[PATCH rdma-next 2/4] RDMA/core: Introduce ib_get_qp_err_syndrome function

[Patrisious Haddad <phaddad@nvidia.com>]

Introduce ib_get_qp_err_syndrome function, which enables kernel
applications to query the reason the QP moved to error state.
Even in cases in which no CQE was generated.

Signed-off-by: Patrisious Haddad <phaddad@nvidia.com>
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
---
 drivers/infiniband/core/device.c |  1 +
 drivers/infiniband/core/verbs.c  |  8 ++++++++
 include/rdma/ib_verbs.h          | 13 +++++++++++++
 3 files changed, 22 insertions(+)

diff --git a/drivers/infiniband/core/device.c b/drivers/infiniband/core/device.c
index ae60c73babcc..8235b8fa1100 100644
--- a/drivers/infiniband/core/device.c
+++ b/drivers/infiniband/core/device.c
@@ -2657,6 +2657,7 @@ void ib_set_device_ops(struct ib_device *dev, const struct ib_device_ops *ops)
 	SET_DEVICE_OP(dev_ops, get_netdev);
 	SET_DEVICE_OP(dev_ops, get_numa_node);
 	SET_DEVICE_OP(dev_ops, get_port_immutable);
+	SET_DEVICE_OP(dev_ops, get_qp_err_syndrome);
 	SET_DEVICE_OP(dev_ops, get_vector_affinity);
 	SET_DEVICE_OP(dev_ops, get_vf_config);
 	SET_DEVICE_OP(dev_ops, get_vf_guid);
diff --git a/drivers/infiniband/core/verbs.c b/drivers/infiniband/core/verbs.c
index e54b3f1b730e..ac20af8be33a 100644
--- a/drivers/infiniband/core/verbs.c
+++ b/drivers/infiniband/core/verbs.c
@@ -1952,6 +1952,14 @@ int ib_query_qp(struct ib_qp *qp,
 }
 EXPORT_SYMBOL(ib_query_qp);
 
+int ib_get_qp_err_syndrome(struct ib_qp *qp, char *str)
+{
+	return qp->device->ops.get_qp_err_syndrome ?
+		qp->device->ops.get_qp_err_syndrome(qp->real_qp,
+						    str) : -EOPNOTSUPP;
+}
+EXPORT_SYMBOL(ib_get_qp_err_syndrome);
+
 int ib_close_qp(struct ib_qp *qp)
 {
 	struct ib_qp *real_qp;
diff --git a/include/rdma/ib_verbs.h b/include/rdma/ib_verbs.h
index 975d6e9efbcb..9a94f2ef993c 100644
--- a/include/rdma/ib_verbs.h
+++ b/include/rdma/ib_verbs.h
@@ -2465,6 +2465,7 @@ struct ib_device_ops {
 			 int qp_attr_mask, struct ib_udata *udata);
 	int (*query_qp)(struct ib_qp *qp, struct ib_qp_attr *qp_attr,
 			int qp_attr_mask, struct ib_qp_init_attr *qp_init_attr);
+	int (*get_qp_err_syndrome)(struct ib_qp *qp, char *str);
 	int (*destroy_qp)(struct ib_qp *qp, struct ib_udata *udata);
 	int (*create_cq)(struct ib_cq *cq, const struct ib_cq_init_attr *attr,
 			 struct ib_udata *udata);
@@ -3777,6 +3778,18 @@ int ib_query_qp(struct ib_qp *qp,
 		int qp_attr_mask,
 		struct ib_qp_init_attr *qp_init_attr);
 
+#define IB_ERR_SYNDROME_LENGTH 256
+
+/**
+ * ib_get_qp_err_syndrome - Returns a string that describes the reason
+ * the specified QP moved to error state.
+ * @qp : The QP to query.
+ * @str: The reason the qp moved to error state.
+ *
+ * NOTE: the user must pass a str with size of at least IB_ERR_SYNDROME_LENGTH
+ */
+int ib_get_qp_err_syndrome(struct ib_qp *qp, char *str);
+
 /**
  * ib_destroy_qp - Destroys the specified QP.
  * @qp: The QP to destroy.
-- 
2.18.1