drivers/scsi/scsi.h

   1 /*
   2  *  scsi.h Copyright (C) 1992 Drew Eckhardt
   3  *         Copyright (C) 1993, 1994, 1995 Eric Youngdale
   4  *  generic SCSI package header file by
   5  *      Initial versions: Drew Eckhardt
   6  *      Subsequent revisions: Eric Youngdale
   7  *
   8  *  <drew@colorado.edu>
   9  *
  10  *       Modified by Eric Youngdale eric@aib.com to
  11  *       add scatter-gather, multiple outstanding request, and other
  12  *       enhancements.
  13  */
  14
  15 #ifndef _SCSI_H
  16 #define _SCSI_H
  17
  18 #include <linux/config.h>       /* for CONFIG_SCSI_LOGGING */
  19
  20 /*
  21  * Some of the public constants are being moved to this file.
  22  * We include it here so that what came from where is transparent.
  23  */
  24 #include <scsi/scsi.h>
  25
  26 #include <linux/random.h>
  27
  28 #include <asm/hardirq.h>
  29 #include <asm/scatterlist.h>
  30 #include <asm/io.h>
  31
  32 /*
  33  * Some defs, in case these are not defined elsewhere.
  34  */
  35 #ifndef TRUE
  36 #define TRUE 1
  37 #endif
  38 #ifndef FALSE
  39 #define FALSE 0
  40 #endif
  41
  42 #define MAX_SCSI_DEVICE_CODE 14
  43 extern const char *const scsi_device_types[MAX_SCSI_DEVICE_CODE];
  44
  45 #ifdef DEBUG
  46 #define SCSI_TIMEOUT (5*HZ)
  47 #else
  48 #define SCSI_TIMEOUT (2*HZ)
  49 #endif
  50
  51 /*
  52  *  Use these to separate status msg and our bytes
  53  *
  54  *  These are set by:
  55  *
  56  *      status byte = set from target device
  57  *      msg_byte    = return status from host adapter itself.
  58  *      host_byte   = set by low-level driver to indicate status.
  59  *      driver_byte = set by mid-level.
  60  */
  61 #define status_byte(result) (((result) >> 1) & 0x1f)
  62 #define msg_byte(result)    (((result) >> 8) & 0xff)
  63 #define host_byte(result)   (((result) >> 16) & 0xff)
  64 #define driver_byte(result) (((result) >> 24) & 0xff)
  65 #define suggestion(result)  (driver_byte(result) & SUGGEST_MASK)
  66
  67 #define sense_class(sense)  (((sense) >> 4) & 0x7)
  68 #define sense_error(sense)  ((sense) & 0xf)
  69 #define sense_valid(sense)  ((sense) & 0x80);
  70
  71 #define NEEDS_RETRY     0x2001
  72 #define SUCCESS         0x2002
  73 #define FAILED          0x2003
  74 #define QUEUED          0x2004
  75 #define SOFT_ERROR      0x2005
  76 #define ADD_TO_MLQUEUE  0x2006
  77
  78 /*
  79  * These are the values that scsi_cmd->state can take.
  80  */
  81 #define SCSI_STATE_TIMEOUT         0x1000
  82 #define SCSI_STATE_FINISHED        0x1001
  83 #define SCSI_STATE_FAILED          0x1002
  84 #define SCSI_STATE_QUEUED          0x1003
  85 #define SCSI_STATE_UNUSED          0x1006
  86 #define SCSI_STATE_DISCONNECTING   0x1008
  87 #define SCSI_STATE_INITIALIZING    0x1009
  88 #define SCSI_STATE_BHQUEUE         0x100a
  89 #define SCSI_STATE_MLQUEUE         0x100b
  90
  91 /*
  92  * These are the values that the owner field can take.
  93  * They are used as an indication of who the command belongs to.
