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_host_cmd_pool;
20 struct scsi_target;
21 struct Scsi_Host;
22 struct scsi_transport_template;
23 
24 
25 #define SG_ALL	SG_CHUNK_SIZE
26 
27 #define MODE_UNKNOWN 0x00
28 #define MODE_INITIATOR 0x01
29 #define MODE_TARGET 0x02
30 
31 struct scsi_host_template {
32 	/*
33 	 * Put fields referenced in IO submission path together in
34 	 * same cacheline
35 	 */
36 
37 	/*
38 	 * Additional per-command data allocated for the driver.
39 	 */
40 	unsigned int cmd_size;
41 
42 	/*
43 	 * The queuecommand function is used to queue up a scsi
44 	 * command block to the LLDD.  When the driver finished
45 	 * processing the command the done callback is invoked.
46 	 *
47 	 * If queuecommand returns 0, then the driver has accepted the
48 	 * command.  It must also push it to the HBA if the scsi_cmnd
49 	 * flag SCMD_LAST is set, or if the driver does not implement
50 	 * commit_rqs.  The done() function must be called on the command
51 	 * when the driver has finished with it. (you may call done on the
52 	 * command before queuecommand returns, but in this case you
53 	 * *must* return 0 from queuecommand).
54 	 *
55 	 * Queuecommand may also reject the command, in which case it may
56 	 * not touch the command and must not call done() for it.
57 	 *
58 	 * There are two possible rejection returns:
59 	 *
60 	 *   SCSI_MLQUEUE_DEVICE_BUSY: Block this device temporarily, but
61 	 *   allow commands to other devices serviced by this host.
62 	 *
63 	 *   SCSI_MLQUEUE_HOST_BUSY: Block all devices served by this
64 	 *   host temporarily.
65 	 *
66          * For compatibility, any other non-zero return is treated the
67          * same as SCSI_MLQUEUE_HOST_BUSY.
68 	 *
69 	 * NOTE: "temporarily" means either until the next command for#
70 	 * this device/host completes, or a period of time determined by
71 	 * I/O pressure in the system if there are no other outstanding
72 	 * commands.
73 	 *
74 	 * STATUS: REQUIRED
75 	 */
76 	int (* queuecommand)(struct Scsi_Host *, struct scsi_cmnd *);
77 
78 	/*
79 	 * The commit_rqs function is used to trigger a hardware
80 	 * doorbell after some requests have been queued with
81 	 * queuecommand, when an error is encountered before sending
82 	 * the request with SCMD_LAST set.
83 	 *
84 	 * STATUS: OPTIONAL
85 	 */
86 	void (*commit_rqs)(struct Scsi_Host *, u16);
87 
88 	struct module *module;
89 	const char *name;
90 
91 	/*
92 	 * The info function will return whatever useful information the
93 	 * developer sees fit.  If not provided, then the name field will
94 	 * be used instead.
95 	 *
96 	 * Status: OPTIONAL
97 	 */
98 	const char *(*info)(struct Scsi_Host *);
99 
100 	/*
101 	 * Ioctl interface
102 	 *
103 	 * Status: OPTIONAL
104 	 */
105 	int (*ioctl)(struct scsi_device *dev, unsigned int cmd,
106 		     void __user *arg);
107 
108 
109 #ifdef CONFIG_COMPAT
110 	/*
111 	 * Compat handler. Handle 32bit ABI.
112 	 * When unknown ioctl is passed return -ENOIOCTLCMD.
113 	 *
114 	 * Status: OPTIONAL
115 	 */
116 	int (*compat_ioctl)(struct scsi_device *dev, unsigned int cmd,
117 			    void __user *arg);
118 #endif
119 
120 	int (*init_cmd_priv)(struct Scsi_Host *shost, struct scsi_cmnd *cmd);
121 	int (*exit_cmd_priv)(struct Scsi_Host *shost, struct scsi_cmnd *cmd);
122 
123 	/*
124 	 * This is an error handling strategy routine.  You don't need to
125 	 * define one of these if you don't want to - there is a default
126 	 * routine that is present that should work in most cases.  For those
127 	 * driver authors that have the inclination and ability to write their
128 	 * own strategy routine, this is where it is specified.  Note - the
129 	 * strategy routine is *ALWAYS* run in the context of the kernel eh
130 	 * thread.  Thus you are guaranteed to *NOT* be in an interrupt
131 	 * handler when you execute this, and you are also guaranteed to
132 	 * *NOT* have any other commands being queued while you are in the
133 	 * strategy routine. When you return from this function, operations
134 	 * return to normal.
