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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
11struct request_queue;
12struct block_device;
13struct completion;
14struct module;
15struct scsi_cmnd;
16struct scsi_device;
17struct scsi_target;
18struct Scsi_Host;
19struct scsi_host_cmd_pool;
20struct scsi_transport_template;
21struct 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
46enum {
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
52struct 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60 * Status: OBSOLETE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67 * Status: OBSOLETE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 /*
359 * Name of proc directory
360 */
361 const char *proc_name;
362
363 /*
364 * Used to store the procfs directory if a driver implements the
365 * proc_info method.
366 */
367 struct proc_dir_entry *proc_dir;
368
369 /*
370 * This determines if we will use a non-interrupt driven
371 * or an interrupt driven scheme. It is set to the maximum number
372 * of simultaneous commands a given host adapter will accept.
373 */
374 int can_queue;
375
376 /*
377 * In many instances, especially where disconnect / reconnect are
378 * supported, our host also has an ID on the SCSI bus. If this is
379 * the case, then it must be reserved. Please set this_id to -1 if
380 * your setup is in single initiator mode, and the host lacks an
381 * ID.
382 */
383 int this_id;
384
385 /*
386 * This determines the degree to which the host adapter is capable
387 * of scatter-gather.
388 */
389 unsigned short sg_tablesize;
390 unsigned short sg_prot_tablesize;
391
392 /*
393 * Set this if the host adapter has limitations beside segment count.
394 */
395 unsigned short max_sectors;
396
397 /*
398 * DMA scatter gather segment boundary limit. A segment crossing this
399 * boundary will be split in two.
400 */
401 unsigned long dma_boundary;
402
403 /*
404 * This specifies "machine infinity" for host templates which don't
405 * limit the transfer size. Note this limit represents an absolute
406 * maximum, and may be over the transfer limits allowed for
407 * individual devices (e.g. 256 for SCSI-1).
408 */
409#define SCSI_DEFAULT_MAX_SECTORS 1024
410
411 /*
412 * True if this host adapter can make good use of linked commands.
413 * This will allow more than one command to be queued to a given
414 * unit on a given host. Set this to the maximum number of command
415 * blocks to be provided for each device. Set this to 1 for one
416 * command block per lun, 2 for two, etc. Do not set this to 0.
417 * You should make sure that the host adapter will do the right thing
418 * before you try setting this above 1.
419 */
420 short cmd_per_lun;
421
422 /*
423 * present contains counter indicating how many boards of this
424 * type were found when we did the scan.
425 */
426 unsigned char present;
427
428 /*
429 * This specifies the mode that a LLD supports.
430 */
431 unsigned supported_mode:2;
432
433 /*
434 * True if this host adapter uses unchecked DMA onto an ISA bus.
435 */
436 unsigned unchecked_isa_dma:1;
437
438 /*
439 * True if this host adapter can make good use of clustering.
440 * I originally thought that if the tablesize was large that it
441 * was a waste of CPU cycles to prepare a cluster list, but
442 * it works out that the Buslogic is faster if you use a smaller
443 * number of segments (i.e. use clustering). I guess it is
444 * inefficient.
445 */
446 unsigned use_clustering:1;
447
448 /*
449 * True for emulated SCSI host adapters (e.g. ATAPI).
450 */
451 unsigned emulated:1;
452
453 /*
454 * True if the low-level driver performs its own reset-settle delays.
455 */
456 unsigned skip_settle_delay:1;
457
458 /*
459 * True if we are using ordered write support.
460 */
461 unsigned ordered_tag:1;
462
463 /*
464 * Countdown for host blocking with no commands outstanding.
465 */
466 unsigned int max_host_blocked;
467
468 /*
469 * Default value for the blocking. If the queue is empty,
470 * host_blocked counts down in the request_fn until it restarts
471 * host operations as zero is reached.
472 *
473 * FIXME: This should probably be a value in the template
474 */
475#define SCSI_DEFAULT_HOST_BLOCKED 7
476
477 /*
478 * Pointer to the sysfs class properties for this host, NULL terminated.
479 */
480 struct device_attribute **shost_attrs;
481
482 /*
483 * Pointer to the SCSI device properties for this host, NULL terminated.
484 */
485 struct device_attribute **sdev_attrs;
486
487 /*
488 * List of hosts per template.
489 *
490 * This is only for use by scsi_module.c for legacy templates.
491 * For these access to it is synchronized implicitly by
492 * module_init/module_exit.
493 */
494 struct list_head legacy_hosts;
495
496 /*
497 * Vendor Identifier associated with the host
498 *
499 * Note: When specifying vendor_id, be sure to read the
500 * Vendor Type and ID formatting requirements specified in
501 * scsi_netlink.h
502 */
503 u64 vendor_id;
504};
505
506/*
507 * Temporary #define for host lock push down. Can be removed when all
508 * drivers have been updated to take advantage of unlocked
509 * queuecommand.
510 *
511 */
512#define DEF_SCSI_QCMD(func_name) \
513 int func_name(struct Scsi_Host *shost, struct scsi_cmnd *cmd) \
514 { \
515 unsigned long irq_flags; \
516 int rc; \
517 spin_lock_irqsave(shost->host_lock, irq_flags); \
518 scsi_cmd_get_serial(shost, cmd); \
519 rc = func_name##_lck (cmd, cmd->scsi_done); \
520 spin_unlock_irqrestore(shost->host_lock, irq_flags); \
521 return rc; \
522 }
523
524
525/*
526 * shost state: If you alter this, you also need to alter scsi_sysfs.c
527 * (for the ascii descriptions) and the state model enforcer:
528 * scsi_host_set_state()
529 */
530enum scsi_host_state {
531 SHOST_CREATED = 1,
532 SHOST_RUNNING,
533 SHOST_CANCEL,
534 SHOST_DEL,
535 SHOST_RECOVERY,
536 SHOST_CANCEL_RECOVERY,
537 SHOST_DEL_RECOVERY,
538};
539
540struct Scsi_Host {
541 /*
542 * __devices is protected by the host_lock, but you should
543 * usually use scsi_device_lookup / shost_for_each_device
544 * to access it and don't care about locking yourself.
545 * In the rare case of beeing in irq context you can use
546 * their __ prefixed variants with the lock held. NEVER
547 * access this list directly from a driver.
