scsi: qla2xxx: Update BPM enablement semantics.

commit e4e3a2ce9556 ("scsi: qla2xxx: Add ability to autodetect SFP
type") takes a heavy handed approach to BPM (Buffer Plus Management)
enablement:

1) During hardware initialization, if an LR-capable transceiver is
   recognized, the driver schedules a disruptive post-initialization
   chip-reset (ISP-ABORT) to allow the BPM settings to be sent to the
   firmware.  This chip-reset will result in (short-term) path-loss to
   all fc-rports and their attached SCSI devices.

2) LR-detection is triggered during any link-up event, resulting in a
   refresh and potential chip-reset

Based on firmware-team guidance, upon LR-capable transceiver
recognition, the driver's hardware initialization code will now
re-execute firmware with the new BPM settings, then continue on with
driver initialization.  To address the second issue, the driver
performs LR-capable detection upon the driver receiving a
transceiver-insertion asynchronous event from firmware.  No short-term
path loss is needed with this new semantic.

Link: https://lore.kernel.org/r/20200226224022.24518-10-hmadhani@marvell.com
Signed-off-by: Himanshu Madhani <hmadhani@marvell.com>
Signed-off-by: Andrew Vasquez <andrewv@marvell.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

1 files changed, 64 insertions, 26 deletions

diff --git a/drivers/scsi/qla2xxx/qla_init.c b/drivers/scsi/qla2xxx/qla_init.c
index 87b2d62b91f9..3d615cc959cc 100644
--- a/drivers/scsi/qla2xxx/qla_init.c
+++ b/drivers/scsi/qla2xxx/qla_init.c
@@ -3550,53 +3550,77 @@ static void qla2xxx_print_sfp_info(struct scsi_qla_host *vha)
 }
 
 
-/*
- * Return Code:
- *   QLA_SUCCESS: no action
- *   QLA_INTERFACE_ERROR: SFP is not there.
- *   QLA_FUNCTION_FAILED: detected New SFP
+/**
+ * qla24xx_detect_sfp()
+ *
+ * @vha: adapter state pointer.
+ *
+ * @return
+ *	0 -- Configure firmware to use short-range settings -- normal
+ *	     buffer-to-buffer credits.
+ *
+ *	1 -- Configure firmware to use long-range settings -- extra
+ *	     buffer-to-buffer credits should be allocated with
+ *	     ha->lr_distance containing distance settings from NVRAM or SFP
+ *	     (if supported).
  */
 int
 qla24xx_detect_sfp(scsi_qla_host_t *vha)
 {
-	int rc = QLA_SUCCESS;
+	int rc, used_nvram;
 	struct sff_8247_a0 *a;
 	struct qla_hw_data *ha = vha->hw;
-
-	if (!AUTO_DETECT_SFP_SUPPORT(vha))
+	struct nvram_81xx *nv = ha->nvram;
+#define LR_DISTANCE_UNKNOWN	2
+	static const char * const types[] = { "Short", "Long" };
+	static const char * const lengths[] = { "(10km)", "(5km)", "" };
+	u8 ll = 0;
+
+	/* Seed with NVRAM settings. */
+	used_nvram = 0;
+	ha->flags.lr_detected = 0;
+	if (IS_BPM_RANGE_CAPABLE(ha) &&
+	    (nv->enhanced_features & NEF_LR_DIST_ENABLE)) {
+		used_nvram = 1;
+		ha->flags.lr_detected = 1;
+		ha->lr_distance =
+		    (nv->enhanced_features >> LR_DIST_NV_POS)
+		     & LR_DIST_NV_MASK;
+	}
+
+	if (!IS_BPM_ENABLED(vha))
 		goto out;
-
+	/* Determine SR/LR capabilities of SFP/Transceiver. */
 	rc = qla2x00_read_sfp_dev(vha, NULL, 0);
 	if (rc)
 		goto out;
 
+	used_nvram = 0;
 	a = (struct sff_8247_a0 *)vha->hw->sfp_data;
 	qla2xxx_print_sfp_info(vha);
 
