linux/include/scsi/scsi_host.h
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   1#ifndef _SCSI_SCSI_HOST_H
   2#define _SCSI_SCSI_HOST_H
   3
   4#include <linux/device.h>
   5#include <linux/list.h>
   6#include <linux/types.h>
   7#include <linux/workqueue.h>
   8#include <linux/mutex.h>
   9#include <scsi/scsi.h>
  10
  11struct request_queue;
  12struct block_device;
  13struct completion;
  14struct module;
  15struct scsi_cmnd;
  16struct scsi_device;
  17struct scsi_target;
  18struct Scsi_Host;
  19struct scsi_host_cmd_pool;
  20struct scsi_transport_template;
  21struct blk_queue_tags;
  22
  23
  24/*
  25 * The various choices mean:
  26 * NONE: Self evident.  Host adapter is not capable of scatter-gather.
  27 * ALL:  Means that the host adapter module can do scatter-gather,
  28 *       and that there is no limit to the size of the table to which
  29 *       we scatter/gather data.  The value we set here is the maximum
  30 *       single element sglist.  To use chained sglists, the adapter
  31 *       has to set a value beyond ALL (and correctly use the chain
  32 *       handling API.
  33 * Anything else:  Indicates the maximum number of chains that can be
  34 *       used in one scatter-gather request.
  35 */
  36#define SG_NONE 0
  37#define SG_ALL  SCSI_MAX_SG_SEGMENTS
  38
  39#define MODE_UNKNOWN 0x00
  40#define MODE_INITIATOR 0x01
  41#define MODE_TARGET 0x02
  42
  43#define DISABLE_CLUSTERING 0
  44#define ENABLE_CLUSTERING 1
  45
  46enum {
  47        SCSI_QDEPTH_DEFAULT,    /* default requested change, e.g. from sysfs */
  48        SCSI_QDEPTH_QFULL,      /* scsi-ml requested due to queue full */
  49        SCSI_QDEPTH_RAMP_UP,    /* scsi-ml requested due to threshhold event */
  50};
  51
  52struct scsi_host_template {
  53        struct module *module;
  54        const char *name;
  55
  56        /*
  57         * Used to initialize old-style drivers.  For new-style drivers
  58         * just perform all work in your module initialization function.
  59         *
  60         * Status:  OBSOLETE
  61         */
  62        int (* detect)(struct scsi_host_template *);
  63
  64        /*
  65         * Used as unload callback for hosts with old-style drivers.
  66         *
  67         * Status: OBSOLETE
  68         */
  69        int (* release)(struct Scsi_Host *);
  70
  71        /*
  72         * The info function will return whatever useful information the
  73         * developer sees fit.  If not provided, then the name field will
  74         * be used instead.
  75         *
  76         * Status: OPTIONAL
  77         */
  78        const char *(* info)(struct Scsi_Host *);
  79
  80        /*
  81         * Ioctl interface
  82         *
  83         * Status: OPTIONAL
  84         */
  85        int (* ioctl)(struct scsi_device *dev, int cmd, void __user *arg);
  86
  87
  88#ifdef CONFIG_COMPAT
  89        /* 
  90         * Compat handler. Handle 32bit ABI.
  91         * When unknown ioctl is passed return -ENOIOCTLCMD.
  92         *
  93         * Status: OPTIONAL
  94         */
  95        int (* compat_ioctl)(struct scsi_device *dev, int cmd, void __user *arg);
  96#endif
  97
  98        /*
  99         * The queuecommand function is used to queue up a scsi
 100         * command block to the LLDD.  When the driver finished
 101         * processing the command the done callback is invoked.
 102         *
 103         * If queuecommand returns 0, then the HBA has accepted the
 104         * command.  The done() function must be called on the command
 105         * when the driver has finished with it. (you may call done on the
 106         * command before queuecommand returns, but in this case you
 107         * *must* return 0 from queuecommand).
 108         *
 109         * Queuecommand may also reject the command, in which case it may
 110         * not touch the command and must not call done() for it.
 111         *
 112         * There are two possible rejection returns:
 113         *
 114         *   SCSI_MLQUEUE_DEVICE_BUSY: Block this device temporarily, but
 115         *   allow commands to other devices serviced by this host.
 116         *
 117         *   SCSI_MLQUEUE_HOST_BUSY: Block all devices served by this
 118         *   host temporarily.