135 	 *
136 	 * See scsi_error.c scsi_unjam_host for additional comments about
137 	 * what this function should and should not be attempting to do.
138 	 *
139 	 * Status: REQUIRED	(at least one of them)
140 	 */
141 	int (* eh_abort_handler)(struct scsi_cmnd *);
142 	int (* eh_device_reset_handler)(struct scsi_cmnd *);
143 	int (* eh_target_reset_handler)(struct scsi_cmnd *);
144 	int (* eh_bus_reset_handler)(struct scsi_cmnd *);
145 	int (* eh_host_reset_handler)(struct scsi_cmnd *);
146 
147 	/*
148 	 * Before the mid layer attempts to scan for a new device where none
149 	 * currently exists, it will call this entry in your driver.  Should
150 	 * your driver need to allocate any structs or perform any other init
151 	 * items in order to send commands to a currently unused target/lun
152 	 * combo, then this is where you can perform those allocations.  This
153 	 * is specifically so that drivers won't have to perform any kind of
154 	 * "is this a new device" checks in their queuecommand routine,
155 	 * thereby making the hot path a bit quicker.
156 	 *
157 	 * Return values: 0 on success, non-0 on failure
158 	 *
159 	 * Deallocation:  If we didn't find any devices at this ID, you will
160 	 * get an immediate call to slave_destroy().  If we find something
161 	 * here then you will get a call to slave_configure(), then the
162 	 * device will be used for however long it is kept around, then when
163 	 * the device is removed from the system (or * possibly at reboot
164 	 * time), you will then get a call to slave_destroy().  This is
165 	 * assuming you implement slave_configure and slave_destroy.
166 	 * However, if you allocate memory and hang it off the device struct,
167 	 * then you must implement the slave_destroy() routine at a minimum
168 	 * in order to avoid leaking memory
169 	 * each time a device is tore down.
170 	 *
171 	 * Status: OPTIONAL
172 	 */
173 	int (* slave_alloc)(struct scsi_device *);
174 
175 	/*
176 	 * Once the device has responded to an INQUIRY and we know the
177 	 * device is online, we call into the low level driver with the
178 	 * struct scsi_device *.  If the low level device driver implements
179 	 * this function, it *must* perform the task of setting the queue
180 	 * depth on the device.  All other tasks are optional and depend
181 	 * on what the driver supports and various implementation details.
182 	 *
183 	 * Things currently recommended to be handled at this time include:
184 	 *
185 	 * 1.  Setting the device queue depth.  Proper setting of this is
186 	 *     described in the comments for scsi_change_queue_depth.
187 	 * 2.  Determining if the device supports the various synchronous
188 	 *     negotiation protocols.  The device struct will already have
189 	 *     responded to INQUIRY and the results of the standard items
190 	 *     will have been shoved into the various device flag bits, eg.
191 	 *     device->sdtr will be true if the device supports SDTR messages.
192 	 * 3.  Allocating command structs that the device will need.
193 	 * 4.  Setting the default timeout on this device (if needed).
194 	 * 5.  Anything else the low level driver might want to do on a device
195 	 *     specific setup basis...
196 	 * 6.  Return 0 on success, non-0 on error.  The device will be marked
197 	 *     as offline on error so that no access will occur.  If you return
198 	 *     non-0, your slave_destroy routine will never get called for this
199 	 *     device, so don't leave any loose memory hanging around, clean
200 	 *     up after yourself before returning non-0
201 	 *
202 	 * Status: OPTIONAL
203 	 */
204 	int (* slave_configure)(struct scsi_device *);
205 
206 	/*
207 	 * Immediately prior to deallocating the device and after all activity
208 	 * has ceased the mid layer calls this point so that the low level
209 	 * driver may completely detach itself from the scsi device and vice
210 	 * versa.  The low level driver is responsible for freeing any memory
211 	 * it allocated in the slave_alloc or slave_configure calls.
