1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _SCSI_SCSI_HOST_H
3 #define _SCSI_SCSI_HOST_H
4
5 #include <linux/device.h>
6 #include <linux/list.h>
7 #include <linux/types.h>
8 #include <linux/workqueue.h>
9 #include <linux/mutex.h>
10 #include <linux/seq_file.h>
11 #include <linux/blk-mq.h>
12 #include <scsi/scsi.h>
13
14 struct block_device;
15 struct completion;
16 struct module;
17 struct scsi_cmnd;
18 struct scsi_device;
19 struct scsi_host_cmd_pool;
20 struct scsi_target;
21 struct Scsi_Host;
22 struct scsi_host_cmd_pool;
23 struct scsi_transport_template;
24
25
26 /*
27 * The various choices mean:
28 * NONE: Self evident. Host adapter is not capable of scatter-gather.
29 * ALL: Means that the host adapter module can do scatter-gather,
30 * and that there is no limit to the size of the table to which
31 * we scatter/gather data. The value we set here is the maximum
32 * single element sglist. To use chained sglists, the adapter
33 * has to set a value beyond ALL (and correctly use the chain
34 * handling API.
35 * Anything else: Indicates the maximum number of chains that can be
36 * used in one scatter-gather request.
37 */
38 #define SG_NONE 0
39 #define SG_ALL SG_CHUNK_SIZE
40
41 #define MODE_UNKNOWN 0x00
42 #define MODE_INITIATOR 0x01
43 #define MODE_TARGET 0x02
44
45 struct scsi_host_template {
46 struct module *module;
47 const char *name;
48
49 /*
50 * The info function will return whatever useful information the
51 * developer sees fit. If not provided, then the name field will
52 * be used instead.
53 *
54 * Status: OPTIONAL
55 */
56 const char *(* info)(struct Scsi_Host *);
57
58 /*
59 * Ioctl interface
60 *
61 * Status: OPTIONAL
62 */
63 int (*ioctl)(struct scsi_device *dev, unsigned int cmd,
64 void __user *arg);
65
66
67 #ifdef CONFIG_COMPAT
68 /*
69 * Compat handler. Handle 32bit ABI.
70 * When unknown ioctl is passed return -ENOIOCTLCMD.
71 *
72 * Status: OPTIONAL
73 */
74 int (*compat_ioctl)(struct scsi_device *dev, unsigned int cmd,
75 void __user *arg);
76 #endif
77
78 /*
79 * The queuecommand function is used to queue up a scsi
80 * command block to the LLDD. When the driver finished
81 * processing the command the done callback is invoked.
82 *
83 * If queuecommand returns 0, then the driver has accepted the
84 * command. It must also push it to the HBA if the scsi_cmnd
85 * flag SCMD_LAST is set, or if the driver does not implement
86 * commit_rqs. The done() function must be called on the command
87 * when the driver has finished with it. (you may call done on the
88 * command before queuecommand returns, but in this case you
89 * *must* return 0 from queuecommand).
90 *
91 * Queuecommand may also reject the command, in which case it may
92 * not touch the command and must not call done() for it.
93 *
94 * There are two possible rejection returns:
95 *
96 * SCSI_MLQUEUE_DEVICE_BUSY: Block this device temporarily, but
97 * allow commands to other devices serviced by this host.
98 *
99 * SCSI_MLQUEUE_HOST_BUSY: Block all devices served by this
100 * host temporarily.
101 *
102 * For compatibility, any other non-zero return is treated the
103 * same as SCSI_MLQUEUE_HOST_BUSY.
104 *
105 * NOTE: "temporarily" means either until the next command for#
106 * this device/host completes, or a period of time determined by
107 * I/O pressure in the system if there are no other outstanding
108 * commands.