 119         *
 120         * For compatibility, any other non-zero return is treated the
 121         * same as SCSI_MLQUEUE_HOST_BUSY.
 122         *
 123         * NOTE: "temporarily" means either until the next command for#
 124         * this device/host completes, or a period of time determined by
 125         * I/O pressure in the system if there are no other outstanding
 126         * commands.
 127         *
 128         * STATUS: REQUIRED
 129         */
 130        int (* queuecommand)(struct Scsi_Host *, struct scsi_cmnd *);
 131
 132        /*
 133         * The transfer functions are used to queue a scsi command to
 134         * the LLD. When the driver is finished processing the command
 135         * the done callback is invoked.
 136         *
 137         * This is called to inform the LLD to transfer
 138         * scsi_bufflen(cmd) bytes. scsi_sg_count(cmd) speciefies the
 139         * number of scatterlist entried in the command and
 140         * scsi_sglist(cmd) returns the scatterlist.
 141         *
 142         * return values: see queuecommand
 143         *
 144         * If the LLD accepts the cmd, it should set the result to an
 145         * appropriate value when completed before calling the done function.
 146         *
 147         * STATUS: REQUIRED FOR TARGET DRIVERS
 148         */
 149        /* TODO: rename */
 150        int (* transfer_response)(struct scsi_cmnd *,
 151                                  void (*done)(struct scsi_cmnd *));
 152
 153        /*
 154         * This is an error handling strategy routine.  You don't need to
 155         * define one of these if you don't want to - there is a default
 156         * routine that is present that should work in most cases.  For those
 157         * driver authors that have the inclination and ability to write their
 158         * own strategy routine, this is where it is specified.  Note - the
 159         * strategy routine is *ALWAYS* run in the context of the kernel eh
 160         * thread.  Thus you are guaranteed to *NOT* be in an interrupt
 161         * handler when you execute this, and you are also guaranteed to
 162         * *NOT* have any other commands being queued while you are in the
 163         * strategy routine. When you return from this function, operations
 164         * return to normal.
 165         *
 166         * See scsi_error.c scsi_unjam_host for additional comments about
 167         * what this function should and should not be attempting to do.
 168         *
 169         * Status: REQUIRED     (at least one of them)
 170         */
 171        int (* eh_abort_handler)(struct scsi_cmnd *);
 172        int (* eh_device_reset_handler)(struct scsi_cmnd *);
 173        int (* eh_target_reset_handler)(struct scsi_cmnd *);
 174        int (* eh_bus_reset_handler)(struct scsi_cmnd *);
 175        int (* eh_host_reset_handler)(struct scsi_cmnd *);
 176
 177        /*
 178         * Before the mid layer attempts to scan for a new device where none
 179         * currently exists, it will call this entry in your driver.  Should
 180         * your driver need to allocate any structs or perform any other init
 181         * items in order to send commands to a currently unused target/lun
 182         * combo, then this is where you can perform those allocations.  This
 183         * is specifically so that drivers won't have to perform any kind of
 184         * "is this a new device" checks in their queuecommand routine,
 185         * thereby making the hot path a bit quicker.
 186         *
 187         * Return values: 0 on success, non-0 on failure
 188         *
 189         * Deallocation:  If we didn't find any devices at this ID, you will
 190         * get an immediate call to slave_destroy().  If we find something
 191         * here then you will get a call to slave_configure(), then the
 192         * device will be used for however long it is kept around, then when
 193         * the device is removed from the system (or * possibly at reboot
 194         * time), you will then get a call to slave_destroy().  This is
 195         * assuming you implement slave_configure and slave_destroy.
 196         * However, if you allocate memory and hang it off the device struct,
 197         * then you must implement the slave_destroy() routine at a minimum
 198         * in order to avoid leaking memory
 199         * each time a device is tore down.
 200         *
 201         * Status: OPTIONAL
 202         */
 203        int (* slave_alloc)(struct scsi_device *);
 204
 205        /*
 206         * Once the device has responded to an INQUIRY and we know the
 207         * device is online, we call into the low level driver with the
 208         * struct scsi_device *.  If the low level device driver implements
 209         * this function, it *must* perform the task of setting the queue
 210         * depth on the device.  All other tasks are optional and depend
 211         * on what the driver supports and various implementation details.
