scsi.h

GNU Mach 微内核源代码, 基于美国卡内基美隆大学的 Mach 研究项目

/*
 *  scsi.h Copyright (C) 1992 Drew Eckhardt 
 *         Copyright (C) 1993, 1994, 1995 Eric Youngdale
 *  generic SCSI package header file by
 *      Initial versions: Drew Eckhardt
 *      Subsequent revisions: Eric Youngdale
 *
 *  <[e-mail]>
 *
 *       Modified by Eric Youngdale [e-mail] to
 *       add scatter-gather, multiple outstanding request, and other
 *       enhancements.
 */

#ifndef _SCSI_H
#define _SCSI_H

/*
 * Some of the public constants are being moved to this file.
 * We include it here so that what came from where is transparent.
 */
#include <scsi/scsi.h>

#include <linux/random.h>


/*
 * Some defs, in case these are not defined elsewhere.
 */
#ifndef TRUE
# define TRUE 1
#endif
#ifndef FALSE
# define FALSE 0
#endif


extern void scsi_make_blocked_list(void);
extern volatile int in_scan_scsis;
extern const unsigned char scsi_command_size[8];
#define COMMAND_SIZE(opcode) scsi_command_size[((opcode) >> 5) & 7]
#define IDENTIFY_BASE       0x80
#define IDENTIFY(can_disconnect, lun)   (IDENTIFY_BASE |\
		     ((can_disconnect) ?  0x40 : 0) |\
		     ((lun) & 0x07)) 
#define MAX_SCSI_DEVICE_CODE 10
extern const char *const scsi_device_types[MAX_SCSI_DEVICE_CODE];

		 
    
/*
 *  the return of the status word will be in the following format :
 *  The low byte is the status returned by the SCSI command, 
 *  with vendor specific bits masked.
 *  
 *  The next byte is the message which followed the SCSI status.
 *  This allows a stos to be used, since the Intel is a little
 *  endian machine.
 *  
 *  The final byte is a host return code, which is one of the following.
 *  
 *  IE 
 *  lsb     msb
 *  status  msg host code   
 *  
 *  Our errors returned by OUR driver, NOT SCSI message.  Or'd with
 *  SCSI message passed back to driver <IF any>.
 */


#define DID_OK          0x00 /* NO error                                */
#define DID_NO_CONNECT  0x01 /* Couldn't connect before timeout period  */
#define DID_BUS_BUSY    0x02 /* BUS stayed busy through time out period */
#define DID_TIME_OUT    0x03 /* TIMED OUT for other reason              */
#define DID_BAD_TARGET  0x04 /* BAD target.                             */
#define DID_ABORT       0x05 /* Told to abort for some other reason     */
#define DID_PARITY      0x06 /* Parity error                            */
#define DID_ERROR       0x07 /* Internal error                          */
#define DID_RESET       0x08 /* Reset by somebody.                      */
#define DID_BAD_INTR    0x09 /* Got an interrupt we weren't expecting.  */ 
#define DRIVER_OK       0x00 /* Driver status                           */ 

/*
 *  These indicate the error that occurred, and what is available.
 */

#define DRIVER_BUSY         0x01
#define DRIVER_SOFT         0x02
#define DRIVER_MEDIA        0x03
#define DRIVER_ERROR        0x04    

#define DRIVER_INVALID      0x05
#define DRIVER_TIMEOUT      0x06
#define DRIVER_HARD         0x07
#define DRIVER_SENSE	    0x08

#define SUGGEST_RETRY       0x10
#define SUGGEST_ABORT       0x20 
#define SUGGEST_REMAP       0x30
#define SUGGEST_DIE         0x40
#define SUGGEST_SENSE       0x80
#define SUGGEST_IS_OK       0xff

#define DRIVER_MASK         0x0f
#define SUGGEST_MASK        0xf0

#define MAX_COMMAND_SIZE    12

/*
 *  SCSI command sets
 */

#define SCSI_UNKNOWN    0
#define SCSI_1          1
#define SCSI_1_CCS      2
#define SCSI_2          3

