1 #ifndef _SCSI_SCSI_HOST_H
2 #define _SCSI_SCSI_HOST_H
3 
4 #include <linux/device.h>
5 #include <linux/list.h>
6 #include <linux/types.h>
7 #include <linux/workqueue.h>
8 #include <linux/mutex.h>
9 #include <scsi/scsi.h>
10 
11 struct request_queue;
12 struct block_device;
13 struct completion;
14 struct module;
15 struct scsi_cmnd;
16 struct scsi_device;
17 struct scsi_target;
18 struct Scsi_Host;
19 struct scsi_host_cmd_pool;
20 struct scsi_transport_template;
21 struct blk_queue_tags;
22 
23 
24 /*
25  * The various choices mean:
26  * NONE: Self evident.	Host adapter is not capable of scatter-gather.
27  * ALL:	 Means that the host adapter module can do scatter-gather,
28  *	 and that there is no limit to the size of the table to which
29  *	 we scatter/gather data.  The value we set here is the maximum
30  *	 single element sglist.  To use chained sglists, the adapter
31  *	 has to set a value beyond ALL (and correctly use the chain
32  *	 handling API.
33  * Anything else:  Indicates the maximum number of chains that can be
34  *	 used in one scatter-gather request.
35  */
36 #define SG_NONE 0
37 #define SG_ALL	SCSI_MAX_SG_SEGMENTS
38 
39 #define MODE_UNKNOWN 0x00
40 #define MODE_INITIATOR 0x01
41 #define MODE_TARGET 0x02
42 
43 #define DISABLE_CLUSTERING 0
44 #define ENABLE_CLUSTERING 1
45 
46 enum {
47 	SCSI_QDEPTH_DEFAULT,	/* default requested change, e.g. from sysfs */
48 	SCSI_QDEPTH_QFULL,	/* scsi-ml requested due to queue full */
49 	SCSI_QDEPTH_RAMP_UP,	/* scsi-ml requested due to threshold event */
50 };
51 
52 struct scsi_host_template {
53 	struct module *module;
54 	const char *name;
55 
56 	/*
57 	 * Used to initialize old-style drivers.  For new-style drivers
58 	 * just perform all work in your module initialization function.
59 	 *
60 	 * Status:  OBSOLETE
61 	 */
62 	int (* detect)(struct scsi_host_template *);
63 
64 	/*
65 	 * Used as unload callback for hosts with old-style drivers.
66 	 *
67 	 * Status: OBSOLETE
68 	 */
69 	int (* release)(struct Scsi_Host *);
70 
71 	/*
72 	 * The info function will return whatever useful information the
73 	 * developer sees fit.  If not provided, then the name field will
74 	 * be used instead.
75 	 *
76 	 * Status: OPTIONAL
77 	 */
78 	const char *(* info)(struct Scsi_Host *);
79 
80 	/*
81 	 * Ioctl interface
82 	 *
83 	 * Status: OPTIONAL
84 	 */
85 	int (* ioctl)(struct scsi_device *dev, int cmd, void __user *arg);
86 
87 
88 #ifdef CONFIG_COMPAT
89 	/*
90 	 * Compat handler. Handle 32bit ABI.
91 	 * When unknown ioctl is passed return -ENOIOCTLCMD.
92 	 *
93 	 * Status: OPTIONAL
94 	 */
95 	int (* compat_ioctl)(struct scsi_device *dev, int cmd, void __user *arg);
96 #endif
97 
98 	/*
99 	 * The queuecommand function is used to queue up a scsi
100 	 * command block to the LLDD.  When the driver finished
101 	 * processing the command the done callback is invoked.
102 	 *
103 	 * If queuecommand returns 0, then the HBA has accepted the
104 	 * command.  The done() function must be called on the command
105 	 * when the driver has finished with it. (you may call done on the
106 	 * command before queuecommand returns, but in this case you
107 	 * *must* return 0 from queuecommand).
108 	 *
109 	 * Queuecommand may also reject the command, in which case it may
110 	 * not touch the command and must not call done() for it.
111 	 *
112 	 * There are two possible rejection returns:
113 	 *
114 	 *   SCSI_MLQUEUE_DEVICE_BUSY: Block this device temporarily, but
115 	 *   allow commands to other devices serviced by this host.
116 	 *
117 	 *   SCSI_MLQUEUE_HOST_BUSY: Block all devices served by this
118 	 *   host temporarily.
119 	 *
120          * For compatibility, any other non-zero return is treated the
121          * same as SCSI_MLQUEUE_HOST_BUSY.
