diff --git a/drivers/scsi/megaraid/mega_common.h b/drivers/scsi/megaraid/mega_common.h
new file mode 100644
index 0000000..18969a4
--- /dev/null
+++ b/drivers/scsi/megaraid/mega_common.h
@@ -0,0 +1,286 @@
+/*
+ *
+ *			Linux MegaRAID device driver
+ *
+ * Copyright (c) 2003-2004  LSI Logic Corporation.
+ *
+ *	   This program is free software; you can redistribute it and/or
+ *	   modify it under the terms of the GNU General Public License
+ *	   as published by the Free Software Foundation; either version
+ *	   2 of the License, or (at your option) any later version.
+ *
+ * FILE		: mega_common.h
+ *
+ * Libaray of common routine used by all low-level megaraid drivers
+ */
+
+#ifndef _MEGA_COMMON_H_
+#define _MEGA_COMMON_H_
+
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <linux/pci.h>
+#include <linux/spinlock.h>
+#include <linux/interrupt.h>
+#include <linux/delay.h>
+#include <linux/blkdev.h>
+#include <linux/list.h>
+#include <linux/version.h>
+#include <linux/moduleparam.h>
+#include <asm/semaphore.h>
+#include <scsi/scsi.h>
+#include <scsi/scsi_cmnd.h>
+#include <scsi/scsi_device.h>
+#include <scsi/scsi_host.h>
+
+
+#define LSI_MAX_CHANNELS		16
+#define LSI_MAX_LOGICAL_DRIVES_64LD	(64+1)
+
+
+/**
+ * scb_t - scsi command control block
+ * @param ccb		: command control block for individual driver
+ * @param list		: list of control blocks
+ * @param gp		: general purpose field for LLDs
+ * @param sno		: all SCBs have a serial number
+ * @param scp		: associated scsi command
+ * @param state		: current state of scb
+ * @param dma_dir	: direction of data transfer
+ * @param dma_type	: transfer with sg list, buffer, or no data transfer
+ * @param dev_channel	: actual channel on the device
+ * @param dev_target	: actual target on the device
+ * @param status	: completion status
+ *
+ * This is our central data structure to issue commands the each driver.
+ * Driver specific data structures are maintained in the ccb field.
+ * scb provides a field 'gp', which can be used by LLD for its own purposes
+ *
+ * dev_channel and dev_target must be initialized with the actual channel and
+ * target on the controller.
+ */
+typedef struct {
+	caddr_t			ccb;
+	struct list_head	list;
+	unsigned long		gp;
+	unsigned int		sno;
+	struct scsi_cmnd	*scp;
+	uint32_t		state;
+	uint32_t		dma_direction;
+	uint32_t		dma_type;
+	uint16_t		dev_channel;
+	uint16_t		dev_target;
+	uint32_t		status;
+} scb_t;
+
+/*
+ * SCB states as it transitions from one state to another
+ */
+#define SCB_FREE	0x0000	/* on the free list */
+#define SCB_ACTIVE	0x0001	/* off the free list */
+#define SCB_PENDQ	0x0002	/* on the pending queue */
+#define SCB_ISSUED	0x0004	/* issued - owner f/w */
+#define SCB_ABORT	0x0008	/* Got an abort for this one */
+#define SCB_RESET	0x0010	/* Got a reset for this one */
+
+/*
+ * DMA types for scb
+ */
+#define MRAID_DMA_NONE	0x0000	/* no data transfer for this command */
+#define MRAID_DMA_WSG	0x0001	/* data transfer using a sg list */
+#define MRAID_DMA_WBUF	0x0002	/* data transfer using a contiguous buffer */
+
+
+/**
+ * struct adapter_t - driver's initialization structure
+ * @param dpc_h			: tasklet handle
+ * @param pdev			: pci configuration pointer for kernel
+ * @param host			: pointer to host structure of mid-layer
+ * @param host_lock		: pointer to appropriate lock
+ * @param lock			: synchronization lock for mid-layer and driver
+ * @param quiescent		: driver is quiescent for now.
