Root/include/scsi/scsi_host.h

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60     * Status: OBSOLETE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67     * Status: OBSOLETE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

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