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