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Linus Torvalds1da177e2005-04-16 15:20:36 -07001#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>
Arjan van de Ven0b950672006-01-11 13:16:10 +01008#include <linux/mutex.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -07009
10struct block_device;
Christoph Hellwig7dfdc9a2005-10-31 18:49:52 +010011struct completion;
Linus Torvalds1da177e2005-04-16 15:20:36 -070012struct module;
13struct scsi_cmnd;
14struct scsi_device;
James Bottomleya283bd32005-05-24 12:06:38 -050015struct scsi_target;
Linus Torvalds1da177e2005-04-16 15:20:36 -070016struct Scsi_Host;
17struct scsi_host_cmd_pool;
18struct scsi_transport_template;
James Bottomley86e33a22006-08-30 09:45:51 -040019struct blk_queue_tags;
Linus Torvalds1da177e2005-04-16 15:20:36 -070020
21
22/*
23 * The various choices mean:
24 * NONE: Self evident. Host adapter is not capable of scatter-gather.
25 * ALL: Means that the host adapter module can do scatter-gather,
26 * and that there is no limit to the size of the table to which
27 * we scatter/gather data.
28 * Anything else: Indicates the maximum number of chains that can be
29 * used in one scatter-gather request.
30 */
31#define SG_NONE 0
32#define SG_ALL 0xff
33
34
35#define DISABLE_CLUSTERING 0
36#define ENABLE_CLUSTERING 1
37
38enum scsi_eh_timer_return {
39 EH_NOT_HANDLED,
40 EH_HANDLED,
41 EH_RESET_TIMER,
42};
43
44
45struct scsi_host_template {
46 struct module *module;
47 const char *name;
48
49 /*
50 * Used to initialize old-style drivers. For new-style drivers
51 * just perform all work in your module initialization function.
52 *
53 * Status: OBSOLETE
54 */
55 int (* detect)(struct scsi_host_template *);
56
57 /*
58 * Used as unload callback for hosts with old-style drivers.
59 *
60 * Status: OBSOLETE
61 */
62 int (* release)(struct Scsi_Host *);
63
64 /*
65 * The info function will return whatever useful information the
66 * developer sees fit. If not provided, then the name field will
67 * be used instead.
68 *
69 * Status: OPTIONAL
70 */
71 const char *(* info)(struct Scsi_Host *);
72
73 /*
74 * Ioctl interface
75 *
76 * Status: OPTIONAL
77 */
78 int (* ioctl)(struct scsi_device *dev, int cmd, void __user *arg);
79
80
81#ifdef CONFIG_COMPAT
82 /*
83 * Compat handler. Handle 32bit ABI.
84 * When unknown ioctl is passed return -ENOIOCTLCMD.
85 *
86 * Status: OPTIONAL
87 */
88 int (* compat_ioctl)(struct scsi_device *dev, int cmd, void __user *arg);
89#endif
90
91 /*
92 * The queuecommand function is used to queue up a scsi
93 * command block to the LLDD. When the driver finished
94 * processing the command the done callback is invoked.
95 *
96 * If queuecommand returns 0, then the HBA has accepted the
97 * command. The done() function must be called on the command
98 * when the driver has finished with it. (you may call done on the
99 * command before queuecommand returns, but in this case you
100 * *must* return 0 from queuecommand).
101 *
102 * Queuecommand may also reject the command, in which case it may
103 * not touch the command and must not call done() for it.
104 *
105 * There are two possible rejection returns:
106 *
107 * SCSI_MLQUEUE_DEVICE_BUSY: Block this device temporarily, but
108 * allow commands to other devices serviced by this host.
109 *
110 * SCSI_MLQUEUE_HOST_BUSY: Block all devices served by this
111 * host temporarily.
112 *
113 * For compatibility, any other non-zero return is treated the
114 * same as SCSI_MLQUEUE_HOST_BUSY.
115 *
116 * NOTE: "temporarily" means either until the next command for#
117 * this device/host completes, or a period of time determined by
118 * I/O pressure in the system if there are no other outstanding
119 * commands.
