[PATCH v1 2/3] mpi3mr: Add queue-full tracking for operational request queues

[Ranjan Kumar <ranjan.kumar@broadcom.com>]

Track queue-full conditions on operational request queues in the driver.
Record the last host tag returned to the SCSI mid-layer
and count I/Os affected by queue-full conditions.

Signed-off-by: Ranjan Kumar <ranjan.kumar@broadcom.com>
---
 drivers/scsi/mpi3mr/mpi3mr.h    | 12 ++++++++++++
 drivers/scsi/mpi3mr/mpi3mr_fw.c | 16 ++++++++++++++++
 2 files changed, 28 insertions(+)

diff --git a/drivers/scsi/mpi3mr/mpi3mr.h b/drivers/scsi/mpi3mr/mpi3mr.h
index da141c185eef..631a48f7425d 100644
--- a/drivers/scsi/mpi3mr/mpi3mr.h
+++ b/drivers/scsi/mpi3mr/mpi3mr.h
@@ -429,6 +429,14 @@ struct segments {
  * @q_segments: Segment descriptor pointer
  * @q_segment_list: Segment list base virtual address
  * @q_segment_list_dma: Segment list base DMA address
+ * @last_full_host_tag: Hosttag of last IO returned to SML
+ *			due to queue full
+ * @qfull_io_count: Number of IOs returned back to SML
+ *			due to queue full
+ * @qfull_instances: Total queue full occurrences.One occurrence
+ *			starts with queue full detection and ends
+ *			with queue full breaks.
+ *
  */
 struct op_req_qinfo {
 	u16 ci;
@@ -442,6 +450,10 @@ struct op_req_qinfo {
 	struct segments *q_segments;
 	void *q_segment_list;
 	dma_addr_t q_segment_list_dma;
+	u16 last_full_host_tag;
+	u64 qfull_io_count;
+	u32 qfull_instances;
+
 };
 
 /**
diff --git a/drivers/scsi/mpi3mr/mpi3mr_fw.c b/drivers/scsi/mpi3mr/mpi3mr_fw.c
index 58360666fb78..da0d475db01e 100644
--- a/drivers/scsi/mpi3mr/mpi3mr_fw.c
+++ b/drivers/scsi/mpi3mr/mpi3mr_fw.c
@@ -2362,6 +2362,9 @@ static int mpi3mr_create_op_req_q(struct mpi3mr_ioc *mrioc, u16 idx,
 	op_req_q->ci = 0;
 	op_req_q->pi = 0;
 	op_req_q->reply_qid = reply_qid;
+	op_req_q->last_full_host_tag =  MPI3MR_HOSTTAG_INVALID;
+	op_req_q->qfull_io_count =  0;
+	op_req_q->qfull_instances =  0;
 	spin_lock_init(&op_req_q->q_lock);
 
 	if (!op_req_q->q_segments) {
@@ -2549,6 +2552,8 @@ int mpi3mr_op_request_post(struct mpi3mr_ioc *mrioc,
 	u16 req_sz = mrioc->facts.op_req_sz;
 	struct segments *segments = op_req_q->q_segments;
 	struct op_reply_qinfo *op_reply_q = NULL;
+	struct mpi3_scsi_io_request *scsiio_req =
+		(struct mpi3_scsi_io_request *)req;
 
 	reply_qidx = op_req_q->reply_qid - 1;
 	op_reply_q = mrioc->op_reply_qinfo + reply_qidx;
@@ -2566,11 +2571,21 @@ int mpi3mr_op_request_post(struct mpi3mr_ioc *mrioc,
 		mpi3mr_process_op_reply_q(mrioc, mrioc->intr_info[midx].op_reply_q);
 
 		if (mpi3mr_check_req_qfull(op_req_q)) {
+
+			if (op_req_q->last_full_host_tag ==
+			    MPI3MR_HOSTTAG_INVALID)
+				op_req_q->qfull_instances++;
+
+			op_req_q->last_full_host_tag = scsiio_req->host_tag;
+			op_req_q->qfull_io_count++;
 			retval = -EAGAIN;
 			goto out;
 		}
 	}
 
+	if (op_req_q->last_full_host_tag != MPI3MR_HOSTTAG_INVALID)
+		op_req_q->last_full_host_tag = MPI3MR_HOSTTAG_INVALID;
+
 	if (mrioc->reset_in_progress) {
 		ioc_err(mrioc, "OpReqQ submit reset in progress\n");
 		retval = -EAGAIN;
@@ -4829,6 +4844,7 @@ void mpi3mr_memset_buffers(struct mpi3mr_ioc *mrioc)
 			mrioc->req_qinfo[i].qid = 0;
 			mrioc->req_qinfo[i].reply_qid = 0;
 			spin_lock_init(&mrioc->req_qinfo[i].q_lock);
+			mrioc->req_qinfo[i].last_full_host_tag = 0;
 			mpi3mr_memset_op_req_q_buffers(mrioc, i);
 		}
 	}
-- 
2.47.3