212 	 *
213 	 * Status: OPTIONAL
214 	 */
215 	void (* slave_destroy)(struct scsi_device *);
216 
217 	/*
218 	 * Before the mid layer attempts to scan for a new device attached
219 	 * to a target where no target currently exists, it will call this
220 	 * entry in your driver.  Should your driver need to allocate any
221 	 * structs or perform any other init items in order to send commands
222 	 * to a currently unused target, then this is where you can perform
223 	 * those allocations.
224 	 *
225 	 * Return values: 0 on success, non-0 on failure
226 	 *
227 	 * Status: OPTIONAL
228 	 */
229 	int (* target_alloc)(struct scsi_target *);
230 
231 	/*
232 	 * Immediately prior to deallocating the target structure, and
233 	 * after all activity to attached scsi devices has ceased, the
234 	 * midlayer calls this point so that the driver may deallocate
235 	 * and terminate any references to the target.
236 	 *
237 	 * Status: OPTIONAL
238 	 */
239 	void (* target_destroy)(struct scsi_target *);
240 
241 	/*
242 	 * If a host has the ability to discover targets on its own instead
243 	 * of scanning the entire bus, it can fill in this function and
244 	 * call scsi_scan_host().  This function will be called periodically
245 	 * until it returns 1 with the scsi_host and the elapsed time of
246 	 * the scan in jiffies.
247 	 *
248 	 * Status: OPTIONAL
249 	 */
250 	int (* scan_finished)(struct Scsi_Host *, unsigned long);
251 
252 	/*
253 	 * If the host wants to be called before the scan starts, but
254 	 * after the midlayer has set up ready for the scan, it can fill
255 	 * in this function.
256 	 *
257 	 * Status: OPTIONAL
258 	 */
259 	void (* scan_start)(struct Scsi_Host *);
260 
261 	/*
262 	 * Fill in this function to allow the queue depth of this host
263 	 * to be changeable (on a per device basis).  Returns either
264 	 * the current queue depth setting (may be different from what
265 	 * was passed in) or an error.  An error should only be
266 	 * returned if the requested depth is legal but the driver was
267 	 * unable to set it.  If the requested depth is illegal, the
268 	 * driver should set and return the closest legal queue depth.
269 	 *
270 	 * Status: OPTIONAL
271 	 */
272 	int (* change_queue_depth)(struct scsi_device *, int);
273 
274 	/*
275 	 * This functions lets the driver expose the queue mapping
276 	 * to the block layer.
277 	 *
278 	 * Status: OPTIONAL
279 	 */
280 	int (* map_queues)(struct Scsi_Host *shost);
281 
282 	/*
283 	 * SCSI interface of blk_poll - poll for IO completions.
284 	 * Only applicable if SCSI LLD exposes multiple h/w queues.
285 	 *
286 	 * Return value: Number of completed entries found.
287 	 *
288 	 * Status: OPTIONAL
289 	 */
290 	int (* mq_poll)(struct Scsi_Host *shost, unsigned int queue_num);
291 
292 	/*
293 	 * Check if scatterlists need to be padded for DMA draining.
294 	 *
295 	 * Status: OPTIONAL
296 	 */
297 	bool (* dma_need_drain)(struct request *rq);
298 
299 	/*
300 	 * This function determines the BIOS parameters for a given
301 	 * harddisk.  These tend to be numbers that are made up by
302 	 * the host adapter.  Parameters:
303 	 * size, device, list (heads, sectors, cylinders)
304 	 *
305 	 * Status: OPTIONAL
306 	 */
307 	int (* bios_param)(struct scsi_device *, struct block_device *,
308 			sector_t, int []);
309 
310 	/*
311 	 * This function is called when one or more partitions on the
312 	 * device reach beyond the end of the device.
