IB/mthca: Make all device methods truly reentrant

Documentation/infiniband/core_locking.txt says:

  All of the methods in struct ib_device exported by a low-level
  driver must be fully reentrant.  The low-level driver is required to
  perform all synchronization necessary to maintain consistency, even
  if multiple function calls using the same object are run
  simultaneously.

However, mthca's modify_qp, modify_srq and resize_cq methods are
currently not reentrant.  Add a mutex to the QP, SRQ and CQ structures
so that these calls can be properly serialized.

Signed-off-by: Roland Dreier <rolandd@cisco.com>

1 files changed, 23 insertions, 15 deletions

diff --git a/drivers/infiniband/hw/mthca/mthca_qp.c b/drivers/infiniband/hw/mthca/mthca_qp.c
index 322bc32a93f6..16c387d8170c 100644
--- a/drivers/infiniband/hw/mthca/mthca_qp.c
+++ b/drivers/infiniband/hw/mthca/mthca_qp.c
@@ -536,6 +536,8 @@ int mthca_modify_qp(struct ib_qp *ibqp, struct ib_qp_attr *attr, int attr_mask)
 	u8 status;
 	int err = -EINVAL;
 
+	mutex_lock(&qp->mutex);
+
 	if (attr_mask & IB_QP_CUR_STATE) {
 		cur_state = attr->cur_qp_state;
 	} else {
@@ -553,39 +555,41 @@ int mthca_modify_qp(struct ib_qp *ibqp, struct ib_qp_attr *attr, int attr_mask)
 			  "%d->%d with attr 0x%08x\n",
 			  qp->transport, cur_state, new_state,
 			  attr_mask);
-		return -EINVAL;
+		goto out;
 	}
 
 	if ((attr_mask & IB_QP_PKEY_INDEX) &&
 	     attr->pkey_index >= dev->limits.pkey_table_len) {
 		mthca_dbg(dev, "P_Key index (%u) too large. max is %d\n",
 			  attr->pkey_index, dev->limits.pkey_table_len-1);
-		return -EINVAL;
+		goto out;
 	}
 
 	if ((attr_mask & IB_QP_PORT) &&
 	    (attr->port_num == 0 || attr->port_num > dev->limits.num_ports)) {
 		mthca_dbg(dev, "Port number (%u) is invalid\n", attr->port_num);
-		return -EINVAL;
+		goto out;
 	}
 
 	if (attr_mask & IB_QP_MAX_QP_RD_ATOMIC &&
 	    attr->max_rd_atomic > dev->limits.max_qp_init_rdma) {
 		mthca_dbg(dev, "Max rdma_atomic as initiator %u too large (max is %d)\n",
 			  attr->max_rd_atomic, dev->limits.max_qp_init_rdma);
-		return -EINVAL;
+		goto out;
 	}
 
 	if (attr_mask & IB_QP_MAX_DEST_RD_ATOMIC &&
 	    attr->max_dest_rd_atomic > 1 << dev->qp_table.rdb_shift) {
 		mthca_dbg(dev, "Max rdma_atomic as responder %u too large (max %d)\n",
 			  attr->max_dest_rd_atomic, 1 << dev->qp_table.rdb_shift);
-		return -EINVAL;
+		goto out;
 	}
 
 	mailbox = mthca_alloc_mailbox(dev, GFP_KERNEL);
-	if (IS_ERR(mailbox))
-		return PTR_ERR(mailbox);
+	if (IS_ERR(mailbox)) {
+		err = PTR_ERR(mailbox);
+		goto out;
+	}
 	qp_param = mailbox->buf;
 	qp_context = &qp_param->context;
 	memset(qp_param, 0, sizeof *qp_param);
@@ -618,7 +622,7 @@ int mthca_modify_qp(struct ib_qp *ibqp, struct ib_qp_attr *attr, int attr_mask)
 		if (attr->path_mtu < IB_MTU_256 || attr->path_mtu > IB_MTU_2048) {
 			mthca_dbg(dev, "path MTU (%u) is invalid\n",
 				  attr->path_mtu);
-			goto out;
+			goto out_mailbox;
 		}
 		qp_context->mtu_msgmax = (attr->path_mtu << 5) | 31;
 	}
@@ -672,7 +676,7 @@ int mthca_modify_qp(struct ib_qp *ibqp, struct ib_qp_attr *attr, int attr_mask)
 	if (attr_mask & IB_QP_AV) {
 		if (mthca_path_set(dev, &attr->ah_attr, &qp_context->pri_path,
 				   attr_mask & IB_QP_PORT ? attr->port_num : qp->port))
-			goto out;
+			goto out_mailbox;
 
 		qp_param->opt_param_mask |= cpu_to_be32(MTHCA_QP_OPTPAR_PRIMARY_ADDR_PATH);
 	}
@@ -686,18 +690,18 @@ int mthca_modify_qp(struct ib_qp *ibqp, struct ib_qp_attr *attr, int attr_mask)
 		if (attr->alt_pkey_index >= dev->limits.pkey_table_len) {
 			mthca_dbg(dev, "Alternate P_Key index (%u) too large. max is %d\n",
 				  attr->alt_pkey_index, dev->limits.pkey_table_len-1);
-			goto out;
+			goto out_mailbox;
 		}
 
 		if (attr->alt_port_num == 0 || attr->alt_port_num > dev->limits.num_ports) {
 			mthca_dbg(dev, "Alternate port number (%u) is invalid\n",
 				attr->alt_port_num);
-			goto out;
+			goto out_mailbox;
 		}
 
 		if (mthca_path_set(dev, &attr->alt_ah_attr, &qp_context->alt_path,
 				   attr->alt_ah_attr.port_num))
-			goto out;
+			goto out_mailbox;
 
 		qp_context->alt_path.port_pkey |= cpu_to_be32(attr->alt_pkey_index |
 							      attr->alt_port_num << 24);
@@ -793,12 +797,12 @@ int mthca_modify_qp(struct ib_qp *ibqp, struct ib_qp_attr *attr, int attr_mask)
 	err = mthca_MODIFY_QP(dev, cur_state, new_state, qp->qpn, 0,
 			      mailbox, sqd_event, &status);
 	if (err)
-		goto out;
+		goto out_mailbox;
 	if (status) {
 		mthca_warn(dev, "modify QP %d->%d returned status %02x.\n",
 			   cur_state, new_state, status);
 		err = -EINVAL;
-		goto out;
+		goto out_mailbox;
 	}
 
 	qp->state = new_state;
@@ -853,8 +857,11 @@ int mthca_modify_qp(struct ib_qp *ibqp, struct ib_qp_attr *attr, int attr_mask)
 		}
 	}
 
-out:
+out_mailbox:
 	mthca_free_mailbox(dev, mailbox);
+
+out:
+	mutex_unlock(&qp->mutex);
 	return err;
 }
 
@@ -1100,6 +1107,7 @@ static int mthca_alloc_qp_common(struct mthca_dev *dev,
 
 	qp->refcount = 1;
 	init_waitqueue_head(&qp->wait);
+	mutex_init(&qp->mutex);
 	qp->state    	 = IB_QPS_RESET;
 	qp->atomic_rd_en = 0;
 	qp->resp_depth   = 0;