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_do_cmd(Scsi_Cmnd *, const void *cmnd,
 497                         void *buffer, unsigned bufflen,
 498                         void (*done) (struct scsi_cmnd *),
 499                         int timeout, int retries);
 500 extern int scsi_dev_init(void);
 501
 502 /*
 503  * Newer request-based interfaces.
 504  */
 505 extern Scsi_Request *scsi_allocate_request(Scsi_Device *);
 506 extern void scsi_release_request(Scsi_Request *);
 507 extern void scsi_wait_req(Scsi_Request *, const void *cmnd,
 508                           void *buffer, unsigned bufflen,
 509                           int timeout, int retries);
 510
 511 extern void scsi_do_req(Scsi_Request *, const void *cmnd,
 512                         void *buffer, unsigned bufflen,
 513                         void (*done) (struct scsi_cmnd *),
 514                         int timeout, int retries);
 515 extern int scsi_insert_special_req(Scsi_Request * SRpnt, int);
 516 extern void scsi_init_cmd_from_req(Scsi_Cmnd *, Scsi_Request *);
 517
 518
 519 /*
 520  * Prototypes for functions/data in hosts.c
 521  */
 522 extern int max_scsi_hosts;
 523
 524 /*
 525  * Prototypes for functions in scsi_proc.c
 526  */
 527 extern void proc_print_scsidevice(Scsi_Device *, char *, int *, int);
 528 extern struct proc_dir_entry *proc_scsi;
 529
 530 /*
 531  * Prototypes for functions in constants.c
 532  */
 533 extern void print_command(unsigned char *);
 534 extern void print_sense(const char *, Scsi_Cmnd *);
 535 extern void print_req_sense(const char *, Scsi_Request *);
 536 extern void print_driverbyte(int scsiresult);
 537 extern void print_hostbyte(int scsiresult);
 538 extern void print_status (int status);
 539
 540 /*
 541  *  The scsi_device struct contains what we know about each given scsi
 542  *  device.
 543  *
 544  * FIXME(eric) - one of the great regrets that I have is that I failed to define
 545  * these structure elements as something like sdev_foo instead of foo.  This would
 546  * make it so much easier to grep through sources and so forth.  I propose that
 547  * all new elements that get added to these structures follow this convention.
 548  * As time goes on and as people have the stomach for it, it should be possible to
 549  * go back and retrofit at least some of the elements here with with the prefix.
 550  */
 551
 552 struct scsi_device {
 553 /* private: */
 554         /*
 555          * This information is private to the scsi mid-layer.  Wrapping it in a
 556          * struct private is a way of marking it in a sort of C++ type of way.
 557          */
 558         struct scsi_device *next;       /* Used for linked list */
 559         struct scsi_device *prev;       /* Used for linked list */
 560         wait_queue_head_t   scpnt_wait; /* Used to wait if
 561                                            device is busy */
 562         struct Scsi_Host *host;
 563         request_queue_t request_queue;
 564         atomic_t                device_active; /* commands checked out for device */
 565         volatile unsigned short device_busy;    /* commands actually active on low-level */
 566         int (*scsi_init_io_fn) (Scsi_Cmnd *);   /* Used to initialize
 567                                                    new request */
 568         Scsi_Cmnd *device_queue;        /* queue of SCSI Command structures */
 569
 570 /* public: */
 571         unsigned int id, lun, channel;
 572
 573         unsigned int manufacturer;      /* Manufacturer of device, for using
 574                                          * vendor-specific cmd's */
 575         unsigned sector_size;   /* size in bytes */
 576
 577         int attached;           /* # of high level drivers attached to
 578                                  * this */
 579         int access_count;       /* Count of open channels/mounts */
 580
 581         void *hostdata;         /* available to low-level driver */
 582         devfs_handle_t de;      /* directory for the device      */
 583         char type;
 584         char scsi_level;
 585         char vendor[8], model[16], rev[4];
 586         unsigned char current_tag;      /* current tag */
 587         unsigned char sync_min_period;  /* Not less than this period */
 588         unsigned char sync_max_offset;  /* Not greater than this offset */
 589         unsigned char queue_depth;      /* How deep a queue to use */
 590
 591         unsigned online:1;
 592         unsigned writeable:1;
 593         unsigned removable:1;
 594         unsigned random:1;
