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>
21 struct scsi_transport_template;
24 #define SG_ALL SG_CHUNK_SIZE
26 #define MODE_UNKNOWN 0x00
27 #define MODE_INITIATOR 0x01
28 #define MODE_TARGET 0x02
30 struct scsi_host_template {
32 * Put fields referenced in IO submission path together in
37 * Additional per-command data allocated for the driver.
39 unsigned int cmd_size;
42 * The queuecommand function is used to queue up a scsi
43 * command block to the LLDD. When the driver finished
44 * processing the command the done callback is invoked.
46 * If queuecommand returns 0, then the driver has accepted the
47 * command. It must also push it to the HBA if the scsi_cmnd
48 * flag SCMD_LAST is set, or if the driver does not implement
49 * commit_rqs. The done() function must be called on the command
50 * when the driver has finished with it. (you may call done on the
51 * command before queuecommand returns, but in this case you
52 * *must* return 0 from queuecommand).
54 * Queuecommand may also reject the command, in which case it may
55 * not touch the command and must not call done() for it.
57 * There are two possible rejection returns:
59 * SCSI_MLQUEUE_DEVICE_BUSY: Block this device temporarily, but
60 * allow commands to other devices serviced by this host.
62 * SCSI_MLQUEUE_HOST_BUSY: Block all devices served by this
65 * For compatibility, any other non-zero return is treated the
66 * same as SCSI_MLQUEUE_HOST_BUSY.
68 * NOTE: "temporarily" means either until the next command for#
69 * this device/host completes, or a period of time determined by
70 * I/O pressure in the system if there are no other outstanding
75 int (* queuecommand)(struct Scsi_Host *, struct scsi_cmnd *);
78 * The commit_rqs function is used to trigger a hardware
79 * doorbell after some requests have been queued with
80 * queuecommand, when an error is encountered before sending
81 * the request with SCMD_LAST set.
85 void (*commit_rqs)(struct Scsi_Host *, u16);
87 struct module *module;
91 * The info function will return whatever useful information the
92 * developer sees fit. If not provided, then the name field will
97 const char *(*info)(struct Scsi_Host *);
104 int (*ioctl)(struct scsi_device *dev, unsigned int cmd,
110 * Compat handler. Handle 32bit ABI.
111 * When unknown ioctl is passed return -ENOIOCTLCMD.
115 int (*compat_ioctl)(struct scsi_device *dev, unsigned int cmd,
119 int (*init_cmd_priv)(struct Scsi_Host *shost, struct scsi_cmnd *cmd);
120 int (*exit_cmd_priv)(struct Scsi_Host *shost, struct scsi_cmnd *cmd);
123 * This is an error handling strategy routine. You don't need to
124 * define one of these if you don't want to - there is a default
125 * routine that is present that should work in most cases. For those
126 * driver authors that have the inclination and ability to write their
127 * own strategy routine, this is where it is specified. Note - the
128 * strategy routine is *ALWAYS* run in the context of the kernel eh
129 * thread. Thus you are guaranteed to *NOT* be in an interrupt
130 * handler when you execute this, and you are also guaranteed to
131 * *NOT* have any other commands being queued while you are in the
132 * strategy routine. When you return from this function, operations
135 * See scsi_error.c scsi_unjam_host for additional comments about
136 * what this function should and should not be attempting to do.
138 * Status: REQUIRED (at least one of them)
140 int (* eh_abort_handler)(struct scsi_cmnd *);
141 int (* eh_device_reset_handler)(struct scsi_cmnd *);
142 int (* eh_target_reset_handler)(struct scsi_cmnd *);
143 int (* eh_bus_reset_handler)(struct scsi_cmnd *);
144 int (* eh_host_reset_handler)(struct scsi_cmnd *);
147 * Before the mid layer attempts to scan for a new device where none
148 * currently exists, it will call this entry in your driver. Should
149 * your driver need to allocate any structs or perform any other init
150 * items in order to send commands to a currently unused target/lun
151 * combo, then this is where you can perform those allocations. This
152 * is specifically so that drivers won't have to perform any kind of
153 * "is this a new device" checks in their queuecommand routine,
154 * thereby making the hot path a bit quicker.