 212         * 
 213         * Things currently recommended to be handled at this time include:
 214         *
 215         * 1.  Setting the device queue depth.  Proper setting of this is
 216         *     described in the comments for scsi_adjust_queue_depth.
 217         * 2.  Determining if the device supports the various synchronous
 218         *     negotiation protocols.  The device struct will already have
 219         *     responded to INQUIRY and the results of the standard items
 220         *     will have been shoved into the various device flag bits, eg.
 221         *     device->sdtr will be true if the device supports SDTR messages.
 222         * 3.  Allocating command structs that the device will need.
 223         * 4.  Setting the default timeout on this device (if needed).
 224         * 5.  Anything else the low level driver might want to do on a device
 225         *     specific setup basis...
 226         * 6.  Return 0 on success, non-0 on error.  The device will be marked
 227         *     as offline on error so that no access will occur.  If you return
 228         *     non-0, your slave_destroy routine will never get called for this
 229         *     device, so don't leave any loose memory hanging around, clean
 230         *     up after yourself before returning non-0
 231         *
 232         * Status: OPTIONAL
 233         */
 234        int (* slave_configure)(struct scsi_device *);
 235
 236        /*
 237         * Immediately prior to deallocating the device and after all activity
 238         * has ceased the mid layer calls this point so that the low level
 239         * driver may completely detach itself from the scsi device and vice
 240         * versa.  The low level driver is responsible for freeing any memory
 241         * it allocated in the slave_alloc or slave_configure calls. 
 242         *
 243         * Status: OPTIONAL
 244         */
 245        void (* slave_destroy)(struct scsi_device *);
 246
 247        /*
 248         * Before the mid layer attempts to scan for a new device attached
 249         * to a target where no target currently exists, it will call this
 250         * entry in your driver.  Should your driver need to allocate any
 251         * structs or perform any other init items in order to send commands
 252         * to a currently unused target, then this is where you can perform
 253         * those allocations.
 254         *
 255         * Return values: 0 on success, non-0 on failure
 256         *
 257         * Status: OPTIONAL
 258         */
 259        int (* target_alloc)(struct scsi_target *);
 260
 261        /*
 262         * Immediately prior to deallocating the target structure, and
 263         * after all activity to attached scsi devices has ceased, the
 264         * midlayer calls this point so that the driver may deallocate
 265         * and terminate any references to the target.
 266         *
 267         * Status: OPTIONAL
 268         */
 269        void (* target_destroy)(struct scsi_target *);
 270
 271        /*
 272         * If a host has the ability to discover targets on its own instead
 273         * of scanning the entire bus, it can fill in this function and
 274         * call scsi_scan_host().  This function will be called periodically
 275         * until it returns 1 with the scsi_host and the elapsed time of
 276         * the scan in jiffies.
 277         *
 278         * Status: OPTIONAL
 279         */
 280        int (* scan_finished)(struct Scsi_Host *, unsigned long);
 281
 282        /*
 283         * If the host wants to be called before the scan starts, but
 284         * after the midlayer has set up ready for the scan, it can fill
 285         * in this function.
 286         *
 287         * Status: OPTIONAL
 288         */
 289        void (* scan_start)(struct Scsi_Host *);
 290
 291        /*
 292         * Fill in this function to allow the queue depth of this host
 293         * to be changeable (on a per device basis).  Returns either
 294         * the current queue depth setting (may be different from what
 295         * was passed in) or an error.  An error should only be
 296         * returned if the requested depth is legal but the driver was
 297         * unable to set it.  If the requested depth is illegal, the
 298         * driver should set and return the closest legal queue depth.
 299         *
 300         * Status: OPTIONAL
 301         */
 302        int (* change_queue_depth)(struct scsi_device *, int, int);
 303
 304        /*
 305         * Fill in this function to allow the changing of tag types
 306         * (this also allows the enabling/disabling of tag command
 307         * queueing).  An error should only be returned if something
 308         * went wrong in the driver while trying to set the tag type.
 309         * If the driver doesn't support the requested tag type, then
 310         * it should set the closest type it does support without
 311         * returning an error.  Returns the actual tag type set.
