[PATCH 09/15] lpfc: Added recovery logic for running out of NVMET IO context resources

[James Smart <jsmart2021@gmail.com>]

Previous logic would just drop the IO

Added logic to queue the IO to wait for an IO context resource from an IO
thats already in progress.

Signed-off-by: Dick Kennedy <dick.kennedy@broadcom.com>
Signed-off-by: James Smart <james.smart@broadcom.com>
---
 drivers/scsi/lpfc/lpfc.h         |   1 +
 drivers/scsi/lpfc/lpfc_attr.c    |   6 ++
 drivers/scsi/lpfc/lpfc_crtn.h    |   2 +
 drivers/scsi/lpfc/lpfc_debugfs.c |   6 ++
 drivers/scsi/lpfc/lpfc_init.c    |   2 +
 drivers/scsi/lpfc/lpfc_nvmet.c   | 138 +++++++++++++++++++++++++++++++++------
 drivers/scsi/lpfc/lpfc_sli.c     |   7 +-
 drivers/scsi/lpfc/lpfc_sli4.h    |   6 +-
 8 files changed, 144 insertions(+), 24 deletions(-)

diff --git a/drivers/scsi/lpfc/lpfc.h b/drivers/scsi/lpfc/lpfc.h
index 72641b1d3ab8..c47bde6205c9 100644
--- a/drivers/scsi/lpfc/lpfc.h
+++ b/drivers/scsi/lpfc/lpfc.h
@@ -170,6 +170,7 @@ struct rqb_dmabuf {
 	struct lpfc_dmabuf dbuf;
 	uint16_t total_size;
 	uint16_t bytes_recv;
+	uint16_t idx;
 	struct lpfc_queue *hrq;	  /* ptr to associated Header RQ */
 	struct lpfc_queue *drq;	  /* ptr to associated Data RQ */
 };
diff --git a/drivers/scsi/lpfc/lpfc_attr.c b/drivers/scsi/lpfc/lpfc_attr.c
index ebde2e06fb4b..f60ab7322d6c 100644
--- a/drivers/scsi/lpfc/lpfc_attr.c
+++ b/drivers/scsi/lpfc/lpfc_attr.c
@@ -245,6 +245,12 @@ lpfc_nvme_info_show(struct device *dev, struct device_attribute *attr,
 				atomic_read(&tgtp->xmt_abort_rsp),
 				atomic_read(&tgtp->xmt_abort_rsp_error));
 
+		len += snprintf(buf + len, PAGE_SIZE - len,
+				"IO_CTX: %08x outstanding %08x total %x",
+				phba->sli4_hba.nvmet_ctx_cnt,
+				phba->sli4_hba.nvmet_io_wait_cnt,
+				phba->sli4_hba.nvmet_io_wait_total);
+
 		len +=  snprintf(buf+len, PAGE_SIZE-len, "\n");
 		return len;
 	}
diff --git a/drivers/scsi/lpfc/lpfc_crtn.h b/drivers/scsi/lpfc/lpfc_crtn.h
index cc95abd130b4..8912767e7bc8 100644
--- a/drivers/scsi/lpfc/lpfc_crtn.h
+++ b/drivers/scsi/lpfc/lpfc_crtn.h
@@ -77,6 +77,8 @@ void lpfc_retry_pport_discovery(struct lpfc_hba *);
 void lpfc_release_rpi(struct lpfc_hba *, struct lpfc_vport *, uint16_t);
 int lpfc_init_iocb_list(struct lpfc_hba *phba, int cnt);
 void lpfc_free_iocb_list(struct lpfc_hba *phba);
+int lpfc_post_rq_buffer(struct lpfc_hba *phba, struct lpfc_queue *hrq,
+			struct lpfc_queue *drq, int count, int idx);
 
