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 
14 struct block_device;
15 struct completion;
16 struct module;
17 struct scsi_cmnd;
18 struct scsi_device;
19 struct scsi_target;
20 struct Scsi_Host;
21 struct 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 struct scsi_host_template {
31 	/*
32 	 * Put fields referenced in IO submission path together in
33 	 * same cacheline
34 	 */
35 
36 	/*
37 	 * Additional per-command data allocated for the driver.
38 	 */
39 	unsigned int cmd_size;
40 
41 	/*
42 	 * The queuecommand function is used to queue up a scsi
43 	 * command block to the LLDD.  When the driver finished
44 	 * processing the command the done callback is invoked.
45 	 *
46 	 * If queuecommand returns 0, then the driver has accepted the
47 	 * command.  It must also push it to the HBA if the scsi_cmnd
48 	 * flag SCMD_LAST is set, or if the driver does not implement
49 	 * commit_rqs.  The done() function must be called on the command
50 	 * when the driver has finished with it. (you may call done on the
51 	 * command before queuecommand returns, but in this case you
52 	 * *must* return 0 from queuecommand).
53 	 *
54 	 * Queuecommand may also reject the command, in which case it may
55 	 * not touch the command and must not call done() for it.
56 	 *
57 	 * There are two possible rejection returns:
58 	 *
59 	 *   SCSI_MLQUEUE_DEVICE_BUSY: Block this device temporarily, but
60 	 *   allow commands to other devices serviced by this host.
61 	 *
62 	 *   SCSI_MLQUEUE_HOST_BUSY: Block all devices served by this
63 	 *   host temporarily.
64 	 *
65          * For compatibility, any other non-zero return is treated the
66          * same as SCSI_MLQUEUE_HOST_BUSY.
67 	 *
68 	 * NOTE: "temporarily" means either until the next command for#
69 	 * this device/host completes, or a period of time determined by
70 	 * I/O pressure in the system if there are no other outstanding
71 	 * commands.
72 	 *
73 	 * STATUS: REQUIRED
74 	 */
75 	int (* queuecommand)(struct Scsi_Host *, struct scsi_cmnd *);
76 
77 	/*
78 	 * The commit_rqs function is used to trigger a hardware
79 	 * doorbell after some requests have been queued with
80 	 * queuecommand, when an error is encountered before sending
81 	 * the request with SCMD_LAST set.
82 	 *
83 	 * STATUS: OPTIONAL
84 	 */
85 	void (*commit_rqs)(struct Scsi_Host *, u16);
86 
87 	struct module *module;
88 	const char *name;
89 
90 	/*
91 	 * The info function will return whatever useful information the
92 	 * developer sees fit.  If not provided, then the name field will
93 	 * be used instead.
94 	 *
95 	 * Status: OPTIONAL
96 	 */
97 	const char *(*info)(struct Scsi_Host *);
98 
99 	/*
100 	 * Ioctl interface
101 	 *
102 	 * Status: OPTIONAL
103 	 */
104 	int (*ioctl)(struct scsi_device *dev, unsigned int cmd,
105 		     void __user *arg);
106 
107 
108 #ifdef CONFIG_COMPAT
109 	/*
110 	 * Compat handler. Handle 32bit ABI.
111 	 * When unknown ioctl is passed return -ENOIOCTLCMD.
112 	 *
113 	 * Status: OPTIONAL
114 	 */
115 	int (*compat_ioctl)(struct scsi_device *dev, unsigned int cmd,
116 			    void __user *arg);
117 #endif
118 
119 	int (*init_cmd_priv)(struct Scsi_Host *shost, struct scsi_cmnd *cmd);
120 	int (*exit_cmd_priv)(struct Scsi_Host *shost, struct scsi_cmnd *cmd);
121 
122 	/*
123 	 * This is an error handling strategy routine.  You don't need to
124 	 * define one of these if you don't want to - there is a default
125 	 * routine that is present that should work in most cases.  For those
126 	 * driver authors that have the inclination and ability to write their
127 	 * own strategy routine, this is where it is specified.  Note - the
128 	 * strategy routine is *ALWAYS* run in the context of the kernel eh
129 	 * thread.  Thus you are guaranteed to *NOT* be in an interrupt
130 	 * handler when you execute this, and you are also guaranteed to
131 	 * *NOT* have any other commands being queued while you are in the
132 	 * strategy routine. When you return from this function, operations
133 	 * return to normal.
