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_transport_template
;
25 #define SG_ALL SG_CHUNK_SIZE
27 #define MODE_UNKNOWN 0x00
28 #define MODE_INITIATOR 0x01
29 #define MODE_TARGET 0x02
31 struct scsi_host_template
{
33 * Put fields referenced in IO submission path together in
38 * Additional per-command data allocated for the driver.
40 unsigned int cmd_size
;
43 * The queuecommand function is used to queue up a scsi
44 * command block to the LLDD. When the driver finished
45 * processing the command the done callback is invoked.
47 * If queuecommand returns 0, then the driver has accepted the
48 * command. It must also push it to the HBA if the scsi_cmnd
49 * flag SCMD_LAST is set, or if the driver does not implement
50 * commit_rqs. The done() function must be called on the command
51 * when the driver has finished with it. (you may call done on the
52 * command before queuecommand returns, but in this case you
53 * *must* return 0 from queuecommand).
55 * Queuecommand may also reject the command, in which case it may
56 * not touch the command and must not call done() for it.
58 * There are two possible rejection returns:
60 * SCSI_MLQUEUE_DEVICE_BUSY: Block this device temporarily, but
61 * allow commands to other devices serviced by this host.
63 * SCSI_MLQUEUE_HOST_BUSY: Block all devices served by this
66 * For compatibility, any other non-zero return is treated the
67 * same as SCSI_MLQUEUE_HOST_BUSY.
69 * NOTE: "temporarily" means either until the next command for#
70 * this device/host completes, or a period of time determined by
71 * I/O pressure in the system if there are no other outstanding
76 int (* queuecommand
)(struct Scsi_Host
*, struct scsi_cmnd
*);
79 * The commit_rqs function is used to trigger a hardware
80 * doorbell after some requests have been queued with
81 * queuecommand, when an error is encountered before sending
82 * the request with SCMD_LAST set.
86 void (*commit_rqs
)(struct Scsi_Host
*, u16
);
88 struct module
*module
;
92 * The info function will return whatever useful information the
93 * developer sees fit. If not provided, then the name field will
98 const char *(*info
)(struct Scsi_Host
*);
105 int (*ioctl
)(struct scsi_device
*dev
, unsigned int cmd
,
111 * Compat handler. Handle 32bit ABI.
112 * When unknown ioctl is passed return -ENOIOCTLCMD.
116 int (*compat_ioctl
)(struct scsi_device
*dev
, unsigned int cmd
,
120 int (*init_cmd_priv
)(struct Scsi_Host
*shost
, struct scsi_cmnd
*cmd
);
121 int (*exit_cmd_priv
)(struct Scsi_Host
*shost
, struct scsi_cmnd
*cmd
);
124 * This is an error handling strategy routine. You don't need to
125 * define one of these if you don't want to - there is a default
126 * routine that is present that should work in most cases. For those
127 * driver authors that have the inclination and ability to write their
128 * own strategy routine, this is where it is specified. Note - the
129 * strategy routine is *ALWAYS* run in the context of the kernel eh
130 * thread. Thus you are guaranteed to *NOT* be in an interrupt
131 * handler when you execute this, and you are also guaranteed to
132 * *NOT* have any other commands being queued while you are in the
133 * strategy routine. When you return from this function, operations
136 * See scsi_error.c scsi_unjam_host for additional comments about
137 * what this function should and should not be attempting to do.
139 * Status: REQUIRED (at least one of them)
141 int (* eh_abort_handler
)(struct scsi_cmnd
*);
142 int (* eh_device_reset_handler
)(struct scsi_cmnd
*);
143 int (* eh_target_reset_handler
)(struct scsi_cmnd
*);
144 int (* eh_bus_reset_handler
)(struct scsi_cmnd
*);
145 int (* eh_host_reset_handler
)(struct scsi_cmnd
*);
148 * Before the mid layer attempts to scan for a new device where none
149 * currently exists, it will call this entry in your driver. Should
150 * your driver need to allocate any structs or perform any other init
151 * items in order to send commands to a currently unused target/lun
152 * combo, then this is where you can perform those allocations. This
153 * is specifically so that drivers won't have to perform any kind of
154 * "is this a new device" checks in their queuecommand routine,
155 * thereby making the hot path a bit quicker.