 void lpfc_mbx_cmpl_local_config_link(struct lpfc_hba *, LPFC_MBOXQ_t *);
 void lpfc_mbx_cmpl_reg_login(struct lpfc_hba *, LPFC_MBOXQ_t *);
diff --git a/drivers/scsi/lpfc/lpfc_debugfs.c b/drivers/scsi/lpfc/lpfc_debugfs.c
index 7284533f4df2..c7d1c9d37a64 100644
--- a/drivers/scsi/lpfc/lpfc_debugfs.c
+++ b/drivers/scsi/lpfc/lpfc_debugfs.c
@@ -842,6 +842,12 @@ lpfc_debugfs_nvmestat_data(struct lpfc_vport *vport, char *buf, int size)
 			}
 			spin_unlock(&phba->sli4_hba.abts_nvme_buf_list_lock);
 		}
+
+		len += snprintf(buf + len, size - len,
+				"IO_CTX: %08x  outstanding %08x total %08x\n",
+				phba->sli4_hba.nvmet_ctx_cnt,
+				phba->sli4_hba.nvmet_io_wait_cnt,
+				phba->sli4_hba.nvmet_io_wait_total);
 	} else {
 		if (!(phba->cfg_enable_fc4_type & LPFC_ENABLE_NVME))
 			return len;
diff --git a/drivers/scsi/lpfc/lpfc_init.c b/drivers/scsi/lpfc/lpfc_init.c
index 53d5ab37a46e..472117eb9257 100644
--- a/drivers/scsi/lpfc/lpfc_init.c
+++ b/drivers/scsi/lpfc/lpfc_init.c
@@ -5825,6 +5825,7 @@ lpfc_sli4_driver_resource_setup(struct lpfc_hba *phba)
 		INIT_LIST_HEAD(&phba->sli4_hba.lpfc_abts_nvme_buf_list);
 		INIT_LIST_HEAD(&phba->sli4_hba.lpfc_abts_nvmet_ctx_list);
 		INIT_LIST_HEAD(&phba->sli4_hba.lpfc_nvmet_ctx_list);
+		INIT_LIST_HEAD(&phba->sli4_hba.lpfc_nvmet_io_wait_list);
 
 		/* Fast-path XRI aborted CQ Event work queue list */
 		INIT_LIST_HEAD(&phba->sli4_hba.sp_nvme_xri_aborted_work_queue);
@@ -5833,6 +5834,7 @@ lpfc_sli4_driver_resource_setup(struct lpfc_hba *phba)
 	/* This abort list used by worker thread */
 	spin_lock_init(&phba->sli4_hba.sgl_list_lock);
 	spin_lock_init(&phba->sli4_hba.nvmet_io_lock);
+	spin_lock_init(&phba->sli4_hba.nvmet_io_wait_lock);
 
 	/*
 	 * Initialize driver internal slow-path work queues
diff --git a/drivers/scsi/lpfc/lpfc_nvmet.c b/drivers/scsi/lpfc/lpfc_nvmet.c
index fcc77ae0c71c..312f54278bd4 100644
--- a/drivers/scsi/lpfc/lpfc_nvmet.c
+++ b/drivers/scsi/lpfc/lpfc_nvmet.c
@@ -158,6 +158,12 @@ void
 lpfc_nvmet_ctxbuf_post(struct lpfc_hba *phba, struct lpfc_nvmet_ctxbuf *ctx_buf)
 {
 	struct lpfc_nvmet_rcv_ctx *ctxp = ctx_buf->context;
+	struct lpfc_nvmet_tgtport *tgtp;
+	struct fc_frame_header *fc_hdr;
+	struct rqb_dmabuf *nvmebuf;
+	struct lpfc_dmabuf *hbufp;
+	uint32_t *payload;
+	uint32_t size, oxid, sid, rc;
 	unsigned long iflag;
 
 	if (ctxp->txrdy) {
@@ -168,6 +174,87 @@ lpfc_nvmet_ctxbuf_post(struct lpfc_hba *phba, struct lpfc_nvmet_ctxbuf *ctx_buf)
 	}
 	ctxp->state = LPFC_NVMET_STE_FREE;
 