120 *
121 * STATUS: REQUIRED
122 */
123 int (* queuecommand)(struct scsi_cmnd *,
124 void (*done)(struct scsi_cmnd *));
125
126 /*
127 * This is an error handling strategy routine. You don't need to
128 * define one of these if you don't want to - there is a default
129 * routine that is present that should work in most cases. For those
130 * driver authors that have the inclination and ability to write their
131 * own strategy routine, this is where it is specified. Note - the
132 * strategy routine is *ALWAYS* run in the context of the kernel eh
133 * thread. Thus you are guaranteed to *NOT* be in an interrupt
134 * handler when you execute this, and you are also guaranteed to
135 * *NOT* have any other commands being queued while you are in the
136 * strategy routine. When you return from this function, operations
137 * return to normal.
138 *
139 * See scsi_error.c scsi_unjam_host for additional comments about
140 * what this function should and should not be attempting to do.
141 *
142 * Status: REQUIRED (at least one of them)
143 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700144 int (* eh_abort_handler)(struct scsi_cmnd *);
145 int (* eh_device_reset_handler)(struct scsi_cmnd *);
146 int (* eh_bus_reset_handler)(struct scsi_cmnd *);
147 int (* eh_host_reset_handler)(struct scsi_cmnd *);
148
149 /*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700150 * Before the mid layer attempts to scan for a new device where none
151 * currently exists, it will call this entry in your driver. Should
152 * your driver need to allocate any structs or perform any other init
153 * items in order to send commands to a currently unused target/lun
154 * combo, then this is where you can perform those allocations. This
155 * is specifically so that drivers won't have to perform any kind of
156 * "is this a new device" checks in their queuecommand routine,
157 * thereby making the hot path a bit quicker.
158 *
159 * Return values: 0 on success, non-0 on failure
160 *
161 * Deallocation: If we didn't find any devices at this ID, you will
162 * get an immediate call to slave_destroy(). If we find something
163 * here then you will get a call to slave_configure(), then the
164 * device will be used for however long it is kept around, then when
165 * the device is removed from the system (or * possibly at reboot
166 * time), you will then get a call to slave_destroy(). This is
167 * assuming you implement slave_configure and slave_destroy.
168 * However, if you allocate memory and hang it off the device struct,
169 * then you must implement the slave_destroy() routine at a minimum
170 * in order to avoid leaking memory
171 * each time a device is tore down.
172 *
173 * Status: OPTIONAL
174 */
175 int (* slave_alloc)(struct scsi_device *);
176
177 /*
178 * Once the device has responded to an INQUIRY and we know the
179 * device is online, we call into the low level driver with the
180 * struct scsi_device *. If the low level device driver implements
181 * this function, it *must* perform the task of setting the queue
182 * depth on the device. All other tasks are optional and depend
183 * on what the driver supports and various implementation details.
184 *
185 * Things currently recommended to be handled at this time include:
186 *
187 * 1. Setting the device queue depth. Proper setting of this is
188 * described in the comments for scsi_adjust_queue_depth.
189 * 2. Determining if the device supports the various synchronous
190 * negotiation protocols. The device struct will already have
191 * responded to INQUIRY and the results of the standard items
192 * will have been shoved into the various device flag bits, eg.
193 * device->sdtr will be true if the device supports SDTR messages.
194 * 3. Allocating command structs that the device will need.
195 * 4. Setting the default timeout on this device (if needed).
196 * 5. Anything else the low level driver might want to do on a device
197 * specific setup basis...
198 * 6. Return 0 on success, non-0 on error. The device will be marked
199 * as offline on error so that no access will occur. If you return
200 * non-0, your slave_destroy routine will never get called for this
201 * device, so don't leave any loose memory hanging around, clean
202 * up after yourself before returning non-0
203 *
204 * Status: OPTIONAL
205 */
206 int (* slave_configure)(struct scsi_device *);
207
208 /*
209 * Immediately prior to deallocating the device and after all activity
210 * has ceased the mid layer calls this point so that the low level
211 * driver may completely detach itself from the scsi device and vice
212 * versa. The low level driver is responsible for freeing any memory
213 * it allocated in the slave_alloc or slave_configure calls.
214 *
215 * Status: OPTIONAL
216 */
217 void (* slave_destroy)(struct scsi_device *);
218
219 /*
James Bottomleya283bd32005-05-24 12:06:38 -0500220 * Before the mid layer attempts to scan for a new device attached
221 * to a target where no target currently exists, it will call this
222 * entry in your driver. Should your driver need to allocate any
223 * structs or perform any other init items in order to send commands
224 * to a currently unused target, then this is where you can perform
225 * those allocations.