157 * Return values: 0 on success, non-0 on failure
159 * Deallocation: If we didn't find any devices at this ID, you will
160 * get an immediate call to slave_destroy(). If we find something
161 * here then you will get a call to slave_configure(), then the
162 * device will be used for however long it is kept around, then when
163 * the device is removed from the system (or * possibly at reboot
164 * time), you will then get a call to slave_destroy(). This is
165 * assuming you implement slave_configure and slave_destroy.
166 * However, if you allocate memory and hang it off the device struct,
167 * then you must implement the slave_destroy() routine at a minimum
168 * in order to avoid leaking memory
169 * each time a device is tore down.
173 int (* slave_alloc
)(struct scsi_device
*);
176 * Once the device has responded to an INQUIRY and we know the
177 * device is online, we call into the low level driver with the
178 * struct scsi_device *. If the low level device driver implements
179 * this function, it *must* perform the task of setting the queue
180 * depth on the device. All other tasks are optional and depend
181 * on what the driver supports and various implementation details.
183 * Things currently recommended to be handled at this time include:
185 * 1. Setting the device queue depth. Proper setting of this is
186 * described in the comments for scsi_change_queue_depth.
187 * 2. Determining if the device supports the various synchronous
188 * negotiation protocols. The device struct will already have
189 * responded to INQUIRY and the results of the standard items
190 * will have been shoved into the various device flag bits, eg.
191 * device->sdtr will be true if the device supports SDTR messages.
192 * 3. Allocating command structs that the device will need.
193 * 4. Setting the default timeout on this device (if needed).
194 * 5. Anything else the low level driver might want to do on a device
195 * specific setup basis...
196 * 6. Return 0 on success, non-0 on error. The device will be marked
197 * as offline on error so that no access will occur. If you return
198 * non-0, your slave_destroy routine will never get called for this
199 * device, so don't leave any loose memory hanging around, clean
200 * up after yourself before returning non-0
204 int (* slave_configure
)(struct scsi_device
*);
207 * Immediately prior to deallocating the device and after all activity
208 * has ceased the mid layer calls this point so that the low level
209 * driver may completely detach itself from the scsi device and vice
210 * versa. The low level driver is responsible for freeing any memory
211 * it allocated in the slave_alloc or slave_configure calls.
215 void (* slave_destroy
)(struct scsi_device
*);
218 * Before the mid layer attempts to scan for a new device attached
219 * to a target where no target currently exists, it will call this
220 * entry in your driver. Should your driver need to allocate any
221 * structs or perform any other init items in order to send commands
222 * to a currently unused target, then this is where you can perform
225 * Return values: 0 on success, non-0 on failure
229 int (* target_alloc
)(struct scsi_target
*);
232 * Immediately prior to deallocating the target structure, and
233 * after all activity to attached scsi devices has ceased, the
234 * midlayer calls this point so that the driver may deallocate
235 * and terminate any references to the target.
239 void (* target_destroy
)(struct scsi_target
*);
242 * If a host has the ability to discover targets on its own instead
243 * of scanning the entire bus, it can fill in this function and
244 * call scsi_scan_host(). This function will be called periodically
245 * until it returns 1 with the scsi_host and the elapsed time of
246 * the scan in jiffies.
250 int (* scan_finished
)(struct Scsi_Host
*, unsigned long);
253 * If the host wants to be called before the scan starts, but
254 * after the midlayer has set up ready for the scan, it can fill
259 void (* scan_start
)(struct Scsi_Host
*);
262 * Fill in this function to allow the queue depth of this host
263 * to be changeable (on a per device basis). Returns either
264 * the current queue depth setting (may be different from what
265 * was passed in) or an error. An error should only be
266 * returned if the requested depth is legal but the driver was
267 * unable to set it. If the requested depth is illegal, the
268 * driver should set and return the closest legal queue depth.
272 int (* change_queue_depth
)(struct scsi_device
*, int);
275 * This functions lets the driver expose the queue mapping
276 * to the block layer.
280 int (* map_queues
)(struct Scsi_Host
*shost
);
283 * SCSI interface of blk_poll - poll for IO completions.
284 * Only applicable if SCSI LLD exposes multiple h/w queues.
286 * Return value: Number of completed entries found.
290 int (* mq_poll
)(struct Scsi_Host
*shost
, unsigned int queue_num
);
293 * Check if scatterlists need to be padded for DMA draining.
297 bool (* dma_need_drain
)(struct request
*rq
);
300 * This function determines the BIOS parameters for a given
301 * harddisk. These tend to be numbers that are made up by
302 * the host adapter. Parameters:
303 * size, device, list (heads, sectors, cylinders)
307 int (* bios_param
)(struct scsi_device
*, struct block_device
*,
311 * This function is called when one or more partitions on the
312 * device reach beyond the end of the device.
