1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _SCSI_SCSI_HOST_H
3 #define _SCSI_SCSI_HOST_H
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>
19 struct scsi_host_cmd_pool;
22 struct scsi_host_cmd_pool;
23 struct scsi_transport_template;
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
35 * Anything else: Indicates the maximum number of chains that can be
36 * used in one scatter-gather request.
39 #define SG_ALL SG_CHUNK_SIZE
41 #define MODE_UNKNOWN 0x00
42 #define MODE_INITIATOR 0x01
43 #define MODE_TARGET 0x02
45 struct scsi_host_template {
46 struct module *module;
50 * The info function will return whatever useful information the
51 * developer sees fit. If not provided, then the name field will
56 const char *(* info)(struct Scsi_Host *);
63 int (* ioctl)(struct scsi_device *dev, int cmd, void __user *arg);
68 * Compat handler. Handle 32bit ABI.
69 * When unknown ioctl is passed return -ENOIOCTLCMD.
73 int (* compat_ioctl)(struct scsi_device *dev, int cmd, void __user *arg);
77 * The queuecommand function is used to queue up a scsi
78 * command block to the LLDD. When the driver finished
79 * processing the command the done callback is invoked.
81 * If queuecommand returns 0, then the HBA has accepted the
82 * command. The done() function must be called on the command
83 * when the driver has finished with it. (you may call done on the
84 * command before queuecommand returns, but in this case you
85 * *must* return 0 from queuecommand).
87 * Queuecommand may also reject the command, in which case it may
88 * not touch the command and must not call done() for it.
90 * There are two possible rejection returns:
92 * SCSI_MLQUEUE_DEVICE_BUSY: Block this device temporarily, but
93 * allow commands to other devices serviced by this host.
95 * SCSI_MLQUEUE_HOST_BUSY: Block all devices served by this
98 * For compatibility, any other non-zero return is treated the
99 * same as SCSI_MLQUEUE_HOST_BUSY.
101 * NOTE: "temporarily" means either until the next command for#
102 * this device/host completes, or a period of time determined by
103 * I/O pressure in the system if there are no other outstanding
108 int (* queuecommand)(struct Scsi_Host *, struct scsi_cmnd *);
111 * This is an error handling strategy routine. You don't need to
112 * define one of these if you don't want to - there is a default
113 * routine that is present that should work in most cases. For those
114 * driver authors that have the inclination and ability to write their
115 * own strategy routine, this is where it is specified. Note - the
116 * strategy routine is *ALWAYS* run in the context of the kernel eh
117 * thread. Thus you are guaranteed to *NOT* be in an interrupt
118 * handler when you execute this, and you are also guaranteed to
119 * *NOT* have any other commands being queued while you are in the
120 * strategy routine. When you return from this function, operations
123 * See scsi_error.c scsi_unjam_host for additional comments about
124 * what this function should and should not be attempting to do.
126 * Status: REQUIRED (at least one of them)
128 int (* eh_abort_handler)(struct scsi_cmnd *);
129 int (* eh_device_reset_handler)(struct scsi_cmnd *);
130 int (* eh_target_reset_handler)(struct scsi_cmnd *);
131 int (* eh_bus_reset_handler)(struct scsi_cmnd *);
132 int (* eh_host_reset_handler)(struct scsi_cmnd *);
135 * Before the mid layer attempts to scan for a new device where none
136 * currently exists, it will call this entry in your driver. Should
137 * your driver need to allocate any structs or perform any other init
138 * items in order to send commands to a currently unused target/lun
139 * combo, then this is where you can perform those allocations. This
140 * is specifically so that drivers won't have to perform any kind of
141 * "is this a new device" checks in their queuecommand routine,
142 * thereby making the hot path a bit quicker.
144 * Return values: 0 on success, non-0 on failure
146 * Deallocation: If we didn't find any devices at this ID, you will
147 * get an immediate call to slave_destroy(). If we find something
148 * here then you will get a call to slave_configure(), then the
149 * device will be used for however long it is kept around, then when
150 * the device is removed from the system (or * possibly at reboot
151 * time), you will then get a call to slave_destroy(). This is
152 * assuming you implement slave_configure and slave_destroy.