226 *
227 * Return values: 0 on success, non-0 on failure
228 *
229 * Status: OPTIONAL
230 */
231 int (* target_alloc)(struct scsi_target *);
232
233 /*
234 * Immediately prior to deallocating the target structure, and
235 * after all activity to attached scsi devices has ceased, the
236 * midlayer calls this point so that the driver may deallocate
237 * and terminate any references to the target.
238 *
239 * Status: OPTIONAL
240 */
241 void (* target_destroy)(struct scsi_target *);
242
243 /*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700244 * fill in this function to allow the queue depth of this host
245 * to be changeable (on a per device basis). returns either
246 * the current queue depth setting (may be different from what
247 * was passed in) or an error. An error should only be
248 * returned if the requested depth is legal but the driver was
249 * unable to set it. If the requested depth is illegal, the
250 * driver should set and return the closest legal queue depth.
251 *
252 */
253 int (* change_queue_depth)(struct scsi_device *, int);
254
255 /*
256 * fill in this function to allow the changing of tag types
257 * (this also allows the enabling/disabling of tag command
258 * queueing). An error should only be returned if something
259 * went wrong in the driver while trying to set the tag type.
260 * If the driver doesn't support the requested tag type, then
261 * it should set the closest type it does support without
262 * returning an error. Returns the actual tag type set.
263 */
264 int (* change_queue_type)(struct scsi_device *, int);
265
266 /*
267 * This function determines the bios parameters for a given
268 * harddisk. These tend to be numbers that are made up by
269 * the host adapter. Parameters:
270 * size, device, list (heads, sectors, cylinders)
271 *
272 * Status: OPTIONAL */
273 int (* bios_param)(struct scsi_device *, struct block_device *,
274 sector_t, int []);
275
276 /*
277 * Can be used to export driver statistics and other infos to the
278 * world outside the kernel ie. userspace and it also provides an
279 * interface to feed the driver with information.
280 *
281 * Status: OBSOLETE
282 */
283 int (*proc_info)(struct Scsi_Host *, char *, char **, off_t, int, int);
284
285 /*
Jens Axboe9b847542006-01-06 09:28:07 +0100286 * suspend support
287 */
288 int (*resume)(struct scsi_device *);
Nigel Cunningham082776e2006-03-23 23:22:16 +1000289 int (*suspend)(struct scsi_device *, pm_message_t state);
Jens Axboe9b847542006-01-06 09:28:07 +0100290
291 /*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700292 * Name of proc directory
293 */
294 char *proc_name;
295
296 /*
297 * Used to store the procfs directory if a driver implements the
298 * proc_info method.
299 */
300 struct proc_dir_entry *proc_dir;
301
302 /*
303 * This determines if we will use a non-interrupt driven
304 * or an interrupt driven scheme, It is set to the maximum number
305 * of simultaneous commands a given host adapter will accept.
306 */
307 int can_queue;
308
309 /*
310 * In many instances, especially where disconnect / reconnect are
311 * supported, our host also has an ID on the SCSI bus. If this is
312 * the case, then it must be reserved. Please set this_id to -1 if
313 * your setup is in single initiator mode, and the host lacks an
314 * ID.
315 */
316 int this_id;
317
318 /*
319 * This determines the degree to which the host adapter is capable
320 * of scatter-gather.
321 */
322 unsigned short sg_tablesize;
323
324 /*
325 * If the host adapter has limitations beside segment count
326 */
327 unsigned short max_sectors;
328
329 /*
330 * dma scatter gather segment boundary limit. a segment crossing this
331 * boundary will be split in two.
332 */
333 unsigned long dma_boundary;
334
335 /*
336 * This specifies "machine infinity" for host templates which don't
337 * limit the transfer size. Note this limit represents an absolute
338 * maximum, and may be over the transfer limits allowed for
339 * individual devices (e.g. 256 for SCSI-1)
340 */
341#define SCSI_DEFAULT_MAX_SECTORS 1024
342
343 /*
344 * True if this host adapter can make good use of linked commands.
345 * This will allow more than one command to be queued to a given
346 * unit on a given host. Set this to the maximum number of command
347 * blocks to be provided for each device. Set this to 1 for one
348 * command block per lun, 2 for two, etc. Do not set this to 0.
349 * You should make sure that the host adapter will do the right thing
350 * before you try setting this above 1.
