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54 * Status: OBSOLETE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61 * Status: OBSOLETE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