153 * However, if you allocate memory and hang it off the device struct,
154 * then you must implement the slave_destroy() routine at a minimum
155 * in order to avoid leaking memory
156 * each time a device is tore down.
160 int (* slave_alloc)(struct scsi_device *);
163 * Once the device has responded to an INQUIRY and we know the
164 * device is online, we call into the low level driver with the
165 * struct scsi_device *. If the low level device driver implements
166 * this function, it *must* perform the task of setting the queue
167 * depth on the device. All other tasks are optional and depend
168 * on what the driver supports and various implementation details.
170 * Things currently recommended to be handled at this time include:
172 * 1. Setting the device queue depth. Proper setting of this is
173 * described in the comments for scsi_change_queue_depth.
174 * 2. Determining if the device supports the various synchronous
175 * negotiation protocols. The device struct will already have
176 * responded to INQUIRY and the results of the standard items
177 * will have been shoved into the various device flag bits, eg.
178 * device->sdtr will be true if the device supports SDTR messages.
179 * 3. Allocating command structs that the device will need.
180 * 4. Setting the default timeout on this device (if needed).
181 * 5. Anything else the low level driver might want to do on a device
182 * specific setup basis...
183 * 6. Return 0 on success, non-0 on error. The device will be marked
184 * as offline on error so that no access will occur. If you return
185 * non-0, your slave_destroy routine will never get called for this
186 * device, so don't leave any loose memory hanging around, clean
187 * up after yourself before returning non-0
191 int (* slave_configure)(struct scsi_device *);
194 * Immediately prior to deallocating the device and after all activity
195 * has ceased the mid layer calls this point so that the low level
196 * driver may completely detach itself from the scsi device and vice
197 * versa. The low level driver is responsible for freeing any memory
198 * it allocated in the slave_alloc or slave_configure calls.
202 void (* slave_destroy)(struct scsi_device *);
205 * Before the mid layer attempts to scan for a new device attached
206 * to a target where no target currently exists, it will call this
207 * entry in your driver. Should your driver need to allocate any
208 * structs or perform any other init items in order to send commands
209 * to a currently unused target, then this is where you can perform
212 * Return values: 0 on success, non-0 on failure
216 int (* target_alloc)(struct scsi_target *);
219 * Immediately prior to deallocating the target structure, and
220 * after all activity to attached scsi devices has ceased, the
221 * midlayer calls this point so that the driver may deallocate
222 * and terminate any references to the target.
226 void (* target_destroy)(struct scsi_target *);
229 * If a host has the ability to discover targets on its own instead
230 * of scanning the entire bus, it can fill in this function and
231 * call scsi_scan_host(). This function will be called periodically
232 * until it returns 1 with the scsi_host and the elapsed time of
233 * the scan in jiffies.
237 int (* scan_finished)(struct Scsi_Host *, unsigned long);
240 * If the host wants to be called before the scan starts, but
241 * after the midlayer has set up ready for the scan, it can fill
246 void (* scan_start)(struct Scsi_Host *);
249 * Fill in this function to allow the queue depth of this host
250 * to be changeable (on a per device basis). Returns either
251 * the current queue depth setting (may be different from what
252 * was passed in) or an error. An error should only be
253 * returned if the requested depth is legal but the driver was
254 * unable to set it. If the requested depth is illegal, the
255 * driver should set and return the closest legal queue depth.
259 int (* change_queue_depth)(struct scsi_device *, int);
262 * This functions lets the driver expose the queue mapping
263 * to the block layer.
267 int (* map_queues)(struct Scsi_Host *shost);
270 * This function determines the BIOS parameters for a given
271 * harddisk. These tend to be numbers that are made up by
272 * the host adapter. Parameters:
273 * size, device, list (heads, sectors, cylinders)
277 int (* bios_param)(struct scsi_device *, struct block_device *,
281 * This function is called when one or more partitions on the
282 * device reach beyond the end of the device.
286 void (*unlock_native_capacity)(struct scsi_device *);
289 * Can be used to export driver statistics and other infos to the
290 * world outside the kernel ie. userspace and it also provides an
291 * interface to feed the driver with information.