313 	 *
314 	 * Status: OPTIONAL
315 	 */
316 	void (*unlock_native_capacity)(struct scsi_device *);
317 
318 	/*
319 	 * Can be used to export driver statistics and other infos to the
320 	 * world outside the kernel ie. userspace and it also provides an
321 	 * interface to feed the driver with information.
322 	 *
323 	 * Status: OBSOLETE
324 	 */
325 	int (*show_info)(struct seq_file *, struct Scsi_Host *);
326 	int (*write_info)(struct Scsi_Host *, char *, int);
327 
328 	/*
329 	 * This is an optional routine that allows the transport to become
330 	 * involved when a scsi io timer fires. The return value tells the
331 	 * timer routine how to finish the io timeout handling.
332 	 *
333 	 * Status: OPTIONAL
334 	 */
335 	enum blk_eh_timer_return (*eh_timed_out)(struct scsi_cmnd *);
336 	/*
337 	 * Optional routine that allows the transport to decide if a cmd
338 	 * is retryable. Return true if the transport is in a state the
339 	 * cmd should be retried on.
340 	 */
341 	bool (*eh_should_retry_cmd)(struct scsi_cmnd *scmd);
342 
343 	/* This is an optional routine that allows transport to initiate
344 	 * LLD adapter or firmware reset using sysfs attribute.
345 	 *
346 	 * Return values: 0 on success, -ve value on failure.
347 	 *
348 	 * Status: OPTIONAL
349 	 */
350 
351 	int (*host_reset)(struct Scsi_Host *shost, int reset_type);
352 #define SCSI_ADAPTER_RESET	1
353 #define SCSI_FIRMWARE_RESET	2
354 
355 
356 	/*
357 	 * Name of proc directory
358 	 */
359 	const char *proc_name;
360 
361 	/*
362 	 * Used to store the procfs directory if a driver implements the
363 	 * show_info method.
364 	 */
365 	struct proc_dir_entry *proc_dir;
366 
367 	/*
368 	 * This determines if we will use a non-interrupt driven
369 	 * or an interrupt driven scheme.  It is set to the maximum number
370 	 * of simultaneous commands a single hw queue in HBA will accept.
371 	 */
372 	int can_queue;
373 
374 	/*
375 	 * In many instances, especially where disconnect / reconnect are
376 	 * supported, our host also has an ID on the SCSI bus.  If this is
377 	 * the case, then it must be reserved.  Please set this_id to -1 if
378 	 * your setup is in single initiator mode, and the host lacks an
379 	 * ID.
380 	 */
381 	int this_id;
382 
383 	/*
384 	 * This determines the degree to which the host adapter is capable
385 	 * of scatter-gather.
386 	 */
387 	unsigned short sg_tablesize;
388 	unsigned short sg_prot_tablesize;
389 
390 	/*
391 	 * Set this if the host adapter has limitations beside segment count.
392 	 */
393 	unsigned int max_sectors;
394 
395 	/*
396 	 * Maximum size in bytes of a single segment.
397 	 */
398 	unsigned int max_segment_size;
399 
400 	/*
401 	 * DMA scatter gather segment boundary limit. A segment crossing this
402 	 * boundary will be split in two.
403 	 */
404 	unsigned long dma_boundary;
405 
406 	unsigned long virt_boundary_mask;
407 
408 	/*
409 	 * This specifies "machine infinity" for host templates which don't
410 	 * limit the transfer size.  Note this limit represents an absolute
411 	 * maximum, and may be over the transfer limits allowed for
412 	 * individual devices (e.g. 256 for SCSI-1).
413 	 */
414 #define SCSI_DEFAULT_MAX_SECTORS	1024
415 
416 	/*
417 	 * True if this host adapter can make good use of linked commands.
418 	 * This will allow more than one command to be queued to a given
419 	 * unit on a given host.  Set this to the maximum number of command
420 	 * blocks to be provided for each device.  Set this to 1 for one
421 	 * command block per lun, 2 for two, etc.  Do not set this to 0.
422 	 * You should make sure that the host adapter will do the right thing
423 	 * before you try setting this above 1.
424 	 */
425 	short cmd_per_lun;
426 
427 	/*
428 	 * present contains counter indicating how many boards of this
429 	 * type were found when we did the scan.
