mpt3sas: combine fw_event_work and its event_data

Tack the firmware reply event_data payload to the end of its
corresponding struct fw_event_work allocation.  This matches the
convention in the mptfusion driver and simplifies the code.

This avoids the following smatch warning:

  drivers/scsi/mpt3sas/mpt3sas_scsih.c:2519
    mpt3sas_send_trigger_data_event() warn: possible memory leak of
    'fw_event'

Signed-off-by: Joe Lawrence <joe.lawrence@stratus.com>
Acked-by: Sreekanth Reddy <Sreekanth.Reddy@avagotech.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

drivers/scsi/mpt3sas/mpt3sas_scsih.c

@@ -190,7 +190,7 @@ struct fw_event_work {
 	u8			VP_ID;
 	u8			ignore;
 	u16			event;
-	void			*event_data;
+	char			event_data[0] __aligned(4);
 };
 
 /* raid transport support */
@@ -2492,7 +2492,6 @@ _scsih_fw_event_free(struct MPT3SAS_ADAPTER *ioc, struct fw_event_work
 
 	spin_lock_irqsave(&ioc->fw_event_lock, flags);
 	list_del(&fw_event->list);
-	kfree(fw_event->event_data);
 	kfree(fw_event);
 	spin_unlock_irqrestore(&ioc->fw_event_lock, flags);
 }
@@ -2513,12 +2512,10 @@ mpt3sas_send_trigger_data_event(struct MPT3SAS_ADAPTER *ioc,
 
 	if (ioc->is_driver_loading)
 		return;
-	fw_event = kzalloc(sizeof(struct fw_event_work), GFP_ATOMIC);
+	fw_event = kzalloc(sizeof(*fw_event) + sizeof(*event_data),
+			   GFP_ATOMIC);
 	if (!fw_event)
 		return;
-	fw_event->event_data = kzalloc(sizeof(*event_data), GFP_ATOMIC);
-	if (!fw_event->event_data)
-		return;
 	fw_event->event = MPT3SAS_PROCESS_TRIGGER_DIAG;
 	fw_event->ioc = ioc;
 	memcpy(fw_event->event_data, event_data, sizeof(*event_data));
@@ -3213,7 +3210,8 @@ _scsih_check_topo_delete_events(struct MPT3SAS_ADAPTER *ioc,
 		if (fw_event->event != MPI2_EVENT_SAS_TOPOLOGY_CHANGE_LIST ||
 		    fw_event->ignore)
 			continue;
-		local_event_data = fw_event->event_data;
+		local_event_data = (Mpi2EventDataSasTopologyChangeList_t *)
+				   fw_event->event_data;
 		if (local_event_data->ExpStatus ==
 		    MPI2_EVENT_SAS_TOPO_ES_ADDED ||
 		    local_event_data->ExpStatus ==
@@ -5045,7 +5043,9 @@ _scsih_sas_topology_change_event(struct MPT3SAS_ADAPTER *ioc,
 	u64 sas_address;
 	unsigned long flags;
 	u8 link_rate, prev_link_rate;
-	Mpi2EventDataSasTopologyChangeList_t *event_data = fw_event->event_data;
+	Mpi2EventDataSasTopologyChangeList_t *event_data =
+		(Mpi2EventDataSasTopologyChangeList_t *)
+		fw_event->event_data;
 
 #ifdef CONFIG_SCSI_MPT3SAS_LOGGING
 	if (ioc->logging_level & MPT_DEBUG_EVENT_WORK_TASK)
@@ -5243,7 +5243,8 @@ _scsih_sas_device_status_change_event(struct MPT3SAS_ADAPTER *ioc,
 	u64 sas_address;
 	unsigned long flags;
 	Mpi2EventDataSasDeviceStatusChange_t *event_data =
-	    fw_event->event_data;
+		(Mpi2EventDataSasDeviceStatusChange_t *)
+		fw_event->event_data;
 
 #ifdef CONFIG_SCSI_MPT3SAS_LOGGING
 	if (ioc->logging_level & MPT_DEBUG_EVENT_WORK_TASK)
@@ -5339,6 +5340,7 @@ _scsih_sas_enclosure_dev_status_change_event(struct MPT3SAS_ADAPTER *ioc,
 #ifdef CONFIG_SCSI_MPT3SAS_LOGGING
 	if (ioc->logging_level & MPT_DEBUG_EVENT_WORK_TASK)
 		_scsih_sas_enclosure_dev_status_change_event_debug(ioc,
+		     (Mpi2EventDataSasEnclDevStatusChange_t *)
 		     fw_event->event_data);
 #endif
 }
@@ -5363,7 +5365,9 @@ _scsih_sas_broadcast_primitive_event(struct MPT3SAS_ADAPTER *ioc,
 	u32 termination_count;
 	u32 query_count;
 	Mpi2SCSITaskManagementReply_t *mpi_reply;
-	Mpi2EventDataSasBroadcastPrimitive_t *event_data = fw_event->event_data;
+	Mpi2EventDataSasBroadcastPrimitive_t *event_data =
+		(Mpi2EventDataSasBroadcastPrimitive_t *)
+		fw_event->event_data;
 	u16 ioc_status;
 	unsigned long flags;
 	int r;
@@ -5515,7 +5519,8 @@ static void
 _scsih_sas_discovery_event(struct MPT3SAS_ADAPTER *ioc,
 	struct fw_event_work *fw_event)
 {
-	Mpi2EventDataSasDiscovery_t *event_data = fw_event->event_data;
+	Mpi2EventDataSasDiscovery_t *event_data =
+		(Mpi2EventDataSasDiscovery_t *) fw_event->event_data;
 