122 	 *
123 	 * NOTE: "temporarily" means either until the next command for#
124 	 * this device/host completes, or a period of time determined by
125 	 * I/O pressure in the system if there are no other outstanding
126 	 * commands.
127 	 *
128 	 * STATUS: REQUIRED
129 	 */
130 	int (* queuecommand)(struct Scsi_Host *, struct scsi_cmnd *);
131 
132 	/*
133 	 * The transfer functions are used to queue a scsi command to
134 	 * the LLD. When the driver is finished processing the command
135 	 * the done callback is invoked.
136 	 *
137 	 * This is called to inform the LLD to transfer
138 	 * scsi_bufflen(cmd) bytes. scsi_sg_count(cmd) speciefies the
139 	 * number of scatterlist entried in the command and
140 	 * scsi_sglist(cmd) returns the scatterlist.
141 	 *
142 	 * return values: see queuecommand
143 	 *
144 	 * If the LLD accepts the cmd, it should set the result to an
145 	 * appropriate value when completed before calling the done function.
146 	 *
147 	 * STATUS: REQUIRED FOR TARGET DRIVERS
148 	 */
149 	/* TODO: rename */
150 	int (* transfer_response)(struct scsi_cmnd *,
151 				  void (*done)(struct scsi_cmnd *));
152 
153 	/*
154 	 * This is an error handling strategy routine.  You don't need to
155 	 * define one of these if you don't want to - there is a default
156 	 * routine that is present that should work in most cases.  For those
157 	 * driver authors that have the inclination and ability to write their
158 	 * own strategy routine, this is where it is specified.  Note - the
159 	 * strategy routine is *ALWAYS* run in the context of the kernel eh
160 	 * thread.  Thus you are guaranteed to *NOT* be in an interrupt
161 	 * handler when you execute this, and you are also guaranteed to
162 	 * *NOT* have any other commands being queued while you are in the
163 	 * strategy routine. When you return from this function, operations
164 	 * return to normal.
165 	 *
166 	 * See scsi_error.c scsi_unjam_host for additional comments about
167 	 * what this function should and should not be attempting to do.
168 	 *
169 	 * Status: REQUIRED	(at least one of them)
170 	 */
171 	int (* eh_abort_handler)(struct scsi_cmnd *);
172 	int (* eh_device_reset_handler)(struct scsi_cmnd *);
173 	int (* eh_target_reset_handler)(struct scsi_cmnd *);
174 	int (* eh_bus_reset_handler)(struct scsi_cmnd *);
175 	int (* eh_host_reset_handler)(struct scsi_cmnd *);
176 
177 	/*
178 	 * Before the mid layer attempts to scan for a new device where none
179 	 * currently exists, it will call this entry in your driver.  Should
180 	 * your driver need to allocate any structs or perform any other init
181 	 * items in order to send commands to a currently unused target/lun
182 	 * combo, then this is where you can perform those allocations.  This
183 	 * is specifically so that drivers won't have to perform any kind of
184 	 * "is this a new device" checks in their queuecommand routine,
185 	 * thereby making the hot path a bit quicker.
186 	 *
187 	 * Return values: 0 on success, non-0 on failure
188 	 *
189 	 * Deallocation:  If we didn't find any devices at this ID, you will
190 	 * get an immediate call to slave_destroy().  If we find something
191 	 * here then you will get a call to slave_configure(), then the
192 	 * device will be used for however long it is kept around, then when
193 	 * the device is removed from the system (or * possibly at reboot
194 	 * time), you will then get a call to slave_destroy().  This is
195 	 * assuming you implement slave_configure and slave_destroy.
196 	 * However, if you allocate memory and hang it off the device struct,
197 	 * then you must implement the slave_destroy() routine at a minimum
198 	 * in order to avoid leaking memory
199 	 * each time a device is tore down.
200 	 *
201 	 * Status: OPTIONAL
202 	 */
203 	int (* slave_alloc)(struct scsi_device *);
204 
205 	/*
206 	 * Once the device has responded to an INQUIRY and we know the
207 	 * device is online, we call into the low level driver with the
208 	 * struct scsi_device *.  If the low level device driver implements
209 	 * this function, it *must* perform the task of setting the queue
210 	 * depth on the device.  All other tasks are optional and depend
211 	 * on what the driver supports and various implementation details.
212 	 *
213 	 * Things currently recommended to be handled at this time include:
214 	 *
215 	 * 1.  Setting the device queue depth.  Proper setting of this is
216 	 *     described in the comments for scsi_adjust_queue_depth.
217 	 * 2.  Determining if the device supports the various synchronous
218 	 *     negotiation protocols.  The device struct will already have
219 	 *     responded to INQUIRY and the results of the standard items
220 	 *     will have been shoved into the various device flag bits, eg.
