xref: /openbmc/linux/include/scsi/scsi_host.h (revision 7f877908)
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_host_cmd_pool;
23 struct scsi_transport_template;
24 
25 
26 #define SG_ALL	SG_CHUNK_SIZE
27 
28 #define MODE_UNKNOWN 0x00
29 #define MODE_INITIATOR 0x01
30 #define MODE_TARGET 0x02
31 
32 struct scsi_host_template {
33 	struct module *module;
34 	const char *name;
35 
36 	/*
37 	 * The info function will return whatever useful information the
38 	 * developer sees fit.  If not provided, then the name field will
39 	 * be used instead.
40 	 *
41 	 * Status: OPTIONAL
42 	 */
43 	const char *(* info)(struct Scsi_Host *);
44 
45 	/*
46 	 * Ioctl interface
47 	 *
48 	 * Status: OPTIONAL
49 	 */
50 	int (*ioctl)(struct scsi_device *dev, unsigned int cmd,
51 		     void __user *arg);
52 
53 
54 #ifdef CONFIG_COMPAT
55 	/*
56 	 * Compat handler. Handle 32bit ABI.
57 	 * When unknown ioctl is passed return -ENOIOCTLCMD.
58 	 *
59 	 * Status: OPTIONAL
60 	 */
61 	int (*compat_ioctl)(struct scsi_device *dev, unsigned int cmd,
62 			    void __user *arg);
63 #endif
64 
65 	int (*init_cmd_priv)(struct Scsi_Host *shost, struct scsi_cmnd *cmd);
66 	int (*exit_cmd_priv)(struct Scsi_Host *shost, struct scsi_cmnd *cmd);
67 
68 	/*
69 	 * The queuecommand function is used to queue up a scsi
70 	 * command block to the LLDD.  When the driver finished
71 	 * processing the command the done callback is invoked.
72 	 *
73 	 * If queuecommand returns 0, then the driver has accepted the
74 	 * command.  It must also push it to the HBA if the scsi_cmnd
75 	 * flag SCMD_LAST is set, or if the driver does not implement
76 	 * commit_rqs.  The done() function must be called on the command
77 	 * when the driver has finished with it. (you may call done on the
78 	 * command before queuecommand returns, but in this case you
79 	 * *must* return 0 from queuecommand).
80 	 *
81 	 * Queuecommand may also reject the command, in which case it may
82 	 * not touch the command and must not call done() for it.
83 	 *
84 	 * There are two possible rejection returns:
85 	 *
86 	 *   SCSI_MLQUEUE_DEVICE_BUSY: Block this device temporarily, but
87 	 *   allow commands to other devices serviced by this host.
88 	 *
89 	 *   SCSI_MLQUEUE_HOST_BUSY: Block all devices served by this
90 	 *   host temporarily.
91 	 *
92          * For compatibility, any other non-zero return is treated the
93          * same as SCSI_MLQUEUE_HOST_BUSY.
94 	 *
95 	 * NOTE: "temporarily" means either until the next command for#
96 	 * this device/host completes, or a period of time determined by
97 	 * I/O pressure in the system if there are no other outstanding
98 	 * commands.
99 	 *
100 	 * STATUS: REQUIRED
101 	 */
102 	int (* queuecommand)(struct Scsi_Host *, struct scsi_cmnd *);
103 
104 	/*
105 	 * The commit_rqs function is used to trigger a hardware
106 	 * doorbell after some requests have been queued with
107 	 * queuecommand, when an error is encountered before sending
108 	 * the request with SCMD_LAST set.
109 	 *
110 	 * STATUS: OPTIONAL
111 	 */
112 	void (*commit_rqs)(struct Scsi_Host *, u16);
113 
114 	/*
115 	 * This is an error handling strategy routine.  You don't need to
116 	 * define one of these if you don't want to - there is a default
117 	 * routine that is present that should work in most cases.  For those
118 	 * driver authors that have the inclination and ability to write their
119 	 * own strategy routine, this is where it is specified.  Note - the
120 	 * strategy routine is *ALWAYS* run in the context of the kernel eh
121 	 * thread.  Thus you are guaranteed to *NOT* be in an interrupt
122 	 * handler when you execute this, and you are also guaranteed to
123 	 * *NOT* have any other commands being queued while you are in the
124 	 * strategy routine. When you return from this function, operations
125 	 * return to normal.
