Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost
[cris-mirror.git] / include / scsi / scsi_host.h
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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>
14 struct request_queue;
15 struct block_device;
16 struct completion;
17 struct module;
18 struct scsi_cmnd;
19 struct scsi_device;
20 struct scsi_host_cmd_pool;
21 struct scsi_target;
22 struct Scsi_Host;
23 struct scsi_host_cmd_pool;
24 struct scsi_transport_template;
25 struct blk_queue_tags;
29 * The various choices mean:
30 * NONE: Self evident. Host adapter is not capable of scatter-gather.
31 * ALL: Means that the host adapter module can do scatter-gather,
32 * and that there is no limit to the size of the table to which
33 * we scatter/gather data. The value we set here is the maximum
34 * single element sglist. To use chained sglists, the adapter
35 * has to set a value beyond ALL (and correctly use the chain
36 * handling API.
37 * Anything else: Indicates the maximum number of chains that can be
38 * used in one scatter-gather request.
40 #define SG_NONE 0
41 #define SG_ALL SG_CHUNK_SIZE
43 #define MODE_UNKNOWN 0x00
44 #define MODE_INITIATOR 0x01
45 #define MODE_TARGET 0x02
47 #define DISABLE_CLUSTERING 0
48 #define ENABLE_CLUSTERING 1
50 struct scsi_host_template {
51 struct module *module;
52 const char *name;
55 * Used to initialize old-style drivers. For new-style drivers
56 * just perform all work in your module initialization function.
58 * Status: OBSOLETE
60 int (* detect)(struct scsi_host_template *);
63 * Used as unload callback for hosts with old-style drivers.
65 * Status: OBSOLETE
67 int (* release)(struct Scsi_Host *);
70 * The info function will return whatever useful information the
71 * developer sees fit. If not provided, then the name field will
72 * be used instead.
74 * Status: OPTIONAL
76 const char *(* info)(struct Scsi_Host *);
79 * Ioctl interface
81 * Status: OPTIONAL
83 int (* ioctl)(struct scsi_device *dev, int cmd, void __user *arg);
86 #ifdef CONFIG_COMPAT
87 /*
88 * Compat handler. Handle 32bit ABI.
89 * When unknown ioctl is passed return -ENOIOCTLCMD.
91 * Status: OPTIONAL
93 int (* compat_ioctl)(struct scsi_device *dev, int cmd, void __user *arg);
94 #endif
97 * The queuecommand function is used to queue up a scsi
98 * command block to the LLDD. When the driver finished
99 * processing the command the done callback is invoked.
101 * If queuecommand returns 0, then the HBA has accepted the
102 * command. The done() function must be called on the command
103 * when the driver has finished with it. (you may call done on the
104 * command before queuecommand returns, but in this case you
105 * *must* return 0 from queuecommand).
107 * Queuecommand may also reject the command, in which case it may
108 * not touch the command and must not call done() for it.
110 * There are two possible rejection returns:
112 * SCSI_MLQUEUE_DEVICE_BUSY: Block this device temporarily, but
113 * allow commands to other devices serviced by this host.
115 * SCSI_MLQUEUE_HOST_BUSY: Block all devices served by this
116 * host temporarily.
118 * For compatibility, any other non-zero return is treated the
119 * same as SCSI_MLQUEUE_HOST_BUSY.
121 * NOTE: "temporarily" means either until the next command for#
122 * this device/host completes, or a period of time determined by
123 * I/O pressure in the system if there are no other outstanding
124 * commands.
126 * STATUS: REQUIRED
128 int (* queuecommand)(struct Scsi_Host *, struct scsi_cmnd *);
131 * This is an error handling strategy routine. You don't need to
132 * define one of these if you don't want to - there is a default
133 * routine that is present that should work in most cases. For those
134 * driver authors that have the inclination and ability to write their
135 * own strategy routine, this is where it is specified. Note - the
136 * strategy routine is *ALWAYS* run in the context of the kernel eh
137 * thread. Thus you are guaranteed to *NOT* be in an interrupt
138 * handler when you execute this, and you are also guaranteed to
139 * *NOT* have any other commands being queued while you are in the
140 * strategy routine. When you return from this function, operations
141 * return to normal.
