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1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef _SCSI_SCSI_HOST_H
3#define _SCSI_SCSI_HOST_H
4
5#include <linux/device.h>
6#include <linux/list.h>
7#include <linux/types.h>
8#include <linux/workqueue.h>
9#include <linux/mutex.h>
10#include <linux/seq_file.h>
11#include <linux/blk-mq.h>
12#include <scsi/scsi.h>
13
14struct block_device;
15struct completion;
16struct module;
17struct scsi_cmnd;
18struct scsi_device;
19struct scsi_host_cmd_pool;
20struct scsi_target;
21struct Scsi_Host;
22struct scsi_host_cmd_pool;
23struct scsi_transport_template;
24
25
26#define SG_ALL SG_CHUNK_SIZE
27
28#define MODE_UNKNOWN 0x00
29#define MODE_INITIATOR 0x01
30#define MODE_TARGET 0x02
31
32struct scsi_host_template {
33 struct module *module;
34 const char *name;
35
36 /*
37 * The info function will return whatever useful information the
38 * developer sees fit. If not provided, then the name field will
39 * be used instead.
40 *
41 * Status: OPTIONAL
42 */
43 const char *(* info)(struct Scsi_Host *);
44
45 /*
46 * Ioctl interface
47 *
48 * Status: OPTIONAL
49 */
50 int (*ioctl)(struct scsi_device *dev, unsigned int cmd,
51 void __user *arg);
52
53
54#ifdef CONFIG_COMPAT
55 /*
56 * Compat handler. Handle 32bit ABI.
57 * When unknown ioctl is passed return -ENOIOCTLCMD.
58 *
59 * Status: OPTIONAL
60 */
61 int (*compat_ioctl)(struct scsi_device *dev, unsigned int cmd,
62 void __user *arg);
63#endif
64
65 int (*init_cmd_priv)(struct Scsi_Host *shost, struct scsi_cmnd *cmd);
66 int (*exit_cmd_priv)(struct Scsi_Host *shost, struct scsi_cmnd *cmd);
67
68 /*
69 * The queuecommand function is used to queue up a scsi
70 * command block to the LLDD. When the driver finished
71 * processing the command the done callback is invoked.
72 *
73 * If queuecommand returns 0, then the driver has accepted the
74 * command. It must also push it to the HBA if the scsi_cmnd
75 * flag SCMD_LAST is set, or if the driver does not implement
76 * commit_rqs. The done() function must be called on the command
77 * when the driver has finished with it. (you may call done on the
78 * command before queuecommand returns, but in this case you
79 * *must* return 0 from queuecommand).
80 *
81 * Queuecommand may also reject the command, in which case it may
82 * not touch the command and must not call done() for it.
83 *
84 * There are two possible rejection returns:
85 *
86 * SCSI_MLQUEUE_DEVICE_BUSY: Block this device temporarily, but
87 * allow commands to other devices serviced by this host.
88 *
89 * SCSI_MLQUEUE_HOST_BUSY: Block all devices served by this
90 * host temporarily.
91 *
92 * For compatibility, any other non-zero return is treated the
93 * same as SCSI_MLQUEUE_HOST_BUSY.
94 *
95 * NOTE: "temporarily" means either until the next command for#
96 * this device/host completes, or a period of time determined by
97 * I/O pressure in the system if there are no other outstanding
98 * commands.
99 *
100 * STATUS: REQUIRED
101 */
102 int (* queuecommand)(struct Scsi_Host *, struct scsi_cmnd *);
103
104 /*
105 * The commit_rqs function is used to trigger a hardware
106 * doorbell after some requests have been queued with
107 * queuecommand, when an error is encountered before sending
108 * the request with SCMD_LAST set.
109 *
110 * STATUS: OPTIONAL
111 */
112 void (*commit_rqs)(struct Scsi_Host *, u16);
113
114 /*
115 * This is an error handling strategy routine. You don't need to
116 * define one of these if you don't want to - there is a default
117 * routine that is present that should work in most cases. For those
118 * driver authors that have the inclination and ability to write their
119 * own strategy routine, this is where it is specified. Note - the
120 * strategy routine is *ALWAYS* run in the context of the kernel eh
121 * thread. Thus you are guaranteed to *NOT* be in an interrupt
122 * handler when you execute this, and you are also guaranteed to
123 * *NOT* have any other commands being queued while you are in the
124 * strategy routine. When you return from this function, operations
125 * return to normal.
