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1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef _SCSI_SCSI_HOST_H
3#define _SCSI_SCSI_HOST_H
4
5#include <linux/cleanup.h>
6#include <linux/device.h>
7#include <linux/list.h>
8#include <linux/types.h>
9#include <linux/workqueue.h>
10#include <linux/mutex.h>
11#include <linux/seq_file.h>
12#include <linux/blk-mq.h>
13#include <scsi/scsi.h>
14
15struct block_device;
16struct completion;
17struct module;
18struct scsi_cmnd;
19struct scsi_device;
20struct scsi_target;
21struct Scsi_Host;
22struct scsi_transport_template;
23
24
25#define SG_ALL SG_CHUNK_SIZE
26
27#define MODE_UNKNOWN 0x00
28#define MODE_INITIATOR 0x01
29#define MODE_TARGET 0x02
30
31/**
32 * enum scsi_timeout_action - How to handle a command that timed out.
33 * @SCSI_EH_DONE: The command has already been completed.
34 * @SCSI_EH_RESET_TIMER: Reset the timer and continue waiting for completion.
35 * @SCSI_EH_NOT_HANDLED: The command has not yet finished. Abort the command.
36 */
37enum scsi_timeout_action {
38 SCSI_EH_DONE,
39 SCSI_EH_RESET_TIMER,
40 SCSI_EH_NOT_HANDLED,
41};
42
43struct scsi_host_template {
44 /*
45 * Put fields referenced in IO submission path together in
46 * same cacheline
47 */
48
49 /*
50 * Additional per-command data allocated for the driver.
51 */
52 unsigned int cmd_size;
53
54 /*
55 * The queuecommand function is used to queue up a scsi
56 * command block to the LLDD. When the driver finished
57 * processing the command the done callback is invoked.
58 *
59 * If queuecommand returns 0, then the driver has accepted the
60 * command. It must also push it to the HBA if the scsi_cmnd
61 * flag SCMD_LAST is set, or if the driver does not implement
62 * commit_rqs. The done() function must be called on the command
63 * when the driver has finished with it. (you may call done on the
64 * command before queuecommand returns, but in this case you
65 * *must* return 0 from queuecommand).
66 *
67 * Queuecommand may also reject the command, in which case it may
68 * not touch the command and must not call done() for it.
69 *
70 * There are two possible rejection returns:
71 *
72 * SCSI_MLQUEUE_DEVICE_BUSY: Block this device temporarily, but
73 * allow commands to other devices serviced by this host.
74 *
75 * SCSI_MLQUEUE_HOST_BUSY: Block all devices served by this
76 * host temporarily.
77 *
78 * For compatibility, any other non-zero return is treated the
79 * same as SCSI_MLQUEUE_HOST_BUSY.
80 *
81 * NOTE: "temporarily" means either until the next command for#
82 * this device/host completes, or a period of time determined by
83 * I/O pressure in the system if there are no other outstanding
84 * commands.
85 *
86 * STATUS: REQUIRED
87 */
88 enum scsi_qc_status (*queuecommand)(struct Scsi_Host *,
89 struct scsi_cmnd *);
90
91 /*
92 * Queue a reserved command (BLK_MQ_REQ_RESERVED). The .queuecommand()
93 * documentation also applies to the .queue_reserved_command() callback.
94 */
95 enum scsi_qc_status (*queue_reserved_command)(struct Scsi_Host *,
96 struct scsi_cmnd *);
97
98 /*
99 * The commit_rqs function is used to trigger a hardware
100 * doorbell after some requests have been queued with
101 * queuecommand, when an error is encountered before sending
102 * the request with SCMD_LAST set.
103 *
104 * STATUS: OPTIONAL
105 */
106 void (*commit_rqs)(struct Scsi_Host *, u16);
107
108 struct module *module;
109 const char *name;
110
111 /*
112 * The info function will return whatever useful information the
113 * developer sees fit. If not provided, then the name field will
114 * be used instead.
115 *
116 * Status: OPTIONAL
117 */
118 const char *(*info)(struct Scsi_Host *);
119
120 /*
121 * Ioctl interface
122 *
123 * Status: OPTIONAL
124 */
125 int (*ioctl)(struct scsi_device *dev, unsigned int cmd,
126 void __user *arg);
127
128
129#ifdef CONFIG_COMPAT
130 /*
131 * Compat handler. Handle 32bit ABI.