295 int (*show_info)(struct seq_file *, struct Scsi_Host *);
296 int (*write_info)(struct Scsi_Host *, char *, int);
299 * This is an optional routine that allows the transport to become
300 * involved when a scsi io timer fires. The return value tells the
301 * timer routine how to finish the io timeout handling:
302 * EH_HANDLED: I fixed the error, please complete the command
303 * EH_RESET_TIMER: I need more time, reset the timer and
304 * begin counting again
305 * EH_DONE: Begin normal error recovery
309 enum blk_eh_timer_return (*eh_timed_out)(struct scsi_cmnd *);
311 /* This is an optional routine that allows transport to initiate
312 * LLD adapter or firmware reset using sysfs attribute.
314 * Return values: 0 on success, -ve value on failure.
319 int (*host_reset)(struct Scsi_Host *shost, int reset_type);
320 #define SCSI_ADAPTER_RESET 1
321 #define SCSI_FIRMWARE_RESET 2
325 * Name of proc directory
327 const char *proc_name;
330 * Used to store the procfs directory if a driver implements the
333 struct proc_dir_entry *proc_dir;
336 * This determines if we will use a non-interrupt driven
337 * or an interrupt driven scheme. It is set to the maximum number
338 * of simultaneous commands a given host adapter will accept.
343 * In many instances, especially where disconnect / reconnect are
344 * supported, our host also has an ID on the SCSI bus. If this is
345 * the case, then it must be reserved. Please set this_id to -1 if
346 * your setup is in single initiator mode, and the host lacks an
352 * This determines the degree to which the host adapter is capable
355 unsigned short sg_tablesize;
356 unsigned short sg_prot_tablesize;
359 * Set this if the host adapter has limitations beside segment count.
361 unsigned int max_sectors;
364 * Maximum size in bytes of a single segment.
366 unsigned int max_segment_size;
369 * DMA scatter gather segment boundary limit. A segment crossing this
370 * boundary will be split in two.
372 unsigned long dma_boundary;
375 * This specifies "machine infinity" for host templates which don't
376 * limit the transfer size. Note this limit represents an absolute
377 * maximum, and may be over the transfer limits allowed for
378 * individual devices (e.g. 256 for SCSI-1).
380 #define SCSI_DEFAULT_MAX_SECTORS 1024
383 * True if this host adapter can make good use of linked commands.
384 * This will allow more than one command to be queued to a given
385 * unit on a given host. Set this to the maximum number of command
386 * blocks to be provided for each device. Set this to 1 for one
387 * command block per lun, 2 for two, etc. Do not set this to 0.
388 * You should make sure that the host adapter will do the right thing
389 * before you try setting this above 1.
394 * present contains counter indicating how many boards of this
395 * type were found when we did the scan.
397 unsigned char present;
399 /* If use block layer to manage tags, this is tag allocation policy */
400 int tag_alloc_policy;
403 * Track QUEUE_FULL events and reduce queue depth on demand.
405 unsigned track_queue_depth:1;
408 * This specifies the mode that a LLD supports.
410 unsigned supported_mode:2;
413 * True if this host adapter uses unchecked DMA onto an ISA bus.
415 unsigned unchecked_isa_dma:1;
418 * True for emulated SCSI host adapters (e.g. ATAPI).
423 * True if the low-level driver performs its own reset-settle delays.
425 unsigned skip_settle_delay:1;
427 /* True if the controller does not support WRITE SAME */
428 unsigned no_write_same:1;
430 /* True if the low-level driver supports blk-mq only */
431 unsigned force_blk_mq:1;
434 * Countdown for host blocking with no commands outstanding.
436 unsigned int max_host_blocked;
439 * Default value for the blocking. If the queue is empty,
440 * host_blocked counts down in the request_fn until it restarts
441 * host operations as zero is reached.
443 * FIXME: This should probably be a value in the template
445 #define SCSI_DEFAULT_HOST_BLOCKED 7
448 * Pointer to the sysfs class properties for this host, NULL terminated.
450 struct device_attribute **shost_attrs;
453 * Pointer to the SCSI device properties for this host, NULL terminated.