109 *
110 * STATUS: REQUIRED
111 */
112 int (* queuecommand)(struct Scsi_Host *, struct scsi_cmnd *);
113
114 /*
115 * The commit_rqs function is used to trigger a hardware
116 * doorbell after some requests have been queued with
117 * queuecommand, when an error is encountered before sending
118 * the request with SCMD_LAST set.
119 *
120 * STATUS: OPTIONAL
121 */
122 void (*commit_rqs)(struct Scsi_Host *, u16);
123
124 /*
125 * This is an error handling strategy routine. You don't need to
126 * define one of these if you don't want to - there is a default
127 * routine that is present that should work in most cases. For those
128 * driver authors that have the inclination and ability to write their
129 * own strategy routine, this is where it is specified. Note - the
130 * strategy routine is *ALWAYS* run in the context of the kernel eh
131 * thread. Thus you are guaranteed to *NOT* be in an interrupt
132 * handler when you execute this, and you are also guaranteed to
133 * *NOT* have any other commands being queued while you are in the
134 * strategy routine. When you return from this function, operations
135 * return to normal.
136 *
137 * See scsi_error.c scsi_unjam_host for additional comments about
138 * what this function should and should not be attempting to do.
139 *
140 * Status: REQUIRED (at least one of them)
141 */
142 int (* eh_abort_handler)(struct scsi_cmnd *);
143 int (* eh_device_reset_handler)(struct scsi_cmnd *);
144 int (* eh_target_reset_handler)(struct scsi_cmnd *);
145 int (* eh_bus_reset_handler)(struct scsi_cmnd *);
146 int (* eh_host_reset_handler)(struct scsi_cmnd *);
147
148 /*
149 * Before the mid layer attempts to scan for a new device where none
150 * currently exists, it will call this entry in your driver. Should
151 * your driver need to allocate any structs or perform any other init
152 * items in order to send commands to a currently unused target/lun
153 * combo, then this is where you can perform those allocations. This
154 * is specifically so that drivers won't have to perform any kind of
155 * "is this a new device" checks in their queuecommand routine,
156 * thereby making the hot path a bit quicker.
157 *
158 * Return values: 0 on success, non-0 on failure
159 *
160 * Deallocation: If we didn't find any devices at this ID, you will
161 * get an immediate call to slave_destroy(). If we find something
162 * here then you will get a call to slave_configure(), then the
163 * device will be used for however long it is kept around, then when
164 * the device is removed from the system (or * possibly at reboot
165 * time), you will then get a call to slave_destroy(). This is
166 * assuming you implement slave_configure and slave_destroy.
167 * However, if you allocate memory and hang it off the device struct,
168 * then you must implement the slave_destroy() routine at a minimum
169 * in order to avoid leaking memory
170 * each time a device is tore down.
171 *
172 * Status: OPTIONAL
173 */
174 int (* slave_alloc)(struct scsi_device *);
175
176 /*
177 * Once the device has responded to an INQUIRY and we know the
178 * device is online, we call into the low level driver with the
179 * struct scsi_device *. If the low level device driver implements
180 * this function, it *must* perform the task of setting the queue
181 * depth on the device. All other tasks are optional and depend
182 * on what the driver supports and various implementation details.
183 *
184 * Things currently recommended to be handled at this time include:
185 *
186 * 1. Setting the device queue depth. Proper setting of this is
187 * described in the comments for scsi_change_queue_depth.
188 * 2. Determining if the device supports the various synchronous
189 * negotiation protocols. The device struct will already have
190 * responded to INQUIRY and the results of the standard items
191 * will have been shoved into the various device flag bits, eg.
192 * device->sdtr will be true if the device supports SDTR messages.
193 * 3. Allocating command structs that the device will need.
194 * 4. Setting the default timeout on this device (if needed).
195 * 5. Anything else the low level driver might want to do on a device
196 * specific setup basis...