548 */
549 struct list_head __devices;
550 struct list_head __targets;
551
552 struct scsi_host_cmd_pool *cmd_pool;
553 spinlock_t free_list_lock;
554 struct list_head free_list; /* backup store of cmd structs */
555 struct list_head starved_list;
556
557 spinlock_t default_lock;
558 spinlock_t *host_lock;
559
560 struct mutex scan_mutex;/* serialize scanning activity */
561
562 struct list_head eh_cmd_q;
563 struct task_struct * ehandler; /* Error recovery thread. */
564 struct completion * eh_action; /* Wait for specific actions on the
565 host. */
566 wait_queue_head_t host_wait;
567 struct scsi_host_template *hostt;
568 struct scsi_transport_template *transportt;
569
570 /*
571 * Area to keep a shared tag map (if needed, will be
572 * NULL if not).
573 */
574 struct blk_queue_tag *bqt;
575
576 /*
577 * The following two fields are protected with host_lock;
578 * however, eh routines can safely access during eh processing
579 * without acquiring the lock.
580 */
581 unsigned int host_busy; /* commands actually active on low-level */
582 unsigned int host_failed; /* commands that failed. */
583 unsigned int host_eh_scheduled; /* EH scheduled without command */
584
585 unsigned int host_no; /* Used for IOCTL_GET_IDLUN, /proc/scsi et al. */
586 int resetting; /* if set, it means that last_reset is a valid value */
587 unsigned long last_reset;
588
589 /*
590 * These three parameters can be used to allow for wide scsi,
591 * and for host adapters that support multiple busses
592 * The first two should be set to 1 more than the actual max id
593 * or lun (i.e. 8 for normal systems).
594 */
595 unsigned int max_id;
596 unsigned int max_lun;
597 unsigned int max_channel;
598
599 /*
600 * This is a unique identifier that must be assigned so that we
601 * have some way of identifying each detected host adapter properly
602 * and uniquely. For hosts that do not support more than one card
603 * in the system at one time, this does not need to be set. It is
604 * initialized to 0 in scsi_register.
605 */
606 unsigned int unique_id;
607
608 /*
609 * The maximum length of SCSI commands that this host can accept.
610 * Probably 12 for most host adapters, but could be 16 for others.
611 * or 260 if the driver supports variable length cdbs.
612 * For drivers that don't set this field, a value of 12 is
613 * assumed.
614 */
615 unsigned short max_cmd_len;
616
617 int this_id;
618 int can_queue;
619 short cmd_per_lun;
620 short unsigned int sg_tablesize;
621 short unsigned int sg_prot_tablesize;
622 short unsigned int max_sectors;
623 unsigned long dma_boundary;
624 /*
625 * Used to assign serial numbers to the cmds.
626 * Protected by the host lock.
627 */
628 unsigned long cmd_serial_number;
629
630 unsigned active_mode:2;
631 unsigned unchecked_isa_dma:1;
632 unsigned use_clustering:1;
633 unsigned use_blk_tcq:1;
634
635 /*
636 * Host has requested that no further requests come through for the
637 * time being.
638 */
639 unsigned host_self_blocked:1;
640
641 /*
642 * Host uses correct SCSI ordering not PC ordering. The bit is
643 * set for the minority of drivers whose authors actually read
644 * the spec ;).
645 */
646 unsigned reverse_ordering:1;
647
648 /*
649 * Ordered write support
650 */
651 unsigned ordered_tag:1;
652
653 /* Task mgmt function in progress */
654 unsigned tmf_in_progress:1;
655
656 /* Asynchronous scan in progress */
657 unsigned async_scan:1;
658
659 /*
660 * Optional work queue to be utilized by the transport
661 */
662 char work_q_name[20];
663 struct workqueue_struct *work_q;
664
665 /*
666 * Host has rejected a command because it was busy.
667 */
668 unsigned int host_blocked;
669
670 /*
671 * Value host_blocked counts down from
672 */
673 unsigned int max_host_blocked;
674
675 /* Protection Information */
676 unsigned int prot_capabilities;
677 unsigned char prot_guard_type;
678
679 /*
680 * q used for scsi_tgt msgs, async events or any other requests that
681 * need to be processed in userspace
682 */
683 struct request_queue *uspace_req_q;
684
685 /* legacy crap */
686 unsigned long base;
687 unsigned long io_port;
688 unsigned char n_io_port;
689 unsigned char dma_channel;
690 unsigned int irq;
691
692
693 enum scsi_host_state shost_state;
694
695 /* ldm bits */
696 struct device shost_gendev, shost_dev;
697
698 /*
699 * List of hosts per template.
700 *
701 * This is only for use by scsi_module.c for legacy templates.
702 * For these access to it is synchronized implicitly by
703 * module_init/module_exit.
704 */
705 struct list_head sht_legacy_list;
706
707 /*
708 * Points to the transport data (if any) which is allocated
709 * separately
710 */
711 void *shost_data;
712
713 /*
714 * Points to the physical bus device we'd use to do DMA
715 * Needed just in case we have virtual hosts.
716 */
717 struct device *dma_dev;
718
719 /*
720 * We should ensure that this is aligned, both for better performance
721 * and also because some compilers (m68k) don't automatically force
722 * alignment to a long boundary.
723 */
724 unsigned long hostdata[0] /* Used for storage of host specific stuff */
725 __attribute__ ((aligned (sizeof(unsigned long))));
726};
727
728#define class_to_shost(d) \
729 container_of(d, struct Scsi_Host, shost_dev)
730
731#define shost_printk(prefix, shost, fmt, a...) \
732 dev_printk(prefix, &(shost)->shost_gendev, fmt, ##a)
733
734static inline void *shost_priv(struct Scsi_Host *shost)
735{
736 return (void *)shost->hostdata;
737}
738
739int scsi_is_host_device(const struct device *);
740
741static inline struct Scsi_Host *dev_to_shost(struct device *dev)
742{
743 while (!scsi_is_host_device(dev)) {
744 if (!dev->parent)
745 return NULL;
746 dev = dev->parent;
747 }
748 return container_of(dev, struct Scsi_Host, shost_gendev);
749}
750
751static inline int scsi_host_in_recovery(struct Scsi_Host *shost)
752{
753 return shost->shost_state == SHOST_RECOVERY ||
754 shost->shost_state == SHOST_CANCEL_RECOVERY ||
755 shost->shost_state == SHOST_DEL_RECOVERY ||
756 shost->tmf_in_progress;
757}
758
759extern int scsi_queue_work(struct Scsi_Host *, struct work_struct *);
760extern void scsi_flush_work(struct Scsi_Host *);
761
762extern struct Scsi_Host *scsi_host_alloc(struct scsi_host_template *, int);
763extern int __must_check scsi_add_host_with_dma(struct Scsi_Host *,
764 struct device *,
765 struct device *);
766extern void scsi_scan_host(struct Scsi_Host *);
767extern void scsi_rescan_device(struct device *);
768extern void scsi_remove_host(struct Scsi_Host *);
769extern struct Scsi_Host *scsi_host_get(struct Scsi_Host *);
770extern void scsi_host_put(struct Scsi_Host *t);
771extern struct Scsi_Host *scsi_host_lookup(unsigned short);
772extern const char *scsi_host_state_name(enum scsi_host_state);
773extern void scsi_cmd_get_serial(struct Scsi_Host *, struct scsi_cmnd *);
774
775extern u64 scsi_calculate_bounce_limit(struct Scsi_Host *);
776
777static inline int __must_check scsi_add_host(struct Scsi_Host *host,
778 struct device *dev)
779{
780 return scsi_add_host_with_dma(host, dev, dev);
781}
782
783static inline struct device *scsi_get_device(struct Scsi_Host *shost)
784{
785 return shost->shost_gendev.parent;
786}
787
788/**
789 * scsi_host_scan_allowed - Is scanning of this host allowed
790 * @shost: Pointer to Scsi_Host.
