IB/mlx4: Fix RESET to RESET and RESET to ERROR transitions

According to the IB spec, a QP can be moved from RESET back to RESET
or to the ERROR state, but mlx4 firmware does not support this and
returns an error if we try.  Fix the RESET to RESET transition by
just returning 0 without doing anything, and fix RESET to ERROR by
moving the QP from RESET to INIT with dummy parameters and then
transitioning from INIT to ERROR.

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

1 files changed, 80 insertions, 35 deletions

diff --git a/drivers/infiniband/hw/mlx4/qp.c b/drivers/infiniband/hw/mlx4/qp.c
index 0cf8b95128f..bd28af5753d 100644
--- a/drivers/infiniband/hw/mlx4/qp.c
+++ b/drivers/infiniband/hw/mlx4/qp.c
@@ -573,7 +573,7 @@ static int to_mlx4_st(enum ib_qp_type type)
 	}
 }
 
-static __be32 to_mlx4_access_flags(struct mlx4_ib_qp *qp, struct ib_qp_attr *attr,
+static __be32 to_mlx4_access_flags(struct mlx4_ib_qp *qp, const struct ib_qp_attr *attr,
 				   int attr_mask)
 {
 	u8 dest_rd_atomic;
@@ -603,7 +603,7 @@ static __be32 to_mlx4_access_flags(struct mlx4_ib_qp *qp, struct ib_qp_attr *att
 	return cpu_to_be32(hw_access_flags);
 }
 
-static void store_sqp_attrs(struct mlx4_ib_sqp *sqp, struct ib_qp_attr *attr,
+static void store_sqp_attrs(struct mlx4_ib_sqp *sqp, const struct ib_qp_attr *attr,
 			    int attr_mask)
 {
 	if (attr_mask & IB_QP_PKEY_INDEX)
@@ -619,7 +619,7 @@ static void mlx4_set_sched(struct mlx4_qp_path *path, u8 port)
 	path->sched_queue = (path->sched_queue & 0xbf) | ((port - 1) << 6);
 }
 
-static int mlx4_set_path(struct mlx4_ib_dev *dev, struct ib_ah_attr *ah,
+static int mlx4_set_path(struct mlx4_ib_dev *dev, const struct ib_ah_attr *ah,
 			 struct mlx4_qp_path *path, u8 port)
 {
 	path->grh_mylmc     = ah->src_path_bits & 0x7f;
@@ -655,14 +655,14 @@ static int mlx4_set_path(struct mlx4_ib_dev *dev, struct ib_ah_attr *ah,
 	return 0;
 }
 
-int mlx4_ib_modify_qp(struct ib_qp *ibqp, struct ib_qp_attr *attr,
-		      int attr_mask, struct ib_udata *udata)
+static int __mlx4_ib_modify_qp(struct ib_qp *ibqp,
+			       const struct ib_qp_attr *attr, int attr_mask,
+			       enum ib_qp_state cur_state, enum ib_qp_state new_state)
 {
 	struct mlx4_ib_dev *dev = to_mdev(ibqp->device);
 	struct mlx4_ib_qp *qp = to_mqp(ibqp);
 	struct mlx4_qp_context *context;
 	enum mlx4_qp_optpar optpar = 0;
-	enum ib_qp_state cur_state, new_state;
 	int sqd_event;
 	int err = -EINVAL;
 
@@ -670,34 +670,6 @@ int mlx4_ib_modify_qp(struct ib_qp *ibqp, struct ib_qp_attr *attr,
 	if (!context)
 		return -ENOMEM;
 
-	mutex_lock(&qp->mutex);
-
-	cur_state = attr_mask & IB_QP_CUR_STATE ? attr->cur_qp_state : qp->state;
-	new_state = attr_mask & IB_QP_STATE ? attr->qp_state : cur_state;
-
-	if (!ib_modify_qp_is_ok(cur_state, new_state, ibqp->qp_type, attr_mask))
-		goto out;
-
-	if ((attr_mask & IB_QP_PKEY_INDEX) &&
-	     attr->pkey_index >= dev->dev->caps.pkey_table_len) {
-		goto out;
-	}
-
-	if ((attr_mask & IB_QP_PORT) &&
-	    (attr->port_num == 0 || attr->port_num > dev->dev->caps.num_ports)) {
-		goto out;
-	}
-
-	if (attr_mask & IB_QP_MAX_QP_RD_ATOMIC &&
-	    attr->max_rd_atomic > dev->dev->caps.max_qp_init_rdma) {
-		goto out;
-	}
-
-	if (attr_mask & IB_QP_MAX_DEST_RD_ATOMIC &&
-	    attr->max_dest_rd_atomic > dev->dev->caps.max_qp_dest_rdma) {
-		goto out;
-	}
-
 	context->flags = cpu_to_be32((to_mlx4_state(new_state) << 28) |
 				     (to_mlx4_st(ibqp->qp_type) << 16));
 	context->flags     |= cpu_to_be32(1 << 8); /* DE? */
@@ -920,11 +892,84 @@ int mlx4_ib_modify_qp(struct ib_qp *ibqp, struct ib_qp_attr *attr,
 	}
 
