[PATCH v2] nvmet_fc: Add queue create and delete callbacks in LLDD api

[jsmart2021@gmail.com (jsmart2021@gmail.com)]

From: James Smart <jsmart2021@gmail.com>

To facilitate LLDD resource management on nvme queue creation and
deletion, add optional callbacks queue_create and queue_delete.

Signed-off-by: James Smart <james.smart at broadcom.com>
---
v2: require queue_delete if queue_create entrypoint present

 drivers/nvme/target/fc.c       | 19 ++++++++++++++++++-
 include/linux/nvme-fc-driver.h | 18 ++++++++++++++++++
 2 files changed, 36 insertions(+), 1 deletion(-)

diff --git a/drivers/nvme/target/fc.c b/drivers/nvme/target/fc.c
index da6e5a3722fd..2490c36d410b 100644
--- a/drivers/nvme/target/fc.c
+++ b/drivers/nvme/target/fc.c
@@ -555,6 +555,7 @@ static struct nvmet_fc_tgt_queue *
 nvmet_fc_alloc_target_queue(struct nvmet_fc_tgt_assoc *assoc,
 			u16 qid, u16 sqsize)
 {
+	struct nvmet_fc_tgtport *tgtport = assoc->tgtport;
 	struct nvmet_fc_tgt_queue *queue;
 	unsigned long flags;
 	int ret;
@@ -568,8 +569,14 @@ nvmet_fc_alloc_target_queue(struct nvmet_fc_tgt_assoc *assoc,
 	if (!queue)
 		return NULL;
 
+	if (tgtport->ops->queue_create) {
+		if (tgtport->ops->queue_create(&tgtport->fc_target_port,
+				nvmet_fc_makeconnid(assoc, qid), sqsize))
+			goto out_free_queue;
+	}
+
 	if (!nvmet_fc_tgt_a_get(assoc))
-		goto out_free_queue;
+		goto out_queue_delete;
 
 	queue->fod = (struct nvmet_fc_fcp_iod *)&queue[1];
 	queue->qid = qid;
@@ -601,6 +608,10 @@ nvmet_fc_alloc_target_queue(struct nvmet_fc_tgt_assoc *assoc,
 out_fail_iodlist:
 	nvmet_fc_destroy_fcp_iodlist(assoc->tgtport, queue);
 	nvmet_fc_tgt_a_put(assoc);
+out_queue_delete:
+	if (tgtport->ops->queue_delete)
+		tgtport->ops->queue_delete(&tgtport->fc_target_port,
+				nvmet_fc_makeconnid(assoc, qid), sqsize);
 out_free_queue:
 	kfree(queue);
 	return NULL;
@@ -676,6 +687,11 @@ nvmet_fc_delete_target_queue(struct nvmet_fc_tgt_queue *queue)
 	if (disconnect)
 		nvmet_sq_destroy(&queue->nvme_sq);
 
+	if (tgtport->ops->queue_delete)
+		tgtport->ops->queue_delete(&tgtport->fc_target_port,
+				nvmet_fc_makeconnid(queue->assoc, queue->qid),
+				queue->sqsize);
+
 	nvmet_fc_tgt_q_put(queue);
 }
 
@@ -862,6 +878,7 @@ nvmet_fc_register_targetport(struct nvmet_fc_port_info *pinfo,
 	if (!template->xmt_ls_rsp || !template->fcp_op ||
 	    !template->fcp_abort ||
 	    !template->fcp_req_release || !template->targetport_delete ||
+	    (template->queue_create && !template->queue_delete) ||
 	    !template->max_hw_queues || !template->max_sgl_segments ||
 	    !template->max_dif_sgl_segments || !template->dma_boundary) {
 		ret = -EINVAL;
diff --git a/include/linux/nvme-fc-driver.h b/include/linux/nvme-fc-driver.h
index 8dbf16437bb6..abcefb708008 100644
--- a/include/linux/nvme-fc-driver.h
+++ b/include/linux/nvme-fc-driver.h
@@ -806,6 +806,20 @@ struct nvmet_fc_target_port {
  *       to the LLDD after all operations on the fcp operation are complete.
  *       This may be due to the command completing or upon completion of
  *       abort cleanup.
+ *       Entrypoint is Mandatory.
+ *
+ * @queue_create:  Called by the transport to indicate the creation of an
+ *       nvme queue and to allow the LLDD to allocate resources for the
+ *       queue.
+ *       Returns 0 on successfull allocation of resources for the queue.
+ *       -<errno> on failure.  Failure will result in failure of the
+ *       FC-NVME Create Assocation or Create Connection LS's.
+ *       Entrypoint is Optional.
+ *
+ * @queue_delete:  Called by the transport to indicate the deletion of an
+ *       nvme queue and to allow the LLDD to de-allocate resources for the
+ *       queue.
+ *       Entrypoint is Optional.
  *
  * @max_hw_queues:  indicates the maximum number of hw queues the LLDD
  *       supports for cpu affinitization.
@@ -846,6 +860,10 @@ struct nvmet_fc_target_template {
 				struct nvmefc_tgt_fcp_req *fcpreq);
 	void (*fcp_req_release)(struct nvmet_fc_target_port *tgtport,
 				struct nvmefc_tgt_fcp_req *fcpreq);
+	int (*queue_create)(struct nvmet_fc_target_port *tgtport,
+				u64 connection_id, u16 qsize);
+	void (*queue_delete)(struct nvmet_fc_target_port *tgtport,
+				u64 connection_id, u16 qsize);
 
 	u32	max_hw_queues;
 	u16	max_sgl_segments;
-- 
2.11.0