316 void (*unlock_native_capacity
)(struct scsi_device
*);
319 * Can be used to export driver statistics and other infos to the
320 * world outside the kernel ie. userspace and it also provides an
321 * interface to feed the driver with information.
325 int (*show_info
)(struct seq_file
*, struct Scsi_Host
*);
326 int (*write_info
)(struct Scsi_Host
*, char *, int);
329 * This is an optional routine that allows the transport to become
330 * involved when a scsi io timer fires. The return value tells the
331 * timer routine how to finish the io timeout handling.
335 enum blk_eh_timer_return (*eh_timed_out
)(struct scsi_cmnd
*);
337 * Optional routine that allows the transport to decide if a cmd
338 * is retryable. Return true if the transport is in a state the
339 * cmd should be retried on.
341 bool (*eh_should_retry_cmd
)(struct scsi_cmnd
*scmd
);
343 /* This is an optional routine that allows transport to initiate
344 * LLD adapter or firmware reset using sysfs attribute.
346 * Return values: 0 on success, -ve value on failure.
351 int (*host_reset
)(struct Scsi_Host
*shost
, int reset_type
);
352 #define SCSI_ADAPTER_RESET 1
353 #define SCSI_FIRMWARE_RESET 2
357 * Name of proc directory
359 const char *proc_name
;
362 * Used to store the procfs directory if a driver implements the
365 struct proc_dir_entry
*proc_dir
;
368 * This determines if we will use a non-interrupt driven
369 * or an interrupt driven scheme. It is set to the maximum number
370 * of simultaneous commands a single hw queue in HBA will accept.
375 * In many instances, especially where disconnect / reconnect are
376 * supported, our host also has an ID on the SCSI bus. If this is
377 * the case, then it must be reserved. Please set this_id to -1 if
378 * your setup is in single initiator mode, and the host lacks an
384 * This determines the degree to which the host adapter is capable
387 unsigned short sg_tablesize
;
388 unsigned short sg_prot_tablesize
;
391 * Set this if the host adapter has limitations beside segment count.
393 unsigned int max_sectors
;
396 * Maximum size in bytes of a single segment.
398 unsigned int max_segment_size
;
401 * DMA scatter gather segment boundary limit. A segment crossing this
402 * boundary will be split in two.
404 unsigned long dma_boundary
;
406 unsigned long virt_boundary_mask
;
409 * This specifies "machine infinity" for host templates which don't
410 * limit the transfer size. Note this limit represents an absolute
411 * maximum, and may be over the transfer limits allowed for
412 * individual devices (e.g. 256 for SCSI-1).
414 #define SCSI_DEFAULT_MAX_SECTORS 1024
417 * True if this host adapter can make good use of linked commands.
418 * This will allow more than one command to be queued to a given
419 * unit on a given host. Set this to the maximum number of command
420 * blocks to be provided for each device. Set this to 1 for one
421 * command block per lun, 2 for two, etc. Do not set this to 0.
422 * You should make sure that the host adapter will do the right thing
423 * before you try setting this above 1.
428 * present contains counter indicating how many boards of this
429 * type were found when we did the scan.
431 unsigned char present
;
433 /* If use block layer to manage tags, this is tag allocation policy */
434 int tag_alloc_policy
;
437 * Track QUEUE_FULL events and reduce queue depth on demand.
439 unsigned track_queue_depth
:1;
442 * This specifies the mode that a LLD supports.
444 unsigned supported_mode
:2;
447 * True for emulated SCSI host adapters (e.g. ATAPI).
452 * True if the low-level driver performs its own reset-settle delays.
454 unsigned skip_settle_delay
:1;
456 /* True if the controller does not support WRITE SAME */
457 unsigned no_write_same
:1;
459 /* True if the host uses host-wide tagspace */
460 unsigned host_tagset
:1;
463 * Countdown for host blocking with no commands outstanding.
465 unsigned int max_host_blocked
;
468 * Default value for the blocking. If the queue is empty,
469 * host_blocked counts down in the request_fn until it restarts
470 * host operations as zero is reached.
472 * FIXME: This should probably be a value in the template
474 #define SCSI_DEFAULT_HOST_BLOCKED 7
477 * Pointer to the sysfs class properties for this host, NULL terminated.
479 struct device_attribute
**shost_attrs
;
482 * Pointer to the SCSI device properties for this host, NULL terminated.