126 *
127 * See scsi_error.c scsi_unjam_host for additional comments about
128 * what this function should and should not be attempting to do.
129 *
130 * Status: REQUIRED (at least one of them)
131 */
132 int (* eh_abort_handler)(struct scsi_cmnd *);
133 int (* eh_device_reset_handler)(struct scsi_cmnd *);
134 int (* eh_target_reset_handler)(struct scsi_cmnd *);
135 int (* eh_bus_reset_handler)(struct scsi_cmnd *);
136 int (* eh_host_reset_handler)(struct scsi_cmnd *);
137
138 /*
139 * Before the mid layer attempts to scan for a new device where none
140 * currently exists, it will call this entry in your driver. Should
141 * your driver need to allocate any structs or perform any other init
142 * items in order to send commands to a currently unused target/lun
143 * combo, then this is where you can perform those allocations. This
144 * is specifically so that drivers won't have to perform any kind of
145 * "is this a new device" checks in their queuecommand routine,
146 * thereby making the hot path a bit quicker.
147 *
148 * Return values: 0 on success, non-0 on failure
149 *
150 * Deallocation: If we didn't find any devices at this ID, you will
151 * get an immediate call to slave_destroy(). If we find something
152 * here then you will get a call to slave_configure(), then the
153 * device will be used for however long it is kept around, then when
154 * the device is removed from the system (or * possibly at reboot
155 * time), you will then get a call to slave_destroy(). This is
156 * assuming you implement slave_configure and slave_destroy.
157 * However, if you allocate memory and hang it off the device struct,
158 * then you must implement the slave_destroy() routine at a minimum
159 * in order to avoid leaking memory
160 * each time a device is tore down.
161 *
162 * Status: OPTIONAL
163 */
164 int (* slave_alloc)(struct scsi_device *);
165
166 /*
167 * Once the device has responded to an INQUIRY and we know the
168 * device is online, we call into the low level driver with the
169 * struct scsi_device *. If the low level device driver implements
170 * this function, it *must* perform the task of setting the queue
171 * depth on the device. All other tasks are optional and depend
172 * on what the driver supports and various implementation details.
173 *
174 * Things currently recommended to be handled at this time include:
175 *
176 * 1. Setting the device queue depth. Proper setting of this is
177 * described in the comments for scsi_change_queue_depth.
178 * 2. Determining if the device supports the various synchronous
179 * negotiation protocols. The device struct will already have
180 * responded to INQUIRY and the results of the standard items
181 * will have been shoved into the various device flag bits, eg.
182 * device->sdtr will be true if the device supports SDTR messages.
183 * 3. Allocating command structs that the device will need.
184 * 4. Setting the default timeout on this device (if needed).
185 * 5. Anything else the low level driver might want to do on a device
186 * specific setup basis...
187 * 6. Return 0 on success, non-0 on error. The device will be marked
188 * as offline on error so that no access will occur. If you return
189 * non-0, your slave_destroy routine will never get called for this
190 * device, so don't leave any loose memory hanging around, clean
191 * up after yourself before returning non-0
192 *
193 * Status: OPTIONAL
194 */
195 int (* slave_configure)(struct scsi_device *);
196
197 /*
198 * Immediately prior to deallocating the device and after all activity
199 * has ceased the mid layer calls this point so that the low level
200 * driver may completely detach itself from the scsi device and vice
201 * versa. The low level driver is responsible for freeing any memory
202 * it allocated in the slave_alloc or slave_configure calls.
203 *
204 * Status: OPTIONAL
205 */
206 void (* slave_destroy)(struct scsi_device *);
207
208 /*
209 * Before the mid layer attempts to scan for a new device attached
210 * to a target where no target currently exists, it will call this
211 * entry in your driver. Should your driver need to allocate any
212 * structs or perform any other init items in order to send commands
213 * to a currently unused target, then this is where you can perform
214 * those allocations.
215 *
216 * Return values: 0 on success, non-0 on failure
217 *
218 * Status: OPTIONAL
219 */
220 int (* target_alloc)(struct scsi_target *);
221
222 /*
223 * Immediately prior to deallocating the target structure, and
224 * after all activity to attached scsi devices has ceased, the
225 * midlayer calls this point so that the driver may deallocate
226 * and terminate any references to the target.