132 * When unknown ioctl is passed return -ENOIOCTLCMD.
133 *
134 * Status: OPTIONAL
135 */
136 int (*compat_ioctl)(struct scsi_device *dev, unsigned int cmd,
137 void __user *arg);
138#endif
139
140 int (*init_cmd_priv)(struct Scsi_Host *shost, struct scsi_cmnd *cmd);
141 int (*exit_cmd_priv)(struct Scsi_Host *shost, struct scsi_cmnd *cmd);
142
143 /*
144 * This is an error handling strategy routine. You don't need to
145 * define one of these if you don't want to - there is a default
146 * routine that is present that should work in most cases. For those
147 * driver authors that have the inclination and ability to write their
148 * own strategy routine, this is where it is specified. Note - the
149 * strategy routine is *ALWAYS* run in the context of the kernel eh
150 * thread. Thus you are guaranteed to *NOT* be in an interrupt
151 * handler when you execute this, and you are also guaranteed to
152 * *NOT* have any other commands being queued while you are in the
153 * strategy routine. When you return from this function, operations
154 * return to normal.
155 *
156 * See scsi_error.c scsi_unjam_host for additional comments about
157 * what this function should and should not be attempting to do.
158 *
159 * Status: REQUIRED (at least one of them)
160 */
161 int (* eh_abort_handler)(struct scsi_cmnd *);
162 int (* eh_device_reset_handler)(struct scsi_cmnd *);
163 int (* eh_target_reset_handler)(struct scsi_cmnd *);
164 int (* eh_bus_reset_handler)(struct scsi_cmnd *);
165 int (* eh_host_reset_handler)(struct scsi_cmnd *);
166
167 /*
168 * Before the mid layer attempts to scan for a new device where none
169 * currently exists, it will call this entry in your driver. Should
170 * your driver need to allocate any structs or perform any other init
171 * items in order to send commands to a currently unused target/lun
172 * combo, then this is where you can perform those allocations. This
173 * is specifically so that drivers won't have to perform any kind of
174 * "is this a new device" checks in their queuecommand routine,
175 * thereby making the hot path a bit quicker.
176 *
177 * Return values: 0 on success, non-0 on failure
178 *
179 * Deallocation: If we didn't find any devices at this ID, you will
180 * get an immediate call to sdev_destroy(). If we find something
181 * here then you will get a call to sdev_configure(), then the
182 * device will be used for however long it is kept around, then when
183 * the device is removed from the system (or * possibly at reboot
184 * time), you will then get a call to sdev_destroy(). This is
185 * assuming you implement sdev_configure and sdev_destroy.
186 * However, if you allocate memory and hang it off the device struct,
187 * then you must implement the sdev_destroy() routine at a minimum
188 * in order to avoid leaking memory
189 * each time a device is tore down.
190 *
191 * Status: OPTIONAL
192 */
193 int (* sdev_init)(struct scsi_device *);
194
195 /*
196 * Once the device has responded to an INQUIRY and we know the
197 * device is online, we call into the low level driver with the
198 * struct scsi_device *. If the low level device driver implements
199 * this function, it *must* perform the task of setting the queue
200 * depth on the device. All other tasks are optional and depend
201 * on what the driver supports and various implementation details.
202 *
203 * Things currently recommended to be handled at this time include:
204 *
205 * 1. Setting the device queue depth. Proper setting of this is
206 * described in the comments for scsi_change_queue_depth.
207 * 2. Determining if the device supports the various synchronous
208 * negotiation protocols. The device struct will already have
209 * responded to INQUIRY and the results of the standard items
210 * will have been shoved into the various device flag bits, eg.
211 * device->sdtr will be true if the device supports SDTR messages.
212 * 3. Allocating command structs that the device will need.
213 * 4. Setting the default timeout on this device (if needed).
214 * 5. Anything else the low level driver might want to do on a device
215 * specific setup basis...