484 struct device_attribute
**sdev_attrs
;
487 * Pointer to the SCSI device attribute groups for this host,
490 const struct attribute_group
**sdev_groups
;
493 * Vendor Identifier associated with the host
495 * Note: When specifying vendor_id, be sure to read the
496 * Vendor Type and ID formatting requirements specified in
501 struct scsi_host_cmd_pool
*cmd_pool
;
503 /* Delay for runtime autosuspend */
504 int rpm_autosuspend_delay
;
508 * Temporary #define for host lock push down. Can be removed when all
509 * drivers have been updated to take advantage of unlocked
513 #define DEF_SCSI_QCMD(func_name) \
514 int func_name(struct Scsi_Host *shost, struct scsi_cmnd *cmd) \
516 unsigned long irq_flags; \
518 spin_lock_irqsave(shost->host_lock, irq_flags); \
519 rc = func_name##_lck (cmd, cmd->scsi_done); \
520 spin_unlock_irqrestore(shost->host_lock, irq_flags); \
526 * shost state: If you alter this, you also need to alter scsi_sysfs.c
527 * (for the ascii descriptions) and the state model enforcer:
528 * scsi_host_set_state()
530 enum scsi_host_state
{
536 SHOST_CANCEL_RECOVERY
,
542 * __devices is protected by the host_lock, but you should
543 * usually use scsi_device_lookup / shost_for_each_device
544 * to access it and don't care about locking yourself.
545 * In the rare case of being in irq context you can use
546 * their __ prefixed variants with the lock held. NEVER
547 * access this list directly from a driver.
549 struct list_head __devices
;
550 struct list_head __targets
;
552 struct list_head starved_list
;
554 spinlock_t default_lock
;
555 spinlock_t
*host_lock
;
557 struct mutex scan_mutex
;/* serialize scanning activity */
559 struct list_head eh_cmd_q
;
560 struct task_struct
* ehandler
; /* Error recovery thread. */
561 struct completion
* eh_action
; /* Wait for specific actions on the
563 wait_queue_head_t host_wait
;
564 struct scsi_host_template
*hostt
;
565 struct scsi_transport_template
*transportt
;
567 /* Area to keep a shared tag map */
568 struct blk_mq_tag_set tag_set
;
570 atomic_t host_blocked
;
572 unsigned int host_failed
; /* commands that failed.
573 protected by host_lock */
574 unsigned int host_eh_scheduled
; /* EH scheduled without command */
576 unsigned int host_no
; /* Used for IOCTL_GET_IDLUN, /proc/scsi et al. */
578 /* next two fields are used to bound the time spent in error handling */
580 unsigned long last_reset
;
584 * These three parameters can be used to allow for wide scsi,
585 * and for host adapters that support multiple busses
586 * The last two should be set to 1 more than the actual max id
587 * or lun (e.g. 8 for SCSI parallel systems).
589 unsigned int max_channel
;
594 * This is a unique identifier that must be assigned so that we
595 * have some way of identifying each detected host adapter properly
596 * and uniquely. For hosts that do not support more than one card
597 * in the system at one time, this does not need to be set. It is
598 * initialized to 0 in scsi_register.
600 unsigned int unique_id
;
603 * The maximum length of SCSI commands that this host can accept.
604 * Probably 12 for most host adapters, but could be 16 for others.
605 * or 260 if the driver supports variable length cdbs.
606 * For drivers that don't set this field, a value of 12 is
609 unsigned short max_cmd_len
;
614 short unsigned int sg_tablesize
;
615 short unsigned int sg_prot_tablesize
;
616 unsigned int max_sectors
;
617 unsigned int max_segment_size
;
618 unsigned long dma_boundary
;
619 unsigned long virt_boundary_mask
;
621 * In scsi-mq mode, the number of hardware queues supported by the LLD.
623 * Note: it is assumed that each hardware queue has a queue depth of
624 * can_queue. In other words, the total queue depth per host
625 * is nr_hw_queues * can_queue. However, for when host_tagset is set,
626 * the total queue depth is can_queue.
