mtip32xx: Add SRSI support

This patch add support for SRSI(Surprise Removal Surprise Insertion).

Approach:
---------
Surprise Removal:
-----------------
On surprise removal of the device, gendisk, request queue, device index, sysfs
entries, etc are retained as long as device is in use - mounted filesystem,
device opened by an application, etc. The service thread breaks out of the main
while loop, waits for pci remove to exit, and then waits for device to become
free. When there no holders of the device, service thread cleans up the block
and device related stuff and returns.

Surprise Insertion:
-------------------
No change, this scenario follows the normal pci probe() function flow.
Signed-off-by: Asai Thambi S P <asamymuthupa@micron.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

drivers/block/mtip32xx/mtip32xx.h

@@ -140,6 +140,7 @@ enum {
 	MTIP_PF_SVC_THD_ACTIVE_BIT  = 4,
 	MTIP_PF_ISSUE_CMDS_BIT      = 5,
 	MTIP_PF_REBUILD_BIT         = 6,
+	MTIP_PF_SR_CLEANUP_BIT      = 7,
 	MTIP_PF_SVC_THD_STOP_BIT    = 8,
 
 	/* below are bit numbers in 'dd_flag' defined in driver_data */
@@ -147,15 +148,18 @@ enum {
 	MTIP_DDF_REMOVE_PENDING_BIT = 1,
 	MTIP_DDF_OVER_TEMP_BIT      = 2,
 	MTIP_DDF_WRITE_PROTECT_BIT  = 3,
-	MTIP_DDF_STOP_IO      = ((1 << MTIP_DDF_REMOVE_PENDING_BIT) |
-				(1 << MTIP_DDF_SEC_LOCK_BIT) |
-				(1 << MTIP_DDF_OVER_TEMP_BIT) |
-				(1 << MTIP_DDF_WRITE_PROTECT_BIT)),
-
+	MTIP_DDF_REMOVE_DONE_BIT    = 4,
 	MTIP_DDF_CLEANUP_BIT        = 5,
 	MTIP_DDF_RESUME_BIT         = 6,
 	MTIP_DDF_INIT_DONE_BIT      = 7,
 	MTIP_DDF_REBUILD_FAILED_BIT = 8,
+
+	MTIP_DDF_STOP_IO      = ((1 << MTIP_DDF_REMOVE_PENDING_BIT) |
+				(1 << MTIP_DDF_SEC_LOCK_BIT) |
+				(1 << MTIP_DDF_OVER_TEMP_BIT) |
+				(1 << MTIP_DDF_WRITE_PROTECT_BIT) |
+				(1 << MTIP_DDF_REBUILD_FAILED_BIT)),
+
 };
 
 struct smart_attr {
@@ -499,6 +503,8 @@ struct driver_data {
 
 	bool trim_supp; /* flag indicating trim support */
 
+	bool sr;
+
 	int numa_node; /* NUMA support */
 
 	char workq_name[32];
@@ -511,6 +517,8 @@ struct driver_data {
 
 	int isr_binding;
 
+	struct block_device *bdev;
+
 	int unal_qdepth; /* qdepth of unaligned IO queue */
 
 	struct list_head online_list; /* linkage for online list */