156 * Return values: 0 on success, non-0 on failure
158 * Deallocation: If we didn't find any devices at this ID, you will
159 * get an immediate call to slave_destroy(). If we find something
160 * here then you will get a call to slave_configure(), then the
161 * device will be used for however long it is kept around, then when
162 * the device is removed from the system (or * possibly at reboot
163 * time), you will then get a call to slave_destroy(). This is
164 * assuming you implement slave_configure and slave_destroy.
165 * However, if you allocate memory and hang it off the device struct,
166 * then you must implement the slave_destroy() routine at a minimum
167 * in order to avoid leaking memory
168 * each time a device is tore down.
172 int (* slave_alloc)(struct scsi_device *);
175 * Once the device has responded to an INQUIRY and we know the
176 * device is online, we call into the low level driver with the
177 * struct scsi_device *. If the low level device driver implements
178 * this function, it *must* perform the task of setting the queue
179 * depth on the device. All other tasks are optional and depend
180 * on what the driver supports and various implementation details.
182 * Things currently recommended to be handled at this time include:
184 * 1. Setting the device queue depth. Proper setting of this is
185 * described in the comments for scsi_change_queue_depth.
186 * 2. Determining if the device supports the various synchronous
187 * negotiation protocols. The device struct will already have
188 * responded to INQUIRY and the results of the standard items
189 * will have been shoved into the various device flag bits, eg.
190 * device->sdtr will be true if the device supports SDTR messages.
191 * 3. Allocating command structs that the device will need.
192 * 4. Setting the default timeout on this device (if needed).
193 * 5. Anything else the low level driver might want to do on a device
194 * specific setup basis...
195 * 6. Return 0 on success, non-0 on error. The device will be marked
196 * as offline on error so that no access will occur. If you return
197 * non-0, your slave_destroy routine will never get called for this
198 * device, so don't leave any loose memory hanging around, clean
199 * up after yourself before returning non-0
203 int (* slave_configure)(struct scsi_device *);
206 * Immediately prior to deallocating the device and after all activity
207 * has ceased the mid layer calls this point so that the low level
208 * driver may completely detach itself from the scsi device and vice
209 * versa. The low level driver is responsible for freeing any memory
210 * it allocated in the slave_alloc or slave_configure calls.
214 void (* slave_destroy)(struct scsi_device *);
217 * Before the mid layer attempts to scan for a new device attached
218 * to a target where no target currently exists, it will call this
219 * entry in your driver. Should your driver need to allocate any
220 * structs or perform any other init items in order to send commands
221 * to a currently unused target, then this is where you can perform
224 * Return values: 0 on success, non-0 on failure
228 int (* target_alloc)(struct scsi_target *);
231 * Immediately prior to deallocating the target structure, and
232 * after all activity to attached scsi devices has ceased, the
233 * midlayer calls this point so that the driver may deallocate
234 * and terminate any references to the target.
238 void (* target_destroy)(struct scsi_target *);
241 * If a host has the ability to discover targets on its own instead
242 * of scanning the entire bus, it can fill in this function and
243 * call scsi_scan_host(). This function will be called periodically
244 * until it returns 1 with the scsi_host and the elapsed time of
245 * the scan in jiffies.
249 int (* scan_finished)(struct Scsi_Host *, unsigned long);
252 * If the host wants to be called before the scan starts, but
253 * after the midlayer has set up ready for the scan, it can fill
258 void (* scan_start)(struct Scsi_Host *);
261 * Fill in this function to allow the queue depth of this host
262 * to be changeable (on a per device basis). Returns either
263 * the current queue depth setting (may be different from what
264 * was passed in) or an error. An error should only be
265 * returned if the requested depth is legal but the driver was
266 * unable to set it. If the requested depth is illegal, the
267 * driver should set and return the closest legal queue depth.
271 int (* change_queue_depth)(struct scsi_device *, int);
274 * This functions lets the driver expose the queue mapping
275 * to the block layer.
279 int (* map_queues)(struct Scsi_Host *shost);
282 * SCSI interface of blk_poll - poll for IO completions.
283 * Only applicable if SCSI LLD exposes multiple h/w queues.
285 * Return value: Number of completed entries found.
289 int (* mq_poll)(struct Scsi_Host *shost, unsigned int queue_num);
292 * Check if scatterlists need to be padded for DMA draining.
