[PATCH AUTOSEL 5.4 065/108] scsi: qla2xxx: Handle NVME status iocb correctly

[Sasha Levin]

From: Arun Easi <aeasi@xxxxxxxxxxx>

[ Upstream commit 3d582b34992ba2fe4065f01019f0c08d12916faa ]

Certain state flags bit combinations are not checked and not handled
correctly. Plus, do not log a normal underrun situation where there is
no frame drop.

Link: https://lore.kernel.org/r/20200226224022.24518-17-hmadhani@xxxxxxxxxxx
Signed-off-by: Himanshu Madhani <hmadhani@xxxxxxxxxxx>
Signed-off-by: Arun Easi <aeasi@xxxxxxxxxxx>
Signed-off-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/scsi/qla2xxx/qla_isr.c | 47 ++++++++++++++++++++++++++++------
 1 file changed, 39 insertions(+), 8 deletions(-)

diff --git a/drivers/scsi/qla2xxx/qla_isr.c b/drivers/scsi/qla2xxx/qla_isr.c
index 3e9c5768815e5..a69765f396750 100644
--- a/drivers/scsi/qla2xxx/qla_isr.c
+++ b/drivers/scsi/qla2xxx/qla_isr.c
@@ -1868,6 +1868,7 @@ static void qla24xx_nvme_iocb_entry(scsi_qla_host_t *vha, struct req_que *req,
 	struct nvmefc_fcp_req *fd;
 	uint16_t        ret = QLA_SUCCESS;
 	uint16_t	comp_status = le16_to_cpu(sts->comp_status);
+	int		logit = 0;
 
 	iocb = &sp->u.iocb_cmd;
 	fcport = sp->fcport;
@@ -1878,6 +1879,12 @@ static void qla24xx_nvme_iocb_entry(scsi_qla_host_t *vha, struct req_que *req,
 	if (unlikely(iocb->u.nvme.aen_op))
 		atomic_dec(&sp->vha->hw->nvme_active_aen_cnt);
 
+	if (unlikely(comp_status != CS_COMPLETE))
+		logit = 1;
+
+	fd->transferred_length = fd->payload_length -
+	    le32_to_cpu(sts->residual_len);
+
 	/*
 	 * State flags: Bit 6 and 0.
 	 * If 0 is set, we don't care about 6.
@@ -1888,8 +1895,20 @@ static void qla24xx_nvme_iocb_entry(scsi_qla_host_t *vha, struct req_que *req,
 	 */
 	if (!(state_flags & (SF_FCP_RSP_DMA | SF_NVME_ERSP))) {
 		iocb->u.nvme.rsp_pyld_len = 0;
-	} else if ((state_flags & SF_FCP_RSP_DMA)) {
+	} else if ((state_flags & (SF_FCP_RSP_DMA | SF_NVME_ERSP)) ==
+			(SF_FCP_RSP_DMA | SF_NVME_ERSP)) {
+		/* Response already DMA'd to fd->rspaddr. */
 		iocb->u.nvme.rsp_pyld_len = le16_to_cpu(sts->nvme_rsp_pyld_len);
+	} else if ((state_flags & SF_FCP_RSP_DMA)) {
+		/*
+		 * Non-zero value in first 12 bytes of NVMe_RSP IU, treat this
+		 * as an error.
+		 */
+		iocb->u.nvme.rsp_pyld_len = 0;
+		fd->transferred_length = 0;
+		ql_dbg(ql_dbg_io, fcport->vha, 0x307a,
+			"Unexpected values in NVMe_RSP IU.\n");
+		logit = 1;
 	} else if (state_flags & SF_NVME_ERSP) {
 		uint32_t *inbuf, *outbuf;
 		uint16_t iter;
@@ -1912,16 +1931,28 @@ static void qla24xx_nvme_iocb_entry(scsi_qla_host_t *vha, struct req_que *req,
 		iter = iocb->u.nvme.rsp_pyld_len >> 2;
 		for (; iter; iter--)
 			*outbuf++ = swab32(*inbuf++);
-	} else { /* unhandled case */
-	    ql_log(ql_log_warn, fcport->vha, 0x503a,
-		"NVME-%s error. Unhandled state_flags of %x\n",
-		sp->name, state_flags);
 	}
 
-	fd->transferred_length = fd->payload_length -
-	    le32_to_cpu(sts->residual_len);
+	if (state_flags & SF_NVME_ERSP) {
+		struct nvme_fc_ersp_iu *rsp_iu = fd->rspaddr;
+		u32 tgt_xfer_len;
 
-	if (unlikely(comp_status != CS_COMPLETE))
+		tgt_xfer_len = be32_to_cpu(rsp_iu->xfrd_len);
+		if (fd->transferred_length != tgt_xfer_len) {
+			ql_dbg(ql_dbg_io, fcport->vha, 0x3079,
+				"Dropped frame(s) detected (sent/rcvd=%u/%u).\n",
+				tgt_xfer_len, fd->transferred_length);
+			logit = 1;
+		} else if (comp_status == CS_DATA_UNDERRUN) {
+			/*
+			 * Do not log if this is just an underflow and there
+			 * is no data loss.
+			 */
+			logit = 0;
+		}
+	}
+
+	if (unlikely(logit))
 		ql_log(ql_log_warn, fcport->vha, 0x5060,
 		   "NVME-%s ERR Handling - hdl=%x status(%x) tr_len:%x resid=%x  ox_id=%x\n",
 		   sp->name, sp->handle, comp_status,
-- 
2.20.1