mscp.h

早期freebsd实现

	long	sccc_errlgfl;	/* ? */
	short	sccc_xxx2;	/* ? */
	short	sccc_copyspd;	/* ? */
};

/*
 * Set Controller Characteristics end variant
 */
struct mscpv_scce {
	u_short	scce_version;		/* MSCP version number */
	u_short	scce_ctlrflags;		/* controller flags */
	u_short	scce_ctlrtimo;		/* controller timeout */
	u_short	scce_ctlrcmdl;		/* ??? */
	quad	scce_ctlrid;		/* controller ID */
	long	scce_xxx[3];	/* ? */
	long	scce_volser;		/* volume serial number */
};

/*
 * On Line command variant
 */
struct mscpv_onlc {
	long	onlc_xxx1[4];	/* ? */
	long	onlc_errlgfl;		/* error log flag? */
	short	onlc_xxx2;	/* ? */
	short	onlc_copyspd;		/* copy speed? */
};

/*
 * On Line end variant
 */
struct mscpv_onle {
	long	onle_xxx1[3];	/* ? */
/*???*/	short	onle_xxx2;	/* ? */
	u_char	onle_drivetype;		/* drive type index (same in guse) */
	char	onle_xxx3;	/* ? */
	long	onle_mediaid;		/* media type id (same in guse) */
	long	onle_xxx4;	/* ? */
	long	onle_unitsize;		/* unit size in sectors */
	long	onle_volser;		/* volume serial number */
};

/*
 * Get Unit Status end variant (and Avail Attn?)
 */
struct mscpv_guse {
	u_short	guse_multunit;		/* multi-unit code */
	u_short	guse_unitflags;		/* unit flags */
	long	guse_hostid;		/* host id */
	long	guse_unitid0;	/*???*/
	short	guse_unitid1;	/*???*/
	u_char	guse_drivetype;		/* drive type index */
	u_char	guse_unitid2;	/*???*/
	long	guse_mediaid;		/* media type id (encoded) */
	short	guse_shadowunit;	/* shadow unit */
	short	guse_shadowstat;	/* shadow status */
	u_short	guse_nspt;		/* sectors per track */
	u_short	guse_group;		/* track group size */
	u_short	guse_ngpc;		/* groups per cylinder */
	u_short	guse_xxx;		/* reserved */
	u_short	guse_rctsize;		/* RCT size (sectors) */
	u_char	guse_nrpt;		/* RBNs per track */
	u_char	guse_nrct;		/* number of RCTs */
};

/*
 * Macros to break up and build media IDs.  An ID encodes the port
 * type in the top 10 bits, and the drive type in the remaining 22.
 * The 10 bits, and 15 of the 22, are in groups of 5, with the value
 * 0 representing space and values 1..26 representing A..Z.  The low
 * 7 bits represent a number in 0..127.  Hence an RA81 on a UDA50
 * is <D><U><R><A>< >81, or 0x25641051.  This encoding scheme is known
 * in part in uda.c.
 *
 * The casts below are just to make pcc generate better code.
 */
#define	MSCP_MEDIA_PORT(id)	(((long)(id) >> 22) & 0x3ff)	/* port */
#define	MSCP_MEDIA_DRIVE(id)	((long)(id) & 0x003fffff)	/* drive */
#define	MSCP_MID_ECH(n, id)	(((long)(id) >> ((n) * 5 + 7)) & 0x1f)
#define	MSCP_MID_CHAR(n, id) \
	(MSCP_MID_ECH(n, id) ? MSCP_MID_ECH(n, id) + '@' : ' ')
#define	MSCP_MID_NUM(id)	((id) & 0x7f)
/* for, e.g., RA81 */
#define	MSCP_MKDRIVE2(a, b, n) \
	(((a) - '@') << 17 | ((b) - '@') << 12 | (n))
/* for, e.g., RRD50 */
#define	MSCP_MKDRIVE3(a, b, c, n) \
	(((a) - '@') << 17 | ((b) - '@') << 12 | ((c) - '@') << 7 | (n))

/*
 * Error datagram variant.
 */
struct mscpv_erd {
	quad	erd_ctlrid;		/* controller ID */
	u_char	erd_ctlrsoftware;	/* controller software version */
	u_char	erd_ctlrhardware;	/* controller hardware version */
	u_short	erd_multiunit;		/* multi-unit code (?) */
	union {
		u_long	un_busaddr;	/* bus address, if mem access err */
		quad	un_unitid;	/* unit id, otherwise */
	} erd_un1;
#define	erd_busaddr	erd_un1.un_busaddr
#define	erd_unitid	erd_un1.un_unitid
	u_char	erd_unitsoftware;	/* unit software version */
	u_char	erd_unithardware;	/* unit hardware version */
	union {
		u_char	un_b[2];	/* level, retry (if disk xfer err) */
		u_short	un_s;		/* cylinder (if small disk error) */
	} erd_un2;
#define	erd_level	erd_un2.un_b[0]
#define	erd_retry	erd_un2.un_b[1]
#define	erd_sdecyl	erd_un2.un_s
	long	erd_volser;		/* volume serial number */
	u_long	erd_hdr;		/* `header' (block number) */
	u_char	erd_sdistat[12];	/* SDI status information (?) */
};

