IB/core: Introduce Receive Work Queue indirection table

Introduce Receive Work Queue (WQ) indirection table.
This object can be used to spread incoming traffic to different
receive Work Queues.

A Receive WQ indirection table points to variable size of WQs.
This table is given to a QP in downstream patches.
Signed-off-by: Yishai Hadas <yishaih@mellanox.com>
Signed-off-by: Matan Barak <matanb@mellanox.com>
Reviewed-by: Sagi Grimberg <sagi@grimerg.me>
Signed-off-by: Doug Ledford <dledford@redhat.com>

drivers/infiniband/core/verbs.c

@@ -1636,6 +1636,68 @@ int ib_modify_wq(struct ib_wq *wq, struct ib_wq_attr *wq_attr,
 }
 EXPORT_SYMBOL(ib_modify_wq);
 
+/*
+ * ib_create_rwq_ind_table - Creates a RQ Indirection Table.
+ * @device: The device on which to create the rwq indirection table.
+ * @ib_rwq_ind_table_init_attr: A list of initial attributes required to
+ * create the Indirection Table.
+ *
+ * Note: The life time of ib_rwq_ind_table_init_attr->ind_tbl is not less
+ *	than the created ib_rwq_ind_table object and the caller is responsible
+ *	for its memory allocation/free.
+ */
+struct ib_rwq_ind_table *ib_create_rwq_ind_table(struct ib_device *device,
+						 struct ib_rwq_ind_table_init_attr *init_attr)
+{
+	struct ib_rwq_ind_table *rwq_ind_table;
+	int i;
+	u32 table_size;
+
+	if (!device->create_rwq_ind_table)
+		return ERR_PTR(-ENOSYS);
+
+	table_size = (1 << init_attr->log_ind_tbl_size);
+	rwq_ind_table = device->create_rwq_ind_table(device,
+				init_attr, NULL);
+	if (IS_ERR(rwq_ind_table))
+		return rwq_ind_table;
+
+	rwq_ind_table->ind_tbl = init_attr->ind_tbl;
+	rwq_ind_table->log_ind_tbl_size = init_attr->log_ind_tbl_size;
+	rwq_ind_table->device = device;
+	rwq_ind_table->uobject = NULL;
+	atomic_set(&rwq_ind_table->usecnt, 0);
+
+	for (i = 0; i < table_size; i++)
+		atomic_inc(&rwq_ind_table->ind_tbl[i]->usecnt);
+
+	return rwq_ind_table;
+}
+EXPORT_SYMBOL(ib_create_rwq_ind_table);
+
+/*
+ * ib_destroy_rwq_ind_table - Destroys the specified Indirection Table.
+ * @wq_ind_table: The Indirection Table to destroy.
+*/
+int ib_destroy_rwq_ind_table(struct ib_rwq_ind_table *rwq_ind_table)
+{
+	int err, i;
+	u32 table_size = (1 << rwq_ind_table->log_ind_tbl_size);
+	struct ib_wq **ind_tbl = rwq_ind_table->ind_tbl;
+
+	if (atomic_read(&rwq_ind_table->usecnt))
+		return -EBUSY;
+
+	err = rwq_ind_table->device->destroy_rwq_ind_table(rwq_ind_table);
+	if (!err) {
+		for (i = 0; i < table_size; i++)
+			atomic_dec(&ind_tbl[i]->usecnt);
+	}
+
+	return err;
+}
+EXPORT_SYMBOL(ib_destroy_rwq_ind_table);
+
 struct ib_flow *ib_create_flow(struct ib_qp *qp,
 			       struct ib_flow_attr *flow_attr,
 			       int domain)

include/rdma/ib_verbs.h

@@ -1473,6 +1473,21 @@ struct ib_wq_attr {
 	enum	ib_wq_state	curr_wq_state;
 };
 
+struct ib_rwq_ind_table {
+	struct ib_device	*device;
+	struct ib_uobject      *uobject;
+	atomic_t		usecnt;
+	u32		ind_tbl_num;
+	u32		log_ind_tbl_size;
+	struct ib_wq	**ind_tbl;
+};
+
+struct ib_rwq_ind_table_init_attr {
+	u32		log_ind_tbl_size;
+	/* Each entry is a pointer to Receive Work Queue */
+	struct ib_wq	**ind_tbl;
+};
+
 struct ib_qp {
 	struct ib_device       *device;
 	struct ib_pd	       *pd;
@@ -1974,6 +1989,10 @@ struct ib_device {
 						struct ib_wq_attr *attr,
 						u32 wq_attr_mask,
 						struct ib_udata *udata);
+	struct ib_rwq_ind_table *  (*create_rwq_ind_table)(struct ib_device *device,
+							   struct ib_rwq_ind_table_init_attr *init_attr,
+							   struct ib_udata *udata);
+	int                        (*destroy_rwq_ind_table)(struct ib_rwq_ind_table *wq_ind_table);
 	struct ib_dma_mapping_ops   *dma_ops;
 
 	struct module               *owner;
@@ -3224,6 +3243,10 @@ struct ib_wq *ib_create_wq(struct ib_pd *pd,
 int ib_destroy_wq(struct ib_wq *wq);
 int ib_modify_wq(struct ib_wq *wq, struct ib_wq_attr *attr,
 		 u32 wq_attr_mask);
+struct ib_rwq_ind_table *ib_create_rwq_ind_table(struct ib_device *device,
+						 struct ib_rwq_ind_table_init_attr*
+						 wq_ind_table_init_attr);
+int ib_destroy_rwq_ind_table(struct ib_rwq_ind_table *wq_ind_table);
 
 int ib_map_mr_sg(struct ib_mr *mr, struct scatterlist *sg, int sg_nents,
 		 unsigned int *sg_offset, unsigned int page_size);