221 	 *     device->sdtr will be true if the device supports SDTR messages.
222 	 * 3.  Allocating command structs that the device will need.
223 	 * 4.  Setting the default timeout on this device (if needed).
224 	 * 5.  Anything else the low level driver might want to do on a device
225 	 *     specific setup basis...
226 	 * 6.  Return 0 on success, non-0 on error.  The device will be marked
227 	 *     as offline on error so that no access will occur.  If you return
228 	 *     non-0, your slave_destroy routine will never get called for this
229 	 *     device, so don't leave any loose memory hanging around, clean
230 	 *     up after yourself before returning non-0
231 	 *
232 	 * Status: OPTIONAL
233 	 */
234 	int (* slave_configure)(struct scsi_device *);
235 
236 	/*
237 	 * Immediately prior to deallocating the device and after all activity
238 	 * has ceased the mid layer calls this point so that the low level
239 	 * driver may completely detach itself from the scsi device and vice
240 	 * versa.  The low level driver is responsible for freeing any memory
241 	 * it allocated in the slave_alloc or slave_configure calls.
242 	 *
243 	 * Status: OPTIONAL
244 	 */
245 	void (* slave_destroy)(struct scsi_device *);
246 
247 	/*
248 	 * Before the mid layer attempts to scan for a new device attached
249 	 * to a target where no target currently exists, it will call this
250 	 * entry in your driver.  Should your driver need to allocate any
251 	 * structs or perform any other init items in order to send commands
252 	 * to a currently unused target, then this is where you can perform
253 	 * those allocations.
254 	 *
255 	 * Return values: 0 on success, non-0 on failure
256 	 *
257 	 * Status: OPTIONAL
258 	 */
259 	int (* target_alloc)(struct scsi_target *);
260 
261 	/*
262 	 * Immediately prior to deallocating the target structure, and
263 	 * after all activity to attached scsi devices has ceased, the
264 	 * midlayer calls this point so that the driver may deallocate
265 	 * and terminate any references to the target.
266 	 *
267 	 * Status: OPTIONAL
268 	 */
269 	void (* target_destroy)(struct scsi_target *);
270 
271 	/*
272 	 * If a host has the ability to discover targets on its own instead
273 	 * of scanning the entire bus, it can fill in this function and
274 	 * call scsi_scan_host().  This function will be called periodically
275 	 * until it returns 1 with the scsi_host and the elapsed time of
276 	 * the scan in jiffies.
277 	 *
278 	 * Status: OPTIONAL
279 	 */
280 	int (* scan_finished)(struct Scsi_Host *, unsigned long);
281 
282 	/*
283 	 * If the host wants to be called before the scan starts, but
284 	 * after the midlayer has set up ready for the scan, it can fill
285 	 * in this function.
286 	 *
287 	 * Status: OPTIONAL
288 	 */
289 	void (* scan_start)(struct Scsi_Host *);
290 
291 	/*
292 	 * Fill in this function to allow the queue depth of this host
293 	 * to be changeable (on a per device basis).  Returns either
294 	 * the current queue depth setting (may be different from what
295 	 * was passed in) or an error.  An error should only be
296 	 * returned if the requested depth is legal but the driver was
297 	 * unable to set it.  If the requested depth is illegal, the
298 	 * driver should set and return the closest legal queue depth.
299 	 *
300 	 * Status: OPTIONAL
301 	 */
302 	int (* change_queue_depth)(struct scsi_device *, int, int);
303 
304 	/*
305 	 * Fill in this function to allow the changing of tag types
306 	 * (this also allows the enabling/disabling of tag command
307 	 * queueing).  An error should only be returned if something
308 	 * went wrong in the driver while trying to set the tag type.
309 	 * If the driver doesn't support the requested tag type, then
310 	 * it should set the closest type it does support without
311 	 * returning an error.  Returns the actual tag type set.
312 	 *
313 	 * Status: OPTIONAL
314 	 */
315 	int (* change_queue_type)(struct scsi_device *, int);
316 
317 	/*
318 	 * This function determines the BIOS parameters for a given
319 	 * harddisk.  These tend to be numbers that are made up by
320 	 * the host adapter.  Parameters:
321 	 * size, device, list (heads, sectors, cylinders)
322 	 *
323 	 * Status: OPTIONAL
324 	 */
325 	int (* bios_param)(struct scsi_device *, struct block_device *,
326 			sector_t, int []);
327 
328 	/*
329 	 * This function is called when one or more partitions on the
330 	 * device reach beyond the end of the device.