-	if (a->fc_ll_cc7 & FC_LL_VL || a->fc_ll_cc7 & FC_LL_L) {
-		/* long range */
-		ha->flags.detected_lr_sfp = 1;
+	ha->flags.lr_detected = 0;
+	ll = a->fc_ll_cc7;
+	if (ll & FC_LL_VL || ll & FC_LL_L) {
+		/* Long range, track length. */
+		ha->flags.lr_detected = 1;
 
 		if (a->length_km > 5 || a->length_100m > 50)
-			ha->long_range_distance = LR_DISTANCE_10K;
+			ha->lr_distance = LR_DISTANCE_10K;
 		else
-			ha->long_range_distance = LR_DISTANCE_5K;
-
-		if (ha->flags.detected_lr_sfp != ha->flags.using_lr_setting)
-			ql_dbg(ql_dbg_async, vha, 0x507b,
-			    "Detected Long Range SFP.\n");
-	} else {
-		/* short range */
-		ha->flags.detected_lr_sfp = 0;
-		if (ha->flags.using_lr_setting)
-			ql_dbg(ql_dbg_async, vha, 0x5084,
-			    "Detected Short Range SFP.\n");
+			ha->lr_distance = LR_DISTANCE_5K;
 	}
 
 	if (!vha->flags.init_done)
 		rc = QLA_SUCCESS;
 out:
-	return rc;
+	ql_dbg(ql_dbg_async, vha, 0x507b,
+	    "SFP detect: %s-Range SFP %s (nvr=%x ll=%x lr=%x lrd=%x).\n",
+	    types[ha->flags.lr_detected],
+	    ha->flags.lr_detected ? lengths[ha->lr_distance] :
+	       lengths[LR_DISTANCE_UNKNOWN],
+	    used_nvram, ll, ha->flags.lr_detected, ha->lr_distance);
+	return ha->flags.lr_detected;
 }
 
 /**
@@ -3614,6 +3638,7 @@ qla2x00_setup_chip(scsi_qla_host_t *vha)
 	struct device_reg_2xxx __iomem *reg = &ha->iobase->isp;
 	unsigned long flags;
 	uint16_t fw_major_version;
+	int done_once = 0;
 
 	if (IS_P3P_TYPE(ha)) {
 		rval = ha->isp_ops->load_risc(vha, &srisc_address);
@@ -3634,6 +3659,7 @@ qla2x00_setup_chip(scsi_qla_host_t *vha)
 
 	qla81xx_mpi_sync(vha);
 
+execute_fw_with_lr:
 	/* Load firmware sequences */
 	rval = ha->isp_ops->load_risc(vha, &srisc_address);
 	if (rval == QLA_SUCCESS) {
@@ -3655,7 +3681,15 @@ qla2x00_setup_chip(scsi_qla_host_t *vha)
 			rval = qla2x00_execute_fw(vha, srisc_address);
 			/* Retrieve firmware information. */
 			if (rval == QLA_SUCCESS) {
-				qla24xx_detect_sfp(vha);
+				/* Enable BPM support? */
+				if (!done_once++ && qla24xx_detect_sfp(vha)) {
+					ql_dbg(ql_dbg_init, vha, 0x00ca,
+					    "Re-starting firmware -- BPM.\n");
+					/* Best-effort - re-init. */
+					ha->isp_ops->reset_chip(vha);
+					ha->isp_ops->chip_diag(vha);
+					goto execute_fw_with_lr;
+				}
 
 				if ((IS_QLA83XX(ha) || IS_QLA27XX(ha) ||
 				    IS_QLA28XX(ha)) &&
@@ -3932,6 +3966,10 @@ qla24xx_update_fw_options(scsi_qla_host_t *vha)
 	if (ql2xrdpenable)
 		ha->fw_options[1] |= ADD_FO1_ENABLE_PUREX_IOCB;
 
+	/* Enable Async 8130/8131 events -- transceiver insertion/removal */
+	if (IS_BPM_RANGE_CAPABLE(ha))
+		ha->fw_options[3] |= BIT_10;
+
 	ql_dbg(ql_dbg_init, vha, 0x00e8,
 	    "%s, add FW options 1-3 = 0x%04x 0x%04x 0x%04x mode %x\n",
 	    __func__, ha->fw_options[1], ha->fw_options[2],