IB: Return qp pointer as part of ib_wc

struct ib_wc currently only includes the local QP number: this matches
the IB spec, but seems mostly useless. The following patch replaces
this with the pointer to qp itself, and updates all low level drivers
and all users.

This has the following advantages:
- Ability to get a per-qp context through wc->qp->qp_context
- Existing drivers already have the qp pointer ready in poll cq, so
  this change actually saves a tiny bit (extra memory read) on data path
  (for ehca it would actually be expensive to find the QP pointer when
  polling a CQ, but ehca does not support SRQ so we can leave wc->qp as
  NULL for ehca)
- Users that need the QP number can still get it through wc->qp->qp_num

Use case:

In IPoIB connected mode code, I have a common CQ shared by multiple
QPs.  To track connection usage, I need a way to get at some per-QP
context upon the completion, and I would like to avoid allocating
context object per work request just to stick a QP pointer into it.
With this code, I can just use wc->qp->qp_context.

Signed-off-by: Michael S. Tsirkin <mst@mellanox.co.il>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

12 files changed, 28 insertions, 25 deletions

diff --git a/drivers/infiniband/core/mad.c b/drivers/infiniband/core/mad.c
index 5ed141ebd1c..13efd417034 100644
--- a/drivers/infiniband/core/mad.c
+++ b/drivers/infiniband/core/mad.c
@@ -642,7 +642,8 @@ static void snoop_recv(struct ib_mad_qp_info *qp_info,
 	spin_unlock_irqrestore(&qp_info->snoop_lock, flags);
 }
 
-static void build_smp_wc(u64 wr_id, u16 slid, u16 pkey_index, u8 port_num,
+static void build_smp_wc(struct ib_qp *qp,
+			 u64 wr_id, u16 slid, u16 pkey_index, u8 port_num,
 			 struct ib_wc *wc)
 {
 	memset(wc, 0, sizeof *wc);
@@ -652,7 +653,7 @@ static void build_smp_wc(u64 wr_id, u16 slid, u16 pkey_index, u8 port_num,
 	wc->pkey_index = pkey_index;
 	wc->byte_len = sizeof(struct ib_mad) + sizeof(struct ib_grh);
 	wc->src_qp = IB_QP0;
-	wc->qp_num = IB_QP0;
+	wc->qp = qp;
 	wc->slid = slid;
 	wc->sl = 0;
 	wc->dlid_path_bits = 0;
@@ -713,7 +714,8 @@ static int handle_outgoing_dr_smp(struct ib_mad_agent_private *mad_agent_priv,
 		goto out;
 	}
 
-	build_smp_wc(send_wr->wr_id, be16_to_cpu(smp->dr_slid),
+	build_smp_wc(mad_agent_priv->agent.qp,
+		     send_wr->wr_id, be16_to_cpu(smp->dr_slid),
 		     send_wr->wr.ud.pkey_index,
 		     send_wr->wr.ud.port_num, &mad_wc);
 
@@ -2355,7 +2357,8 @@ static void local_completions(struct work_struct *work)
 			 * Defined behavior is to complete response
 			 * before request
 			 */
-			build_smp_wc((unsigned long) local->mad_send_wr,
+			build_smp_wc(recv_mad_agent->agent.qp,
+				     (unsigned long) local->mad_send_wr,
 				     be16_to_cpu(IB_LID_PERMISSIVE),
 				     0, recv_mad_agent->agent.port_num, &wc);
 
diff --git a/drivers/infiniband/core/uverbs_cmd.c b/drivers/infiniband/core/uverbs_cmd.c
index 743247ec065..df1efbc1088 100644
--- a/drivers/infiniband/core/uverbs_cmd.c
+++ b/drivers/infiniband/core/uverbs_cmd.c
@@ -933,7 +933,7 @@ ssize_t ib_uverbs_poll_cq(struct ib_uverbs_file *file,
 		resp->wc[i].vendor_err 	   = wc[i].vendor_err;
 		resp->wc[i].byte_len 	   = wc[i].byte_len;
 		resp->wc[i].imm_data 	   = (__u32 __force) wc[i].imm_data;
-		resp->wc[i].qp_num 	   = wc[i].qp_num;
+		resp->wc[i].qp_num 	   = wc[i].qp->qp_num;
 		resp->wc[i].src_qp 	   = wc[i].src_qp;
 		resp->wc[i].wc_flags 	   = wc[i].wc_flags;
 		resp->wc[i].pkey_index 	   = wc[i].pkey_index;
diff --git a/drivers/infiniband/hw/amso1100/c2_cq.c b/drivers/infiniband/hw/amso1100/c2_cq.c
index 05c9154d46f..5175c99ee58 100644
--- a/drivers/infiniband/hw/amso1100/c2_cq.c
+++ b/drivers/infiniband/hw/amso1100/c2_cq.c
@@ -153,7 +153,7 @@ static inline int c2_poll_one(struct c2_dev *c2dev,
 