430 	 */
431 	unsigned char present;
432 
433 	/* If use block layer to manage tags, this is tag allocation policy */
434 	int tag_alloc_policy;
435 
436 	/*
437 	 * Track QUEUE_FULL events and reduce queue depth on demand.
438 	 */
439 	unsigned track_queue_depth:1;
440 
441 	/*
442 	 * This specifies the mode that a LLD supports.
443 	 */
444 	unsigned supported_mode:2;
445 
446 	/*
447 	 * True for emulated SCSI host adapters (e.g. ATAPI).
448 	 */
449 	unsigned emulated:1;
450 
451 	/*
452 	 * True if the low-level driver performs its own reset-settle delays.
453 	 */
454 	unsigned skip_settle_delay:1;
455 
456 	/* True if the controller does not support WRITE SAME */
457 	unsigned no_write_same:1;
458 
459 	/* True if the host uses host-wide tagspace */
460 	unsigned host_tagset:1;
461 
462 	/*
463 	 * Countdown for host blocking with no commands outstanding.
464 	 */
465 	unsigned int max_host_blocked;
466 
467 	/*
468 	 * Default value for the blocking.  If the queue is empty,
469 	 * host_blocked counts down in the request_fn until it restarts
470 	 * host operations as zero is reached.
471 	 *
472 	 * FIXME: This should probably be a value in the template
473 	 */
474 #define SCSI_DEFAULT_HOST_BLOCKED	7
475 
476 	/*
477 	 * Pointer to the SCSI host sysfs attribute groups, NULL terminated.
478 	 */
479 	const struct attribute_group **shost_groups;
480 
481 	/*
482 	 * Pointer to the SCSI device attribute groups for this host,
483 	 * NULL terminated.
484 	 */
485 	const struct attribute_group **sdev_groups;
486 
487 	/*
488 	 * Vendor Identifier associated with the host
489 	 *
490 	 * Note: When specifying vendor_id, be sure to read the
491 	 *   Vendor Type and ID formatting requirements specified in
492 	 *   scsi_netlink.h
493 	 */
494 	u64 vendor_id;
495 
496 	struct scsi_host_cmd_pool *cmd_pool;
497 
498 	/* Delay for runtime autosuspend */
499 	int rpm_autosuspend_delay;
500 };
501 
502 /*
503  * Temporary #define for host lock push down. Can be removed when all
504  * drivers have been updated to take advantage of unlocked
505  * queuecommand.
506  *
507  */
508 #define DEF_SCSI_QCMD(func_name) \
509 	int func_name(struct Scsi_Host *shost, struct scsi_cmnd *cmd)	\
510 	{								\
511 		unsigned long irq_flags;				\
512 		int rc;							\
513 		spin_lock_irqsave(shost->host_lock, irq_flags);		\
514 		rc = func_name##_lck(cmd);				\
515 		spin_unlock_irqrestore(shost->host_lock, irq_flags);	\
516 		return rc;						\
517 	}
518 
519 
520 /*
521  * shost state: If you alter this, you also need to alter scsi_sysfs.c
522  * (for the ascii descriptions) and the state model enforcer:
523  * scsi_host_set_state()
524  */
525 enum scsi_host_state {
526 	SHOST_CREATED = 1,
527 	SHOST_RUNNING,
528 	SHOST_CANCEL,
529 	SHOST_DEL,
530 	SHOST_RECOVERY,
531 	SHOST_CANCEL_RECOVERY,
532 	SHOST_DEL_RECOVERY,
533 };
534 
535 struct Scsi_Host {
536 	/*
537 	 * __devices is protected by the host_lock, but you should
538 	 * usually use scsi_device_lookup / shost_for_each_device
539 	 * to access it and don't care about locking yourself.
540 	 * In the rare case of being in irq context you can use
541 	 * their __ prefixed variants with the lock held. NEVER
542 	 * access this list directly from a driver.