296 bool (* dma_need_drain)(struct request *rq);
299 * This function determines the BIOS parameters for a given
300 * harddisk. These tend to be numbers that are made up by
301 * the host adapter. Parameters:
302 * size, device, list (heads, sectors, cylinders)
306 int (* bios_param)(struct scsi_device *, struct block_device *,
310 * This function is called when one or more partitions on the
311 * device reach beyond the end of the device.
315 void (*unlock_native_capacity)(struct scsi_device *);
318 * Can be used to export driver statistics and other infos to the
319 * world outside the kernel ie. userspace and it also provides an
320 * interface to feed the driver with information.
324 int (*show_info)(struct seq_file *, struct Scsi_Host *);
325 int (*write_info)(struct Scsi_Host *, char *, int);
328 * This is an optional routine that allows the transport to become
329 * involved when a scsi io timer fires. The return value tells the
330 * timer routine how to finish the io timeout handling.
334 enum blk_eh_timer_return (*eh_timed_out)(struct scsi_cmnd *);
336 * Optional routine that allows the transport to decide if a cmd
337 * is retryable. Return true if the transport is in a state the
338 * cmd should be retried on.
340 bool (*eh_should_retry_cmd)(struct scsi_cmnd *scmd);
342 /* This is an optional routine that allows transport to initiate
343 * LLD adapter or firmware reset using sysfs attribute.
345 * Return values: 0 on success, -ve value on failure.
350 int (*host_reset)(struct Scsi_Host *shost, int reset_type);
351 #define SCSI_ADAPTER_RESET 1
352 #define SCSI_FIRMWARE_RESET 2
356 * Name of proc directory
358 const char *proc_name;
361 * Used to store the procfs directory if a driver implements the
364 struct proc_dir_entry *proc_dir;
367 * This determines if we will use a non-interrupt driven
368 * or an interrupt driven scheme. It is set to the maximum number
369 * of simultaneous commands a single hw queue in HBA will accept.
374 * In many instances, especially where disconnect / reconnect are
375 * supported, our host also has an ID on the SCSI bus. If this is
376 * the case, then it must be reserved. Please set this_id to -1 if
377 * your setup is in single initiator mode, and the host lacks an
383 * This determines the degree to which the host adapter is capable
386 unsigned short sg_tablesize;
387 unsigned short sg_prot_tablesize;
390 * Set this if the host adapter has limitations beside segment count.
392 unsigned int max_sectors;
395 * Maximum size in bytes of a single segment.
397 unsigned int max_segment_size;
400 * DMA scatter gather segment boundary limit. A segment crossing this
401 * boundary will be split in two.
403 unsigned long dma_boundary;
405 unsigned long virt_boundary_mask;
408 * This specifies "machine infinity" for host templates which don't
409 * limit the transfer size. Note this limit represents an absolute
410 * maximum, and may be over the transfer limits allowed for
411 * individual devices (e.g. 256 for SCSI-1).
413 #define SCSI_DEFAULT_MAX_SECTORS 1024
416 * True if this host adapter can make good use of linked commands.
417 * This will allow more than one command to be queued to a given
418 * unit on a given host. Set this to the maximum number of command
419 * blocks to be provided for each device. Set this to 1 for one
420 * command block per lun, 2 for two, etc. Do not set this to 0.
421 * You should make sure that the host adapter will do the right thing
422 * before you try setting this above 1.
427 * present contains counter indicating how many boards of this
428 * type were found when we did the scan.
430 unsigned char present;
432 /* If use block layer to manage tags, this is tag allocation policy */
433 int tag_alloc_policy;
436 * Track QUEUE_FULL events and reduce queue depth on demand.
438 unsigned track_queue_depth:1;
441 * This specifies the mode that a LLD supports.
443 unsigned supported_mode:2;
446 * True for emulated SCSI host adapters (e.g. ATAPI).
451 * True if the low-level driver performs its own reset-settle delays.
453 unsigned skip_settle_delay:1;
455 /* True if the controller does not support WRITE SAME */
456 unsigned no_write_same:1;
458 /* True if the host uses host-wide tagspace */
459 unsigned host_tagset:1;
462 * Countdown for host blocking with no commands outstanding.
464 unsigned int max_host_blocked;
467 * Default value for the blocking. If the queue is empty,
468 * host_blocked counts down in the request_fn until it restarts
469 * host operations as zero is reached.