791 **/
792static inline int scsi_host_scan_allowed(struct Scsi_Host *shost)
793{
794 return shost->shost_state == SHOST_RUNNING;
795}
796
797extern void scsi_unblock_requests(struct Scsi_Host *);
798extern void scsi_block_requests(struct Scsi_Host *);
799
800struct class_container;
801
802extern struct request_queue *__scsi_alloc_queue(struct Scsi_Host *shost,
803 void (*) (struct request_queue *));
804/*
805 * These two functions are used to allocate and free a pseudo device
806 * which will connect to the host adapter itself rather than any
807 * physical device. You must deallocate when you are done with the
808 * thing. This physical pseudo-device isn't real and won't be available
809 * from any high-level drivers.
810 */
811extern void scsi_free_host_dev(struct scsi_device *);
812extern struct scsi_device *scsi_get_host_dev(struct Scsi_Host *);
813
814/*
815 * DIF defines the exchange of protection information between
816 * initiator and SBC block device.
817 *
818 * DIX defines the exchange of protection information between OS and
819 * initiator.
820 */
821enum scsi_host_prot_capabilities {
822 SHOST_DIF_TYPE1_PROTECTION = 1 << 0, /* T10 DIF Type 1 */
823 SHOST_DIF_TYPE2_PROTECTION = 1 << 1, /* T10 DIF Type 2 */
824 SHOST_DIF_TYPE3_PROTECTION = 1 << 2, /* T10 DIF Type 3 */
825
826 SHOST_DIX_TYPE0_PROTECTION = 1 << 3, /* DIX between OS and HBA only */
827 SHOST_DIX_TYPE1_PROTECTION = 1 << 4, /* DIX with DIF Type 1 */
828 SHOST_DIX_TYPE2_PROTECTION = 1 << 5, /* DIX with DIF Type 2 */
829 SHOST_DIX_TYPE3_PROTECTION = 1 << 6, /* DIX with DIF Type 3 */
830};
831
832/*
833 * SCSI hosts which support the Data Integrity Extensions must
834 * indicate their capabilities by setting the prot_capabilities using
835 * this call.
836 */
837static inline void scsi_host_set_prot(struct Scsi_Host *shost, unsigned int mask)
838{
839 shost->prot_capabilities = mask;
840}
841
842static inline unsigned int scsi_host_get_prot(struct Scsi_Host *shost)
843{
844 return shost->prot_capabilities;
845}
846
847static inline int scsi_host_prot_dma(struct Scsi_Host *shost)
848{
849 return shost->prot_capabilities >= SHOST_DIX_TYPE0_PROTECTION;
850}
851
852static inline unsigned int scsi_host_dif_capable(struct Scsi_Host *shost, unsigned int target_type)
853{
854 static unsigned char cap[] = { 0,
855 SHOST_DIF_TYPE1_PROTECTION,
856 SHOST_DIF_TYPE2_PROTECTION,
857 SHOST_DIF_TYPE3_PROTECTION };
858
859 return shost->prot_capabilities & cap[target_type] ? target_type : 0;
860}
861
862static inline unsigned int scsi_host_dix_capable(struct Scsi_Host *shost, unsigned int target_type)
863{
864#if defined(CONFIG_BLK_DEV_INTEGRITY)
865 static unsigned char cap[] = { SHOST_DIX_TYPE0_PROTECTION,
866 SHOST_DIX_TYPE1_PROTECTION,
867 SHOST_DIX_TYPE2_PROTECTION,
868 SHOST_DIX_TYPE3_PROTECTION };
869
870 return shost->prot_capabilities & cap[target_type];
871#endif
872 return 0;
873}
874
875/*
876 * All DIX-capable initiators must support the T10-mandated CRC
877 * checksum. Controllers can optionally implement the IP checksum
878 * scheme which has much lower impact on system performance. Note
879 * that the main rationale for the checksum is to match integrity
880 * metadata with data. Detecting bit errors are a job for ECC memory
881 * and buses.
882 */
883
884enum scsi_host_guard_type {
885 SHOST_DIX_GUARD_CRC = 1 << 0,
886 SHOST_DIX_GUARD_IP = 1 << 1,
887};
888
889static inline void scsi_host_set_guard(struct Scsi_Host *shost, unsigned char type)
890{
891 shost->prot_guard_type = type;
892}
893
894static inline unsigned char scsi_host_get_guard(struct Scsi_Host *shost)
895{
896 return shost->prot_guard_type;
897}
898
899/* legacy interfaces */
900extern struct Scsi_Host *scsi_register(struct scsi_host_template *, int);
901extern void scsi_unregister(struct Scsi_Host *);
902extern int scsi_host_set_state(struct Scsi_Host *, enum scsi_host_state);
903
904#endif /* _SCSI_SCSI_HOST_H */
1#ifndef _SCSI_SCSI_HOST_H
2#define _SCSI_SCSI_HOST_H
3
4#include <linux/device.h>
5#include <linux/list.h>
6#include <linux/types.h>
7#include <linux/workqueue.h>
8#include <linux/mutex.h>
9#include <linux/seq_file.h>
10#include <scsi/scsi.h>
11
12struct request_queue;
13struct block_device;
14struct completion;
15struct module;
16struct scsi_cmnd;
17struct scsi_device;
18struct scsi_host_cmd_pool;
19struct scsi_target;
20struct Scsi_Host;
21struct scsi_host_cmd_pool;
22struct scsi_transport_template;
23struct blk_queue_tags;
24
25
26/*
27 * The various choices mean:
28 * NONE: Self evident. Host adapter is not capable of scatter-gather.