126 	 *
127 	 * See scsi_error.c scsi_unjam_host for additional comments about
128 	 * what this function should and should not be attempting to do.
129 	 *
130 	 * Status: REQUIRED	(at least one of them)
131 	 */
132 	int (* eh_abort_handler)(struct scsi_cmnd *);
133 	int (* eh_device_reset_handler)(struct scsi_cmnd *);
134 	int (* eh_target_reset_handler)(struct scsi_cmnd *);
135 	int (* eh_bus_reset_handler)(struct scsi_cmnd *);
136 	int (* eh_host_reset_handler)(struct scsi_cmnd *);
137 
138 	/*
139 	 * Before the mid layer attempts to scan for a new device where none
140 	 * currently exists, it will call this entry in your driver.  Should
141 	 * your driver need to allocate any structs or perform any other init
142 	 * items in order to send commands to a currently unused target/lun
143 	 * combo, then this is where you can perform those allocations.  This
144 	 * is specifically so that drivers won't have to perform any kind of
145 	 * "is this a new device" checks in their queuecommand routine,
146 	 * thereby making the hot path a bit quicker.
147 	 *
148 	 * Return values: 0 on success, non-0 on failure
149 	 *
150 	 * Deallocation:  If we didn't find any devices at this ID, you will
151 	 * get an immediate call to slave_destroy().  If we find something
152 	 * here then you will get a call to slave_configure(), then the
153 	 * device will be used for however long it is kept around, then when
154 	 * the device is removed from the system (or * possibly at reboot
155 	 * time), you will then get a call to slave_destroy().  This is
156 	 * assuming you implement slave_configure and slave_destroy.
157 	 * However, if you allocate memory and hang it off the device struct,
158 	 * then you must implement the slave_destroy() routine at a minimum
159 	 * in order to avoid leaking memory
160 	 * each time a device is tore down.
161 	 *
162 	 * Status: OPTIONAL
163 	 */
164 	int (* slave_alloc)(struct scsi_device *);
165 
166 	/*
167 	 * Once the device has responded to an INQUIRY and we know the
168 	 * device is online, we call into the low level driver with the
169 	 * struct scsi_device *.  If the low level device driver implements
170 	 * this function, it *must* perform the task of setting the queue
171 	 * depth on the device.  All other tasks are optional and depend
172 	 * on what the driver supports and various implementation details.
173 	 *
174 	 * Things currently recommended to be handled at this time include:
175 	 *
176 	 * 1.  Setting the device queue depth.  Proper setting of this is
177 	 *     described in the comments for scsi_change_queue_depth.
178 	 * 2.  Determining if the device supports the various synchronous
179 	 *     negotiation protocols.  The device struct will already have
180 	 *     responded to INQUIRY and the results of the standard items
181 	 *     will have been shoved into the various device flag bits, eg.
182 	 *     device->sdtr will be true if the device supports SDTR messages.
183 	 * 3.  Allocating command structs that the device will need.
184 	 * 4.  Setting the default timeout on this device (if needed).
185 	 * 5.  Anything else the low level driver might want to do on a device
186 	 *     specific setup basis...
187 	 * 6.  Return 0 on success, non-0 on error.  The device will be marked
188 	 *     as offline on error so that no access will occur.  If you return
189 	 *     non-0, your slave_destroy routine will never get called for this
190 	 *     device, so don't leave any loose memory hanging around, clean
191 	 *     up after yourself before returning non-0
192 	 *
193 	 * Status: OPTIONAL
194 	 */
195 	int (* slave_configure)(struct scsi_device *);
196 
197 	/*
198 	 * Immediately prior to deallocating the device and after all activity
199 	 * has ceased the mid layer calls this point so that the low level
200 	 * driver may completely detach itself from the scsi device and vice
201 	 * versa.  The low level driver is responsible for freeing any memory
202 	 * it allocated in the slave_alloc or slave_configure calls.