351 */
352 short cmd_per_lun;
353
354 /*
355 * present contains counter indicating how many boards of this
356 * type were found when we did the scan.
357 */
358 unsigned char present;
359
360 /*
361 * true if this host adapter uses unchecked DMA onto an ISA bus.
362 */
363 unsigned unchecked_isa_dma:1;
364
365 /*
366 * true if this host adapter can make good use of clustering.
367 * I originally thought that if the tablesize was large that it
368 * was a waste of CPU cycles to prepare a cluster list, but
369 * it works out that the Buslogic is faster if you use a smaller
370 * number of segments (i.e. use clustering). I guess it is
371 * inefficient.
372 */
373 unsigned use_clustering:1;
374
375 /*
376 * True for emulated SCSI host adapters (e.g. ATAPI)
377 */
378 unsigned emulated:1;
379
380 /*
381 * True if the low-level driver performs its own reset-settle delays.
382 */
383 unsigned skip_settle_delay:1;
384
385 /*
386 * ordered write support
387 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700388 unsigned ordered_tag:1;
389
390 /*
391 * Countdown for host blocking with no commands outstanding
392 */
393 unsigned int max_host_blocked;
394
395 /*
396 * Default value for the blocking. If the queue is empty,
397 * host_blocked counts down in the request_fn until it restarts
398 * host operations as zero is reached.
399 *
400 * FIXME: This should probably be a value in the template
401 */
402#define SCSI_DEFAULT_HOST_BLOCKED 7
403
404 /*
405 * Pointer to the sysfs class properties for this host, NULL terminated.
406 */
407 struct class_device_attribute **shost_attrs;
408
409 /*
410 * Pointer to the SCSI device properties for this host, NULL terminated.
411 */
412 struct device_attribute **sdev_attrs;
413
414 /*
415 * List of hosts per template.
416 *
417 * This is only for use by scsi_module.c for legacy templates.
418 * For these access to it is synchronized implicitly by
419 * module_init/module_exit.
420 */
421 struct list_head legacy_hosts;
422};
423
424/*
Mike Andersond3301872005-06-16 11:12:38 -0700425 * shost state: If you alter this, you also need to alter scsi_sysfs.c
426 * (for the ascii descriptions) and the state model enforcer:
427 * scsi_host_set_state()
Linus Torvalds1da177e2005-04-16 15:20:36 -0700428 */
Mike Andersond3301872005-06-16 11:12:38 -0700429enum scsi_host_state {
430 SHOST_CREATED = 1,
431 SHOST_RUNNING,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700432 SHOST_CANCEL,
Mike Andersond3301872005-06-16 11:12:38 -0700433 SHOST_DEL,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700434 SHOST_RECOVERY,
James Bottomley939647e2005-09-18 15:05:20 -0500435 SHOST_CANCEL_RECOVERY,
436 SHOST_DEL_RECOVERY,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700437};
438
439struct Scsi_Host {
440 /*
441 * __devices is protected by the host_lock, but you should
442 * usually use scsi_device_lookup / shost_for_each_device
443 * to access it and don't care about locking yourself.
444 * In the rare case of beeing in irq context you can use
445 * their __ prefixed variants with the lock held. NEVER
446 * access this list directly from a driver.
447 */
448 struct list_head __devices;
449 struct list_head __targets;
450
451 struct scsi_host_cmd_pool *cmd_pool;
452 spinlock_t free_list_lock;
453 struct list_head free_list; /* backup store of cmd structs */
454 struct list_head starved_list;
455
456 spinlock_t default_lock;
457 spinlock_t *host_lock;
458
Arjan van de Ven0b950672006-01-11 13:16:10 +0100459 struct mutex scan_mutex;/* serialize scanning activity */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700460
461 struct list_head eh_cmd_q;
462 struct task_struct * ehandler; /* Error recovery thread. */
Christoph Hellwig7dfdc9a2005-10-31 18:49:52 +0100463 struct completion * eh_action; /* Wait for specific actions on the
464 host. */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700465 wait_queue_head_t host_wait;
466 struct scsi_host_template *hostt;
467 struct scsi_transport_template *transportt;
06f81ea2005-04-17 14:57:29 -0500468
469 /*
James Bottomley86e33a22006-08-30 09:45:51 -0400470 * area to keep a shared tag map (if needed, will be
471 * NULL if not)
472 */
473 struct blk_queue_tag *bqt;
474
475 /*
06f81ea2005-04-17 14:57:29 -0500476 * The following two fields are protected with host_lock;
477 * however, eh routines can safely access during eh processing
478 * without acquiring the lock.