143 * See scsi_error.c scsi_unjam_host for additional comments about
144 * what this function should and should not be attempting to do.
146 * Status: REQUIRED (at least one of them)
148 int (* eh_abort_handler)(struct scsi_cmnd *);
149 int (* eh_device_reset_handler)(struct scsi_cmnd *);
150 int (* eh_target_reset_handler)(struct scsi_cmnd *);
151 int (* eh_bus_reset_handler)(struct scsi_cmnd *);
152 int (* eh_host_reset_handler)(struct scsi_cmnd *);
155 * Before the mid layer attempts to scan for a new device where none
156 * currently exists, it will call this entry in your driver. Should
157 * your driver need to allocate any structs or perform any other init
158 * items in order to send commands to a currently unused target/lun
159 * combo, then this is where you can perform those allocations. This
160 * is specifically so that drivers won't have to perform any kind of
161 * "is this a new device" checks in their queuecommand routine,
162 * thereby making the hot path a bit quicker.
164 * Return values: 0 on success, non-0 on failure
166 * Deallocation: If we didn't find any devices at this ID, you will
167 * get an immediate call to slave_destroy(). If we find something
168 * here then you will get a call to slave_configure(), then the
169 * device will be used for however long it is kept around, then when
170 * the device is removed from the system (or * possibly at reboot
171 * time), you will then get a call to slave_destroy(). This is
172 * assuming you implement slave_configure and slave_destroy.
173 * However, if you allocate memory and hang it off the device struct,
174 * then you must implement the slave_destroy() routine at a minimum
175 * in order to avoid leaking memory
176 * each time a device is tore down.
178 * Status: OPTIONAL
180 int (* slave_alloc)(struct scsi_device *);
183 * Once the device has responded to an INQUIRY and we know the
184 * device is online, we call into the low level driver with the
185 * struct scsi_device *. If the low level device driver implements
186 * this function, it *must* perform the task of setting the queue
187 * depth on the device. All other tasks are optional and depend
188 * on what the driver supports and various implementation details.
190 * Things currently recommended to be handled at this time include:
192 * 1. Setting the device queue depth. Proper setting of this is
193 * described in the comments for scsi_change_queue_depth.
194 * 2. Determining if the device supports the various synchronous
195 * negotiation protocols. The device struct will already have
196 * responded to INQUIRY and the results of the standard items
197 * will have been shoved into the various device flag bits, eg.
198 * device->sdtr will be true if the device supports SDTR messages.
199 * 3. Allocating command structs that the device will need.
200 * 4. Setting the default timeout on this device (if needed).
201 * 5. Anything else the low level driver might want to do on a device
202 * specific setup basis...
203 * 6. Return 0 on success, non-0 on error. The device will be marked
204 * as offline on error so that no access will occur. If you return
205 * non-0, your slave_destroy routine will never get called for this
206 * device, so don't leave any loose memory hanging around, clean
207 * up after yourself before returning non-0
209 * Status: OPTIONAL
211 int (* slave_configure)(struct scsi_device *);
214 * Immediately prior to deallocating the device and after all activity
215 * has ceased the mid layer calls this point so that the low level
216 * driver may completely detach itself from the scsi device and vice
217 * versa. The low level driver is responsible for freeing any memory
218 * it allocated in the slave_alloc or slave_configure calls.
220 * Status: OPTIONAL
222 void (* slave_destroy)(struct scsi_device *);
225 * Before the mid layer attempts to scan for a new device attached
226 * to a target where no target currently exists, it will call this
227 * entry in your driver. Should your driver need to allocate any
228 * structs or perform any other init items in order to send commands
229 * to a currently unused target, then this is where you can perform
230 * those allocations.
232 * Return values: 0 on success, non-0 on failure
234 * Status: OPTIONAL
236 int (* target_alloc)(struct scsi_target *);
239 * Immediately prior to deallocating the target structure, and
240 * after all activity to attached scsi devices has ceased, the
241 * midlayer calls this point so that the driver may deallocate
242 * and terminate any references to the target.