471 * FIXME: This should probably be a value in the template
473 #define SCSI_DEFAULT_HOST_BLOCKED 7
476 * Pointer to the SCSI host sysfs attribute groups, NULL terminated.
478 const struct attribute_group **shost_groups;
481 * Pointer to the SCSI device attribute groups for this host,
484 const struct attribute_group **sdev_groups;
487 * Vendor Identifier associated with the host
489 * Note: When specifying vendor_id, be sure to read the
490 * Vendor Type and ID formatting requirements specified in
495 /* Delay for runtime autosuspend */
496 int rpm_autosuspend_delay;
500 * Temporary #define for host lock push down. Can be removed when all
501 * drivers have been updated to take advantage of unlocked
505 #define DEF_SCSI_QCMD(func_name) \
506 int func_name(struct Scsi_Host *shost, struct scsi_cmnd *cmd) \
508 unsigned long irq_flags; \
510 spin_lock_irqsave(shost->host_lock, irq_flags); \
511 rc = func_name##_lck(cmd); \
512 spin_unlock_irqrestore(shost->host_lock, irq_flags); \
518 * shost state: If you alter this, you also need to alter scsi_sysfs.c
519 * (for the ascii descriptions) and the state model enforcer:
520 * scsi_host_set_state()
522 enum scsi_host_state {
528 SHOST_CANCEL_RECOVERY,
534 * __devices is protected by the host_lock, but you should
535 * usually use scsi_device_lookup / shost_for_each_device
536 * to access it and don't care about locking yourself.
537 * In the rare case of being in irq context you can use
538 * their __ prefixed variants with the lock held. NEVER
539 * access this list directly from a driver.
541 struct list_head __devices;
542 struct list_head __targets;
544 struct list_head starved_list;
546 spinlock_t default_lock;
547 spinlock_t *host_lock;
549 struct mutex scan_mutex;/* serialize scanning activity */
551 struct list_head eh_abort_list;
552 struct list_head eh_cmd_q;
553 struct task_struct * ehandler; /* Error recovery thread. */
554 struct completion * eh_action; /* Wait for specific actions on the
556 wait_queue_head_t host_wait;
557 struct scsi_host_template *hostt;
558 struct scsi_transport_template *transportt;
560 /* Area to keep a shared tag map */
561 struct blk_mq_tag_set tag_set;
563 atomic_t host_blocked;
565 unsigned int host_failed; /* commands that failed.
566 protected by host_lock */
567 unsigned int host_eh_scheduled; /* EH scheduled without command */
569 unsigned int host_no; /* Used for IOCTL_GET_IDLUN, /proc/scsi et al. */
571 /* next two fields are used to bound the time spent in error handling */
573 unsigned long last_reset;
577 * These three parameters can be used to allow for wide scsi,
578 * and for host adapters that support multiple busses
579 * The last two should be set to 1 more than the actual max id
580 * or lun (e.g. 8 for SCSI parallel systems).
582 unsigned int max_channel;
587 * This is a unique identifier that must be assigned so that we
588 * have some way of identifying each detected host adapter properly
589 * and uniquely. For hosts that do not support more than one card
590 * in the system at one time, this does not need to be set. It is
591 * initialized to 0 in scsi_register.
593 unsigned int unique_id;
596 * The maximum length of SCSI commands that this host can accept.
597 * Probably 12 for most host adapters, but could be 16 for others.
598 * or 260 if the driver supports variable length cdbs.
599 * For drivers that don't set this field, a value of 12 is
602 unsigned short max_cmd_len;
607 short unsigned int sg_tablesize;
608 short unsigned int sg_prot_tablesize;
609 unsigned int max_sectors;
610 unsigned int max_segment_size;
611 unsigned long dma_boundary;
612 unsigned long virt_boundary_mask;
614 * In scsi-mq mode, the number of hardware queues supported by the LLD.
616 * Note: it is assumed that each hardware queue has a queue depth of
617 * can_queue. In other words, the total queue depth per host
618 * is nr_hw_queues * can_queue. However, for when host_tagset is set,
619 * the total queue depth is can_queue.