 out:
-	mutex_unlock(&qp->mutex);
 	kfree(context);
 	return err;
 }
 
+static const struct ib_qp_attr mlx4_ib_qp_attr = { .port_num = 1 };
+static const int mlx4_ib_qp_attr_mask_table[IB_QPT_UD + 1] = {
+		[IB_QPT_UD]  = (IB_QP_PKEY_INDEX		|
+				IB_QP_PORT			|
+				IB_QP_QKEY),
+		[IB_QPT_UC]  = (IB_QP_PKEY_INDEX		|
+				IB_QP_PORT			|
+				IB_QP_ACCESS_FLAGS),
+		[IB_QPT_RC]  = (IB_QP_PKEY_INDEX		|
+				IB_QP_PORT			|
+				IB_QP_ACCESS_FLAGS),
+		[IB_QPT_SMI] = (IB_QP_PKEY_INDEX		|
+				IB_QP_QKEY),
+		[IB_QPT_GSI] = (IB_QP_PKEY_INDEX		|
+				IB_QP_QKEY),
+};
+
+int mlx4_ib_modify_qp(struct ib_qp *ibqp, struct ib_qp_attr *attr,
+		      int attr_mask, struct ib_udata *udata)
+{
+	struct mlx4_ib_dev *dev = to_mdev(ibqp->device);
+	struct mlx4_ib_qp *qp = to_mqp(ibqp);
+	enum ib_qp_state cur_state, new_state;
+	int err = -EINVAL;
+
+	mutex_lock(&qp->mutex);
+
+	cur_state = attr_mask & IB_QP_CUR_STATE ? attr->cur_qp_state : qp->state;
+	new_state = attr_mask & IB_QP_STATE ? attr->qp_state : cur_state;
+
+	if (!ib_modify_qp_is_ok(cur_state, new_state, ibqp->qp_type, attr_mask))
+		goto out;
+
+	if ((attr_mask & IB_QP_PKEY_INDEX) &&
+	     attr->pkey_index >= dev->dev->caps.pkey_table_len) {
+		goto out;
+	}
+
+	if ((attr_mask & IB_QP_PORT) &&
+	    (attr->port_num == 0 || attr->port_num > dev->dev->caps.num_ports)) {
+		goto out;
+	}
+
+	if (attr_mask & IB_QP_MAX_QP_RD_ATOMIC &&
+	    attr->max_rd_atomic > dev->dev->caps.max_qp_init_rdma) {
+		goto out;
+	}
+
+	if (attr_mask & IB_QP_MAX_DEST_RD_ATOMIC &&
+	    attr->max_dest_rd_atomic > dev->dev->caps.max_qp_dest_rdma) {
+		goto out;
+	}
+
+	if (cur_state == new_state && cur_state == IB_QPS_RESET) {
+		err = 0;
+		goto out;
+	}
+
+	if (cur_state == IB_QPS_RESET && new_state == IB_QPS_ERR) {
+		err = __mlx4_ib_modify_qp(ibqp, &mlx4_ib_qp_attr,
+					  mlx4_ib_qp_attr_mask_table[ibqp->qp_type],
+					  IB_QPS_RESET, IB_QPS_INIT);
+		if (err)
+			goto out;
+		cur_state = IB_QPS_INIT;
+	}
+
+	err = __mlx4_ib_modify_qp(ibqp, attr, attr_mask, cur_state, new_state);
+
+out:
+	mutex_unlock(&qp->mutex);
+	return err;
+}
+
 static int build_mlx_header(struct mlx4_ib_sqp *sqp, struct ib_send_wr *wr,
 			    void *wqe)
 {