216 * 6. Return 0 on success, non-0 on error. The device will be marked
217 * as offline on error so that no access will occur. If you return
218 * non-0, your sdev_destroy routine will never get called for this
219 * device, so don't leave any loose memory hanging around, clean
220 * up after yourself before returning non-0
221 *
222 * Status: OPTIONAL
223 */
224 int (* sdev_configure)(struct scsi_device *, struct queue_limits *lim);
225
226 /*
227 * Immediately prior to deallocating the device and after all activity
228 * has ceased the mid layer calls this point so that the low level
229 * driver may completely detach itself from the scsi device and vice
230 * versa. The low level driver is responsible for freeing any memory
231 * it allocated in the sdev_init or sdev_configure calls.
232 *
233 * Status: OPTIONAL
234 */
235 void (* sdev_destroy)(struct scsi_device *);
236
237 /*
238 * Before the mid layer attempts to scan for a new device attached
239 * to a target where no target currently exists, it will call this
240 * entry in your driver. Should your driver need to allocate any
241 * structs or perform any other init items in order to send commands
242 * to a currently unused target, then this is where you can perform
243 * those allocations.
244 *
245 * Return values: 0 on success, non-0 on failure
246 *
247 * Status: OPTIONAL
248 */
249 int (* target_alloc)(struct scsi_target *);
250
251 /*
252 * Immediately prior to deallocating the target structure, and
253 * after all activity to attached scsi devices has ceased, the
254 * midlayer calls this point so that the driver may deallocate
255 * and terminate any references to the target.
256 *
257 * Note: This callback is called with the host lock held and hence
258 * must not sleep.
259 *
260 * Status: OPTIONAL
261 */
262 void (* target_destroy)(struct scsi_target *);
263
264 /*
265 * If a host has the ability to discover targets on its own instead
266 * of scanning the entire bus, it can fill in this function and
267 * call scsi_scan_host(). This function will be called periodically
268 * until it returns 1 with the scsi_host and the elapsed time of
269 * the scan in jiffies.
270 *
271 * Status: OPTIONAL
272 */
273 int (* scan_finished)(struct Scsi_Host *, unsigned long);
274
275 /*
276 * If the host wants to be called before the scan starts, but
277 * after the midlayer has set up ready for the scan, it can fill
278 * in this function.
279 *
280 * Status: OPTIONAL
281 */
282 void (* scan_start)(struct Scsi_Host *);
283
284 /*
285 * Fill in this function to allow the queue depth of this host
286 * to be changeable (on a per device basis). Returns either
287 * the current queue depth setting (may be different from what
288 * was passed in) or an error. An error should only be
289 * returned if the requested depth is legal but the driver was
290 * unable to set it. If the requested depth is illegal, the
291 * driver should set and return the closest legal queue depth.
292 *
293 * Status: OPTIONAL
294 */
295 int (* change_queue_depth)(struct scsi_device *, int);
296
297 /*
298 * This functions lets the driver expose the queue mapping
299 * to the block layer.
300 *
301 * Status: OPTIONAL
302 */
303 void (* map_queues)(struct Scsi_Host *shost);
304
305 /*
306 * SCSI interface of blk_poll - poll for IO completions.
307 * Only applicable if SCSI LLD exposes multiple h/w queues.
308 *
309 * Return value: Number of completed entries found.
310 *
311 * Status: OPTIONAL
312 */
313 int (* mq_poll)(struct Scsi_Host *shost, unsigned int queue_num);
314
315 /*
316 * Check if scatterlists need to be padded for DMA draining.
317 *
318 * Status: OPTIONAL
319 */
320 bool (* dma_need_drain)(struct request *rq);
321
322 /*
323 * This function determines the BIOS parameters for a given
324 * harddisk. These tend to be numbers that are made up by
325 * the host adapter. Parameters:
326 * size, device, list (heads, sectors, cylinders)
327 *
328 * Status: OPTIONAL
329 */
330 int (* bios_param)(struct scsi_device *, struct gendisk *,
331 sector_t, int []);
332
333 /*
334 * This function is called when one or more partitions on the
335 * device reach beyond the end of the device.
336 *
337 * Status: OPTIONAL
338 */
339 void (*unlock_native_capacity)(struct scsi_device *);
340
341 /*
342 * Can be used to export driver statistics and other infos to the
343 * world outside the kernel ie. userspace and it also provides an
344 * interface to feed the driver with information.