 312         *
 313         * Status: OPTIONAL
 314         */
 315        int (* change_queue_type)(struct scsi_device *, int);
 316
 317        /*
 318         * This function determines the BIOS parameters for a given
 319         * harddisk.  These tend to be numbers that are made up by
 320         * the host adapter.  Parameters:
 321         * size, device, list (heads, sectors, cylinders)
 322         *
 323         * Status: OPTIONAL
 324         */
 325        int (* bios_param)(struct scsi_device *, struct block_device *,
 326                        sector_t, int []);
 327
 328        /*
 329         * This function is called when one or more partitions on the
 330         * device reach beyond the end of the device.
 331         *
 332         * Status: OPTIONAL
 333         */
 334        void (*unlock_native_capacity)(struct scsi_device *);
 335
 336        /*
 337         * Can be used to export driver statistics and other infos to the
 338         * world outside the kernel ie. userspace and it also provides an
 339         * interface to feed the driver with information.
 340         *
 341         * Status: OBSOLETE
 342         */
 343        int (*proc_info)(struct Scsi_Host *, char *, char **, off_t, int, int);
 344
 345        /*
 346         * This is an optional routine that allows the transport to become
 347         * involved when a scsi io timer fires. The return value tells the
 348         * timer routine how to finish the io timeout handling:
 349         * EH_HANDLED:          I fixed the error, please complete the command
 350         * EH_RESET_TIMER:      I need more time, reset the timer and
 351         *                      begin counting again
 352         * EH_NOT_HANDLED       Begin normal error recovery
 353         *
 354         * Status: OPTIONAL
 355         */
 356        enum blk_eh_timer_return (*eh_timed_out)(struct scsi_cmnd *);
 357
 358        /*
 359         * Name of proc directory
 360         */
 361        const char *proc_name;
 362
 363        /*
 364         * Used to store the procfs directory if a driver implements the
 365         * proc_info method.
 366         */
 367        struct proc_dir_entry *proc_dir;
 368
 369        /*
 370         * This determines if we will use a non-interrupt driven
 371         * or an interrupt driven scheme.  It is set to the maximum number
 372         * of simultaneous commands a given host adapter will accept.
 373         */
 374        int can_queue;
 375
 376        /*
 377         * In many instances, especially where disconnect / reconnect are
 378         * supported, our host also has an ID on the SCSI bus.  If this is
 379         * the case, then it must be reserved.  Please set this_id to -1 if
 380         * your setup is in single initiator mode, and the host lacks an
 381         * ID.
 382         */
 383        int this_id;
 384
 385        /*
 386         * This determines the degree to which the host adapter is capable
 387         * of scatter-gather.
 388         */
 389        unsigned short sg_tablesize;
 390        unsigned short sg_prot_tablesize;
 391
 392        /*
 393         * Set this if the host adapter has limitations beside segment count.
 394         */
 395        unsigned short max_sectors;
 396
 397        /*
 398         * DMA scatter gather segment boundary limit. A segment crossing this
 399         * boundary will be split in two.
 400         */
 401        unsigned long dma_boundary;
 402
 403        /*
 404         * This specifies "machine infinity" for host templates which don't
 405         * limit the transfer size.  Note this limit represents an absolute
 406         * maximum, and may be over the transfer limits allowed for
 407         * individual devices (e.g. 256 for SCSI-1).
 408         */
 409#define SCSI_DEFAULT_MAX_SECTORS        1024
 410
 411        /*
 412         * True if this host adapter can make good use of linked commands.
 413         * This will allow more than one command to be queued to a given
 414         * unit on a given host.  Set this to the maximum number of command
 415         * blocks to be provided for each device.  Set this to 1 for one
 416         * command block per lun, 2 for two, etc.  Do not set this to 0.
 417         * You should make sure that the host adapter will do the right thing
 418         * before you try setting this above 1.
 419         */
 420        short cmd_per_lun;
 421
 422        /*
 423         * present contains counter indicating how many boards of this
 424         * type were found when we did the scan.
 425         */
 426        unsigned char present;
 427
 428        /*
 429         * This specifies the mode that a LLD supports.
 430         */
 431        unsigned supported_mode:2;
 432
 433        /*
 434         * True if this host adapter uses unchecked DMA onto an ISA bus.
 435         */
 436        unsigned unchecked_isa_dma:1;
 437
 438        /*
 439         * True if this host adapter can make good use of clustering.
 440         * I originally thought that if the tablesize was large that it
 441         * was a waste of CPU cycles to prepare a cluster list, but
 442         * it works out that the Buslogic is faster if you use a smaller
 443         * number of segments (i.e. use clustering).  I guess it is
 444         * inefficient.