  94  */
  95 #define SCSI_OWNER_HIGHLEVEL      0x100
  96 #define SCSI_OWNER_MIDLEVEL       0x101
  97 #define SCSI_OWNER_LOWLEVEL       0x102
  98 #define SCSI_OWNER_ERROR_HANDLER  0x103
  99 #define SCSI_OWNER_BH_HANDLER     0x104
 100 #define SCSI_OWNER_NOBODY         0x105
 101
 102 #define COMMAND_SIZE(opcode) scsi_command_size[((opcode) >> 5) & 7]
 103
 104 #define IDENTIFY_BASE       0x80
 105 #define IDENTIFY(can_disconnect, lun)   (IDENTIFY_BASE |\
 106                      ((can_disconnect) ?  0x40 : 0) |\
 107                      ((lun) & 0x07))
 108
 109
 110 /*
 111  * This defines the scsi logging feature.  It is a means by which the
 112  * user can select how much information they get about various goings on,
 113  * and it can be really useful for fault tracing.  The logging word is divided
 114  * into 8 nibbles, each of which describes a loglevel.  The division of things
 115  * is somewhat arbitrary, and the division of the word could be changed if it
 116  * were really needed for any reason.  The numbers below are the only place where these
 117  * are specified.  For a first go-around, 3 bits is more than enough, since this
 118  * gives 8 levels of logging (really 7, since 0 is always off).  Cutting to 2 bits
 119  * might be wise at some point.
 120  */
 121
 122 #define SCSI_LOG_ERROR_SHIFT              0
 123 #define SCSI_LOG_TIMEOUT_SHIFT            3
 124 #define SCSI_LOG_SCAN_SHIFT               6
 125 #define SCSI_LOG_MLQUEUE_SHIFT            9
 126 #define SCSI_LOG_MLCOMPLETE_SHIFT         12
 127 #define SCSI_LOG_LLQUEUE_SHIFT            15
 128 #define SCSI_LOG_LLCOMPLETE_SHIFT         18
 129 #define SCSI_LOG_HLQUEUE_SHIFT            21
 130 #define SCSI_LOG_HLCOMPLETE_SHIFT         24
 131 #define SCSI_LOG_IOCTL_SHIFT              27
 132
 133 #define SCSI_LOG_ERROR_BITS               3
 134 #define SCSI_LOG_TIMEOUT_BITS             3
 135 #define SCSI_LOG_SCAN_BITS                3
 136 #define SCSI_LOG_MLQUEUE_BITS             3
 137 #define SCSI_LOG_MLCOMPLETE_BITS          3
 138 #define SCSI_LOG_LLQUEUE_BITS             3
 139 #define SCSI_LOG_LLCOMPLETE_BITS          3
 140 #define SCSI_LOG_HLQUEUE_BITS             3
 141 #define SCSI_LOG_HLCOMPLETE_BITS          3
 142 #define SCSI_LOG_IOCTL_BITS               3
 143
 144 #if CONFIG_SCSI_LOGGING
 145
 146 #define SCSI_CHECK_LOGGING(SHIFT, BITS, LEVEL, CMD)     \
 147 {                                                       \
 148         unsigned int mask;                              \
 149                                                         \
 150         mask = (1 << (BITS)) - 1;                       \
 151         if( ((scsi_logging_level >> (SHIFT)) & mask) > (LEVEL) ) \
 152         {                                               \
 153                 (CMD);                                  \
 154         }                                               \
 155 }
 156
 157 #define SCSI_SET_LOGGING(SHIFT, BITS, LEVEL)            \
 158 {                                                       \
 159         unsigned int mask;                              \
 160                                                         \
 161         mask = ((1 << (BITS)) - 1) << SHIFT;            \
 162         scsi_logging_level = ((scsi_logging_level & ~mask) \
 163                               | ((LEVEL << SHIFT) & mask));     \
 164 }
 165
 166
 167
 168 #else
 169
 170 /*
 171  * With no logging enabled, stub these out so they don't do anything.
 172  */
 173 #define SCSI_SET_LOGGING(SHIFT, BITS, LEVEL)
 174
 175 #define SCSI_CHECK_LOGGING(SHIFT, BITS, LEVEL, CMD)
 176 #endif
 177
 178 /*
 179  * These are the macros that are actually used throughout the code to
 180  * log events.  If logging isn't enabled, they are no-ops and will be
 181  * completely absent from the user's code.
 182  *
 183  * The 'set' versions of the macros are really intended to only be called
 184  * from the /proc filesystem, and in production kernels this will be about
 185  * all that is ever used.  It could be useful in a debugging environment to
 186  * bump the logging level when certain strange events are detected, however.
 187  */
 188 #define SCSI_LOG_ERROR_RECOVERY(LEVEL,CMD)  \
 189         SCSI_CHECK_LOGGING(SCSI_LOG_ERROR_SHIFT, SCSI_LOG_ERROR_BITS, LEVEL,CMD);
 190 #define SCSI_LOG_TIMEOUT(LEVEL,CMD)  \
 191         SCSI_CHECK_LOGGING(SCSI_LOG_TIMEOUT_SHIFT, SCSI_LOG_TIMEOUT_BITS, LEVEL,CMD);
 192 #define SCSI_LOG_SCAN_BUS(LEVEL,CMD)  \
 193         SCSI_CHECK_LOGGING(SCSI_LOG_SCAN_SHIFT, SCSI_LOG_SCAN_BITS, LEVEL,CMD);
 194 #define SCSI_LOG_MLQUEUE(LEVEL,CMD)  \
 195         SCSI_CHECK_LOGGING(SCSI_LOG_MLQUEUE_SHIFT, SCSI_LOG_MLQUEUE_BITS, LEVEL,CMD);
 196 #define SCSI_LOG_MLCOMPLETE(LEVEL,CMD)  \
 197         SCSI_CHECK_LOGGING(SCSI_LOG_MLCOMPLETE_SHIFT, SCSI_LOG_MLCOMPLETE_BITS, LEVEL,CMD);
 198 #define SCSI_LOG_LLQUEUE(LEVEL,CMD)  \
 199         SCSI_CHECK_LOGGING(SCSI_LOG_LLQUEUE_SHIFT, SCSI_LOG_LLQUEUE_BITS, LEVEL,CMD);
 200 #define SCSI_LOG_LLCOMPLETE(LEVEL,CMD)  \
 201         SCSI_CHECK_LOGGING(SCSI_LOG_LLCOMPLETE_SHIFT, SCSI_LOG_LLCOMPLETE_BITS, LEVEL,CMD);
 202 #define SCSI_LOG_HLQUEUE(LEVEL,CMD)  \
 203         SCSI_CHECK_LOGGING(SCSI_LOG_HLQUEUE_SHIFT, SCSI_LOG_HLQUEUE_BITS, LEVEL,CMD);
 204 #define SCSI_LOG_HLCOMPLETE(LEVEL,CMD)  \
 205         SCSI_CHECK_LOGGING(SCSI_LOG_HLCOMPLETE_SHIFT, SCSI_LOG_HLCOMPLETE_BITS, LEVEL,CMD);
 206 #define SCSI_LOG_IOCTL(LEVEL,CMD)  \
 207         SCSI_CHECK_LOGGING(SCSI_LOG_IOCTL_SHIFT, SCSI_LOG_IOCTL_BITS, LEVEL,CMD);
 208
 209
 210 #define SCSI_SET_ERROR_RECOVERY_LOGGING(LEVEL)  \
 211         SCSI_SET_LOGGING(SCSI_LOG_ERROR_SHIFT, SCSI_LOG_ERROR_BITS, LEVEL);
 212 #define SCSI_SET_TIMEOUT_LOGGING(LEVEL)  \
 213         SCSI_SET_LOGGING(SCSI_LOG_TIMEOUT_SHIFT, SCSI_LOG_TIMEOUT_BITS, LEVEL);
 214 #define SCSI_SET_SCAN_BUS_LOGGING(LEVEL)  \
 215         SCSI_SET_LOGGING(SCSI_LOG_SCAN_SHIFT, SCSI_LOG_SCAN_BITS, LEVEL);
 216 #define SCSI_SET_MLQUEUE_LOGGING(LEVEL)  \
 217         SCSI_SET_LOGGING(SCSI_LOG_MLQUEUE_SHIFT, SCSI_LOG_MLQUEUE_BITS, LEVEL);
 218 #define SCSI_SET_MLCOMPLETE_LOGGING(LEVEL)  \
 219         SCSI_SET_LOGGING(SCSI_LOG_MLCOMPLETE_SHIFT, SCSI_LOG_MLCOMPLETE_BITS, LEVEL);
 220 #define SCSI_SET_LLQUEUE_LOGGING(LEVEL)  \
 221         SCSI_SET_LOGGING(SCSI_LOG_LLQUEUE_SHIFT, SCSI_LOG_LLQUEUE_BITS, LEVEL);
 222 #define SCSI_SET_LLCOMPLETE_LOGGING(LEVEL)  \
 223         SCSI_SET_LOGGING(SCSI_LOG_LLCOMPLETE_SHIFT, SCSI_LOG_LLCOMPLETE_BITS, LEVEL);
 224 #define SCSI_SET_HLQUEUE_LOGGING(LEVEL)  \
 225         SCSI_SET_LOGGING(SCSI_LOG_HLQUEUE_SHIFT, SCSI_LOG_HLQUEUE_BITS, LEVEL);
 226 #define SCSI_SET_HLCOMPLETE_LOGGING(LEVEL)  \
 227         SCSI_SET_LOGGING(SCSI_LOG_HLCOMPLETE_SHIFT, SCSI_LOG_HLCOMPLETE_BITS, LEVEL);
 228 #define SCSI_SET_IOCTL_LOGGING(LEVEL)  \
 229         SCSI_SET_LOGGING(SCSI_LOG_IOCTL_SHIFT, SCSI_LOG_IOCTL_BITS, LEVEL);
 230
 231 /*
 232  *  the return of the status word will be in the following format :
 233  *  The low byte is the status returned by the SCSI command,
 234  *  with vendor specific bits masked.
 235  *
 236  *  The next byte is the message which followed the SCSI status.
 237  *  This allows a stos to be used, since the Intel is a little
 238  *  endian machine.
 239  *
 240  *  The final byte is a host return code, which is one of the following.
 241  *
 242  *  IE
 243  *  lsb     msb
 244  *  status  msg host code
 245  *
 246  *  Our errors returned by OUR driver, NOT SCSI message.  Or'd with
 247  *  SCSI message passed back to driver <IF any>.
 248  */
 249
 250
 251 #define DID_OK          0x00    /* NO error                                */
 252 #define DID_NO_CONNECT  0x01    /* Couldn't connect before timeout period  */
 253 #define DID_BUS_BUSY    0x02    /* BUS stayed busy through time out period */
 254 #define DID_TIME_OUT    0x03    /* TIMED OUT for other reason              */
 255 #define DID_BAD_TARGET  0x04    /* BAD target.                             */
 256 #define DID_ABORT       0x05    /* Told to abort for some other reason     */
 257 #define DID_PARITY      0x06    /* Parity error                            */
 258 #define DID_ERROR       0x07    /* Internal error                          */
 259 #define DID_RESET       0x08    /* Reset by somebody.                      */
 260 #define DID_BAD_INTR    0x09    /* Got an interrupt we weren't expecting.  */
 261 #define DID_PASSTHROUGH 0x0a    /* Force command past mid-layer            */
 262 #define DID_SOFT_ERROR  0x0b    /* The low level driver just wish a retry  */
 263 #define DRIVER_OK       0x00    /* Driver status                           */
 264
 265 /*
 266  *  These indicate the error that occurred, and what is available.
 267  */
 268
 269 #define DRIVER_BUSY         0x01
 270 #define DRIVER_SOFT         0x02
 271 #define DRIVER_MEDIA        0x03
 272 #define DRIVER_ERROR        0x04
 273
 274 #define DRIVER_INVALID      0x05
 275 #define DRIVER_TIMEOUT      0x06
 276 #define DRIVER_HARD         0x07
 277 #define DRIVER_SENSE        0x08
 278
 279 #define SUGGEST_RETRY       0x10
 280 #define SUGGEST_ABORT       0x20
 281 #define SUGGEST_REMAP       0x30
 282 #define SUGGEST_DIE         0x40
 283 #define SUGGEST_SENSE       0x80
 284 #define SUGGEST_IS_OK       0xff
 285
 286 #define DRIVER_MASK         0x0f
 287 #define SUGGEST_MASK        0xf0
 288
 289 #define MAX_COMMAND_SIZE    12
 290
 291 /*
 292  *  SCSI command sets
 293  */
 294
 295 #define SCSI_UNKNOWN    0
 296 #define SCSI_1          1
 297 #define SCSI_1_CCS      2
 298 #define SCSI_2          3
 299 #define SCSI_3          4
 300
 301 /*
 302  *  Every SCSI command starts with a one byte OP-code.
 303  *  The next byte's high three bits are the LUN of the
 304  *  device.  Any multi-byte quantities are stored high byte
 305  *  first, and may have a 5 bit MSB in the same byte
 306  *  as the LUN.
 307  */
 308
 309 /*
 310  *  As the scsi do command functions are intelligent, and may need to
 311  *  redo a command, we need to keep track of the last command
 312  *  executed on each one.
 313  */
 314
 315 #define WAS_RESET       0x01
 316 #define WAS_TIMEDOUT    0x02
 317 #define WAS_SENSE       0x04
 318 #define IS_RESETTING    0x08
 319 #define IS_ABORTING     0x10
 320 #define ASKED_FOR_SENSE 0x20
 321 #define SYNC_RESET      0x40
 322
 323 #if defined(__mc68000__) || defined(CONFIG_APUS)
 324 #include <asm/pgtable.h>
 325 #define CONTIGUOUS_BUFFERS(X,Y) \
 326         (virt_to_phys((X)->b_data+(X)->b_size-1)+1==virt_to_phys((Y)->b_data))
 327 #else
 328 #define CONTIGUOUS_BUFFERS(X,Y) ((X->b_data+X->b_size) == Y->b_data)
 329 #endif
 330
 331
 332 /*
 333  * This is the crap from the old error handling code.  We have it in a special
 334  * place so that we can more easily delete it later on.
 335  */
 336 #include "scsi_obsolete.h"
 337
 338 /*
 339  * Add some typedefs so that we can prototyope a bunch of the functions.
 340  */
 341 typedef struct scsi_device Scsi_Device;
 342 typedef struct scsi_cmnd Scsi_Cmnd;
 343
 344 /*
 345  * Here is where we prototype most of the mid-layer.
 346  */
 347
 348 /*
 349  *  Initializes all SCSI devices.  This scans all scsi busses.
 350  */
 351
 352 extern int scsi_dev_init(void);
 353
 354
 355
 356 void *scsi_malloc(unsigned int);
 357 int scsi_free(void *, unsigned int);
 358 extern unsigned int scsi_logging_level;         /* What do we log? */
 359 extern unsigned int scsi_dma_free_sectors;      /* How much room do we have left */
 360 extern unsigned int scsi_need_isa_buffer;       /* True if some devices need indirection
 361                                                    * buffers */
 362 extern void scsi_make_blocked_list(void);
 363 extern volatile int in_scan_scsis;
 364 extern const unsigned char scsi_command_size[8];
 365
 366 /*
 367  * These are the error handling functions defined in scsi_error.c
 368  */
 369 extern void scsi_add_timer(Scsi_Cmnd * SCset, int timeout,
 370                            void (*complete) (Scsi_Cmnd *));
 371 extern void scsi_done(Scsi_Cmnd * SCpnt);
 372 extern int scsi_delete_timer(Scsi_Cmnd * SCset);
 373 extern void scsi_error_handler(void *host);
 374 extern int scsi_retry_command(Scsi_Cmnd *);
 375 extern void scsi_finish_command(Scsi_Cmnd *);
 376 extern int scsi_sense_valid(Scsi_Cmnd *);
 377 extern int scsi_decide_disposition(Scsi_Cmnd * SCpnt);
 378 extern int scsi_block_when_processing_errors(Scsi_Device *);
 379 extern void scsi_sleep(int);
 380
 381 /*
 382  *  scsi_abort aborts the current command that is executing on host host.
 383  *  The error code, if non zero is returned in the host byte, otherwise
 384  *  DID_ABORT is returned in the hostbyte.
 385  */
 386
 387 extern void scsi_do_cmd(Scsi_Cmnd *, const void *cmnd,
 388                         void *buffer, unsigned bufflen,
 389                         void (*done) (struct scsi_cmnd *),
 390                         int timeout, int retries);
 391
 392
 393 extern Scsi_Cmnd *scsi_allocate_device(struct request **, Scsi_Device *, int);
 394
 395 extern Scsi_Cmnd *scsi_request_queueable(struct request *, Scsi_Device *);
 396
 397 extern void scsi_release_command(Scsi_Cmnd *);
 398
 399 extern int max_scsi_hosts;
 400
 401 extern void proc_print_scsidevice(Scsi_Device *, char *, int *, int);
 402
 403 extern void print_command(unsigned char *);
 404 extern void print_sense(const char *, Scsi_Cmnd *);
 405 extern void print_driverbyte(int scsiresult);
 406 extern void print_hostbyte(int scsiresult);
 407
 408 /*
 409  *  The scsi_device struct contains what we know about each given scsi
 410  *  device.
 411  */
 412
 413 struct scsi_device {
 414 /* private: */
 415         /*
 416          * This information is private to the scsi mid-layer.  Wrapping it in a
 417          * struct private is a way of marking it in a sort of C++ type of way.
 418          */
 419         struct scsi_device *next;       /* Used for linked list */
 420         struct scsi_device *prev;       /* Used for linked list */
 421         wait_queue_head_t device_wait;  /* Used to wait if
 422                                            device is busy */
 423         struct Scsi_Host *host;
 424         volatile unsigned short device_busy;    /* commands actually active on low-level */
 425         void (*scsi_request_fn) (void);         /* Used to jumpstart things after an
 426                                                    * ioctl */
 427         Scsi_Cmnd *device_queue;        /* queue of SCSI Command structures */
 428
 429 /* public: */
 430         unsigned char id, lun, channel;
 431
 432         unsigned int manufacturer;      /* Manufacturer of device, for using
 433                                          * vendor-specific cmd's */
 434         int attached;           /* # of high level drivers attached to
 435                                  * this */
 436         int access_count;       /* Count of open channels/mounts */
 437
 438         void *hostdata;         /* available to low-level driver */
 439         char type;
 440         char scsi_level;
 441         char vendor[8], model[16], rev[4];
 442         unsigned char current_tag;      /* current tag */
 443         unsigned char sync_min_period;  /* Not less than this period */
 444         unsigned char sync_max_offset;  /* Not greater than this offset */
 445         unsigned char queue_depth;      /* How deep a queue to use */
 446
 447         unsigned online:1;
 448         unsigned writeable:1;
 449         unsigned removable:1;
 450         unsigned random:1;
 451         unsigned has_cmdblocks:1;
 452         unsigned changed:1;     /* Data invalid due to media change */
 453         unsigned busy:1;        /* Used to prevent races */
 454         unsigned lockable:1;    /* Able to prevent media removal */
 455         unsigned borken:1;      /* Tell the Seagate driver to be
 456                                  * painfully slow on this device */
 457         unsigned tagged_supported:1;    /* Supports SCSI-II tagged queuing */
 458         unsigned tagged_queue:1;        /* SCSI-II tagged queuing enabled */
 459         unsigned disconnect:1;  /* can disconnect */
 460         unsigned soft_reset:1;  /* Uses soft reset option */
 461         unsigned sync:1;        /* Negotiate for sync transfers */
 462         unsigned wide:1;        /* Negotiate for WIDE transfers */
 463         unsigned single_lun:1;  /* Indicates we should only allow I/O to
 464                                  * one of the luns for the device at a
 465                                  * time. */
 466         unsigned was_reset:1;   /* There was a bus reset on the bus for
 467                                  * this device */
 468         unsigned expecting_cc_ua:1;     /* Expecting a CHECK_CONDITION/UNIT_ATTN
 469                                          * because we did a bus reset. */
 470         unsigned device_blocked:1;      /* Device returned QUEUE_FULL. */
 471 };
 472
 473
 474 /*
 475  * The Scsi_Cmnd structure is used by scsi.c internally, and for communication
 476  * with low level drivers that support multiple outstanding commands.
 477  */
 478 typedef struct scsi_pointer {
 479         char *ptr;              /* data pointer */
 480         int this_residual;      /* left in this buffer */
 481         struct scatterlist *buffer;     /* which buffer */
 482         int buffers_residual;   /* how many buffers left */
 483
 484         volatile int Status;
 485         volatile int Message;
 486         volatile int have_data_in;
 487         volatile int sent_command;
 488         volatile int phase;
 489 } Scsi_Pointer;
 490
 491
 492 struct scsi_cmnd {
 493 /* private: */
 494         /*
 495          * This information is private to the scsi mid-layer.  Wrapping it in a
 496          * struct private is a way of marking it in a sort of C++ type of way.
 497          */
 498         struct Scsi_Host *host;
 499         unsigned short state;
 500         unsigned short owner;
 501         Scsi_Device *device;
 502         struct scsi_cmnd *next;
 503         struct scsi_cmnd *reset_chain;
 504
 505         int eh_state;           /* Used for state tracking in error handlr */
 506         void (*done) (struct scsi_cmnd *);      /* Mid-level done function */
 507         /*
 508            A SCSI Command is assigned a nonzero serial_number when internal_cmnd
 509            passes it to the driver's queue command function.  The serial_number
 510            is cleared when scsi_done is entered indicating that the command has
 511            been completed.  If a timeout occurs, the serial number at the moment
 512            of timeout is copied into serial_number_at_timeout.  By subsequently
 513            comparing the serial_number and serial_number_at_timeout fields
 514            during abort or reset processing, we can detect whether the command
 515            has already completed.  This also detects cases where the command has
 516            completed and the SCSI Command structure has already being reused
 517            for another command, so that we can avoid incorrectly aborting or
 518            resetting the new command.
 519          */
 520
 521         unsigned long serial_number;
 522         unsigned long serial_number_at_timeout;
 523
 524         int retries;
 525         int allowed;
 526         int timeout_per_command;
 527         int timeout_total;
 528         int timeout;
 529
 530         /*
 531          * We handle the timeout differently if it happens when a reset,
 532          * abort, etc are in process.
 533          */
 534         unsigned volatile char internal_timeout;
 535         struct scsi_cmnd *bh_next;      /* To enumerate the commands waiting
 536                                            to be processed. */
 537
 538 /* public: */
 539
 540         unsigned char target;
 541         unsigned char lun;
 542         unsigned char channel;
 543         unsigned char cmd_len;
 544         unsigned char old_cmd_len;
 545
 546         /* These elements define the operation we are about to perform */
 547         unsigned char cmnd[12];
 548         unsigned request_bufflen;       /* Actual request size */
 549
 550         struct timer_list eh_timeout;   /* Used to time out the command. */
 551         void *request_buffer;   /* Actual requested buffer */
 552
 553         /* These elements define the operation we ultimately want to perform */
 554         unsigned char data_cmnd[12];
 555         unsigned short old_use_sg;      /* We save  use_sg here when requesting
 556                                          * sense info */
 557         unsigned short use_sg;  /* Number of pieces of scatter-gather */
 558         unsigned short sglist_len;      /* size of malloc'd scatter-gather list */
 559         unsigned short abort_reason;    /* If the mid-level code requests an
 560                                          * abort, this is the reason. */
 561         unsigned bufflen;       /* Size of data buffer */
 562         void *buffer;           /* Data buffer */
 563
 564         unsigned underflow;     /* Return error if less than
 565                                    this amount is transfered */
 566
 567         unsigned transfersize;  /* How much we are guaranteed to
 568                                    transfer with each SCSI transfer
 569                                    (ie, between disconnect /
 570                                    reconnects.   Probably == sector
 571                                    size */
 572
 573
 574         struct request request; /* A copy of the command we are
 575                                    working on */
 576
 577         unsigned char sense_buffer[16];         /* Sense for this command,
 578                                                    needed */
 579
 580         unsigned flags;
 581
 582         /*
 583          * These two flags are used to track commands that are in the
 584          * mid-level queue.  The idea is that a command can be there for
 585          * one of two reasons - either the host is busy or the device is
 586          * busy.  Thus when a command on the host finishes, we only try
 587          * and requeue commands that we might expect to be queueable.
 588          */
 589         unsigned host_wait:1;
 590         unsigned device_wait:1;
 591
 592         /* These variables are for the cdrom only. Once we have variable size
 593          * buffers in the buffer cache, they will go away. */
 594         int this_count;
 595         /* End of special cdrom variables */
 596
 597         /* Low-level done function - can be used by low-level driver to point
 598          *        to completion function.  Not used by mid/upper level code. */
 599         void (*scsi_done) (struct scsi_cmnd *);
 600
 601         /*
 602          * The following fields can be written to by the host specific code.
 603          * Everything else should be left alone.
 604          */
 605
 606         Scsi_Pointer SCp;       /* Scratchpad used by some host adapters */
 607
 608         unsigned char *host_scribble;   /* The host adapter is allowed to
 609                                            * call scsi_malloc and get some memory
 610                                            * and hang it here.     The host adapter
 611                                            * is also expected to call scsi_free
 612                                            * to release this memory.  (The memory
 613                                            * obtained by scsi_malloc is guaranteed
 614                                            * to be at an address < 16Mb). */
 615
 616         int result;             /* Status code from lower level driver */
 617
 618         unsigned char tag;      /* SCSI-II queued command tag */
 619         unsigned long pid;      /* Process ID, starts at 0 */
 620 };
 621
 622
 623 /*
 624  * Definitions and prototypes used for scsi mid-level queue.
 625  */
 626 #define SCSI_MLQUEUE_HOST_BUSY   0x1055
 627 #define SCSI_MLQUEUE_DEVICE_BUSY 0x1056
 628
 629 extern int scsi_mlqueue_insert(Scsi_Cmnd * cmd, int reason);
 630 extern int scsi_mlqueue_finish(struct Scsi_Host *host, Scsi_Device * device);
 631
 632
 633 #if defined(MAJOR_NR) && (MAJOR_NR != SCSI_TAPE_MAJOR)
 634 #include "hosts.h"
 635
 636 static Scsi_Cmnd *end_scsi_request(Scsi_Cmnd * SCpnt, int uptodate, int sectors)
 637 {
 638         struct request *req;
 639         struct buffer_head *bh;
 640
 641         req = &SCpnt->request;
 642         req->errors = 0;
 643         if (!uptodate) {
 644                 printk(DEVICE_NAME " I/O error: dev %s, sector %lu\n",
 645                        kdevname(req->rq_dev), req->sector);
 646         }
 647         do {
 648                 if ((bh = req->bh) != NULL) {
 649                         req->bh = bh->b_reqnext;
 650                         req->nr_sectors -= bh->b_size >> 9;
 651                         req->sector += bh->b_size >> 9;
 652                         bh->b_reqnext = NULL;
 653                         bh->b_end_io(bh, uptodate);
 654                         sectors -= bh->b_size >> 9;
 655                         if ((bh = req->bh) != NULL) {
 656                                 req->current_nr_sectors = bh->b_size >> 9;
 657                                 if (req->nr_sectors < req->current_nr_sectors) {
 658                                         req->nr_sectors = req->current_nr_sectors;
 659                                         printk("end_scsi_request: buffer-list destroyed\n");
 660                                 }
 661                         }
 662                 }
 663         } while (sectors && bh);
 664         if (req->bh) {
 665                 req->buffer = bh->b_data;
 666                 return SCpnt;
 667         }
 668         DEVICE_OFF(req->rq_dev);
 669         if (req->sem != NULL) {
 670                 up(req->sem);
 671         }
 672         add_blkdev_randomness(MAJOR(req->rq_dev));
 673
 674         if (SCpnt->host->block) {
 675                 struct Scsi_Host *next;
 676
 677                 for (next = SCpnt->host->block; next != SCpnt->host;
 678                      next = next->block)
 679                         wake_up(&next->host_wait);
 680         }
 681         wake_up(&wait_for_request);
 682         wake_up(&SCpnt->device->device_wait);
 683         scsi_release_command(SCpnt);
 684         return NULL;
 685 }
 686
 687
 688 /* This is just like INIT_REQUEST, but we need to be aware of the fact
 689  * that an interrupt may start another request, so we run this with interrupts
 690  * turned off
 691  */
 692 #if MAJOR_NR == SCSI_DISK0_MAJOR
 693 #define CHECK_INITREQ_SD_MAJOR(major) SCSI_DISK_MAJOR(major)
 694 #else
 695 #define CHECK_INITREQ_SD_MAJOR(major) ((major) == MAJOR_NR)
 696 #endif
 697
 698 #define INIT_SCSI_REQUEST                               \
 699     if (!CURRENT) {                                     \
 700         CLEAR_INTR;                                     \
 701         return;                                         \
 702     }                                                   \
 703     if (!CHECK_INITREQ_SD_MAJOR(MAJOR(CURRENT->rq_dev)))\
 704         panic(DEVICE_NAME ": request list destroyed");  \
 705     if (CURRENT->bh) {                                  \
 706         if (!buffer_locked(CURRENT->bh))                \
 707             panic(DEVICE_NAME ": block not locked");    \
 708     }
 709 #endif
 710
 711 #define SCSI_SLEEP(QUEUE, CONDITION) {              \
 712     if (CONDITION) {                                \
 713         DECLARE_WAITQUEUE(wait, current);           \
 714         add_wait_queue(QUEUE, &wait);               \
 715         for(;;) {                                   \
 716         set_current_state(TASK_UNINTERRUPTIBLE);    \
 717         if (CONDITION) {                            \
 718             if (in_interrupt())                     \
 719                 panic("scsi: trying to call schedule() in interrupt" \
 720                       ", file %s, line %d.\n", __FILE__, __LINE__);  \
 721             schedule();                 \
 722         }                               \
 723         else                            \
 724             break;                      \
 725         }                               \
 726         remove_wait_queue(QUEUE, &wait);\
 727         current->state = TASK_RUNNING;  \
 728     }; }
 729
 730 #endif
 731
 732 /*
 733  * Overrides for Emacs so that we follow Linus's tabbing style.
 734  * Emacs will notice this stuff at the end of the file and automatically
 735  * adjust the settings for this buffer only.  This must remain at the end
 736  * of the file.
 737  * ---------------------------------------------------------------------------
 738  * Local variables:
 739  * c-indent-level: 4
 740  * c-brace-imaginary-offset: 0
 741  * c-brace-offset: -4
 742  * c-argdecl-indent: 4
 743  * c-label-offset: -4
 744  * c-continued-statement-offset: 4
 745  * c-continued-brace-offset: 0
 746  * indent-tabs-mode: nil
 747  * tab-width: 8
 748  * End:
 749  */