244 * Status: OPTIONAL
246 void (* target_destroy)(struct scsi_target *);
249 * If a host has the ability to discover targets on its own instead
250 * of scanning the entire bus, it can fill in this function and
251 * call scsi_scan_host(). This function will be called periodically
252 * until it returns 1 with the scsi_host and the elapsed time of
253 * the scan in jiffies.
255 * Status: OPTIONAL
257 int (* scan_finished)(struct Scsi_Host *, unsigned long);
260 * If the host wants to be called before the scan starts, but
261 * after the midlayer has set up ready for the scan, it can fill
262 * in this function.
264 * Status: OPTIONAL
266 void (* scan_start)(struct Scsi_Host *);
269 * Fill in this function to allow the queue depth of this host
270 * to be changeable (on a per device basis). Returns either
271 * the current queue depth setting (may be different from what
272 * was passed in) or an error. An error should only be
273 * returned if the requested depth is legal but the driver was
274 * unable to set it. If the requested depth is illegal, the
275 * driver should set and return the closest legal queue depth.
277 * Status: OPTIONAL
279 int (* change_queue_depth)(struct scsi_device *, int);
282 * This functions lets the driver expose the queue mapping
283 * to the block layer.
285 * Status: OPTIONAL
287 int (* map_queues)(struct Scsi_Host *shost);
290 * This function determines the BIOS parameters for a given
291 * harddisk. These tend to be numbers that are made up by
292 * the host adapter. Parameters:
293 * size, device, list (heads, sectors, cylinders)
295 * Status: OPTIONAL
297 int (* bios_param)(struct scsi_device *, struct block_device *,
298 sector_t, int []);
301 * This function is called when one or more partitions on the
302 * device reach beyond the end of the device.
304 * Status: OPTIONAL
306 void (*unlock_native_capacity)(struct scsi_device *);
309 * Can be used to export driver statistics and other infos to the
310 * world outside the kernel ie. userspace and it also provides an
311 * interface to feed the driver with information.
313 * Status: OBSOLETE
315 int (*show_info)(struct seq_file *, struct Scsi_Host *);
316 int (*write_info)(struct Scsi_Host *, char *, int);
319 * This is an optional routine that allows the transport to become
320 * involved when a scsi io timer fires. The return value tells the
321 * timer routine how to finish the io timeout handling:
322 * EH_HANDLED: I fixed the error, please complete the command
323 * EH_RESET_TIMER: I need more time, reset the timer and
324 * begin counting again
325 * EH_NOT_HANDLED Begin normal error recovery
327 * Status: OPTIONAL
329 enum blk_eh_timer_return (*eh_timed_out)(struct scsi_cmnd *);
331 /* This is an optional routine that allows transport to initiate
332 * LLD adapter or firmware reset using sysfs attribute.
334 * Return values: 0 on success, -ve value on failure.
336 * Status: OPTIONAL
339 int (*host_reset)(struct Scsi_Host *shost, int reset_type);
340 #define SCSI_ADAPTER_RESET 1
341 #define SCSI_FIRMWARE_RESET 2
345 * Name of proc directory
347 const char *proc_name;
350 * Used to store the procfs directory if a driver implements the
351 * show_info method.
353 struct proc_dir_entry *proc_dir;
356 * This determines if we will use a non-interrupt driven
357 * or an interrupt driven scheme. It is set to the maximum number
358 * of simultaneous commands a given host adapter will accept.
360 int can_queue;
363 * In many instances, especially where disconnect / reconnect are
364 * supported, our host also has an ID on the SCSI bus. If this is
365 * the case, then it must be reserved. Please set this_id to -1 if
366 * your setup is in single initiator mode, and the host lacks an
367 * ID.
369 int this_id;
372 * This determines the degree to which the host adapter is capable
373 * of scatter-gather.
375 unsigned short sg_tablesize;
376 unsigned short sg_prot_tablesize;
379 * Set this if the host adapter has limitations beside segment count.
381 unsigned int max_sectors;
384 * DMA scatter gather segment boundary limit. A segment crossing this
385 * boundary will be split in two.
387 unsigned long dma_boundary;
390 * This specifies "machine infinity" for host templates which don't
391 * limit the transfer size. Note this limit represents an absolute
392 * maximum, and may be over the transfer limits allowed for
393 * individual devices (e.g. 256 for SCSI-1).