+	spin_lock_irqsave(&phba->sli4_hba.nvmet_io_wait_lock, iflag);
+	if (phba->sli4_hba.nvmet_io_wait_cnt) {
+		hbufp = &nvmebuf->hbuf;
+		list_remove_head(&phba->sli4_hba.lpfc_nvmet_io_wait_list,
+				 nvmebuf, struct rqb_dmabuf,
+				 hbuf.list);
+		phba->sli4_hba.nvmet_io_wait_cnt--;
+		spin_unlock_irqrestore(&phba->sli4_hba.nvmet_io_wait_lock,
+				       iflag);
+
+		fc_hdr = (struct fc_frame_header *)(nvmebuf->hbuf.virt);
+		oxid = be16_to_cpu(fc_hdr->fh_ox_id);
+		tgtp = (struct lpfc_nvmet_tgtport *)phba->targetport->private;
+		payload = (uint32_t *)(nvmebuf->dbuf.virt);
+		size = nvmebuf->bytes_recv;
+		sid = sli4_sid_from_fc_hdr(fc_hdr);
+
+		ctxp = (struct lpfc_nvmet_rcv_ctx *)ctx_buf->context;
+		memset(ctxp, 0, sizeof(ctxp->ctx));
+		ctxp->wqeq = NULL;
+		ctxp->txrdy = NULL;
+		ctxp->offset = 0;
+		ctxp->phba = phba;
+		ctxp->size = size;
+		ctxp->oxid = oxid;
+		ctxp->sid = sid;
+		ctxp->state = LPFC_NVMET_STE_RCV;
+		ctxp->entry_cnt = 1;
+		ctxp->flag = 0;
+		ctxp->ctxbuf = ctx_buf;
+		spin_lock_init(&ctxp->ctxlock);
+
+#ifdef CONFIG_SCSI_LPFC_DEBUG_FS
+		if (phba->ktime_on) {
+			ctxp->ts_cmd_nvme = ktime_get_ns();
+			ctxp->ts_isr_cmd = ctxp->ts_cmd_nvme;
+			ctxp->ts_nvme_data = 0;
+			ctxp->ts_data_wqput = 0;
+			ctxp->ts_isr_data = 0;
+			ctxp->ts_data_nvme = 0;
+			ctxp->ts_nvme_status = 0;
+			ctxp->ts_status_wqput = 0;
+			ctxp->ts_isr_status = 0;
+			ctxp->ts_status_nvme = 0;
+		}
+#endif
+		atomic_inc(&tgtp->rcv_fcp_cmd_in);
+		/*
+		 * The calling sequence should be:
+		 * nvmet_fc_rcv_fcp_req->lpfc_nvmet_xmt_fcp_op/cmp- req->done
+		 * lpfc_nvmet_xmt_fcp_op_cmp should free the allocated ctxp.
+		 * When we return from nvmet_fc_rcv_fcp_req, all relevant info
+		 * the NVME command / FC header is stored.
+		 * A buffer has already been reposted for this IO, so just free
+		 * the nvmebuf.
+		 */
+		rc = nvmet_fc_rcv_fcp_req(phba->targetport, &ctxp->ctx.fcp_req,
+					  payload, size);
+
+		/* Process FCP command */
+		if (rc == 0) {
+			atomic_inc(&tgtp->rcv_fcp_cmd_out);
+			nvmebuf->hrq->rqbp->rqb_free_buffer(phba, nvmebuf);
+			return;
+		}
+
+		atomic_inc(&tgtp->rcv_fcp_cmd_drop);
+		lpfc_printf_log(phba, KERN_ERR, LOG_NVME_IOERR,
+				"2582 FCP Drop IO x%x: err x%x: x%x x%x x%x\n",
+				ctxp->oxid, rc,
+				atomic_read(&tgtp->rcv_fcp_cmd_in),
+				atomic_read(&tgtp->rcv_fcp_cmd_out),
+				atomic_read(&tgtp->xmt_fcp_release));
+
+		lpfc_nvmet_defer_release(phba, ctxp);
+		lpfc_nvmet_unsol_fcp_issue_abort(phba, ctxp, sid, oxid);
+		nvmebuf->hrq->rqbp->rqb_free_buffer(phba, nvmebuf);
+		return;
+	}
+	spin_unlock_irqrestore(&phba->sli4_hba.nvmet_io_wait_lock, iflag);
+
 	spin_lock_irqsave(&phba->sli4_hba.nvmet_io_lock, iflag);
 	list_add_tail(&ctx_buf->list,
 		      &phba->sli4_hba.lpfc_nvmet_ctx_list);
@@ -1232,7 +1319,7 @@ lpfc_nvmet_unsol_fcp_buffer(struct lpfc_hba *phba,
 	struct fc_frame_header *fc_hdr;
 	struct lpfc_nvmet_ctxbuf *ctx_buf;
 	uint32_t *payload;
-	uint32_t size, oxid, sid, rc;
+	uint32_t size, oxid, sid, rc, qno;
 	unsigned long iflag;
 #ifdef CONFIG_SCSI_LPFC_DEBUG_FS
 	uint32_t id;
@@ -1257,21 +1344,41 @@ lpfc_nvmet_unsol_fcp_buffer(struct lpfc_hba *phba,
 	}
 	spin_unlock_irqrestore(&phba->sli4_hba.nvmet_io_lock, iflag);
 
