1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef _SCSI_SCSI_HOST_H
3#define _SCSI_SCSI_HOST_H
4
5#include <linux/device.h>
6#include <linux/list.h>
7#include <linux/types.h>
8#include <linux/workqueue.h>
9#include <linux/mutex.h>
10#include <linux/seq_file.h>
11#include <linux/blk-mq.h>
12#include <scsi/scsi.h>
13
14struct block_device;
15struct completion;
16struct module;
17struct scsi_cmnd;
18struct scsi_device;
19struct scsi_host_cmd_pool;
20struct scsi_target;
21struct Scsi_Host;
22struct scsi_host_cmd_pool;
23struct scsi_transport_template;
24
25
26#define SG_ALL	SG_CHUNK_SIZE
27
28#define MODE_UNKNOWN 0x00
29#define MODE_INITIATOR 0x01
30#define MODE_TARGET 0x02
31
32struct scsi_host_template {
33	struct module *module;
34	const char *name;
35
36	/*
37	 * The info function will return whatever useful information the
38	 * developer sees fit.  If not provided, then the name field will
39	 * be used instead.
40	 *
41	 * Status: OPTIONAL
42	 */
43	const char *(* info)(struct Scsi_Host *);
44
45	/*
46	 * Ioctl interface
47	 *
48	 * Status: OPTIONAL
49	 */
50	int (*ioctl)(struct scsi_device *dev, unsigned int cmd,
51		     void __user *arg);
52
53
54#ifdef CONFIG_COMPAT
55	/*
56	 * Compat handler. Handle 32bit ABI.
57	 * When unknown ioctl is passed return -ENOIOCTLCMD.
58	 *
59	 * Status: OPTIONAL
60	 */
61	int (*compat_ioctl)(struct scsi_device *dev, unsigned int cmd,
62			    void __user *arg);
63#endif
64
65	int (*init_cmd_priv)(struct Scsi_Host *shost, struct scsi_cmnd *cmd);
66	int (*exit_cmd_priv)(struct Scsi_Host *shost, struct scsi_cmnd *cmd);
67
68	/*
69	 * The queuecommand function is used to queue up a scsi
70	 * command block to the LLDD.  When the driver finished
71	 * processing the command the done callback is invoked.
72	 *
73	 * If queuecommand returns 0, then the driver has accepted the
74	 * command.  It must also push it to the HBA if the scsi_cmnd
75	 * flag SCMD_LAST is set, or if the driver does not implement
76	 * commit_rqs.  The done() function must be called on the command
77	 * when the driver has finished with it. (you may call done on the
78	 * command before queuecommand returns, but in this case you
79	 * *must* return 0 from queuecommand).
80	 *
81	 * Queuecommand may also reject the command, in which case it may
82	 * not touch the command and must not call done() for it.
83	 *
84	 * There are two possible rejection returns:
85	 *
86	 *   SCSI_MLQUEUE_DEVICE_BUSY: Block this device temporarily, but
87	 *   allow commands to other devices serviced by this host.
88	 *
89	 *   SCSI_MLQUEUE_HOST_BUSY: Block all devices served by this
90	 *   host temporarily.
91	 *
92         * For compatibility, any other non-zero return is treated the
93         * same as SCSI_MLQUEUE_HOST_BUSY.
94	 *
95	 * NOTE: "temporarily" means either until the next command for#
96	 * this device/host completes, or a period of time determined by
97	 * I/O pressure in the system if there are no other outstanding
98	 * commands.
99	 *
100	 * STATUS: REQUIRED
101	 */
102	int (* queuecommand)(struct Scsi_Host *, struct scsi_cmnd *);
103
104	/*
105	 * The commit_rqs function is used to trigger a hardware
106	 * doorbell after some requests have been queued with
107	 * queuecommand, when an error is encountered before sending
108	 * the request with SCMD_LAST set.
109	 *
110	 * STATUS: OPTIONAL
111	 */
112	void (*commit_rqs)(struct Scsi_Host *, u16);
113
114	/*
115	 * This is an error handling strategy routine.  You don't need to
116	 * define one of these if you don't want to - there is a default
117	 * routine that is present that should work in most cases.  For those
118	 * driver authors that have the inclination and ability to write their
119	 * own strategy routine, this is where it is specified.  Note - the
120	 * strategy routine is *ALWAYS* run in the context of the kernel eh
121	 * thread.  Thus you are guaranteed to *NOT* be in an interrupt
122	 * handler when you execute this, and you are also guaranteed to
123	 * *NOT* have any other commands being queued while you are in the
124	 * strategy routine. When you return from this function, operations
125	 * return to normal.