395 #define SCSI_DEFAULT_MAX_SECTORS 1024
398 * True if this host adapter can make good use of linked commands.
399 * This will allow more than one command to be queued to a given
400 * unit on a given host. Set this to the maximum number of command
401 * blocks to be provided for each device. Set this to 1 for one
402 * command block per lun, 2 for two, etc. Do not set this to 0.
403 * You should make sure that the host adapter will do the right thing
404 * before you try setting this above 1.
406 short cmd_per_lun;
409 * present contains counter indicating how many boards of this
410 * type were found when we did the scan.
412 unsigned char present;
414 /* If use block layer to manage tags, this is tag allocation policy */
415 int tag_alloc_policy;
418 * Track QUEUE_FULL events and reduce queue depth on demand.
420 unsigned track_queue_depth:1;
423 * This specifies the mode that a LLD supports.
425 unsigned supported_mode:2;
428 * True if this host adapter uses unchecked DMA onto an ISA bus.
430 unsigned unchecked_isa_dma:1;
433 * True if this host adapter can make good use of clustering.
434 * I originally thought that if the tablesize was large that it
435 * was a waste of CPU cycles to prepare a cluster list, but
436 * it works out that the Buslogic is faster if you use a smaller
437 * number of segments (i.e. use clustering). I guess it is
438 * inefficient.
440 unsigned use_clustering:1;
443 * True for emulated SCSI host adapters (e.g. ATAPI).
445 unsigned emulated:1;
448 * True if the low-level driver performs its own reset-settle delays.
450 unsigned skip_settle_delay:1;
452 /* True if the controller does not support WRITE SAME */
453 unsigned no_write_same:1;
456 * Countdown for host blocking with no commands outstanding.
458 unsigned int max_host_blocked;
461 * Default value for the blocking. If the queue is empty,
462 * host_blocked counts down in the request_fn until it restarts
463 * host operations as zero is reached.
465 * FIXME: This should probably be a value in the template
467 #define SCSI_DEFAULT_HOST_BLOCKED 7
470 * Pointer to the sysfs class properties for this host, NULL terminated.
472 struct device_attribute **shost_attrs;
475 * Pointer to the SCSI device properties for this host, NULL terminated.
477 struct device_attribute **sdev_attrs;
480 * List of hosts per template.
482 * This is only for use by scsi_module.c for legacy templates.
483 * For these access to it is synchronized implicitly by
484 * module_init/module_exit.
486 struct list_head legacy_hosts;
489 * Vendor Identifier associated with the host
491 * Note: When specifying vendor_id, be sure to read the
492 * Vendor Type and ID formatting requirements specified in
493 * scsi_netlink.h
495 u64 vendor_id;
498 * Additional per-command data allocated for the driver.
500 unsigned int cmd_size;
501 struct scsi_host_cmd_pool *cmd_pool;
505 * Temporary #define for host lock push down. Can be removed when all
506 * drivers have been updated to take advantage of unlocked
507 * queuecommand.
510 #define DEF_SCSI_QCMD(func_name) \
511 int func_name(struct Scsi_Host *shost, struct scsi_cmnd *cmd) \
513 unsigned long irq_flags; \
514 int rc; \
515 spin_lock_irqsave(shost->host_lock, irq_flags); \
516 scsi_cmd_get_serial(shost, cmd); \
517 rc = func_name##_lck (cmd, cmd->scsi_done); \
518 spin_unlock_irqrestore(shost->host_lock, irq_flags); \
519 return rc; \
524 * shost state: If you alter this, you also need to alter scsi_sysfs.c
525 * (for the ascii descriptions) and the state model enforcer:
526 * scsi_host_set_state()
528 enum scsi_host_state {
529 SHOST_CREATED = 1,
530 SHOST_RUNNING,
531 SHOST_CANCEL,
532 SHOST_DEL,
533 SHOST_RECOVERY,
534 SHOST_CANCEL_RECOVERY,
535 SHOST_DEL_RECOVERY,
538 struct Scsi_Host {
540 * __devices is protected by the host_lock, but you should
541 * usually use scsi_device_lookup / shost_for_each_device
542 * to access it and don't care about locking yourself.
