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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 * Status: OPTIONAL
249 */
250 void (* target_destroy)(struct scsi_target *);
251
252 /*
253 * If a host has the ability to discover targets on its own instead
254 * of scanning the entire bus, it can fill in this function and
255 * call scsi_scan_host(). This function will be called periodically
256 * until it returns 1 with the scsi_host and the elapsed time of
257 * the scan in jiffies.
258 *
259 * Status: OPTIONAL
260 */
261 int (* scan_finished)(struct Scsi_Host *, unsigned long);
262
263 /*
264 * If the host wants to be called before the scan starts, but
265 * after the midlayer has set up ready for the scan, it can fill
266 * in this function.
267 *
268 * Status: OPTIONAL
269 */
270 void (* scan_start)(struct Scsi_Host *);
271
272 /*
273 * Fill in this function to allow the queue depth of this host
274 * to be changeable (on a per device basis). Returns either
275 * the current queue depth setting (may be different from what
276 * was passed in) or an error. An error should only be
277 * returned if the requested depth is legal but the driver was
278 * unable to set it. If the requested depth is illegal, the
279 * driver should set and return the closest legal queue depth.
280 *
281 * Status: OPTIONAL
282 */
283 int (* change_queue_depth)(struct scsi_device *, int);
284
285 /*
286 * This functions lets the driver expose the queue mapping
287 * to the block layer.
288 *
289 * Status: OPTIONAL
290 */
291 void (* map_queues)(struct Scsi_Host *shost);
292
293 /*
294 * SCSI interface of blk_poll - poll for IO completions.
295 * Only applicable if SCSI LLD exposes multiple h/w queues.
296 *
297 * Return value: Number of completed entries found.
298 *
299 * Status: OPTIONAL
300 */
301 int (* mq_poll)(struct Scsi_Host *shost, unsigned int queue_num);
302
303 /*
304 * Check if scatterlists need to be padded for DMA draining.
305 *
306 * Status: OPTIONAL
307 */
308 bool (* dma_need_drain)(struct request *rq);
309
310 /*
311 * This function determines the BIOS parameters for a given
312 * harddisk. These tend to be numbers that are made up by
313 * the host adapter. Parameters:
314 * size, device, list (heads, sectors, cylinders)
315 *
316 * Status: OPTIONAL
317 */
318 int (* bios_param)(struct scsi_device *, struct block_device *,
319 sector_t, int []);
320
321 /*
322 * This function is called when one or more partitions on the
323 * device reach beyond the end of the device.
324 *
325 * Status: OPTIONAL
326 */
327 void (*unlock_native_capacity)(struct scsi_device *);
328
329 /*
330 * Can be used to export driver statistics and other infos to the
331 * world outside the kernel ie. userspace and it also provides an
332 * interface to feed the driver with information.
333 *
334 * Status: OBSOLETE
335 */
336 int (*show_info)(struct seq_file *, struct Scsi_Host *);
337 int (*write_info)(struct Scsi_Host *, char *, int);
338
339 /*
340 * This is an optional routine that allows the transport to become
341 * involved when a scsi io timer fires. The return value tells the
342 * timer routine how to finish the io timeout handling.
343 *
344 * Status: OPTIONAL
345 */
346 enum scsi_timeout_action (*eh_timed_out)(struct scsi_cmnd *);
347 /*
348 * Optional routine that allows the transport to decide if a cmd
349 * is retryable. Return true if the transport is in a state the
350 * cmd should be retried on.
351 */
352 bool (*eh_should_retry_cmd)(struct scsi_cmnd *scmd);
353
354 /* This is an optional routine that allows transport to initiate
355 * LLD adapter or firmware reset using sysfs attribute.
356 *
357 * Return values: 0 on success, -ve value on failure.
358 *
359 * Status: OPTIONAL
360 */
361
362 int (*host_reset)(struct Scsi_Host *shost, int reset_type);
363#define SCSI_ADAPTER_RESET 1
364#define SCSI_FIRMWARE_RESET 2
365
366
367 /*
368 * Name of proc directory
369 */
370 const char *proc_name;
371
372 /*
373 * This determines if we will use a non-interrupt driven
374 * or an interrupt driven scheme. It is set to the maximum number
375 * of simultaneous commands a single hw queue in HBA will accept.
376 */
377 int can_queue;
378
379 /*
380 * In many instances, especially where disconnect / reconnect are
381 * supported, our host also has an ID on the SCSI bus. If this is
382 * the case, then it must be reserved. Please set this_id to -1 if
383 * your setup is in single initiator mode, and the host lacks an
384 * ID.
385 */
386 int this_id;
387
388 /*
389 * This determines the degree to which the host adapter is capable
390 * of scatter-gather.
391 */
392 unsigned short sg_tablesize;
393 unsigned short sg_prot_tablesize;
394
395 /*
396 * Set this if the host adapter has limitations beside segment count.
397 */
398 unsigned int max_sectors;
399
400 /*
401 * Maximum size in bytes of a single segment.
402 */
403 unsigned int max_segment_size;
404
405 /*
406 * DMA scatter gather segment boundary limit. A segment crossing this
407 * boundary will be split in two.
408 */
409 unsigned long dma_boundary;
410
411 unsigned long virt_boundary_mask;
412
413 /*
414 * This specifies "machine infinity" for host templates which don't
415 * limit the transfer size. Note this limit represents an absolute
416 * maximum, and may be over the transfer limits allowed for
417 * individual devices (e.g. 256 for SCSI-1).
