[SCSI] qla4xxx: added support for host event

Added support to post kernel host event to application using
netlink interface.

Signed-off-by: Vikas Chaudhary <vikas.chaudhary@qlogic.com>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

Author: Vikas Chaudhary

drivers/scsi/qla4xxx/ql4_def.h

@@ -301,7 +301,21 @@ struct ql4_tuple_ddb {
 #define DF_ISNS_DISCOVERED	2	/* Device was discovered via iSNS */
 #define DF_FO_MASKED		3
 
+enum qla4_work_type {
+	QLA4_EVENT_AEN,
+};
 
+struct qla4_work_evt {
+	struct list_head list;
+	enum qla4_work_type type;
+	union {
+		struct {
+			enum iscsi_host_event_code code;
+			uint32_t data_size;
+			uint8_t data[0];
+		} aen;
+	} u;
+};
 
 struct ql82xx_hw_data {
 	/* Offsets for flash/nvram access (set to ~0 if not used). */
@@ -672,6 +686,10 @@ struct scsi_qla_host {
 	uint16_t sec_ddb_idx;
 	int is_reset;
 	uint16_t temperature;
+
+	/* event work list */
+	struct list_head work_list;
+	spinlock_t work_lock;
 };
 
 struct ql4_task_data {

drivers/scsi/qla4xxx/ql4_glbl.h

@@ -181,6 +181,8 @@ int qla4xxx_flash_ddb_change(struct scsi_qla_host *ha, uint32_t fw_ddb_index,
 int qla4xxx_ddb_change(struct scsi_qla_host *ha, uint32_t fw_ddb_index,
 		       struct ddb_entry *ddb_entry, uint32_t state);
 void qla4xxx_build_ddb_list(struct scsi_qla_host *ha, int is_reset);
+int qla4xxx_post_aen_work(struct scsi_qla_host *ha, uint32_t aen_code,
+			  uint32_t data_size, uint8_t *data);
 
 /* BSG Functions */
 int qla4xxx_bsg_request(struct bsg_job *bsg_job);

drivers/scsi/qla4xxx/ql4_isr.c

@@ -576,6 +576,9 @@ static void qla4xxx_isr_decode_mailbox(struct scsi_qla_host * ha,
 				set_bit(DPC_LINK_CHANGED, &ha->dpc_flags);
 
 			ql4_printk(KERN_INFO, ha, "%s: LINK UP\n", __func__);
+			qla4xxx_post_aen_work(ha, ISCSI_EVENT_LINKUP,
+					      sizeof(mbox_sts),
+					      (uint8_t *) mbox_sts);
 			break;
 
 		case MBOX_ASTS_LINK_DOWN:
@@ -584,6 +587,9 @@ static void qla4xxx_isr_decode_mailbox(struct scsi_qla_host * ha,
 				set_bit(DPC_LINK_CHANGED, &ha->dpc_flags);
 
 			ql4_printk(KERN_INFO, ha, "%s: LINK DOWN\n", __func__);
+			qla4xxx_post_aen_work(ha, ISCSI_EVENT_LINKDOWN,
+					      sizeof(mbox_sts),
+					      (uint8_t *) mbox_sts);
 			break;
 
 		case MBOX_ASTS_HEARTBEAT:

drivers/scsi/qla4xxx/ql4_os.c

@@ -2282,6 +2282,10 @@ static void qla4xxx_timer(struct scsi_qla_host *ha)
 		}
 	}
 
+	/* Process any deferred work. */
+	if (!list_empty(&ha->work_list))
+		start_dpc++;
+
 	/* Wakeup the dpc routine for this adapter, if needed. */
 	if (start_dpc ||
 	     test_bit(DPC_RESET_HA, &ha->dpc_flags) ||
@@ -2847,6 +2851,81 @@ void qla4xxx_wake_dpc(struct scsi_qla_host *ha)
 		queue_work(ha->dpc_thread, &ha->dpc_work);
 }
 
+static struct qla4_work_evt *
+qla4xxx_alloc_work(struct scsi_qla_host *ha, uint32_t data_size,
+		   enum qla4_work_type type)
+{
+	struct qla4_work_evt *e;
+	uint32_t size = sizeof(struct qla4_work_evt) + data_size;
+
+	e = kzalloc(size, GFP_ATOMIC);
+	if (!e)
+		return NULL;
+
+	INIT_LIST_HEAD(&e->list);
+	e->type = type;
+	return e;
+}
+
+static void qla4xxx_post_work(struct scsi_qla_host *ha,
+			     struct qla4_work_evt *e)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&ha->work_lock, flags);
+	list_add_tail(&e->list, &ha->work_list);
+	spin_unlock_irqrestore(&ha->work_lock, flags);
+	qla4xxx_wake_dpc(ha);
+}
+
+int qla4xxx_post_aen_work(struct scsi_qla_host *ha,
+			  enum iscsi_host_event_code aen_code,
+			  uint32_t data_size, uint8_t *data)
+{
+	struct qla4_work_evt *e;
+
+	e = qla4xxx_alloc_work(ha, data_size, QLA4_EVENT_AEN);
+	if (!e)
+		return QLA_ERROR;
+
+	e->u.aen.code = aen_code;
+	e->u.aen.data_size = data_size;
+	memcpy(e->u.aen.data, data, data_size);
+
+	qla4xxx_post_work(ha, e);
+
+	return QLA_SUCCESS;
+}
+
+void qla4xxx_do_work(struct scsi_qla_host *ha)
+{
+	struct qla4_work_evt *e, *tmp;
+	unsigned long flags;
+	LIST_HEAD(work);
+
+	spin_lock_irqsave(&ha->work_lock, flags);
+	list_splice_init(&ha->work_list, &work);
+	spin_unlock_irqrestore(&ha->work_lock, flags);
+
+	list_for_each_entry_safe(e, tmp, &work, list) {
+		list_del_init(&e->list);
+
+		switch (e->type) {
+		case QLA4_EVENT_AEN:
+			iscsi_post_host_event(ha->host_no,
+					      &qla4xxx_iscsi_transport,
+					      e->u.aen.code,
+					      e->u.aen.data_size,
+					      e->u.aen.data);
+			break;
+		default:
+			ql4_printk(KERN_WARNING, ha, "event type: 0x%x not "
+				   "supported", e->type);
+		}
+		kfree(e);
+	}
+}
+
 /**
  * qla4xxx_do_dpc - dpc routine
  * @data: in our case pointer to adapter structure
@@ -2878,6 +2957,9 @@ static void qla4xxx_do_dpc(struct work_struct *work)
 		return;
 	}
 
+	/* post events to application */
+	qla4xxx_do_work(ha);
+
 	if (is_qla8022(ha)) {
 		if (test_bit(DPC_HA_UNRECOVERABLE, &ha->dpc_flags)) {
 			qla4_8xxx_idc_lock(ha);
@@ -4450,6 +4532,9 @@ static int __devinit qla4xxx_probe_adapter(struct pci_dev *pdev,
 
 	spin_lock_init(&ha->hardware_lock);
 
+	/* Initialize work list */
+	INIT_LIST_HEAD(&ha->work_list);
+
 	/* Allocate dma buffers */
 	if (qla4xxx_mem_alloc(ha)) {
 		ql4_printk(KERN_WARNING, ha,