197 * 6. Return 0 on success, non-0 on error. The device will be marked
198 * as offline on error so that no access will occur. If you return
199 * non-0, your slave_destroy routine will never get called for this
200 * device, so don't leave any loose memory hanging around, clean
201 * up after yourself before returning non-0
202 *
203 * Status: OPTIONAL
204 */
205 int (* slave_configure)(struct scsi_device *);
206
207 /*
208 * Immediately prior to deallocating the device and after all activity
209 * has ceased the mid layer calls this point so that the low level
210 * driver may completely detach itself from the scsi device and vice
211 * versa. The low level driver is responsible for freeing any memory
212 * it allocated in the slave_alloc or slave_configure calls.
213 *
214 * Status: OPTIONAL
215 */
216 void (* slave_destroy)(struct scsi_device *);
217
218 /*
219 * Before the mid layer attempts to scan for a new device attached
220 * to a target where no target currently exists, it will call this
221 * entry in your driver. Should your driver need to allocate any
222 * structs or perform any other init items in order to send commands
223 * to a currently unused target, then this is where you can perform
224 * those allocations.
225 *
226 * Return values: 0 on success, non-0 on failure
227 *
228 * Status: OPTIONAL
229 */
230 int (* target_alloc)(struct scsi_target *);
231
232 /*
233 * Immediately prior to deallocating the target structure, and
234 * after all activity to attached scsi devices has ceased, the
235 * midlayer calls this point so that the driver may deallocate
236 * and terminate any references to the target.
237 *
238 * Status: OPTIONAL
239 */
240 void (* target_destroy)(struct scsi_target *);
241
242 /*
243 * If a host has the ability to discover targets on its own instead
244 * of scanning the entire bus, it can fill in this function and
245 * call scsi_scan_host(). This function will be called periodically
246 * until it returns 1 with the scsi_host and the elapsed time of
247 * the scan in jiffies.
248 *
249 * Status: OPTIONAL
250 */
251 int (* scan_finished)(struct Scsi_Host *, unsigned long);
252
253 /*
254 * If the host wants to be called before the scan starts, but
255 * after the midlayer has set up ready for the scan, it can fill
256 * in this function.
257 *
258 * Status: OPTIONAL
259 */
260 void (* scan_start)(struct Scsi_Host *);
261
262 /*
263 * Fill in this function to allow the queue depth of this host
264 * to be changeable (on a per device basis). Returns either
265 * the current queue depth setting (may be different from what
266 * was passed in) or an error. An error should only be
267 * returned if the requested depth is legal but the driver was
268 * unable to set it. If the requested depth is illegal, the
269 * driver should set and return the closest legal queue depth.
270 *
271 * Status: OPTIONAL
272 */
273 int (* change_queue_depth)(struct scsi_device *, int);
274
275 /*
276 * This functions lets the driver expose the queue mapping
277 * to the block layer.
278 *
279 * Status: OPTIONAL
280 */
281 int (* map_queues)(struct Scsi_Host *shost);
282
283 /*
284 * This function determines the BIOS parameters for a given
285 * harddisk. These tend to be numbers that are made up by
286 * the host adapter. Parameters:
287 * size, device, list (heads, sectors, cylinders)
288 *
289 * Status: OPTIONAL
290 */
291 int (* bios_param)(struct scsi_device *, struct block_device *,
292 sector_t, int []);
293
294 /*
295 * This function is called when one or more partitions on the
296 * device reach beyond the end of the device.
297 *
298 * Status: OPTIONAL
299 */
300 void (*unlock_native_capacity)(struct scsi_device *);
301
302 /*
303 * Can be used to export driver statistics and other infos to the
304 * world outside the kernel ie. userspace and it also provides an
305 * interface to feed the driver with information.
306 *
307 * Status: OBSOLETE
308 */
309 int (*show_info)(struct seq_file *, struct Scsi_Host *);
310 int (*write_info)(struct Scsi_Host *, char *, int);
311
312 /*
313 * This is an optional routine that allows the transport to become
314 * involved when a scsi io timer fires. The return value tells the
315 * timer routine how to finish the io timeout handling.