227 *
228 * Status: OPTIONAL
229 */
230 void (* target_destroy)(struct scsi_target *);
231
232 /*
233 * If a host has the ability to discover targets on its own instead
234 * of scanning the entire bus, it can fill in this function and
235 * call scsi_scan_host(). This function will be called periodically
236 * until it returns 1 with the scsi_host and the elapsed time of
237 * the scan in jiffies.
238 *
239 * Status: OPTIONAL
240 */
241 int (* scan_finished)(struct Scsi_Host *, unsigned long);
242
243 /*
244 * If the host wants to be called before the scan starts, but
245 * after the midlayer has set up ready for the scan, it can fill
246 * in this function.
247 *
248 * Status: OPTIONAL
249 */
250 void (* scan_start)(struct Scsi_Host *);
251
252 /*
253 * Fill in this function to allow the queue depth of this host
254 * to be changeable (on a per device basis). Returns either
255 * the current queue depth setting (may be different from what
256 * was passed in) or an error. An error should only be
257 * returned if the requested depth is legal but the driver was
258 * unable to set it. If the requested depth is illegal, the
259 * driver should set and return the closest legal queue depth.
260 *
261 * Status: OPTIONAL
262 */
263 int (* change_queue_depth)(struct scsi_device *, int);
264
265 /*
266 * This functions lets the driver expose the queue mapping
267 * to the block layer.
268 *
269 * Status: OPTIONAL
270 */
271 int (* map_queues)(struct Scsi_Host *shost);
272
273 /*
274 * Check if scatterlists need to be padded for DMA draining.
275 *
276 * Status: OPTIONAL
277 */
278 bool (* dma_need_drain)(struct request *rq);
279
280 /*
281 * This function determines the BIOS parameters for a given
282 * harddisk. These tend to be numbers that are made up by
283 * the host adapter. Parameters:
284 * size, device, list (heads, sectors, cylinders)
285 *
286 * Status: OPTIONAL
287 */
288 int (* bios_param)(struct scsi_device *, struct block_device *,
289 sector_t, int []);
290
291 /*
292 * This function is called when one or more partitions on the
293 * device reach beyond the end of the device.
294 *
295 * Status: OPTIONAL
296 */
297 void (*unlock_native_capacity)(struct scsi_device *);
298
299 /*
300 * Can be used to export driver statistics and other infos to the
301 * world outside the kernel ie. userspace and it also provides an
302 * interface to feed the driver with information.
303 *
304 * Status: OBSOLETE
305 */
306 int (*show_info)(struct seq_file *, struct Scsi_Host *);
307 int (*write_info)(struct Scsi_Host *, char *, int);
308
309 /*
310 * This is an optional routine that allows the transport to become
311 * involved when a scsi io timer fires. The return value tells the
312 * timer routine how to finish the io timeout handling.
313 *
314 * Status: OPTIONAL
315 */
316 enum blk_eh_timer_return (*eh_timed_out)(struct scsi_cmnd *);
317
318 /* This is an optional routine that allows transport to initiate
319 * LLD adapter or firmware reset using sysfs attribute.
320 *
321 * Return values: 0 on success, -ve value on failure.
322 *
323 * Status: OPTIONAL
324 */
325
326 int (*host_reset)(struct Scsi_Host *shost, int reset_type);
327#define SCSI_ADAPTER_RESET 1
328#define SCSI_FIRMWARE_RESET 2
329
330
331 /*
332 * Name of proc directory
333 */
334 const char *proc_name;
335
336 /*
337 * Used to store the procfs directory if a driver implements the
338 * show_info method.
339 */
340 struct proc_dir_entry *proc_dir;
341
342 /*
343 * This determines if we will use a non-interrupt driven
344 * or an interrupt driven scheme. It is set to the maximum number
345 * of simultaneous commands a single hw queue in HBA will accept.
346 */
347 int can_queue;
348
349 /*
350 * In many instances, especially where disconnect / reconnect are
351 * supported, our host also has an ID on the SCSI bus. If this is
352 * the case, then it must be reserved. Please set this_id to -1 if
353 * your setup is in single initiator mode, and the host lacks an
354 * ID.
355 */
356 int this_id;
357
358 /*
359 * This determines the degree to which the host adapter is capable
360 * of scatter-gather.
361 */
362 unsigned short sg_tablesize;
363 unsigned short sg_prot_tablesize;
364
365 /*
366 * Set this if the host adapter has limitations beside segment count.
367 */
368 unsigned int max_sectors;
369
370 /*
371 * Maximum size in bytes of a single segment.
