/net/qeth_core_main.c
index 5e4a509822f1..55b05d9c1cb6 100644
--- a/drivers/s390/net/qeth_core_main.c
+++ b/drivers/s390/net/qeth_core_main.c
@@ -6349,12 +6349,12 @@ static int qeth_ipa_checksum_run_cmd(struct qeth_card *card,
static int qeth_send_checksum_on(struct qeth_card *card, int cstype,
enum qeth_prot_versions prot)
{
- const __u32 required_features = QETH_IPA_CHECKSUM_IP_HDR |
- QETH_IPA_CHECKSUM_UDP |
- QETH_IPA_CHECKSUM_TCP;
+ u32 required_features = QETH_IPA_CHECKSUM_UDP | QETH_IPA_CHECKSUM_TCP;
struct qeth_checksum_cmd chksum_cb;
int rc;

+ if (prot == QETH_PROT_IPV4)
+ required_features |= QETH_IPA_CHECKSUM_IP_HDR;
rc = qeth_ipa_checksum_run_cmd(card, cstype, IPA_CMD_ASS_START, 0,
&chksum_cb, prot);
if (!rc) {
@@ -6430,8 +6430,8 @@ static int qeth_set_ipa_tso(struct qeth_card *card, int on)
return rc;
}

-#define QETH_HW_FEATURES (NETIF_F_RXCSUM | NETIF_F_IP_CSUM | NETIF_F_TSO)
-
+#define QETH_HW_FEATURES (NETIF_F_RXCSUM | NETIF_F_IP_CSUM | NETIF_F_TSO | \
+ NETIF_F_IPV6_CSUM)
/**
* qeth_recover_features() - Restore device features after recovery
* @dev: the recovering net_device
@@ -6471,6 +6471,12 @@ int qeth_set_features(struct net_device *dev, netdev_features_t features)
if (rc)
changed ^= NETIF_F_IP_CSUM;
}
+ if (changed & NETIF_F_IPV6_CSUM) {
+ rc = qeth_set_ipa_csum(card, features & NETIF_F_IPV6_CSUM,
+ IPA_OUTBOUND_CHECKSUM, QETH_PROT_IPV6);
+ 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);
@@ -6500,6 +6506,8 @@ netdev_features_t qeth_fix_features(struct net_device *dev,
QETH_DBF_TEXT(SETUP, 2, "fixfeat");
if (!qeth_is_supported(card, IPA_OUTBOUND_CHECKSUM))
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))
features &= ~NETIF_F_RXCSUM;
if (!qeth_is_supported(card, IPA_OUTBOUND_TSO))
diff --git a/drivers/s390/net/qeth_core_mpc.h b/drivers/s390/net/qeth_core_mpc.h
index f4d1ec0b8f5a..af3c35fbfa9e 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_OUTBOUND_CHECKSUM_V6 = 0x00800000L,
};

/* SETIP/DELIP IPA Command: ***************************************************/
diff --git a/drivers/s390/net/qeth_l2_main.c b/drivers/s390/net/qeth_l2_main.c
index 945df56434fd..5b1780fa4cb5 100644
--- a/drivers/s390/net/qeth_l2_main.c
+++ b/drivers/s390/net/qeth_l2_main.c
@@ -660,7 +660,8 @@ static int qeth_l2_xmit_iqd(struct qeth_card *card, struct sk_buff *skb,
}

static int qeth_l2_xmit_osa(struct qeth_card *card, struct sk_buff *skb,
- struct qeth_qdio_out_q *queue, int cast_type)
+ struct qeth_qdio_out_q *queue, int cast_type,
+ int ipv)
{
int push_len = sizeof(struct qeth_hdr);
unsigned int elements, nr_frags;
@@ -699,7 +700,7 @@ static int qeth_l2_xmit_osa(struct qeth_card *card, struct sk_buff *skb,
}
qeth_l2_fill_header(hdr, skb, cast_type, skb->len - push_len);
if (skb->ip_summed == CHECKSUM_PARTIAL) {
- qeth_tx_csum(skb, &hdr->hdr.l2.flags[1]);
+ qeth_tx_csum(skb, &hdr->hdr.l2.flags[1], ipv);
if (card->options.performance_stats)
card->perf_stats.tx_csum++;
}
@@ -754,6 +755,7 @@ static netdev_tx_t qeth_l2_hard_start_xmit(struct sk_buff *skb,
{
struct qeth_card *card = dev->ml_priv;
int cast_type = qeth_l2_get_cast_type(card, skb);
+ int ipv = qeth_get_ip_version(skb);
struct qeth_qdio_out_q *queue;
int tx_bytes = skb->len;
int rc;
@@ -761,7 +763,7 @@ static netdev_tx_t qeth_l2_hard_start_xmit(struct sk_buff *skb,
if (card->qdio.do_prio_queueing || (cast_type &&
card->info.is_multicast_different))
queue = card->qdio.out_qs[qeth_get_priority_queue(card, skb,
- qeth_get_ip_version(skb), cast_type)];
+ ipv, cast_type)];
else
queue = card->qdio.out_qs[card->qdio.default_out_queue];

@@ -784,7 +786,7 @@ static netdev_tx_t qeth_l2_hard_start_xmit(struct sk_buff *skb,
rc = qeth_l2_xmit_iqd(card, skb, queue, cast_type);
break;
default:
- rc = qeth_l2_xmit_osa(card, skb, queue, cast_type);
+ rc = qeth_l2_xmit_osa(card, skb, queue, cast_type, ipv);
}

if (!rc) {
@@ -995,6 +997,10 @@ static int qeth_l2_setup_netdev(struct qeth_card *card)
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;
+ }

card->info.broadcast_capable = 1;
qeth_l2_request_initial_mac(card);
diff --git a/drivers/s390/net/qeth_l3_main.c b/drivers/s390/net/qeth_l3_main.c
index dd233fe3d6c4..e7fa479adf47 100644
--- a/drivers/s390/net/qeth_l3_main.c
+++ b/drivers/s390/net/qeth_l3_main.c
@@ -2281,7 +2281,7 @@ static netdev_tx_t qeth_l3_hard_start_xmit(struct sk_buff *skb,
}

if (new_skb->ip_summed == CHECKSUM_PARTIAL) {
- qeth_tx_csum(new_skb, &hdr->hdr.l3.ext_flags);
+ qeth_tx_csum(new_skb, &hdr->hdr.l3.ext_flags, ipv);
if (card->options.performance_stats)
card->perf_stats.tx_csum++;
}
@@ -2507,6 +2507,11 @@ static int qeth_l3_setup_netdev(struct qeth_card *card)
card->dev->vlan_features |= NETIF_F_TSO |
NETIF_F_RXCSUM | NETIF_F_IP_CSUM;
}
+
+ 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;
+ }
} else if (card->info.type == QETH_CARD_TYPE_IQD) {
card->dev = alloc_netdev(0, "hsi%d", NET_NAME_UNKNOWN,
ether_setup);
--
2.13.5