455 struct device_attribute **sdev_attrs;
458 * Pointer to the SCSI device attribute groups for this host,
461 const struct attribute_group **sdev_groups;
464 * Vendor Identifier associated with the host
466 * Note: When specifying vendor_id, be sure to read the
467 * Vendor Type and ID formatting requirements specified in
473 * Additional per-command data allocated for the driver.
475 unsigned int cmd_size;
476 struct scsi_host_cmd_pool *cmd_pool;
480 * Temporary #define for host lock push down. Can be removed when all
481 * drivers have been updated to take advantage of unlocked
485 #define DEF_SCSI_QCMD(func_name) \
486 int func_name(struct Scsi_Host *shost, struct scsi_cmnd *cmd) \
488 unsigned long irq_flags; \
490 spin_lock_irqsave(shost->host_lock, irq_flags); \
491 scsi_cmd_get_serial(shost, cmd); \
492 rc = func_name##_lck (cmd, cmd->scsi_done); \
493 spin_unlock_irqrestore(shost->host_lock, irq_flags); \
499 * shost state: If you alter this, you also need to alter scsi_sysfs.c
500 * (for the ascii descriptions) and the state model enforcer:
501 * scsi_host_set_state()
503 enum scsi_host_state {
509 SHOST_CANCEL_RECOVERY,
515 * __devices is protected by the host_lock, but you should
516 * usually use scsi_device_lookup / shost_for_each_device
517 * to access it and don't care about locking yourself.
518 * In the rare case of being in irq context you can use
519 * their __ prefixed variants with the lock held. NEVER
520 * access this list directly from a driver.
522 struct list_head __devices;
523 struct list_head __targets;
525 struct list_head starved_list;
527 spinlock_t default_lock;
528 spinlock_t *host_lock;
530 struct mutex scan_mutex;/* serialize scanning activity */
532 struct list_head eh_cmd_q;
533 struct task_struct * ehandler; /* Error recovery thread. */
534 struct completion * eh_action; /* Wait for specific actions on the
536 wait_queue_head_t host_wait;
537 struct scsi_host_template *hostt;
538 struct scsi_transport_template *transportt;
540 /* Area to keep a shared tag map */
541 struct blk_mq_tag_set tag_set;
543 atomic_t host_busy; /* commands actually active on low-level */
544 atomic_t host_blocked;
546 unsigned int host_failed; /* commands that failed.
547 protected by host_lock */
548 unsigned int host_eh_scheduled; /* EH scheduled without command */
550 unsigned int host_no; /* Used for IOCTL_GET_IDLUN, /proc/scsi et al. */
552 /* next two fields are used to bound the time spent in error handling */
554 unsigned long last_reset;
558 * These three parameters can be used to allow for wide scsi,
559 * and for host adapters that support multiple busses
560 * The last two should be set to 1 more than the actual max id
561 * or lun (e.g. 8 for SCSI parallel systems).
563 unsigned int max_channel;
568 * This is a unique identifier that must be assigned so that we
569 * have some way of identifying each detected host adapter properly
570 * and uniquely. For hosts that do not support more than one card
571 * in the system at one time, this does not need to be set. It is
572 * initialized to 0 in scsi_register.
574 unsigned int unique_id;
577 * The maximum length of SCSI commands that this host can accept.
578 * Probably 12 for most host adapters, but could be 16 for others.
579 * or 260 if the driver supports variable length cdbs.
580 * For drivers that don't set this field, a value of 12 is
583 unsigned short max_cmd_len;
588 short unsigned int sg_tablesize;
589 short unsigned int sg_prot_tablesize;
590 unsigned int max_sectors;
591 unsigned int max_segment_size;
592 unsigned long dma_boundary;
594 * In scsi-mq mode, the number of hardware queues supported by the LLD.
596 * Note: it is assumed that each hardware queue has a queue depth of
597 * can_queue. In other words, the total queue depth per host
598 * is nr_hw_queues * can_queue.
600 unsigned nr_hw_queues;
602 * Used to assign serial numbers to the cmds.
603 * Protected by the host lock.