331 	 *
332 	 * Status: OPTIONAL
333 	 */
334 	void (*unlock_native_capacity)(struct scsi_device *);
335 
336 	/*
337 	 * Can be used to export driver statistics and other infos to the
338 	 * world outside the kernel ie. userspace and it also provides an
339 	 * interface to feed the driver with information.
340 	 *
341 	 * Status: OBSOLETE
342 	 */
343 	int (*proc_info)(struct Scsi_Host *, char *, char **, off_t, int, int);
344 
345 	/*
346 	 * This is an optional routine that allows the transport to become
347 	 * involved when a scsi io timer fires. The return value tells the
348 	 * timer routine how to finish the io timeout handling:
349 	 * EH_HANDLED:		I fixed the error, please complete the command
350 	 * EH_RESET_TIMER:	I need more time, reset the timer and
351 	 *			begin counting again
352 	 * EH_NOT_HANDLED	Begin normal error recovery
353 	 *
354 	 * Status: OPTIONAL
355 	 */
356 	enum blk_eh_timer_return (*eh_timed_out)(struct scsi_cmnd *);
357 
358 	/* This is an optional routine that allows transport to initiate
359 	 * LLD adapter or firmware reset using sysfs attribute.
360 	 *
361 	 * Return values: 0 on success, -ve value on failure.
362 	 *
363 	 * Status: OPTIONAL
364 	 */
365 
366 	int (*host_reset)(struct Scsi_Host *shost, int reset_type);
367 #define SCSI_ADAPTER_RESET	1
368 #define SCSI_FIRMWARE_RESET	2
369 
370 
371 	/*
372 	 * Name of proc directory
373 	 */
374 	const char *proc_name;
375 
376 	/*
377 	 * Used to store the procfs directory if a driver implements the
378 	 * proc_info method.
379 	 */
380 	struct proc_dir_entry *proc_dir;
381 
382 	/*
383 	 * This determines if we will use a non-interrupt driven
384 	 * or an interrupt driven scheme.  It is set to the maximum number
385 	 * of simultaneous commands a given host adapter will accept.
386 	 */
387 	int can_queue;
388 
389 	/*
390 	 * In many instances, especially where disconnect / reconnect are
391 	 * supported, our host also has an ID on the SCSI bus.  If this is
392 	 * the case, then it must be reserved.  Please set this_id to -1 if
393 	 * your setup is in single initiator mode, and the host lacks an
394 	 * ID.
395 	 */
396 	int this_id;
397 
398 	/*
399 	 * This determines the degree to which the host adapter is capable
400 	 * of scatter-gather.
401 	 */
402 	unsigned short sg_tablesize;
403 	unsigned short sg_prot_tablesize;
404 
405 	/*
406 	 * Set this if the host adapter has limitations beside segment count.
407 	 */
408 	unsigned short max_sectors;
409 
410 	/*
411 	 * DMA scatter gather segment boundary limit. A segment crossing this
412 	 * boundary will be split in two.
413 	 */
414 	unsigned long dma_boundary;
415 
416 	/*
417 	 * This specifies "machine infinity" for host templates which don't
418 	 * limit the transfer size.  Note this limit represents an absolute
419 	 * maximum, and may be over the transfer limits allowed for
420 	 * individual devices (e.g. 256 for SCSI-1).
421 	 */
422 #define SCSI_DEFAULT_MAX_SECTORS	1024
423 
424 	/*
425 	 * True if this host adapter can make good use of linked commands.
426 	 * This will allow more than one command to be queued to a given
427 	 * unit on a given host.  Set this to the maximum number of command
428 	 * blocks to be provided for each device.  Set this to 1 for one
429 	 * command block per lun, 2 for two, etc.  Do not set this to 0.
430 	 * You should make sure that the host adapter will do the right thing
431 	 * before you try setting this above 1.
432 	 */
433 	short cmd_per_lun;
434 
435 	/*
436 	 * present contains counter indicating how many boards of this
437 	 * type were found when we did the scan.
438 	 */
439 	unsigned char present;
440 
441 	/*
442 	 * This specifies the mode that a LLD supports.
443 	 */
444 	unsigned supported_mode:2;
445 
446 	/*
447 	 * True if this host adapter uses unchecked DMA onto an ISA bus.
448 	 */
449 	unsigned unchecked_isa_dma:1;
450 
451 	/*
452 	 * True if this host adapter can make good use of clustering.
453 	 * I originally thought that if the tablesize was large that it
454 	 * was a waste of CPU cycles to prepare a cluster list, but
455 	 * it works out that the Buslogic is faster if you use a smaller
456 	 * number of segments (i.e. use clustering).  I guess it is
457 	 * inefficient.