 	entry->status = c2_cqe_status_to_openib(c2_wr_get_result(ce));
 	entry->wr_id = ce->hdr.context;
-	entry->qp_num = ce->handle;
+	entry->qp = &qp->ibqp;
 	entry->wc_flags = 0;
 	entry->slid = 0;
 	entry->sl = 0;
diff --git a/drivers/infiniband/hw/ehca/ehca_reqs.c b/drivers/infiniband/hw/ehca/ehca_reqs.c
index b46bda1bf85..08d3f892d9f 100644
--- a/drivers/infiniband/hw/ehca/ehca_reqs.c
+++ b/drivers/infiniband/hw/ehca/ehca_reqs.c
@@ -579,7 +579,7 @@ poll_cq_one_read_cqe:
 	} else
 		wc->status = IB_WC_SUCCESS;
 
-	wc->qp_num = cqe->local_qp_number;
+	wc->qp = NULL;
 	wc->byte_len = cqe->nr_bytes_transferred;
 	wc->pkey_index = cqe->pkey_index;
 	wc->slid = cqe->rlid;
diff --git a/drivers/infiniband/hw/ipath/ipath_qp.c b/drivers/infiniband/hw/ipath/ipath_qp.c
index 46c1c89bf6a..64f07b19349 100644
--- a/drivers/infiniband/hw/ipath/ipath_qp.c
+++ b/drivers/infiniband/hw/ipath/ipath_qp.c
@@ -379,7 +379,7 @@ void ipath_error_qp(struct ipath_qp *qp, enum ib_wc_status err)
 	wc.vendor_err = 0;
 	wc.byte_len = 0;
 	wc.imm_data = 0;
-	wc.qp_num = qp->ibqp.qp_num;
+	wc.qp = &qp->ibqp;
 	wc.src_qp = 0;
 	wc.wc_flags = 0;
 	wc.pkey_index = 0;
diff --git a/drivers/infiniband/hw/ipath/ipath_rc.c b/drivers/infiniband/hw/ipath/ipath_rc.c
index ce6038743c5..5ff20cb0449 100644
--- a/drivers/infiniband/hw/ipath/ipath_rc.c
+++ b/drivers/infiniband/hw/ipath/ipath_rc.c
@@ -702,7 +702,7 @@ void ipath_restart_rc(struct ipath_qp *qp, u32 psn, struct ib_wc *wc)
 		wc->opcode = ib_ipath_wc_opcode[wqe->wr.opcode];
 		wc->vendor_err = 0;
 		wc->byte_len = 0;
-		wc->qp_num = qp->ibqp.qp_num;
+		wc->qp = &qp->ibqp;
 		wc->src_qp = qp->remote_qpn;
 		wc->pkey_index = 0;
 		wc->slid = qp->remote_ah_attr.dlid;
@@ -836,7 +836,7 @@ static int do_rc_ack(struct ipath_qp *qp, u32 aeth, u32 psn, int opcode)
 			wc.opcode = ib_ipath_wc_opcode[wqe->wr.opcode];
 			wc.vendor_err = 0;
 			wc.byte_len = wqe->length;
-			wc.qp_num = qp->ibqp.qp_num;
+			wc.qp = &qp->ibqp;
 			wc.src_qp = qp->remote_qpn;
 			wc.pkey_index = 0;
 			wc.slid = qp->remote_ah_attr.dlid;
@@ -951,7 +951,7 @@ static int do_rc_ack(struct ipath_qp *qp, u32 aeth, u32 psn, int opcode)
 			wc.opcode = ib_ipath_wc_opcode[wqe->wr.opcode];
 			wc.vendor_err = 0;
 			wc.byte_len = 0;
-			wc.qp_num = qp->ibqp.qp_num;
+			wc.qp = &qp->ibqp;
 			wc.src_qp = qp->remote_qpn;
 			wc.pkey_index = 0;
 			wc.slid = qp->remote_ah_attr.dlid;
@@ -1511,7 +1511,7 @@ void ipath_rc_rcv(struct ipath_ibdev *dev, struct ipath_ib_header *hdr,
 		wc.status = IB_WC_SUCCESS;
 		wc.opcode = IB_WC_RECV;
 		wc.vendor_err = 0;
-		wc.qp_num = qp->ibqp.qp_num;
+		wc.qp = &qp->ibqp;
 		wc.src_qp = qp->remote_qpn;
 		wc.pkey_index = 0;
 		wc.slid = qp->remote_ah_attr.dlid;
diff --git a/drivers/infiniband/hw/ipath/ipath_ruc.c b/drivers/infiniband/hw/ipath/ipath_ruc.c
index f7530512045..e86cb171872 100644
--- a/drivers/infiniband/hw/ipath/ipath_ruc.c
+++ b/drivers/infiniband/hw/ipath/ipath_ruc.c
@@ -137,7 +137,7 @@ bad_lkey:
 	wc.vendor_err = 0;
 	wc.byte_len = 0;
 	wc.imm_data = 0;
-	wc.qp_num = qp->ibqp.qp_num;
+	wc.qp = &qp->ibqp;
 	wc.src_qp = 0;
 	wc.wc_flags = 0;
 	wc.pkey_index = 0;
@@ -336,7 +336,7 @@ again:
 			wc.opcode = ib_ipath_wc_opcode[wqe->wr.opcode];
