scsi: mpt3sas: Sync time periodically between driver and firmware

The controller time currently gets updated with host time during driver
load or when a controller reset is issued. I.e. when host issues the
IOCInit request message to the HBA firmware. This IOCInit message has a
field named 'TimeStamp' with which the host updates the controller time.

Sometimes controller time drifts with respect to the host and it is
difficult to correlate host logs with controller logs. Issuing a controller
reset to sync the time would impact in-flight I/O and is not a viable
option.

Instead the driver now sends an IO_UNIT_CONTROL Request to sync the time
periodically. This is done from the watchdog thread which gets invoked
every second.

The time synchronization interval is specified in the 'TimeSyncInterval'
field in Manufacturing Page11 by the controller:

    TimeSyncInterval - 8 bits
	bits  0-6: Time stamp Synchronization interval value
	bit	7: Time stamp Synchronization interval unit,
		   (if this bit is one then Timestamp Synchronization
		   interval value is specified in terms of hours else
		   Timestamp Synchronization interval value is
		   specified in terms of minutes).

The driver keeps track of the timer using IOC's timestamp_update_count
field. This field value gets incremented whenever the watchdog thread gets
invoked. And whenever this field value is greater than or equal to the Time
Stamp Synchronization interval value, the driver sends the IO_UNIT_CONTROL
Request message to controller to update the time and then it resets the
timestamp_update_count field to zero.

Link: https://lore.kernel.org/r/20201126094311.8686-2-suganath-prabu.subramani@broadcom.com
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Suganath Prabu S <suganath-prabu.subramani@broadcom.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

1 files changed, 13 insertions, 1 deletions

diff --git a/drivers/scsi/mpt3sas/mpt3sas_base.h b/drivers/scsi/mpt3sas/mpt3sas_base.h
index 7dab579dbc20..cc4815c74f69 100644
--- a/drivers/scsi/mpt3sas/mpt3sas_base.h
+++ b/drivers/scsi/mpt3sas/mpt3sas_base.h
@@ -93,6 +93,14 @@
 /* CoreDump: Default timeout */
 #define MPT3SAS_DEFAULT_COREDUMP_TIMEOUT_SECONDS	(15) /*15 seconds*/
 #define MPT3SAS_COREDUMP_LOOP_DONE                     (0xFF)
+#define MPT3SAS_TIMESYNC_TIMEOUT_SECONDS		(10) /* 10 seconds */
+#define MPT3SAS_TIMESYNC_UPDATE_INTERVAL		(900) /* 15 minutes */
+#define MPT3SAS_TIMESYNC_UNIT_MASK			(0x80) /* bit 7 */
+#define MPT3SAS_TIMESYNC_MASK				(0x7F) /* 0 - 6 bits */
+#define SECONDS_PER_MIN					(60)
+#define SECONDS_PER_HOUR				(3600)
+#define MPT3SAS_COREDUMP_LOOP_DONE			(0xFF)
+#define MPI26_SET_IOC_PARAMETER_SYNC_TIMESTAMP		(0x81)
 
 /*
  * Set MPT3SAS_SG_DEPTH value based on user input.
@@ -405,7 +413,7 @@ struct Mpi2ManufacturingPage11_t {
 	u16	HostTraceBufferMaxSizeKB;	/* 50h */
 	u16	HostTraceBufferMinSizeKB;	/* 52h */
 	u8	CoreDumpTOSec;			/* 54h */
-	u8	Reserved8;			/* 55h */
+	u8	TimeSyncInterval;		/* 55h */
 	u16	Reserved9;			/* 56h */
 	__le32	Reserved10;			/* 58h */
 };
@@ -1113,6 +1121,8 @@ typedef void (*MPT3SAS_FLUSH_RUNNING_CMDS)(struct MPT3SAS_ADAPTER *ioc);
  * @cpu_msix_table_sz: table size
  * @total_io_cnt: Gives total IO count, used to load balance the interrupts
  * @ioc_coredump_loop: will have non-zero value when FW is in CoreDump state
+ * @timestamp_update_count: Counter to fire timeSync command
+ * time_sync_interval: Time sync interval read from man page 11
  * @high_iops_outstanding: used to load balance the interrupts
  *				within high iops reply queues
  * @msix_load_balance: Enables load balancing of interrupts across
@@ -1308,6 +1318,8 @@ struct MPT3SAS_ADAPTER {
 	MPT3SAS_FLUSH_RUNNING_CMDS schedule_dead_ioc_flush_running_cmds;
 	u32             non_operational_loop;
 	u8              ioc_coredump_loop;
+	u32		timestamp_update_count;
+	u32		time_sync_interval;
 	atomic64_t      total_io_cnt;
 	atomic64_t	high_iops_outstanding;
 	bool            msix_load_balance;