316 *
317 * Status: OPTIONAL
318 */
319 enum blk_eh_timer_return (*eh_timed_out)(struct scsi_cmnd *);
320
321 /* This is an optional routine that allows transport to initiate
322 * LLD adapter or firmware reset using sysfs attribute.
323 *
324 * Return values: 0 on success, -ve value on failure.
325 *
326 * Status: OPTIONAL
327 */
328
329 int (*host_reset)(struct Scsi_Host *shost, int reset_type);
330 #define SCSI_ADAPTER_RESET 1
331 #define SCSI_FIRMWARE_RESET 2
332
333
334 /*
335 * Name of proc directory
336 */
337 const char *proc_name;
338
339 /*
340 * Used to store the procfs directory if a driver implements the
341 * show_info method.
342 */
343 struct proc_dir_entry *proc_dir;
344
345 /*
346 * This determines if we will use a non-interrupt driven
347 * or an interrupt driven scheme. It is set to the maximum number
348 * of simultaneous commands a given host adapter will accept.
349 */
350 int can_queue;
351
352 /*
353 * In many instances, especially where disconnect / reconnect are
354 * supported, our host also has an ID on the SCSI bus. If this is
355 * the case, then it must be reserved. Please set this_id to -1 if
356 * your setup is in single initiator mode, and the host lacks an
357 * ID.
358 */
359 int this_id;
360
361 /*
362 * This determines the degree to which the host adapter is capable
363 * of scatter-gather.
364 */
365 unsigned short sg_tablesize;
366 unsigned short sg_prot_tablesize;
367
368 /*
369 * Set this if the host adapter has limitations beside segment count.
370 */
371 unsigned int max_sectors;
372
373 /*
374 * Maximum size in bytes of a single segment.
375 */
376 unsigned int max_segment_size;
377
378 /*
379 * DMA scatter gather segment boundary limit. A segment crossing this
380 * boundary will be split in two.
381 */
382 unsigned long dma_boundary;
383
384 unsigned long virt_boundary_mask;
385
386 /*
387 * This specifies "machine infinity" for host templates which don't
388 * limit the transfer size. Note this limit represents an absolute
389 * maximum, and may be over the transfer limits allowed for
390 * individual devices (e.g. 256 for SCSI-1).
391 */
392 #define SCSI_DEFAULT_MAX_SECTORS 1024
393
394 /*
395 * True if this host adapter can make good use of linked commands.
396 * This will allow more than one command to be queued to a given
397 * unit on a given host. Set this to the maximum number of command
398 * blocks to be provided for each device. Set this to 1 for one
399 * command block per lun, 2 for two, etc. Do not set this to 0.
400 * You should make sure that the host adapter will do the right thing
401 * before you try setting this above 1.
402 */
403 short cmd_per_lun;
404
405 /*
406 * present contains counter indicating how many boards of this
407 * type were found when we did the scan.
408 */
409 unsigned char present;
410
411 /* If use block layer to manage tags, this is tag allocation policy */
412 int tag_alloc_policy;
413
414 /*
415 * Track QUEUE_FULL events and reduce queue depth on demand.
416 */
417 unsigned track_queue_depth:1;
418
419 /*
420 * This specifies the mode that a LLD supports.
421 */
422 unsigned supported_mode:2;
423
424 /*
425 * True if this host adapter uses unchecked DMA onto an ISA bus.
426 */
427 unsigned unchecked_isa_dma:1;
428
429 /*
430 * True for emulated SCSI host adapters (e.g. ATAPI).
431 */
432 unsigned emulated:1;
433
434 /*
435 * True if the low-level driver performs its own reset-settle delays.
436 */
437 unsigned skip_settle_delay:1;
438
439 /* True if the controller does not support WRITE SAME */
440 unsigned no_write_same:1;
441
442 /* True if the low-level driver supports blk-mq only */
443 unsigned force_blk_mq:1;
444
445 /*
446 * Countdown for host blocking with no commands outstanding.