134 	 *
135 	 * See scsi_error.c scsi_unjam_host for additional comments about
136 	 * what this function should and should not be attempting to do.
137 	 *
138 	 * Status: REQUIRED	(at least one of them)
139 	 */
140 	int (* eh_abort_handler)(struct scsi_cmnd *);
141 	int (* eh_device_reset_handler)(struct scsi_cmnd *);
142 	int (* eh_target_reset_handler)(struct scsi_cmnd *);
143 	int (* eh_bus_reset_handler)(struct scsi_cmnd *);
144 	int (* eh_host_reset_handler)(struct scsi_cmnd *);
145 
146 	/*
147 	 * Before the mid layer attempts to scan for a new device where none
148 	 * currently exists, it will call this entry in your driver.  Should
149 	 * your driver need to allocate any structs or perform any other init
150 	 * items in order to send commands to a currently unused target/lun
151 	 * combo, then this is where you can perform those allocations.  This
152 	 * is specifically so that drivers won't have to perform any kind of
153 	 * "is this a new device" checks in their queuecommand routine,
154 	 * thereby making the hot path a bit quicker.
155 	 *
156 	 * Return values: 0 on success, non-0 on failure
157 	 *
158 	 * Deallocation:  If we didn't find any devices at this ID, you will
159 	 * get an immediate call to slave_destroy().  If we find something
160 	 * here then you will get a call to slave_configure(), then the
161 	 * device will be used for however long it is kept around, then when
162 	 * the device is removed from the system (or * possibly at reboot
163 	 * time), you will then get a call to slave_destroy().  This is
164 	 * assuming you implement slave_configure and slave_destroy.
165 	 * However, if you allocate memory and hang it off the device struct,
166 	 * then you must implement the slave_destroy() routine at a minimum
167 	 * in order to avoid leaking memory
168 	 * each time a device is tore down.
169 	 *
170 	 * Status: OPTIONAL
171 	 */
172 	int (* slave_alloc)(struct scsi_device *);
173 
174 	/*
175 	 * Once the device has responded to an INQUIRY and we know the
176 	 * device is online, we call into the low level driver with the
177 	 * struct scsi_device *.  If the low level device driver implements
178 	 * this function, it *must* perform the task of setting the queue
179 	 * depth on the device.  All other tasks are optional and depend
180 	 * on what the driver supports and various implementation details.
181 	 *
182 	 * Things currently recommended to be handled at this time include:
183 	 *
184 	 * 1.  Setting the device queue depth.  Proper setting of this is
185 	 *     described in the comments for scsi_change_queue_depth.
186 	 * 2.  Determining if the device supports the various synchronous
187 	 *     negotiation protocols.  The device struct will already have
188 	 *     responded to INQUIRY and the results of the standard items
189 	 *     will have been shoved into the various device flag bits, eg.
190 	 *     device->sdtr will be true if the device supports SDTR messages.
191 	 * 3.  Allocating command structs that the device will need.
192 	 * 4.  Setting the default timeout on this device (if needed).
193 	 * 5.  Anything else the low level driver might want to do on a device
194 	 *     specific setup basis...
195 	 * 6.  Return 0 on success, non-0 on error.  The device will be marked
196 	 *     as offline on error so that no access will occur.  If you return
197 	 *     non-0, your slave_destroy routine will never get called for this
198 	 *     device, so don't leave any loose memory hanging around, clean
199 	 *     up after yourself before returning non-0
200 	 *
201 	 * Status: OPTIONAL
202 	 */
203 	int (* slave_configure)(struct scsi_device *);
204 
205 	/*
206 	 * Immediately prior to deallocating the device and after all activity
207 	 * has ceased the mid layer calls this point so that the low level
208 	 * driver may completely detach itself from the scsi device and vice
209 	 * versa.  The low level driver is responsible for freeing any memory
210 	 * it allocated in the slave_alloc or slave_configure calls.