+	fc_hdr = (struct fc_frame_header *)(nvmebuf->hbuf.virt);
+	oxid = be16_to_cpu(fc_hdr->fh_ox_id);
+	size = nvmebuf->bytes_recv;
+
+#ifdef CONFIG_SCSI_LPFC_DEBUG_FS
+	if (phba->cpucheck_on & LPFC_CHECK_NVMET_RCV) {
+		id = smp_processor_id();
+		if (id < LPFC_CHECK_CPU_CNT)
+			phba->cpucheck_rcv_io[id]++;
+	}
+#endif
+
+	lpfc_nvmeio_data(phba, "NVMET FCP  RCV: xri x%x sz %d CPU %02x\n",
+			 oxid, size, smp_processor_id());
+
 	if (!ctx_buf) {
-		lpfc_printf_log(phba, KERN_ERR, LOG_NVME_IOERR,
-				"6408 No NVMET ctx Drop IO\n");
-		oxid = 0;
-		size = 0;
-		sid = 0;
-		ctxp = NULL;
-		goto dropit;
+		/* Queue this NVME IO to process later */
+		spin_lock_irqsave(&phba->sli4_hba.nvmet_io_wait_lock, iflag);
+		list_add_tail(&nvmebuf->hbuf.list,
+			      &phba->sli4_hba.lpfc_nvmet_io_wait_list);
+		phba->sli4_hba.nvmet_io_wait_cnt++;
+		phba->sli4_hba.nvmet_io_wait_total++;
+		spin_unlock_irqrestore(&phba->sli4_hba.nvmet_io_wait_lock,
+				       iflag);
+
+		/* Post a brand new DMA buffer to RQ */
+		qno = nvmebuf->idx;
+		lpfc_post_rq_buffer(
+			phba, phba->sli4_hba.nvmet_mrq_hdr[qno],
+			phba->sli4_hba.nvmet_mrq_data[qno], 1, qno);
+		return;
 	}
 
 	tgtp = (struct lpfc_nvmet_tgtport *)phba->targetport->private;
 	payload = (uint32_t *)(nvmebuf->dbuf.virt);
-	fc_hdr = (struct fc_frame_header *)(nvmebuf->hbuf.virt);
-	size = nvmebuf->bytes_recv;
-	oxid = be16_to_cpu(fc_hdr->fh_ox_id);
 	sid = sli4_sid_from_fc_hdr(fc_hdr);
 
 	ctxp = (struct lpfc_nvmet_rcv_ctx *)ctx_buf->context;
@@ -1302,17 +1409,8 @@ lpfc_nvmet_unsol_fcp_buffer(struct lpfc_hba *phba,
 		ctxp->ts_isr_status = 0;
 		ctxp->ts_status_nvme = 0;
 	}
-
-	if (phba->cpucheck_on & LPFC_CHECK_NVMET_RCV) {
-		id = smp_processor_id();
-		if (id < LPFC_CHECK_CPU_CNT)
-			phba->cpucheck_rcv_io[id]++;
-	}
 #endif
 
