scsi: qla2xxx: Add support for ZIO6 interrupt threshold

Add sysfs support to control zio6 interrupt threshold. Using this sysfs hook
user can set when to generate interrupts. This value will be used to tell
firmware to generate interrupt at a certain interval.  If the number of
exchanges/commands fall below defined setting, then the interrupt will be
generated immediately by the firmware.

By default ZIO6 will coalesce interrupts to a specified interval
regardless of low traffic or high traffic.

[mkp: fixed several typos]
Signed-off-by: Quinn Tran <quinn.tran@cavium.com>
Signed-off-by: Himanshu Madhani <himanshu.madhani@cavium.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/qla2xxx/qla_attr.c

@@ -1207,6 +1207,34 @@ qla2x00_zio_timer_store(struct device *dev, struct device_attribute *attr,
 	return strlen(buf);
 }
 
+static ssize_t
+qla_zio_threshold_show(struct device *dev, struct device_attribute *attr,
+		       char *buf)
+{
+	scsi_qla_host_t *vha = shost_priv(class_to_shost(dev));
+
+	return scnprintf(buf, PAGE_SIZE, "%d exchanges\n",
+	    vha->hw->last_zio_threshold);
+}
+
+static ssize_t
+qla_zio_threshold_store(struct device *dev, struct device_attribute *attr,
+    const char *buf, size_t count)
+{
+	scsi_qla_host_t *vha = shost_priv(class_to_shost(dev));
+	int val = 0;
+
+	if (vha->hw->zio_mode != QLA_ZIO_MODE_6)
+		return -EINVAL;
+	if (sscanf(buf, "%d", &val) != 1)
+		return -EINVAL;
+	if (val > 256)
+		return -ERANGE;
+
+	atomic_set(&vha->hw->zio_threshold, val);
+	return strlen(buf);
+}
+
 static ssize_t
 qla2x00_beacon_show(struct device *dev, struct device_attribute *attr,
 		    char *buf)
@@ -1651,6 +1679,9 @@ static DEVICE_ATTR(allow_cna_fw_dump, S_IRUGO | S_IWUSR,
 static DEVICE_ATTR(pep_version, S_IRUGO, qla2x00_pep_version_show, NULL);
 static DEVICE_ATTR(min_link_speed, S_IRUGO, qla2x00_min_link_speed_show, NULL);
 static DEVICE_ATTR(max_speed_sup, S_IRUGO, qla2x00_max_speed_sup_show, NULL);
+static DEVICE_ATTR(zio_threshold, 0644,
+    qla_zio_threshold_show,
+    qla_zio_threshold_store);
 
 struct device_attribute *qla2x00_host_attrs[] = {
 	&dev_attr_driver_version,
@@ -1687,6 +1718,7 @@ struct device_attribute *qla2x00_host_attrs[] = {
 	&dev_attr_pep_version,
 	&dev_attr_min_link_speed,
 	&dev_attr_max_speed_sup,
+	&dev_attr_zio_threshold,
 	NULL,
 };
 

drivers/scsi/qla2xxx/qla_def.h

@@ -4190,6 +4190,10 @@ struct qla_hw_data {
 
 	atomic_t        nvme_active_aen_cnt;
 	uint16_t        nvme_last_rptd_aen;             /* Last recorded aen count */
+
+	atomic_t zio_threshold;
+	uint16_t last_zio_threshold;
+#define DEFAULT_ZIO_THRESHOLD 64
 };
 
 #define FW_ABILITY_MAX_SPEED_MASK	0xFUL
@@ -4269,10 +4273,11 @@ typedef struct scsi_qla_host {
 #define FX00_CRITEMP_RECOVERY	25
 #define FX00_HOST_INFO_RESEND	26
 #define QPAIR_ONLINE_CHECK_NEEDED	27
-#define SET_ZIO_THRESHOLD_NEEDED	28
+#define SET_NVME_ZIO_THRESHOLD_NEEDED	28
 #define DETECT_SFP_CHANGE	29
 #define N2N_LOGIN_NEEDED	30
 #define IOCB_WORK_ACTIVE	31
+#define SET_ZIO_THRESHOLD_NEEDED 32
 
 	unsigned long	pci_flags;
 #define PFLG_DISCONNECTED	0	/* PCI device removed */

drivers/scsi/qla2xxx/qla_init.c

@@ -3532,6 +3532,11 @@ qla2x00_setup_chip(scsi_qla_host_t *vha)
 			if (rval == QLA_SUCCESS) {
 				qla24xx_detect_sfp(vha);
 
+				if ((IS_QLA83XX(ha) || IS_QLA27XX(ha)) &&
+				    (ha->zio_mode == QLA_ZIO_MODE_6))
+					qla27xx_set_zio_threshold(vha,
+					    ha->last_zio_threshold);
+
 				rval = qla2x00_set_exlogins_buffer(vha);
 				if (rval != QLA_SUCCESS)
 					goto failed;

drivers/scsi/qla2xxx/qla_mbx.c

@@ -60,6 +60,7 @@ static struct rom_cmd {
 	{ MBC_GET_ADAPTER_LOOP_ID },
 	{ MBC_READ_SFP },
 	{ MBC_GET_RNID_PARAMS },
+	{ MBC_GET_SET_ZIO_THRESHOLD },
 };
 
 static int is_rom_cmd(uint16_t cmd)

drivers/scsi/qla2xxx/qla_os.c

@@ -2840,6 +2840,8 @@ qla2x00_probe_one(struct pci_dev *pdev, const struct pci_device_id *id)
 	atomic_set(&ha->num_pend_mbx_stage1, 0);
 	atomic_set(&ha->num_pend_mbx_stage2, 0);
 	atomic_set(&ha->num_pend_mbx_stage3, 0);
+	atomic_set(&ha->zio_threshold, DEFAULT_ZIO_THRESHOLD);
+	ha->last_zio_threshold = DEFAULT_ZIO_THRESHOLD;
 