 445         */
 446        unsigned use_clustering:1;
 447
 448        /*
 449         * True for emulated SCSI host adapters (e.g. ATAPI).
 450         */
 451        unsigned emulated:1;
 452
 453        /*
 454         * True if the low-level driver performs its own reset-settle delays.
 455         */
 456        unsigned skip_settle_delay:1;
 457
 458        /*
 459         * True if we are using ordered write support.
 460         */
 461        unsigned ordered_tag:1;
 462
 463        /*
 464         * Countdown for host blocking with no commands outstanding.
 465         */
 466        unsigned int max_host_blocked;
 467
 468        /*
 469         * Default value for the blocking.  If the queue is empty,
 470         * host_blocked counts down in the request_fn until it restarts
 471         * host operations as zero is reached.  
 472         *
 473         * FIXME: This should probably be a value in the template
 474         */
 475#define SCSI_DEFAULT_HOST_BLOCKED       7
 476
 477        /*
 478         * Pointer to the sysfs class properties for this host, NULL terminated.
 479         */
 480        struct device_attribute **shost_attrs;
 481
 482        /*
 483         * Pointer to the SCSI device properties for this host, NULL terminated.
 484         */
 485        struct device_attribute **sdev_attrs;
 486
 487        /*
 488         * List of hosts per template.
 489         *
 490         * This is only for use by scsi_module.c for legacy templates.
 491         * For these access to it is synchronized implicitly by
 492         * module_init/module_exit.
 493         */
 494        struct list_head legacy_hosts;
 495
 496        /*
 497         * Vendor Identifier associated with the host
 498         *
 499         * Note: When specifying vendor_id, be sure to read the
 500         *   Vendor Type and ID formatting requirements specified in
 501         *   scsi_netlink.h
 502         */
 503        u64 vendor_id;
 504};
 505
 506/*
 507 * Temporary #define for host lock push down. Can be removed when all
 508 * drivers have been updated to take advantage of unlocked
 509 * queuecommand.
 510 *
 511 */
 512#define DEF_SCSI_QCMD(func_name) \
 513        int func_name(struct Scsi_Host *shost, struct scsi_cmnd *cmd)   \
 514        {                                                               \
 515                unsigned long irq_flags;                                \
 516                int rc;                                                 \
 517                spin_lock_irqsave(shost->host_lock, irq_flags);         \
 518                scsi_cmd_get_serial(shost, cmd);                        \
 519                rc = func_name##_lck (cmd, cmd->scsi_done);                     \
 520                spin_unlock_irqrestore(shost->host_lock, irq_flags);    \
 521                return rc;                                              \
 522        }
 523
 524
 525/*
 526 * shost state: If you alter this, you also need to alter scsi_sysfs.c
 527 * (for the ascii descriptions) and the state model enforcer:
 528 * scsi_host_set_state()
 529 */
 530enum scsi_host_state {
 531        SHOST_CREATED = 1,
 532        SHOST_RUNNING,
 533        SHOST_CANCEL,
 534        SHOST_DEL,
 535        SHOST_RECOVERY,
 536        SHOST_CANCEL_RECOVERY,
 537        SHOST_DEL_RECOVERY,
 538};
 539
 540struct Scsi_Host {
 541        /*
 542         * __devices is protected by the host_lock, but you should
 543         * usually use scsi_device_lookup / shost_for_each_device
 544         * to access it and don't care about locking yourself.
 545         * In the rare case of beeing in irq context you can use
 546         * their __ prefixed variants with the lock held. NEVER
 547         * access this list directly from a driver.
 548         */
 549        struct list_head        __devices;
 550        struct list_head        __targets;
 551        
 552        struct scsi_host_cmd_pool *cmd_pool;
 553        spinlock_t              free_list_lock;
 554        struct list_head        free_list; /* backup store of cmd structs */
 555        struct list_head        starved_list;
 556
 557        spinlock_t              default_lock;
 558        spinlock_t              *host_lock;
 559
 560        struct mutex            scan_mutex;/* serialize scanning activity */
 561
 562        struct list_head        eh_cmd_q;
 563        struct task_struct    * ehandler;  /* Error recovery thread. */
 564        struct completion     * eh_action; /* Wait for specific actions on the
 565                                              host. */
 566        wait_queue_head_t       host_wait;
 567        struct scsi_host_template *hostt;
 568        struct scsi_transport_template *transportt;
 569
 570        /*
 571         * Area to keep a shared tag map (if needed, will be
 572         * NULL if not).