203 	 *
204 	 * Status: OPTIONAL
205 	 */
206 	void (* slave_destroy)(struct scsi_device *);
207 
208 	/*
209 	 * Before the mid layer attempts to scan for a new device attached
210 	 * to a target where no target currently exists, it will call this
211 	 * entry in your driver.  Should your driver need to allocate any
212 	 * structs or perform any other init items in order to send commands
213 	 * to a currently unused target, then this is where you can perform
214 	 * those allocations.
215 	 *
216 	 * Return values: 0 on success, non-0 on failure
217 	 *
218 	 * Status: OPTIONAL
219 	 */
220 	int (* target_alloc)(struct scsi_target *);
221 
222 	/*
223 	 * Immediately prior to deallocating the target structure, and
224 	 * after all activity to attached scsi devices has ceased, the
225 	 * midlayer calls this point so that the driver may deallocate
226 	 * and terminate any references to the target.
227 	 *
228 	 * Status: OPTIONAL
229 	 */
230 	void (* target_destroy)(struct scsi_target *);
231 
232 	/*
233 	 * If a host has the ability to discover targets on its own instead
234 	 * of scanning the entire bus, it can fill in this function and
235 	 * call scsi_scan_host().  This function will be called periodically
236 	 * until it returns 1 with the scsi_host and the elapsed time of
237 	 * the scan in jiffies.
238 	 *
239 	 * Status: OPTIONAL
240 	 */
241 	int (* scan_finished)(struct Scsi_Host *, unsigned long);
242 
243 	/*
244 	 * If the host wants to be called before the scan starts, but
245 	 * after the midlayer has set up ready for the scan, it can fill
246 	 * in this function.
247 	 *
248 	 * Status: OPTIONAL
249 	 */
250 	void (* scan_start)(struct Scsi_Host *);
251 
252 	/*
253 	 * Fill in this function to allow the queue depth of this host
254 	 * to be changeable (on a per device basis).  Returns either
255 	 * the current queue depth setting (may be different from what
256 	 * was passed in) or an error.  An error should only be
257 	 * returned if the requested depth is legal but the driver was
258 	 * unable to set it.  If the requested depth is illegal, the
259 	 * driver should set and return the closest legal queue depth.
260 	 *
261 	 * Status: OPTIONAL
262 	 */
263 	int (* change_queue_depth)(struct scsi_device *, int);
264 
265 	/*
266 	 * This functions lets the driver expose the queue mapping
267 	 * to the block layer.
268 	 *
269 	 * Status: OPTIONAL
270 	 */
271 	int (* map_queues)(struct Scsi_Host *shost);
272 
273 	/*
274 	 * This function determines the BIOS parameters for a given
275 	 * harddisk.  These tend to be numbers that are made up by
276 	 * the host adapter.  Parameters:
277 	 * size, device, list (heads, sectors, cylinders)
278 	 *
279 	 * Status: OPTIONAL
280 	 */
281 	int (* bios_param)(struct scsi_device *, struct block_device *,
282 			sector_t, int []);
283 
284 	/*
285 	 * This function is called when one or more partitions on the
286 	 * device reach beyond the end of the device.
287 	 *
288 	 * Status: OPTIONAL
289 	 */
290 	void (*unlock_native_capacity)(struct scsi_device *);
291 
292 	/*
293 	 * Can be used to export driver statistics and other infos to the
294 	 * world outside the kernel ie. userspace and it also provides an
295 	 * interface to feed the driver with information.
296 	 *
297 	 * Status: OBSOLETE
298 	 */
299 	int (*show_info)(struct seq_file *, struct Scsi_Host *);
300 	int (*write_info)(struct Scsi_Host *, char *, int);
301 
302 	/*
303 	 * This is an optional routine that allows the transport to become
304 	 * involved when a scsi io timer fires. The return value tells the
305 	 * timer routine how to finish the io timeout handling.
306 	 *
307 	 * Status: OPTIONAL
308 	 */
309 	enum blk_eh_timer_return (*eh_timed_out)(struct scsi_cmnd *);
310 
311 	/* This is an optional routine that allows transport to initiate
312 	 * LLD adapter or firmware reset using sysfs attribute.
313 	 *
314 	 * Return values: 0 on success, -ve value on failure.