+ * @param outstanding_cmds	: number of commands pending in the driver
+ * @param kscb_list		: pointer to the bulk of SCBs pointers for IO
+ * @param kscb_pool		: pool of free scbs for IO
+ * @param kscb_pool_lock	: lock for pool of free scbs
+ * @param pend_list		: pending commands list
+ * @param pend_list_lock	: exlusion lock for pending commands list
+ * @param completed_list	: list of completed commands
+ * @param completed_list_lock	: exclusion lock for list of completed commands
+ * @param sglen			: max sg elements supported
+ * @param device_ids		: to convert kernel device addr to our devices.
+ * @param raid_device		: raid adapter specific pointer
+ * @param max_channel		: maximum channel number supported - inclusive
+ * @param max_target		: max target supported - inclusive
+ * @param max_lun		: max lun supported - inclusive
+ * @param unique_id		: unique identifier for each adapter
+ * @param irq			: IRQ for this adapter
+ * @param ito			: internal timeout value, (-1) means no timeout
+ * @param ibuf			: buffer to issue internal commands
+ * @param ibuf_dma_h		: dma handle for the above buffer
+ * @param uscb_list		: SCB pointers for user cmds, common mgmt module
+ * @param uscb_pool		: pool of SCBs for user commands
+ * @param uscb_pool_lock	: exclusion lock for these SCBs
+ * @param max_cmds		: max outstanding commands
+ * @param fw_version		: firmware version
+ * @param bios_version		: bios version
+ * @param max_cdb_sz		: biggest CDB size supported.
+ * @param ha			: is high availability present - clustering
+ * @param init_id		: initiator ID, the default value should be 7
+ * @param max_sectors		: max sectors per request
+ * @param cmd_per_lun		: max outstanding commands per LUN
+ * @param being_detached	: set when unloading, no more mgmt calls
+ *
+ *
+ * mraid_setup_device_map() can be called anytime after the device map is
+ * available and MRAID_GET_DEVICE_MAP() can be called whenever the mapping is
+ * required, usually from LLD's queue entry point. The formar API sets up the
+ * MRAID_IS_LOGICAL(adapter_t *, struct scsi_cmnd *) to find out if the
+ * device in question is a logical drive.
+ *
+ * quiescent flag should be set by the driver if it is not accepting more
+ * commands
+ *
+ * NOTE: The fields of this structures are placed to minimize cache misses
+ */
+
+// amount of space required to store the bios and firmware version strings
+#define VERSION_SIZE	16
+
+typedef struct {
+	struct tasklet_struct	dpc_h;
+	struct pci_dev		*pdev;
+	struct Scsi_Host	*host;
+	spinlock_t		*host_lock;
+	spinlock_t		lock;
+	uint8_t			quiescent;
+	int			outstanding_cmds;
+	scb_t			*kscb_list;
+	struct list_head	kscb_pool;
+	spinlock_t		kscb_pool_lock;
+	struct list_head	pend_list;
+	spinlock_t		pend_list_lock;
+	struct list_head	completed_list;
+	spinlock_t		completed_list_lock;
+	uint16_t		sglen;
+	int			device_ids[LSI_MAX_CHANNELS]
+					[LSI_MAX_LOGICAL_DRIVES_64LD];
+	caddr_t			raid_device;
+	uint8_t			max_channel;
+	uint16_t		max_target;
+	uint8_t			max_lun;
+
+	uint32_t		unique_id;
+	uint8_t			irq;
+	uint8_t			ito;
+	caddr_t			ibuf;
+	dma_addr_t		ibuf_dma_h;
+	scb_t			*uscb_list;
+	struct list_head	uscb_pool;
+	spinlock_t		uscb_pool_lock;
+	int			max_cmds;
+	uint8_t			fw_version[VERSION_SIZE];