 595         unsigned has_cmdblocks:1;
 596         unsigned changed:1;     /* Data invalid due to media change */
 597         unsigned busy:1;        /* Used to prevent races */
 598         unsigned lockable:1;    /* Able to prevent media removal */
 599         unsigned borken:1;      /* Tell the Seagate driver to be
 600                                  * painfully slow on this device */
 601         unsigned tagged_supported:1;    /* Supports SCSI-II tagged queuing */
 602         unsigned tagged_queue:1;        /* SCSI-II tagged queuing enabled */
 603         unsigned disconnect:1;  /* can disconnect */
 604         unsigned soft_reset:1;  /* Uses soft reset option */
 605         unsigned sync:1;        /* Negotiate for sync transfers */
 606         unsigned wide:1;        /* Negotiate for WIDE transfers */
 607         unsigned single_lun:1;  /* Indicates we should only allow I/O to
 608                                  * one of the luns for the device at a
 609                                  * time. */
 610         unsigned was_reset:1;   /* There was a bus reset on the bus for
 611                                  * this device */
 612         unsigned expecting_cc_ua:1;     /* Expecting a CHECK_CONDITION/UNIT_ATTN
 613                                          * because we did a bus reset. */
 614         unsigned device_blocked:1;      /* Device returned QUEUE_FULL. */
 615         unsigned ten:1;         /* support ten byte read / write */
 616         unsigned remap:1;       /* support remapping  */
 617         unsigned starved:1;     /* unable to process commands because
 618                                    host busy */
 619 };
 620
 621
 622 /*
 623  * The Scsi_Cmnd structure is used by scsi.c internally, and for communication
 624  * with low level drivers that support multiple outstanding commands.
 625  */
 626 typedef struct scsi_pointer {
 627         char *ptr;              /* data pointer */
 628         int this_residual;      /* left in this buffer */
 629         struct scatterlist *buffer;     /* which buffer */
 630         int buffers_residual;   /* how many buffers left */
 631
 632         volatile int Status;
 633         volatile int Message;
 634         volatile int have_data_in;
 635         volatile int sent_command;
 636         volatile int phase;
 637 } Scsi_Pointer;
 638
 639 /*
 640  * This is essentially a slimmed down version of Scsi_Cmnd.  The point of
 641  * having this is that requests that are injected into the queue as result
 642  * of things like ioctls and character devices shouldn't be using a
 643  * Scsi_Cmnd until such a time that the command is actually at the head
 644  * of the queue and being sent to the driver.
 645  */
 646 struct scsi_request {
 647         int     sr_magic;
 648         int     sr_result;      /* Status code from lower level driver */
 649         unsigned char sr_sense_buffer[SCSI_SENSE_BUFFERSIZE];           /* obtained by REQUEST SENSE
 650                                                  * when CHECK CONDITION is
 651                                                  * received on original command
 652                                                  * (auto-sense) */
 653
 654         struct Scsi_Host *sr_host;
 655         Scsi_Device *sr_device;
 656         Scsi_Cmnd *sr_command;
 657         struct request sr_request;      /* A copy of the command we are
 658                                    working on */
 659         unsigned sr_bufflen;    /* Size of data buffer */
 660         void *sr_buffer;                /* Data buffer */
 661         int sr_allowed;
 662         unsigned char sr_data_direction;
 663         unsigned char sr_cmd_len;
 664         unsigned char sr_cmnd[MAX_COMMAND_SIZE];
 665         void (*sr_done) (struct scsi_cmnd *);   /* Mid-level done function */
 666         int sr_timeout_per_command;
 667         unsigned short sr_use_sg;       /* Number of pieces of scatter-gather */
 668         unsigned short sr_sglist_len;   /* size of malloc'd scatter-gather list */
 669         unsigned sr_underflow;  /* Return error if less than
 670                                    this amount is transfered */
 671 };
 672
 673 /*
 674  * FIXME(eric) - one of the great regrets that I have is that I failed to define
 675  * these structure elements as something like sc_foo instead of foo.  This would
 676  * make it so much easier to grep through sources and so forth.  I propose that
 677  * all new elements that get added to these structures follow this convention.
