FreeBSD-5.3/sys/dev/twe/twereg.h
/*-
* Copyright (c) 2000 Michael Smith
* Copyright (c) 2003 Paul Saab
* Copyright (c) 2003 Vinod Kashyap
* Copyright (c) 2000 BSDi
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD: src/sys/dev/twe/twereg.h,v 1.11 2004/05/12 04:10:37 vkashyap Exp $
*/
/*
* Register names, bit definitions, structure names and members are
* identical with those in the Linux driver where possible and sane
* for simplicity's sake. (The TW_ prefix has become TWE_)
* Some defines that are clearly irrelevant to FreeBSD have been
* removed.
*/
/* control register bit definitions */
#define TWE_CONTROL_CLEAR_HOST_INTERRUPT 0x00080000
#define TWE_CONTROL_CLEAR_ATTENTION_INTERRUPT 0x00040000
#define TWE_CONTROL_MASK_COMMAND_INTERRUPT 0x00020000
#define TWE_CONTROL_MASK_RESPONSE_INTERRUPT 0x00010000
#define TWE_CONTROL_UNMASK_COMMAND_INTERRUPT 0x00008000
#define TWE_CONTROL_UNMASK_RESPONSE_INTERRUPT 0x00004000
#define TWE_CONTROL_CLEAR_ERROR_STATUS 0x00000200
#define TWE_CONTROL_ISSUE_SOFT_RESET 0x00000100
#define TWE_CONTROL_ENABLE_INTERRUPTS 0x00000080
#define TWE_CONTROL_DISABLE_INTERRUPTS 0x00000040
#define TWE_CONTROL_ISSUE_HOST_INTERRUPT 0x00000020
#define TWE_CONTROL_CLEAR_PARITY_ERROR 0x00800000
#define TWE_CONTROL_CLEAR_PCI_ABORT 0x00100000
#define TWE_SOFT_RESET(sc) TWE_CONTROL(sc, TWE_CONTROL_ISSUE_SOFT_RESET | \
TWE_CONTROL_CLEAR_HOST_INTERRUPT | \
TWE_CONTROL_CLEAR_ATTENTION_INTERRUPT | \
TWE_CONTROL_MASK_COMMAND_INTERRUPT | \
TWE_CONTROL_MASK_RESPONSE_INTERRUPT | \
TWE_CONTROL_CLEAR_ERROR_STATUS | \
TWE_CONTROL_DISABLE_INTERRUPTS)
/* status register bit definitions */
#define TWE_STATUS_MAJOR_VERSION_MASK 0xF0000000
#define TWE_STATUS_MINOR_VERSION_MASK 0x0F000000
#define TWE_STATUS_PCI_PARITY_ERROR 0x00800000
#define TWE_STATUS_QUEUE_ERROR 0x00400000
#define TWE_STATUS_MICROCONTROLLER_ERROR 0x00200000
#define TWE_STATUS_PCI_ABORT 0x00100000
#define TWE_STATUS_HOST_INTERRUPT 0x00080000
#define TWE_STATUS_ATTENTION_INTERRUPT 0x00040000
#define TWE_STATUS_COMMAND_INTERRUPT 0x00020000
#define TWE_STATUS_RESPONSE_INTERRUPT 0x00010000
#define TWE_STATUS_COMMAND_QUEUE_FULL 0x00008000
#define TWE_STATUS_RESPONSE_QUEUE_EMPTY 0x00004000
#define TWE_STATUS_MICROCONTROLLER_READY 0x00002000
#define TWE_STATUS_COMMAND_QUEUE_EMPTY 0x00001000
#define TWE_STATUS_ALL_INTERRUPTS 0x000F0000
#define TWE_STATUS_CLEARABLE_BITS 0x00D00000
#define TWE_STATUS_EXPECTED_BITS 0x00002000
#define TWE_STATUS_UNEXPECTED_BITS 0x00F80000
/* XXX this is a little harsh, but necessary to chase down firmware problems */
#define TWE_STATUS_PANIC_BITS (TWE_STATUS_MICROCONTROLLER_ERROR)
/* for use with the %b printf format */
#define TWE_STATUS_BITS_DESCRIPTION \