29 * ALL: Means that the host adapter module can do scatter-gather,
30 * and that there is no limit to the size of the table to which
31 * we scatter/gather data. The value we set here is the maximum
32 * single element sglist. To use chained sglists, the adapter
33 * has to set a value beyond ALL (and correctly use the chain
34 * handling API.
35 * Anything else: Indicates the maximum number of chains that can be
36 * used in one scatter-gather request.
37 */
38#define SG_NONE 0
39#define SG_ALL SCSI_MAX_SG_SEGMENTS
40
41#define MODE_UNKNOWN 0x00
42#define MODE_INITIATOR 0x01
43#define MODE_TARGET 0x02
44
45#define DISABLE_CLUSTERING 0
46#define ENABLE_CLUSTERING 1
47
48enum {
49 SCSI_QDEPTH_DEFAULT, /* default requested change, e.g. from sysfs */
50 SCSI_QDEPTH_QFULL, /* scsi-ml requested due to queue full */
51 SCSI_QDEPTH_RAMP_UP, /* scsi-ml requested due to threshold event */
52};
53
54struct scsi_host_template {
55 struct module *module;
56 const char *name;
57
58 /*
59 * Used to initialize old-style drivers. For new-style drivers
60 * just perform all work in your module initialization function.
61 *
62 * Status: OBSOLETE
63 */
64 int (* detect)(struct scsi_host_template *);
65
66 /*
67 * Used as unload callback for hosts with old-style drivers.
68 *
69 * Status: OBSOLETE
70 */
71 int (* release)(struct Scsi_Host *);
72
73 /*
74 * The info function will return whatever useful information the
75 * developer sees fit. If not provided, then the name field will
76 * be used instead.
77 *
78 * Status: OPTIONAL
79 */
80 const char *(* info)(struct Scsi_Host *);
81
82 /*
83 * Ioctl interface
84 *
85 * Status: OPTIONAL
86 */
87 int (* ioctl)(struct scsi_device *dev, int cmd, void __user *arg);
88
89
90#ifdef CONFIG_COMPAT
91 /*
92 * Compat handler. Handle 32bit ABI.
93 * When unknown ioctl is passed return -ENOIOCTLCMD.
94 *
95 * Status: OPTIONAL
96 */
97 int (* compat_ioctl)(struct scsi_device *dev, int cmd, void __user *arg);
98#endif
99
100 /*
101 * The queuecommand function is used to queue up a scsi
102 * command block to the LLDD. When the driver finished
103 * processing the command the done callback is invoked.
104 *
105 * If queuecommand returns 0, then the HBA has accepted the
106 * command. The done() function must be called on the command
107 * when the driver has finished with it. (you may call done on the
108 * command before queuecommand returns, but in this case you
109 * *must* return 0 from queuecommand).
110 *
111 * Queuecommand may also reject the command, in which case it may
112 * not touch the command and must not call done() for it.
113 *
114 * There are two possible rejection returns:
115 *
116 * SCSI_MLQUEUE_DEVICE_BUSY: Block this device temporarily, but
117 * allow commands to other devices serviced by this host.
118 *
119 * SCSI_MLQUEUE_HOST_BUSY: Block all devices served by this
120 * host temporarily.
121 *
122 * For compatibility, any other non-zero return is treated the
123 * same as SCSI_MLQUEUE_HOST_BUSY.
124 *
125 * NOTE: "temporarily" means either until the next command for#
126 * this device/host completes, or a period of time determined by
127 * I/O pressure in the system if there are no other outstanding
128 * commands.
129 *
130 * STATUS: REQUIRED
131 */
132 int (* queuecommand)(struct Scsi_Host *, struct scsi_cmnd *);
133
134 /*
135 * The transfer functions are used to queue a scsi command to
136 * the LLD. When the driver is finished processing the command
137 * the done callback is invoked.
138 *
139 * This is called to inform the LLD to transfer
140 * scsi_bufflen(cmd) bytes. scsi_sg_count(cmd) speciefies the
141 * number of scatterlist entried in the command and
142 * scsi_sglist(cmd) returns the scatterlist.
143 *
144 * return values: see queuecommand
145 *
146 * If the LLD accepts the cmd, it should set the result to an
147 * appropriate value when completed before calling the done function.
148 *
149 * STATUS: REQUIRED FOR TARGET DRIVERS
150 */
151 /* TODO: rename */
152 int (* transfer_response)(struct scsi_cmnd *,
153 void (*done)(struct scsi_cmnd *));
154
155 /*
156 * This is an error handling strategy routine. You don't need to
157 * define one of these if you don't want to - there is a default
158 * routine that is present that should work in most cases. For those
159 * driver authors that have the inclination and ability to write their
160 * own strategy routine, this is where it is specified. Note - the
161 * strategy routine is *ALWAYS* run in the context of the kernel eh
162 * thread. Thus you are guaranteed to *NOT* be in an interrupt
163 * handler when you execute this, and you are also guaranteed to
164 * *NOT* have any other commands being queued while you are in the
165 * strategy routine. When you return from this function, operations
166 * return to normal.
167 *
168 * See scsi_error.c scsi_unjam_host for additional comments about
169 * what this function should and should not be attempting to do.
170 *
171 * Status: REQUIRED (at least one of them)
172 */
173 int (* eh_abort_handler)(struct scsi_cmnd *);
174 int (* eh_device_reset_handler)(struct scsi_cmnd *);
175 int (* eh_target_reset_handler)(struct scsi_cmnd *);
176 int (* eh_bus_reset_handler)(struct scsi_cmnd *);
177 int (* eh_host_reset_handler)(struct scsi_cmnd *);
178
179 /*
180 * Before the mid layer attempts to scan for a new device where none
181 * currently exists, it will call this entry in your driver. Should
182 * your driver need to allocate any structs or perform any other init
183 * items in order to send commands to a currently unused target/lun
184 * combo, then this is where you can perform those allocations. This
185 * is specifically so that drivers won't have to perform any kind of
186 * "is this a new device" checks in their queuecommand routine,
187 * thereby making the hot path a bit quicker.
188 *
189 * Return values: 0 on success, non-0 on failure
190 *
191 * Deallocation: If we didn't find any devices at this ID, you will
192 * get an immediate call to slave_destroy(). If we find something
193 * here then you will get a call to slave_configure(), then the
194 * device will be used for however long it is kept around, then when
195 * the device is removed from the system (or * possibly at reboot
196 * time), you will then get a call to slave_destroy(). This is
197 * assuming you implement slave_configure and slave_destroy.