345 *
346 * Status: OBSOLETE
347 */
348 int (*show_info)(struct seq_file *, struct Scsi_Host *);
349 int (*write_info)(struct Scsi_Host *, char *, int);
350
351 /*
352 * This is an optional routine that allows the transport to become
353 * involved when a scsi io timer fires. The return value tells the
354 * timer routine how to finish the io timeout handling.
355 *
356 * Status: OPTIONAL
357 */
358 enum scsi_timeout_action (*eh_timed_out)(struct scsi_cmnd *);
359 /*
360 * Optional routine that allows the transport to decide if a cmd
361 * is retryable. Return true if the transport is in a state the
362 * cmd should be retried on.
363 */
364 bool (*eh_should_retry_cmd)(struct scsi_cmnd *scmd);
365
366 /* This is an optional routine that allows transport to initiate
367 * LLD adapter or firmware reset using sysfs attribute.
368 *
369 * Return values: 0 on success, -ve value on failure.
370 *
371 * Status: OPTIONAL
372 */
373
374 int (*host_reset)(struct Scsi_Host *shost, int reset_type);
375#define SCSI_ADAPTER_RESET 1
376#define SCSI_FIRMWARE_RESET 2
377
378
379 /*
380 * Name of proc directory
381 */
382 const char *proc_name;
383
384 /*
385 * This determines if we will use a non-interrupt driven
386 * or an interrupt driven scheme. It is set to the maximum number
387 * of simultaneous commands a single hw queue in HBA will accept
388 * excluding internal commands.
389 */
390 int can_queue;
391
392 /*
393 * This determines how many commands the HBA will set aside
394 * for internal commands. This number will be added to
395 * @can_queue to calculate the maximum number of simultaneous
396 * commands sent to the host.
397 */
398 int nr_reserved_cmds;
399
400 /*
401 * In many instances, especially where disconnect / reconnect are
402 * supported, our host also has an ID on the SCSI bus. If this is
403 * the case, then it must be reserved. Please set this_id to -1 if
404 * your setup is in single initiator mode, and the host lacks an
405 * ID.
406 */
407 int this_id;
408
409 /*
410 * This determines the degree to which the host adapter is capable
411 * of scatter-gather.
412 */
413 unsigned short sg_tablesize;
414 unsigned short sg_prot_tablesize;
415
416 /*
417 * Set this if the host adapter has limitations beside segment count.
418 */
419 unsigned int max_sectors;
420
421 /*
422 * Maximum size in bytes of a single segment.
423 */
424 unsigned int max_segment_size;
425
426 unsigned int dma_alignment;
427
428 /*
429 * DMA scatter gather segment boundary limit. A segment crossing this
430 * boundary will be split in two.
431 */
432 unsigned long dma_boundary;
433
434 unsigned long virt_boundary_mask;
435
436 /*
437 * This specifies "machine infinity" for host templates which don't
438 * limit the transfer size. Note this limit represents an absolute
439 * maximum, and may be over the transfer limits allowed for
440 * individual devices (e.g. 256 for SCSI-1).
441 */
442#define SCSI_DEFAULT_MAX_SECTORS 1024
443
444 /*
445 * True if this host adapter can make good use of linked commands.
446 * This will allow more than one command to be queued to a given
447 * unit on a given host. Set this to the maximum number of command
448 * blocks to be provided for each device. Set this to 1 for one
449 * command block per lun, 2 for two, etc. Do not set this to 0.
450 * You should make sure that the host adapter will do the right thing
451 * before you try setting this above 1.
452 */
453 short cmd_per_lun;
454
455 /*
456 * Allocate tags starting from last allocated tag.
457 */
458 bool tag_alloc_policy_rr : 1;
459
460 /*
461 * Track QUEUE_FULL events and reduce queue depth on demand.
462 */
463 unsigned track_queue_depth:1;
464
465 /*
466 * This specifies the mode that a LLD supports.
467 */
468 unsigned supported_mode:2;
469
470 /*
471 * True for emulated SCSI host adapters (e.g. ATAPI).
472 */
473 unsigned emulated:1;
474
475 /*
476 * True if the low-level driver performs its own reset-settle delays.