447 */
448 unsigned int max_host_blocked;
449
450 /*
451 * Default value for the blocking. If the queue is empty,
452 * host_blocked counts down in the request_fn until it restarts
453 * host operations as zero is reached.
454 *
455 * FIXME: This should probably be a value in the template
456 */
457 #define SCSI_DEFAULT_HOST_BLOCKED 7
458
459 /*
460 * Pointer to the sysfs class properties for this host, NULL terminated.
461 */
462 struct device_attribute **shost_attrs;
463
464 /*
465 * Pointer to the SCSI device properties for this host, NULL terminated.
466 */
467 struct device_attribute **sdev_attrs;
468
469 /*
470 * Pointer to the SCSI device attribute groups for this host,
471 * NULL terminated.
472 */
473 const struct attribute_group **sdev_groups;
474
475 /*
476 * Vendor Identifier associated with the host
477 *
478 * Note: When specifying vendor_id, be sure to read the
479 * Vendor Type and ID formatting requirements specified in
480 * scsi_netlink.h
481 */
482 u64 vendor_id;
483
484 /*
485 * Additional per-command data allocated for the driver.
486 */
487 unsigned int cmd_size;
488 struct scsi_host_cmd_pool *cmd_pool;
489 };
490
491 /*
492 * Temporary #define for host lock push down. Can be removed when all
493 * drivers have been updated to take advantage of unlocked
494 * queuecommand.
495 *
496 */
497 #define DEF_SCSI_QCMD(func_name) \
498 int func_name(struct Scsi_Host *shost, struct scsi_cmnd *cmd) \
499 { \
500 unsigned long irq_flags; \
501 int rc; \
502 spin_lock_irqsave(shost->host_lock, irq_flags); \
503 rc = func_name##_lck (cmd, cmd->scsi_done); \
504 spin_unlock_irqrestore(shost->host_lock, irq_flags); \
505 return rc; \
506 }
507
508
509 /*
510 * shost state: If you alter this, you also need to alter scsi_sysfs.c
511 * (for the ascii descriptions) and the state model enforcer:
512 * scsi_host_set_state()
513 */
514 enum scsi_host_state {
515 SHOST_CREATED = 1,
516 SHOST_RUNNING,
517 SHOST_CANCEL,
518 SHOST_DEL,
519 SHOST_RECOVERY,
520 SHOST_CANCEL_RECOVERY,
521 SHOST_DEL_RECOVERY,
522 };
523
524 struct Scsi_Host {
525 /*
526 * __devices is protected by the host_lock, but you should
527 * usually use scsi_device_lookup / shost_for_each_device
528 * to access it and don't care about locking yourself.
529 * In the rare case of being in irq context you can use
530 * their __ prefixed variants with the lock held. NEVER
531 * access this list directly from a driver.
532 */
533 struct list_head __devices;
534 struct list_head __targets;
535
536 struct list_head starved_list;
537
538 spinlock_t default_lock;
539 spinlock_t *host_lock;
540
541 struct mutex scan_mutex;/* serialize scanning activity */
542
543 struct list_head eh_cmd_q;
544 struct task_struct * ehandler; /* Error recovery thread. */
545 struct completion * eh_action; /* Wait for specific actions on the
546 host. */
547 wait_queue_head_t host_wait;
548 struct scsi_host_template *hostt;
549 struct scsi_transport_template *transportt;
550
551 /* Area to keep a shared tag map */
552 struct blk_mq_tag_set tag_set;
553
554 atomic_t host_busy; /* commands actually active on low-level */
555 atomic_t host_blocked;
556
557 unsigned int host_failed; /* commands that failed.