418 */
419#define SCSI_DEFAULT_MAX_SECTORS 1024
420
421 /*
422 * True if this host adapter can make good use of linked commands.
423 * This will allow more than one command to be queued to a given
424 * unit on a given host. Set this to the maximum number of command
425 * blocks to be provided for each device. Set this to 1 for one
426 * command block per lun, 2 for two, etc. Do not set this to 0.
427 * You should make sure that the host adapter will do the right thing
428 * before you try setting this above 1.
429 */
430 short cmd_per_lun;
431
432 /* If use block layer to manage tags, this is tag allocation policy */
433 int tag_alloc_policy;
434
435 /*
436 * Track QUEUE_FULL events and reduce queue depth on demand.
437 */
438 unsigned track_queue_depth:1;
439
440 /*
441 * This specifies the mode that a LLD supports.
442 */
443 unsigned supported_mode:2;
444
445 /*
446 * True for emulated SCSI host adapters (e.g. ATAPI).
447 */
448 unsigned emulated:1;
449
450 /*
451 * True if the low-level driver performs its own reset-settle delays.
452 */
453 unsigned skip_settle_delay:1;
454
455 /* True if the controller does not support WRITE SAME */
456 unsigned no_write_same:1;
457
458 /* True if the host uses host-wide tagspace */
459 unsigned host_tagset:1;
460
461 /*
462 * Countdown for host blocking with no commands outstanding.
463 */
464 unsigned int max_host_blocked;
465
466 /*
467 * Default value for the blocking. If the queue is empty,
468 * host_blocked counts down in the request_fn until it restarts
469 * host operations as zero is reached.
470 *
471 * FIXME: This should probably be a value in the template
472 */
473#define SCSI_DEFAULT_HOST_BLOCKED 7
474
475 /*
476 * Pointer to the SCSI host sysfs attribute groups, NULL terminated.
477 */
478 const struct attribute_group **shost_groups;
479
480 /*
481 * Pointer to the SCSI device attribute groups for this host,
482 * NULL terminated.
483 */
484 const struct attribute_group **sdev_groups;
485
486 /*
487 * Vendor Identifier associated with the host
488 *
489 * Note: When specifying vendor_id, be sure to read the
490 * Vendor Type and ID formatting requirements specified in
491 * scsi_netlink.h
492 */
493 u64 vendor_id;
494
495 /* Delay for runtime autosuspend */
496 int rpm_autosuspend_delay;
497};
498
499/*
500 * Temporary #define for host lock push down. Can be removed when all
501 * drivers have been updated to take advantage of unlocked
502 * queuecommand.
503 *
504 */
505#define DEF_SCSI_QCMD(func_name) \
506 int func_name(struct Scsi_Host *shost, struct scsi_cmnd *cmd) \
507 { \
508 unsigned long irq_flags; \
509 int rc; \
510 spin_lock_irqsave(shost->host_lock, irq_flags); \
511 rc = func_name##_lck(cmd); \
512 spin_unlock_irqrestore(shost->host_lock, irq_flags); \
513 return rc; \
514 }
515
516
517/*
518 * shost state: If you alter this, you also need to alter scsi_sysfs.c
519 * (for the ascii descriptions) and the state model enforcer:
520 * scsi_host_set_state()
521 */
522enum scsi_host_state {
523 SHOST_CREATED = 1,
524 SHOST_RUNNING,
525 SHOST_CANCEL,
526 SHOST_DEL,
527 SHOST_RECOVERY,
528 SHOST_CANCEL_RECOVERY,
529 SHOST_DEL_RECOVERY,
530};
531
532struct Scsi_Host {
533 /*
534 * __devices is protected by the host_lock, but you should
535 * usually use scsi_device_lookup / shost_for_each_device
536 * to access it and don't care about locking yourself.
537 * In the rare case of being in irq context you can use
538 * their __ prefixed variants with the lock held. NEVER
539 * access this list directly from a driver.
540 */
541 struct list_head __devices;
542 struct list_head __targets;
543
544 struct list_head starved_list;
545
546 spinlock_t default_lock;
547 spinlock_t *host_lock;
548
549 struct mutex scan_mutex;/* serialize scanning activity */
550
551 struct list_head eh_abort_list;
552 struct list_head eh_cmd_q;
553 struct task_struct * ehandler; /* Error recovery thread. */
554 struct completion * eh_action; /* Wait for specific actions on the
555 host. */
556 wait_queue_head_t host_wait;
557 struct scsi_host_template *hostt;
558 struct scsi_transport_template *transportt;
559
560 struct kref tagset_refcnt;
561 struct completion tagset_freed;
562 /* Area to keep a shared tag map */
563 struct blk_mq_tag_set tag_set;
564
565 atomic_t host_blocked;
566
567 unsigned int host_failed; /* commands that failed.
568 protected by host_lock */
569 unsigned int host_eh_scheduled; /* EH scheduled without command */
570
571 unsigned int host_no; /* Used for IOCTL_GET_IDLUN, /proc/scsi et al. */
572
573 /* next two fields are used to bound the time spent in error handling */
574 int eh_deadline;
575 unsigned long last_reset;
576
577
578 /*
579 * These three parameters can be used to allow for wide scsi,
580 * and for host adapters that support multiple busses
581 * The last two should be set to 1 more than the actual max id
582 * or lun (e.g. 8 for SCSI parallel systems).