543 * In the rare case of being in irq context you can use
544 * their __ prefixed variants with the lock held. NEVER
545 * access this list directly from a driver.
547 struct list_head __devices;
548 struct list_head __targets;
550 struct list_head starved_list;
552 spinlock_t default_lock;
553 spinlock_t *host_lock;
555 struct mutex scan_mutex;/* serialize scanning activity */
557 struct list_head eh_cmd_q;
558 struct task_struct * ehandler; /* Error recovery thread. */
559 struct completion * eh_action; /* Wait for specific actions on the
560 host. */
561 wait_queue_head_t host_wait;
562 struct scsi_host_template *hostt;
563 struct scsi_transport_template *transportt;
566 * Area to keep a shared tag map (if needed, will be
567 * NULL if not).
569 union {
570 struct blk_queue_tag *bqt;
571 struct blk_mq_tag_set tag_set;
574 atomic_t host_busy; /* commands actually active on low-level */
575 atomic_t host_blocked;
577 unsigned int host_failed; /* commands that failed.
578 protected by host_lock */
579 unsigned int host_eh_scheduled; /* EH scheduled without command */
581 unsigned int host_no; /* Used for IOCTL_GET_IDLUN, /proc/scsi et al. */
583 /* next two fields are used to bound the time spent in error handling */
584 int eh_deadline;
585 unsigned long last_reset;
589 * These three parameters can be used to allow for wide scsi,
590 * and for host adapters that support multiple busses
591 * The last two should be set to 1 more than the actual max id
592 * or lun (e.g. 8 for SCSI parallel systems).
594 unsigned int max_channel;
595 unsigned int max_id;
596 u64 max_lun;
599 * This is a unique identifier that must be assigned so that we
600 * have some way of identifying each detected host adapter properly
601 * and uniquely. For hosts that do not support more than one card
602 * in the system at one time, this does not need to be set. It is
603 * initialized to 0 in scsi_register.
605 unsigned int unique_id;
608 * The maximum length of SCSI commands that this host can accept.
609 * Probably 12 for most host adapters, but could be 16 for others.
610 * or 260 if the driver supports variable length cdbs.
611 * For drivers that don't set this field, a value of 12 is
612 * assumed.
614 unsigned short max_cmd_len;
616 int this_id;
617 int can_queue;
618 short cmd_per_lun;
619 short unsigned int sg_tablesize;
620 short unsigned int sg_prot_tablesize;
621 unsigned int max_sectors;
622 unsigned long dma_boundary;
624 * In scsi-mq mode, the number of hardware queues supported by the LLD.
626 * Note: it is assumed that each hardware queue has a queue depth of
627 * can_queue. In other words, the total queue depth per host
628 * is nr_hw_queues * can_queue.
630 unsigned nr_hw_queues;
632 * Used to assign serial numbers to the cmds.
633 * Protected by the host lock.
635 unsigned long cmd_serial_number;
637 unsigned active_mode:2;
638 unsigned unchecked_isa_dma:1;
639 unsigned use_clustering:1;
642 * Host has requested that no further requests come through for the
643 * time being.
645 unsigned host_self_blocked:1;
648 * Host uses correct SCSI ordering not PC ordering. The bit is
649 * set for the minority of drivers whose authors actually read
650 * the spec ;).
652 unsigned reverse_ordering:1;
654 /* Task mgmt function in progress */
655 unsigned tmf_in_progress:1;
657 /* Asynchronous scan in progress */
658 unsigned async_scan:1;
660 /* Don't resume host in EH */
661 unsigned eh_noresume:1;
663 /* The controller does not support WRITE SAME */
664 unsigned no_write_same:1;
666 unsigned use_blk_mq:1;
667 unsigned use_cmd_list:1;
669 /* Host responded with short (<36 bytes) INQUIRY result */
670 unsigned short_inquiry:1;
673 * Optional work queue to be utilized by the transport
675 char work_q_name[20];
676 struct workqueue_struct *work_q;
679 * Task management function work queue
681 struct workqueue_struct *tmf_work_q;
683 /* The transport requires the LUN bits NOT to be stored in CDB[1] */
684 unsigned no_scsi2_lun_in_cdb:1;
687 * Value host_blocked counts down from
689 unsigned int max_host_blocked;
691 /* Protection Information */
692 unsigned int prot_capabilities;
693 unsigned char prot_guard_type;
695 /* legacy crap */
696 unsigned long base;
697 unsigned long io_port;
698 unsigned char n_io_port;
699 unsigned char dma_channel;
700 unsigned int irq;
703 enum scsi_host_state shost_state;
705 /* ldm bits */
706 struct device shost_gendev, shost_dev;
709 * List of hosts per template.