372 */
373 unsigned int max_segment_size;
374
375 /*
376 * DMA scatter gather segment boundary limit. A segment crossing this
377 * boundary will be split in two.
378 */
379 unsigned long dma_boundary;
380
381 unsigned long virt_boundary_mask;
382
383 /*
384 * This specifies "machine infinity" for host templates which don't
385 * limit the transfer size. Note this limit represents an absolute
386 * maximum, and may be over the transfer limits allowed for
387 * individual devices (e.g. 256 for SCSI-1).
388 */
389#define SCSI_DEFAULT_MAX_SECTORS 1024
390
391 /*
392 * True if this host adapter can make good use of linked commands.
393 * This will allow more than one command to be queued to a given
394 * unit on a given host. Set this to the maximum number of command
395 * blocks to be provided for each device. Set this to 1 for one
396 * command block per lun, 2 for two, etc. Do not set this to 0.
397 * You should make sure that the host adapter will do the right thing
398 * before you try setting this above 1.
399 */
400 short cmd_per_lun;
401
402 /*
403 * present contains counter indicating how many boards of this
404 * type were found when we did the scan.
405 */
406 unsigned char present;
407
408 /* If use block layer to manage tags, this is tag allocation policy */
409 int tag_alloc_policy;
410
411 /*
412 * Track QUEUE_FULL events and reduce queue depth on demand.
413 */
414 unsigned track_queue_depth:1;
415
416 /*
417 * This specifies the mode that a LLD supports.
418 */
419 unsigned supported_mode:2;
420
421 /*
422 * True if this host adapter uses unchecked DMA onto an ISA bus.
423 */
424 unsigned unchecked_isa_dma:1;
425
426 /*
427 * True for emulated SCSI host adapters (e.g. ATAPI).
428 */
429 unsigned emulated:1;
430
431 /*
432 * True if the low-level driver performs its own reset-settle delays.
433 */
434 unsigned skip_settle_delay:1;
435
436 /* True if the controller does not support WRITE SAME */
437 unsigned no_write_same:1;
438
439 /*
440 * Countdown for host blocking with no commands outstanding.
441 */
442 unsigned int max_host_blocked;
443
444 /*
445 * Default value for the blocking. If the queue is empty,
446 * host_blocked counts down in the request_fn until it restarts
447 * host operations as zero is reached.
448 *
449 * FIXME: This should probably be a value in the template
450 */
451#define SCSI_DEFAULT_HOST_BLOCKED 7
452
453 /*
454 * Pointer to the sysfs class properties for this host, NULL terminated.
455 */
456 struct device_attribute **shost_attrs;
457
458 /*
459 * Pointer to the SCSI device properties for this host, NULL terminated.
460 */
461 struct device_attribute **sdev_attrs;
462
463 /*
464 * Pointer to the SCSI device attribute groups for this host,
465 * NULL terminated.
466 */
467 const struct attribute_group **sdev_groups;
468
469 /*
470 * Vendor Identifier associated with the host
471 *
472 * Note: When specifying vendor_id, be sure to read the
473 * Vendor Type and ID formatting requirements specified in
474 * scsi_netlink.h
475 */
476 u64 vendor_id;
477
478 /*
479 * Additional per-command data allocated for the driver.
480 */
481 unsigned int cmd_size;
482 struct scsi_host_cmd_pool *cmd_pool;
483
484 /* Delay for runtime autosuspend */
485 int rpm_autosuspend_delay;
486};
487
488/*
489 * Temporary #define for host lock push down. Can be removed when all
490 * drivers have been updated to take advantage of unlocked
491 * queuecommand.
492 *
493 */
494#define DEF_SCSI_QCMD(func_name) \
495 int func_name(struct Scsi_Host *shost, struct scsi_cmnd *cmd) \
496 { \
497 unsigned long irq_flags; \
498 int rc; \
499 spin_lock_irqsave(shost->host_lock, irq_flags); \
500 rc = func_name##_lck (cmd, cmd->scsi_done); \
501 spin_unlock_irqrestore(shost->host_lock, irq_flags); \
502 return rc; \
503 }
504
505
506/*
507 * shost state: If you alter this, you also need to alter scsi_sysfs.c
508 * (for the ascii descriptions) and the state model enforcer:
509 * scsi_host_set_state()
510 */
511enum scsi_host_state {
512 SHOST_CREATED = 1,
513 SHOST_RUNNING,
514 SHOST_CANCEL,
515 SHOST_DEL,
516 SHOST_RECOVERY,
517 SHOST_CANCEL_RECOVERY,
518 SHOST_DEL_RECOVERY,
519};
520
521struct Scsi_Host {
522 /*
523 * __devices is protected by the host_lock, but you should
524 * usually use scsi_device_lookup / shost_for_each_device
525 * to access it and don't care about locking yourself.