458 	 */
459 	unsigned use_clustering:1;
460 
461 	/*
462 	 * True for emulated SCSI host adapters (e.g. ATAPI).
463 	 */
464 	unsigned emulated:1;
465 
466 	/*
467 	 * True if the low-level driver performs its own reset-settle delays.
468 	 */
469 	unsigned skip_settle_delay:1;
470 
471 	/*
472 	 * True if we are using ordered write support.
473 	 */
474 	unsigned ordered_tag:1;
475 
476 	/*
477 	 * Countdown for host blocking with no commands outstanding.
478 	 */
479 	unsigned int max_host_blocked;
480 
481 	/*
482 	 * Default value for the blocking.  If the queue is empty,
483 	 * host_blocked counts down in the request_fn until it restarts
484 	 * host operations as zero is reached.
485 	 *
486 	 * FIXME: This should probably be a value in the template
487 	 */
488 #define SCSI_DEFAULT_HOST_BLOCKED	7
489 
490 	/*
491 	 * Pointer to the sysfs class properties for this host, NULL terminated.
492 	 */
493 	struct device_attribute **shost_attrs;
494 
495 	/*
496 	 * Pointer to the SCSI device properties for this host, NULL terminated.
497 	 */
498 	struct device_attribute **sdev_attrs;
499 
500 	/*
501 	 * List of hosts per template.
502 	 *
503 	 * This is only for use by scsi_module.c for legacy templates.
504 	 * For these access to it is synchronized implicitly by
505 	 * module_init/module_exit.
506 	 */
507 	struct list_head legacy_hosts;
508 
509 	/*
510 	 * Vendor Identifier associated with the host
511 	 *
512 	 * Note: When specifying vendor_id, be sure to read the
513 	 *   Vendor Type and ID formatting requirements specified in
514 	 *   scsi_netlink.h
515 	 */
516 	u64 vendor_id;
517 };
518 
519 /*
520  * Temporary #define for host lock push down. Can be removed when all
521  * drivers have been updated to take advantage of unlocked
522  * queuecommand.
523  *
524  */
525 #define DEF_SCSI_QCMD(func_name) \
526 	int func_name(struct Scsi_Host *shost, struct scsi_cmnd *cmd)	\
527 	{								\
528 		unsigned long irq_flags;				\
529 		int rc;							\
530 		spin_lock_irqsave(shost->host_lock, irq_flags);		\
531 		scsi_cmd_get_serial(shost, cmd);			\
532 		rc = func_name##_lck (cmd, cmd->scsi_done);			\
533 		spin_unlock_irqrestore(shost->host_lock, irq_flags);	\
534 		return rc;						\
535 	}
536 
537 
538 /*
539  * shost state: If you alter this, you also need to alter scsi_sysfs.c
540  * (for the ascii descriptions) and the state model enforcer:
541  * scsi_host_set_state()
542  */
543 enum scsi_host_state {
544 	SHOST_CREATED = 1,
545 	SHOST_RUNNING,
546 	SHOST_CANCEL,
547 	SHOST_DEL,
548 	SHOST_RECOVERY,
549 	SHOST_CANCEL_RECOVERY,
550 	SHOST_DEL_RECOVERY,
551 };
552 
553 struct Scsi_Host {
554 	/*
555 	 * __devices is protected by the host_lock, but you should
556 	 * usually use scsi_device_lookup / shost_for_each_device
557 	 * to access it and don't care about locking yourself.
558 	 * In the rare case of beeing in irq context you can use
559 	 * their __ prefixed variants with the lock held. NEVER
560 	 * access this list directly from a driver.
561 	 */
562 	struct list_head	__devices;
563 	struct list_head	__targets;
564 
565 	struct scsi_host_cmd_pool *cmd_pool;
566 	spinlock_t		free_list_lock;
567 	struct list_head	free_list; /* backup store of cmd structs */
568 	struct list_head	starved_list;
569 
570 	spinlock_t		default_lock;
571 	spinlock_t		*host_lock;
572 
573 	struct mutex		scan_mutex;/* serialize scanning activity */
574 
575 	struct list_head	eh_cmd_q;
576 	struct task_struct    * ehandler;  /* Error recovery thread. */
577 	struct completion     * eh_action; /* Wait for specific actions on the
578 					      host. */
579 	wait_queue_head_t       host_wait;
580 	struct scsi_host_template *hostt;
581 	struct scsi_transport_template *transportt;
582 
583 	/*
584 	 * Area to keep a shared tag map (if needed, will be
585 	 * NULL if not).