211 	 *
212 	 * Status: OPTIONAL
213 	 */
214 	void (* slave_destroy)(struct scsi_device *);
215 
216 	/*
217 	 * Before the mid layer attempts to scan for a new device attached
218 	 * to a target where no target currently exists, it will call this
219 	 * entry in your driver.  Should your driver need to allocate any
220 	 * structs or perform any other init items in order to send commands
221 	 * to a currently unused target, then this is where you can perform
222 	 * those allocations.
223 	 *
224 	 * Return values: 0 on success, non-0 on failure
225 	 *
226 	 * Status: OPTIONAL
227 	 */
228 	int (* target_alloc)(struct scsi_target *);
229 
230 	/*
231 	 * Immediately prior to deallocating the target structure, and
232 	 * after all activity to attached scsi devices has ceased, the
233 	 * midlayer calls this point so that the driver may deallocate
234 	 * and terminate any references to the target.
235 	 *
236 	 * Status: OPTIONAL
237 	 */
238 	void (* target_destroy)(struct scsi_target *);
239 
240 	/*
241 	 * If a host has the ability to discover targets on its own instead
242 	 * of scanning the entire bus, it can fill in this function and
243 	 * call scsi_scan_host().  This function will be called periodically
244 	 * until it returns 1 with the scsi_host and the elapsed time of
245 	 * the scan in jiffies.
246 	 *
247 	 * Status: OPTIONAL
248 	 */
249 	int (* scan_finished)(struct Scsi_Host *, unsigned long);
250 
251 	/*
252 	 * If the host wants to be called before the scan starts, but
253 	 * after the midlayer has set up ready for the scan, it can fill
254 	 * in this function.
255 	 *
256 	 * Status: OPTIONAL
257 	 */
258 	void (* scan_start)(struct Scsi_Host *);
259 
260 	/*
261 	 * Fill in this function to allow the queue depth of this host
262 	 * to be changeable (on a per device basis).  Returns either
263 	 * the current queue depth setting (may be different from what
264 	 * was passed in) or an error.  An error should only be
265 	 * returned if the requested depth is legal but the driver was
266 	 * unable to set it.  If the requested depth is illegal, the
267 	 * driver should set and return the closest legal queue depth.
268 	 *
269 	 * Status: OPTIONAL
270 	 */
271 	int (* change_queue_depth)(struct scsi_device *, int);
272 
273 	/*
274 	 * This functions lets the driver expose the queue mapping
275 	 * to the block layer.
276 	 *
277 	 * Status: OPTIONAL
278 	 */
279 	void (* map_queues)(struct Scsi_Host *shost);
280 
281 	/*
282 	 * SCSI interface of blk_poll - poll for IO completions.
283 	 * Only applicable if SCSI LLD exposes multiple h/w queues.
284 	 *
285 	 * Return value: Number of completed entries found.
286 	 *
287 	 * Status: OPTIONAL
288 	 */
289 	int (* mq_poll)(struct Scsi_Host *shost, unsigned int queue_num);
290 
291 	/*
292 	 * Check if scatterlists need to be padded for DMA draining.
293 	 *
294 	 * Status: OPTIONAL
295 	 */
296 	bool (* dma_need_drain)(struct request *rq);
297 
298 	/*
299 	 * This function determines the BIOS parameters for a given
300 	 * harddisk.  These tend to be numbers that are made up by
301 	 * the host adapter.  Parameters:
302 	 * size, device, list (heads, sectors, cylinders)
303 	 *
304 	 * Status: OPTIONAL
305 	 */
306 	int (* bios_param)(struct scsi_device *, struct block_device *,
307 			sector_t, int []);
308 
309 	/*
310 	 * This function is called when one or more partitions on the
311 	 * device reach beyond the end of the device.