"\20\15CQEMPTY\16UCREADY\17RQEMPTY\20CQFULL\21RINTR\22CINTR\23AINTR\24HINTR\25PCIABRT\26MCERR\27QERR\30PCIPERR\n"
/* detect inconsistencies in the status register */
#define TWE_STATUS_ERRORS(x) \
(((x & TWE_STATUS_PCI_ABORT) || \
(x & TWE_STATUS_PCI_PARITY_ERROR) || \
(x & TWE_STATUS_QUEUE_ERROR) || \
(x & TWE_STATUS_MICROCONTROLLER_ERROR)) && \
(x & TWE_STATUS_MICROCONTROLLER_READY))
/* Response queue bit definitions */
#define TWE_RESPONSE_ID_MASK 0x00000FF0
/* PCI related defines */
#define TWE_IO_CONFIG_REG 0x10
#define TWE_DEVICE_NAME "3ware Storage Controller"
#define TWE_VENDOR_ID 0x13C1
#define TWE_DEVICE_ID 0x1000
#define TWE_DEVICE_ID_ASIC 0x1001
#define TWE_PCI_CLEAR_PARITY_ERROR 0xc100
#define TWE_PCI_CLEAR_PCI_ABORT 0x2000
/* command packet opcodes */
#define TWE_OP_NOP 0x00
#define TWE_OP_INIT_CONNECTION 0x01
#define TWE_OP_READ 0x02
#define TWE_OP_WRITE 0x03
#define TWE_OP_READVERIFY 0x04
#define TWE_OP_VERIFY 0x05
#define TWE_OP_ZEROUNIT 0x08
#define TWE_OP_REPLACEUNIT 0x09
#define TWE_OP_HOTSWAP 0x0a
#define TWE_OP_SETATAFEATURE 0x0c
#define TWE_OP_FLUSH 0x0e
#define TWE_OP_ABORT 0x0f
#define TWE_OP_CHECKSTATUS 0x10
#define TWE_OP_ATA_PASSTHROUGH 0x11
#define TWE_OP_GET_PARAM 0x12
#define TWE_OP_SET_PARAM 0x13
#define TWE_OP_CREATEUNIT 0x14
#define TWE_OP_DELETEUNIT 0x15
#define TWE_OP_REBUILDUNIT 0x17
#define TWE_OP_SECTOR_INFO 0x1a
#define TWE_OP_AEN_LISTEN 0x1c
#define TWE_OP_CMD_PACKET 0x1d
#define TWE_OP_CMD_WITH_DATA 0x1f
/* command status values */
#define TWE_STATUS_RESET 0xff /* controller requests reset */
#define TWE_STATUS_FATAL 0xc0 /* fatal errors not requiring reset */
#define TWE_STATUS_WARNING 0x80 /* warnings */
#define TWE_STAUS_INFO 0x40 /* informative status */
/* misc defines */
#define TWE_ALIGNMENT 0x200
#define TWE_MAX_UNITS 16
#define TWE_COMMAND_ALIGNMENT_MASK 0x1ff
#define TWE_INIT_MESSAGE_CREDITS 0xff /* older firmware has issues with 256 commands */
#define TWE_SHUTDOWN_MESSAGE_CREDITS 0x001
#define TWE_INIT_COMMAND_PACKET_SIZE 0x3
#define TWE_MAX_SGL_LENGTH 62
#define TWE_MAX_ATA_SGL_LENGTH 60
#define TWE_MAX_PASSTHROUGH 4096
#define TWE_Q_LENGTH TWE_INIT_MESSAGE_CREDITS
#define TWE_Q_START 0
#define TWE_MAX_RESET_TRIES 3
#define TWE_BLOCK_SIZE 0x200 /* 512-byte blocks */
#define TWE_SECTOR_SIZE 0x200 /* generic I/O bufffer */
#define TWE_IOCTL 0x80
#define TWE_MAX_AEN_TRIES 100
#define TWE_UNIT_ONLINE 1
/* scatter/gather list entry */
typedef struct
{
u_int32_t address;
u_int32_t length;
} __packed TWE_SG_Entry;
typedef struct {
u_int8_t opcode:5; /* TWE_OP_INITCONNECTION */
u_int8_t res1:3;
u_int8_t size;
u_int8_t request_id;
u_int8_t res2:4;
u_int8_t host_id:4;
u_int8_t status;
u_int8_t flags;
u_int16_t message_credits;
u_int32_t response_queue_pointer;
