From: Julian Wiedmann <jwi@linux.ibm.com>
Subject: s390/qeth: enhance TSO control sequence
Patch-mainline: v4.20-rc1
Git-commit: 4666d7fb1a90280d8d3fa8766b7cdaf822d41a40
References: FATE#326377, LTC#169210, bsc#1115382

Summary:        qeth: Full-blown TCP Segmentation Offload
Description:    As of now, qeth only supports TCP Segmentation Offload (TSO)
                for IPv4 in Layer3 devices. This feature extends the existing
                support to IPv6, and adds support for TSO in both IP variants
                for Layer2.

                To cleanly pull in all the necessary changes to the transmit
                code, update the qeth driver to the current 4.20 level.


Upstream-Description:

             s390/qeth: enhance TSO control sequence

             TSO6 requires the full programming sequence, and not just a simple
             START command. This implements the additional ENABLE command, and adds
             some sanity checks that were missing for the START command.

             Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
             Signed-off-by: David S. Miller <davem@davemloft.net>

Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Acked-by: Petr Tesarik <ptesarik@suse.com>
---
 drivers/s390/net/qeth_core_main.c |   77 +++++++++++++++++++++++++++++++++++++-
 drivers/s390/net/qeth_core_mpc.h  |   26 ++++++++++++
 2 files changed, 101 insertions(+), 2 deletions(-)

--- a/drivers/s390/net/qeth_core_main.c
+++ b/drivers/s390/net/qeth_core_main.c
@@ -5390,6 +5390,21 @@ static int qeth_setassparms_inspect_rc(s
 	return cmd->hdr.return_code;
 }
 
+static int qeth_setassparms_get_caps_cb(struct qeth_card *card,
+					struct qeth_reply *reply,
+					unsigned long data)
+{
+	struct qeth_ipa_cmd *cmd = (struct qeth_ipa_cmd *) data;
+	struct qeth_ipa_caps *caps = reply->param;
+
+	if (qeth_setassparms_inspect_rc(cmd))
+		return 0;
+
+	caps->supported = cmd->data.setassparms.data.caps.supported;
+	caps->enabled = cmd->data.setassparms.data.caps.enabled;
+	return 0;
+}
+
 int qeth_setassparms_cb(struct qeth_card *card,
 			struct qeth_reply *reply, unsigned long data)
 {
@@ -6392,6 +6407,20 @@ static int qeth_set_ipa_csum(struct qeth
 	return rc ? -EIO : 0;
 }
 
+static int qeth_start_tso_cb(struct qeth_card *card, struct qeth_reply *reply,
+			     unsigned long data)
+{
+	struct qeth_ipa_cmd *cmd = (struct qeth_ipa_cmd *) data;
+	struct qeth_tso_start_data *tso_data = reply->param;
+
+	if (qeth_setassparms_inspect_rc(cmd))
+		return 0;
+
+	tso_data->mss = cmd->data.setassparms.data.tso.mss;
+	tso_data->supported = cmd->data.setassparms.data.tso.supported;
+	return 0;
+}
+
 static int qeth_set_tso_off(struct qeth_card *card,
 			    enum qeth_prot_versions prot)
 {
@@ -6402,8 +6431,52 @@ static int qeth_set_tso_off(struct qeth_
 static int qeth_set_tso_on(struct qeth_card *card,
 			   enum qeth_prot_versions prot)
 {
-	return qeth_send_simple_setassparms_prot(card, IPA_OUTBOUND_TSO,
-						 IPA_CMD_ASS_START, 0, prot);
+	struct qeth_tso_start_data tso_data;
+	struct qeth_cmd_buffer *iob;
+	struct qeth_ipa_caps caps;
+	int rc;
+
+	iob = qeth_get_setassparms_cmd(card, IPA_OUTBOUND_TSO,
+				       IPA_CMD_ASS_START, 0, prot);
+	if (!iob)
+		return -ENOMEM;
+
+	rc = qeth_send_setassparms(card, iob, 0, 0 /* unused */,
+				   qeth_start_tso_cb, &tso_data);
+	if (rc)
+		return rc;
+
+	if (!tso_data.mss || !(tso_data.supported & QETH_IPA_LARGE_SEND_TCP)) {
+		qeth_set_tso_off(card, prot);
+		return -EOPNOTSUPP;
+	}
+
+	iob = qeth_get_setassparms_cmd(card, IPA_OUTBOUND_TSO,
+				       IPA_CMD_ASS_ENABLE, sizeof(caps), prot);
+	if (!iob) {
+		qeth_set_tso_off(card, prot);
+		return -ENOMEM;
+	}
+
+	/* enable TSO capability */
+	caps.supported = 0;
+	caps.enabled = QETH_IPA_LARGE_SEND_TCP;
+	rc = qeth_send_setassparms(card, iob, sizeof(caps), (long) &caps,
+				   qeth_setassparms_get_caps_cb, &caps);
+	if (rc) {
+		qeth_set_tso_off(card, prot);
+		return rc;
+	}
+
+	if (!qeth_ipa_caps_supported(&caps, QETH_IPA_LARGE_SEND_TCP) ||
+	    !qeth_ipa_caps_enabled(&caps, QETH_IPA_LARGE_SEND_TCP)) {
+		qeth_set_tso_off(card, prot);
+		return -EOPNOTSUPP;
+	}
+
+	dev_info(&card->gdev->dev, "TSOv%u enabled (MSS: %u)\n", prot,
+		 tso_data.mss);
+	return 0;
 }
 
 static int qeth_set_ipa_tso(struct qeth_card *card, bool on,
--- a/drivers/s390/net/qeth_core_mpc.h
+++ b/drivers/s390/net/qeth_core_mpc.h
@@ -55,6 +55,21 @@ static inline bool qeth_intparm_is_iob(u
 #define IPA_CMD_INITIATOR_OSA_REPLY   0x81
 #define IPA_CMD_PRIM_VERSION_NO 0x01
 
+struct qeth_ipa_caps {
+	u32 supported;
+	u32 enabled;
+};
+
+static inline bool qeth_ipa_caps_supported(struct qeth_ipa_caps *caps, u32 mask)
+{
+	return (caps->supported & mask) == mask;
+}
+
+static inline bool qeth_ipa_caps_enabled(struct qeth_ipa_caps *caps, u32 mask)
+{
+	return (caps->enabled & mask) == mask;
+}
+
 enum qeth_card_types {
 	QETH_CARD_TYPE_OSD     = 1,
 	QETH_CARD_TYPE_IQD     = 5,
@@ -404,14 +419,25 @@ struct qeth_checksum_cmd {
 	__u32 enabled;
 } __packed;
 
+enum qeth_ipa_large_send_caps {
+	QETH_IPA_LARGE_SEND_TCP		= 0x00000001,
+};
+
+struct qeth_tso_start_data {
+	u32 mss;
+	u32 supported;
+};
+
 /* SETASSPARMS IPA Command: */
 struct qeth_ipacmd_setassparms {
 	struct qeth_ipacmd_setassparms_hdr hdr;
 	union {
 		__u32 flags_32bit;
+		struct qeth_ipa_caps caps;
 		struct qeth_checksum_cmd chksum;
 		struct qeth_arp_cache_entry add_arp_entry;
 		struct qeth_arp_query_data query_arp;
+		struct qeth_tso_start_data tso;
 		__u8 ip[16];
 	} data;
 } __attribute__ ((packed));