[SCSI] mvsas: add support for Task collector mode and fixed relative bugs

1. Add support for Task collector mode.
2. Fixed relative collector mode bug:
   - I/O failed when disks is on two ports
   - system hang when hotplug disk
   - system hang when unplug disk during run IO
3. Unlock ap->lock within .lldd_execute_task for direct mode to
   improve performance

Signed-off-by: Xiangliang Yu <yuxiangl@marvell.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
diff --git a/drivers/scsi/mvsas/mv_sas.h b/drivers/scsi/mvsas/mv_sas.h
index 77ddc7c..1367d8b 100644
--- a/drivers/scsi/mvsas/mv_sas.h
+++ b/drivers/scsi/mvsas/mv_sas.h
@@ -3,6 +3,7 @@
  *
  * Copyright 2007 Red Hat, Inc.
  * Copyright 2008 Marvell. <kewei@marvell.com>
+ * Copyright 2009-2011 Marvell. <yuxiangl@marvell.com>
  *
  * This file is licensed under GPLv2.
  *
@@ -67,6 +68,7 @@
 extern struct mvs_info *tgt_mvi;
 extern const struct mvs_dispatch mvs_64xx_dispatch;
 extern const struct mvs_dispatch mvs_94xx_dispatch;
+extern struct kmem_cache *mvs_task_list_cache;
 
 #define DEV_IS_EXPANDER(type)	\
 	((type == EDGE_DEV) || (type == FANOUT_DEV))
@@ -341,6 +343,7 @@
 	dma_addr_t bulk_buffer_dma;
 #define TRASH_BUCKET_SIZE    	0x20000
 #endif
+	void *dma_pool;
 	struct mvs_slot_info slot_info[0];
 };
 
@@ -367,6 +370,11 @@
 	int n_elem;
 };
 
+struct mvs_task_list {
+	struct sas_task *task;
+	struct list_head list;
+};
+
 
 /******************** function prototype *********************/
 void mvs_get_sas_addr(void *buf, u32 buflen);