583 */
584 unsigned int max_channel;
585 unsigned int max_id;
586 u64 max_lun;
587
588 /*
589 * This is a unique identifier that must be assigned so that we
590 * have some way of identifying each detected host adapter properly
591 * and uniquely. For hosts that do not support more than one card
592 * in the system at one time, this does not need to be set. It is
593 * initialized to 0 in scsi_register.
594 */
595 unsigned int unique_id;
596
597 /*
598 * The maximum length of SCSI commands that this host can accept.
599 * Probably 12 for most host adapters, but could be 16 for others.
600 * or 260 if the driver supports variable length cdbs.
601 * For drivers that don't set this field, a value of 12 is
602 * assumed.
603 */
604 unsigned short max_cmd_len;
605
606 int this_id;
607 int can_queue;
608 short cmd_per_lun;
609 short unsigned int sg_tablesize;
610 short unsigned int sg_prot_tablesize;
611 unsigned int max_sectors;
612 unsigned int opt_sectors;
613 unsigned int max_segment_size;
614 unsigned long dma_boundary;
615 unsigned long virt_boundary_mask;
616 /*
617 * In scsi-mq mode, the number of hardware queues supported by the LLD.
618 *
619 * Note: it is assumed that each hardware queue has a queue depth of
620 * can_queue. In other words, the total queue depth per host
621 * is nr_hw_queues * can_queue. However, for when host_tagset is set,
622 * the total queue depth is can_queue.
623 */
624 unsigned nr_hw_queues;
625 unsigned nr_maps;
626 unsigned active_mode:2;
627
628 /*
629 * Host has requested that no further requests come through for the
630 * time being.
631 */
632 unsigned host_self_blocked:1;
633
634 /*
635 * Host uses correct SCSI ordering not PC ordering. The bit is
636 * set for the minority of drivers whose authors actually read
637 * the spec ;).
638 */
639 unsigned reverse_ordering:1;
640
641 /* Task mgmt function in progress */
642 unsigned tmf_in_progress:1;
643
644 /* Asynchronous scan in progress */
645 unsigned async_scan:1;
646
647 /* Don't resume host in EH */
648 unsigned eh_noresume:1;
649
650 /* The controller does not support WRITE SAME */
651 unsigned no_write_same:1;
652
653 /* True if the host uses host-wide tagspace */
654 unsigned host_tagset:1;
655
656 /* Host responded with short (<36 bytes) INQUIRY result */
657 unsigned short_inquiry:1;
658
659 /* The transport requires the LUN bits NOT to be stored in CDB[1] */
660 unsigned no_scsi2_lun_in_cdb:1;
661
662 /*
663 * Optional work queue to be utilized by the transport
664 */
665 char work_q_name[20];
666 struct workqueue_struct *work_q;
667
668 /*
669 * Task management function work queue
670 */
671 struct workqueue_struct *tmf_work_q;
672
673 /*
674 * Value host_blocked counts down from
675 */
676 unsigned int max_host_blocked;
677
678 /* Protection Information */
679 unsigned int prot_capabilities;
680 unsigned char prot_guard_type;
681
682 /* legacy crap */
683 unsigned long base;
684 unsigned long io_port;
685 unsigned char n_io_port;
686 unsigned char dma_channel;
687 unsigned int irq;
688
689
690 enum scsi_host_state shost_state;
691
692 /* ldm bits */
693 struct device shost_gendev, shost_dev;
694
695 /*
696 * Points to the transport data (if any) which is allocated
697 * separately
698 */
699 void *shost_data;
700
701 /*
702 * Points to the physical bus device we'd use to do DMA
703 * Needed just in case we have virtual hosts.
704 */
705 struct device *dma_dev;
706
707 /*
708 * We should ensure that this is aligned, both for better performance
709 * and also because some compilers (m68k) don't automatically force
710 * alignment to a long boundary.
711 */
712 unsigned long hostdata[] /* Used for storage of host specific stuff */
713 __attribute__ ((aligned (sizeof(unsigned long))));
714};
715
716#define class_to_shost(d) \
717 container_of(d, struct Scsi_Host, shost_dev)
718
719#define shost_printk(prefix, shost, fmt, a...) \
720 dev_printk(prefix, &(shost)->shost_gendev, fmt, ##a)
721
722static inline void *shost_priv(struct Scsi_Host *shost)
723{
724 return (void *)shost->hostdata;
725}
726
727int scsi_is_host_device(const struct device *);
728
729static inline struct Scsi_Host *dev_to_shost(struct device *dev)
730{
731 while (!scsi_is_host_device(dev)) {
732 if (!dev->parent)
733 return NULL;
734 dev = dev->parent;
735 }
736 return container_of(dev, struct Scsi_Host, shost_gendev);
737}
738
739static inline int scsi_host_in_recovery(struct Scsi_Host *shost)
740{
741 return shost->shost_state == SHOST_RECOVERY ||
742 shost->shost_state == SHOST_CANCEL_RECOVERY ||
743 shost->shost_state == SHOST_DEL_RECOVERY ||
744 shost->tmf_in_progress;
745}
746
747extern int scsi_queue_work(struct Scsi_Host *, struct work_struct *);
748extern void scsi_flush_work(struct Scsi_Host *);
749
750extern struct Scsi_Host *scsi_host_alloc(struct scsi_host_template *, int);
751extern int __must_check scsi_add_host_with_dma(struct Scsi_Host *,
752 struct device *,
753 struct device *);
754#if defined(CONFIG_SCSI_PROC_FS)
755struct proc_dir_entry *
756scsi_template_proc_dir(const struct scsi_host_template *sht);
757#else
758#define scsi_template_proc_dir(sht) NULL
759#endif
760extern void scsi_scan_host(struct Scsi_Host *);
761extern void scsi_rescan_device(struct device *);
762extern void scsi_remove_host(struct Scsi_Host *);
763extern struct Scsi_Host *scsi_host_get(struct Scsi_Host *);
764extern int scsi_host_busy(struct Scsi_Host *shost);
765extern void scsi_host_put(struct Scsi_Host *t);
766extern struct Scsi_Host *scsi_host_lookup(unsigned short);
767extern const char *scsi_host_state_name(enum scsi_host_state);
768extern void scsi_host_complete_all_commands(struct Scsi_Host *shost,
769 enum scsi_host_status status);
770
771static inline int __must_check scsi_add_host(struct Scsi_Host *host,
772 struct device *dev)
773{
774 return scsi_add_host_with_dma(host, dev, dev);
775}
776
777static inline struct device *scsi_get_device(struct Scsi_Host *shost)
778{
779 return shost->shost_gendev.parent;
780}
781
782/**
783 * scsi_host_scan_allowed - Is scanning of this host allowed
784 * @shost: Pointer to Scsi_Host.