 	/* Assign ISP specific operations. */
 	if (IS_QLA2100(ha)) {
@@ -6224,17 +6226,28 @@ qla2x00_do_dpc(void *data)
 			mutex_unlock(&ha->mq_lock);
 		}
 
-		if (test_and_clear_bit(SET_ZIO_THRESHOLD_NEEDED, &base_vha->dpc_flags)) {
+		if (test_and_clear_bit(SET_NVME_ZIO_THRESHOLD_NEEDED,
+		    &base_vha->dpc_flags)) {
 			ql_log(ql_log_info, base_vha, 0xffffff,
 				"nvme: SET ZIO Activity exchange threshold to %d.\n",
 						ha->nvme_last_rptd_aen);
-			if (qla27xx_set_zio_threshold(base_vha, ha->nvme_last_rptd_aen)) {
+			if (qla27xx_set_zio_threshold(base_vha,
+			    ha->nvme_last_rptd_aen)) {
 				ql_log(ql_log_info, base_vha, 0xffffff,
-					"nvme: Unable to SET ZIO Activity exchange threshold to %d.\n",
-						ha->nvme_last_rptd_aen);
+				    "nvme: Unable to SET ZIO Activity exchange threshold to %d.\n",
+				    ha->nvme_last_rptd_aen);
 			}
 		}
 
+		if (test_and_clear_bit(SET_ZIO_THRESHOLD_NEEDED,
+		    &base_vha->dpc_flags)) {
+			ql_log(ql_log_info, base_vha, 0xffffff,
+			    "SET ZIO Activity exchange threshold to %d.\n",
+			    ha->last_zio_threshold);
+			qla27xx_set_zio_threshold(base_vha,
+			    ha->last_zio_threshold);
+		}
+
 		if (!IS_QLAFX00(ha))
 			qla2x00_do_dpc_all_vps(base_vha);
 
@@ -6447,13 +6460,24 @@ qla2x00_timer(struct timer_list *t)
 	 * FC-NVME
 	 * see if the active AEN count has changed from what was last reported.
 	 */
-	if (!vha->vp_idx &&
-		atomic_read(&ha->nvme_active_aen_cnt) != ha->nvme_last_rptd_aen &&
-		ha->zio_mode == QLA_ZIO_MODE_6) {
+	if (!vha->vp_idx && (atomic_read(&ha->nvme_active_aen_cnt) !=
+	    ha->nvme_last_rptd_aen) && ha->zio_mode == QLA_ZIO_MODE_6) {
 		ql_log(ql_log_info, vha, 0x3002,
-			"nvme: Sched: Set ZIO exchange threshold to %d.\n",
-			ha->nvme_last_rptd_aen);
+		    "nvme: Sched: Set ZIO exchange threshold to %d.\n",
+		    ha->nvme_last_rptd_aen);
 		ha->nvme_last_rptd_aen = atomic_read(&ha->nvme_active_aen_cnt);
+		set_bit(SET_NVME_ZIO_THRESHOLD_NEEDED, &vha->dpc_flags);
+		start_dpc++;
+	}
+
+	if (!vha->vp_idx &&
+	    (atomic_read(&ha->zio_threshold) != ha->last_zio_threshold) &&
+	    (ha->zio_mode == QLA_ZIO_MODE_6) &&
+	    (IS_QLA83XX(ha) || IS_QLA27XX(ha))) {
+		ql_log(ql_log_info, vha, 0x3002,
+		    "Sched: Set ZIO exchange threshold to %d.\n",
+		    ha->last_zio_threshold);
+		ha->last_zio_threshold = atomic_read(&ha->zio_threshold);
 		set_bit(SET_ZIO_THRESHOLD_NEEDED, &vha->dpc_flags);
 		start_dpc++;
 	}

drivers/scsi/qla2xxx/qla_target.c

@@ -7052,14 +7052,6 @@ qlt_24xx_config_nvram_stage2(struct scsi_qla_host *vha,
 		memcpy(icb->node_name, ha->tgt.tgt_node_name, WWN_SIZE);
 		icb->firmware_options_1 |= cpu_to_le32(BIT_14);
 	}
-
-	/* disable ZIO at start time. */
-	if (!vha->flags.init_done) {
-		uint32_t tmp;
-		tmp = le32_to_cpu(icb->firmware_options_2);
-		tmp &= ~(BIT_3 | BIT_2 | BIT_1 | BIT_0);
-		icb->firmware_options_2 = cpu_to_le32(tmp);
-	}
 }
 
 void
@@ -7163,15 +7155,6 @@ qlt_81xx_config_nvram_stage2(struct scsi_qla_host *vha,
 		memcpy(icb->node_name, ha->tgt.tgt_node_name, WWN_SIZE);
 		icb->firmware_options_1 |= cpu_to_le32(BIT_14);
 	}
-
-	/* disable ZIO at start time. */
-	if (!vha->flags.init_done) {
-		uint32_t tmp;
-		tmp = le32_to_cpu(icb->firmware_options_2);
-		tmp &= ~(BIT_3 | BIT_2 | BIT_1 | BIT_0);
-		icb->firmware_options_2 = cpu_to_le32(tmp);
-	}
-
 }
 
 void