} __packed TWE_Command_INITCONNECTION;
typedef struct
{
u_int8_t opcode:5; /* TWE_OP_READ/TWE_OP_WRITE */
u_int8_t res1:3;
u_int8_t size;
u_int8_t request_id;
u_int8_t unit:4;
u_int8_t host_id:4;
u_int8_t status;
u_int8_t flags;
u_int16_t block_count;
u_int32_t lba;
TWE_SG_Entry sgl[TWE_MAX_SGL_LENGTH];
} __packed TWE_Command_IO;
typedef struct
{
u_int8_t opcode:5; /* TWE_OP_HOTSWAP */
u_int8_t res1:3;
u_int8_t size;
u_int8_t request_id;
u_int8_t unit:4;
u_int8_t host_id:4;
u_int8_t status;
u_int8_t flags;
u_int8_t action;
#define TWE_OP_HOTSWAP_REMOVE 0x00 /* remove assumed-degraded unit */
#define TWE_OP_HOTSWAP_ADD_CBOD 0x01 /* add CBOD to empty port */
#define TWE_OP_HOTSWAP_ADD_SPARE 0x02 /* add spare to empty port */
u_int8_t aport;
} __packed TWE_Command_HOTSWAP;
typedef struct
{
u_int8_t opcode:5; /* TWE_OP_SETATAFEATURE */
u_int8_t res1:3;
u_int8_t size;
u_int8_t request_id;
u_int8_t unit:4;
u_int8_t host_id:4;
u_int8_t status;
u_int8_t flags;
u_int8_t feature;
#define TWE_OP_SETATAFEATURE_WCE 0x02
#define TWE_OP_SETATAFEATURE_DIS_WCE 0x82
u_int8_t feature_mode;
u_int16_t all_units;
u_int16_t persistence;
} __packed TWE_Command_SETATAFEATURE;
typedef struct
{
u_int8_t opcode:5; /* TWE_OP_CHECKSTATUS */
u_int8_t res1:3;
u_int8_t size;
u_int8_t request_id;
u_int8_t unit:4;
u_int8_t res2:4;
u_int8_t status;
u_int8_t flags;
u_int16_t target_status; /* set low byte to target request's ID */
} __packed TWE_Command_CHECKSTATUS;
typedef struct
{
u_int8_t opcode:5; /* TWE_OP_GETPARAM, TWE_OP_SETPARAM */
u_int8_t res1:3;
u_int8_t size;
u_int8_t request_id;
u_int8_t unit:4;
u_int8_t host_id:4;
u_int8_t status;
u_int8_t flags;
u_int16_t param_count;
TWE_SG_Entry sgl[TWE_MAX_SGL_LENGTH];
} __packed TWE_Command_PARAM;
typedef struct
{
u_int8_t opcode:5; /* TWE_OP_REBUILDUNIT */
u_int8_t res1:3;
u_int8_t size;
u_int8_t request_id;
u_int8_t src_unit:4;
u_int8_t host_id:4;
u_int8_t status;
u_int8_t flags;
u_int8_t action:7;
#define TWE_OP_REBUILDUNIT_NOP 0
#define TWE_OP_REBUILDUNIT_STOP 2 /* stop all rebuilds */
#define TWE_OP_REBUILDUNIT_START 4 /* start rebuild with lowest unit */
#define TWE_OP_REBUILDUNIT_STARTUNIT 5 /* rebuild src_unit (not supported) */
u_int8_t cs:1; /* request state change on src_unit */
u_int8_t logical_subunit; /* for RAID10 rebuild of logical subunit */
} __packed TWE_Command_REBUILDUNIT;
typedef struct
{
u_int8_t opcode:5;
u_int8_t sgl_offset:3;
u_int8_t size;
u_int8_t request_id;
u_int8_t unit:4;
u_int8_t host_id:4;
u_int8_t status;
u_int8_t flags;
u_int16_t param;
u_int16_t features;
u_int16_t sector_count;
u_int16_t sector_num;
u_int16_t cylinder_lo;
u_int16_t cylinder_hi;
u_int8_t drive_head;
u_int8_t command;
TWE_SG_Entry sgl[TWE_MAX_ATA_SGL_LENGTH];