312 	 *
313 	 * Status: OPTIONAL
314 	 */
315 	void (*unlock_native_capacity)(struct scsi_device *);
316 
317 	/*
318 	 * Can be used to export driver statistics and other infos to the
319 	 * world outside the kernel ie. userspace and it also provides an
320 	 * interface to feed the driver with information.
321 	 *
322 	 * Status: OBSOLETE
323 	 */
324 	int (*show_info)(struct seq_file *, struct Scsi_Host *);
325 	int (*write_info)(struct Scsi_Host *, char *, int);
326 
327 	/*
328 	 * This is an optional routine that allows the transport to become
329 	 * involved when a scsi io timer fires. The return value tells the
330 	 * timer routine how to finish the io timeout handling.
331 	 *
332 	 * Status: OPTIONAL
333 	 */
334 	enum blk_eh_timer_return (*eh_timed_out)(struct scsi_cmnd *);
335 	/*
336 	 * Optional routine that allows the transport to decide if a cmd
337 	 * is retryable. Return true if the transport is in a state the
338 	 * cmd should be retried on.
339 	 */
340 	bool (*eh_should_retry_cmd)(struct scsi_cmnd *scmd);
341 
342 	/* This is an optional routine that allows transport to initiate
343 	 * LLD adapter or firmware reset using sysfs attribute.
344 	 *
345 	 * Return values: 0 on success, -ve value on failure.
346 	 *
347 	 * Status: OPTIONAL
348 	 */
349 
350 	int (*host_reset)(struct Scsi_Host *shost, int reset_type);
351 #define SCSI_ADAPTER_RESET	1
352 #define SCSI_FIRMWARE_RESET	2
353 
354 
355 	/*
356 	 * Name of proc directory
357 	 */
358 	const char *proc_name;
359 
360 	/*
361 	 * Used to store the procfs directory if a driver implements the
362 	 * show_info method.
363 	 */
364 	struct proc_dir_entry *proc_dir;
365 
366 	/*
367 	 * This determines if we will use a non-interrupt driven
368 	 * or an interrupt driven scheme.  It is set to the maximum number
369 	 * of simultaneous commands a single hw queue in HBA will accept.
370 	 */
371 	int can_queue;
372 
373 	/*
374 	 * In many instances, especially where disconnect / reconnect are
375 	 * supported, our host also has an ID on the SCSI bus.  If this is
376 	 * the case, then it must be reserved.  Please set this_id to -1 if
377 	 * your setup is in single initiator mode, and the host lacks an
378 	 * ID.
379 	 */
380 	int this_id;
381 
382 	/*
383 	 * This determines the degree to which the host adapter is capable
384 	 * of scatter-gather.
385 	 */
386 	unsigned short sg_tablesize;
387 	unsigned short sg_prot_tablesize;
388 
389 	/*
390 	 * Set this if the host adapter has limitations beside segment count.
391 	 */
392 	unsigned int max_sectors;
393 
394 	/*
395 	 * Maximum size in bytes of a single segment.
396 	 */
397 	unsigned int max_segment_size;
398 
399 	/*
400 	 * DMA scatter gather segment boundary limit. A segment crossing this
401 	 * boundary will be split in two.
402 	 */
403 	unsigned long dma_boundary;
404 
405 	unsigned long virt_boundary_mask;
406 
407 	/*
408 	 * This specifies "machine infinity" for host templates which don't
409 	 * limit the transfer size.  Note this limit represents an absolute
410 	 * maximum, and may be over the transfer limits allowed for
411 	 * individual devices (e.g. 256 for SCSI-1).
412 	 */
413 #define SCSI_DEFAULT_MAX_SECTORS	1024
414 
415 	/*
416 	 * True if this host adapter can make good use of linked commands.
417 	 * This will allow more than one command to be queued to a given
418 	 * unit on a given host.  Set this to the maximum number of command
419 	 * blocks to be provided for each device.  Set this to 1 for one
420 	 * command block per lun, 2 for two, etc.  Do not set this to 0.