315 	 *
316 	 * Status: OPTIONAL
317 	 */
318 
319 	int (*host_reset)(struct Scsi_Host *shost, int reset_type);
320 #define SCSI_ADAPTER_RESET	1
321 #define SCSI_FIRMWARE_RESET	2
322 
323 
324 	/*
325 	 * Name of proc directory
326 	 */
327 	const char *proc_name;
328 
329 	/*
330 	 * Used to store the procfs directory if a driver implements the
331 	 * show_info method.
332 	 */
333 	struct proc_dir_entry *proc_dir;
334 
335 	/*
336 	 * This determines if we will use a non-interrupt driven
337 	 * or an interrupt driven scheme.  It is set to the maximum number
338 	 * of simultaneous commands a single hw queue in HBA will accept.
339 	 */
340 	int can_queue;
341 
342 	/*
343 	 * In many instances, especially where disconnect / reconnect are
344 	 * supported, our host also has an ID on the SCSI bus.  If this is
345 	 * the case, then it must be reserved.  Please set this_id to -1 if
346 	 * your setup is in single initiator mode, and the host lacks an
347 	 * ID.
348 	 */
349 	int this_id;
350 
351 	/*
352 	 * This determines the degree to which the host adapter is capable
353 	 * of scatter-gather.
354 	 */
355 	unsigned short sg_tablesize;
356 	unsigned short sg_prot_tablesize;
357 
358 	/*
359 	 * Set this if the host adapter has limitations beside segment count.
360 	 */
361 	unsigned int max_sectors;
362 
363 	/*
364 	 * Maximum size in bytes of a single segment.
365 	 */
366 	unsigned int max_segment_size;
367 
368 	/*
369 	 * DMA scatter gather segment boundary limit. A segment crossing this
370 	 * boundary will be split in two.
371 	 */
372 	unsigned long dma_boundary;
373 
374 	unsigned long virt_boundary_mask;
375 
376 	/*
377 	 * This specifies "machine infinity" for host templates which don't
378 	 * limit the transfer size.  Note this limit represents an absolute
379 	 * maximum, and may be over the transfer limits allowed for
380 	 * individual devices (e.g. 256 for SCSI-1).
381 	 */
382 #define SCSI_DEFAULT_MAX_SECTORS	1024
383 
384 	/*
385 	 * True if this host adapter can make good use of linked commands.
386 	 * This will allow more than one command to be queued to a given
387 	 * unit on a given host.  Set this to the maximum number of command
388 	 * blocks to be provided for each device.  Set this to 1 for one
389 	 * command block per lun, 2 for two, etc.  Do not set this to 0.
390 	 * You should make sure that the host adapter will do the right thing
391 	 * before you try setting this above 1.
392 	 */
393 	short cmd_per_lun;
394 
395 	/*
396 	 * present contains counter indicating how many boards of this
397 	 * type were found when we did the scan.
398 	 */
399 	unsigned char present;
400 
401 	/* If use block layer to manage tags, this is tag allocation policy */
402 	int tag_alloc_policy;
403 
404 	/*
405 	 * Track QUEUE_FULL events and reduce queue depth on demand.
406 	 */
407 	unsigned track_queue_depth:1;
408 
409 	/*
410 	 * This specifies the mode that a LLD supports.
411 	 */
412 	unsigned supported_mode:2;
413 
414 	/*
415 	 * True if this host adapter uses unchecked DMA onto an ISA bus.
416 	 */
417 	unsigned unchecked_isa_dma:1;
418 
419 	/*
420 	 * True for emulated SCSI host adapters (e.g. ATAPI).
421 	 */
422 	unsigned emulated:1;
423 
424 	/*
425 	 * True if the low-level driver performs its own reset-settle delays.
426 	 */
427 	unsigned skip_settle_delay:1;
428 
429 	/* True if the controller does not support WRITE SAME */
430 	unsigned no_write_same:1;
431 
432 	/*
433 	 * Countdown for host blocking with no commands outstanding.
434 	 */
435 	unsigned int max_host_blocked;
436 
437 	/*
438 	 * Default value for the blocking.  If the queue is empty,
439 	 * host_blocked counts down in the request_fn until it restarts
440 	 * host operations as zero is reached.