621 unsigned nr_hw_queues;
623 unsigned active_mode:2;
626 * Host has requested that no further requests come through for the
629 unsigned host_self_blocked:1;
632 * Host uses correct SCSI ordering not PC ordering. The bit is
633 * set for the minority of drivers whose authors actually read
636 unsigned reverse_ordering:1;
638 /* Task mgmt function in progress */
639 unsigned tmf_in_progress:1;
641 /* Asynchronous scan in progress */
642 unsigned async_scan:1;
644 /* Don't resume host in EH */
645 unsigned eh_noresume:1;
647 /* The controller does not support WRITE SAME */
648 unsigned no_write_same:1;
650 /* True if the host uses host-wide tagspace */
651 unsigned host_tagset:1;
653 /* Host responded with short (<36 bytes) INQUIRY result */
654 unsigned short_inquiry:1;
656 /* The transport requires the LUN bits NOT to be stored in CDB[1] */
657 unsigned no_scsi2_lun_in_cdb:1;
660 * Optional work queue to be utilized by the transport
662 char work_q_name[20];
663 struct workqueue_struct *work_q;
666 * Task management function work queue
668 struct workqueue_struct *tmf_work_q;
671 * Value host_blocked counts down from
673 unsigned int max_host_blocked;
675 /* Protection Information */
676 unsigned int prot_capabilities;
677 unsigned char prot_guard_type;
681 unsigned long io_port;
682 unsigned char n_io_port;
683 unsigned char dma_channel;
687 enum scsi_host_state shost_state;
690 struct device shost_gendev, shost_dev;
692 atomic_t target_count;
693 wait_queue_head_t targets_wq;
696 * Points to the transport data (if any) which is allocated
702 * Points to the physical bus device we'd use to do DMA
703 * Needed just in case we have virtual hosts.
705 struct device *dma_dev;
708 * We should ensure that this is aligned, both for better performance
709 * and also because some compilers (m68k) don't automatically force
710 * alignment to a long boundary.
712 unsigned long hostdata[] /* Used for storage of host specific stuff */
713 __attribute__ ((aligned (sizeof(unsigned long))));
716 #define class_to_shost(d) \
717 container_of(d, struct Scsi_Host, shost_dev)
719 #define shost_printk(prefix, shost, fmt, a...) \
720 dev_printk(prefix, &(shost)->shost_gendev, fmt, ##a)
722 static inline void *shost_priv(struct Scsi_Host *shost)
724 return (void *)shost->hostdata;
727 int scsi_is_host_device(const struct device *);
729 static inline struct Scsi_Host *dev_to_shost(struct device *dev)
731 while (!scsi_is_host_device(dev)) {
736 return container_of(dev, struct Scsi_Host, shost_gendev);
739 static inline int scsi_host_in_recovery(struct Scsi_Host *shost)
741 return shost->shost_state == SHOST_RECOVERY ||
742 shost->shost_state == SHOST_CANCEL_RECOVERY ||
743 shost->shost_state == SHOST_DEL_RECOVERY ||
744 shost->tmf_in_progress;
747 extern int scsi_queue_work(struct Scsi_Host *, struct work_struct *);
748 extern void scsi_flush_work(struct Scsi_Host *);
750 extern struct Scsi_Host *scsi_host_alloc(struct scsi_host_template *, int);
751 extern int __must_check scsi_add_host_with_dma(struct Scsi_Host *,
754 extern void scsi_scan_host(struct Scsi_Host *);
755 extern void scsi_rescan_device(struct device *);
756 extern void scsi_remove_host(struct Scsi_Host *);
757 extern struct Scsi_Host *scsi_host_get(struct Scsi_Host *);
758 extern int scsi_host_busy(struct Scsi_Host *shost);
759 extern void scsi_host_put(struct Scsi_Host *t);
760 extern struct Scsi_Host *scsi_host_lookup(unsigned short);
761 extern const char *scsi_host_state_name(enum scsi_host_state);
762 extern void scsi_host_complete_all_commands(struct Scsi_Host *shost,
763 enum scsi_host_status status);
765 static inline int __must_check scsi_add_host(struct Scsi_Host *host,
768 return scsi_add_host_with_dma(host, dev, dev);
771 static inline struct device *scsi_get_device(struct Scsi_Host *shost)
773 return shost->shost_gendev.parent;
777 * scsi_host_scan_allowed - Is scanning of this host allowed
778 * @shost: Pointer to Scsi_Host.