605 unsigned long cmd_serial_number;
607 unsigned active_mode:2;
608 unsigned unchecked_isa_dma:1;
611 * Host has requested that no further requests come through for the
614 unsigned host_self_blocked:1;
617 * Host uses correct SCSI ordering not PC ordering. The bit is
618 * set for the minority of drivers whose authors actually read
621 unsigned reverse_ordering:1;
623 /* Task mgmt function in progress */
624 unsigned tmf_in_progress:1;
626 /* Asynchronous scan in progress */
627 unsigned async_scan:1;
629 /* Don't resume host in EH */
630 unsigned eh_noresume:1;
632 /* The controller does not support WRITE SAME */
633 unsigned no_write_same:1;
635 unsigned use_cmd_list:1;
637 /* Host responded with short (<36 bytes) INQUIRY result */
638 unsigned short_inquiry:1;
641 * Optional work queue to be utilized by the transport
643 char work_q_name[20];
644 struct workqueue_struct *work_q;
647 * Task management function work queue
649 struct workqueue_struct *tmf_work_q;
651 /* The transport requires the LUN bits NOT to be stored in CDB[1] */
652 unsigned no_scsi2_lun_in_cdb:1;
655 * Value host_blocked counts down from
657 unsigned int max_host_blocked;
659 /* Protection Information */
660 unsigned int prot_capabilities;
661 unsigned char prot_guard_type;
665 unsigned long io_port;
666 unsigned char n_io_port;
667 unsigned char dma_channel;
671 enum scsi_host_state shost_state;
674 struct device shost_gendev, shost_dev;
677 * Points to the transport data (if any) which is allocated
683 * Points to the physical bus device we'd use to do DMA
684 * Needed just in case we have virtual hosts.
686 struct device *dma_dev;
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.
693 unsigned long hostdata[0] /* Used for storage of host specific stuff */
694 __attribute__ ((aligned (sizeof(unsigned long))));
697 #define class_to_shost(d) \
698 container_of(d, struct Scsi_Host, shost_dev)
700 #define shost_printk(prefix, shost, fmt, a...) \
701 dev_printk(prefix, &(shost)->shost_gendev, fmt, ##a)
703 static inline void *shost_priv(struct Scsi_Host *shost)
705 return (void *)shost->hostdata;
708 int scsi_is_host_device(const struct device *);
710 static inline struct Scsi_Host *dev_to_shost(struct device *dev)
712 while (!scsi_is_host_device(dev)) {
717 return container_of(dev, struct Scsi_Host, shost_gendev);
720 static inline int scsi_host_in_recovery(struct Scsi_Host *shost)
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;
728 extern int scsi_queue_work(struct Scsi_Host *, struct work_struct *);
729 extern void scsi_flush_work(struct Scsi_Host *);
731 extern struct Scsi_Host *scsi_host_alloc(struct scsi_host_template *, int);
732 extern int __must_check scsi_add_host_with_dma(struct Scsi_Host *,
735 extern void scsi_scan_host(struct Scsi_Host *);
736 extern void scsi_rescan_device(struct device *);
737 extern void scsi_remove_host(struct Scsi_Host *);
738 extern struct Scsi_Host *scsi_host_get(struct Scsi_Host *);
739 extern int scsi_host_busy(struct Scsi_Host *shost);
740 extern void scsi_host_put(struct Scsi_Host *t);
741 extern struct Scsi_Host *scsi_host_lookup(unsigned short);
742 extern const char *scsi_host_state_name(enum scsi_host_state);
743 extern void scsi_cmd_get_serial(struct Scsi_Host *, struct scsi_cmnd *);
745 static inline int __must_check scsi_add_host(struct Scsi_Host *host,
748 return scsi_add_host_with_dma(host, dev, dev);
751 static inline struct device *scsi_get_device(struct Scsi_Host *shost)
753 return shost->shost_gendev.parent;
757 * scsi_host_scan_allowed - Is scanning of this host allowed
758 * @shost: Pointer to Scsi_Host.
