scsi: mpt3sas: Cache enclosure pages during enclosure add.

In function _scsih_add_device, for each device connected to an
enclosure, driver reads the enclosure page(To get details like enclosure
handle, enclosure logical ID, enclosure level etc.)

With this patch, instead of reading enclosure page everytime, driver
maintains a list for enclosure device(During enclosure add event,
enclosure device is added to the list and removed from the list on
delete events) and uses the enclosure page from the list.

Signed-off-by: Chaitra P B <chaitra.basappa@broadcom.com>
Signed-off-by: Suganath Prabu S <suganath-prabu.subramani@broadcom.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/mpt3sas/mpt3sas_base.c

@@ -4089,6 +4089,27 @@ _base_static_config_pages(struct MPT3SAS_ADAPTER *ioc)
 		ioc->temp_sensors_count = ioc->iounit_pg8.NumSensors;
 }
 
+/**
+ * mpt3sas_free_enclosure_list - release memory
+ * @ioc: per adapter object
+ *
+ * Free memory allocated during encloure add.
+ *
+ * Return nothing.
+ */
+void
+mpt3sas_free_enclosure_list(struct MPT3SAS_ADAPTER *ioc)
+{
+	struct _enclosure_node *enclosure_dev, *enclosure_dev_next;
+
+	/* Free enclosure list */
+	list_for_each_entry_safe(enclosure_dev,
+			enclosure_dev_next, &ioc->enclosure_list, list) {
+		list_del(&enclosure_dev->list);
+		kfree(enclosure_dev);
+	}
+}
+
 /**
  * _base_release_memory_pools - release memory
  * @ioc: per adapter object
@@ -6669,6 +6690,7 @@ mpt3sas_base_detach(struct MPT3SAS_ADAPTER *ioc)
 	mpt3sas_base_stop_watchdog(ioc);
 	mpt3sas_base_free_resources(ioc);
 	_base_release_memory_pools(ioc);
+	mpt3sas_free_enclosure_list(ioc);
 	pci_set_drvdata(ioc->pdev, NULL);
 	kfree(ioc->cpu_msix_table);
 	if (ioc->is_warpdrive)

drivers/scsi/mpt3sas/mpt3sas_base.h

@@ -741,6 +741,17 @@ struct _sas_node {
 	struct list_head sas_port_list;
 };
 
+
+/**
+ * struct _enclosure_node - enclosure information
+ * @list: list of enclosures
+ * @pg0: enclosure pg0;
+ */
+struct _enclosure_node {
+	struct list_head list;
+	Mpi2SasEnclosurePage0_t pg0;
+};
+
 /**
  * enum reset_type - reset state
  * @FORCE_BIG_HAMMER: issue diagnostic reset
@@ -1013,6 +1024,7 @@ typedef void (*MPT3SAS_FLUSH_RUNNING_CMDS)(struct MPT3SAS_ADAPTER *ioc);
  * @iounit_pg8: static iounit page 8
  * @sas_hba: sas host object
  * @sas_expander_list: expander object list
+ * @enclosure_list: enclosure object list
  * @sas_node_lock:
  * @sas_device_list: sas device object list
  * @sas_device_init_list: sas device object list (used only at init time)
@@ -1218,6 +1230,7 @@ struct MPT3SAS_ADAPTER {
 	/* sas hba, expander, and device list */
 	struct _sas_node sas_hba;
 	struct list_head sas_expander_list;
+	struct list_head enclosure_list;
 	spinlock_t	sas_node_lock;
 	struct list_head sas_device_list;
 	struct list_head sas_device_init_list;
@@ -1391,6 +1404,7 @@ int mpt3sas_base_attach(struct MPT3SAS_ADAPTER *ioc);
 void mpt3sas_base_detach(struct MPT3SAS_ADAPTER *ioc);
 int mpt3sas_base_map_resources(struct MPT3SAS_ADAPTER *ioc);
 void mpt3sas_base_free_resources(struct MPT3SAS_ADAPTER *ioc);
+void mpt3sas_free_enclosure_list(struct MPT3SAS_ADAPTER *ioc);
 int mpt3sas_base_hard_reset_handler(struct MPT3SAS_ADAPTER *ioc,
 	enum reset_type type);