479 */
480 unsigned int host_busy; /* commands actually active on low-level */
481 unsigned int host_failed; /* commands that failed. */
Tejun Heoee7863b2006-05-15 20:57:20 +0900482 unsigned int host_eh_scheduled; /* EH scheduled without command */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700483
484 unsigned short host_no; /* Used for IOCTL_GET_IDLUN, /proc/scsi et al. */
485 int resetting; /* if set, it means that last_reset is a valid value */
486 unsigned long last_reset;
487
488 /*
489 * These three parameters can be used to allow for wide scsi,
490 * and for host adapters that support multiple busses
491 * The first two should be set to 1 more than the actual max id
492 * or lun (i.e. 8 for normal systems).
493 */
494 unsigned int max_id;
495 unsigned int max_lun;
496 unsigned int max_channel;
497
498 /*
499 * This is a unique identifier that must be assigned so that we
500 * have some way of identifying each detected host adapter properly
501 * and uniquely. For hosts that do not support more than one card
502 * in the system at one time, this does not need to be set. It is
503 * initialized to 0 in scsi_register.
504 */
505 unsigned int unique_id;
506
507 /*
508 * The maximum length of SCSI commands that this host can accept.
509 * Probably 12 for most host adapters, but could be 16 for others.
510 * For drivers that don't set this field, a value of 12 is
511 * assumed. I am leaving this as a number rather than a bit
512 * because you never know what subsequent SCSI standards might do
513 * (i.e. could there be a 20 byte or a 24-byte command a few years
514 * down the road?).
515 */
516 unsigned char max_cmd_len;
517
518 int this_id;
519 int can_queue;
520 short cmd_per_lun;
521 short unsigned int sg_tablesize;
522 short unsigned int max_sectors;
523 unsigned long dma_boundary;
524 /*
525 * Used to assign serial numbers to the cmds.
526 * Protected by the host lock.
527 */
528 unsigned long cmd_serial_number, cmd_pid;
529
530 unsigned unchecked_isa_dma:1;
531 unsigned use_clustering:1;
532 unsigned use_blk_tcq:1;
533
534 /*
535 * Host has requested that no further requests come through for the
536 * time being.
537 */
538 unsigned host_self_blocked:1;
539
540 /*
541 * Host uses correct SCSI ordering not PC ordering. The bit is
542 * set for the minority of drivers whose authors actually read
543 * the spec ;)
544 */
545 unsigned reverse_ordering:1;
546
547 /*
548 * ordered write support
549 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700550 unsigned ordered_tag:1;
551
James Smartd7a1bb02006-03-08 14:50:12 -0500552 /* task mgmt function in progress */
553 unsigned tmf_in_progress:1;
554
Linus Torvalds1da177e2005-04-16 15:20:36 -0700555 /*
556 * Optional work queue to be utilized by the transport
557 */
558 char work_q_name[KOBJ_NAME_LEN];
559 struct workqueue_struct *work_q;
560
561 /*
562 * Host has rejected a command because it was busy.
563 */
564 unsigned int host_blocked;
565
566 /*
567 * Value host_blocked counts down from
568 */
569 unsigned int max_host_blocked;
570
571 /* legacy crap */
572 unsigned long base;
573 unsigned long io_port;
574 unsigned char n_io_port;
575 unsigned char dma_channel;
576 unsigned int irq;
577
578
Mike Andersond3301872005-06-16 11:12:38 -0700579 enum scsi_host_state shost_state;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700580
581 /* ldm bits */
582 struct device shost_gendev;
583 struct class_device shost_classdev;
584
585 /*
586 * List of hosts per template.
587 *
588 * This is only for use by scsi_module.c for legacy templates.
589 * For these access to it is synchronized implicitly by
590 * module_init/module_exit.
591 */
592 struct list_head sht_legacy_list;
593
594 /*
595 * Points to the transport data (if any) which is allocated
596 * separately
597 */
598 void *shost_data;
599
600 /*
601 * We should ensure that this is aligned, both for better performance
602 * and also because some compilers (m68k) don't automatically force
603 * alignment to a long boundary.