 573         */
 574        struct blk_queue_tag    *bqt;
 575
 576        /*
 577         * The following two fields are protected with host_lock;
 578         * however, eh routines can safely access during eh processing
 579         * without acquiring the lock.
 580         */
 581        unsigned int host_busy;            /* commands actually active on low-level */
 582        unsigned int host_failed;          /* commands that failed. */
 583        unsigned int host_eh_scheduled;    /* EH scheduled without command */
 584    
 585        unsigned int host_no;  /* Used for IOCTL_GET_IDLUN, /proc/scsi et al. */
 586        int resetting; /* if set, it means that last_reset is a valid value */
 587        unsigned long last_reset;
 588
 589        /*
 590         * These three parameters can be used to allow for wide scsi,
 591         * and for host adapters that support multiple busses
 592         * The first two should be set to 1 more than the actual max id
 593         * or lun (i.e. 8 for normal systems).
 594         */
 595        unsigned int max_id;
 596        unsigned int max_lun;
 597        unsigned int max_channel;
 598
 599        /*
 600         * This is a unique identifier that must be assigned so that we
 601         * have some way of identifying each detected host adapter properly
 602         * and uniquely.  For hosts that do not support more than one card
 603         * in the system at one time, this does not need to be set.  It is
 604         * initialized to 0 in scsi_register.
 605         */
 606        unsigned int unique_id;
 607
 608        /*
 609         * The maximum length of SCSI commands that this host can accept.
 610         * Probably 12 for most host adapters, but could be 16 for others.
 611         * or 260 if the driver supports variable length cdbs.
 612         * For drivers that don't set this field, a value of 12 is
 613         * assumed.
 614         */
 615        unsigned short max_cmd_len;
 616
 617        int this_id;
 618        int can_queue;
 619        short cmd_per_lun;
 620        short unsigned int sg_tablesize;
 621        short unsigned int sg_prot_tablesize;
 622        short unsigned int max_sectors;
 623        unsigned long dma_boundary;
 624        /* 
 625         * Used to assign serial numbers to the cmds.
 626         * Protected by the host lock.
 627         */
 628        unsigned long cmd_serial_number;
 629        
 630        unsigned active_mode:2;
 631        unsigned unchecked_isa_dma:1;
 632        unsigned use_clustering:1;
 633        unsigned use_blk_tcq:1;
 634
 635        /*
 636         * Host has requested that no further requests come through for the
 637         * time being.
 638         */
 639        unsigned host_self_blocked:1;
 640    
 641        /*
 642         * Host uses correct SCSI ordering not PC ordering. The bit is
 643         * set for the minority of drivers whose authors actually read
 644         * the spec ;).
 645         */
 646        unsigned reverse_ordering:1;
 647
 648        /*
 649         * Ordered write support
 650         */
 651        unsigned ordered_tag:1;
 652
 653        /* Task mgmt function in progress */
 654        unsigned tmf_in_progress:1;
 655
 656        /* Asynchronous scan in progress */
 657        unsigned async_scan:1;
 658
 659        /*
 660         * Optional work queue to be utilized by the transport
 661         */
 662        char work_q_name[20];
 663        struct workqueue_struct *work_q;
 664
 665        /*
 666         * Host has rejected a command because it was busy.
 667         */
 668        unsigned int host_blocked;
 669
 670        /*
 671         * Value host_blocked counts down from
 672         */
 673        unsigned int max_host_blocked;
 674
 675        /* Protection Information */
 676        unsigned int prot_capabilities;
 677        unsigned char prot_guard_type;
 678
 679        /*
 680         * q used for scsi_tgt msgs, async events or any other requests that
 681         * need to be processed in userspace
 682         */
 683        struct request_queue *uspace_req_q;
 684
 685        /* legacy crap */
 686        unsigned long base;
 687        unsigned long io_port;
 688        unsigned char n_io_port;
 689        unsigned char dma_channel;
 690        unsigned int  irq;
 691        
 692
 693        enum scsi_host_state shost_state;
 694
 695        /* ldm bits */
 696        struct device           shost_gendev, shost_dev;
 697
 698        /*
 699         * List of hosts per template.
 700         *
 701         * This is only for use by scsi_module.c for legacy templates.