 678  * As time goes on and as people have the stomach for it, it should be possible to
 679  * go back and retrofit at least some of the elements here with with the prefix.
 680  */
 681 struct scsi_cmnd {
 682         int     sc_magic;
 683 /* private: */
 684         /*
 685          * This information is private to the scsi mid-layer.  Wrapping it in a
 686          * struct private is a way of marking it in a sort of C++ type of way.
 687          */
 688         struct Scsi_Host *host;
 689         unsigned short state;
 690         unsigned short owner;
 691         Scsi_Device *device;
 692         Scsi_Request *sc_request;
 693         struct scsi_cmnd *next;
 694         struct scsi_cmnd *reset_chain;
 695
 696         int eh_state;           /* Used for state tracking in error handlr */
 697         void (*done) (struct scsi_cmnd *);      /* Mid-level done function */
 698         /*
 699            A SCSI Command is assigned a nonzero serial_number when internal_cmnd
 700            passes it to the driver's queue command function.  The serial_number
 701            is cleared when scsi_done is entered indicating that the command has
 702            been completed.  If a timeout occurs, the serial number at the moment
 703            of timeout is copied into serial_number_at_timeout.  By subsequently
 704            comparing the serial_number and serial_number_at_timeout fields
 705            during abort or reset processing, we can detect whether the command
 706            has already completed.  This also detects cases where the command has
 707            completed and the SCSI Command structure has already being reused
 708            for another command, so that we can avoid incorrectly aborting or
 709            resetting the new command.
 710          */
 711
 712         unsigned long serial_number;
 713         unsigned long serial_number_at_timeout;
 714
 715         int retries;
 716         int allowed;
 717         int timeout_per_command;
 718         int timeout_total;
 719         int timeout;
 720
 721         /*
 722          * We handle the timeout differently if it happens when a reset,
 723          * abort, etc are in process.
 724          */
 725         unsigned volatile char internal_timeout;
 726         struct scsi_cmnd *bh_next;      /* To enumerate the commands waiting
 727                                            to be processed. */
 728
 729 /* public: */
 730
 731         unsigned int target;
 732         unsigned int lun;
 733         unsigned int channel;
 734         unsigned char cmd_len;
 735         unsigned char old_cmd_len;
 736         unsigned char sc_data_direction;
 737         unsigned char sc_old_data_direction;
 738
 739         /* These elements define the operation we are about to perform */
 740         unsigned char cmnd[MAX_COMMAND_SIZE];
 741         unsigned request_bufflen;       /* Actual request size */
 742
 743         struct timer_list eh_timeout;   /* Used to time out the command. */
 744         void *request_buffer;   /* Actual requested buffer */
 745
 746         /* These elements define the operation we ultimately want to perform */
 747         unsigned char data_cmnd[MAX_COMMAND_SIZE];
 748         unsigned short old_use_sg;      /* We save  use_sg here when requesting
 749                                          * sense info */
 750         unsigned short use_sg;  /* Number of pieces of scatter-gather */
 751         unsigned short sglist_len;      /* size of malloc'd scatter-gather list */
 752         unsigned short abort_reason;    /* If the mid-level code requests an
 753                                          * abort, this is the reason. */
 754         unsigned bufflen;       /* Size of data buffer */
 755         void *buffer;           /* Data buffer */
 756
 757         unsigned underflow;     /* Return error if less than
 758                                    this amount is transfered */
 759         unsigned old_underflow; /* save underflow here when reusing the
 760                                  * command for error handling */
 761
 762         unsigned transfersize;  /* How much we are guaranteed to
 763                                    transfer with each SCSI transfer
 764                                    (ie, between disconnect /
 765                                    reconnects.   Probably == sector
 766                                    size */
 767
 768         int resid;              /* Number of bytes requested to be
 769                                    transferred less actual number
 770                                    transferred (0 if not supported) */
 771
 772         struct request request; /* A copy of the command we are
 773                                    working on */
 774
 775         unsigned char sense_buffer[SCSI_SENSE_BUFFERSIZE];              /* obtained by REQUEST SENSE
 776                                                  * when CHECK CONDITION is
 777                                                  * received on original command
 778                                                  * (auto-sense) */
 779
 780         unsigned flags;
 781
 782         /*
 783          * Used to indicate that a command which has timed out also
 784          * completed normally.  Typically the completion function will
 785          * do nothing but set this flag in this instance because the
 786          * timeout handler is already running.
