nvme: add common helpers to allocate and free tagsets

Add common helpers to allocate and tear down the admin and I/O tag sets,
including the special queues allocated with them.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>

drivers/nvme/host/core.c

@@ -4796,6 +4796,108 @@ void nvme_complete_async_event(struct nvme_ctrl *ctrl, __le16 status,
 }
 EXPORT_SYMBOL_GPL(nvme_complete_async_event);
 
+int nvme_alloc_admin_tag_set(struct nvme_ctrl *ctrl, struct blk_mq_tag_set *set,
+		const struct blk_mq_ops *ops, unsigned int flags,
+		unsigned int cmd_size)
+{
+	int ret;
+
+	memset(set, 0, sizeof(*set));
+	set->ops = ops;
+	set->queue_depth = NVME_AQ_MQ_TAG_DEPTH;
+	if (ctrl->ops->flags & NVME_F_FABRICS)
+		set->reserved_tags = NVMF_RESERVED_TAGS;
+	set->numa_node = ctrl->numa_node;
+	set->flags = flags;
+	set->cmd_size = cmd_size;
+	set->driver_data = ctrl;
+	set->nr_hw_queues = 1;
+	set->timeout = NVME_ADMIN_TIMEOUT;
+	ret = blk_mq_alloc_tag_set(set);
+	if (ret)
+		return ret;
+
+	ctrl->admin_q = blk_mq_init_queue(set);
+	if (IS_ERR(ctrl->admin_q)) {
+		ret = PTR_ERR(ctrl->admin_q);
+		goto out_free_tagset;
+	}
+
+	if (ctrl->ops->flags & NVME_F_FABRICS) {
+		ctrl->fabrics_q = blk_mq_init_queue(set);
+		if (IS_ERR(ctrl->fabrics_q)) {
+			ret = PTR_ERR(ctrl->fabrics_q);
+			goto out_cleanup_admin_q;
+		}
+	}
+
+	ctrl->admin_tagset = set;
+	return 0;
+
+out_cleanup_admin_q:
+	blk_mq_destroy_queue(ctrl->fabrics_q);
+out_free_tagset:
+	blk_mq_free_tag_set(ctrl->admin_tagset);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(nvme_alloc_admin_tag_set);
+
+void nvme_remove_admin_tag_set(struct nvme_ctrl *ctrl)
+{
+	blk_mq_destroy_queue(ctrl->admin_q);
+	if (ctrl->ops->flags & NVME_F_FABRICS)
+		blk_mq_destroy_queue(ctrl->fabrics_q);
+	blk_mq_free_tag_set(ctrl->admin_tagset);
+}
+EXPORT_SYMBOL_GPL(nvme_remove_admin_tag_set);
+
+int nvme_alloc_io_tag_set(struct nvme_ctrl *ctrl, struct blk_mq_tag_set *set,
+		const struct blk_mq_ops *ops, unsigned int flags,
+		unsigned int cmd_size)
+{
+	int ret;
+
+	memset(set, 0, sizeof(*set));
+	set->ops = ops;
+	set->queue_depth = ctrl->sqsize + 1;
+	set->reserved_tags = NVMF_RESERVED_TAGS;
+	set->numa_node = ctrl->numa_node;
+	set->flags = flags;
+	set->cmd_size = cmd_size,
+	set->driver_data = ctrl;
+	set->nr_hw_queues = ctrl->queue_count - 1;
+	set->timeout = NVME_IO_TIMEOUT;
+	if (ops->map_queues)
+		set->nr_maps = ctrl->opts->nr_poll_queues ? HCTX_MAX_TYPES : 2;
+	ret = blk_mq_alloc_tag_set(set);
+	if (ret)
+		return ret;
+
+	if (ctrl->ops->flags & NVME_F_FABRICS) {
+		ctrl->connect_q = blk_mq_init_queue(set);
+        	if (IS_ERR(ctrl->connect_q)) {
+			ret = PTR_ERR(ctrl->connect_q);
+			goto out_free_tag_set;
+		}
+	}
+
+	ctrl->tagset = set;
+	return 0;
+
+out_free_tag_set:
+	blk_mq_free_tag_set(set);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(nvme_alloc_io_tag_set);
+
+void nvme_remove_io_tag_set(struct nvme_ctrl *ctrl)
+{
+	if (ctrl->ops->flags & NVME_F_FABRICS)
+		blk_mq_destroy_queue(ctrl->connect_q);
+	blk_mq_free_tag_set(ctrl->tagset);
+}
+EXPORT_SYMBOL_GPL(nvme_remove_io_tag_set);
+
 void nvme_stop_ctrl(struct nvme_ctrl *ctrl)
 {
 	nvme_mpath_stop(ctrl);

drivers/nvme/host/nvme.h

@@ -737,6 +737,14 @@ void nvme_uninit_ctrl(struct nvme_ctrl *ctrl);
 void nvme_start_ctrl(struct nvme_ctrl *ctrl);
 void nvme_stop_ctrl(struct nvme_ctrl *ctrl);
 int nvme_init_ctrl_finish(struct nvme_ctrl *ctrl);
+int nvme_alloc_admin_tag_set(struct nvme_ctrl *ctrl, struct blk_mq_tag_set *set,
+		const struct blk_mq_ops *ops, unsigned int flags,
+		unsigned int cmd_size);
+void nvme_remove_admin_tag_set(struct nvme_ctrl *ctrl);
+int nvme_alloc_io_tag_set(struct nvme_ctrl *ctrl, struct blk_mq_tag_set *set,
+		const struct blk_mq_ops *ops, unsigned int flags,
+		unsigned int cmd_size);
+void nvme_remove_io_tag_set(struct nvme_ctrl *ctrl);
 
 void nvme_remove_namespaces(struct nvme_ctrl *ctrl);