 702         * For these access to it is synchronized implicitly by
 703         * module_init/module_exit.
 704         */
 705        struct list_head sht_legacy_list;
 706
 707        /*
 708         * Points to the transport data (if any) which is allocated
 709         * separately
 710         */
 711        void *shost_data;
 712
 713        /*
 714         * Points to the physical bus device we'd use to do DMA
 715         * Needed just in case we have virtual hosts.
 716         */
 717        struct device *dma_dev;
 718
 719        /*
 720         * We should ensure that this is aligned, both for better performance
 721         * and also because some compilers (m68k) don't automatically force
 722         * alignment to a long boundary.
 723         */
 724        unsigned long hostdata[0]  /* Used for storage of host specific stuff */
 725                __attribute__ ((aligned (sizeof(unsigned long))));
 726};
 727
 728#define         class_to_shost(d)       \
 729        container_of(d, struct Scsi_Host, shost_dev)
 730
 731#define shost_printk(prefix, shost, fmt, a...)  \
 732        dev_printk(prefix, &(shost)->shost_gendev, fmt, ##a)
 733
 734static inline void *shost_priv(struct Scsi_Host *shost)
 735{
 736        return (void *)shost->hostdata;
 737}
 738
 739int scsi_is_host_device(const struct device *);
 740
 741static inline struct Scsi_Host *dev_to_shost(struct device *dev)
 742{
 743        while (!scsi_is_host_device(dev)) {
 744                if (!dev->parent)
 745                        return NULL;
 746                dev = dev->parent;
 747        }
 748        return container_of(dev, struct Scsi_Host, shost_gendev);
 749}
 750
 751static inline int scsi_host_in_recovery(struct Scsi_Host *shost)
 752{
 753        return shost->shost_state == SHOST_RECOVERY ||
 754                shost->shost_state == SHOST_CANCEL_RECOVERY ||
 755                shost->shost_state == SHOST_DEL_RECOVERY ||
 756                shost->tmf_in_progress;
 757}
 758
 759extern int scsi_queue_work(struct Scsi_Host *, struct work_struct *);
 760extern void scsi_flush_work(struct Scsi_Host *);
 761
 762extern struct Scsi_Host *scsi_host_alloc(struct scsi_host_template *, int);
 763extern int __must_check scsi_add_host_with_dma(struct Scsi_Host *,
 764                                               struct device *,
 765                                               struct device *);
 766extern void scsi_scan_host(struct Scsi_Host *);
 767extern void scsi_rescan_device(struct device *);
 768extern void scsi_remove_host(struct Scsi_Host *);
 769extern struct Scsi_Host *scsi_host_get(struct Scsi_Host *);
 770extern void scsi_host_put(struct Scsi_Host *t);
 771extern struct Scsi_Host *scsi_host_lookup(unsigned short);
 772extern const char *scsi_host_state_name(enum scsi_host_state);
 773extern void scsi_cmd_get_serial(struct Scsi_Host *, struct scsi_cmnd *);
 774
 775extern u64 scsi_calculate_bounce_limit(struct Scsi_Host *);
 776
 777static inline int __must_check scsi_add_host(struct Scsi_Host *host,
 778                                             struct device *dev)
 779{
 780        return scsi_add_host_with_dma(host, dev, dev);
 781}
 782
 783static inline struct device *scsi_get_device(struct Scsi_Host *shost)
 784{
 785        return shost->shost_gendev.parent;
 786}
 787
 788/**
 789 * scsi_host_scan_allowed - Is scanning of this host allowed
 790 * @shost:      Pointer to Scsi_Host.
 791 **/
 792static inline int scsi_host_scan_allowed(struct Scsi_Host *shost)
 793{
 794        return shost->shost_state == SHOST_RUNNING;
 795}
 796
 797extern void scsi_unblock_requests(struct Scsi_Host *);
 798extern void scsi_block_requests(struct Scsi_Host *);
 799
 800struct class_container;
 801
 802extern struct request_queue *__scsi_alloc_queue(struct Scsi_Host *shost,
 803                                                void (*) (struct request_queue *));
 804/*
 805 * These two functions are used to allocate and free a pseudo device
 806 * which will connect to the host adapter itself rather than any
 807 * physical device.  You must deallocate when you are done with the
 808 * thing.  This physical pseudo-device isn't real and won't be available
 809 * from any high-level drivers.