421 	 * You should make sure that the host adapter will do the right thing
422 	 * before you try setting this above 1.
423 	 */
424 	short cmd_per_lun;
425 
426 	/*
427 	 * present contains counter indicating how many boards of this
428 	 * type were found when we did the scan.
429 	 */
430 	unsigned char present;
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  */
522 enum 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 
532 struct 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 
shost_priv(struct Scsi_Host * shost)722 static inline void *shost_priv(struct Scsi_Host *shost)
723 {
724 	return (void *)shost->hostdata;
725 }
726 
727 int scsi_is_host_device(const struct device *);
728 
dev_to_shost(struct device * dev)729 static 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 
scsi_host_in_recovery(struct Scsi_Host * shost)739 static 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 
747 extern int scsi_queue_work(struct Scsi_Host *, struct work_struct *);
748 extern void scsi_flush_work(struct Scsi_Host *);
749 
750 extern struct Scsi_Host *scsi_host_alloc(struct scsi_host_template *, int);
751 extern int __must_check scsi_add_host_with_dma(struct Scsi_Host *,
752 					       struct device *,
753 					       struct device *);
754 extern void scsi_scan_host(struct Scsi_Host *);
755 extern void scsi_rescan_device(struct device *);
756 extern void scsi_remove_host(struct Scsi_Host *);
757 extern struct Scsi_Host *scsi_host_get(struct Scsi_Host *);
758 extern int scsi_host_busy(struct Scsi_Host *shost);
759 extern void scsi_host_put(struct Scsi_Host *t);
760 extern struct Scsi_Host *scsi_host_lookup(unsigned short);
761 extern const char *scsi_host_state_name(enum scsi_host_state);
762 extern void scsi_host_complete_all_commands(struct Scsi_Host *shost,
763 					    enum scsi_host_status status);
764 
scsi_add_host(struct Scsi_Host * host,struct device * dev)765 static inline int __must_check scsi_add_host(struct Scsi_Host *host,
766 					     struct device *dev)
767 {
768 	return scsi_add_host_with_dma(host, dev, dev);
769 }
770 
scsi_get_device(struct Scsi_Host * shost)771 static inline struct device *scsi_get_device(struct Scsi_Host *shost)
772 {
773         return shost->shost_gendev.parent;
774 }
775 
776 /**
777  * scsi_host_scan_allowed - Is scanning of this host allowed
778  * @shost:	Pointer to Scsi_Host.
779  **/
scsi_host_scan_allowed(struct Scsi_Host * shost)780 static inline int scsi_host_scan_allowed(struct Scsi_Host *shost)
781 {
782 	return shost->shost_state == SHOST_RUNNING ||
783 	       shost->shost_state == SHOST_RECOVERY;
784 }
785 
786 extern void scsi_unblock_requests(struct Scsi_Host *);
787 extern void scsi_block_requests(struct Scsi_Host *);
788 extern int scsi_host_block(struct Scsi_Host *shost);
789 extern int scsi_host_unblock(struct Scsi_Host *shost, int new_state);
790 
791 void scsi_host_busy_iter(struct Scsi_Host *,
792 			 bool (*fn)(struct scsi_cmnd *, void *), void *priv);
793 
794 struct class_container;
795 
796 /*
797  * DIF defines the exchange of protection information between
798  * initiator and SBC block device.
799  *
800  * DIX defines the exchange of protection information between OS and
801  * initiator.