/*
 *  Every SCSI command starts with a one byte OP-code.
 *  The next byte's high three bits are the LUN of the
 *  device.  Any multi-byte quantities are stored high byte
 *  first, and may have a 5 bit MSB in the same byte
 *  as the LUN.
 */

/*
 *      Manufacturers list
 */

#define SCSI_MAN_UNKNOWN     0
#define SCSI_MAN_NEC         1
#define SCSI_MAN_TOSHIBA     2
#define SCSI_MAN_NEC_OLDCDR  3
#define SCSI_MAN_SONY        4
#define SCSI_MAN_PIONEER     5

/*
 *  As the scsi do command functions are intelligent, and may need to
 *  redo a command, we need to keep track of the last command
 *  executed on each one.
 */

#define WAS_RESET       0x01
#define WAS_TIMEDOUT    0x02
#define WAS_SENSE       0x04
#define IS_RESETTING    0x08
#define IS_ABORTING     0x10
#define ASKED_FOR_SENSE 0x20

/*
 *  The scsi_device struct contains what we know about each given scsi
 *  device.
 */

typedef struct scsi_device {
    struct scsi_device * next;      /* Used for linked list */

    unsigned char id, lun, channel;

    unsigned int manufacturer;      /* Manufacturer of device, for using 
				     * vendor-specific cmd's */
    int attached;                   /* # of high level drivers attached to 
				     * this */
    int access_count;               /* Count of open channels/mounts */
    struct wait_queue * device_wait;/* Used to wait if device is busy */
    struct Scsi_Host * host;
    void (*scsi_request_fn)(void);  /* Used to jumpstart things after an 
				     * ioctl */
    struct scsi_cmnd *device_queue; /* queue of SCSI Command structures */
    void *hostdata;                 /* available to low-level driver */
    char type;
    char scsi_level;
    char vendor[8], model[16], rev[4];
    unsigned char current_tag;      /* current tag */
    unsigned char sync_min_period;  /* Not less than this period */
    unsigned char sync_max_offset;  /* Not greater than this offset */
    unsigned char queue_depth;	    /* How deep a queue to use */

    unsigned writeable:1;
    unsigned removable:1; 
    unsigned random:1;
    unsigned has_cmdblocks:1;
    unsigned changed:1;             /* Data invalid due to media change */
    unsigned busy:1;                /* Used to prevent races */
    unsigned lockable:1;            /* Able to prevent media removal */
    unsigned borken:1;              /* Tell the Seagate driver to be 
				     * painfully slow on this device */ 
    unsigned tagged_supported:1;    /* Supports SCSI-II tagged queuing */
    unsigned tagged_queue:1;        /* SCSI-II tagged queuing enabled */
    unsigned disconnect:1;          /* can disconnect */
    unsigned soft_reset:1;          /* Uses soft reset option */
    unsigned sync:1;                /* Negotiate for sync transfers */
    unsigned single_lun:1;          /* Indicates we should only allow I/O to
                                     * one of the luns for the device at a 
                                     * time. */
    unsigned was_reset:1;           /* There was a bus reset on the bus for 
                                     * this device */
    unsigned expecting_cc_ua:1;     /* Expecting a CHECK_CONDITION/UNIT_ATTN
                                     * because we did a bus reset. */
} Scsi_Device;

/*
 *  Use these to separate status msg and our bytes
 */

#define status_byte(result) (((result) >> 1) & 0x1f)
#define msg_byte(result)    (((result) >> 8) & 0xff)
#define host_byte(result)   (((result) >> 16) & 0xff)
#define driver_byte(result) (((result) >> 24) & 0xff)
#define suggestion(result)  (driver_byte(result) & SUGGEST_MASK)

#define sense_class(sense)  (((sense) >> 4) & 0x7)
#define sense_error(sense)  ((sense) & 0xf)
#define sense_valid(sense)  ((sense) & 0x80);

/*
 *  These are the SCSI devices available on the system.
 */

extern Scsi_Device * scsi_devices;

extern struct hd_struct * sd;