780 static inline int scsi_host_scan_allowed(struct Scsi_Host *shost)
782 return shost->shost_state == SHOST_RUNNING ||
783 shost->shost_state == SHOST_RECOVERY;
786 extern void scsi_unblock_requests(struct Scsi_Host *);
787 extern void scsi_block_requests(struct Scsi_Host *);
788 extern int scsi_host_block(struct Scsi_Host *shost);
789 extern int scsi_host_unblock(struct Scsi_Host *shost, int new_state);
791 void scsi_host_busy_iter(struct Scsi_Host *,
792 bool (*fn)(struct scsi_cmnd *, void *, bool), void *priv);
794 struct class_container;
797 * DIF defines the exchange of protection information between
798 * initiator and SBC block device.
800 * DIX defines the exchange of protection information between OS and
803 enum scsi_host_prot_capabilities {
804 SHOST_DIF_TYPE1_PROTECTION = 1 << 0, /* T10 DIF Type 1 */
805 SHOST_DIF_TYPE2_PROTECTION = 1 << 1, /* T10 DIF Type 2 */
806 SHOST_DIF_TYPE3_PROTECTION = 1 << 2, /* T10 DIF Type 3 */
808 SHOST_DIX_TYPE0_PROTECTION = 1 << 3, /* DIX between OS and HBA only */
809 SHOST_DIX_TYPE1_PROTECTION = 1 << 4, /* DIX with DIF Type 1 */
810 SHOST_DIX_TYPE2_PROTECTION = 1 << 5, /* DIX with DIF Type 2 */
811 SHOST_DIX_TYPE3_PROTECTION = 1 << 6, /* DIX with DIF Type 3 */
815 * SCSI hosts which support the Data Integrity Extensions must
816 * indicate their capabilities by setting the prot_capabilities using
819 static inline void scsi_host_set_prot(struct Scsi_Host *shost, unsigned int mask)
821 shost->prot_capabilities = mask;
824 static inline unsigned int scsi_host_get_prot(struct Scsi_Host *shost)
826 return shost->prot_capabilities;
829 static inline int scsi_host_prot_dma(struct Scsi_Host *shost)
831 return shost->prot_capabilities >= SHOST_DIX_TYPE0_PROTECTION;
834 static inline unsigned int scsi_host_dif_capable(struct Scsi_Host *shost, unsigned int target_type)
836 static unsigned char cap[] = { 0,
837 SHOST_DIF_TYPE1_PROTECTION,
838 SHOST_DIF_TYPE2_PROTECTION,
839 SHOST_DIF_TYPE3_PROTECTION };
841 if (target_type >= ARRAY_SIZE(cap))
844 return shost->prot_capabilities & cap[target_type] ? target_type : 0;
847 static inline unsigned int scsi_host_dix_capable(struct Scsi_Host *shost, unsigned int target_type)
849 #if defined(CONFIG_BLK_DEV_INTEGRITY)
850 static unsigned char cap[] = { SHOST_DIX_TYPE0_PROTECTION,
851 SHOST_DIX_TYPE1_PROTECTION,
852 SHOST_DIX_TYPE2_PROTECTION,
853 SHOST_DIX_TYPE3_PROTECTION };
855 if (target_type >= ARRAY_SIZE(cap))
858 return shost->prot_capabilities & cap[target_type];
864 * All DIX-capable initiators must support the T10-mandated CRC
865 * checksum. Controllers can optionally implement the IP checksum
866 * scheme which has much lower impact on system performance. Note
867 * that the main rationale for the checksum is to match integrity
868 * metadata with data. Detecting bit errors are a job for ECC memory
872 enum scsi_host_guard_type {
873 SHOST_DIX_GUARD_CRC = 1 << 0,
874 SHOST_DIX_GUARD_IP = 1 << 1,
877 static inline void scsi_host_set_guard(struct Scsi_Host *shost, unsigned char type)
879 shost->prot_guard_type = type;
882 static inline unsigned char scsi_host_get_guard(struct Scsi_Host *shost)
884 return shost->prot_guard_type;
887 extern int scsi_host_set_state(struct Scsi_Host *, enum scsi_host_state);
889 #endif /* _SCSI_SCSI_HOST_H */