 #ifdef CONFIG_SCSI_MPT3SAS_LOGGING
 	if (ioc->logging_level & MPT_DEBUG_EVENT_WORK_TASK) {
@@ -6001,7 +6006,9 @@ _scsih_sas_ir_config_change_event(struct MPT3SAS_ADAPTER *ioc,
 	Mpi2EventIrConfigElement_t *element;
 	int i;
 	u8 foreign_config;
-	Mpi2EventDataIrConfigChangeList_t *event_data = fw_event->event_data;
+	Mpi2EventDataIrConfigChangeList_t *event_data =
+		(Mpi2EventDataIrConfigChangeList_t *)
+		fw_event->event_data;
 
 #ifdef CONFIG_SCSI_MPT3SAS_LOGGING
 	if (ioc->logging_level & MPT_DEBUG_EVENT_WORK_TASK)
@@ -6071,7 +6078,8 @@ _scsih_sas_ir_volume_event(struct MPT3SAS_ADAPTER *ioc,
 	u16 handle;
 	u32 state;
 	int rc;
-	Mpi2EventDataIrVolume_t *event_data = fw_event->event_data;
+	Mpi2EventDataIrVolume_t *event_data =
+		(Mpi2EventDataIrVolume_t *) fw_event->event_data;
 
 	if (ioc->shost_recovery)
 		return;
@@ -6154,7 +6162,8 @@ _scsih_sas_ir_physical_disk_event(struct MPT3SAS_ADAPTER *ioc,
 	Mpi2ConfigReply_t mpi_reply;
 	Mpi2SasDevicePage0_t sas_device_pg0;
 	u32 ioc_status;
-	Mpi2EventDataIrPhysicalDisk_t *event_data = fw_event->event_data;
+	Mpi2EventDataIrPhysicalDisk_t *event_data =
+		(Mpi2EventDataIrPhysicalDisk_t *) fw_event->event_data;
 	u64 sas_address;
 
 	if (ioc->shost_recovery)
@@ -6274,7 +6283,9 @@ static void
 _scsih_sas_ir_operation_status_event(struct MPT3SAS_ADAPTER *ioc,
 	struct fw_event_work *fw_event)
 {
-	Mpi2EventDataIrOperationStatus_t *event_data = fw_event->event_data;
+	Mpi2EventDataIrOperationStatus_t *event_data =
+		(Mpi2EventDataIrOperationStatus_t *)
+		fw_event->event_data;
 	static struct _raid_device *raid_device;
 	unsigned long flags;
 	u16 handle;
@@ -7036,7 +7047,9 @@ _mpt3sas_fw_work(struct MPT3SAS_ADAPTER *ioc, struct fw_event_work *fw_event)
 
 	switch (fw_event->event) {
 	case MPT3SAS_PROCESS_TRIGGER_DIAG:
-		mpt3sas_process_trigger_data(ioc, fw_event->event_data);
+		mpt3sas_process_trigger_data(ioc,
+			(struct SL_WH_TRIGGERS_EVENT_DATA_T *)
+			fw_event->event_data);
 		break;
 	case MPT3SAS_REMOVE_UNRESPONDING_DEVICES:
 		while (scsi_host_in_recovery(ioc->shost) || ioc->shost_recovery)
@@ -7194,18 +7207,11 @@ mpt3sas_scsih_event_callback(struct MPT3SAS_ADAPTER *ioc, u8 msix_index,
 		return 1;
 	}
 
-	fw_event = kzalloc(sizeof(struct fw_event_work), GFP_ATOMIC);
-	if (!fw_event) {
-		pr_err(MPT3SAS_FMT "failure at %s:%d/%s()!\n",
-		    ioc->name, __FILE__, __LINE__, __func__);
-		return 1;
-	}
 	sz = le16_to_cpu(mpi_reply->EventDataLength) * 4;
-	fw_event->event_data = kzalloc(sz, GFP_ATOMIC);
-	if (!fw_event->event_data) {
+	fw_event = kzalloc(sizeof(*fw_event) + sz, GFP_ATOMIC);
+	if (!fw_event) {
 		pr_err(MPT3SAS_FMT "failure at %s:%d/%s()!\n",
 		    ioc->name, __FILE__, __LINE__, __func__);
-		kfree(fw_event);
 		return 1;
 	}