711 * This is only for use by scsi_module.c for legacy templates.
712 * For these access to it is synchronized implicitly by
713 * module_init/module_exit.
715 struct list_head sht_legacy_list;
718 * Points to the transport data (if any) which is allocated
719 * separately
721 void *shost_data;
724 * Points to the physical bus device we'd use to do DMA
725 * Needed just in case we have virtual hosts.
727 struct device *dma_dev;
730 * We should ensure that this is aligned, both for better performance
731 * and also because some compilers (m68k) don't automatically force
732 * alignment to a long boundary.
734 unsigned long hostdata[0] /* Used for storage of host specific stuff */
735 __attribute__ ((aligned (sizeof(unsigned long))));
738 #define class_to_shost(d) \
739 container_of(d, struct Scsi_Host, shost_dev)
741 #define shost_printk(prefix, shost, fmt, a...) \
742 dev_printk(prefix, &(shost)->shost_gendev, fmt, ##a)
744 static inline void *shost_priv(struct Scsi_Host *shost)
746 return (void *)shost->hostdata;
749 int scsi_is_host_device(const struct device *);
751 static inline struct Scsi_Host *dev_to_shost(struct device *dev)
753 while (!scsi_is_host_device(dev)) {
754 if (!dev->parent)
755 return NULL;
756 dev = dev->parent;
758 return container_of(dev, struct Scsi_Host, shost_gendev);
761 static inline int scsi_host_in_recovery(struct Scsi_Host *shost)
763 return shost->shost_state == SHOST_RECOVERY ||
764 shost->shost_state == SHOST_CANCEL_RECOVERY ||
765 shost->shost_state == SHOST_DEL_RECOVERY ||
766 shost->tmf_in_progress;
769 static inline bool shost_use_blk_mq(struct Scsi_Host *shost)
771 return shost->use_blk_mq;
774 extern int scsi_queue_work(struct Scsi_Host *, struct work_struct *);
775 extern void scsi_flush_work(struct Scsi_Host *);
777 extern struct Scsi_Host *scsi_host_alloc(struct scsi_host_template *, int);
778 extern int __must_check scsi_add_host_with_dma(struct Scsi_Host *,
779 struct device *,
780 struct device *);
781 extern void scsi_scan_host(struct Scsi_Host *);
782 extern void scsi_rescan_device(struct device *);
783 extern void scsi_remove_host(struct Scsi_Host *);
784 extern struct Scsi_Host *scsi_host_get(struct Scsi_Host *);
785 extern void scsi_host_put(struct Scsi_Host *t);
786 extern struct Scsi_Host *scsi_host_lookup(unsigned short);
787 extern const char *scsi_host_state_name(enum scsi_host_state);
788 extern void scsi_cmd_get_serial(struct Scsi_Host *, struct scsi_cmnd *);
790 static inline int __must_check scsi_add_host(struct Scsi_Host *host,
791 struct device *dev)
793 return scsi_add_host_with_dma(host, dev, dev);
796 static inline struct device *scsi_get_device(struct Scsi_Host *shost)
798 return shost->shost_gendev.parent;
802 * scsi_host_scan_allowed - Is scanning of this host allowed
803 * @shost: Pointer to Scsi_Host.
805 static inline int scsi_host_scan_allowed(struct Scsi_Host *shost)
807 return shost->shost_state == SHOST_RUNNING ||
808 shost->shost_state == SHOST_RECOVERY;
811 extern void scsi_unblock_requests(struct Scsi_Host *);
812 extern void scsi_block_requests(struct Scsi_Host *);
814 struct class_container;
817 * These two functions are used to allocate and free a pseudo device
818 * which will connect to the host adapter itself rather than any
819 * physical device. You must deallocate when you are done with the
820 * thing. This physical pseudo-device isn't real and won't be available
821 * from any high-level drivers.