 			wc.vendor_err = 0;
 			wc.byte_len = 0;
-			wc.qp_num = sqp->ibqp.qp_num;
+			wc.qp = &sqp->ibqp;
 			wc.src_qp = sqp->remote_qpn;
 			wc.pkey_index = 0;
 			wc.slid = sqp->remote_ah_attr.dlid;
@@ -426,7 +426,7 @@ again:
 	wc.status = IB_WC_SUCCESS;
 	wc.vendor_err = 0;
 	wc.byte_len = wqe->length;
-	wc.qp_num = qp->ibqp.qp_num;
+	wc.qp = &qp->ibqp;
 	wc.src_qp = qp->remote_qpn;
 	/* XXX do we know which pkey matched? Only needed for GSI. */
 	wc.pkey_index = 0;
@@ -447,7 +447,7 @@ send_comp:
 		wc.opcode = ib_ipath_wc_opcode[wqe->wr.opcode];
 		wc.vendor_err = 0;
 		wc.byte_len = wqe->length;
-		wc.qp_num = sqp->ibqp.qp_num;
+		wc.qp = &sqp->ibqp;
 		wc.src_qp = 0;
 		wc.pkey_index = 0;
 		wc.slid = 0;
diff --git a/drivers/infiniband/hw/ipath/ipath_uc.c b/drivers/infiniband/hw/ipath/ipath_uc.c
index e636cfd67a8..325d6634ff5 100644
--- a/drivers/infiniband/hw/ipath/ipath_uc.c
+++ b/drivers/infiniband/hw/ipath/ipath_uc.c
@@ -49,7 +49,7 @@ static void complete_last_send(struct ipath_qp *qp, struct ipath_swqe *wqe,
 		wc->opcode = ib_ipath_wc_opcode[wqe->wr.opcode];
 		wc->vendor_err = 0;
 		wc->byte_len = wqe->length;
-		wc->qp_num = qp->ibqp.qp_num;
+		wc->qp = &qp->ibqp;
 		wc->src_qp = qp->remote_qpn;
 		wc->pkey_index = 0;
 		wc->slid = qp->remote_ah_attr.dlid;
@@ -411,7 +411,7 @@ void ipath_uc_rcv(struct ipath_ibdev *dev, struct ipath_ib_header *hdr,
 		wc.status = IB_WC_SUCCESS;
 		wc.opcode = IB_WC_RECV;
 		wc.vendor_err = 0;
-		wc.qp_num = qp->ibqp.qp_num;
+		wc.qp = &qp->ibqp;
 		wc.src_qp = qp->remote_qpn;
 		wc.pkey_index = 0;
 		wc.slid = qp->remote_ah_attr.dlid;
diff --git a/drivers/infiniband/hw/ipath/ipath_ud.c b/drivers/infiniband/hw/ipath/ipath_ud.c
index 49f1102af8b..9a3e54664ee 100644
--- a/drivers/infiniband/hw/ipath/ipath_ud.c
+++ b/drivers/infiniband/hw/ipath/ipath_ud.c
@@ -66,7 +66,7 @@ bad_lkey:
 	wc.vendor_err = 0;
 	wc.byte_len = 0;
 	wc.imm_data = 0;
-	wc.qp_num = qp->ibqp.qp_num;
+	wc.qp = &qp->ibqp;
 	wc.src_qp = 0;
 	wc.wc_flags = 0;
 	wc.pkey_index = 0;
@@ -255,7 +255,7 @@ static void ipath_ud_loopback(struct ipath_qp *sqp,
 	wc->status = IB_WC_SUCCESS;
 	wc->opcode = IB_WC_RECV;
 	wc->vendor_err = 0;
-	wc->qp_num = qp->ibqp.qp_num;
+	wc->qp = &qp->ibqp;
 	wc->src_qp = sqp->ibqp.qp_num;
 	/* XXX do we know which pkey matched? Only needed for GSI. */
 	wc->pkey_index = 0;
@@ -474,7 +474,7 @@ done:
 		wc.vendor_err = 0;
 		wc.opcode = IB_WC_SEND;
 		wc.byte_len = len;
-		wc.qp_num = qp->ibqp.qp_num;
+		wc.qp = &qp->ibqp;
 		wc.src_qp = 0;
 		wc.wc_flags = 0;
 		/* XXX initialize other fields? */
@@ -651,7 +651,7 @@ void ipath_ud_rcv(struct ipath_ibdev *dev, struct ipath_ib_header *hdr,
 	wc.status = IB_WC_SUCCESS;
 	wc.opcode = IB_WC_RECV;
 	wc.vendor_err = 0;
-	wc.qp_num = qp->ibqp.qp_num;
+	wc.qp = &qp->ibqp;
 	wc.src_qp = src_qp;
 	/* XXX do we know which pkey matched? Only needed for GSI. */
 	wc.pkey_index = 0;
diff --git a/drivers/infiniband/hw/mthca/mthca_cmd.c b/drivers/infiniband/hw/mthca/mthca_cmd.c
index 768df7265b8..968d1519761 100644
--- a/drivers/infiniband/hw/mthca/mthca_cmd.c
+++ b/drivers/infiniband/hw/mthca/mthca_cmd.c
@@ -1854,7 +1854,7 @@ int mthca_MAD_IFC(struct mthca_dev *dev, int ignore_mkey, int ignore_bkey,
 