586 	 */
587 	struct blk_queue_tag	*bqt;
588 
589 	/*
590 	 * The following two fields are protected with host_lock;
591 	 * however, eh routines can safely access during eh processing
592 	 * without acquiring the lock.
593 	 */
594 	unsigned int host_busy;		   /* commands actually active on low-level */
595 	unsigned int host_failed;	   /* commands that failed. */
596 	unsigned int host_eh_scheduled;    /* EH scheduled without command */
597 
598 	unsigned int host_no;  /* Used for IOCTL_GET_IDLUN, /proc/scsi et al. */
599 	int resetting; /* if set, it means that last_reset is a valid value */
600 	unsigned long last_reset;
601 
602 	/*
603 	 * These three parameters can be used to allow for wide scsi,
604 	 * and for host adapters that support multiple busses
605 	 * The first two should be set to 1 more than the actual max id
606 	 * or lun (i.e. 8 for normal systems).
607 	 */
608 	unsigned int max_id;
609 	unsigned int max_lun;
610 	unsigned int max_channel;
611 
612 	/*
613 	 * This is a unique identifier that must be assigned so that we
614 	 * have some way of identifying each detected host adapter properly
615 	 * and uniquely.  For hosts that do not support more than one card
616 	 * in the system at one time, this does not need to be set.  It is
617 	 * initialized to 0 in scsi_register.
618 	 */
619 	unsigned int unique_id;
620 
621 	/*
622 	 * The maximum length of SCSI commands that this host can accept.
623 	 * Probably 12 for most host adapters, but could be 16 for others.
624 	 * or 260 if the driver supports variable length cdbs.
625 	 * For drivers that don't set this field, a value of 12 is
626 	 * assumed.
627 	 */
628 	unsigned short max_cmd_len;
629 
630 	int this_id;
631 	int can_queue;
632 	short cmd_per_lun;
633 	short unsigned int sg_tablesize;
634 	short unsigned int sg_prot_tablesize;
635 	short unsigned int max_sectors;
636 	unsigned long dma_boundary;
637 	/*
638 	 * Used to assign serial numbers to the cmds.
639 	 * Protected by the host lock.
640 	 */
641 	unsigned long cmd_serial_number;
642 
643 	unsigned active_mode:2;
644 	unsigned unchecked_isa_dma:1;
645 	unsigned use_clustering:1;
646 	unsigned use_blk_tcq:1;
647 
648 	/*
649 	 * Host has requested that no further requests come through for the
650 	 * time being.
651 	 */
652 	unsigned host_self_blocked:1;
653 
654 	/*
655 	 * Host uses correct SCSI ordering not PC ordering. The bit is
656 	 * set for the minority of drivers whose authors actually read
657 	 * the spec ;).
658 	 */
659 	unsigned reverse_ordering:1;
660 
661 	/*
662 	 * Ordered write support
663 	 */
664 	unsigned ordered_tag:1;
665 
666 	/* Task mgmt function in progress */
667 	unsigned tmf_in_progress:1;
668 
669 	/* Asynchronous scan in progress */
670 	unsigned async_scan:1;
671 
672 	/* Don't resume host in EH */
673 	unsigned eh_noresume:1;
674 
675 	/*
676 	 * Optional work queue to be utilized by the transport
677 	 */
678 	char work_q_name[20];
679 	struct workqueue_struct *work_q;
680 
681 	/*
682 	 * Host has rejected a command because it was busy.
683 	 */
684 	unsigned int host_blocked;
685 
686 	/*
687 	 * Value host_blocked counts down from
688 	 */
689 	unsigned int max_host_blocked;
690 
691 	/* Protection Information */
692 	unsigned int prot_capabilities;
693 	unsigned char prot_guard_type;
694 
695 	/*
696 	 * q used for scsi_tgt msgs, async events or any other requests that
697 	 * need to be processed in userspace
698 	 */
699 	struct request_queue *uspace_req_q;
700 
701 	/* legacy crap */
702 	unsigned long base;
703 	unsigned long io_port;
704 	unsigned char n_io_port;
705 	unsigned char dma_channel;
706 	unsigned int  irq;
707 
708 
709 	enum scsi_host_state shost_state;
710 
711 	/* ldm bits */
712 	struct device		shost_gendev, shost_dev;
713 
714 	/*
715 	 * List of hosts per template.
716 	 *
717 	 * This is only for use by scsi_module.c for legacy templates.
718 	 * For these access to it is synchronized implicitly by
719 	 * module_init/module_exit.
720 	 */
721 	struct list_head sht_legacy_list;
722 
723 	/*
724 	 * Points to the transport data (if any) which is allocated
725 	 * separately
726 	 */
727 	void *shost_data;
728 
729 	/*
730 	 * Points to the physical bus device we'd use to do DMA
731 	 * Needed just in case we have virtual hosts.