628 unsigned nr_hw_queues
;
630 unsigned active_mode
:2;
633 * Host has requested that no further requests come through for the
636 unsigned host_self_blocked
:1;
639 * Host uses correct SCSI ordering not PC ordering. The bit is
640 * set for the minority of drivers whose authors actually read
643 unsigned reverse_ordering
:1;
645 /* Task mgmt function in progress */
646 unsigned tmf_in_progress
:1;
648 /* Asynchronous scan in progress */
649 unsigned async_scan
:1;
651 /* Don't resume host in EH */
652 unsigned eh_noresume
:1;
654 /* The controller does not support WRITE SAME */
655 unsigned no_write_same
:1;
657 /* True if the host uses host-wide tagspace */
658 unsigned host_tagset
:1;
660 /* Host responded with short (<36 bytes) INQUIRY result */
661 unsigned short_inquiry
:1;
663 /* The transport requires the LUN bits NOT to be stored in CDB[1] */
664 unsigned no_scsi2_lun_in_cdb
:1;
667 * Optional work queue to be utilized by the transport
669 char work_q_name
[20];
670 struct workqueue_struct
*work_q
;
673 * Task management function work queue
675 struct workqueue_struct
*tmf_work_q
;
678 * Value host_blocked counts down from
680 unsigned int max_host_blocked
;
682 /* Protection Information */
683 unsigned int prot_capabilities
;
684 unsigned char prot_guard_type
;
688 unsigned long io_port
;
689 unsigned char n_io_port
;
690 unsigned char dma_channel
;
694 enum scsi_host_state shost_state
;
697 struct device shost_gendev
, shost_dev
;
700 * Points to the transport data (if any) which is allocated
706 * Points to the physical bus device we'd use to do DMA
707 * Needed just in case we have virtual hosts.
709 struct device
*dma_dev
;
712 * We should ensure that this is aligned, both for better performance
713 * and also because some compilers (m68k) don't automatically force
714 * alignment to a long boundary.
716 unsigned long hostdata
[] /* Used for storage of host specific stuff */
717 __attribute__ ((aligned (sizeof(unsigned long))));
720 #define class_to_shost(d) \
721 container_of(d, struct Scsi_Host, shost_dev)
723 #define shost_printk(prefix, shost, fmt, a...) \
724 dev_printk(prefix, &(shost)->shost_gendev, fmt, ##a)
726 static inline void *shost_priv(struct Scsi_Host
*shost
)
728 return (void *)shost
->hostdata
;
731 int scsi_is_host_device(const struct device
*);
733 static inline struct Scsi_Host
*dev_to_shost(struct device
*dev
)
735 while (!scsi_is_host_device(dev
)) {
740 return container_of(dev
, struct Scsi_Host
, shost_gendev
);
743 static inline int scsi_host_in_recovery(struct Scsi_Host
*shost
)
745 return shost
->shost_state
== SHOST_RECOVERY
||
746 shost
->shost_state
== SHOST_CANCEL_RECOVERY
||
747 shost
->shost_state
== SHOST_DEL_RECOVERY
||
748 shost
->tmf_in_progress
;
751 extern int scsi_queue_work(struct Scsi_Host
*, struct work_struct
*);
752 extern void scsi_flush_work(struct Scsi_Host
*);
754 extern struct Scsi_Host
*scsi_host_alloc(struct scsi_host_template
*, int);
755 extern int __must_check
scsi_add_host_with_dma(struct Scsi_Host
*,
758 extern void scsi_scan_host(struct Scsi_Host
*);
759 extern void scsi_rescan_device(struct device
*);
760 extern void scsi_remove_host(struct Scsi_Host
*);
761 extern struct Scsi_Host
*scsi_host_get(struct Scsi_Host
*);
762 extern int scsi_host_busy(struct Scsi_Host
*shost
);
763 extern void scsi_host_put(struct Scsi_Host
*t
);
764 extern struct Scsi_Host
*scsi_host_lookup(unsigned short);
765 extern const char *scsi_host_state_name(enum scsi_host_state
);
766 extern void scsi_host_complete_all_commands(struct Scsi_Host
*shost
,
767 enum scsi_host_status status
);
769 static inline int __must_check
scsi_add_host(struct Scsi_Host
*host
,
772 return scsi_add_host_with_dma(host
, dev
, dev
);
775 static inline struct device
*scsi_get_device(struct Scsi_Host
*shost
)
777 return shost
->shost_gendev
.parent
;
781 * scsi_host_scan_allowed - Is scanning of this host allowed
782 * @shost: Pointer to Scsi_Host.
