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