198 * However, if you allocate memory and hang it off the device struct,
199 * then you must implement the slave_destroy() routine at a minimum
200 * in order to avoid leaking memory
201 * each time a device is tore down.
202 *
203 * Status: OPTIONAL
204 */
205 int (* slave_alloc)(struct scsi_device *);
206
207 /*
208 * Once the device has responded to an INQUIRY and we know the
209 * device is online, we call into the low level driver with the
210 * struct scsi_device *. If the low level device driver implements
211 * this function, it *must* perform the task of setting the queue
212 * depth on the device. All other tasks are optional and depend
213 * on what the driver supports and various implementation details.
214 *
215 * Things currently recommended to be handled at this time include:
216 *
217 * 1. Setting the device queue depth. Proper setting of this is
218 * described in the comments for scsi_adjust_queue_depth.
219 * 2. Determining if the device supports the various synchronous
220 * negotiation protocols. The device struct will already have
221 * responded to INQUIRY and the results of the standard items
222 * will have been shoved into the various device flag bits, eg.
223 * device->sdtr will be true if the device supports SDTR messages.
224 * 3. Allocating command structs that the device will need.
225 * 4. Setting the default timeout on this device (if needed).
226 * 5. Anything else the low level driver might want to do on a device
227 * specific setup basis...
228 * 6. Return 0 on success, non-0 on error. The device will be marked
229 * as offline on error so that no access will occur. If you return
230 * non-0, your slave_destroy routine will never get called for this
231 * device, so don't leave any loose memory hanging around, clean
232 * up after yourself before returning non-0
233 *
234 * Status: OPTIONAL
235 */
236 int (* slave_configure)(struct scsi_device *);
237
238 /*
239 * Immediately prior to deallocating the device and after all activity
240 * has ceased the mid layer calls this point so that the low level
241 * driver may completely detach itself from the scsi device and vice
242 * versa. The low level driver is responsible for freeing any memory
243 * it allocated in the slave_alloc or slave_configure calls.
244 *
245 * Status: OPTIONAL
246 */
247 void (* slave_destroy)(struct scsi_device *);
248
249 /*
250 * Before the mid layer attempts to scan for a new device attached
251 * to a target where no target currently exists, it will call this
252 * entry in your driver. Should your driver need to allocate any
253 * structs or perform any other init items in order to send commands
254 * to a currently unused target, then this is where you can perform
255 * those allocations.
256 *
257 * Return values: 0 on success, non-0 on failure
258 *
259 * Status: OPTIONAL
260 */
261 int (* target_alloc)(struct scsi_target *);
262
263 /*
264 * Immediately prior to deallocating the target structure, and
265 * after all activity to attached scsi devices has ceased, the
266 * midlayer calls this point so that the driver may deallocate
267 * and terminate any references to the target.
268 *
269 * Status: OPTIONAL
270 */
271 void (* target_destroy)(struct scsi_target *);
272
273 /*
274 * If a host has the ability to discover targets on its own instead
275 * of scanning the entire bus, it can fill in this function and
276 * call scsi_scan_host(). This function will be called periodically
277 * until it returns 1 with the scsi_host and the elapsed time of
278 * the scan in jiffies.
279 *
280 * Status: OPTIONAL
281 */
282 int (* scan_finished)(struct Scsi_Host *, unsigned long);
283
284 /*
285 * If the host wants to be called before the scan starts, but
286 * after the midlayer has set up ready for the scan, it can fill
287 * in this function.
288 *
289 * Status: OPTIONAL
290 */
291 void (* scan_start)(struct Scsi_Host *);
292
293 /*
294 * Fill in this function to allow the queue depth of this host
295 * to be changeable (on a per device basis). Returns either
296 * the current queue depth setting (may be different from what
297 * was passed in) or an error. An error should only be
298 * returned if the requested depth is legal but the driver was
299 * unable to set it. If the requested depth is illegal, the
300 * driver should set and return the closest legal queue depth.
301 *
302 * Status: OPTIONAL
303 */
304 int (* change_queue_depth)(struct scsi_device *, int, int);
305
306 /*
307 * Fill in this function to allow the changing of tag types
308 * (this also allows the enabling/disabling of tag command
309 * queueing). An error should only be returned if something
310 * went wrong in the driver while trying to set the tag type.
311 * If the driver doesn't support the requested tag type, then
312 * it should set the closest type it does support without
313 * returning an error. Returns the actual tag type set.
314 *
315 * Status: OPTIONAL
316 */
317 int (* change_queue_type)(struct scsi_device *, int);
318
319 /*
320 * This function determines the BIOS parameters for a given
321 * harddisk. These tend to be numbers that are made up by
322 * the host adapter. Parameters:
323 * size, device, list (heads, sectors, cylinders)
324 *
325 * Status: OPTIONAL
326 */
327 int (* bios_param)(struct scsi_device *, struct block_device *,
328 sector_t, int []);
329
330 /*
331 * This function is called when one or more partitions on the
332 * device reach beyond the end of the device.
333 *
334 * Status: OPTIONAL
335 */
336 void (*unlock_native_capacity)(struct scsi_device *);
337
338 /*
339 * Can be used to export driver statistics and other infos to the
340 * world outside the kernel ie. userspace and it also provides an
341 * interface to feed the driver with information.
342 *
343 * Status: OBSOLETE
344 */
345 int (*show_info)(struct seq_file *, struct Scsi_Host *);
346 int (*write_info)(struct Scsi_Host *, char *, int);
347
348 /*
349 * This is an optional routine that allows the transport to become
350 * involved when a scsi io timer fires. The return value tells the
351 * timer routine how to finish the io timeout handling:
352 * EH_HANDLED: I fixed the error, please complete the command
353 * EH_RESET_TIMER: I need more time, reset the timer and
354 * begin counting again
355 * EH_NOT_HANDLED Begin normal error recovery
356 *
357 * Status: OPTIONAL
358 */
359 enum blk_eh_timer_return (*eh_timed_out)(struct scsi_cmnd *);
360
361 /* This is an optional routine that allows transport to initiate
362 * LLD adapter or firmware reset using sysfs attribute.
363 *
364 * Return values: 0 on success, -ve value on failure.