785 **/
786static inline int scsi_host_scan_allowed(struct Scsi_Host *shost)
787{
788 return shost->shost_state == SHOST_RUNNING ||
789 shost->shost_state == SHOST_RECOVERY;
790}
791
792extern void scsi_unblock_requests(struct Scsi_Host *);
793extern void scsi_block_requests(struct Scsi_Host *);
794extern int scsi_host_block(struct Scsi_Host *shost);
795extern int scsi_host_unblock(struct Scsi_Host *shost, int new_state);
796
797void scsi_host_busy_iter(struct Scsi_Host *,
798 bool (*fn)(struct scsi_cmnd *, void *), void *priv);
799
800struct class_container;
801
802/*
803 * DIF defines the exchange of protection information between
804 * initiator and SBC block device.
805 *
806 * DIX defines the exchange of protection information between OS and
807 * initiator.
808 */
809enum scsi_host_prot_capabilities {
810 SHOST_DIF_TYPE1_PROTECTION = 1 << 0, /* T10 DIF Type 1 */
811 SHOST_DIF_TYPE2_PROTECTION = 1 << 1, /* T10 DIF Type 2 */
812 SHOST_DIF_TYPE3_PROTECTION = 1 << 2, /* T10 DIF Type 3 */
813
814 SHOST_DIX_TYPE0_PROTECTION = 1 << 3, /* DIX between OS and HBA only */
815 SHOST_DIX_TYPE1_PROTECTION = 1 << 4, /* DIX with DIF Type 1 */
816 SHOST_DIX_TYPE2_PROTECTION = 1 << 5, /* DIX with DIF Type 2 */
817 SHOST_DIX_TYPE3_PROTECTION = 1 << 6, /* DIX with DIF Type 3 */
818};
819
820/*
821 * SCSI hosts which support the Data Integrity Extensions must
822 * indicate their capabilities by setting the prot_capabilities using
823 * this call.
824 */
825static inline void scsi_host_set_prot(struct Scsi_Host *shost, unsigned int mask)
826{
827 shost->prot_capabilities = mask;
828}
829
830static inline unsigned int scsi_host_get_prot(struct Scsi_Host *shost)
831{
832 return shost->prot_capabilities;
833}
834
835static inline int scsi_host_prot_dma(struct Scsi_Host *shost)
836{
837 return shost->prot_capabilities >= SHOST_DIX_TYPE0_PROTECTION;
838}
839
840static inline unsigned int scsi_host_dif_capable(struct Scsi_Host *shost, unsigned int target_type)
841{
842 static unsigned char cap[] = { 0,
843 SHOST_DIF_TYPE1_PROTECTION,
844 SHOST_DIF_TYPE2_PROTECTION,
845 SHOST_DIF_TYPE3_PROTECTION };
846
847 if (target_type >= ARRAY_SIZE(cap))
848 return 0;
849
850 return shost->prot_capabilities & cap[target_type] ? target_type : 0;
851}
852
853static inline unsigned int scsi_host_dix_capable(struct Scsi_Host *shost, unsigned int target_type)
854{
855#if defined(CONFIG_BLK_DEV_INTEGRITY)
856 static unsigned char cap[] = { SHOST_DIX_TYPE0_PROTECTION,
857 SHOST_DIX_TYPE1_PROTECTION,
858 SHOST_DIX_TYPE2_PROTECTION,
859 SHOST_DIX_TYPE3_PROTECTION };
860
861 if (target_type >= ARRAY_SIZE(cap))
862 return 0;
863
864 return shost->prot_capabilities & cap[target_type];
865#endif
866 return 0;
867}
868
869/*
870 * All DIX-capable initiators must support the T10-mandated CRC
871 * checksum. Controllers can optionally implement the IP checksum
872 * scheme which has much lower impact on system performance. Note
873 * that the main rationale for the checksum is to match integrity
874 * metadata with data. Detecting bit errors are a job for ECC memory
875 * and buses.