441 	 *
442 	 * FIXME: This should probably be a value in the template
443 	 */
444 #define SCSI_DEFAULT_HOST_BLOCKED	7
445 
446 	/*
447 	 * Pointer to the sysfs class properties for this host, NULL terminated.
448 	 */
449 	struct device_attribute **shost_attrs;
450 
451 	/*
452 	 * Pointer to the SCSI device properties for this host, NULL terminated.
453 	 */
454 	struct device_attribute **sdev_attrs;
455 
456 	/*
457 	 * Pointer to the SCSI device attribute groups for this host,
458 	 * NULL terminated.
459 	 */
460 	const struct attribute_group **sdev_groups;
461 
462 	/*
463 	 * Vendor Identifier associated with the host
464 	 *
465 	 * Note: When specifying vendor_id, be sure to read the
466 	 *   Vendor Type and ID formatting requirements specified in
467 	 *   scsi_netlink.h
468 	 */
469 	u64 vendor_id;
470 
471 	/*
472 	 * Additional per-command data allocated for the driver.
473 	 */
474 	unsigned int cmd_size;
475 	struct scsi_host_cmd_pool *cmd_pool;
476 
477 	/* Delay for runtime autosuspend */
478 	int rpm_autosuspend_delay;
479 };
480 
481 /*
482  * Temporary #define for host lock push down. Can be removed when all
483  * drivers have been updated to take advantage of unlocked
484  * queuecommand.
485  *
486  */
487 #define DEF_SCSI_QCMD(func_name) \
488 	int func_name(struct Scsi_Host *shost, struct scsi_cmnd *cmd)	\
489 	{								\
490 		unsigned long irq_flags;				\
491 		int rc;							\
492 		spin_lock_irqsave(shost->host_lock, irq_flags);		\
493 		rc = func_name##_lck (cmd, cmd->scsi_done);			\
494 		spin_unlock_irqrestore(shost->host_lock, irq_flags);	\
495 		return rc;						\
496 	}
497 
498 
499 /*
500  * shost state: If you alter this, you also need to alter scsi_sysfs.c
501  * (for the ascii descriptions) and the state model enforcer:
502  * scsi_host_set_state()
503  */
504 enum scsi_host_state {
505 	SHOST_CREATED = 1,
506 	SHOST_RUNNING,
507 	SHOST_CANCEL,
508 	SHOST_DEL,
509 	SHOST_RECOVERY,
510 	SHOST_CANCEL_RECOVERY,
511 	SHOST_DEL_RECOVERY,
512 };
513 
514 struct Scsi_Host {
515 	/*
516 	 * __devices is protected by the host_lock, but you should
517 	 * usually use scsi_device_lookup / shost_for_each_device
518 	 * to access it and don't care about locking yourself.
519 	 * In the rare case of being in irq context you can use
520 	 * their __ prefixed variants with the lock held. NEVER
521 	 * access this list directly from a driver.
522 	 */
523 	struct list_head	__devices;
524 	struct list_head	__targets;
525 
526 	struct list_head	starved_list;
527 
528 	spinlock_t		default_lock;
529 	spinlock_t		*host_lock;
530 
531 	struct mutex		scan_mutex;/* serialize scanning activity */
532 
533 	struct list_head	eh_cmd_q;
534 	struct task_struct    * ehandler;  /* Error recovery thread. */
535 	struct completion     * eh_action; /* Wait for specific actions on the
536 					      host. */
537 	wait_queue_head_t       host_wait;
538 	struct scsi_host_template *hostt;
539 	struct scsi_transport_template *transportt;
540 
541 	/* Area to keep a shared tag map */
542 	struct blk_mq_tag_set	tag_set;
543 
544 	atomic_t host_blocked;
545 
546 	unsigned int host_failed;	   /* commands that failed.
547 					      protected by host_lock */
548 	unsigned int host_eh_scheduled;    /* EH scheduled without command */
549 
550 	unsigned int host_no;  /* Used for IOCTL_GET_IDLUN, /proc/scsi et al. */
551 
552 	/* next two fields are used to bound the time spent in error handling */
553 	int eh_deadline;
554 	unsigned long last_reset;
555 
556 
557 	/*
558 	 * These three parameters can be used to allow for wide scsi,
559 	 * and for host adapters that support multiple busses
560 	 * The last two should be set to 1 more than the actual max id
561 	 * or lun (e.g. 8 for SCSI parallel systems).
