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