876 */
877
878enum scsi_host_guard_type {
879 SHOST_DIX_GUARD_CRC = 1 << 0,
880 SHOST_DIX_GUARD_IP = 1 << 1,
881};
882
883static inline void scsi_host_set_guard(struct Scsi_Host *shost, unsigned char type)
884{
885 shost->prot_guard_type = type;
886}
887
888static inline unsigned char scsi_host_get_guard(struct Scsi_Host *shost)
889{
890 return shost->prot_guard_type;
891}
892
893extern int scsi_host_set_state(struct Scsi_Host *, enum scsi_host_state);
894
895#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 SG_CHUNK_SIZE
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 functions lets the driver expose the queue mapping
282 * to the block layer.
283 *
284 * Status: OPTIONAL
285 */
286 int (* map_queues)(struct Scsi_Host *shost);
287
288 /*
289 * This function determines the BIOS parameters for a given
290 * harddisk. These tend to be numbers that are made up by
291 * the host adapter. Parameters:
292 * size, device, list (heads, sectors, cylinders)
293 *
294 * Status: OPTIONAL
295 */
296 int (* bios_param)(struct scsi_device *, struct block_device *,
297 sector_t, int []);
298
299 /*
300 * This function is called when one or more partitions on the
301 * device reach beyond the end of the device.
302 *
303 * Status: OPTIONAL
304 */
305 void (*unlock_native_capacity)(struct scsi_device *);
306
307 /*
308 * Can be used to export driver statistics and other infos to the
309 * world outside the kernel ie. userspace and it also provides an
310 * interface to feed the driver with information.
311 *
312 * Status: OBSOLETE
313 */
314 int (*show_info)(struct seq_file *, struct Scsi_Host *);
315 int (*write_info)(struct Scsi_Host *, char *, int);
316
317 /*
318 * This is an optional routine that allows the transport to become
319 * involved when a scsi io timer fires. The return value tells the
320 * timer routine how to finish the io timeout handling:
321 * EH_HANDLED: I fixed the error, please complete the command
322 * EH_RESET_TIMER: I need more time, reset the timer and
323 * begin counting again
324 * EH_NOT_HANDLED Begin normal error recovery
325 *
326 * Status: OPTIONAL
327 */
328 enum blk_eh_timer_return (*eh_timed_out)(struct scsi_cmnd *);
329
330 /* This is an optional routine that allows transport to initiate
331 * LLD adapter or firmware reset using sysfs attribute.
332 *
333 * Return values: 0 on success, -ve value on failure.
334 *
335 * Status: OPTIONAL
336 */
337
338 int (*host_reset)(struct Scsi_Host *shost, int reset_type);
339#define SCSI_ADAPTER_RESET 1
340#define SCSI_FIRMWARE_RESET 2
341
342
343 /*
344 * Name of proc directory
345 */
346 const char *proc_name;
347
348 /*
349 * Used to store the procfs directory if a driver implements the
350 * show_info method.
351 */
352 struct proc_dir_entry *proc_dir;
353
354 /*
355 * This determines if we will use a non-interrupt driven
356 * or an interrupt driven scheme. It is set to the maximum number
357 * of simultaneous commands a given host adapter will accept.
358 */
359 int can_queue;
360
361 /*
362 * In many instances, especially where disconnect / reconnect are
363 * supported, our host also has an ID on the SCSI bus. If this is
364 * the case, then it must be reserved. Please set this_id to -1 if
365 * your setup is in single initiator mode, and the host lacks an
366 * ID.
367 */
368 int this_id;
369
370 /*
371 * This determines the degree to which the host adapter is capable
372 * of scatter-gather.
373 */
374 unsigned short sg_tablesize;
375 unsigned short sg_prot_tablesize;
376
377 /*
378 * Set this if the host adapter has limitations beside segment count.
379 */
380 unsigned int max_sectors;
381
382 /*
383 * DMA scatter gather segment boundary limit. A segment crossing this
384 * boundary will be split in two.
385 */
386 unsigned long dma_boundary;
387
388 /*
389 * This specifies "machine infinity" for host templates which don't
390 * limit the transfer size. Note this limit represents an absolute
391 * maximum, and may be over the transfer limits allowed for
392 * individual devices (e.g. 256 for SCSI-1).
393 */
394#define SCSI_DEFAULT_MAX_SECTORS 1024
395
396 /*
397 * True if this host adapter can make good use of linked commands.
398 * This will allow more than one command to be queued to a given
399 * unit on a given host. Set this to the maximum number of command
400 * blocks to be provided for each device. Set this to 1 for one
401 * command block per lun, 2 for two, etc. Do not set this to 0.
402 * You should make sure that the host adapter will do the right thing
403 * before you try setting this above 1.
404 */
405 short cmd_per_lun;
406
407 /*
408 * present contains counter indicating how many boards of this
409 * type were found when we did the scan.
410 */
411 unsigned char present;
412
413 /* If use block layer to manage tags, this is tag allocation policy */
414 int tag_alloc_policy;
415
416 /*
417 * Track QUEUE_FULL events and reduce queue depth on demand.
418 */
419 unsigned track_queue_depth:1;
420
421 /*
422 * This specifies the mode that a LLD supports.
423 */
424 unsigned supported_mode:2;
425
426 /*
427 * True if this host adapter uses unchecked DMA onto an ISA bus.
428 */
429 unsigned unchecked_isa_dma:1;
430
431 /*
432 * True if this host adapter can make good use of clustering.
433 * I originally thought that if the tablesize was large that it
434 * was a waste of CPU cycles to prepare a cluster list, but
435 * it works out that the Buslogic is faster if you use a smaller
436 * number of segments (i.e. use clustering). I guess it is
437 * inefficient.
438 */
439 unsigned use_clustering:1;
440
441 /*
442 * True for emulated SCSI host adapters (e.g. ATAPI).