477 */
478 unsigned skip_settle_delay:1;
479
480 /* True if the controller does not support WRITE SAME */
481 unsigned no_write_same:1;
482
483 /* True if the host uses host-wide tagspace */
484 unsigned host_tagset:1;
485
486 /* The queuecommand callback may block. See also BLK_MQ_F_BLOCKING. */
487 unsigned queuecommand_may_block:1;
488
489 /*
490 * Countdown for host blocking with no commands outstanding.
491 */
492 unsigned int max_host_blocked;
493
494 /*
495 * Default value for the blocking. If the queue is empty,
496 * host_blocked counts down in the request_fn until it restarts
497 * host operations as zero is reached.
498 *
499 * FIXME: This should probably be a value in the template
500 */
501#define SCSI_DEFAULT_HOST_BLOCKED 7
502
503 /*
504 * Pointer to the SCSI host sysfs attribute groups, NULL terminated.
505 */
506 const struct attribute_group **shost_groups;
507
508 /*
509 * Pointer to the SCSI device attribute groups for this host,
510 * NULL terminated.
511 */
512 const struct attribute_group **sdev_groups;
513
514 /*
515 * Vendor Identifier associated with the host
516 *
517 * Note: When specifying vendor_id, be sure to read the
518 * Vendor Type and ID formatting requirements specified in
519 * scsi_netlink.h
520 */
521 u64 vendor_id;
522};
523
524/*
525 * Temporary #define for host lock push down. Can be removed when all
526 * drivers have been updated to take advantage of unlocked
527 * queuecommand.
528 *
529 */
530#define DEF_SCSI_QCMD(func_name) \
531 enum scsi_qc_status func_name(struct Scsi_Host *shost, \
532 struct scsi_cmnd *cmd) \
533 { \
534 unsigned long irq_flags; \
535 enum scsi_qc_status rc; \
536 \
537 spin_lock_irqsave(shost->host_lock, irq_flags); \
538 rc = func_name##_lck(cmd); \
539 spin_unlock_irqrestore(shost->host_lock, irq_flags); \
540 return rc; \
541 }
542
543
544/*
545 * shost state: If you alter this, you also need to alter scsi_sysfs.c
546 * (for the ascii descriptions) and the state model enforcer:
547 * scsi_host_set_state()
548 */
549enum scsi_host_state {
550 SHOST_CREATED = 1,
551 SHOST_RUNNING,
552 SHOST_CANCEL,
553 SHOST_DEL,
554 SHOST_RECOVERY,
555 SHOST_CANCEL_RECOVERY,
556 SHOST_DEL_RECOVERY,
557};
558
559struct Scsi_Host {
560 /*
561 * __devices is protected by the host_lock, but you should
562 * usually use scsi_device_lookup / shost_for_each_device
563 * to access it and don't care about locking yourself.
564 * In the rare case of being in irq context you can use
565 * their __ prefixed variants with the lock held. NEVER
566 * access this list directly from a driver.
567 */
568 struct list_head __devices;
569 struct list_head __targets;
570
571 struct list_head starved_list;
572
573 spinlock_t default_lock;
574 spinlock_t *host_lock;
575
576 struct mutex scan_mutex;/* serialize scanning activity */
577
578 struct list_head eh_abort_list;
579 struct list_head eh_cmd_q;
580 struct task_struct * ehandler; /* Error recovery thread. */
581 struct completion * eh_action; /* Wait for specific actions on the
582 host. */
583 wait_queue_head_t host_wait;
584 const struct scsi_host_template *hostt;
585 struct scsi_transport_template *transportt;
586
587 struct kref tagset_refcnt;
588 struct completion tagset_freed;
589 /* Area to keep a shared tag map */
590 struct blk_mq_tag_set tag_set;
591
592 atomic_t host_blocked;
593
594 unsigned int host_failed; /* commands that failed.
595 protected by host_lock */
596 unsigned int host_eh_scheduled; /* EH scheduled without command */
597
598 unsigned int host_no; /* Used for IOCTL_GET_IDLUN, /proc/scsi et al. */
599
600 /* next two fields are used to bound the time spent in error handling */
601 int eh_deadline;
602 unsigned long last_reset;
603
604
605 /*
606 * These three parameters can be used to allow for wide scsi,
607 * and for host adapters that support multiple busses
608 * The last two should be set to 1 more than the actual max id
609 * or lun (e.g. 8 for SCSI parallel systems).