526 * In the rare case of being in irq context you can use
527 * their __ prefixed variants with the lock held. NEVER
528 * access this list directly from a driver.
529 */
530 struct list_head __devices;
531 struct list_head __targets;
532
533 struct list_head starved_list;
534
535 spinlock_t default_lock;
536 spinlock_t *host_lock;
537
538 struct mutex scan_mutex;/* serialize scanning activity */
539
540 struct list_head eh_cmd_q;
541 struct task_struct * ehandler; /* Error recovery thread. */
542 struct completion * eh_action; /* Wait for specific actions on the
543 host. */
544 wait_queue_head_t host_wait;
545 struct scsi_host_template *hostt;
546 struct scsi_transport_template *transportt;
547
548 /* Area to keep a shared tag map */
549 struct blk_mq_tag_set tag_set;
550
551 atomic_t host_blocked;
552
553 unsigned int host_failed; /* commands that failed.
554 protected by host_lock */
555 unsigned int host_eh_scheduled; /* EH scheduled without command */
556
557 unsigned int host_no; /* Used for IOCTL_GET_IDLUN, /proc/scsi et al. */
558
559 /* next two fields are used to bound the time spent in error handling */
560 int eh_deadline;
561 unsigned long last_reset;
562
563
564 /*
565 * These three parameters can be used to allow for wide scsi,
566 * and for host adapters that support multiple busses
567 * The last two should be set to 1 more than the actual max id
568 * or lun (e.g. 8 for SCSI parallel systems).
569 */
570 unsigned int max_channel;
571 unsigned int max_id;
572 u64 max_lun;
573
574 /*
575 * This is a unique identifier that must be assigned so that we
576 * have some way of identifying each detected host adapter properly
577 * and uniquely. For hosts that do not support more than one card
578 * in the system at one time, this does not need to be set. It is
579 * initialized to 0 in scsi_register.
580 */
581 unsigned int unique_id;
582
583 /*
584 * The maximum length of SCSI commands that this host can accept.
585 * Probably 12 for most host adapters, but could be 16 for others.
586 * or 260 if the driver supports variable length cdbs.
587 * For drivers that don't set this field, a value of 12 is
588 * assumed.
589 */
590 unsigned short max_cmd_len;
591
592 int this_id;
593 int can_queue;
594 short cmd_per_lun;
595 short unsigned int sg_tablesize;
596 short unsigned int sg_prot_tablesize;
597 unsigned int max_sectors;
598 unsigned int max_segment_size;
599 unsigned long dma_boundary;
600 unsigned long virt_boundary_mask;
601 /*
602 * In scsi-mq mode, the number of hardware queues supported by the LLD.
603 *
604 * Note: it is assumed that each hardware queue has a queue depth of
605 * can_queue. In other words, the total queue depth per host
606 * is nr_hw_queues * can_queue.
607 */
608 unsigned nr_hw_queues;
609 unsigned active_mode:2;
610 unsigned unchecked_isa_dma:1;
611
612 /*
613 * Host has requested that no further requests come through for the
614 * time being.
615 */
616 unsigned host_self_blocked:1;
617
618 /*
619 * Host uses correct SCSI ordering not PC ordering. The bit is
620 * set for the minority of drivers whose authors actually read
621 * the spec ;).