604 */
605 unsigned long hostdata[0] /* Used for storage of host specific stuff */
606 __attribute__ ((aligned (sizeof(unsigned long))));
607};
608
609#define class_to_shost(d) \
610 container_of(d, struct Scsi_Host, shost_classdev)
611
James Bottomley9ccfc752005-10-02 11:45:08 -0500612#define shost_printk(prefix, shost, fmt, a...) \
613 dev_printk(prefix, &(shost)->shost_gendev, fmt, ##a)
614
615
Linus Torvalds1da177e2005-04-16 15:20:36 -0700616int scsi_is_host_device(const struct device *);
617
618static inline struct Scsi_Host *dev_to_shost(struct device *dev)
619{
620 while (!scsi_is_host_device(dev)) {
621 if (!dev->parent)
622 return NULL;
623 dev = dev->parent;
624 }
625 return container_of(dev, struct Scsi_Host, shost_gendev);
626}
627
James Bottomley939647e2005-09-18 15:05:20 -0500628static inline int scsi_host_in_recovery(struct Scsi_Host *shost)
629{
630 return shost->shost_state == SHOST_RECOVERY ||
631 shost->shost_state == SHOST_CANCEL_RECOVERY ||
James Smartd7a1bb02006-03-08 14:50:12 -0500632 shost->shost_state == SHOST_DEL_RECOVERY ||
633 shost->tmf_in_progress;
James Bottomley939647e2005-09-18 15:05:20 -0500634}
635
Linus Torvalds1da177e2005-04-16 15:20:36 -0700636extern int scsi_queue_work(struct Scsi_Host *, struct work_struct *);
637extern void scsi_flush_work(struct Scsi_Host *);
638
639extern struct Scsi_Host *scsi_host_alloc(struct scsi_host_template *, int);
640extern int __must_check scsi_add_host(struct Scsi_Host *, struct device *);
641extern void scsi_scan_host(struct Scsi_Host *);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700642extern void scsi_rescan_device(struct device *);
643extern void scsi_remove_host(struct Scsi_Host *);
644extern struct Scsi_Host *scsi_host_get(struct Scsi_Host *);
645extern void scsi_host_put(struct Scsi_Host *t);
646extern struct Scsi_Host *scsi_host_lookup(unsigned short);
Mike Andersond3301872005-06-16 11:12:38 -0700647extern const char *scsi_host_state_name(enum scsi_host_state);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700648
649extern u64 scsi_calculate_bounce_limit(struct Scsi_Host *);
650
651static inline void scsi_assign_lock(struct Scsi_Host *shost, spinlock_t *lock)
652{
653 shost->host_lock = lock;
654}
655
Linus Torvalds1da177e2005-04-16 15:20:36 -0700656static inline struct device *scsi_get_device(struct Scsi_Host *shost)
657{
658 return shost->shost_gendev.parent;
659}
660
Mike Anderson82f29462005-06-16 11:14:33 -0700661/**
662 * scsi_host_scan_allowed - Is scanning of this host allowed
663 * @shost: Pointer to Scsi_Host.
664 **/
665static inline int scsi_host_scan_allowed(struct Scsi_Host *shost)
666{
667 return shost->shost_state == SHOST_RUNNING;
668}
669
Linus Torvalds1da177e2005-04-16 15:20:36 -0700670extern void scsi_unblock_requests(struct Scsi_Host *);
671extern void scsi_block_requests(struct Scsi_Host *);
672
673struct class_container;
674/*
675 * These two functions are used to allocate and free a pseudo device
676 * which will connect to the host adapter itself rather than any
677 * physical device. You must deallocate when you are done with the
678 * thing. This physical pseudo-device isn't real and won't be available
679 * from any high-level drivers.
680 */
681extern void scsi_free_host_dev(struct scsi_device *);
682extern struct scsi_device *scsi_get_host_dev(struct Scsi_Host *);
683
684/* legacy interfaces */
685extern struct Scsi_Host *scsi_register(struct scsi_host_template *, int);
686extern void scsi_unregister(struct Scsi_Host *);
James Bottomley47ba39e2005-07-30 11:39:53 -0500687extern int scsi_host_set_state(struct Scsi_Host *, enum scsi_host_state);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700688
689#endif /* _SCSI_SCSI_HOST_H */