 		memset(inbox + 256, 0, 256);
 
-		MTHCA_PUT(inbox, in_wc->qp_num,     MAD_IFC_MY_QPN_OFFSET);
+		MTHCA_PUT(inbox, in_wc->qp->qp_num, MAD_IFC_MY_QPN_OFFSET);
 		MTHCA_PUT(inbox, in_wc->src_qp,     MAD_IFC_RQPN_OFFSET);
 
 		val = in_wc->sl << 4;
diff --git a/drivers/infiniband/hw/mthca/mthca_cq.c b/drivers/infiniband/hw/mthca/mthca_cq.c
index 1159c8a0f2c..efd79ef109a 100644
--- a/drivers/infiniband/hw/mthca/mthca_cq.c
+++ b/drivers/infiniband/hw/mthca/mthca_cq.c
@@ -534,7 +534,7 @@ static inline int mthca_poll_one(struct mthca_dev *dev,
 		}
 	}
 
-	entry->qp_num = (*cur_qp)->qpn;
+	entry->qp = &(*cur_qp)->ibqp;
 
 	if (is_send) {
 		wq = &(*cur_qp)->sq;
diff --git a/include/rdma/ib_verbs.h b/include/rdma/ib_verbs.h
index 73aafd7bb50..765589f4d16 100644
--- a/include/rdma/ib_verbs.h
+++ b/include/rdma/ib_verbs.h
@@ -420,8 +420,8 @@ struct ib_wc {
 	enum ib_wc_opcode	opcode;
 	u32			vendor_err;
 	u32			byte_len;
+	struct ib_qp	       *qp;
 	__be32			imm_data;
-	u32			qp_num;
 	u32			src_qp;
 	int			wc_flags;
 	u16			pkey_index;