558 protected by host_lock */
559 unsigned int host_eh_scheduled; /* EH scheduled without command */
560
561 unsigned int host_no; /* Used for IOCTL_GET_IDLUN, /proc/scsi et al. */
562
563 /* next two fields are used to bound the time spent in error handling */
564 int eh_deadline;
565 unsigned long last_reset;
566
567
568 /*
569 * These three parameters can be used to allow for wide scsi,
570 * and for host adapters that support multiple busses
571 * The last two should be set to 1 more than the actual max id
572 * or lun (e.g. 8 for SCSI parallel systems).
573 */
574 unsigned int max_channel;
575 unsigned int max_id;
576 u64 max_lun;
577
578 /*
579 * This is a unique identifier that must be assigned so that we
580 * have some way of identifying each detected host adapter properly
581 * and uniquely. For hosts that do not support more than one card
582 * in the system at one time, this does not need to be set. It is
583 * initialized to 0 in scsi_register.
584 */
585 unsigned int unique_id;
586
587 /*
588 * The maximum length of SCSI commands that this host can accept.
589 * Probably 12 for most host adapters, but could be 16 for others.
590 * or 260 if the driver supports variable length cdbs.
591 * For drivers that don't set this field, a value of 12 is
592 * assumed.
593 */
594 unsigned short max_cmd_len;
595
596 int this_id;
597 int can_queue;
598 short cmd_per_lun;
599 short unsigned int sg_tablesize;
600 short unsigned int sg_prot_tablesize;
601 unsigned int max_sectors;
602 unsigned int max_segment_size;
603 unsigned long dma_boundary;
604 unsigned long virt_boundary_mask;
605 /*
606 * In scsi-mq mode, the number of hardware queues supported by the LLD.
607 *
608 * Note: it is assumed that each hardware queue has a queue depth of
609 * can_queue. In other words, the total queue depth per host
610 * is nr_hw_queues * can_queue.
611 */
612 unsigned nr_hw_queues;
613 unsigned active_mode:2;
614 unsigned unchecked_isa_dma:1;
615
616 /*
617 * Host has requested that no further requests come through for the
618 * time being.
619 */
620 unsigned host_self_blocked:1;
621
622 /*
623 * Host uses correct SCSI ordering not PC ordering. The bit is
624 * set for the minority of drivers whose authors actually read
625 * the spec ;).
626 */
627 unsigned reverse_ordering:1;
628
629 /* Task mgmt function in progress */
630 unsigned tmf_in_progress:1;
631
632 /* Asynchronous scan in progress */
633 unsigned async_scan:1;
634
635 /* Don't resume host in EH */
636 unsigned eh_noresume:1;
637
638 /* The controller does not support WRITE SAME */
639 unsigned no_write_same:1;
640
641 unsigned use_cmd_list:1;
642
643 /* Host responded with short (<36 bytes) INQUIRY result */
644 unsigned short_inquiry:1;
645
646 /* The transport requires the LUN bits NOT to be stored in CDB[1] */
647 unsigned no_scsi2_lun_in_cdb:1;
648
649 /*
650 * Optional work queue to be utilized by the transport
651 */
652 char work_q_name[20];
653 struct workqueue_struct *work_q;
654
655 /*
656 * Task management function work queue
657 */
658 struct workqueue_struct *tmf_work_q;
659
660 /*
661 * Value host_blocked counts down from
662 */
663 unsigned int max_host_blocked;
664
665 /* Protection Information */
666 unsigned int prot_capabilities;
667 unsigned char prot_guard_type;
668
669 /* legacy crap */
670 unsigned long base;
671 unsigned long io_port;
672 unsigned char n_io_port;
673 unsigned char dma_channel;
674 unsigned int irq;
675
676
677 enum scsi_host_state shost_state;
678
679 /* ldm bits */
680 struct device shost_gendev, shost_dev;
681
682 /*
683 * Points to the transport data (if any) which is allocated
684 * separately
685 */
686 void *shost_data;
687
688 /*
689 * Points to the physical bus device we'd use to do DMA
690 * Needed just in case we have virtual hosts.