760 static inline int scsi_host_scan_allowed(struct Scsi_Host *shost)
762 return shost->shost_state == SHOST_RUNNING ||
763 shost->shost_state == SHOST_RECOVERY;
766 extern void scsi_unblock_requests(struct Scsi_Host *);
767 extern void scsi_block_requests(struct Scsi_Host *);
769 struct class_container;
772 * These two functions are used to allocate and free a pseudo device
773 * which will connect to the host adapter itself rather than any
774 * physical device. You must deallocate when you are done with the
775 * thing. This physical pseudo-device isn't real and won't be available
776 * from any high-level drivers.
778 extern void scsi_free_host_dev(struct scsi_device *);
779 extern struct scsi_device *scsi_get_host_dev(struct Scsi_Host *);
782 * DIF defines the exchange of protection information between
783 * initiator and SBC block device.
785 * DIX defines the exchange of protection information between OS and
788 enum scsi_host_prot_capabilities {
789 SHOST_DIF_TYPE1_PROTECTION = 1 << 0, /* T10 DIF Type 1 */
790 SHOST_DIF_TYPE2_PROTECTION = 1 << 1, /* T10 DIF Type 2 */
791 SHOST_DIF_TYPE3_PROTECTION = 1 << 2, /* T10 DIF Type 3 */
793 SHOST_DIX_TYPE0_PROTECTION = 1 << 3, /* DIX between OS and HBA only */
794 SHOST_DIX_TYPE1_PROTECTION = 1 << 4, /* DIX with DIF Type 1 */
795 SHOST_DIX_TYPE2_PROTECTION = 1 << 5, /* DIX with DIF Type 2 */
796 SHOST_DIX_TYPE3_PROTECTION = 1 << 6, /* DIX with DIF Type 3 */
800 * SCSI hosts which support the Data Integrity Extensions must
801 * indicate their capabilities by setting the prot_capabilities using
804 static inline void scsi_host_set_prot(struct Scsi_Host *shost, unsigned int mask)
806 shost->prot_capabilities = mask;
809 static inline unsigned int scsi_host_get_prot(struct Scsi_Host *shost)
811 return shost->prot_capabilities;
814 static inline int scsi_host_prot_dma(struct Scsi_Host *shost)
816 return shost->prot_capabilities >= SHOST_DIX_TYPE0_PROTECTION;
819 static inline unsigned int scsi_host_dif_capable(struct Scsi_Host *shost, unsigned int target_type)
821 static unsigned char cap[] = { 0,
822 SHOST_DIF_TYPE1_PROTECTION,
823 SHOST_DIF_TYPE2_PROTECTION,
824 SHOST_DIF_TYPE3_PROTECTION };
826 if (target_type >= ARRAY_SIZE(cap))
829 return shost->prot_capabilities & cap[target_type] ? target_type : 0;
832 static inline unsigned int scsi_host_dix_capable(struct Scsi_Host *shost, unsigned int target_type)
834 #if defined(CONFIG_BLK_DEV_INTEGRITY)
835 static unsigned char cap[] = { SHOST_DIX_TYPE0_PROTECTION,
836 SHOST_DIX_TYPE1_PROTECTION,
837 SHOST_DIX_TYPE2_PROTECTION,
838 SHOST_DIX_TYPE3_PROTECTION };
840 if (target_type >= ARRAY_SIZE(cap))
843 return shost->prot_capabilities & cap[target_type];
849 * All DIX-capable initiators must support the T10-mandated CRC
850 * checksum. Controllers can optionally implement the IP checksum
851 * scheme which has much lower impact on system performance. Note
852 * that the main rationale for the checksum is to match integrity
853 * metadata with data. Detecting bit errors are a job for ECC memory
857 enum scsi_host_guard_type {
858 SHOST_DIX_GUARD_CRC = 1 << 0,
859 SHOST_DIX_GUARD_IP = 1 << 1,
862 static inline void scsi_host_set_guard(struct Scsi_Host *shost, unsigned char type)
864 shost->prot_guard_type = type;
867 static inline unsigned char scsi_host_get_guard(struct Scsi_Host *shost)
869 return shost->prot_guard_type;
872 extern int scsi_host_set_state(struct Scsi_Host *, enum scsi_host_state);
874 #endif /* _SCSI_SCSI_HOST_H */