ibmvscs: Add support for fast fail error reporting

Index: b/drivers/scsi/ibmvscsi/ibmvscsi.c
===================================================================
@@ -90,6 +90,7 @@ static int max_channel = 3;
 static int init_timeout = 5;
 static int max_requests = IBMVSCSI_MAX_REQUESTS_DEFAULT;
 static int max_events = IBMVSCSI_MAX_REQUESTS_DEFAULT + 2;
+static int fast_fail = 1;
 
 static struct scsi_transport_template *ibmvscsi_transport_template;
 

@@ -110,6 +111,8 @@ module_param_named(init_timeout, init_ti
 MODULE_PARM_DESC(init_timeout, "Initialization timeout in seconds");
 module_param_named(max_requests, max_requests, int, S_IRUGO);
 MODULE_PARM_DESC(max_requests, "Maximum requests for this adapter");
+module_param_named(fast_fail, fast_fail, int, S_IRUGO | S_IWUSR);
+MODULE_PARM_DESC(fast_fail, "Enable fast fail. [Default=1]");
 
 /* ------------------------------------------------------------
  * Routines for the event pool and event structs

@@ -969,6 +972,67 @@ static int send_srp_login(struct ibmvscs
 };
 
 /**
+ * fast_fail_rsp: - Handle response to MAD enable fast fail
+ * @evt_struct:	srp_event_struct with the response
+ *
+ * Used as a "done" callback by when sending enable fast fail. Gets called
+ * by ibmvscsi_handle_crq()
+ */
+static void fast_fail_rsp(struct srp_event_struct *evt_struct)
+{
+	struct ibmvscsi_host_data *hostdata = evt_struct->hostdata;
+	u8 status = evt_struct->xfer_iu->mad.fast_fail.common.status;
+
+	if (status == VIOSRP_MAD_NOT_SUPPORTED)
+		dev_err(hostdata->dev, "fast_fail not supported in server\n");
+	else if (status == VIOSRP_MAD_FAILED)
+		dev_err(hostdata->dev, "fast_fail request failed\n");
+	else if (status != VIOSRP_MAD_SUCCESS) {
+		dev_err(hostdata->dev, "error 0x%X enabling fast_fail\n",
+			evt_struct->xfer_iu->mad.fast_fail.common.status);
+	}
+
+	send_srp_login(evt_struct->hostdata);
+}
+
+/**
+ * init_host - Start host initialization
+ * @hostdata:	ibmvscsi_host_data of host
+ *
+ * Returns zero if successful.
+ */
+static int init_host(struct ibmvscsi_host_data *hostdata)
+{
+	int rc;
+	unsigned long flags;
+	struct viosrp_fast_fail *fast_fail_mad;
+	struct srp_event_struct *evt_struct;
+
+	if (!fast_fail)
+		return send_srp_login(hostdata);
+
+	evt_struct = get_event_struct(&hostdata->pool);
+
+	if (!evt_struct) {
+		dev_err(hostdata->dev, "couldn't allocate an event for fast fail init!\n");
+		return send_srp_login(hostdata);
+	}
+
+	init_event_struct(evt_struct, fast_fail_rsp,
+			  VIOSRP_MAD_FORMAT, init_timeout);
+
+	fast_fail_mad = &evt_struct->iu.mad.fast_fail;
+	memset(fast_fail_mad, 0, sizeof(*fast_fail_mad));
+	fast_fail_mad->common.type = VIOSSRP_ENABLE_FAST_FAIL;
+	fast_fail_mad->common.length = sizeof(*fast_fail_mad);
+
+	spin_lock_irqsave(hostdata->host->host_lock, flags);
+	rc = ibmvscsi_send_srp_event(evt_struct, hostdata, init_timeout * 2);
+	spin_unlock_irqrestore(hostdata->host->host_lock, flags);
+	return rc;
+}
+
+/**
  * sync_completion: Signal that a synchronous command has completed
  * Note that after returning from this call, the evt_struct is freed.
  * the caller waiting on this completion shouldn't touch the evt_struct

@@ -1281,7 +1345,7 @@ void ibmvscsi_handle_crq(struct viosrp_c
 			if ((rc = ibmvscsi_ops->send_crq(hostdata,
 							 0xC002000000000000LL, 0)) == 0) {
 				/* Now login */
-				send_srp_login(hostdata);
+				init_host(hostdata);
 			} else {
 				dev_err(hostdata->dev, "Unable to send init rsp. rc=%ld\n", rc);
 			}

@@ -1291,7 +1355,7 @@ void ibmvscsi_handle_crq(struct viosrp_c
 			dev_info(hostdata->dev, "partner initialization complete\n");
 
 			/* Now login */
-			send_srp_login(hostdata);
+			init_host(hostdata);
 			break;
 		default:
 			dev_err(hostdata->dev, "unknown crq message type: %d\n", crq->format);

Index: b/drivers/scsi/ibmvscsi/viosrp.h
===================================================================
@@ -86,7 +86,14 @@ enum viosrp_mad_types {
 	VIOSRP_EMPTY_IU_TYPE = 0x01,
 	VIOSRP_ERROR_LOG_TYPE = 0x02,
 	VIOSRP_ADAPTER_INFO_TYPE = 0x03,
-	VIOSRP_HOST_CONFIG_TYPE = 0x04
+	VIOSRP_HOST_CONFIG_TYPE = 0x04,
+	VIOSSRP_ENABLE_FAST_FAIL = 0x08,
+};
+
+enum viosrp_mad_status {
+	VIOSRP_MAD_SUCCESS = 0x00,
+	VIOSRP_MAD_NOT_SUPPORTED = 0xF1,
+	VIOSRP_MAD_FAILED = 0xF7,
 };
 
 /* 

@@ -127,11 +134,16 @@ struct viosrp_host_config {
 	u64 buffer;
 };
 
+struct viosrp_fast_fail {
+	struct mad_common common;
+};
+
 union mad_iu {
 	struct viosrp_empty_iu empty_iu;
 	struct viosrp_error_log error_log;
 	struct viosrp_adapter_info adapter_info;
 	struct viosrp_host_config host_config;
+	struct viosrp_fast_fail fast_fail;
 };
 
 union viosrp_iu {