 787          */
 788         unsigned done_late:1;
 789
 790         /* Low-level done function - can be used by low-level driver to point
 791          *        to completion function.  Not used by mid/upper level code. */
 792         void (*scsi_done) (struct scsi_cmnd *);
 793
 794         /*
 795          * The following fields can be written to by the host specific code.
 796          * Everything else should be left alone.
 797          */
 798
 799         Scsi_Pointer SCp;       /* Scratchpad used by some host adapters */
 800
 801         unsigned char *host_scribble;   /* The host adapter is allowed to
 802                                            * call scsi_malloc and get some memory
 803                                            * and hang it here.     The host adapter
 804                                            * is also expected to call scsi_free
 805                                            * to release this memory.  (The memory
 806                                            * obtained by scsi_malloc is guaranteed
 807                                            * to be at an address < 16Mb). */
 808
 809         int result;             /* Status code from lower level driver */
 810
 811         unsigned char tag;      /* SCSI-II queued command tag */
 812         unsigned long pid;      /* Process ID, starts at 0 */
 813 };
 814
 815 /*
 816  *  Flag bit for the internal_timeout array
 817  */
 818 #define NORMAL_TIMEOUT 0
 819
 820 /*
 821  * Definitions and prototypes used for scsi mid-level queue.
 822  */
 823 #define SCSI_MLQUEUE_HOST_BUSY   0x1055
 824 #define SCSI_MLQUEUE_DEVICE_BUSY 0x1056
 825
 826 #define SCSI_SLEEP(QUEUE, CONDITION) {              \
 827     if (CONDITION) {                                \
 828         DECLARE_WAITQUEUE(wait, current);           \
 829         add_wait_queue(QUEUE, &wait);               \
 830         for(;;) {                                   \
 831         set_current_state(TASK_UNINTERRUPTIBLE);    \
 832         if (CONDITION) {                            \
 833             if (in_interrupt())                     \
 834                 panic("scsi: trying to call schedule() in interrupt" \
 835                       ", file %s, line %d.\n", __FILE__, __LINE__);  \
 836             schedule();                 \
 837         }                               \
 838         else                            \
 839             break;                      \
 840         }                               \
 841         remove_wait_queue(QUEUE, &wait);\
 842         current->state = TASK_RUNNING;  \
 843     }; }
 844
 845 #endif
 846
 847 /*
 848  * Overrides for Emacs so that we follow Linus's tabbing style.
 849  * Emacs will notice this stuff at the end of the file and automatically
 850  * adjust the settings for this buffer only.  This must remain at the end
 851  * of the file.
 852  * ---------------------------------------------------------------------------
 853  * Local variables:
 854  * c-indent-level: 4
 855  * c-brace-imaginary-offset: 0
 856  * c-brace-offset: -4
 857  * c-argdecl-indent: 4
 858  * c-label-offset: -4
 859  * c-continued-statement-offset: 4
 860  * c-continued-brace-offset: 0
 861  * indent-tabs-mode: nil
 862  * tab-width: 8
 863  * End:
 864  */