732 	 */
733 	struct device *dma_dev;
734 
735 	/*
736 	 * We should ensure that this is aligned, both for better performance
737 	 * and also because some compilers (m68k) don't automatically force
738 	 * alignment to a long boundary.
739 	 */
740 	unsigned long hostdata[0]  /* Used for storage of host specific stuff */
741 		__attribute__ ((aligned (sizeof(unsigned long))));
742 };
743 
744 #define		class_to_shost(d)	\
745 	container_of(d, struct Scsi_Host, shost_dev)
746 
747 #define shost_printk(prefix, shost, fmt, a...)	\
748 	dev_printk(prefix, &(shost)->shost_gendev, fmt, ##a)
749 
shost_priv(struct Scsi_Host * shost)750 static inline void *shost_priv(struct Scsi_Host *shost)
751 {
752 	return (void *)shost->hostdata;
753 }
754 
755 int scsi_is_host_device(const struct device *);
756 
dev_to_shost(struct device * dev)757 static inline struct Scsi_Host *dev_to_shost(struct device *dev)
758 {
759 	while (!scsi_is_host_device(dev)) {
760 		if (!dev->parent)
761 			return NULL;
762 		dev = dev->parent;
763 	}
764 	return container_of(dev, struct Scsi_Host, shost_gendev);
765 }
766 
scsi_host_in_recovery(struct Scsi_Host * shost)767 static inline int scsi_host_in_recovery(struct Scsi_Host *shost)
768 {
769 	return shost->shost_state == SHOST_RECOVERY ||
770 		shost->shost_state == SHOST_CANCEL_RECOVERY ||
771 		shost->shost_state == SHOST_DEL_RECOVERY ||
772 		shost->tmf_in_progress;
773 }
774 
775 extern int scsi_queue_work(struct Scsi_Host *, struct work_struct *);
776 extern void scsi_flush_work(struct Scsi_Host *);
777 
778 extern struct Scsi_Host *scsi_host_alloc(struct scsi_host_template *, int);
779 extern int __must_check scsi_add_host_with_dma(struct Scsi_Host *,
780 					       struct device *,
781 					       struct device *);
782 extern void scsi_scan_host(struct Scsi_Host *);
783 extern void scsi_rescan_device(struct device *);
784 extern void scsi_remove_host(struct Scsi_Host *);
785 extern struct Scsi_Host *scsi_host_get(struct Scsi_Host *);
786 extern void scsi_host_put(struct Scsi_Host *t);
787 extern struct Scsi_Host *scsi_host_lookup(unsigned short);
788 extern const char *scsi_host_state_name(enum scsi_host_state);
789 extern void scsi_cmd_get_serial(struct Scsi_Host *, struct scsi_cmnd *);
790 
791 extern u64 scsi_calculate_bounce_limit(struct Scsi_Host *);
792 
scsi_add_host(struct Scsi_Host * host,struct device * dev)793 static inline int __must_check scsi_add_host(struct Scsi_Host *host,
794 					     struct device *dev)
795 {
796 	return scsi_add_host_with_dma(host, dev, dev);
797 }
798 
scsi_get_device(struct Scsi_Host * shost)799 static inline struct device *scsi_get_device(struct Scsi_Host *shost)
800 {
801         return shost->shost_gendev.parent;
802 }
803 
804 /**
805  * scsi_host_scan_allowed - Is scanning of this host allowed
806  * @shost:	Pointer to Scsi_Host.
807  **/
scsi_host_scan_allowed(struct Scsi_Host * shost)808 static inline int scsi_host_scan_allowed(struct Scsi_Host *shost)
809 {
810 	return shost->shost_state == SHOST_RUNNING ||
811 	       shost->shost_state == SHOST_RECOVERY;
812 }
813 
814 extern void scsi_unblock_requests(struct Scsi_Host *);
815 extern void scsi_block_requests(struct Scsi_Host *);
816 
817 struct class_container;
818 
819 extern struct request_queue *__scsi_alloc_queue(struct Scsi_Host *shost,
820 						void (*) (struct request_queue *));
821 /*
822  * These two functions are used to allocate and free a pseudo device
823  * which will connect to the host adapter itself rather than any
824  * physical device.  You must deallocate when you are done with the
825  * thing.  This physical pseudo-device isn't real and won't be available
826  * from any high-level drivers.
827  */
828 extern void scsi_free_host_dev(struct scsi_device *);
829 extern struct scsi_device *scsi_get_host_dev(struct Scsi_Host *);
830 
831 /*
832  * DIF defines the exchange of protection information between
833  * initiator and SBC block device.
