1 files changed, 39 insertions, 2 deletions

diff --git a/drivers/scsi/mpt2sas/mpt2sas_base.h b/drivers/scsi/mpt2sas/mpt2sas_base.h
index caff8d10cca4..97ea360c6920 100644
--- a/drivers/scsi/mpt2sas/mpt2sas_base.h
+++ b/drivers/scsi/mpt2sas/mpt2sas_base.h
@@ -238,6 +238,7 @@
  * @flags: MPT_TARGET_FLAGS_XXX flags
  * @deleted: target flaged for deletion
  * @tm_busy: target is busy with TM request.
+ * @sdev: The sas_device associated with this target
  */
 struct MPT2SAS_TARGET {
         struct scsi_target *starget;
@@ -248,6 +249,7 @@ struct MPT2SAS_TARGET {
         u32     flags;
         u8      deleted;
         u8      tm_busy;
+        struct _sas_device *sdev;
 };
 
 
@@ -376,8 +378,24 @@ struct _sas_device {
         u8      phy;
         u8      responding;
         u8      pfa_led_on;
+        struct kref refcount;
 };
 
+static inline void sas_device_get(struct _sas_device *s)
+{
+        kref_get(&s->refcount);
+}
+
+static inline void sas_device_free(struct kref *r)
+{
+        kfree(container_of(r, struct _sas_device, refcount));
+}
+
+static inline void sas_device_put(struct _sas_device *s)
+{
+        kref_put(&s->refcount, sas_device_free);
+}
+
 /**
  * struct _raid_device - raid volume link list
  * @list: sas device list
@@ -799,6 +817,12 @@ typedef void (*MPT2SAS_FLUSH_RUNNING_CMDS)(struct MPT2SAS_ADAPTER *ioc);
  * @delayed_tr_list: target reset link list
  * @delayed_tr_volume_list: volume target reset link list
  * @@temp_sensors_count: flag to carry the number of temperature sensors
+ * @pci_access_mutex: Mutex to synchronize ioctl,sysfs show path and
+ * pci resource handling. PCI resource freeing will lead to free
+ * vital hardware/memory resource, which might be in use by cli/sysfs
+ * path functions resulting in Null pointer reference followed by kernel
+ * crash. To avoid the above race condition we use mutex syncrhonization
+ * which ensures the syncrhonization between cli/sysfs_show path
  */
 struct MPT2SAS_ADAPTER {
         struct list_head list;
@@ -1015,6 +1039,7 @@ struct MPT2SAS_ADAPTER {
         u8              mfg_pg10_hide_flag;
         u8              hide_drives;
 
+        struct mutex pci_access_mutex;
 };
 
 typedef u8 (*MPT_CALLBACK)(struct MPT2SAS_ADAPTER *ioc, u16 smid, u8 msix_index,
@@ -1023,6 +1048,17 @@ typedef u8 (*MPT_CALLBACK)(struct MPT2SAS_ADAPTER *ioc, u16 smid, u8 msix_index,
 
 /* base shared API */
 extern struct list_head mpt2sas_ioc_list;
+/* spinlock on list operations over IOCs
+ * Case: when multiple warpdrive cards(IOCs) are in use
+ * Each IOC will added to the ioc list stucture on initialization.
+ * Watchdog threads run at regular intervals to check IOC for any
+ * fault conditions which will trigger the dead_ioc thread to
+ * deallocate pci resource, resulting deleting the IOC netry from list,
+ * this deletion need to protected by spinlock to enusre that
+ * ioc removal is syncrhonized, if not synchronized it might lead to
+ * list_del corruption as the ioc list is traversed in cli path
+ */
+extern spinlock_t gioc_lock;
 void mpt2sas_base_start_watchdog(struct MPT2SAS_ADAPTER *ioc);
 void mpt2sas_base_stop_watchdog(struct MPT2SAS_ADAPTER *ioc);
 
@@ -1095,11 +1131,12 @@ struct _sas_node *mpt2sas_scsih_expander_find_by_handle(struct MPT2SAS_ADAPTER *
     u16 handle);
 struct _sas_node *mpt2sas_scsih_expander_find_by_sas_address(struct MPT2SAS_ADAPTER
     *ioc, u64 sas_address);
-struct _sas_device *mpt2sas_scsih_sas_device_find_by_sas_address(
+struct _sas_device *mpt2sas_get_sdev_by_addr(
+    struct MPT2SAS_ADAPTER *ioc, u64 sas_address);
+struct _sas_device *__mpt2sas_get_sdev_by_addr(
     struct MPT2SAS_ADAPTER *ioc, u64 sas_address);
 
 void mpt2sas_port_enable_complete(struct MPT2SAS_ADAPTER *ioc);
-
 void mpt2sas_scsih_reset_handler(struct MPT2SAS_ADAPTER *ioc, int reset_phase);
 
 /* config shared API */