365 *
366 * Status: OPTIONAL
367 */
368
369 int (*host_reset)(struct Scsi_Host *shost, int reset_type);
370#define SCSI_ADAPTER_RESET 1
371#define SCSI_FIRMWARE_RESET 2
372
373
374 /*
375 * Name of proc directory
376 */
377 const char *proc_name;
378
379 /*
380 * Used to store the procfs directory if a driver implements the
381 * show_info method.
382 */
383 struct proc_dir_entry *proc_dir;
384
385 /*
386 * This determines if we will use a non-interrupt driven
387 * or an interrupt driven scheme. It is set to the maximum number
388 * of simultaneous commands a given host adapter will accept.
389 */
390 int can_queue;
391
392 /*
393 * In many instances, especially where disconnect / reconnect are
394 * supported, our host also has an ID on the SCSI bus. If this is
395 * the case, then it must be reserved. Please set this_id to -1 if
396 * your setup is in single initiator mode, and the host lacks an
397 * ID.
398 */
399 int this_id;
400
401 /*
402 * This determines the degree to which the host adapter is capable
403 * of scatter-gather.
404 */
405 unsigned short sg_tablesize;
406 unsigned short sg_prot_tablesize;
407
408 /*
409 * Set this if the host adapter has limitations beside segment count.
410 */
411 unsigned short max_sectors;
412
413 /*
414 * DMA scatter gather segment boundary limit. A segment crossing this
415 * boundary will be split in two.
416 */
417 unsigned long dma_boundary;
418
419 /*
420 * This specifies "machine infinity" for host templates which don't
421 * limit the transfer size. Note this limit represents an absolute
422 * maximum, and may be over the transfer limits allowed for
423 * individual devices (e.g. 256 for SCSI-1).
424 */
425#define SCSI_DEFAULT_MAX_SECTORS 1024
426
427 /*
428 * True if this host adapter can make good use of linked commands.
429 * This will allow more than one command to be queued to a given
430 * unit on a given host. Set this to the maximum number of command
431 * blocks to be provided for each device. Set this to 1 for one
432 * command block per lun, 2 for two, etc. Do not set this to 0.
433 * You should make sure that the host adapter will do the right thing
434 * before you try setting this above 1.
435 */
436 short cmd_per_lun;
437
438 /*
439 * present contains counter indicating how many boards of this
440 * type were found when we did the scan.
441 */
442 unsigned char present;
443
444 /*
445 * This specifies the mode that a LLD supports.
446 */
447 unsigned supported_mode:2;
448
449 /*
450 * True if this host adapter uses unchecked DMA onto an ISA bus.
451 */
452 unsigned unchecked_isa_dma:1;
453
454 /*
455 * True if this host adapter can make good use of clustering.
456 * I originally thought that if the tablesize was large that it
457 * was a waste of CPU cycles to prepare a cluster list, but
458 * it works out that the Buslogic is faster if you use a smaller
459 * number of segments (i.e. use clustering). I guess it is
460 * inefficient.
461 */
462 unsigned use_clustering:1;
463
464 /*
465 * True for emulated SCSI host adapters (e.g. ATAPI).
466 */
467 unsigned emulated:1;
468
469 /*
470 * True if the low-level driver performs its own reset-settle delays.
471 */
472 unsigned skip_settle_delay:1;
473
474 /*
475 * True if we are using ordered write support.
476 */
477 unsigned ordered_tag:1;
478
479 /* True if the controller does not support WRITE SAME */
480 unsigned no_write_same:1;
481
482 /*
483 * True if asynchronous aborts are not supported
484 */
485 unsigned no_async_abort:1;
486
487 /*
488 * Countdown for host blocking with no commands outstanding.
489 */
490 unsigned int max_host_blocked;
491
492 /*
493 * Default value for the blocking. If the queue is empty,
494 * host_blocked counts down in the request_fn until it restarts
495 * host operations as zero is reached.
496 *
497 * FIXME: This should probably be a value in the template
498 */
499#define SCSI_DEFAULT_HOST_BLOCKED 7
500
501 /*
502 * Pointer to the sysfs class properties for this host, NULL terminated.
503 */
504 struct device_attribute **shost_attrs;
505
506 /*
507 * Pointer to the SCSI device properties for this host, NULL terminated.
508 */
509 struct device_attribute **sdev_attrs;
510
511 /*
512 * List of hosts per template.
513 *
514 * This is only for use by scsi_module.c for legacy templates.
515 * For these access to it is synchronized implicitly by
516 * module_init/module_exit.
517 */
518 struct list_head legacy_hosts;
519
520 /*
521 * Vendor Identifier associated with the host
522 *
523 * Note: When specifying vendor_id, be sure to read the
524 * Vendor Type and ID formatting requirements specified in
525 * scsi_netlink.h
526 */
527 u64 vendor_id;
528
529 /*
530 * Additional per-command data allocated for the driver.
531 */
532 unsigned int cmd_size;
533 struct scsi_host_cmd_pool *cmd_pool;
534};
535
536/*
537 * Temporary #define for host lock push down. Can be removed when all
538 * drivers have been updated to take advantage of unlocked
539 * queuecommand.
540 *
541 */
542#define DEF_SCSI_QCMD(func_name) \
543 int func_name(struct Scsi_Host *shost, struct scsi_cmnd *cmd) \
544 { \
545 unsigned long irq_flags; \
546 int rc; \
547 spin_lock_irqsave(shost->host_lock, irq_flags); \
548 scsi_cmd_get_serial(shost, cmd); \
549 rc = func_name##_lck (cmd, cmd->scsi_done); \
550 spin_unlock_irqrestore(shost->host_lock, irq_flags); \
551 return rc; \
552 }
553
554
555/*
556 * shost state: If you alter this, you also need to alter scsi_sysfs.c
557 * (for the ascii descriptions) and the state model enforcer:
558 * scsi_host_set_state()
559 */
560enum scsi_host_state {
561 SHOST_CREATED = 1,
562 SHOST_RUNNING,
563 SHOST_CANCEL,
564 SHOST_DEL,
565 SHOST_RECOVERY,
566 SHOST_CANCEL_RECOVERY,
567 SHOST_DEL_RECOVERY,
568};
569
570struct Scsi_Host {
571 /*
572 * __devices is protected by the host_lock, but you should
573 * usually use scsi_device_lookup / shost_for_each_device
574 * to access it and don't care about locking yourself.
575 * In the rare case of beeing in irq context you can use
576 * their __ prefixed variants with the lock held. NEVER
577 * access this list directly from a driver.