543 	 */
544 	struct list_head	__devices;
545 	struct list_head	__targets;
546 
547 	struct list_head	starved_list;
548 
549 	spinlock_t		default_lock;
550 	spinlock_t		*host_lock;
551 
552 	struct mutex		scan_mutex;/* serialize scanning activity */
553 
554 	struct list_head	eh_abort_list;
555 	struct list_head	eh_cmd_q;
556 	struct task_struct    * ehandler;  /* Error recovery thread. */
557 	struct completion     * eh_action; /* Wait for specific actions on the
558 					      host. */
559 	wait_queue_head_t       host_wait;
560 	struct scsi_host_template *hostt;
561 	struct scsi_transport_template *transportt;
562 
563 	/* Area to keep a shared tag map */
564 	struct blk_mq_tag_set	tag_set;
565 
566 	atomic_t host_blocked;
567 
568 	unsigned int host_failed;	   /* commands that failed.
569 					      protected by host_lock */
570 	unsigned int host_eh_scheduled;    /* EH scheduled without command */
571 
572 	unsigned int host_no;  /* Used for IOCTL_GET_IDLUN, /proc/scsi et al. */
573 
574 	/* next two fields are used to bound the time spent in error handling */
575 	int eh_deadline;
576 	unsigned long last_reset;
577 
578 
579 	/*
580 	 * These three parameters can be used to allow for wide scsi,
581 	 * and for host adapters that support multiple busses
582 	 * The last two should be set to 1 more than the actual max id
583 	 * or lun (e.g. 8 for SCSI parallel systems).
584 	 */
585 	unsigned int max_channel;
586 	unsigned int max_id;
587 	u64 max_lun;
588 
589 	/*
590 	 * This is a unique identifier that must be assigned so that we
591 	 * have some way of identifying each detected host adapter properly
592 	 * and uniquely.  For hosts that do not support more than one card
593 	 * in the system at one time, this does not need to be set.  It is
594 	 * initialized to 0 in scsi_register.
595 	 */
596 	unsigned int unique_id;
597 
598 	/*
599 	 * The maximum length of SCSI commands that this host can accept.
600 	 * Probably 12 for most host adapters, but could be 16 for others.
601 	 * or 260 if the driver supports variable length cdbs.
602 	 * For drivers that don't set this field, a value of 12 is
603 	 * assumed.
604 	 */
605 	unsigned short max_cmd_len;
606 
607 	int this_id;
608 	int can_queue;
609 	short cmd_per_lun;
610 	short unsigned int sg_tablesize;
611 	short unsigned int sg_prot_tablesize;
612 	unsigned int max_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 	 * The array size 3 provides space for one attribute group defined by
696 	 * the SCSI core, one attribute group defined by the SCSI LLD and one
697 	 * terminating NULL pointer.
698 	 */
699 	const struct attribute_group *shost_dev_attr_groups[3];
700 
701 	/*
702 	 * Points to the transport data (if any) which is allocated
703 	 * separately
704 	 */
705 	void *shost_data;
706 
707 	/*
708 	 * Points to the physical bus device we'd use to do DMA
709 	 * Needed just in case we have virtual hosts.
710 	 */
711 	struct device *dma_dev;
712 
713 	/*
714 	 * We should ensure that this is aligned, both for better performance
715 	 * and also because some compilers (m68k) don't automatically force
716 	 * alignment to a long boundary.