622 */
623 unsigned reverse_ordering:1;
624
625 /* Task mgmt function in progress */
626 unsigned tmf_in_progress:1;
627
628 /* Asynchronous scan in progress */
629 unsigned async_scan:1;
630
631 /* Don't resume host in EH */
632 unsigned eh_noresume:1;
633
634 /* The controller does not support WRITE SAME */
635 unsigned no_write_same:1;
636
637 /* Host responded with short (<36 bytes) INQUIRY result */
638 unsigned short_inquiry:1;
639
640 /* The transport requires the LUN bits NOT to be stored in CDB[1] */
641 unsigned no_scsi2_lun_in_cdb:1;
642
643 /*
644 * Optional work queue to be utilized by the transport
645 */
646 char work_q_name[20];
647 struct workqueue_struct *work_q;
648
649 /*
650 * Task management function work queue
651 */
652 struct workqueue_struct *tmf_work_q;
653
654 /*
655 * Value host_blocked counts down from
656 */
657 unsigned int max_host_blocked;
658
659 /* Protection Information */
660 unsigned int prot_capabilities;
661 unsigned char prot_guard_type;
662
663 /* legacy crap */
664 unsigned long base;
665 unsigned long io_port;
666 unsigned char n_io_port;
667 unsigned char dma_channel;
668 unsigned int irq;
669
670
671 enum scsi_host_state shost_state;
672
673 /* ldm bits */
674 struct device shost_gendev, shost_dev;
675
676 /*
677 * Points to the transport data (if any) which is allocated
678 * separately
679 */
680 void *shost_data;
681
682 /*
683 * Points to the physical bus device we'd use to do DMA
684 * Needed just in case we have virtual hosts.
685 */
686 struct device *dma_dev;
687
688 /*
689 * We should ensure that this is aligned, both for better performance
690 * and also because some compilers (m68k) don't automatically force
691 * alignment to a long boundary.
692 */
693 unsigned long hostdata[] /* Used for storage of host specific stuff */
694 __attribute__ ((aligned (sizeof(unsigned long))));
695};
696
697#define class_to_shost(d) \
698 container_of(d, struct Scsi_Host, shost_dev)
699
700#define shost_printk(prefix, shost, fmt, a...) \
701 dev_printk(prefix, &(shost)->shost_gendev, fmt, ##a)
702
703static inline void *shost_priv(struct Scsi_Host *shost)
704{
705 return (void *)shost->hostdata;
706}
707
708int scsi_is_host_device(const struct device *);
709
710static inline struct Scsi_Host *dev_to_shost(struct device *dev)
711{
712 while (!scsi_is_host_device(dev)) {
713 if (!dev->parent)
714 return NULL;
715 dev = dev->parent;
716 }
717 return container_of(dev, struct Scsi_Host, shost_gendev);
718}
719
720static inline int scsi_host_in_recovery(struct Scsi_Host *shost)
721{
722 return shost->shost_state == SHOST_RECOVERY ||
723 shost->shost_state == SHOST_CANCEL_RECOVERY ||
724 shost->shost_state == SHOST_DEL_RECOVERY ||
725 shost->tmf_in_progress;
726}
727
728extern int scsi_queue_work(struct Scsi_Host *, struct work_struct *);
729extern void scsi_flush_work(struct Scsi_Host *);
730
731extern struct Scsi_Host *scsi_host_alloc(struct scsi_host_template *, int);
732extern int __must_check scsi_add_host_with_dma(struct Scsi_Host *,
733 struct device *,
734 struct device *);
735extern void scsi_scan_host(struct Scsi_Host *);
736extern void scsi_rescan_device(struct device *);
737extern void scsi_remove_host(struct Scsi_Host *);
738extern struct Scsi_Host *scsi_host_get(struct Scsi_Host *);
739extern int scsi_host_busy(struct Scsi_Host *shost);
740extern void scsi_host_put(struct Scsi_Host *t);
741extern struct Scsi_Host *scsi_host_lookup(unsigned short);
742extern const char *scsi_host_state_name(enum scsi_host_state);
743extern void scsi_host_complete_all_commands(struct Scsi_Host *shost,
744 int status);
745
746static inline int __must_check scsi_add_host(struct Scsi_Host *host,
747 struct device *dev)
748{
749 return scsi_add_host_with_dma(host, dev, dev);
750}
751
752static inline struct device *scsi_get_device(struct Scsi_Host *shost)
753{
754 return shost->shost_gendev.parent;
755}
756
757/**
758 * scsi_host_scan_allowed - Is scanning of this host allowed
759 * @shost: Pointer to Scsi_Host.
760 **/
761static inline int scsi_host_scan_allowed(struct Scsi_Host *shost)
762{
763 return shost->shost_state == SHOST_RUNNING ||
764 shost->shost_state == SHOST_RECOVERY;
765}
766
767extern void scsi_unblock_requests(struct Scsi_Host *);
768extern void scsi_block_requests(struct Scsi_Host *);
769extern int scsi_host_block(struct Scsi_Host *shost);
770extern int scsi_host_unblock(struct Scsi_Host *shost, int new_state);
771
772void scsi_host_busy_iter(struct Scsi_Host *,
773 bool (*fn)(struct scsi_cmnd *, void *, bool), void *priv);
774
775struct class_container;
776
777/*
778 * These two functions are used to allocate and free a pseudo device
779 * which will connect to the host adapter itself rather than any
780 * physical device. You must deallocate when you are done with the
781 * thing. This physical pseudo-device isn't real and won't be available
782 * from any high-level drivers.