578 */
579 struct list_head __devices;
580 struct list_head __targets;
581
582 struct scsi_host_cmd_pool *cmd_pool;
583 spinlock_t free_list_lock;
584 struct list_head free_list; /* backup store of cmd structs */
585 struct list_head starved_list;
586
587 spinlock_t default_lock;
588 spinlock_t *host_lock;
589
590 struct mutex scan_mutex;/* serialize scanning activity */
591
592 struct list_head eh_cmd_q;
593 struct task_struct * ehandler; /* Error recovery thread. */
594 struct completion * eh_action; /* Wait for specific actions on the
595 host. */
596 wait_queue_head_t host_wait;
597 struct scsi_host_template *hostt;
598 struct scsi_transport_template *transportt;
599
600 /*
601 * Area to keep a shared tag map (if needed, will be
602 * NULL if not).
603 */
604 struct blk_queue_tag *bqt;
605
606 /*
607 * The following two fields are protected with host_lock;
608 * however, eh routines can safely access during eh processing
609 * without acquiring the lock.
610 */
611 unsigned int host_busy; /* commands actually active on low-level */
612 unsigned int host_failed; /* commands that failed. */
613 unsigned int host_eh_scheduled; /* EH scheduled without command */
614
615 unsigned int host_no; /* Used for IOCTL_GET_IDLUN, /proc/scsi et al. */
616
617 /* next two fields are used to bound the time spent in error handling */
618 int eh_deadline;
619 unsigned long last_reset;
620
621
622 /*
623 * These three parameters can be used to allow for wide scsi,
624 * and for host adapters that support multiple busses
625 * The first two should be set to 1 more than the actual max id
626 * or lun (i.e. 8 for normal systems).
627 */
628 unsigned int max_id;
629 unsigned int max_lun;
630 unsigned int max_channel;
631
632 /*
633 * This is a unique identifier that must be assigned so that we
634 * have some way of identifying each detected host adapter properly
635 * and uniquely. For hosts that do not support more than one card
636 * in the system at one time, this does not need to be set. It is
637 * initialized to 0 in scsi_register.
638 */
639 unsigned int unique_id;
640
641 /*
642 * The maximum length of SCSI commands that this host can accept.
643 * Probably 12 for most host adapters, but could be 16 for others.
644 * or 260 if the driver supports variable length cdbs.
645 * For drivers that don't set this field, a value of 12 is
646 * assumed.
647 */
648 unsigned short max_cmd_len;
649
650 int this_id;
651 int can_queue;
652 short cmd_per_lun;
653 short unsigned int sg_tablesize;
654 short unsigned int sg_prot_tablesize;
655 short unsigned int max_sectors;
656 unsigned long dma_boundary;
657 /*
658 * Used to assign serial numbers to the cmds.
659 * Protected by the host lock.
660 */
661 unsigned long cmd_serial_number;
662
663 unsigned active_mode:2;
664 unsigned unchecked_isa_dma:1;
665 unsigned use_clustering:1;
666 unsigned use_blk_tcq:1;
667
668 /*
669 * Host has requested that no further requests come through for the
670 * time being.
671 */
672 unsigned host_self_blocked:1;
673
674 /*
675 * Host uses correct SCSI ordering not PC ordering. The bit is
676 * set for the minority of drivers whose authors actually read
677 * the spec ;).
678 */
679 unsigned reverse_ordering:1;
680
681 /*
682 * Ordered write support
683 */
684 unsigned ordered_tag:1;
685
686 /* Task mgmt function in progress */
687 unsigned tmf_in_progress:1;
688
689 /* Asynchronous scan in progress */
690 unsigned async_scan:1;
691
692 /* Don't resume host in EH */
693 unsigned eh_noresume:1;
694
695 /* The controller does not support WRITE SAME */
696 unsigned no_write_same:1;
697
698 /*
699 * Optional work queue to be utilized by the transport
700 */
701 char work_q_name[20];
702 struct workqueue_struct *work_q;
703
704 /*
705 * Task management function work queue
706 */
707 struct workqueue_struct *tmf_work_q;
708
709 /*
710 * Host has rejected a command because it was busy.
711 */
712 unsigned int host_blocked;
713
714 /*
715 * Value host_blocked counts down from
716 */
717 unsigned int max_host_blocked;
718
719 /* Protection Information */
720 unsigned int prot_capabilities;
721 unsigned char prot_guard_type;
722
723 /*
724 * q used for scsi_tgt msgs, async events or any other requests that
725 * need to be processed in userspace
726 */
727 struct request_queue *uspace_req_q;
728
729 /* legacy crap */
730 unsigned long base;
731 unsigned long io_port;
732 unsigned char n_io_port;
733 unsigned char dma_channel;
734 unsigned int irq;
735
736
737 enum scsi_host_state shost_state;
738
739 /* ldm bits */
740 struct device shost_gendev, shost_dev;
741
742 /*
743 * List of hosts per template.
744 *
745 * This is only for use by scsi_module.c for legacy templates.
746 * For these access to it is synchronized implicitly by
747 * module_init/module_exit.
748 */
749 struct list_head sht_legacy_list;
750
751 /*
752 * Points to the transport data (if any) which is allocated
753 * separately
754 */
755 void *shost_data;
756
757 /*
758 * Points to the physical bus device we'd use to do DMA
759 * Needed just in case we have virtual hosts.
760 */
761 struct device *dma_dev;
762
763 /*
764 * We should ensure that this is aligned, both for better performance
765 * and also because some compilers (m68k) don't automatically force
766 * alignment to a long boundary.