610 */
611 unsigned int max_channel;
612 unsigned int max_id;
613 u64 max_lun;
614
615 /*
616 * This is a unique identifier that must be assigned so that we
617 * have some way of identifying each detected host adapter properly
618 * and uniquely. For hosts that do not support more than one card
619 * in the system at one time, this does not need to be set. It is
620 * initialized to 0 in scsi_host_alloc.
621 */
622 unsigned int unique_id;
623
624 /*
625 * The maximum length of SCSI commands that this host can accept.
626 * Probably 12 for most host adapters, but could be 16 for others.
627 * or 260 if the driver supports variable length cdbs.
628 * For drivers that don't set this field, a value of 12 is
629 * assumed.
630 */
631 unsigned short max_cmd_len;
632
633 int this_id;
634
635 /*
636 * Number of commands this host can handle at the same time.
637 * This excludes reserved commands as specified by nr_reserved_cmds.
638 */
639 int can_queue;
640 /*
641 * Number of reserved commands to allocate, if any.
642 */
643 unsigned int nr_reserved_cmds;
644
645 short cmd_per_lun;
646 short unsigned int sg_tablesize;
647 short unsigned int sg_prot_tablesize;
648 unsigned int max_sectors;
649 unsigned int opt_sectors;
650 unsigned int max_segment_size;
651 unsigned int dma_alignment;
652 unsigned long dma_boundary;
653 unsigned long virt_boundary_mask;
654 /*
655 * In scsi-mq mode, the number of hardware queues supported by the LLD.
656 *
657 * Note: it is assumed that each hardware queue has a queue depth of
658 * can_queue. In other words, the total queue depth per host
659 * is nr_hw_queues * can_queue. However, for when host_tagset is set,
660 * the total queue depth is can_queue.
661 */
662 unsigned nr_hw_queues;
663 unsigned nr_maps;
664
665 /* Asynchronous scan in progress */
666 bool async_scan __guarded_by(&scan_mutex);
667
668 /* Don't resume host in EH */
669 bool eh_noresume;
670
671 unsigned active_mode:2;
672
673 /*
674 * Host has requested that no further requests come through for the
675 * time being.
676 */
677 unsigned host_self_blocked:1;
678
679 /*
680 * Host uses correct SCSI ordering not PC ordering. The bit is
681 * set for the minority of drivers whose authors actually read
682 * the spec ;).
683 */
684 unsigned reverse_ordering:1;
685
686 /* Task mgmt function in progress */
687 unsigned tmf_in_progress:1;
688
689 /* The controller does not support WRITE SAME */
690 unsigned no_write_same:1;
691
692 /* True if the host uses host-wide tagspace */
693 unsigned host_tagset:1;
694
695 /* The queuecommand callback may block. See also BLK_MQ_F_BLOCKING. */
696 unsigned queuecommand_may_block:1;
697
698 /* Host responded with short (<36 bytes) INQUIRY result */
699 unsigned short_inquiry:1;
700
701 /* The transport requires the LUN bits NOT to be stored in CDB[1] */
702 unsigned no_scsi2_lun_in_cdb:1;
703
704 /*
705 * Optional work queue to be utilized by the transport
706 */
707 struct workqueue_struct *work_q;
708
709 /*
710 * Task management function work queue
711 */
712 struct workqueue_struct *tmf_work_q;
713
714 /*
715 * Value host_blocked counts down from
716 */
717 unsigned int max_host_blocked;
718
719 /* Protection Information */
720 unsigned int prot_capabilities;
721 unsigned char prot_guard_type;
722
723 /* legacy crap */
724 unsigned long base;
725 unsigned long io_port;
726 unsigned char n_io_port;
727 unsigned char dma_channel;
728 unsigned int irq;
729
730
731 enum scsi_host_state shost_state __guarded_by(host_lock);
732
733 /* ldm bits */
734 struct device shost_gendev, shost_dev;
735
736 /*
737 * A SCSI device structure used for sending internal commands to the
738 * HBA. There is no corresponding logical unit inside the SCSI device.
739 */
740 struct scsi_device *pseudo_sdev;
741
742 /*
743 * Points to the transport data (if any) which is allocated
744 * separately
745 */
746 void *shost_data;
747
748 /*
749 * Points to the physical bus device we'd use to do DMA
750 * Needed just in case we have virtual hosts.