 810 */
 811extern void scsi_free_host_dev(struct scsi_device *);
 812extern struct scsi_device *scsi_get_host_dev(struct Scsi_Host *);
 813
 814/*
 815 * DIF defines the exchange of protection information between
 816 * initiator and SBC block device.
 817 *
 818 * DIX defines the exchange of protection information between OS and
 819 * initiator.
 820 */
 821enum scsi_host_prot_capabilities {
 822        SHOST_DIF_TYPE1_PROTECTION = 1 << 0, /* T10 DIF Type 1 */
 823        SHOST_DIF_TYPE2_PROTECTION = 1 << 1, /* T10 DIF Type 2 */
 824        SHOST_DIF_TYPE3_PROTECTION = 1 << 2, /* T10 DIF Type 3 */
 825
 826        SHOST_DIX_TYPE0_PROTECTION = 1 << 3, /* DIX between OS and HBA only */
 827        SHOST_DIX_TYPE1_PROTECTION = 1 << 4, /* DIX with DIF Type 1 */
 828        SHOST_DIX_TYPE2_PROTECTION = 1 << 5, /* DIX with DIF Type 2 */
 829        SHOST_DIX_TYPE3_PROTECTION = 1 << 6, /* DIX with DIF Type 3 */
 830};
 831
 832/*
 833 * SCSI hosts which support the Data Integrity Extensions must
 834 * indicate their capabilities by setting the prot_capabilities using
 835 * this call.
 836 */
 837static inline void scsi_host_set_prot(struct Scsi_Host *shost, unsigned int mask)
 838{
 839        shost->prot_capabilities = mask;
 840}
 841
 842static inline unsigned int scsi_host_get_prot(struct Scsi_Host *shost)
 843{
 844        return shost->prot_capabilities;
 845}
 846
 847static inline int scsi_host_prot_dma(struct Scsi_Host *shost)
 848{
 849        return shost->prot_capabilities >= SHOST_DIX_TYPE0_PROTECTION;
 850}
 851
 852static inline unsigned int scsi_host_dif_capable(struct Scsi_Host *shost, unsigned int target_type)
 853{
 854        static unsigned char cap[] = { 0,
 855                                       SHOST_DIF_TYPE1_PROTECTION,
 856                                       SHOST_DIF_TYPE2_PROTECTION,
 857                                       SHOST_DIF_TYPE3_PROTECTION };
 858
 859        return shost->prot_capabilities & cap[target_type] ? target_type : 0;
 860}
 861
 862static inline unsigned int scsi_host_dix_capable(struct Scsi_Host *shost, unsigned int target_type)
 863{
 864#if defined(CONFIG_BLK_DEV_INTEGRITY)
 865        static unsigned char cap[] = { SHOST_DIX_TYPE0_PROTECTION,
 866                                       SHOST_DIX_TYPE1_PROTECTION,
 867                                       SHOST_DIX_TYPE2_PROTECTION,
 868                                       SHOST_DIX_TYPE3_PROTECTION };
 869
 870        return shost->prot_capabilities & cap[target_type];
 871#endif
 872        return 0;
 873}
 874
 875/*
 876 * All DIX-capable initiators must support the T10-mandated CRC
 877 * checksum.  Controllers can optionally implement the IP checksum
 878 * scheme which has much lower impact on system performance.  Note
 879 * that the main rationale for the checksum is to match integrity
 880 * metadata with data.  Detecting bit errors are a job for ECC memory
 881 * and buses.
 882 */
 883
 884enum scsi_host_guard_type {
 885        SHOST_DIX_GUARD_CRC = 1 << 0,
 886        SHOST_DIX_GUARD_IP  = 1 << 1,
 887};
 888
 889static inline void scsi_host_set_guard(struct Scsi_Host *shost, unsigned char type)
 890{
 891        shost->prot_guard_type = type;
 892}
 893
 894static inline unsigned char scsi_host_get_guard(struct Scsi_Host *shost)
 895{
 896        return shost->prot_guard_type;
 897}
 898
 899/* legacy interfaces */
 900extern struct Scsi_Host *scsi_register(struct scsi_host_template *, int);
 901extern void scsi_unregister(struct Scsi_Host *);
 902extern int scsi_host_set_state(struct Scsi_Host *, enum scsi_host_state);
 903
 904#endif /* _SCSI_SCSI_HOST_H */
 905