691 */
692 struct device *dma_dev;
693
694 /*
695 * We should ensure that this is aligned, both for better performance
696 * and also because some compilers (m68k) don't automatically force
697 * alignment to a long boundary.
698 */
699 unsigned long hostdata[0] /* Used for storage of host specific stuff */
700 __attribute__ ((aligned (sizeof(unsigned long))));
701 };
702
703 #define class_to_shost(d) \
704 container_of(d, struct Scsi_Host, shost_dev)
705
706 #define shost_printk(prefix, shost, fmt, a...) \
707 dev_printk(prefix, &(shost)->shost_gendev, fmt, ##a)
708
709 static inline void *shost_priv(struct Scsi_Host *shost)
710 {
711 return (void *)shost->hostdata;
712 }
713
714 int scsi_is_host_device(const struct device *);
715
716 static inline struct Scsi_Host *dev_to_shost(struct device *dev)
717 {
718 while (!scsi_is_host_device(dev)) {
719 if (!dev->parent)
720 return NULL;
721 dev = dev->parent;
722 }
723 return container_of(dev, struct Scsi_Host, shost_gendev);
724 }
725
726 static inline int scsi_host_in_recovery(struct Scsi_Host *shost)
727 {
728 return shost->shost_state == SHOST_RECOVERY ||
729 shost->shost_state == SHOST_CANCEL_RECOVERY ||
730 shost->shost_state == SHOST_DEL_RECOVERY ||
731 shost->tmf_in_progress;
732 }
733
734 extern int scsi_queue_work(struct Scsi_Host *, struct work_struct *);
735 extern void scsi_flush_work(struct Scsi_Host *);
736
737 extern struct Scsi_Host *scsi_host_alloc(struct scsi_host_template *, int);
738 extern int __must_check scsi_add_host_with_dma(struct Scsi_Host *,
739 struct device *,
740 struct device *);
741 extern void scsi_scan_host(struct Scsi_Host *);
742 extern void scsi_rescan_device(struct device *);
743 extern void scsi_remove_host(struct Scsi_Host *);
744 extern struct Scsi_Host *scsi_host_get(struct Scsi_Host *);
745 extern int scsi_host_busy(struct Scsi_Host *shost);
746 extern void scsi_host_put(struct Scsi_Host *t);
747 extern struct Scsi_Host *scsi_host_lookup(unsigned short);
748 extern const char *scsi_host_state_name(enum scsi_host_state);
749
750 static inline int __must_check scsi_add_host(struct Scsi_Host *host,
751 struct device *dev)
752 {
753 return scsi_add_host_with_dma(host, dev, dev);
754 }
755
756 static inline struct device *scsi_get_device(struct Scsi_Host *shost)
757 {
758 return shost->shost_gendev.parent;
759 }
760
761 /**
762 * scsi_host_scan_allowed - Is scanning of this host allowed
763 * @shost: Pointer to Scsi_Host.
764 **/
765 static inline int scsi_host_scan_allowed(struct Scsi_Host *shost)
766 {
767 return shost->shost_state == SHOST_RUNNING ||
768 shost->shost_state == SHOST_RECOVERY;
769 }
770
771 extern void scsi_unblock_requests(struct Scsi_Host *);
772 extern void scsi_block_requests(struct Scsi_Host *);
773
774 struct class_container;
775
776 /*
777 * These two functions are used to allocate and free a pseudo device
778 * which will connect to the host adapter itself rather than any
779 * physical device. You must deallocate when you are done with the
780 * thing. This physical pseudo-device isn't real and won't be available
781 * from any high-level drivers.
782 */
783 extern void scsi_free_host_dev(struct scsi_device *);
784 extern struct scsi_device *scsi_get_host_dev(struct Scsi_Host *);
785
786 /*
787 * DIF defines the exchange of protection information between
788 * initiator and SBC block device.