751 */
752 struct device *dma_dev;
753
754 /* Used for an rcu-synchronizing eh wakeup */
755 struct work_struct eh_work;
756
757 /* Delay for runtime autosuspend */
758 int rpm_autosuspend_delay;
759
760 /*
761 * We should ensure that this is aligned, both for better performance
762 * and also because some compilers (m68k) don't automatically force
763 * alignment to a long boundary.
764 */
765 unsigned long hostdata[] /* Used for storage of host specific stuff */
766 __attribute__ ((aligned (sizeof(unsigned long))));
767};
768
769#define class_to_shost(d) \
770 container_of(d, struct Scsi_Host, shost_dev)
771
772#define shost_printk(prefix, shost, fmt, a...) \
773 dev_printk(prefix, &(shost)->shost_gendev, fmt, ##a)
774
775static inline void *shost_priv(struct Scsi_Host *shost)
776{
777 return (void *)shost->hostdata;
778}
779
780int scsi_is_host_device(const struct device *);
781
782static inline struct Scsi_Host *dev_to_shost(struct device *dev)
783{
784 while (!scsi_is_host_device(dev)) {
785 if (!dev->parent)
786 return NULL;
787 dev = dev->parent;
788 }
789 return container_of(dev, struct Scsi_Host, shost_gendev);
790}
791
792static inline enum scsi_host_state scsi_get_host_state(struct Scsi_Host *shost)
793{
794 return context_unsafe(READ_ONCE(shost->shost_state));
795}
796
797static inline int scsi_host_in_recovery(struct Scsi_Host *shost)
798{
799 enum scsi_host_state state = scsi_get_host_state(shost);
800
801 return state == SHOST_RECOVERY ||
802 state == SHOST_CANCEL_RECOVERY ||
803 state == SHOST_DEL_RECOVERY ||
804 shost->tmf_in_progress;
805}
806
807extern int scsi_queue_work(struct Scsi_Host *, struct work_struct *);
808extern void scsi_flush_work(struct Scsi_Host *);
809
810extern struct Scsi_Host *scsi_host_alloc(const struct scsi_host_template *, int);
811extern int __must_check scsi_add_host_with_dma(struct Scsi_Host *,
812 struct device *,
813 struct device *);
814#if defined(CONFIG_SCSI_PROC_FS)
815struct proc_dir_entry *
816scsi_template_proc_dir(const struct scsi_host_template *sht);
817#else
818#define scsi_template_proc_dir(sht) NULL
819#endif
820extern void scsi_scan_host(struct Scsi_Host *);
821extern int scsi_resume_device(struct scsi_device *sdev);
822extern int scsi_rescan_device(struct scsi_device *sdev);
823extern void scsi_remove_host(struct Scsi_Host *);
824extern struct Scsi_Host *scsi_host_get(struct Scsi_Host *);
825extern int scsi_host_busy(struct Scsi_Host *shost);
826extern void scsi_host_put(struct Scsi_Host *t);
827extern struct Scsi_Host *scsi_host_lookup(unsigned int hostnum);
828extern const char *scsi_host_state_name(enum scsi_host_state);
829extern void scsi_host_complete_all_commands(struct Scsi_Host *shost,
830 enum scsi_host_status status);
831
832static inline int __must_check scsi_add_host(struct Scsi_Host *host,
833 struct device *dev)
834{
835 return scsi_add_host_with_dma(host, dev, dev);
836}
837
838static inline struct device *scsi_get_device(struct Scsi_Host *shost)
839{
840 return shost->shost_gendev.parent;
841}
842
843/**
844 * scsi_host_scan_allowed - Is scanning of this host allowed
845 * @shost: Pointer to Scsi_Host.
846 **/
847static inline int scsi_host_scan_allowed(struct Scsi_Host *shost)
848{
849 enum scsi_host_state state = scsi_get_host_state(shost);
850
851 return state == SHOST_RUNNING || state == SHOST_RECOVERY;
852}
853
854extern void scsi_unblock_requests(struct Scsi_Host *);
855extern void scsi_block_requests(struct Scsi_Host *);
856extern int scsi_host_block(struct Scsi_Host *shost);
857extern int scsi_host_unblock(struct Scsi_Host *shost, int new_state);
858
859void scsi_host_busy_iter(struct Scsi_Host *,
860 bool (*fn)(struct scsi_cmnd *, void *), void *priv);
861
862struct class_container;
863
864/*
865 * DIF defines the exchange of protection information between
866 * initiator and SBC block device.
