RDMA/cxgb4: Add support for MPAv2 Enhanced RDMA Negotiation

This patch adds support for Enhanced RDMA Connection Establishment
(draft-ietf-storm-mpa-peer-connect-06), aka MPAv2.  Details of draft
can be obtained from:
<http://www.ietf.org/id/draft-ietf-storm-mpa-peer-connect-06.txt>

The patch updates the following functions for initiator perspective:
 - send_mpa_request
 - process_mpa_reply
 - post_terminate for TERM error codes
 - destroy_qp for TERM related change
 - adds layer/etype/ecode to c4iw_qp_attrs for sending with TERM
 - peer_abort for retrying connection attempt with MPA_v1 message
 - added c4iw_reconnect function

The patch updates the following functions for responder perspective:
 - process_mpa_request
 - send_mpa_reply
 - c4iw_accept_cr
 - passes ird/ord to upper layers

Signed-off-by: Kumar Sanghvi <kumaras@chelsio.com>
Reviewed-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>

3 files changed, 466 insertions, 39 deletions

diff --git a/drivers/infiniband/hw/cxgb4/cm.c b/drivers/infiniband/hw/cxgb4/cm.c
index 77f769d9227d..b36cdac9c558 100644
--- a/drivers/infiniband/hw/cxgb4/cm.c
+++ b/drivers/infiniband/hw/cxgb4/cm.c
@@ -103,7 +103,8 @@ MODULE_PARM_DESC(ep_timeout_secs, "CM Endpoint operation timeout "
 static int mpa_rev = 1;
 module_param(mpa_rev, int, 0644);
 MODULE_PARM_DESC(mpa_rev, "MPA Revision, 0 supports amso1100, "
-                 "1 is spec compliant. (default=1)");
+                "1 is RFC0544 spec compliant, 2 is IETF MPA Peer Connect Draft"
+                " compliant (default=1)");
 
 static int markers_enabled;
 module_param(markers_enabled, int, 0644);
@@ -497,17 +498,21 @@ static int send_connect(struct c4iw_ep *ep)
         return c4iw_l2t_send(&ep->com.dev->rdev, skb, ep->l2t);
 }
 
-static void send_mpa_req(struct c4iw_ep *ep, struct sk_buff *skb)
+static void send_mpa_req(struct c4iw_ep *ep, struct sk_buff *skb,
+                u8 mpa_rev_to_use)
 {
         int mpalen, wrlen;
         struct fw_ofld_tx_data_wr *req;
         struct mpa_message *mpa;
+        struct mpa_v2_conn_params mpa_v2_params;
 
         PDBG("%s ep %p tid %u pd_len %d\n", __func__, ep, ep->hwtid, ep->plen);
 
         BUG_ON(skb_cloned(skb));
 
         mpalen = sizeof(*mpa) + ep->plen;
+        if (mpa_rev_to_use == 2)
+                mpalen += sizeof(struct mpa_v2_conn_params);
         wrlen = roundup(mpalen + sizeof *req, 16);
         skb = get_skb(skb, wrlen, GFP_KERNEL);
         if (!skb) {
@@ -533,12 +538,39 @@ static void send_mpa_req(struct c4iw_ep *ep, struct sk_buff *skb)
         mpa = (struct mpa_message *)(req + 1);
         memcpy(mpa->key, MPA_KEY_REQ, sizeof(mpa->key));
         mpa->flags = (crc_enabled ? MPA_CRC : 0) |
-                     (markers_enabled ? MPA_MARKERS : 0);
+                     (markers_enabled ? MPA_MARKERS : 0) |
+                     (mpa_rev_to_use == 2 ? MPA_ENHANCED_RDMA_CONN : 0);
         mpa->private_data_size = htons(ep->plen);
-        mpa->revision = mpa_rev;
+        mpa->revision = mpa_rev_to_use;
+        if (mpa_rev_to_use == 1)
+                ep->tried_with_mpa_v1 = 1;
+
+        if (mpa_rev_to_use == 2) {
+                mpa->private_data_size +=
+                        htons(sizeof(struct mpa_v2_conn_params));
+                mpa_v2_params.ird = htons((u16)ep->ird);
+                mpa_v2_params.ord = htons((u16)ep->ord);
+
+                if (peer2peer) {
+                        mpa_v2_params.ird |= htons(MPA_V2_PEER2PEER_MODEL);
+                        if (p2p_type == FW_RI_INIT_P2PTYPE_RDMA_WRITE)
+                                mpa_v2_params.ord |=
+                                        htons(MPA_V2_RDMA_WRITE_RTR);
+                        else if (p2p_type == FW_RI_INIT_P2PTYPE_READ_REQ)
+                                mpa_v2_params.ord |=
+                                        htons(MPA_V2_RDMA_READ_RTR);
+                }
+                memcpy(mpa->private_data, &mpa_v2_params,
+                       sizeof(struct mpa_v2_conn_params));
 