784 static inline int scsi_host_scan_allowed(struct Scsi_Host
*shost
)
786 return shost
->shost_state
== SHOST_RUNNING
||
787 shost
->shost_state
== SHOST_RECOVERY
;
790 extern void scsi_unblock_requests(struct Scsi_Host
*);
791 extern void scsi_block_requests(struct Scsi_Host
*);
792 extern int scsi_host_block(struct Scsi_Host
*shost
);
793 extern int scsi_host_unblock(struct Scsi_Host
*shost
, int new_state
);
795 void scsi_host_busy_iter(struct Scsi_Host
*,
796 bool (*fn
)(struct scsi_cmnd
*, void *, bool), void *priv
);
798 struct class_container
;
801 * These two functions are used to allocate and free a pseudo device
802 * which will connect to the host adapter itself rather than any
803 * physical device. You must deallocate when you are done with the
804 * thing. This physical pseudo-device isn't real and won't be available
805 * from any high-level drivers.
807 extern void scsi_free_host_dev(struct scsi_device
*);
808 extern struct scsi_device
*scsi_get_host_dev(struct Scsi_Host
*);
811 * DIF defines the exchange of protection information between
812 * initiator and SBC block device.
814 * DIX defines the exchange of protection information between OS and
817 enum scsi_host_prot_capabilities
{
818 SHOST_DIF_TYPE1_PROTECTION
= 1 << 0, /* T10 DIF Type 1 */
819 SHOST_DIF_TYPE2_PROTECTION
= 1 << 1, /* T10 DIF Type 2 */
820 SHOST_DIF_TYPE3_PROTECTION
= 1 << 2, /* T10 DIF Type 3 */
822 SHOST_DIX_TYPE0_PROTECTION
= 1 << 3, /* DIX between OS and HBA only */
823 SHOST_DIX_TYPE1_PROTECTION
= 1 << 4, /* DIX with DIF Type 1 */
824 SHOST_DIX_TYPE2_PROTECTION
= 1 << 5, /* DIX with DIF Type 2 */
825 SHOST_DIX_TYPE3_PROTECTION
= 1 << 6, /* DIX with DIF Type 3 */
829 * SCSI hosts which support the Data Integrity Extensions must
830 * indicate their capabilities by setting the prot_capabilities using
833 static inline void scsi_host_set_prot(struct Scsi_Host
*shost
, unsigned int mask
)
835 shost
->prot_capabilities
= mask
;
838 static inline unsigned int scsi_host_get_prot(struct Scsi_Host
*shost
)
840 return shost
->prot_capabilities
;
843 static inline int scsi_host_prot_dma(struct Scsi_Host
*shost
)
845 return shost
->prot_capabilities
>= SHOST_DIX_TYPE0_PROTECTION
;
848 static inline unsigned int scsi_host_dif_capable(struct Scsi_Host
*shost
, unsigned int target_type
)
850 static unsigned char cap
[] = { 0,
851 SHOST_DIF_TYPE1_PROTECTION
,
852 SHOST_DIF_TYPE2_PROTECTION
,
853 SHOST_DIF_TYPE3_PROTECTION
};
855 if (target_type
>= ARRAY_SIZE(cap
))
858 return shost
->prot_capabilities
& cap
[target_type
] ? target_type
: 0;
861 static inline unsigned int scsi_host_dix_capable(struct Scsi_Host
*shost
, unsigned int target_type
)
863 #if defined(CONFIG_BLK_DEV_INTEGRITY)
864 static unsigned char cap
[] = { SHOST_DIX_TYPE0_PROTECTION
,
865 SHOST_DIX_TYPE1_PROTECTION
,
866 SHOST_DIX_TYPE2_PROTECTION
,
867 SHOST_DIX_TYPE3_PROTECTION
};
869 if (target_type
>= ARRAY_SIZE(cap
))
872 return shost
->prot_capabilities
& cap
[target_type
];
878 * All DIX-capable initiators must support the T10-mandated CRC
879 * checksum. Controllers can optionally implement the IP checksum
880 * scheme which has much lower impact on system performance. Note
881 * that the main rationale for the checksum is to match integrity
882 * metadata with data. Detecting bit errors are a job for ECC memory
886 enum scsi_host_guard_type
{
887 SHOST_DIX_GUARD_CRC
= 1 << 0,
888 SHOST_DIX_GUARD_IP
= 1 << 1,
891 static inline void scsi_host_set_guard(struct Scsi_Host
*shost
, unsigned char type
)
893 shost
->prot_guard_type
= type
;
896 static inline unsigned char scsi_host_get_guard(struct Scsi_Host
*shost
)
898 return shost
->prot_guard_type
;
901 extern int scsi_host_set_state(struct Scsi_Host
*, enum scsi_host_state
);
903 #endif /* _SCSI_SCSI_HOST_H */