} __packed TWE_Command_ATA;
typedef struct
{
u_int8_t opcode:5;
u_int8_t sgl_offset:3;
u_int8_t size;
u_int8_t request_id;
u_int8_t unit:4;
u_int8_t host_id:4;
u_int8_t status;
u_int8_t flags;
#define TWE_FLAGS_SUCCESS 0x00
#define TWE_FLAGS_INFORMATIONAL 0x01
#define TWE_FLAGS_WARNING 0x02
#define TWE_FLAGS_FATAL 0x03
#define TWE_FLAGS_PERCENTAGE (1<<8) /* bits 0-6 indicate completion percentage */
u_int16_t count; /* block count, parameter count, message credits */
} __packed TWE_Command_Generic;
/* command packet - must be TWE_ALIGNMENT aligned */
typedef union
{
TWE_Command_INITCONNECTION initconnection;
TWE_Command_IO io;
TWE_Command_PARAM param;
TWE_Command_CHECKSTATUS checkstatus;
TWE_Command_REBUILDUNIT rebuildunit;
TWE_Command_SETATAFEATURE setatafeature;
TWE_Command_ATA ata;
TWE_Command_Generic generic;
u_int8_t pad[512];
} TWE_Command;
/* response queue entry */
typedef union
{
struct
{
u_int32_t undefined_1:4;
u_int32_t response_id:8;
u_int32_t undefined_2:20;
} u;
u_int32_t value;
} TWE_Response_Queue;
/*
* From 3ware's documentation:
* All parameters maintained by the controller are grouped into related tables.
* Tables are are accessed indirectly via get and set parameter commands.
* To access a specific parameter in a table, the table ID and parameter index
* are used to uniquely identify a parameter. Table 0xffff is the directory
* table and provides a list of the table IDs and sizes of all other tables.
* Index zero in each table specifies the entire table, and index one specifies
* the size of the table. An entire table can be read or set by using index zero.
*/
#define TWE_PARAM_PARAM_ALL 0
#define TWE_PARAM_PARAM_SIZE 1
#define TWE_PARAM_DIRECTORY 0xffff /* size is 4 * number of tables */
#define TWE_PARAM_DIRECTORY_TABLES 2 /* 16 bits * number of tables */
#define TWE_PARAM_DIRECTORY_SIZES 3 /* 16 bits * number of tables */
#define TWE_PARAM_DRIVESUMMARY 0x0002
#define TWE_PARAM_DRIVESUMMARY_Num 2 /* number of physical drives [2] */
#define TWE_PARAM_DRIVESUMMARY_Status 3 /* array giving drive status per aport */
#define TWE_PARAM_DRIVESTATUS_Missing 0x00
#define TWE_PARAM_DRIVESTATUS_NotSupp 0xfe
#define TWE_PARAM_DRIVESTATUS_Present 0xff
#define TWE_PARAM_UNITSUMMARY 0x0003
#define TWE_PARAM_UNITSUMMARY_Num 2 /* number of logical units [2] */
#define TWE_PARAM_UNITSUMMARY_Status 3 /* array giving unit status [16] */
#define TWE_PARAM_UNITSTATUS_Online (1<<0)
#define TWE_PARAM_UNITSTATUS_Complete (1<<1)
#define TWE_PARAM_UNITSTATUS_MASK 0xfc
#define TWE_PARAM_UNITSTATUS_Normal 0xfc
#define TWE_PARAM_UNITSTATUS_Initialising 0xf4 /* cannot be incomplete */
#define TWE_PARAM_UNITSTATUS_Degraded 0xec
#define TWE_PARAM_UNITSTATUS_Rebuilding 0xdc /* cannot be incomplete */