+	uint8_t			bios_version[VERSION_SIZE];
+	uint8_t			max_cdb_sz;
+	uint8_t			ha;
+	uint16_t		init_id;
+	uint16_t		max_sectors;
+	uint16_t		cmd_per_lun;
+	atomic_t		being_detached;
+} adapter_t;
+
+#define SCSI_FREE_LIST_LOCK(adapter)	(&adapter->kscb_pool_lock)
+#define USER_FREE_LIST_LOCK(adapter)	(&adapter->uscb_pool_lock)
+#define PENDING_LIST_LOCK(adapter)	(&adapter->pend_list_lock)
+#define COMPLETED_LIST_LOCK(adapter)	(&adapter->completed_list_lock)
+
+
+// conversion from scsi command
+#define SCP2HOST(scp)			(scp)->device->host	// to host
+#define SCP2HOSTDATA(scp)		SCP2HOST(scp)->hostdata	// to soft state
+#define SCP2CHANNEL(scp)		(scp)->device->channel	// to channel
+#define SCP2TARGET(scp)			(scp)->device->id	// to target
+#define SCP2LUN(scp)			(scp)->device->lun	// to LUN
+
+// generic macro to convert scsi command and host to controller's soft state
+#define SCSIHOST2ADAP(host)	(((caddr_t *)(host->hostdata))[0])
+#define SCP2ADAPTER(scp)	(adapter_t *)SCSIHOST2ADAP(SCP2HOST(scp))
+
+
+/**
+ * MRAID_GET_DEVICE_MAP - device ids
+ * @param adp		- Adapter's soft state
+ * @param scp		- mid-layer scsi command pointer
+ * @param p_chan	- physical channel on the controller
+ * @param target	- target id of the device or logical drive number
+ * @param islogical	- set if the command is for the logical drive
+ *
+ * Macro to retrieve information about device class, logical or physical and
+ * the corresponding physical channel and target or logical drive number
+ **/
+#define MRAID_IS_LOGICAL(adp, scp)	\
+	(SCP2CHANNEL(scp) == (adp)->max_channel) ? 1 : 0
+
+#define MRAID_IS_LOGICAL_SDEV(adp, sdev)	\
+	(sdev->channel == (adp)->max_channel) ? 1 : 0
+
+#define MRAID_GET_DEVICE_MAP(adp, scp, p_chan, target, islogical)	\
+	/*								\
+	 * Is the request coming for the virtual channel		\
+	 */								\
+	islogical = MRAID_IS_LOGICAL(adp, scp);				\
+									\
+	/*								\
+	 * Get an index into our table of drive ids mapping		\
+	 */								\
+	if (islogical) {						\
+		p_chan = 0xFF;						\
+		target =						\
+		(adp)->device_ids[(adp)->max_channel][SCP2TARGET(scp)];	\
+	}								\
+	else {								\
+		p_chan = ((adp)->device_ids[SCP2CHANNEL(scp)]		\
+					[SCP2TARGET(scp)] >> 8) & 0xFF;	\
+		target = ((adp)->device_ids[SCP2CHANNEL(scp)]		\
+					[SCP2TARGET(scp)] & 0xFF);	\
+	}
+
+/*
+ * ### Helper routines ###
+ */
+#define LSI_DBGLVL mraid_debug_level	// each LLD must define a global
+ 					// mraid_debug_level
+
+#ifdef DEBUG
+#if defined (_ASSERT_PANIC)
+#define ASSERT_ACTION	panic
+#else
+#define ASSERT_ACTION	printk
+#endif
+
+#define ASSERT(expression)						\
+	if (!(expression)) {						\
+	ASSERT_ACTION("assertion failed:(%s), file: %s, line: %d:%s\n",	\
+			#expression, __FILE__, __LINE__, __FUNCTION__);	\
+	}
+#else
+#define ASSERT(expression)
+#endif
+
+/*
+ * struct mraid_pci_blk - structure holds DMA memory block info
+ * @param vaddr		: virtual address to a memory block
+ * @param dma_addr	: DMA handle to a memory block
+ *
+ * This structure is filled up for the caller. It is the responsibilty of the
+ * caller to allocate this array big enough to store addresses for all
+ * requested elements
+ */
+struct mraid_pci_blk {
+	caddr_t		vaddr;
+	dma_addr_t	dma_addr;
+};
+
+#endif // _MEGA_COMMON_H_
+
+// vim: set ts=8 sw=8 tw=78: