drivers/scsi/scsi.h

   1 /*
   2  *  scsi.h Copyright (C) 1992 Drew Eckhardt
   3  *         Copyright (C) 1993, 1994, 1995, 1998, 1999 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@andante.org 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 #include <linux/devfs_fs_kernel.h>
  20 #include <linux/proc_fs.h>
  21
  22 /*
  23  * Some of the public constants are being moved to this file.
  24  * We include it here so that what came from where is transparent.
  25  */
  26 #include <scsi/scsi.h>
  27
  28 #include <linux/random.h>
  29
  30 #include <asm/hardirq.h>
  31 #include <asm/scatterlist.h>
  32 #include <asm/io.h>
  33
  34 /*
  35  * These are the values that the SCpnt->sc_data_direction and
  36  * SRpnt->sr_data_direction can take.  These need to be set
  37  * The SCSI_DATA_UNKNOWN value is essentially the default.
  38  * In the event that the command creator didn't bother to
  39  * set a value, you will see SCSI_DATA_UNKNOWN.
  40  */
  41 #define SCSI_DATA_UNKNOWN       0
  42 #define SCSI_DATA_WRITE         1
  43 #define SCSI_DATA_READ          2
  44 #define SCSI_DATA_NONE          3
  45
  46 #ifdef CONFIG_PCI
  47 #include <linux/pci.h>
  48 #if ((SCSI_DATA_UNKNOWN == PCI_DMA_BIDIRECTIONAL) && (SCSI_DATA_WRITE == PCI_DMA_TODEVICE) && (SCSI_DATA_READ == PCI_DMA_FROMDEVICE) && (SCSI_DATA_NONE == PCI_DMA_NONE))
  49 #define scsi_to_pci_dma_dir(scsi_dir)   ((int)(scsi_dir))
  50 #else
  51 extern __inline__ int scsi_to_pci_dma_dir(unsigned char scsi_dir)
  52 {
  53         if (scsi_dir == SCSI_DATA_UNKNOWN)
  54                 return PCI_DMA_BIDIRECTIONAL;
  55         if (scsi_dir == SCSI_DATA_WRITE)
  56                 return PCI_DMA_TODEVICE;
  57         if (scsi_dir == SCSI_DATA_READ)
  58                 return PCI_DMA_FROMDEVICE;
  59         return PCI_DMA_NONE;
  60 }
  61 #endif
  62 #endif
  63
  64 #ifdef CONFIG_SBUS
  65 #include <asm/sbus.h>
  66 #if ((SCSI_DATA_UNKNOWN == SBUS_DMA_BIDIRECTIONAL) && (SCSI_DATA_WRITE == SBUS_DMA_TODEVICE) && (SCSI_DATA_READ == SBUS_DMA_FROMDEVICE) && (SCSI_DATA_NONE == SBUS_DMA_NONE))
  67 #define scsi_to_sbus_dma_dir(scsi_dir)  ((int)(scsi_dir))
  68 #else
  69 extern __inline__ int scsi_to_sbus_dma_dir(unsigned char scsi_dir)
  70 {
  71         if (scsi_dir == SCSI_DATA_UNKNOWN)
  72                 return SBUS_DMA_BIDIRECTIONAL;
  73         if (scsi_dir == SCSI_DATA_WRITE)
  74                 return SBUS_DMA_TODEVICE;
  75         if (scsi_dir == SCSI_DATA_READ)
  76                 return SBUS_DMA_FROMDEVICE;
  77         return SBUS_DMA_NONE;
  78 }
  79 #endif
  80 #endif
  81
  82 /*
  83  * Some defs, in case these are not defined elsewhere.
  84  */
  85 #ifndef TRUE
  86 #define TRUE 1
  87 #endif
  88 #ifndef FALSE
  89 #define FALSE 0
  90 #endif
  91
  92 #define MAX_SCSI_DEVICE_CODE 14
  93 extern const char *const scsi_device_types[MAX_SCSI_DEVICE_CODE];
  94
  95 #ifdef DEBUG
  96 #define SCSI_TIMEOUT (5*HZ)
  97 #else
  98 #define SCSI_TIMEOUT (2*HZ)
  99 #endif
 100
 101 /*
 102  * Used for debugging the new queueing code.  We want to make sure
 103  * that the lock state is consistent with design.  Only do this in
 104  * the user space simulator.
 105  */
 106 #define ASSERT_LOCK(_LOCK, _COUNT)
 107
 108 #if defined(CONFIG_SMP) && defined(CONFIG_USER_DEBUG)
 109 #undef ASSERT_LOCK
 110 #define ASSERT_LOCK(_LOCK,_COUNT)       \
 111         { if( (_LOCK)->lock != _COUNT )   \
 112                 panic("Lock count inconsistent %s %d\n", __FILE__, __LINE__); \
 113                                                                                        }
 114 #endif
 115
 116 /*
 117  *  Use these to separate status msg and our bytes
 118  *
 119  *  These are set by:
 120  *
 121  *      status byte = set from target device
 122  *      msg_byte    = return status from host adapter itself.
 123  *      host_byte   = set by low-level driver to indicate status.
 124  *      driver_byte = set by mid-level.
 125  */
 126 #define status_byte(result) (((result) >> 1) & 0x1f)
 127 #define msg_byte(result)    (((result) >> 8) & 0xff)
 128 #define host_byte(result)   (((result) >> 16) & 0xff)
 129 #define driver_byte(result) (((result) >> 24) & 0xff)
 130 #define suggestion(result)  (driver_byte(result) & SUGGEST_MASK)
 131
 132 #define sense_class(sense)  (((sense) >> 4) & 0x7)
 133 #define sense_error(sense)  ((sense) & 0xf)
 134 #define sense_valid(sense)  ((sense) & 0x80);
 135
 136 #define NEEDS_RETRY     0x2001
 137 #define SUCCESS         0x2002
 138 #define FAILED          0x2003
 139 #define QUEUED          0x2004
 140 #define SOFT_ERROR      0x2005
 141 #define ADD_TO_MLQUEUE  0x2006
 142
 143 /*
 144  * These are the values that scsi_cmd->state can take.
 145  */
 146 #define SCSI_STATE_TIMEOUT         0x1000
 147 #define SCSI_STATE_FINISHED        0x1001
 148 #define SCSI_STATE_FAILED          0x1002
 149 #define SCSI_STATE_QUEUED          0x1003
 150 #define SCSI_STATE_UNUSED          0x1006
 151 #define SCSI_STATE_DISCONNECTING   0x1008
 152 #define SCSI_STATE_INITIALIZING    0x1009
 153 #define SCSI_STATE_BHQUEUE         0x100a
 154 #define SCSI_STATE_MLQUEUE         0x100b
 155
 156 /*
 157  * These are the values that the owner field can take.
 158  * They are used as an indication of who the command belongs to.
 159  */
 160 #define SCSI_OWNER_HIGHLEVEL      0x100
 161 #define SCSI_OWNER_MIDLEVEL       0x101
 162 #define SCSI_OWNER_LOWLEVEL       0x102
 163 #define SCSI_OWNER_ERROR_HANDLER  0x103
 164 #define SCSI_OWNER_BH_HANDLER     0x104
 165 #define SCSI_OWNER_NOBODY         0x105
 166
 167 #define COMMAND_SIZE(opcode) scsi_command_size[((opcode) >> 5) & 7]
 168
 169 #define IDENTIFY_BASE       0x80
 170 #define IDENTIFY(can_disconnect, lun)   (IDENTIFY_BASE |\
 171                      ((can_disconnect) ?  0x40 : 0) |\
 172                      ((lun) & 0x07))
 173
 174
 175 /*
 176  * This defines the scsi logging feature.  It is a means by which the
 177  * user can select how much information they get about various goings on,
 178  * and it can be really useful for fault tracing.  The logging word is divided
 179  * into 8 nibbles, each of which describes a loglevel.  The division of things
 180  * is somewhat arbitrary, and the division of the word could be changed if it
 181  * were really needed for any reason.  The numbers below are the only place where these
 182  * are specified.  For a first go-around, 3 bits is more than enough, since this
 183  * gives 8 levels of logging (really 7, since 0 is always off).  Cutting to 2 bits
 184  * might be wise at some point.
 185  */
 186
 187 #define SCSI_LOG_ERROR_SHIFT              0
 188 #define SCSI_LOG_TIMEOUT_SHIFT            3
 189 #define SCSI_LOG_SCAN_SHIFT               6
 190 #define SCSI_LOG_MLQUEUE_SHIFT            9
 191 #define SCSI_LOG_MLCOMPLETE_SHIFT         12
 192 #define SCSI_LOG_LLQUEUE_SHIFT            15
 193 #define SCSI_LOG_LLCOMPLETE_SHIFT         18
 194 #define SCSI_LOG_HLQUEUE_SHIFT            21
 195 #define SCSI_LOG_HLCOMPLETE_SHIFT         24
 196 #define SCSI_LOG_IOCTL_SHIFT              27
 197
 198 #define SCSI_LOG_ERROR_BITS               3
 199 #define SCSI_LOG_TIMEOUT_BITS             3
 200 #define SCSI_LOG_SCAN_BITS                3
 201 #define SCSI_LOG_MLQUEUE_BITS             3
 202 #define SCSI_LOG_MLCOMPLETE_BITS          3
 203 #define SCSI_LOG_LLQUEUE_BITS             3
 204 #define SCSI_LOG_LLCOMPLETE_BITS          3
 205 #define SCSI_LOG_HLQUEUE_BITS             3
 206 #define SCSI_LOG_HLCOMPLETE_BITS          3
 207 #define SCSI_LOG_IOCTL_BITS               3
 208
 209 #if CONFIG_SCSI_LOGGING
 210
 211 #define SCSI_CHECK_LOGGING(SHIFT, BITS, LEVEL, CMD)     \
 212 {                                                       \
 213         unsigned int mask;                              \
 214                                                         \
 215         mask = (1 << (BITS)) - 1;                       \
 216         if( ((scsi_logging_level >> (SHIFT)) & mask) > (LEVEL) ) \
 217         {                                               \
 218                 (CMD);                                  \
 219         }                                               \
 220 }
 221
 222 #define SCSI_SET_LOGGING(SHIFT, BITS, LEVEL)            \
 223 {                                                       \
 224         unsigned int mask;                              \
 225                                                         \
 226         mask = ((1 << (BITS)) - 1) << SHIFT;            \
 227         scsi_logging_level = ((scsi_logging_level & ~mask) \
 228                               | ((LEVEL << SHIFT) & mask));     \
 229 }
 230
 231
 232
 233 #else
 234
 235 /*
 236  * With no logging enabled, stub these out so they don't do anything.
 237  */
 238 #define SCSI_SET_LOGGING(SHIFT, BITS, LEVEL)
 239
 240 #define SCSI_CHECK_LOGGING(SHIFT, BITS, LEVEL, CMD)
 241 #endif
 242
 243 /*
 244  * These are the macros that are actually used throughout the code to
 245  * log events.  If logging isn't enabled, they are no-ops and will be
 246  * completely absent from the user's code.
 247  *
 248  * The 'set' versions of the macros are really intended to only be called
 249  * from the /proc filesystem, and in production kernels this will be about
 250  * all that is ever used.  It could be useful in a debugging environment to
 251  * bump the logging level when certain strange events are detected, however.
 252  */
 253 #define SCSI_LOG_ERROR_RECOVERY(LEVEL,CMD)  \
 254         SCSI_CHECK_LOGGING(SCSI_LOG_ERROR_SHIFT, SCSI_LOG_ERROR_BITS, LEVEL,CMD);
 255 #define SCSI_LOG_TIMEOUT(LEVEL,CMD)  \
 256         SCSI_CHECK_LOGGING(SCSI_LOG_TIMEOUT_SHIFT, SCSI_LOG_TIMEOUT_BITS, LEVEL,CMD);
 257 #define SCSI_LOG_SCAN_BUS(LEVEL,CMD)  \
 258         SCSI_CHECK_LOGGING(SCSI_LOG_SCAN_SHIFT, SCSI_LOG_SCAN_BITS, LEVEL,CMD);
 259 #define SCSI_LOG_MLQUEUE(LEVEL,CMD)  \
 260         SCSI_CHECK_LOGGING(SCSI_LOG_MLQUEUE_SHIFT, SCSI_LOG_MLQUEUE_BITS, LEVEL,CMD);
 261 #define SCSI_LOG_MLCOMPLETE(LEVEL,CMD)  \
 262         SCSI_CHECK_LOGGING(SCSI_LOG_MLCOMPLETE_SHIFT, SCSI_LOG_MLCOMPLETE_BITS, LEVEL,CMD);
 263 #define SCSI_LOG_LLQUEUE(LEVEL,CMD)  \
 264         SCSI_CHECK_LOGGING(SCSI_LOG_LLQUEUE_SHIFT, SCSI_LOG_LLQUEUE_BITS, LEVEL,CMD);
 265 #define SCSI_LOG_LLCOMPLETE(LEVEL,CMD)  \
 266         SCSI_CHECK_LOGGING(SCSI_LOG_LLCOMPLETE_SHIFT, SCSI_LOG_LLCOMPLETE_BITS, LEVEL,CMD);
 267 #define SCSI_LOG_HLQUEUE(LEVEL,CMD)  \
 268         SCSI_CHECK_LOGGING(SCSI_LOG_HLQUEUE_SHIFT, SCSI_LOG_HLQUEUE_BITS, LEVEL,CMD);
 269 #define SCSI_LOG_HLCOMPLETE(LEVEL,CMD)  \
 270         SCSI_CHECK_LOGGING(SCSI_LOG_HLCOMPLETE_SHIFT, SCSI_LOG_HLCOMPLETE_BITS, LEVEL,CMD);
 271 #define SCSI_LOG_IOCTL(LEVEL,CMD)  \
 272         SCSI_CHECK_LOGGING(SCSI_LOG_IOCTL_SHIFT, SCSI_LOG_IOCTL_BITS, LEVEL,CMD);
 273
 274
 275 #define SCSI_SET_ERROR_RECOVERY_LOGGING(LEVEL)  \
 276         SCSI_SET_LOGGING(SCSI_LOG_ERROR_SHIFT, SCSI_LOG_ERROR_BITS, LEVEL);
 277 #define SCSI_SET_TIMEOUT_LOGGING(LEVEL)  \
 278         SCSI_SET_LOGGING(SCSI_LOG_TIMEOUT_SHIFT, SCSI_LOG_TIMEOUT_BITS, LEVEL);
 279 #define SCSI_SET_SCAN_BUS_LOGGING(LEVEL)  \
 280         SCSI_SET_LOGGING(SCSI_LOG_SCAN_SHIFT, SCSI_LOG_SCAN_BITS, LEVEL);
 281 #define SCSI_SET_MLQUEUE_LOGGING(LEVEL)  \
 282         SCSI_SET_LOGGING(SCSI_LOG_MLQUEUE_SHIFT, SCSI_LOG_MLQUEUE_BITS, LEVEL);
 283 #define SCSI_SET_MLCOMPLETE_LOGGING(LEVEL)  \
 284         SCSI_SET_LOGGING(SCSI_LOG_MLCOMPLETE_SHIFT, SCSI_LOG_MLCOMPLETE_BITS, LEVEL);
 285 #define SCSI_SET_LLQUEUE_LOGGING(LEVEL)  \
 286         SCSI_SET_LOGGING(SCSI_LOG_LLQUEUE_SHIFT, SCSI_LOG_LLQUEUE_BITS, LEVEL);
 287 #define SCSI_SET_LLCOMPLETE_LOGGING(LEVEL)  \
 288         SCSI_SET_LOGGING(SCSI_LOG_LLCOMPLETE_SHIFT, SCSI_LOG_LLCOMPLETE_BITS, LEVEL);
 289 #define SCSI_SET_HLQUEUE_LOGGING(LEVEL)  \
 290         SCSI_SET_LOGGING(SCSI_LOG_HLQUEUE_SHIFT, SCSI_LOG_HLQUEUE_BITS, LEVEL);
 291 #define SCSI_SET_HLCOMPLETE_LOGGING(LEVEL)  \
 292         SCSI_SET_LOGGING(SCSI_LOG_HLCOMPLETE_SHIFT, SCSI_LOG_HLCOMPLETE_BITS, LEVEL);
 293 #define SCSI_SET_IOCTL_LOGGING(LEVEL)  \
 294         SCSI_SET_LOGGING(SCSI_LOG_IOCTL_SHIFT, SCSI_LOG_IOCTL_BITS, LEVEL);
 295
 296 /*
 297  *  the return of the status word will be in the following format :
 298  *  The low byte is the status returned by the SCSI command,
 299  *  with vendor specific bits masked.
 300  *
 301  *  The next byte is the message which followed the SCSI status.
 302  *  This allows a stos to be used, since the Intel is a little
 303  *  endian machine.
 304  *
 305  *  The final byte is a host return code, which is one of the following.
 306  *
 307  *  IE
 308  *  lsb     msb
 309  *  status  msg host code
 310  *
 311  *  Our errors returned by OUR driver, NOT SCSI message.  Or'd with
 312  *  SCSI message passed back to driver <IF any>.
 313  */
 314
 315
 316 #define DID_OK          0x00    /* NO error                                */
 317 #define DID_NO_CONNECT  0x01    /* Couldn't connect before timeout period  */
 318 #define DID_BUS_BUSY    0x02    /* BUS stayed busy through time out period */
 319 #define DID_TIME_OUT    0x03    /* TIMED OUT for other reason              */
 320 #define DID_BAD_TARGET  0x04    /* BAD target.                             */
 321 #define DID_ABORT       0x05    /* Told to abort for some other reason     */
 322 #define DID_PARITY      0x06    /* Parity error                            */
 323 #define DID_ERROR       0x07    /* Internal error                          */
 324 #define DID_RESET       0x08    /* Reset by somebody.                      */
 325 #define DID_BAD_INTR    0x09    /* Got an interrupt we weren't expecting.  */
 326 #define DID_PASSTHROUGH 0x0a    /* Force command past mid-layer            */
 327 #define DID_SOFT_ERROR  0x0b    /* The low level driver just wish a retry  */
 328 #define DRIVER_OK       0x00    /* Driver status                           */
 329
 330 /*
 331  *  These indicate the error that occurred, and what is available.
 332  */
 333
 334 #define DRIVER_BUSY         0x01
 335 #define DRIVER_SOFT         0x02
 336 #define DRIVER_MEDIA        0x03
 337 #define DRIVER_ERROR        0x04
 338
 339 #define DRIVER_INVALID      0x05
 340 #define DRIVER_TIMEOUT      0x06
 341 #define DRIVER_HARD         0x07
 342 #define DRIVER_SENSE        0x08
 343
 344 #define SUGGEST_RETRY       0x10
 345 #define SUGGEST_ABORT       0x20
 346 #define SUGGEST_REMAP       0x30
 347 #define SUGGEST_DIE         0x40
 348 #define SUGGEST_SENSE       0x80
 349 #define SUGGEST_IS_OK       0xff
 350
 351 #define DRIVER_MASK         0x0f
 352 #define SUGGEST_MASK        0xf0
 353
 354 #define MAX_COMMAND_SIZE    12
 355 #define SCSI_SENSE_BUFFERSIZE   64
 356
 357 /*
 358  *  SCSI command sets
 359  */
 360
 361 #define SCSI_UNKNOWN    0
 362 #define SCSI_1          1
 363 #define SCSI_1_CCS      2
 364 #define SCSI_2          3
 365 #define SCSI_3          4
 366
 367 /*
 368  *  Every SCSI command starts with a one byte OP-code.
 369  *  The next byte's high three bits are the LUN of the
 370  *  device.  Any multi-byte quantities are stored high byte
 371  *  first, and may have a 5 bit MSB in the same byte
 372  *  as the LUN.
 373  */
 374
 375 /*
 376  *  As the scsi do command functions are intelligent, and may need to
 377  *  redo a command, we need to keep track of the last command
 378  *  executed on each one.
 379  */
 380
 381 #define WAS_RESET       0x01
 382 #define WAS_TIMEDOUT    0x02
 383 #define WAS_SENSE       0x04
 384 #define IS_RESETTING    0x08
 385 #define IS_ABORTING     0x10
 386 #define ASKED_FOR_SENSE 0x20
 387 #define SYNC_RESET      0x40
 388
 389 #if defined(__mc68000__) || defined(CONFIG_APUS)
 390 #include <asm/pgtable.h>
 391 #define CONTIGUOUS_BUFFERS(X,Y) \
 392         (virt_to_phys((X)->b_data+(X)->b_size-1)+1==virt_to_phys((Y)->b_data))
 393 #else
 394 #define CONTIGUOUS_BUFFERS(X,Y) ((X->b_data+X->b_size) == Y->b_data)
 395 #endif
 396
 397
 398 /*
 399  * This is the crap from the old error handling code.  We have it in a special
 400  * place so that we can more easily delete it later on.
 401  */
 402 #include "scsi_obsolete.h"
 403
 404 /*
 405  * Add some typedefs so that we can prototyope a bunch of the functions.
 406  */
 407 typedef struct scsi_device Scsi_Device;
 408 typedef struct scsi_cmnd Scsi_Cmnd;
 409 typedef struct scsi_request Scsi_Request;
 410
 411 #define SCSI_CMND_MAGIC 0xE25C23A5
 412 #define SCSI_REQ_MAGIC  0x75F6D354
 413
 414 /*
 415  * Here is where we prototype most of the mid-layer.
 416  */
 417
 418 /*
 419  *  Initializes all SCSI devices.  This scans all scsi busses.
 420  */
 421
 422 extern unsigned int scsi_logging_level;         /* What do we log? */
 423 extern unsigned int scsi_dma_free_sectors;      /* How much room do we have left */
 424 extern unsigned int scsi_need_isa_buffer;       /* True if some devices need indirection
 425                                                    * buffers */
 426 extern volatile int in_scan_scsis;
 427 extern const unsigned char scsi_command_size[8];
 428
 429
 430 /*
 431  * These are the error handling functions defined in scsi_error.c
 432  */
 433 extern void scsi_times_out(Scsi_Cmnd * SCpnt);
 434 extern void scsi_add_timer(Scsi_Cmnd * SCset, int timeout,
 435                            void (*complete) (Scsi_Cmnd *));
 436 extern int scsi_delete_timer(Scsi_Cmnd * SCset);
 437 extern void scsi_error_handler(void *host);
 438 extern int scsi_sense_valid(Scsi_Cmnd *);
 439 extern int scsi_decide_disposition(Scsi_Cmnd * SCpnt);
 440 extern int scsi_block_when_processing_errors(Scsi_Device *);
 441 extern void scsi_sleep(int);
 442
 443 /*
 444  * Prototypes for functions in scsicam.c
 445  */
 446 extern int  scsi_partsize(struct buffer_head *bh, unsigned long capacity,
 447                     unsigned int *cyls, unsigned int *hds,
 448                     unsigned int *secs);
 449
 450 /*
 451  * Prototypes for functions in scsi_dma.c
 452  */
 453 void scsi_resize_dma_pool(void);
 454 int scsi_init_minimal_dma_pool(void);
 455 void *scsi_malloc(unsigned int);
 456 int scsi_free(void *, unsigned int);
 457
 458 /*
 459  * Prototypes for functions in scsi_merge.c
 460  */
 461 extern void recount_segments(Scsi_Cmnd * SCpnt);
 462 extern void initialize_merge_fn(Scsi_Device * SDpnt);
 463
 464 /*
 465  * Prototypes for functions in scsi_queue.c
 466  */
 467 extern int scsi_mlqueue_insert(Scsi_Cmnd * cmd, int reason);
 468
 469 /*
 470  * Prototypes for functions in scsi_lib.c
 471  */
 472 extern int scsi_maybe_unblock_host(Scsi_Device * SDpnt);
 473 extern Scsi_Cmnd *scsi_end_request(Scsi_Cmnd * SCpnt, int uptodate,
 474                                    int sectors);
 475 extern struct Scsi_Device_Template *scsi_get_request_dev(struct request *);
 476 extern int scsi_init_cmd_errh(Scsi_Cmnd * SCpnt);
 477 extern int scsi_insert_special_cmd(Scsi_Cmnd * SCpnt, int);
 478 extern void scsi_io_completion(Scsi_Cmnd * SCpnt, int good_sectors,
 479                                int block_sectors);
 480 extern void scsi_queue_next_request(request_queue_t * q, Scsi_Cmnd * SCpnt);
 481 extern void scsi_request_fn(request_queue_t * q);
 482 extern int scsi_starvation_completion(Scsi_Device * SDpnt);
 483
 484 /*
 485  * Prototypes for functions in scsi.c
 486  */
 487 extern int scsi_dispatch_cmd(Scsi_Cmnd * SCpnt);
 488 extern void scsi_bottom_half_handler(void);
 489 extern void scsi_release_commandblocks(Scsi_Device * SDpnt);
 490 extern void scsi_build_commandblocks(Scsi_Device * SDpnt);
 491 extern void scsi_done(Scsi_Cmnd * SCpnt);
 492 extern void scsi_finish_command(Scsi_Cmnd *);
 493 extern int scsi_retry_command(Scsi_Cmnd *);
 494 extern Scsi_Cmnd *scsi_allocate_device(Scsi_Device *, int, int);
 495 extern void __scsi_release_command(Scsi_Cmnd *);
 496 extern void scsi_release_command(Scsi_Cmnd *);
 497 extern void scsi_do_cmd(Scsi_Cmnd *, const void *cmnd,
 498                         void *buffer, unsigned bufflen,
 499                         void (*done) (struct scsi_cmnd *),
 500                         int timeout, int retries);
 501 extern int scsi_dev_init(void);
 502
 503 /*
 504  * Newer request-based interfaces.
 505  */
 506 extern Scsi_Request *scsi_allocate_request(Scsi_Device *);
 507 extern void scsi_release_request(Scsi_Request *);
 508 extern void scsi_wait_req(Scsi_Request *, const void *cmnd,
 509                           void *buffer, unsigned bufflen,
 510                           int timeout, int retries);
 511
 512 extern void scsi_do_req(Scsi_Request *, const void *cmnd,
 513                         void *buffer, unsigned bufflen,
 514                         void (*done) (struct scsi_cmnd *),
 515                         int timeout, int retries);
 516 extern int scsi_insert_special_req(Scsi_Request * SRpnt, int);
 517 extern void scsi_init_cmd_from_req(Scsi_Cmnd *, Scsi_Request *);
 518
 519
 520 /*
 521  * Prototypes for functions/data in hosts.c
 522  */
 523 extern int max_scsi_hosts;
 524
 525 /*
 526  * Prototypes for functions in scsi_proc.c
 527  */
 528 extern void proc_print_scsidevice(Scsi_Device *, char *, int *, int);
 529 extern struct proc_dir_entry *proc_scsi;
 530
 531 /*
 532  * Prototypes for functions in constants.c
 533  */
 534 extern void print_command(unsigned char *);
 535 extern void print_sense(const char *, Scsi_Cmnd *);
 536 extern void print_req_sense(const char *, Scsi_Request *);
 537 extern void print_driverbyte(int scsiresult);
 538 extern void print_hostbyte(int scsiresult);
 539 extern void print_status (int status);
 540
 541 /*
 542  *  The scsi_device struct contains what we know about each given scsi
 543  *  device.
 544  *
 545  * FIXME(eric) - one of the great regrets that I have is that I failed to define
 546  * these structure elements as something like sdev_foo instead of foo.  This would
 547  * make it so much easier to grep through sources and so forth.  I propose that
 548  * all new elements that get added to these structures follow this convention.
 549  * As time goes on and as people have the stomach for it, it should be possible to
 550  * go back and retrofit at least some of the elements here with with the prefix.
 551  */
 552
 553 struct scsi_device {
 554 /* private: */
 555         /*
 556          * This information is private to the scsi mid-layer.  Wrapping it in a
 557          * struct private is a way of marking it in a sort of C++ type of way.
 558          */
 559         struct scsi_device *next;       /* Used for linked list */
 560         struct scsi_device *prev;       /* Used for linked list */
 561         wait_queue_head_t   scpnt_wait; /* Used to wait if
 562                                            device is busy */
 563         struct Scsi_Host *host;
 564         request_queue_t request_queue;
 565         atomic_t                device_active; /* commands checked out for device */
 566         volatile unsigned short device_busy;    /* commands actually active on low-level */
 567         int (*scsi_init_io_fn) (Scsi_Cmnd *);   /* Used to initialize
 568                                                    new request */
 569         Scsi_Cmnd *device_queue;        /* queue of SCSI Command structures */
 570
 571 /* public: */
 572         unsigned int id, lun, channel;
 573
 574         unsigned int manufacturer;      /* Manufacturer of device, for using
 575                                          * vendor-specific cmd's */
 576         unsigned sector_size;   /* size in bytes */
 577
 578         int attached;           /* # of high level drivers attached to
 579                                  * this */
 580         int access_count;       /* Count of open channels/mounts */
 581
 582         void *hostdata;         /* available to low-level driver */
 583         devfs_handle_t de;      /* directory for the device      */
 584         char type;
 585         char scsi_level;
 586         char vendor[8], model[16], rev[4];
 587         unsigned char current_tag;      /* current tag */
 588         unsigned char sync_min_period;  /* Not less than this period */
 589         unsigned char sync_max_offset;  /* Not greater than this offset */
 590         unsigned char queue_depth;      /* How deep a queue to use */
 591
 592         unsigned online:1;
 593         unsigned writeable:1;
 594         unsigned removable:1;
 595         unsigned random:1;
 596         unsigned has_cmdblocks:1;
 597         unsigned changed:1;     /* Data invalid due to media change */
 598         unsigned busy:1;        /* Used to prevent races */
 599         unsigned lockable:1;    /* Able to prevent media removal */
 600         unsigned borken:1;      /* Tell the Seagate driver to be
 601                                  * painfully slow on this device */
 602         unsigned tagged_supported:1;    /* Supports SCSI-II tagged queuing */
 603         unsigned tagged_queue:1;        /* SCSI-II tagged queuing enabled */
 604         unsigned disconnect:1;  /* can disconnect */
 605         unsigned soft_reset:1;  /* Uses soft reset option */
 606         unsigned sync:1;        /* Negotiate for sync transfers */
 607         unsigned wide:1;        /* Negotiate for WIDE transfers */
 608         unsigned single_lun:1;  /* Indicates we should only allow I/O to
 609                                  * one of the luns for the device at a
 610                                  * time. */
 611         unsigned was_reset:1;   /* There was a bus reset on the bus for
 612                                  * this device */
 613         unsigned expecting_cc_ua:1;     /* Expecting a CHECK_CONDITION/UNIT_ATTN
 614                                          * because we did a bus reset. */
 615         unsigned device_blocked:1;      /* Device returned QUEUE_FULL. */
 616         unsigned ten:1;         /* support ten byte read / write */
 617         unsigned remap:1;       /* support remapping  */
 618         unsigned starved:1;     /* unable to process commands because
 619                                    host busy */
 620 };
 621
 622
 623 /*
 624  * The Scsi_Cmnd structure is used by scsi.c internally, and for communication
 625  * with low level drivers that support multiple outstanding commands.
 626  */
 627 typedef struct scsi_pointer {
 628         char *ptr;              /* data pointer */
 629         int this_residual;      /* left in this buffer */
 630         struct scatterlist *buffer;     /* which buffer */
 631         int buffers_residual;   /* how many buffers left */
 632
 633         volatile int Status;
 634         volatile int Message;
 635         volatile int have_data_in;
 636         volatile int sent_command;
 637         volatile int phase;
 638 } Scsi_Pointer;
 639
 640 /*
 641  * This is essentially a slimmed down version of Scsi_Cmnd.  The point of
 642  * having this is that requests that are injected into the queue as result
 643  * of things like ioctls and character devices shouldn't be using a
 644  * Scsi_Cmnd until such a time that the command is actually at the head
 645  * of the queue and being sent to the driver.
 646  */
 647 struct scsi_request {
 648         int     sr_magic;
 649         int     sr_result;      /* Status code from lower level driver */
 650         unsigned char sr_sense_buffer[SCSI_SENSE_BUFFERSIZE];           /* obtained by REQUEST SENSE
 651                                                  * when CHECK CONDITION is
 652                                                  * received on original command
 653                                                  * (auto-sense) */
 654
 655         struct Scsi_Host *sr_host;
 656         Scsi_Device *sr_device;
 657         Scsi_Cmnd *sr_command;
 658         struct request sr_request;      /* A copy of the command we are
 659                                    working on */
 660         unsigned sr_bufflen;    /* Size of data buffer */
 661         void *sr_buffer;                /* Data buffer */
 662         int sr_allowed;
 663         unsigned char sr_data_direction;
 664         unsigned char sr_cmd_len;
 665         unsigned char sr_cmnd[MAX_COMMAND_SIZE];
 666         void (*sr_done) (struct scsi_cmnd *);   /* Mid-level done function */
 667         int sr_timeout_per_command;
 668         unsigned short sr_use_sg;       /* Number of pieces of scatter-gather */
 669         unsigned short sr_sglist_len;   /* size of malloc'd scatter-gather list */
 670         unsigned sr_underflow;  /* Return error if less than
 671                                    this amount is transfered */
 672 };
 673
 674 /*
 675  * FIXME(eric) - one of the great regrets that I have is that I failed to define
 676  * these structure elements as something like sc_foo instead of foo.  This would
 677  * make it so much easier to grep through sources and so forth.  I propose that
 678  * all new elements that get added to these structures follow this convention.
 679  * As time goes on and as people have the stomach for it, it should be possible to
 680  * go back and retrofit at least some of the elements here with with the prefix.
 681  */
 682 struct scsi_cmnd {
 683         int     sc_magic;
 684 /* private: */
 685         /*
 686          * This information is private to the scsi mid-layer.  Wrapping it in a
 687          * struct private is a way of marking it in a sort of C++ type of way.
 688          */
 689         struct Scsi_Host *host;
 690         unsigned short state;
 691         unsigned short owner;
 692         Scsi_Device *device;
 693         Scsi_Request *sc_request;
 694         struct scsi_cmnd *next;
 695         struct scsi_cmnd *reset_chain;
 696
 697         int eh_state;           /* Used for state tracking in error handlr */
 698         void (*done) (struct scsi_cmnd *);      /* Mid-level done function */
 699         /*
 700            A SCSI Command is assigned a nonzero serial_number when internal_cmnd
 701            passes it to the driver's queue command function.  The serial_number
 702            is cleared when scsi_done is entered indicating that the command has
 703            been completed.  If a timeout occurs, the serial number at the moment
 704            of timeout is copied into serial_number_at_timeout.  By subsequently
 705            comparing the serial_number and serial_number_at_timeout fields
 706            during abort or reset processing, we can detect whether the command
 707            has already completed.  This also detects cases where the command has
 708            completed and the SCSI Command structure has already being reused
 709            for another command, so that we can avoid incorrectly aborting or
 710            resetting the new command.
 711          */
 712
 713         unsigned long serial_number;
 714         unsigned long serial_number_at_timeout;
 715
 716         int retries;
 717         int allowed;
 718         int timeout_per_command;
 719         int timeout_total;
 720         int timeout;
 721
 722         /*
 723          * We handle the timeout differently if it happens when a reset,
 724          * abort, etc are in process.
 725          */
 726         unsigned volatile char internal_timeout;
 727         struct scsi_cmnd *bh_next;      /* To enumerate the commands waiting
 728                                            to be processed. */
 729
 730 /* public: */
 731
 732         unsigned int target;
 733         unsigned int lun;
 734         unsigned int channel;
 735         unsigned char cmd_len;
 736         unsigned char old_cmd_len;
 737         unsigned char sc_data_direction;
 738         unsigned char sc_old_data_direction;
 739
 740         /* These elements define the operation we are about to perform */
 741         unsigned char cmnd[MAX_COMMAND_SIZE];
 742         unsigned request_bufflen;       /* Actual request size */
 743
 744         struct timer_list eh_timeout;   /* Used to time out the command. */
 745         void *request_buffer;   /* Actual requested buffer */
 746
 747         /* These elements define the operation we ultimately want to perform */
 748         unsigned char data_cmnd[MAX_COMMAND_SIZE];
 749         unsigned short old_use_sg;      /* We save  use_sg here when requesting
 750                                          * sense info */
 751         unsigned short use_sg;  /* Number of pieces of scatter-gather */
 752         unsigned short sglist_len;      /* size of malloc'd scatter-gather list */
 753         unsigned short abort_reason;    /* If the mid-level code requests an
 754                                          * abort, this is the reason. */
 755         unsigned bufflen;       /* Size of data buffer */
 756         void *buffer;           /* Data buffer */
 757
 758         unsigned underflow;     /* Return error if less than
 759                                    this amount is transfered */
 760         unsigned old_underflow; /* save underflow here when reusing the
 761                                  * command for error handling */
 762
 763         unsigned transfersize;  /* How much we are guaranteed to
 764                                    transfer with each SCSI transfer
 765                                    (ie, between disconnect /
 766                                    reconnects.   Probably == sector
 767                                    size */
 768
 769         int resid;              /* Number of bytes requested to be
 770                                    transferred less actual number
 771                                    transferred (0 if not supported) */
 772
 773         struct request request; /* A copy of the command we are
 774                                    working on */
 775
 776         unsigned char sense_buffer[SCSI_SENSE_BUFFERSIZE];              /* obtained by REQUEST SENSE
 777                                                  * when CHECK CONDITION is
 778                                                  * received on original command
 779                                                  * (auto-sense) */
 780
 781         unsigned flags;
 782
 783         /*
 784          * Used to indicate that a command which has timed out also
 785          * completed normally.  Typically the completion function will
 786          * do nothing but set this flag in this instance because the
 787          * timeout handler is already running.
 788          */
 789         unsigned done_late:1;
 790
 791         /* Low-level done function - can be used by low-level driver to point
 792          *        to completion function.  Not used by mid/upper level code. */
 793         void (*scsi_done) (struct scsi_cmnd *);
 794
 795         /*
 796          * The following fields can be written to by the host specific code.
 797          * Everything else should be left alone.
 798          */
 799
 800         Scsi_Pointer SCp;       /* Scratchpad used by some host adapters */
 801
 802         unsigned char *host_scribble;   /* The host adapter is allowed to
 803                                            * call scsi_malloc and get some memory
 804                                            * and hang it here.     The host adapter
 805                                            * is also expected to call scsi_free
 806                                            * to release this memory.  (The memory
 807                                            * obtained by scsi_malloc is guaranteed
 808                                            * to be at an address < 16Mb). */
 809
 810         int result;             /* Status code from lower level driver */
 811
 812         unsigned char tag;      /* SCSI-II queued command tag */
 813         unsigned long pid;      /* Process ID, starts at 0 */
 814 };
 815
 816 /*
 817  *  Flag bit for the internal_timeout array
 818  */
 819 #define NORMAL_TIMEOUT 0
 820
 821 /*
 822  * Definitions and prototypes used for scsi mid-level queue.
 823  */
 824 #define SCSI_MLQUEUE_HOST_BUSY   0x1055
 825 #define SCSI_MLQUEUE_DEVICE_BUSY 0x1056
 826
 827 #define SCSI_SLEEP(QUEUE, CONDITION) {              \
 828     if (CONDITION) {                                \
 829         DECLARE_WAITQUEUE(wait, current);           \
 830         add_wait_queue(QUEUE, &wait);               \
 831         for(;;) {                                   \
 832         set_current_state(TASK_UNINTERRUPTIBLE);    \
 833         if (CONDITION) {                            \
 834             if (in_interrupt())                     \
 835                 panic("scsi: trying to call schedule() in interrupt" \
 836                       ", file %s, line %d.\n", __FILE__, __LINE__);  \
 837             schedule();                 \
 838         }                               \
 839         else                            \
 840             break;                      \
 841         }                               \
 842         remove_wait_queue(QUEUE, &wait);\
 843         current->state = TASK_RUNNING;  \
 844     }; }
 845
 846 #endif
 847
 848 /*
 849  * Overrides for Emacs so that we follow Linus's tabbing style.
 850  * Emacs will notice this stuff at the end of the file and automatically
 851  * adjust the settings for this buffer only.  This must remain at the end
 852  * of the file.
 853  * ---------------------------------------------------------------------------
 854  * Local variables:
 855  * c-indent-level: 4
 856  * c-brace-imaginary-offset: 0
 857  * c-brace-offset: -4
 858  * c-argdecl-indent: 4
 859  * c-label-offset: -4
 860  * c-continued-statement-offset: 4
 861  * c-continued-brace-offset: 0
 862  * indent-tabs-mode: nil
 863  * tab-width: 8
 864  * End:
 865  */