-	lpfc_nvmeio_data(phba, "NVMET FCP  RCV: xri x%x sz %d CPU %02x\n",
-			 oxid, size, smp_processor_id());
-
 	atomic_inc(&tgtp->rcv_fcp_cmd_in);
 	/*
 	 * The calling sequence should be:
diff --git a/drivers/scsi/lpfc/lpfc_sli.c b/drivers/scsi/lpfc/lpfc_sli.c
index b4ab095deb5d..c8f597f4d49a 100644
--- a/drivers/scsi/lpfc/lpfc_sli.c
+++ b/drivers/scsi/lpfc/lpfc_sli.c
@@ -6513,9 +6513,9 @@ lpfc_set_host_data(struct lpfc_hba *phba, LPFC_MBOXQ_t *mbox)
 		 (phba->hba_flag & HBA_FCOE_MODE) ? "FCoE" : "FC");
 }
 
-static int
+int
 lpfc_post_rq_buffer(struct lpfc_hba *phba, struct lpfc_queue *hrq,
-		    struct lpfc_queue *drq, int count)
+		    struct lpfc_queue *drq, int count, int idx)
 {
 	int rc, i;
 	struct lpfc_rqe hrqe;
@@ -6534,6 +6534,7 @@ lpfc_post_rq_buffer(struct lpfc_hba *phba, struct lpfc_queue *hrq,
 			break;
 		rqb_buffer->hrq = hrq;
 		rqb_buffer->drq = drq;
+		rqb_buffer->idx = idx;
 		list_add_tail(&rqb_buffer->hbuf.list, &rqb_buf_list);
 	}
 	while (!list_empty(&rqb_buf_list)) {
@@ -6985,7 +6986,7 @@ lpfc_sli4_hba_setup(struct lpfc_hba *phba)
 			lpfc_post_rq_buffer(
 				phba, phba->sli4_hba.nvmet_mrq_hdr[i],
 				phba->sli4_hba.nvmet_mrq_data[i],
-				LPFC_NVMET_RQE_DEF_COUNT);
+				LPFC_NVMET_RQE_DEF_COUNT, i);
 		}
 	}
 
diff --git a/drivers/scsi/lpfc/lpfc_sli4.h b/drivers/scsi/lpfc/lpfc_sli4.h
index 3e1ad28e2088..a650308a95c5 100644
--- a/drivers/scsi/lpfc/lpfc_sli4.h
+++ b/drivers/scsi/lpfc/lpfc_sli4.h
@@ -619,13 +619,16 @@ struct lpfc_sli4_hba {
 	uint16_t els_xri_cnt;
 	uint16_t nvmet_xri_cnt;
 	uint16_t nvmet_ctx_cnt;
+	uint16_t nvmet_io_wait_cnt;
+	uint16_t nvmet_io_wait_total;
 	struct list_head lpfc_els_sgl_list;
 	struct list_head lpfc_abts_els_sgl_list;
 	struct list_head lpfc_nvmet_sgl_list;
 	struct list_head lpfc_abts_nvmet_ctx_list;
-	struct list_head lpfc_nvmet_ctx_list;
 	struct list_head lpfc_abts_scsi_buf_list;
 	struct list_head lpfc_abts_nvme_buf_list;
+	struct list_head lpfc_nvmet_ctx_list;
+	struct list_head lpfc_nvmet_io_wait_list;
 	struct lpfc_sglq **lpfc_sglq_active_list;
 	struct list_head lpfc_rpi_hdr_list;
 	unsigned long *rpi_bmask;
@@ -657,6 +660,7 @@ struct lpfc_sli4_hba {
 	spinlock_t abts_scsi_buf_list_lock; /* list of aborted SCSI IOs */
 	spinlock_t sgl_list_lock; /* list of aborted els IOs */
 	spinlock_t nvmet_io_lock;
+	spinlock_t nvmet_io_wait_lock; /* IOs waiting for ctx resources */
 	uint32_t physical_port;
 
 	/* CPU to vector mapping information */
-- 
2.11.0