834  *
835  * DIX defines the exchange of protection information between OS and
836  * initiator.
837  */
838 enum scsi_host_prot_capabilities {
839 	SHOST_DIF_TYPE1_PROTECTION = 1 << 0, /* T10 DIF Type 1 */
840 	SHOST_DIF_TYPE2_PROTECTION = 1 << 1, /* T10 DIF Type 2 */
841 	SHOST_DIF_TYPE3_PROTECTION = 1 << 2, /* T10 DIF Type 3 */
842 
843 	SHOST_DIX_TYPE0_PROTECTION = 1 << 3, /* DIX between OS and HBA only */
844 	SHOST_DIX_TYPE1_PROTECTION = 1 << 4, /* DIX with DIF Type 1 */
845 	SHOST_DIX_TYPE2_PROTECTION = 1 << 5, /* DIX with DIF Type 2 */
846 	SHOST_DIX_TYPE3_PROTECTION = 1 << 6, /* DIX with DIF Type 3 */
847 };
848 
849 /*
850  * SCSI hosts which support the Data Integrity Extensions must
851  * indicate their capabilities by setting the prot_capabilities using
852  * this call.
853  */
scsi_host_set_prot(struct Scsi_Host * shost,unsigned int mask)854 static inline void scsi_host_set_prot(struct Scsi_Host *shost, unsigned int mask)
855 {
856 	shost->prot_capabilities = mask;
857 }
858 
scsi_host_get_prot(struct Scsi_Host * shost)859 static inline unsigned int scsi_host_get_prot(struct Scsi_Host *shost)
860 {
861 	return shost->prot_capabilities;
862 }
863 
scsi_host_prot_dma(struct Scsi_Host * shost)864 static inline int scsi_host_prot_dma(struct Scsi_Host *shost)
865 {
866 	return shost->prot_capabilities >= SHOST_DIX_TYPE0_PROTECTION;
867 }
868 
scsi_host_dif_capable(struct Scsi_Host * shost,unsigned int target_type)869 static inline unsigned int scsi_host_dif_capable(struct Scsi_Host *shost, unsigned int target_type)
870 {
871 	static unsigned char cap[] = { 0,
872 				       SHOST_DIF_TYPE1_PROTECTION,
873 				       SHOST_DIF_TYPE2_PROTECTION,
874 				       SHOST_DIF_TYPE3_PROTECTION };
875 
876 	return shost->prot_capabilities & cap[target_type] ? target_type : 0;
877 }
878 
scsi_host_dix_capable(struct Scsi_Host * shost,unsigned int target_type)879 static inline unsigned int scsi_host_dix_capable(struct Scsi_Host *shost, unsigned int target_type)
880 {
881 #if defined(CONFIG_BLK_DEV_INTEGRITY)
882 	static unsigned char cap[] = { SHOST_DIX_TYPE0_PROTECTION,
883 				       SHOST_DIX_TYPE1_PROTECTION,
884 				       SHOST_DIX_TYPE2_PROTECTION,
885 				       SHOST_DIX_TYPE3_PROTECTION };
886 
887 	return shost->prot_capabilities & cap[target_type];
888 #endif
889 	return 0;
890 }
891 
892 /*
893  * All DIX-capable initiators must support the T10-mandated CRC
894  * checksum.  Controllers can optionally implement the IP checksum
895  * scheme which has much lower impact on system performance.  Note
896  * that the main rationale for the checksum is to match integrity
897  * metadata with data.  Detecting bit errors are a job for ECC memory
898  * and buses.
899  */
900 
901 enum scsi_host_guard_type {
902 	SHOST_DIX_GUARD_CRC = 1 << 0,
903 	SHOST_DIX_GUARD_IP  = 1 << 1,
904 };
905 
scsi_host_set_guard(struct Scsi_Host * shost,unsigned char type)906 static inline void scsi_host_set_guard(struct Scsi_Host *shost, unsigned char type)
907 {
908 	shost->prot_guard_type = type;
909 }
910 
scsi_host_get_guard(struct Scsi_Host * shost)911 static inline unsigned char scsi_host_get_guard(struct Scsi_Host *shost)
912 {
913 	return shost->prot_guard_type;
914 }
915 
916 /* legacy interfaces */
917 extern struct Scsi_Host *scsi_register(struct scsi_host_template *, int);
918 extern void scsi_unregister(struct Scsi_Host *);
919 extern int scsi_host_set_state(struct Scsi_Host *, enum scsi_host_state);
920 
921 #endif /* _SCSI_SCSI_HOST_H */
922