867 *
868 * DIX defines the exchange of protection information between OS and
869 * initiator.
870 */
871enum scsi_host_prot_capabilities {
872 SHOST_DIF_TYPE1_PROTECTION = 1 << 0, /* T10 DIF Type 1 */
873 SHOST_DIF_TYPE2_PROTECTION = 1 << 1, /* T10 DIF Type 2 */
874 SHOST_DIF_TYPE3_PROTECTION = 1 << 2, /* T10 DIF Type 3 */
875
876 SHOST_DIX_TYPE0_PROTECTION = 1 << 3, /* DIX between OS and HBA only */
877 SHOST_DIX_TYPE1_PROTECTION = 1 << 4, /* DIX with DIF Type 1 */
878 SHOST_DIX_TYPE2_PROTECTION = 1 << 5, /* DIX with DIF Type 2 */
879 SHOST_DIX_TYPE3_PROTECTION = 1 << 6, /* DIX with DIF Type 3 */
880};
881
882/*
883 * SCSI hosts which support the Data Integrity Extensions must
884 * indicate their capabilities by setting the prot_capabilities using
885 * this call.
886 */
887static inline void scsi_host_set_prot(struct Scsi_Host *shost, unsigned int mask)
888{
889 shost->prot_capabilities = mask;
890}
891
892static inline unsigned int scsi_host_get_prot(struct Scsi_Host *shost)
893{
894 return shost->prot_capabilities;
895}
896
897static inline int scsi_host_prot_dma(struct Scsi_Host *shost)
898{
899 return shost->prot_capabilities >= SHOST_DIX_TYPE0_PROTECTION;
900}
901
902static inline unsigned int scsi_host_dif_capable(struct Scsi_Host *shost, unsigned int target_type)
903{
904 static unsigned char cap[] = { 0,
905 SHOST_DIF_TYPE1_PROTECTION,
906 SHOST_DIF_TYPE2_PROTECTION,
907 SHOST_DIF_TYPE3_PROTECTION };
908
909 if (target_type >= ARRAY_SIZE(cap))
910 return 0;
911
912 return shost->prot_capabilities & cap[target_type] ? target_type : 0;
913}
914
915static inline unsigned int scsi_host_dix_capable(struct Scsi_Host *shost, unsigned int target_type)
916{
917#if defined(CONFIG_BLK_DEV_INTEGRITY)
918 static unsigned char cap[] = { SHOST_DIX_TYPE0_PROTECTION,
919 SHOST_DIX_TYPE1_PROTECTION,
920 SHOST_DIX_TYPE2_PROTECTION,
921 SHOST_DIX_TYPE3_PROTECTION };
922
923 if (target_type >= ARRAY_SIZE(cap))
924 return 0;
925
926 return shost->prot_capabilities & cap[target_type];
927#endif
928 return 0;
929}
930
931/*
932 * All DIX-capable initiators must support the T10-mandated CRC
933 * checksum. Controllers can optionally implement the IP checksum
934 * scheme which has much lower impact on system performance. Note
935 * that the main rationale for the checksum is to match integrity
936 * metadata with data. Detecting bit errors are a job for ECC memory
937 * and buses.
938 */
939
940enum scsi_host_guard_type {
941 SHOST_DIX_GUARD_CRC = 1 << 0,
942 SHOST_DIX_GUARD_IP = 1 << 1,
943};
944
945static inline void scsi_host_set_guard(struct Scsi_Host *shost, unsigned char type)
946{
947 shost->prot_guard_type = type;
948}
949
950static inline unsigned char scsi_host_get_guard(struct Scsi_Host *shost)
951{
952 return shost->prot_guard_type;
953}
954
955int scsi_host_set_state(struct Scsi_Host *shost, enum scsi_host_state state)
956 __must_hold(shost->host_lock);
957
958#endif /* _SCSI_SCSI_HOST_H */