443 */
444 unsigned emulated:1;
445
446 /*
447 * True if the low-level driver performs its own reset-settle delays.
448 */
449 unsigned skip_settle_delay:1;
450
451 /* True if the controller does not support WRITE SAME */
452 unsigned no_write_same:1;
453
454 /*
455 * True if asynchronous aborts are not supported
456 */
457 unsigned no_async_abort:1;
458
459 /*
460 * Countdown for host blocking with no commands outstanding.
461 */
462 unsigned int max_host_blocked;
463
464 /*
465 * Default value for the blocking. If the queue is empty,
466 * host_blocked counts down in the request_fn until it restarts
467 * host operations as zero is reached.
468 *
469 * FIXME: This should probably be a value in the template
470 */
471#define SCSI_DEFAULT_HOST_BLOCKED 7
472
473 /*
474 * Pointer to the sysfs class properties for this host, NULL terminated.
475 */
476 struct device_attribute **shost_attrs;
477
478 /*
479 * Pointer to the SCSI device properties for this host, NULL terminated.
480 */
481 struct device_attribute **sdev_attrs;
482
483 /*
484 * List of hosts per template.
485 *
486 * This is only for use by scsi_module.c for legacy templates.
487 * For these access to it is synchronized implicitly by
488 * module_init/module_exit.
489 */
490 struct list_head legacy_hosts;
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 /*
502 * Additional per-command data allocated for the driver.
503 */
504 unsigned int cmd_size;
505 struct scsi_host_cmd_pool *cmd_pool;
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 scsi_cmd_get_serial(shost, cmd); \
521 rc = func_name##_lck (cmd, cmd->scsi_done); \
522 spin_unlock_irqrestore(shost->host_lock, irq_flags); \
523 return rc; \
524 }
525
526
527/*
528 * shost state: If you alter this, you also need to alter scsi_sysfs.c
529 * (for the ascii descriptions) and the state model enforcer:
530 * scsi_host_set_state()
531 */
532enum scsi_host_state {
533 SHOST_CREATED = 1,
534 SHOST_RUNNING,
535 SHOST_CANCEL,
536 SHOST_DEL,
537 SHOST_RECOVERY,
538 SHOST_CANCEL_RECOVERY,
539 SHOST_DEL_RECOVERY,
540};
541
542struct Scsi_Host {
543 /*
544 * __devices is protected by the host_lock, but you should
545 * usually use scsi_device_lookup / shost_for_each_device
546 * to access it and don't care about locking yourself.
547 * In the rare case of being in irq context you can use
548 * their __ prefixed variants with the lock held. NEVER
549 * access this list directly from a driver.
550 */
551 struct list_head __devices;
552 struct list_head __targets;
553
554 struct scsi_host_cmd_pool *cmd_pool;
555 spinlock_t free_list_lock;
556 struct list_head free_list; /* backup store of cmd structs */
557 struct list_head starved_list;
558
559 spinlock_t default_lock;
560 spinlock_t *host_lock;
561
562 struct mutex scan_mutex;/* serialize scanning activity */
563
564 struct list_head eh_cmd_q;
565 struct task_struct * ehandler; /* Error recovery thread. */
566 struct completion * eh_action; /* Wait for specific actions on the
567 host. */
568 wait_queue_head_t host_wait;
569 struct scsi_host_template *hostt;
570 struct scsi_transport_template *transportt;
571
572 /*
573 * Area to keep a shared tag map (if needed, will be
574 * NULL if not).
575 */
576 union {
577 struct blk_queue_tag *bqt;
578 struct blk_mq_tag_set tag_set;
579 };
580
581 atomic_t host_busy; /* commands actually active on low-level */
582 atomic_t host_blocked;
583
584 unsigned int host_failed; /* commands that failed.
585 protected by host_lock */
586 unsigned int host_eh_scheduled; /* EH scheduled without command */
587
588 unsigned int host_no; /* Used for IOCTL_GET_IDLUN, /proc/scsi et al. */
589
590 /* next two fields are used to bound the time spent in error handling */
591 int eh_deadline;
592 unsigned long last_reset;
593
594
595 /*
596 * These three parameters can be used to allow for wide scsi,
597 * and for host adapters that support multiple busses
598 * The last two should be set to 1 more than the actual max id
599 * or lun (e.g. 8 for SCSI parallel systems).
600 */
601 unsigned int max_channel;
602 unsigned int max_id;
603 u64 max_lun;
604
605 /*
606 * This is a unique identifier that must be assigned so that we
607 * have some way of identifying each detected host adapter properly
608 * and uniquely. For hosts that do not support more than one card
609 * in the system at one time, this does not need to be set. It is
610 * initialized to 0 in scsi_register.
611 */
612 unsigned int unique_id;
613
614 /*
615 * The maximum length of SCSI commands that this host can accept.
616 * Probably 12 for most host adapters, but could be 16 for others.
617 * or 260 if the driver supports variable length cdbs.
618 * For drivers that don't set this field, a value of 12 is
619 * assumed.
620 */
621 unsigned short max_cmd_len;
622
623 int this_id;
624 int can_queue;
625 short cmd_per_lun;
626 short unsigned int sg_tablesize;
627 short unsigned int sg_prot_tablesize;
628 unsigned int max_sectors;
629 unsigned long dma_boundary;
630 /*
631 * In scsi-mq mode, the number of hardware queues supported by the LLD.