/*
 * I am making brash assumptions about the first four bytes of all
 * MSCP packets.  These appear to be true for both UDA50s and TMSCP
 * devices (TU81, TA81, TK50).  DEC claim that these four bytes are
 * not part of MSCP itself, yet at least the length is necessary
 * for, e.g., error checking.
 */
struct mscp {
	u_short	mscp_msglen;		/* length in bytes */
	u_char	mscp_msgtc;		/* type (high 4 bits) and credits */
	u_char	mscp_vcid;		/* virtual circuit ID */
	long	mscp_cmdref;		/* command reference number */
	u_short	mscp_unit;		/* unit number */
	u_short	mscp_seqnum;		/* sequence number */
	u_char	mscp_opcode;		/* opcode */
#define	mscp_format	mscp_opcode	/* aka format (datagrams) */
	u_char	mscp_flags;		/* flags */
	u_short	mscp_modifier;		/* modifier (commands) */
#define	mscp_status	mscp_modifier	/* aka status (ends) */
#define	mscp_event	mscp_modifier	/* aka event (datagrams) */
	union {
		struct	mscpv_seq un_seq;	/* generic sequential msg */
		struct	mscpv_sccc un_sccc;	/* SCC command */
		struct	mscpv_scce un_scce;	/* SCC end */
		struct	mscpv_onlc un_onlc;	/* on line command */
		struct	mscpv_onle un_onle;	/* on line end */
		struct	mscpv_guse un_guse;	/* get unit status */
		struct	mscpv_erd un_erd;	/* error datagram */
	} mscp_un;
/*???*/	long	mscp_xxx;		/* pad to 64 bytes */
};

/*
 * Define message length according to the DEC specifications by dropping
 * the four byte header.
 */
#define	MSCP_MSGLEN	(sizeof (struct mscp) - 4)

/*
 * Shorthand
 */

/*
 * Generic packet
 */
#define	mscp_seq	mscp_un.un_seq

/*
 * Set Controller Characteristics packet
 */
#define	mscp_sccc	mscp_un.un_sccc

/*
 * Set Controller Characteristics end packet
 */
#define	mscp_scce	mscp_un.un_scce

/*
 * Online / Set Unit Characteristics command packet
 */
#define	mscp_onlc	mscp_un.un_onlc

/*
 * Online end packet
 */
#define	mscp_onle	mscp_un.un_onle

/*
 * Get Unit Status end packet
 */
#define	mscp_guse	mscp_un.un_guse

/*
 * MSCP Error Log packet
 */
#define	mscp_erd	mscp_un.un_erd

/*
 * MSCP seq_addr field actually belongs to overall packet.
 */
#define	mscp_addr	mscp_seq.seq_addr

/*
 * Macros to break up mscp_msgtc, and types.
 */
#define	MSCP_MSGTYPE(m)	((m) & 0xf0)
#define	MSCP_CREDITS(m)	((m) & 0x0f)

#define	MSCPT_SEQ		0x00	/* sequential message */
#define	MSCPT_DATAGRAM		0x10	/* error datagram */
#define	MSCPT_CREDITS		0x20	/* credit notification */
#define	MSCPT_MAINTENANCE	0xf0	/* who knows */


/*
 * Here begin more perhaps brash assumptions about MSCP devices...
 */

/*
 * MSCP controllers have `command rings' and `response rings'.  A
 * command ring is a pool of MSCP packets that the host uses to give
 * commands to the controller; a response ring is a pool of MSCP
 * packets that the controller uses to give back responses.  Entries
 * in the command and response rings are `owned' by either the host
 * or the controller; only the owner is allowed to alter any of the
 * fields in the MSCP packet.  Thus, free command packets are owned
 * by the host, and free response packets by the controller.  When
 * the host gives a packet to the controller, it tells the controller
 * by touching a device register; when the controller gives a response
 * to the host, it generates an interrupt if enabled, and sets
 * a device register as well.
 *
 * The pool is `described' by a set of pointers to the packets, along
 * with the two flags below.
 */
#define	MSCP_OWN	0x80000000	/* controller owns this packet */
#define	MSCP_INT	0x40000000	/* controller should interrupt */