562 	 */
563 	unsigned int max_channel;
564 	unsigned int max_id;
565 	u64 max_lun;
566 
567 	/*
568 	 * This is a unique identifier that must be assigned so that we
569 	 * have some way of identifying each detected host adapter properly
570 	 * and uniquely.  For hosts that do not support more than one card
571 	 * in the system at one time, this does not need to be set.  It is
572 	 * initialized to 0 in scsi_register.
573 	 */
574 	unsigned int unique_id;
575 
576 	/*
577 	 * The maximum length of SCSI commands that this host can accept.
578 	 * Probably 12 for most host adapters, but could be 16 for others.
579 	 * or 260 if the driver supports variable length cdbs.
580 	 * For drivers that don't set this field, a value of 12 is
581 	 * assumed.
582 	 */
583 	unsigned short max_cmd_len;
584 
585 	int this_id;
586 	int can_queue;
587 	short cmd_per_lun;
588 	short unsigned int sg_tablesize;
589 	short unsigned int sg_prot_tablesize;
590 	unsigned int max_sectors;
591 	unsigned int max_segment_size;
592 	unsigned long dma_boundary;
593 	unsigned long virt_boundary_mask;
594 	/*
595 	 * In scsi-mq mode, the number of hardware queues supported by the LLD.
596 	 *
597 	 * Note: it is assumed that each hardware queue has a queue depth of
598 	 * can_queue. In other words, the total queue depth per host
599 	 * is nr_hw_queues * can_queue.
600 	 */
601 	unsigned nr_hw_queues;
602 	unsigned active_mode:2;
603 	unsigned unchecked_isa_dma:1;
604 
605 	/*
606 	 * Host has requested that no further requests come through for the
607 	 * time being.
608 	 */
609 	unsigned host_self_blocked:1;
610 
611 	/*
612 	 * Host uses correct SCSI ordering not PC ordering. The bit is
613 	 * set for the minority of drivers whose authors actually read
614 	 * the spec ;).
615 	 */
616 	unsigned reverse_ordering:1;
617 
618 	/* Task mgmt function in progress */
619 	unsigned tmf_in_progress:1;
620 
621 	/* Asynchronous scan in progress */
622 	unsigned async_scan:1;
623 
624 	/* Don't resume host in EH */
625 	unsigned eh_noresume:1;
626 
627 	/* The controller does not support WRITE SAME */
628 	unsigned no_write_same:1;
629 
630 	/* Host responded with short (<36 bytes) INQUIRY result */
631 	unsigned short_inquiry:1;
632 
633 	/* The transport requires the LUN bits NOT to be stored in CDB[1] */
634 	unsigned no_scsi2_lun_in_cdb:1;
635 
636 	/*
637 	 * Optional work queue to be utilized by the transport
638 	 */
639 	char work_q_name[20];
640 	struct workqueue_struct *work_q;
641 
642 	/*
643 	 * Task management function work queue
644 	 */
645 	struct workqueue_struct *tmf_work_q;
646 
647 	/*
648 	 * Value host_blocked counts down from
649 	 */
650 	unsigned int max_host_blocked;
651 
652 	/* Protection Information */
653 	unsigned int prot_capabilities;
654 	unsigned char prot_guard_type;
655 
656 	/* legacy crap */
657 	unsigned long base;
658 	unsigned long io_port;
659 	unsigned char n_io_port;
660 	unsigned char dma_channel;
661 	unsigned int  irq;
662 
663 
664 	enum scsi_host_state shost_state;
665 
666 	/* ldm bits */
667 	struct device		shost_gendev, shost_dev;
668 
669 	/*
670 	 * Points to the transport data (if any) which is allocated
671 	 * separately
672 	 */
673 	void *shost_data;
674 
675 	/*
676 	 * Points to the physical bus device we'd use to do DMA
677 	 * Needed just in case we have virtual hosts.