#if defined(MAJOR_NR) && (MAJOR_NR == SCSI_DISK_MAJOR)
extern struct hd_struct * sd;
#endif

/*
 *  Initializes all SCSI devices.  This scans all scsi busses.
 */ 

extern int scsi_dev_init (void);

struct scatterlist {
    char *  address;    /* Location data is to be transferred to */
    char * alt_address; /* Location of actual if address is a 
			 * dma indirect buffer.  NULL otherwise */
    unsigned int length;
};

#ifdef __alpha__
# define ISA_DMA_THRESHOLD (~0UL)
#else
# define ISA_DMA_THRESHOLD (0x00ffffff)
#endif
#define CONTIGUOUS_BUFFERS(X,Y) ((X->b_data+X->b_size) == Y->b_data)


/*
 * These are the return codes for the abort and reset functions.  The mid-level
 * code uses these to decide what to do next.  Each of the low level abort
 * and reset functions must correctly indicate what it has done.
 * The descriptions are written from the point of view of the mid-level code,
 * so that the return code is telling the mid-level drivers exactly what
 * the low level driver has already done, and what remains to be done.
 */

/* We did not do anything.  
 * Wait some more for this command to complete, and if this does not work, 
 * try something more serious. */ 
#define SCSI_ABORT_SNOOZE 0

/* This means that we were able to abort the command.  We have already
 * called the mid-level done function, and do not expect an interrupt that 
 * will lead to another call to the mid-level done function for this command */
#define SCSI_ABORT_SUCCESS 1

/* We called for an abort of this command, and we should get an interrupt 
 * when this succeeds.  Thus we should not restore the timer for this
 * command in the mid-level abort function. */
#define SCSI_ABORT_PENDING 2

/* Unable to abort - command is currently on the bus.  Grin and bear it. */
#define SCSI_ABORT_BUSY 3

/* The command is not active in the low level code. Command probably
 * finished. */
#define SCSI_ABORT_NOT_RUNNING 4

/* Something went wrong.  The low level driver will indicate the correct
 * error condition when it calls scsi_done, so the mid-level abort function
 * can simply wait until this comes through */
#define SCSI_ABORT_ERROR 5

/* We do not know how to reset the bus, or we do not want to.  Bummer.
 * Anyway, just wait a little more for the command in question, and hope that
 * it eventually finishes.  If it never finishes, the SCSI device could
 * hang, so use this with caution. */
#define SCSI_RESET_SNOOZE 0

/* We do not know how to reset the bus, or we do not want to.  Bummer.
 * We have given up on this ever completing.  The mid-level code will
 * request sense information to decide how to proceed from here. */
#define SCSI_RESET_PUNT 1

/* This means that we were able to reset the bus.  We have restarted all of
 * the commands that should be restarted, and we should be able to continue
 * on normally from here.  We do not expect any interrupts that will return
 * DID_RESET to any of the other commands in the host_queue, and the mid-level
 * code does not need to do anything special to keep the commands alive. 
 * If a hard reset was performed then all outstanding commands on the
 * bus have been restarted. */
#define SCSI_RESET_SUCCESS 2

/* We called for a reset of this bus, and we should get an interrupt 
 * when this succeeds.  Each command should get its own status
 * passed up to scsi_done, but this has not happened yet. 
 * If a hard reset was performed, then we expect an interrupt
 * for *each* of the outstanding commands that will have the
 * effect of restarting the commands.
 */
#define SCSI_RESET_PENDING 3

/* We did a reset, but do not expect an interrupt to signal DID_RESET.
 * This tells the upper level code to request the sense info, and this
 * should keep the command alive. */
#define SCSI_RESET_WAKEUP 4

/* The command is not active in the low level code. Command probably
   finished. */
#define SCSI_RESET_NOT_RUNNING 5

/* Something went wrong, and we do not know how to fix it. */
#define SCSI_RESET_ERROR 6

#define SCSI_RESET_SYNCHRONOUS		0x01