802  */
803 enum scsi_host_prot_capabilities {
804 	SHOST_DIF_TYPE1_PROTECTION = 1 << 0, /* T10 DIF Type 1 */
805 	SHOST_DIF_TYPE2_PROTECTION = 1 << 1, /* T10 DIF Type 2 */
806 	SHOST_DIF_TYPE3_PROTECTION = 1 << 2, /* T10 DIF Type 3 */
807 
808 	SHOST_DIX_TYPE0_PROTECTION = 1 << 3, /* DIX between OS and HBA only */
809 	SHOST_DIX_TYPE1_PROTECTION = 1 << 4, /* DIX with DIF Type 1 */
810 	SHOST_DIX_TYPE2_PROTECTION = 1 << 5, /* DIX with DIF Type 2 */
811 	SHOST_DIX_TYPE3_PROTECTION = 1 << 6, /* DIX with DIF Type 3 */
812 };
813 
814 /*
815  * SCSI hosts which support the Data Integrity Extensions must
816  * indicate their capabilities by setting the prot_capabilities using
817  * this call.
818  */
scsi_host_set_prot(struct Scsi_Host * shost,unsigned int mask)819 static inline void scsi_host_set_prot(struct Scsi_Host *shost, unsigned int mask)
820 {
821 	shost->prot_capabilities = mask;
822 }
823 
scsi_host_get_prot(struct Scsi_Host * shost)824 static inline unsigned int scsi_host_get_prot(struct Scsi_Host *shost)
825 {
826 	return shost->prot_capabilities;
827 }
828 
scsi_host_prot_dma(struct Scsi_Host * shost)829 static inline int scsi_host_prot_dma(struct Scsi_Host *shost)
830 {
831 	return shost->prot_capabilities >= SHOST_DIX_TYPE0_PROTECTION;
832 }
833 
scsi_host_dif_capable(struct Scsi_Host * shost,unsigned int target_type)834 static inline unsigned int scsi_host_dif_capable(struct Scsi_Host *shost, unsigned int target_type)
835 {
836 	static unsigned char cap[] = { 0,
837 				       SHOST_DIF_TYPE1_PROTECTION,
838 				       SHOST_DIF_TYPE2_PROTECTION,
839 				       SHOST_DIF_TYPE3_PROTECTION };
840 
841 	if (target_type >= ARRAY_SIZE(cap))
842 		return 0;
843 
844 	return shost->prot_capabilities & cap[target_type] ? target_type : 0;
845 }
846 
scsi_host_dix_capable(struct Scsi_Host * shost,unsigned int target_type)847 static inline unsigned int scsi_host_dix_capable(struct Scsi_Host *shost, unsigned int target_type)
848 {
849 #if defined(CONFIG_BLK_DEV_INTEGRITY)
850 	static unsigned char cap[] = { SHOST_DIX_TYPE0_PROTECTION,
851 				       SHOST_DIX_TYPE1_PROTECTION,
852 				       SHOST_DIX_TYPE2_PROTECTION,
853 				       SHOST_DIX_TYPE3_PROTECTION };
854 
855 	if (target_type >= ARRAY_SIZE(cap))
856 		return 0;
857 
858 	return shost->prot_capabilities & cap[target_type];
859 #endif
860 	return 0;
861 }
862 
863 /*
864  * All DIX-capable initiators must support the T10-mandated CRC
865  * checksum.  Controllers can optionally implement the IP checksum
866  * scheme which has much lower impact on system performance.  Note
867  * that the main rationale for the checksum is to match integrity
868  * metadata with data.  Detecting bit errors are a job for ECC memory
869  * and buses.
870  */
871 
872 enum scsi_host_guard_type {
873 	SHOST_DIX_GUARD_CRC = 1 << 0,
874 	SHOST_DIX_GUARD_IP  = 1 << 1,
875 };
876 
scsi_host_set_guard(struct Scsi_Host * shost,unsigned char type)877 static inline void scsi_host_set_guard(struct Scsi_Host *shost, unsigned char type)
878 {
879 	shost->prot_guard_type = type;
880 }
881 
scsi_host_get_guard(struct Scsi_Host * shost)882 static inline unsigned char scsi_host_get_guard(struct Scsi_Host *shost)
883 {
884 	return shost->prot_guard_type;
885 }
886 
887 extern int scsi_host_set_state(struct Scsi_Host *, enum scsi_host_state);
888 
889 #endif /* _SCSI_SCSI_HOST_H */
890