-        if (ep->plen)
-                memcpy(mpa->private_data, ep->mpa_pkt + sizeof(*mpa), ep->plen);
+                if (ep->plen)
+                        memcpy(mpa->private_data +
+                               sizeof(struct mpa_v2_conn_params),
+                               ep->mpa_pkt + sizeof(*mpa), ep->plen);
+        } else
+                if (ep->plen)
+                        memcpy(mpa->private_data,
+                                        ep->mpa_pkt + sizeof(*mpa), ep->plen);
 
         /*
          * Reference the mpa skb.  This ensures the data area
@@ -562,10 +594,13 @@ static int send_mpa_reject(struct c4iw_ep *ep, const void *pdata, u8 plen)
         struct fw_ofld_tx_data_wr *req;
         struct mpa_message *mpa;
         struct sk_buff *skb;
+        struct mpa_v2_conn_params mpa_v2_params;
 
         PDBG("%s ep %p tid %u pd_len %d\n", __func__, ep, ep->hwtid, ep->plen);
 
         mpalen = sizeof(*mpa) + plen;
+        if (ep->mpa_attr.version == 2 && ep->mpa_attr.enhanced_rdma_conn)
+                mpalen += sizeof(struct mpa_v2_conn_params);
         wrlen = roundup(mpalen + sizeof *req, 16);
 
         skb = get_skb(NULL, wrlen, GFP_KERNEL);
@@ -595,8 +630,29 @@ static int send_mpa_reject(struct c4iw_ep *ep, const void *pdata, u8 plen)
         mpa->flags = MPA_REJECT;
         mpa->revision = mpa_rev;
         mpa->private_data_size = htons(plen);
-        if (plen)
-                memcpy(mpa->private_data, pdata, plen);
+
+        if (ep->mpa_attr.version == 2 && ep->mpa_attr.enhanced_rdma_conn) {
+                mpa->flags |= MPA_ENHANCED_RDMA_CONN;
+                mpa->private_data_size +=
+                        htons(sizeof(struct mpa_v2_conn_params));
+                mpa_v2_params.ird = htons(((u16)ep->ird) |
+                                          (peer2peer ? MPA_V2_PEER2PEER_MODEL :
+                                           0));
+                mpa_v2_params.ord = htons(((u16)ep->ord) | (peer2peer ?
+                                          (p2p_type ==
+                                           FW_RI_INIT_P2PTYPE_RDMA_WRITE ?
+                                           MPA_V2_RDMA_WRITE_RTR : p2p_type ==
+                                           FW_RI_INIT_P2PTYPE_READ_REQ ?
+                                           MPA_V2_RDMA_READ_RTR : 0) : 0));
+                memcpy(mpa->private_data, &mpa_v2_params,
+                       sizeof(struct mpa_v2_conn_params));
+
+                if (ep->plen)
+                        memcpy(mpa->private_data +
+                               sizeof(struct mpa_v2_conn_params), pdata, plen);
+        } else
+                if (plen)
+                        memcpy(mpa->private_data, pdata, plen);
 
         /*
          * Reference the mpa skb again.  This ensures the data area
@@ -617,10 +673,13 @@ static int send_mpa_reply(struct c4iw_ep *ep, const void *pdata, u8 plen)
         struct fw_ofld_tx_data_wr *req;
         struct mpa_message *mpa;
         struct sk_buff *skb;
+        struct mpa_v2_conn_params mpa_v2_params;
 
         PDBG("%s ep %p tid %u pd_len %d\n", __func__, ep, ep->hwtid, ep->plen);
 
         mpalen = sizeof(*mpa) + plen;
+        if (ep->mpa_attr.version == 2 && ep->mpa_attr.enhanced_rdma_conn)
+                mpalen += sizeof(struct mpa_v2_conn_params);
         wrlen = roundup(mpalen + sizeof *req, 16);
 
         skb = get_skb(NULL, wrlen, GFP_KERNEL);
@@ -649,10 +708,36 @@ static int send_mpa_reply(struct c4iw_ep *ep, const void *pdata, u8 plen)
         memcpy(mpa->key, MPA_KEY_REP, sizeof(mpa->key));
         mpa->flags = (ep->mpa_attr.crc_enabled ? MPA_CRC : 0) |
                      (markers_enabled ? MPA_MARKERS : 0);
-        mpa->revision = mpa_rev;
+        mpa->revision = ep->mpa_attr.version;
         mpa->private_data_size = htons(plen);
-        if (plen)
-                memcpy(mpa->private_data, pdata, plen);
+
+        if (ep->mpa_attr.version == 2 && ep->mpa_attr.enhanced_rdma_conn) {
+                mpa->flags |= MPA_ENHANCED_RDMA_CONN;
+                mpa->private_data_size +=
+                        htons(sizeof(struct mpa_v2_conn_params));