823 extern void scsi_free_host_dev(struct scsi_device *);
824 extern struct scsi_device *scsi_get_host_dev(struct Scsi_Host *);
827 * DIF defines the exchange of protection information between
828 * initiator and SBC block device.
830 * DIX defines the exchange of protection information between OS and
831 * initiator.
833 enum scsi_host_prot_capabilities {
834 SHOST_DIF_TYPE1_PROTECTION = 1 << 0, /* T10 DIF Type 1 */
835 SHOST_DIF_TYPE2_PROTECTION = 1 << 1, /* T10 DIF Type 2 */
836 SHOST_DIF_TYPE3_PROTECTION = 1 << 2, /* T10 DIF Type 3 */
838 SHOST_DIX_TYPE0_PROTECTION = 1 << 3, /* DIX between OS and HBA only */
839 SHOST_DIX_TYPE1_PROTECTION = 1 << 4, /* DIX with DIF Type 1 */
840 SHOST_DIX_TYPE2_PROTECTION = 1 << 5, /* DIX with DIF Type 2 */
841 SHOST_DIX_TYPE3_PROTECTION = 1 << 6, /* DIX with DIF Type 3 */
845 * SCSI hosts which support the Data Integrity Extensions must
846 * indicate their capabilities by setting the prot_capabilities using
847 * this call.
849 static inline void scsi_host_set_prot(struct Scsi_Host *shost, unsigned int mask)
851 shost->prot_capabilities = mask;
854 static inline unsigned int scsi_host_get_prot(struct Scsi_Host *shost)
856 return shost->prot_capabilities;
859 static inline int scsi_host_prot_dma(struct Scsi_Host *shost)
861 return shost->prot_capabilities >= SHOST_DIX_TYPE0_PROTECTION;
864 static inline unsigned int scsi_host_dif_capable(struct Scsi_Host *shost, unsigned int target_type)
866 static unsigned char cap[] = { 0,
867 SHOST_DIF_TYPE1_PROTECTION,
868 SHOST_DIF_TYPE2_PROTECTION,
869 SHOST_DIF_TYPE3_PROTECTION };
871 if (target_type >= ARRAY_SIZE(cap))
872 return 0;
874 return shost->prot_capabilities & cap[target_type] ? target_type : 0;
877 static inline unsigned int scsi_host_dix_capable(struct Scsi_Host *shost, unsigned int target_type)
879 #if defined(CONFIG_BLK_DEV_INTEGRITY)
880 static unsigned char cap[] = { SHOST_DIX_TYPE0_PROTECTION,
881 SHOST_DIX_TYPE1_PROTECTION,
882 SHOST_DIX_TYPE2_PROTECTION,
883 SHOST_DIX_TYPE3_PROTECTION };
885 if (target_type >= ARRAY_SIZE(cap))
886 return 0;
888 return shost->prot_capabilities & cap[target_type];
889 #endif
890 return 0;
894 * All DIX-capable initiators must support the T10-mandated CRC
895 * checksum. Controllers can optionally implement the IP checksum
896 * scheme which has much lower impact on system performance. Note
897 * that the main rationale for the checksum is to match integrity
898 * metadata with data. Detecting bit errors are a job for ECC memory
899 * and buses.
902 enum scsi_host_guard_type {
903 SHOST_DIX_GUARD_CRC = 1 << 0,
904 SHOST_DIX_GUARD_IP = 1 << 1,
907 static inline void scsi_host_set_guard(struct Scsi_Host *shost, unsigned char type)
909 shost->prot_guard_type = type;
912 static inline unsigned char scsi_host_get_guard(struct Scsi_Host *shost)
914 return shost->prot_guard_type;
917 /* legacy interfaces */
918 extern struct Scsi_Host *scsi_register(struct scsi_host_template *, int);
919 extern void scsi_unregister(struct Scsi_Host *);
920 extern int scsi_host_set_state(struct Scsi_Host *, enum scsi_host_state);
922 #endif /* _SCSI_SCSI_HOST_H */