678 	 */
679 	struct device *dma_dev;
680 
681 	/*
682 	 * We should ensure that this is aligned, both for better performance
683 	 * and also because some compilers (m68k) don't automatically force
684 	 * alignment to a long boundary.
685 	 */
686 	unsigned long hostdata[]  /* Used for storage of host specific stuff */
687 		__attribute__ ((aligned (sizeof(unsigned long))));
688 };
689 
690 #define		class_to_shost(d)	\
691 	container_of(d, struct Scsi_Host, shost_dev)
692 
693 #define shost_printk(prefix, shost, fmt, a...)	\
694 	dev_printk(prefix, &(shost)->shost_gendev, fmt, ##a)
695 
696 static inline void *shost_priv(struct Scsi_Host *shost)
697 {
698 	return (void *)shost->hostdata;
699 }
700 
701 int scsi_is_host_device(const struct device *);
702 
703 static inline struct Scsi_Host *dev_to_shost(struct device *dev)
704 {
705 	while (!scsi_is_host_device(dev)) {
706 		if (!dev->parent)
707 			return NULL;
708 		dev = dev->parent;
709 	}
710 	return container_of(dev, struct Scsi_Host, shost_gendev);
711 }
712 
713 static inline int scsi_host_in_recovery(struct Scsi_Host *shost)
714 {
715 	return shost->shost_state == SHOST_RECOVERY ||
716 		shost->shost_state == SHOST_CANCEL_RECOVERY ||
717 		shost->shost_state == SHOST_DEL_RECOVERY ||
718 		shost->tmf_in_progress;
719 }
720 
721 extern int scsi_queue_work(struct Scsi_Host *, struct work_struct *);
722 extern void scsi_flush_work(struct Scsi_Host *);
723 
724 extern struct Scsi_Host *scsi_host_alloc(struct scsi_host_template *, int);
725 extern int __must_check scsi_add_host_with_dma(struct Scsi_Host *,
726 					       struct device *,
727 					       struct device *);
728 extern void scsi_scan_host(struct Scsi_Host *);
729 extern void scsi_rescan_device(struct device *);
730 extern void scsi_remove_host(struct Scsi_Host *);
731 extern struct Scsi_Host *scsi_host_get(struct Scsi_Host *);
732 extern int scsi_host_busy(struct Scsi_Host *shost);
733 extern void scsi_host_put(struct Scsi_Host *t);
734 extern struct Scsi_Host *scsi_host_lookup(unsigned short);
735 extern const char *scsi_host_state_name(enum scsi_host_state);
736 extern void scsi_host_complete_all_commands(struct Scsi_Host *shost,
737 					    int status);
738 
739 static inline int __must_check scsi_add_host(struct Scsi_Host *host,
740 					     struct device *dev)
741 {
742 	return scsi_add_host_with_dma(host, dev, dev);
743 }
744 
745 static inline struct device *scsi_get_device(struct Scsi_Host *shost)
746 {
747         return shost->shost_gendev.parent;
748 }
749 
750 /**
751  * scsi_host_scan_allowed - Is scanning of this host allowed
752  * @shost:	Pointer to Scsi_Host.
753  **/
754 static inline int scsi_host_scan_allowed(struct Scsi_Host *shost)
755 {
756 	return shost->shost_state == SHOST_RUNNING ||
757 	       shost->shost_state == SHOST_RECOVERY;
758 }
759 
760 extern void scsi_unblock_requests(struct Scsi_Host *);
761 extern void scsi_block_requests(struct Scsi_Host *);
762 extern int scsi_host_block(struct Scsi_Host *shost);
763 extern int scsi_host_unblock(struct Scsi_Host *shost, int new_state);
764 
765 void scsi_host_busy_iter(struct Scsi_Host *,
766 			 bool (*fn)(struct scsi_cmnd *, void *, bool), void *priv);
767 
768 struct class_container;
769 
770 /*
771  * These two functions are used to allocate and free a pseudo device
772  * which will connect to the host adapter itself rather than any
773  * physical device.  You must deallocate when you are done with the
774  * thing.  This physical pseudo-device isn't real and won't be available
775  * from any high-level drivers.