632 *
633 * Note: it is assumed that each hardware queue has a queue depth of
634 * can_queue. In other words, the total queue depth per host
635 * is nr_hw_queues * can_queue.
636 */
637 unsigned nr_hw_queues;
638 /*
639 * Used to assign serial numbers to the cmds.
640 * Protected by the host lock.
641 */
642 unsigned long cmd_serial_number;
643
644 unsigned active_mode:2;
645 unsigned unchecked_isa_dma:1;
646 unsigned use_clustering:1;
647
648 /*
649 * Host has requested that no further requests come through for the
650 * time being.
651 */
652 unsigned host_self_blocked:1;
653
654 /*
655 * Host uses correct SCSI ordering not PC ordering. The bit is
656 * set for the minority of drivers whose authors actually read
657 * the spec ;).
658 */
659 unsigned reverse_ordering:1;
660
661 /* Task mgmt function in progress */
662 unsigned tmf_in_progress:1;
663
664 /* Asynchronous scan in progress */
665 unsigned async_scan:1;
666
667 /* Don't resume host in EH */
668 unsigned eh_noresume:1;
669
670 /* The controller does not support WRITE SAME */
671 unsigned no_write_same:1;
672
673 unsigned use_blk_mq:1;
674 unsigned use_cmd_list:1;
675
676 /* Host responded with short (<36 bytes) INQUIRY result */
677 unsigned short_inquiry:1;
678
679 /*
680 * Optional work queue to be utilized by the transport
681 */
682 char work_q_name[20];
683 struct workqueue_struct *work_q;
684
685 /*
686 * Task management function work queue
687 */
688 struct workqueue_struct *tmf_work_q;
689
690 /* The transport requires the LUN bits NOT to be stored in CDB[1] */
691 unsigned no_scsi2_lun_in_cdb:1;
692
693 /*
694 * Value host_blocked counts down from
695 */
696 unsigned int max_host_blocked;
697
698 /* Protection Information */
699 unsigned int prot_capabilities;
700 unsigned char prot_guard_type;
701
702 /*
703 * q used for scsi_tgt msgs, async events or any other requests that
704 * need to be processed in userspace
705 */
706 struct request_queue *uspace_req_q;
707
708 /* legacy crap */
709 unsigned long base;
710 unsigned long io_port;
711 unsigned char n_io_port;
712 unsigned char dma_channel;
713 unsigned int irq;
714
715
716 enum scsi_host_state shost_state;
717
718 /* ldm bits */
719 struct device shost_gendev, shost_dev;
720
721 /*
722 * List of hosts per template.
723 *
724 * This is only for use by scsi_module.c for legacy templates.
725 * For these access to it is synchronized implicitly by
726 * module_init/module_exit.
727 */
728 struct list_head sht_legacy_list;
729
730 /*
731 * Points to the transport data (if any) which is allocated
732 * separately
733 */
734 void *shost_data;
735
736 /*
737 * Points to the physical bus device we'd use to do DMA
738 * Needed just in case we have virtual hosts.
739 */
740 struct device *dma_dev;
741
742 /*
743 * We should ensure that this is aligned, both for better performance
744 * and also because some compilers (m68k) don't automatically force
745 * alignment to a long boundary.
746 */
747 unsigned long hostdata[0] /* Used for storage of host specific stuff */
748 __attribute__ ((aligned (sizeof(unsigned long))));
749};
750
751#define class_to_shost(d) \
752 container_of(d, struct Scsi_Host, shost_dev)
753
754#define shost_printk(prefix, shost, fmt, a...) \
755 dev_printk(prefix, &(shost)->shost_gendev, fmt, ##a)
756
757static inline void *shost_priv(struct Scsi_Host *shost)
758{
759 return (void *)shost->hostdata;
760}
761
762int scsi_is_host_device(const struct device *);
763
764static inline struct Scsi_Host *dev_to_shost(struct device *dev)
765{
766 while (!scsi_is_host_device(dev)) {
767 if (!dev->parent)
768 return NULL;
769 dev = dev->parent;
770 }
771 return container_of(dev, struct Scsi_Host, shost_gendev);
772}
773
774static inline int scsi_host_in_recovery(struct Scsi_Host *shost)
775{
776 return shost->shost_state == SHOST_RECOVERY ||
777 shost->shost_state == SHOST_CANCEL_RECOVERY ||
778 shost->shost_state == SHOST_DEL_RECOVERY ||
779 shost->tmf_in_progress;
780}
781
782static inline bool shost_use_blk_mq(struct Scsi_Host *shost)
783{
784 return shost->use_blk_mq;
785}
786
787extern int scsi_queue_work(struct Scsi_Host *, struct work_struct *);
788extern void scsi_flush_work(struct Scsi_Host *);
789
790extern struct Scsi_Host *scsi_host_alloc(struct scsi_host_template *, int);
791extern int __must_check scsi_add_host_with_dma(struct Scsi_Host *,
792 struct device *,
793 struct device *);
794extern void scsi_scan_host(struct Scsi_Host *);
795extern void scsi_rescan_device(struct device *);
796extern void scsi_remove_host(struct Scsi_Host *);
797extern struct Scsi_Host *scsi_host_get(struct Scsi_Host *);
798extern void scsi_host_put(struct Scsi_Host *t);
799extern struct Scsi_Host *scsi_host_lookup(unsigned short);
800extern const char *scsi_host_state_name(enum scsi_host_state);
801extern void scsi_cmd_get_serial(struct Scsi_Host *, struct scsi_cmnd *);
802
803static inline int __must_check scsi_add_host(struct Scsi_Host *host,
804 struct device *dev)
805{
806 return scsi_add_host_with_dma(host, dev, dev);
807}
808
809static inline struct device *scsi_get_device(struct Scsi_Host *shost)
810{
811 return shost->shost_gendev.parent;
812}
813
814/**
815 * scsi_host_scan_allowed - Is scanning of this host allowed
816 * @shost: Pointer to Scsi_Host.