717 	 */
718 	unsigned long hostdata[]  /* Used for storage of host specific stuff */
719 		__attribute__ ((aligned (sizeof(unsigned long))));
720 };
721 
722 #define		class_to_shost(d)	\
723 	container_of(d, struct Scsi_Host, shost_dev)
724 
725 #define shost_printk(prefix, shost, fmt, a...)	\
726 	dev_printk(prefix, &(shost)->shost_gendev, fmt, ##a)
727 
shost_priv(struct Scsi_Host * shost)728 static inline void *shost_priv(struct Scsi_Host *shost)
729 {
730 	return (void *)shost->hostdata;
731 }
732 
733 int scsi_is_host_device(const struct device *);
734 
dev_to_shost(struct device * dev)735 static inline struct Scsi_Host *dev_to_shost(struct device *dev)
736 {
737 	while (!scsi_is_host_device(dev)) {
738 		if (!dev->parent)
739 			return NULL;
740 		dev = dev->parent;
741 	}
742 	return container_of(dev, struct Scsi_Host, shost_gendev);
743 }
744 
scsi_host_in_recovery(struct Scsi_Host * shost)745 static inline int scsi_host_in_recovery(struct Scsi_Host *shost)
746 {
747 	return shost->shost_state == SHOST_RECOVERY ||
748 		shost->shost_state == SHOST_CANCEL_RECOVERY ||
749 		shost->shost_state == SHOST_DEL_RECOVERY ||
750 		shost->tmf_in_progress;
751 }
752 
753 extern int scsi_queue_work(struct Scsi_Host *, struct work_struct *);
754 extern void scsi_flush_work(struct Scsi_Host *);
755 
756 extern struct Scsi_Host *scsi_host_alloc(struct scsi_host_template *, int);
757 extern int __must_check scsi_add_host_with_dma(struct Scsi_Host *,
758 					       struct device *,
759 					       struct device *);
760 extern void scsi_scan_host(struct Scsi_Host *);
761 extern void scsi_rescan_device(struct device *);
762 extern void scsi_remove_host(struct Scsi_Host *);
763 extern struct Scsi_Host *scsi_host_get(struct Scsi_Host *);
764 extern int scsi_host_busy(struct Scsi_Host *shost);
765 extern void scsi_host_put(struct Scsi_Host *t);
766 extern struct Scsi_Host *scsi_host_lookup(unsigned short);
767 extern const char *scsi_host_state_name(enum scsi_host_state);
768 extern void scsi_host_complete_all_commands(struct Scsi_Host *shost,
769 					    enum scsi_host_status status);
770 
scsi_add_host(struct Scsi_Host * host,struct device * dev)771 static 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 
scsi_get_device(struct Scsi_Host * shost)777 static 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  **/
scsi_host_scan_allowed(struct Scsi_Host * shost)786 static 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 
792 extern void scsi_unblock_requests(struct Scsi_Host *);
793 extern void scsi_block_requests(struct Scsi_Host *);
794 extern int scsi_host_block(struct Scsi_Host *shost);
795 extern int scsi_host_unblock(struct Scsi_Host *shost, int new_state);
796 
797 void scsi_host_busy_iter(struct Scsi_Host *,
798 			 bool (*fn)(struct scsi_cmnd *, void *, bool), void *priv);
799 
800 struct 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  */
809 enum 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  */
scsi_host_set_prot(struct Scsi_Host * shost,unsigned int mask)825 static inline void scsi_host_set_prot(struct Scsi_Host *shost, unsigned int mask)
826 {
827 	shost->prot_capabilities = mask;
828 }
829 
scsi_host_get_prot(struct Scsi_Host * shost)830 static inline unsigned int scsi_host_get_prot(struct Scsi_Host *shost)
831 {
832 	return shost->prot_capabilities;
833 }
834 
scsi_host_prot_dma(struct Scsi_Host * shost)835 static inline int scsi_host_prot_dma(struct Scsi_Host *shost)
836 {
837 	return shost->prot_capabilities >= SHOST_DIX_TYPE0_PROTECTION;
838 }
839 
scsi_host_dif_capable(struct Scsi_Host * shost,unsigned int target_type)840 static 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 
scsi_host_dix_capable(struct Scsi_Host * shost,unsigned int target_type)853 static 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 
878 enum scsi_host_guard_type {
879 	SHOST_DIX_GUARD_CRC = 1 << 0,
880 	SHOST_DIX_GUARD_IP  = 1 << 1,
881 };
882 
scsi_host_set_guard(struct Scsi_Host * shost,unsigned char type)883 static inline void scsi_host_set_guard(struct Scsi_Host *shost, unsigned char type)
884 {
885 	shost->prot_guard_type = type;
886 }
887 
scsi_host_get_guard(struct Scsi_Host * shost)888 static inline unsigned char scsi_host_get_guard(struct Scsi_Host *shost)
889 {
890 	return shost->prot_guard_type;
891 }
892 
893 extern int scsi_host_set_state(struct Scsi_Host *, enum scsi_host_state);
894 
895 #endif /* _SCSI_SCSI_HOST_H */
896