#define TWE_PARAM_UNITSTATUS_Verifying 0xcc /* cannot be incomplete */
#define TWE_PARAM_UNITSTATUS_Corrupt 0xbc /* cannot be complete */
#define TWE_PARAM_UNITSTATUS_Missing 0x00 /* cannot be complete or online */
#define TWE_PARAM_DRIVEINFO 0x0200 /* add drive number 0x00-0x0f XXX docco confused 0x0100 vs 0x0200 */
#define TWE_PARAM_DRIVEINFO_Size 2 /* size in blocks [4] */
#define TWE_PARAM_DRIVEINFO_Model 3 /* drive model string [40] */
#define TWE_PARAM_DRIVEINFO_Serial 4 /* drive serial number [20] */
#define TWE_PARAM_DRIVEINFO_PhysCylNum 5 /* physical geometry [2] */
#define TWE_PARAM_DRIVEINFO_PhysHeadNum 6 /* [2] */
#define TWE_PARAM_DRIVEINFO_PhysSectorNym 7 /* [2] */
#define TWE_PARAM_DRIVEINFO_LogCylNum 8 /* logical geometry [2] */
#define TWE_PARAM_DRIVEINFO_LogHeadNum 9 /* [2] */
#define TWE_PARAM_DRIVEINFO_LogSectorNum 10 /* [2] */
#define TWE_PARAM_DRIVEINFO_UnitNum 11 /* unit number this drive is associated with or 0xff [1] */
#define TWE_PARAM_DRIVEINFO_DriveFlags 12 /* N/A [1] */
#define TWE_PARAM_APORTTIMEOUT 0x02c0 /* add (aport_number * 3) to parameter index */
#define TWE_PARAM_APORTTIMEOUT_READ 2 /* read timeouts last 24hrs [2] */
#define TWE_PARAM_APORTTIMEOUT_WRITE 3 /* write timeouts last 24hrs [2] */
#define TWE_PARAM_APORTTIMEOUT_DEGRADE 4 /* degrade threshold [2] */
#define TWE_PARAM_UNITINFO 0x0300 /* add unit number 0x00-0x0f */
#define TWE_PARAM_UNITINFO_Number 2 /* unit number [1] */
#define TWE_PARAM_UNITINFO_Status 3 /* unit status [1] */
#define TWE_PARAM_UNITINFO_Capacity 4 /* unit capacity in blocks [4] */
#define TWE_PARAM_UNITINFO_DescriptorSize 5 /* unit descriptor size + 3 bytes [2] */
#define TWE_PARAM_UNITINFO_Descriptor 6 /* unit descriptor, TWE_UnitDescriptor or TWE_Array_Descriptor */
#define TWE_PARAM_UNITINFO_Flags 7 /* unit flags [1] */
#define TWE_PARAM_UNITFLAGS_WCE (1<<0)
#define TWE_PARAM_AEN 0x0401
#define TWE_PARAM_AEN_UnitCode 2 /* (unit number << 8) | AEN code [2] */
#define TWE_AEN_QUEUE_EMPTY 0x00
#define TWE_AEN_SOFT_RESET 0x01
#define TWE_AEN_DEGRADED_MIRROR 0x02 /* reports unit */
#define TWE_AEN_CONTROLLER_ERROR 0x03
#define TWE_AEN_REBUILD_FAIL 0x04 /* reports unit */
#define TWE_AEN_REBUILD_DONE 0x05 /* reports unit */
#define TWE_AEN_INCOMP_UNIT 0x06 /* reports unit */
#define TWE_AEN_INIT_DONE 0x07 /* reports unit */
#define TWE_AEN_UNCLEAN_SHUTDOWN 0x08 /* reports unit */
#define TWE_AEN_APORT_TIMEOUT 0x09 /* reports unit, rate limited to 1 per 2^16 errors */
#define TWE_AEN_DRIVE_ERROR 0x0a /* reports unit */
#define TWE_AEN_REBUILD_STARTED 0x0b /* reports unit */
#define TWE_AEN_QUEUE_FULL 0xff
#define TWE_AEN_TABLE_UNDEFINED 0x15
#define TWE_AEN_CODE(x) ((x) & 0xff)
#define TWE_AEN_UNIT(x) ((x) >> 8)