817 **/
818static inline int scsi_host_scan_allowed(struct Scsi_Host *shost)
819{
820 return shost->shost_state == SHOST_RUNNING ||
821 shost->shost_state == SHOST_RECOVERY;
822}
823
824extern void scsi_unblock_requests(struct Scsi_Host *);
825extern void scsi_block_requests(struct Scsi_Host *);
826
827struct class_container;
828
829extern struct request_queue *__scsi_alloc_queue(struct Scsi_Host *shost,
830 void (*) (struct request_queue *));
831/*
832 * These two functions are used to allocate and free a pseudo device
833 * which will connect to the host adapter itself rather than any
834 * physical device. You must deallocate when you are done with the
835 * thing. This physical pseudo-device isn't real and won't be available
836 * from any high-level drivers.
837 */
838extern void scsi_free_host_dev(struct scsi_device *);
839extern struct scsi_device *scsi_get_host_dev(struct Scsi_Host *);
840
841/*
842 * DIF defines the exchange of protection information between
843 * initiator and SBC block device.
844 *
845 * DIX defines the exchange of protection information between OS and
846 * initiator.
847 */
848enum scsi_host_prot_capabilities {
849 SHOST_DIF_TYPE1_PROTECTION = 1 << 0, /* T10 DIF Type 1 */
850 SHOST_DIF_TYPE2_PROTECTION = 1 << 1, /* T10 DIF Type 2 */
851 SHOST_DIF_TYPE3_PROTECTION = 1 << 2, /* T10 DIF Type 3 */
852
853 SHOST_DIX_TYPE0_PROTECTION = 1 << 3, /* DIX between OS and HBA only */
854 SHOST_DIX_TYPE1_PROTECTION = 1 << 4, /* DIX with DIF Type 1 */
855 SHOST_DIX_TYPE2_PROTECTION = 1 << 5, /* DIX with DIF Type 2 */
856 SHOST_DIX_TYPE3_PROTECTION = 1 << 6, /* DIX with DIF Type 3 */
857};
858
859/*
860 * SCSI hosts which support the Data Integrity Extensions must
861 * indicate their capabilities by setting the prot_capabilities using
862 * this call.
863 */
864static inline void scsi_host_set_prot(struct Scsi_Host *shost, unsigned int mask)
865{
866 shost->prot_capabilities = mask;
867}
868
869static inline unsigned int scsi_host_get_prot(struct Scsi_Host *shost)
870{
871 return shost->prot_capabilities;
872}
873
874static inline int scsi_host_prot_dma(struct Scsi_Host *shost)
875{
876 return shost->prot_capabilities >= SHOST_DIX_TYPE0_PROTECTION;
877}
878
879static inline unsigned int scsi_host_dif_capable(struct Scsi_Host *shost, unsigned int target_type)
880{
881 static unsigned char cap[] = { 0,
882 SHOST_DIF_TYPE1_PROTECTION,
883 SHOST_DIF_TYPE2_PROTECTION,
884 SHOST_DIF_TYPE3_PROTECTION };
885
886 if (target_type >= ARRAY_SIZE(cap))
887 return 0;
888
889 return shost->prot_capabilities & cap[target_type] ? target_type : 0;
890}
891
892static inline unsigned int scsi_host_dix_capable(struct Scsi_Host *shost, unsigned int target_type)
893{
894#if defined(CONFIG_BLK_DEV_INTEGRITY)
895 static unsigned char cap[] = { SHOST_DIX_TYPE0_PROTECTION,
896 SHOST_DIX_TYPE1_PROTECTION,
897 SHOST_DIX_TYPE2_PROTECTION,
898 SHOST_DIX_TYPE3_PROTECTION };
899
900 if (target_type >= ARRAY_SIZE(cap))
901 return 0;
902
903 return shost->prot_capabilities & cap[target_type];
904#endif
905 return 0;
906}
907
908/*
909 * All DIX-capable initiators must support the T10-mandated CRC
910 * checksum. Controllers can optionally implement the IP checksum
911 * scheme which has much lower impact on system performance. Note
912 * that the main rationale for the checksum is to match integrity
913 * metadata with data. Detecting bit errors are a job for ECC memory
914 * and buses.
915 */
916
917enum scsi_host_guard_type {
918 SHOST_DIX_GUARD_CRC = 1 << 0,
919 SHOST_DIX_GUARD_IP = 1 << 1,
920};
921
922static inline void scsi_host_set_guard(struct Scsi_Host *shost, unsigned char type)
923{
924 shost->prot_guard_type = type;
925}
926
927static inline unsigned char scsi_host_get_guard(struct Scsi_Host *shost)
928{
929 return shost->prot_guard_type;
930}
931
932/* legacy interfaces */
933extern struct Scsi_Host *scsi_register(struct scsi_host_template *, int);
934extern void scsi_unregister(struct Scsi_Host *);
935extern int scsi_host_set_state(struct Scsi_Host *, enum scsi_host_state);
936
937#endif /* _SCSI_SCSI_HOST_H */