789 *
790 * DIX defines the exchange of protection information between OS and
791 * initiator.
792 */
793 enum scsi_host_prot_capabilities {
794 SHOST_DIF_TYPE1_PROTECTION = 1 << 0, /* T10 DIF Type 1 */
795 SHOST_DIF_TYPE2_PROTECTION = 1 << 1, /* T10 DIF Type 2 */
796 SHOST_DIF_TYPE3_PROTECTION = 1 << 2, /* T10 DIF Type 3 */
797
798 SHOST_DIX_TYPE0_PROTECTION = 1 << 3, /* DIX between OS and HBA only */
799 SHOST_DIX_TYPE1_PROTECTION = 1 << 4, /* DIX with DIF Type 1 */
800 SHOST_DIX_TYPE2_PROTECTION = 1 << 5, /* DIX with DIF Type 2 */
801 SHOST_DIX_TYPE3_PROTECTION = 1 << 6, /* DIX with DIF Type 3 */
802 };
803
804 /*
805 * SCSI hosts which support the Data Integrity Extensions must
806 * indicate their capabilities by setting the prot_capabilities using
807 * this call.
808 */
809 static inline void scsi_host_set_prot(struct Scsi_Host *shost, unsigned int mask)
810 {
811 shost->prot_capabilities = mask;
812 }
813
814 static inline unsigned int scsi_host_get_prot(struct Scsi_Host *shost)
815 {
816 return shost->prot_capabilities;
817 }
818
819 static inline int scsi_host_prot_dma(struct Scsi_Host *shost)
820 {
821 return shost->prot_capabilities >= SHOST_DIX_TYPE0_PROTECTION;
822 }
823
824 static inline unsigned int scsi_host_dif_capable(struct Scsi_Host *shost, unsigned int target_type)
825 {
826 static unsigned char cap[] = { 0,
827 SHOST_DIF_TYPE1_PROTECTION,
828 SHOST_DIF_TYPE2_PROTECTION,
829 SHOST_DIF_TYPE3_PROTECTION };
830
831 if (target_type >= ARRAY_SIZE(cap))
832 return 0;
833
834 return shost->prot_capabilities & cap[target_type] ? target_type : 0;
835 }
836
837 static inline unsigned int scsi_host_dix_capable(struct Scsi_Host *shost, unsigned int target_type)
838 {
839 #if defined(CONFIG_BLK_DEV_INTEGRITY)
840 static unsigned char cap[] = { SHOST_DIX_TYPE0_PROTECTION,
841 SHOST_DIX_TYPE1_PROTECTION,
842 SHOST_DIX_TYPE2_PROTECTION,
843 SHOST_DIX_TYPE3_PROTECTION };
844
845 if (target_type >= ARRAY_SIZE(cap))
846 return 0;
847
848 return shost->prot_capabilities & cap[target_type];
849 #endif
850 return 0;
851 }
852
853 /*
854 * All DIX-capable initiators must support the T10-mandated CRC
855 * checksum. Controllers can optionally implement the IP checksum
856 * scheme which has much lower impact on system performance. Note
857 * that the main rationale for the checksum is to match integrity
858 * metadata with data. Detecting bit errors are a job for ECC memory
859 * and buses.
860 */
861
862 enum scsi_host_guard_type {
863 SHOST_DIX_GUARD_CRC = 1 << 0,
864 SHOST_DIX_GUARD_IP = 1 << 1,
865 };
866
867 static inline void scsi_host_set_guard(struct Scsi_Host *shost, unsigned char type)
868 {
869 shost->prot_guard_type = type;
870 }
871
872 static inline unsigned char scsi_host_get_guard(struct Scsi_Host *shost)
873 {
874 return shost->prot_guard_type;
875 }
876
877 extern int scsi_host_set_state(struct Scsi_Host *, enum scsi_host_state);
878
879 #endif /* _SCSI_SCSI_HOST_H */