776  */
777 extern void scsi_free_host_dev(struct scsi_device *);
778 extern struct scsi_device *scsi_get_host_dev(struct Scsi_Host *);
779 
780 /*
781  * DIF defines the exchange of protection information between
782  * initiator and SBC block device.
783  *
784  * DIX defines the exchange of protection information between OS and
785  * initiator.
786  */
787 enum scsi_host_prot_capabilities {
788 	SHOST_DIF_TYPE1_PROTECTION = 1 << 0, /* T10 DIF Type 1 */
789 	SHOST_DIF_TYPE2_PROTECTION = 1 << 1, /* T10 DIF Type 2 */
790 	SHOST_DIF_TYPE3_PROTECTION = 1 << 2, /* T10 DIF Type 3 */
791 
792 	SHOST_DIX_TYPE0_PROTECTION = 1 << 3, /* DIX between OS and HBA only */
793 	SHOST_DIX_TYPE1_PROTECTION = 1 << 4, /* DIX with DIF Type 1 */
794 	SHOST_DIX_TYPE2_PROTECTION = 1 << 5, /* DIX with DIF Type 2 */
795 	SHOST_DIX_TYPE3_PROTECTION = 1 << 6, /* DIX with DIF Type 3 */
796 };
797 
798 /*
799  * SCSI hosts which support the Data Integrity Extensions must
800  * indicate their capabilities by setting the prot_capabilities using
801  * this call.
802  */
803 static inline void scsi_host_set_prot(struct Scsi_Host *shost, unsigned int mask)
804 {
805 	shost->prot_capabilities = mask;
806 }
807 
808 static inline unsigned int scsi_host_get_prot(struct Scsi_Host *shost)
809 {
810 	return shost->prot_capabilities;
811 }
812 
813 static inline int scsi_host_prot_dma(struct Scsi_Host *shost)
814 {
815 	return shost->prot_capabilities >= SHOST_DIX_TYPE0_PROTECTION;
816 }
817 
818 static inline unsigned int scsi_host_dif_capable(struct Scsi_Host *shost, unsigned int target_type)
819 {
820 	static unsigned char cap[] = { 0,
821 				       SHOST_DIF_TYPE1_PROTECTION,
822 				       SHOST_DIF_TYPE2_PROTECTION,
823 				       SHOST_DIF_TYPE3_PROTECTION };
824 
825 	if (target_type >= ARRAY_SIZE(cap))
826 		return 0;
827 
828 	return shost->prot_capabilities & cap[target_type] ? target_type : 0;
829 }
830 
831 static inline unsigned int scsi_host_dix_capable(struct Scsi_Host *shost, unsigned int target_type)
832 {
833 #if defined(CONFIG_BLK_DEV_INTEGRITY)
834 	static unsigned char cap[] = { SHOST_DIX_TYPE0_PROTECTION,
835 				       SHOST_DIX_TYPE1_PROTECTION,
836 				       SHOST_DIX_TYPE2_PROTECTION,
837 				       SHOST_DIX_TYPE3_PROTECTION };
838 
839 	if (target_type >= ARRAY_SIZE(cap))
840 		return 0;
841 
842 	return shost->prot_capabilities & cap[target_type];
843 #endif
844 	return 0;
845 }
846 
847 /*
848  * All DIX-capable initiators must support the T10-mandated CRC
849  * checksum.  Controllers can optionally implement the IP checksum
850  * scheme which has much lower impact on system performance.  Note
851  * that the main rationale for the checksum is to match integrity
852  * metadata with data.  Detecting bit errors are a job for ECC memory
853  * and buses.
854  */
855 
856 enum scsi_host_guard_type {
857 	SHOST_DIX_GUARD_CRC = 1 << 0,
858 	SHOST_DIX_GUARD_IP  = 1 << 1,
859 };
860 
861 static inline void scsi_host_set_guard(struct Scsi_Host *shost, unsigned char type)
862 {
863 	shost->prot_guard_type = type;
864 }
865 
866 static inline unsigned char scsi_host_get_guard(struct Scsi_Host *shost)
867 {
868 	return shost->prot_guard_type;
869 }
870 
871 extern int scsi_host_set_state(struct Scsi_Host *, enum scsi_host_state);
872 
873 #endif /* _SCSI_SCSI_HOST_H */
874