783 */
784extern void scsi_free_host_dev(struct scsi_device *);
785extern struct scsi_device *scsi_get_host_dev(struct Scsi_Host *);
786
787/*
788 * DIF defines the exchange of protection information between
789 * initiator and SBC block device.
790 *
791 * DIX defines the exchange of protection information between OS and
792 * initiator.
793 */
794enum scsi_host_prot_capabilities {
795 SHOST_DIF_TYPE1_PROTECTION = 1 << 0, /* T10 DIF Type 1 */
796 SHOST_DIF_TYPE2_PROTECTION = 1 << 1, /* T10 DIF Type 2 */
797 SHOST_DIF_TYPE3_PROTECTION = 1 << 2, /* T10 DIF Type 3 */
798
799 SHOST_DIX_TYPE0_PROTECTION = 1 << 3, /* DIX between OS and HBA only */
800 SHOST_DIX_TYPE1_PROTECTION = 1 << 4, /* DIX with DIF Type 1 */
801 SHOST_DIX_TYPE2_PROTECTION = 1 << 5, /* DIX with DIF Type 2 */
802 SHOST_DIX_TYPE3_PROTECTION = 1 << 6, /* DIX with DIF Type 3 */
803};
804
805/*
806 * SCSI hosts which support the Data Integrity Extensions must
807 * indicate their capabilities by setting the prot_capabilities using
808 * this call.
809 */
810static inline void scsi_host_set_prot(struct Scsi_Host *shost, unsigned int mask)
811{
812 shost->prot_capabilities = mask;
813}
814
815static inline unsigned int scsi_host_get_prot(struct Scsi_Host *shost)
816{
817 return shost->prot_capabilities;
818}
819
820static inline int scsi_host_prot_dma(struct Scsi_Host *shost)
821{
822 return shost->prot_capabilities >= SHOST_DIX_TYPE0_PROTECTION;
823}
824
825static inline unsigned int scsi_host_dif_capable(struct Scsi_Host *shost, unsigned int target_type)
826{
827 static unsigned char cap[] = { 0,
828 SHOST_DIF_TYPE1_PROTECTION,
829 SHOST_DIF_TYPE2_PROTECTION,
830 SHOST_DIF_TYPE3_PROTECTION };
831
832 if (target_type >= ARRAY_SIZE(cap))
833 return 0;
834
835 return shost->prot_capabilities & cap[target_type] ? target_type : 0;
836}
837
838static inline unsigned int scsi_host_dix_capable(struct Scsi_Host *shost, unsigned int target_type)
839{
840#if defined(CONFIG_BLK_DEV_INTEGRITY)
841 static unsigned char cap[] = { SHOST_DIX_TYPE0_PROTECTION,
842 SHOST_DIX_TYPE1_PROTECTION,
843 SHOST_DIX_TYPE2_PROTECTION,
844 SHOST_DIX_TYPE3_PROTECTION };
845
846 if (target_type >= ARRAY_SIZE(cap))
847 return 0;
848
849 return shost->prot_capabilities & cap[target_type];
850#endif
851 return 0;
852}
853
854/*
855 * All DIX-capable initiators must support the T10-mandated CRC
856 * checksum. Controllers can optionally implement the IP checksum
857 * scheme which has much lower impact on system performance. Note
858 * that the main rationale for the checksum is to match integrity
859 * metadata with data. Detecting bit errors are a job for ECC memory
860 * and buses.
861 */
862
863enum scsi_host_guard_type {
864 SHOST_DIX_GUARD_CRC = 1 << 0,
865 SHOST_DIX_GUARD_IP = 1 << 1,
866};
867
868static inline void scsi_host_set_guard(struct Scsi_Host *shost, unsigned char type)
869{
870 shost->prot_guard_type = type;
871}
872
873static inline unsigned char scsi_host_get_guard(struct Scsi_Host *shost)
874{
875 return shost->prot_guard_type;
876}
877
878extern int scsi_host_set_state(struct Scsi_Host *, enum scsi_host_state);
879
880#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 */