#define TWE_PARAM_VERSION 0x0402
#define TWE_PARAM_VERSION_Mon 2 /* monitor version [16] */
#define TWE_PARAM_VERSION_FW 3 /* firmware version [16] */
#define TWE_PARAM_VERSION_BIOS 4 /* BIOSs version [16] */
#define TWE_PARAM_VERSION_PCB 5 /* PCB version [8] */
#define TWE_PARAM_VERSION_ATA 6 /* A-chip version [8] */
#define TWE_PARAM_VERSION_PCI 7 /* P-chip version [8] */
#define TWE_PARAM_VERSION_CtrlModel 8 /* N/A */
#define TWE_PARAM_VERSION_CtrlSerial 9 /* N/A */
#define TWE_PARAM_VERSION_SBufSize 10 /* N/A */
#define TWE_PARAM_VERSION_CompCode 11 /* compatibility code [4] */
#define TWE_PARAM_CONTROLLER 0x0403
#define TWE_PARAM_CONTROLLER_DCBSectors 2 /* # sectors reserved for DCB per drive [2] */
#define TWE_PARAM_CONTROLLER_PortCount 3 /* number of drive ports [1] */
#define TWE_PARAM_FEATURES 0x404
#define TWE_PARAM_FEATURES_DriverShutdown 2 /* set to 1 if driver supports shutdown notification [1] */
typedef struct
{
u_int8_t num_subunits; /* must be zero */
u_int8_t configuration;
#define TWE_UD_CONFIG_CBOD 0x0c /* JBOD with DCB, used for mirrors */
#define TWE_UD_CONFIG_SPARE 0x0d /* same as CBOD, but firmware will use as spare */
#define TWE_UD_CONFIG_SUBUNIT 0x0e /* drive is a subunit in an array */
#define TWE_UD_CONFIG_JBOD 0x0f /* plain drive */
u_int8_t phys_drv_num; /* may be 0xff if port can't be determined at runtime */
u_int8_t log_drv_num; /* must be zero for configuration == 0x0f */
u_int32_t start_lba;
u_int32_t block_count; /* actual drive size if configuration == 0x0f, otherwise less DCB size */
} __packed TWE_Unit_Descriptor;
typedef struct
{
u_int8_t flag; /* must be 0xff */
u_int8_t res1;
u_int8_t mirunit_status[4]; /* bitmap of functional subunits in each mirror */
u_int8_t res2[6];
} __packed TWE_Mirror_Descriptor;
typedef struct
{
u_int8_t num_subunits; /* number of subunits, or number of mirror units in RAID10 */
u_int8_t configuration;
#define TWE_UD_CONFIG_RAID0 0x00
#define TWE_UD_CONFIG_RAID1 0x01
#define TWE_UD_CONFIG_TwinStor 0x02
#define TWE_UD_CONFIG_RAID5 0x05
#define TWE_UD_CONFIG_RAID10 0x06
u_int8_t stripe_size;
#define TWE_UD_STRIPE_4k 0x03
#define TWE_UD_STRIPE_8k 0x04
#define TWE_UD_STRIPE_16k 0x05
#define TWE_UD_STRIPE_32k 0x06
#define TWE_UD_STRIPE_64k 0x07
u_int8_t log_drv_status; /* bitmap of functional subunits, or mirror units in RAID10 */
u_int32_t start_lba;
u_int32_t block_count; /* actual drive size if configuration == 0x0f, otherwise less DCB size */
TWE_Unit_Descriptor subunit[0]; /* subunit descriptors, in RAID10 mode is [mirunit][subunit] */
} __packed TWE_Array_Descriptor;
typedef struct
{
u_int16_t table_id;
u_int8_t parameter_id;
u_int8_t parameter_size_bytes;
u_int8_t data[0];
} __packed TWE_Param;