767 */
768 unsigned long hostdata[0] /* Used for storage of host specific stuff */
769 __attribute__ ((aligned (sizeof(unsigned long))));
770};
771
772#define class_to_shost(d) \
773 container_of(d, struct Scsi_Host, shost_dev)
774
775#define shost_printk(prefix, shost, fmt, a...) \
776 dev_printk(prefix, &(shost)->shost_gendev, fmt, ##a)
777
778static inline void *shost_priv(struct Scsi_Host *shost)
779{
780 return (void *)shost->hostdata;
781}
782
783int scsi_is_host_device(const struct device *);
784
785static inline struct Scsi_Host *dev_to_shost(struct device *dev)
786{
787 while (!scsi_is_host_device(dev)) {
788 if (!dev->parent)
789 return NULL;
790 dev = dev->parent;
791 }
792 return container_of(dev, struct Scsi_Host, shost_gendev);
793}
794
795static inline int scsi_host_in_recovery(struct Scsi_Host *shost)
796{
797 return shost->shost_state == SHOST_RECOVERY ||
798 shost->shost_state == SHOST_CANCEL_RECOVERY ||
799 shost->shost_state == SHOST_DEL_RECOVERY ||
800 shost->tmf_in_progress;
801}
802
803extern int scsi_queue_work(struct Scsi_Host *, struct work_struct *);
804extern void scsi_flush_work(struct Scsi_Host *);
805
806extern struct Scsi_Host *scsi_host_alloc(struct scsi_host_template *, int);
807extern int __must_check scsi_add_host_with_dma(struct Scsi_Host *,
808 struct device *,
809 struct device *);
810extern void scsi_scan_host(struct Scsi_Host *);
811extern void scsi_rescan_device(struct device *);
812extern void scsi_remove_host(struct Scsi_Host *);
813extern struct Scsi_Host *scsi_host_get(struct Scsi_Host *);
814extern void scsi_host_put(struct Scsi_Host *t);
815extern struct Scsi_Host *scsi_host_lookup(unsigned short);
816extern const char *scsi_host_state_name(enum scsi_host_state);
817extern void scsi_cmd_get_serial(struct Scsi_Host *, struct scsi_cmnd *);
818
819extern u64 scsi_calculate_bounce_limit(struct Scsi_Host *);
820
821static inline int __must_check scsi_add_host(struct Scsi_Host *host,
822 struct device *dev)
823{
824 return scsi_add_host_with_dma(host, dev, dev);
825}
826
827static inline struct device *scsi_get_device(struct Scsi_Host *shost)
828{
829 return shost->shost_gendev.parent;
830}
831
832/**
833 * scsi_host_scan_allowed - Is scanning of this host allowed
834 * @shost: Pointer to Scsi_Host.
835 **/
836static inline int scsi_host_scan_allowed(struct Scsi_Host *shost)
837{
838 return shost->shost_state == SHOST_RUNNING ||
839 shost->shost_state == SHOST_RECOVERY;
840}
841
842extern void scsi_unblock_requests(struct Scsi_Host *);
843extern void scsi_block_requests(struct Scsi_Host *);
844
845struct class_container;
846
847extern struct request_queue *__scsi_alloc_queue(struct Scsi_Host *shost,
848 void (*) (struct request_queue *));
849/*
850 * These two functions are used to allocate and free a pseudo device
851 * which will connect to the host adapter itself rather than any
852 * physical device. You must deallocate when you are done with the
853 * thing. This physical pseudo-device isn't real and won't be available
854 * from any high-level drivers.
855 */
856extern void scsi_free_host_dev(struct scsi_device *);
857extern struct scsi_device *scsi_get_host_dev(struct Scsi_Host *);
858
859/*
860 * DIF defines the exchange of protection information between
861 * initiator and SBC block device.
862 *
863 * DIX defines the exchange of protection information between OS and
864 * initiator.
865 */
866enum scsi_host_prot_capabilities {
867 SHOST_DIF_TYPE1_PROTECTION = 1 << 0, /* T10 DIF Type 1 */
868 SHOST_DIF_TYPE2_PROTECTION = 1 << 1, /* T10 DIF Type 2 */
869 SHOST_DIF_TYPE3_PROTECTION = 1 << 2, /* T10 DIF Type 3 */
870
871 SHOST_DIX_TYPE0_PROTECTION = 1 << 3, /* DIX between OS and HBA only */
872 SHOST_DIX_TYPE1_PROTECTION = 1 << 4, /* DIX with DIF Type 1 */
873 SHOST_DIX_TYPE2_PROTECTION = 1 << 5, /* DIX with DIF Type 2 */
874 SHOST_DIX_TYPE3_PROTECTION = 1 << 6, /* DIX with DIF Type 3 */
875};
876
877/*
878 * SCSI hosts which support the Data Integrity Extensions must
879 * indicate their capabilities by setting the prot_capabilities using
880 * this call.
881 */
882static inline void scsi_host_set_prot(struct Scsi_Host *shost, unsigned int mask)
883{
884 shost->prot_capabilities = mask;
885}
886
887static inline unsigned int scsi_host_get_prot(struct Scsi_Host *shost)
888{
889 return shost->prot_capabilities;
890}
891
892static inline int scsi_host_prot_dma(struct Scsi_Host *shost)
893{
894 return shost->prot_capabilities >= SHOST_DIX_TYPE0_PROTECTION;
895}
896
897static inline unsigned int scsi_host_dif_capable(struct Scsi_Host *shost, unsigned int target_type)
898{
899 static unsigned char cap[] = { 0,
900 SHOST_DIF_TYPE1_PROTECTION,
901 SHOST_DIF_TYPE2_PROTECTION,
902 SHOST_DIF_TYPE3_PROTECTION };
903
904 if (target_type >= ARRAY_SIZE(cap))
905 return 0;
906
907 return shost->prot_capabilities & cap[target_type] ? target_type : 0;
908}
909
910static inline unsigned int scsi_host_dix_capable(struct Scsi_Host *shost, unsigned int target_type)
911{
912#if defined(CONFIG_BLK_DEV_INTEGRITY)
913 static unsigned char cap[] = { SHOST_DIX_TYPE0_PROTECTION,
914 SHOST_DIX_TYPE1_PROTECTION,
915 SHOST_DIX_TYPE2_PROTECTION,
916 SHOST_DIX_TYPE3_PROTECTION };
917
918 if (target_type >= ARRAY_SIZE(cap))
919 return 0;
920
921 return shost->prot_capabilities & cap[target_type];
922#endif
923 return 0;
924}
925
926/*
927 * All DIX-capable initiators must support the T10-mandated CRC
928 * checksum. Controllers can optionally implement the IP checksum
929 * scheme which has much lower impact on system performance. Note
930 * that the main rationale for the checksum is to match integrity
931 * metadata with data. Detecting bit errors are a job for ECC memory
932 * and buses.
933 */
934
935enum scsi_host_guard_type {
936 SHOST_DIX_GUARD_CRC = 1 << 0,
937 SHOST_DIX_GUARD_IP = 1 << 1,
938};
939
940static inline void scsi_host_set_guard(struct Scsi_Host *shost, unsigned char type)
941{
942 shost->prot_guard_type = type;
943}
944
945static inline unsigned char scsi_host_get_guard(struct Scsi_Host *shost)
946{
947 return shost->prot_guard_type;
948}
949
950/* legacy interfaces */
951extern struct Scsi_Host *scsi_register(struct scsi_host_template *, int);
952extern void scsi_unregister(struct Scsi_Host *);
953extern int scsi_host_set_state(struct Scsi_Host *, enum scsi_host_state);
954
955#endif /* _SCSI_SCSI_HOST_H */