126	 *
127	 * See scsi_error.c scsi_unjam_host for additional comments about
128	 * what this function should and should not be attempting to do.
129	 *
130	 * Status: REQUIRED	(at least one of them)
131	 */
132	int (* eh_abort_handler)(struct scsi_cmnd *);
133	int (* eh_device_reset_handler)(struct scsi_cmnd *);
134	int (* eh_target_reset_handler)(struct scsi_cmnd *);
135	int (* eh_bus_reset_handler)(struct scsi_cmnd *);
136	int (* eh_host_reset_handler)(struct scsi_cmnd *);
137
138	/*
139	 * Before the mid layer attempts to scan for a new device where none
140	 * currently exists, it will call this entry in your driver.  Should
141	 * your driver need to allocate any structs or perform any other init
142	 * items in order to send commands to a currently unused target/lun
143	 * combo, then this is where you can perform those allocations.  This
144	 * is specifically so that drivers won't have to perform any kind of
145	 * "is this a new device" checks in their queuecommand routine,
146	 * thereby making the hot path a bit quicker.
147	 *
148	 * Return values: 0 on success, non-0 on failure
149	 *
150	 * Deallocation:  If we didn't find any devices at this ID, you will
151	 * get an immediate call to slave_destroy().  If we find something
152	 * here then you will get a call to slave_configure(), then the
153	 * device will be used for however long it is kept around, then when
154	 * the device is removed from the system (or * possibly at reboot
155	 * time), you will then get a call to slave_destroy().  This is
156	 * assuming you implement slave_configure and slave_destroy.
157	 * However, if you allocate memory and hang it off the device struct,
158	 * then you must implement the slave_destroy() routine at a minimum
159	 * in order to avoid leaking memory
160	 * each time a device is tore down.
161	 *
162	 * Status: OPTIONAL
163	 */
164	int (* slave_alloc)(struct scsi_device *);
165
166	/*
167	 * Once the device has responded to an INQUIRY and we know the
168	 * device is online, we call into the low level driver with the
169	 * struct scsi_device *.  If the low level device driver implements
170	 * this function, it *must* perform the task of setting the queue
171	 * depth on the device.  All other tasks are optional and depend
172	 * on what the driver supports and various implementation details.
173	 *
174	 * Things currently recommended to be handled at this time include:
175	 *
176	 * 1.  Setting the device queue depth.  Proper setting of this is
177	 *     described in the comments for scsi_change_queue_depth.
178	 * 2.  Determining if the device supports the various synchronous
179	 *     negotiation protocols.  The device struct will already have
180	 *     responded to INQUIRY and the results of the standard items
181	 *     will have been shoved into the various device flag bits, eg.
182	 *     device->sdtr will be true if the device supports SDTR messages.
183	 * 3.  Allocating command structs that the device will need.
184	 * 4.  Setting the default timeout on this device (if needed).
185	 * 5.  Anything else the low level driver might want to do on a device
186	 *     specific setup basis...
187	 * 6.  Return 0 on success, non-0 on error.  The device will be marked
188	 *     as offline on error so that no access will occur.  If you return
189	 *     non-0, your slave_destroy routine will never get called for this
190	 *     device, so don't leave any loose memory hanging around, clean
191	 *     up after yourself before returning non-0
192	 *
193	 * Status: OPTIONAL
194	 */
195	int (* slave_configure)(struct scsi_device *);
196
197	/*
198	 * Immediately prior to deallocating the device and after all activity
199	 * has ceased the mid layer calls this point so that the low level
200	 * driver may completely detach itself from the scsi device and vice
201	 * versa.  The low level driver is responsible for freeing any memory
202	 * it allocated in the slave_alloc or slave_configure calls.
203	 *
204	 * Status: OPTIONAL
205	 */
206	void (* slave_destroy)(struct scsi_device *);
207
208	/*
209	 * Before the mid layer attempts to scan for a new device attached
210	 * to a target where no target currently exists, it will call this
211	 * entry in your driver.  Should your driver need to allocate any
212	 * structs or perform any other init items in order to send commands
213	 * to a currently unused target, then this is where you can perform
214	 * those allocations.
215	 *
216	 * Return values: 0 on success, non-0 on failure
217	 *
218	 * Status: OPTIONAL
219	 */
220	int (* target_alloc)(struct scsi_target *);
221
222	/*
223	 * Immediately prior to deallocating the target structure, and
224	 * after all activity to attached scsi devices has ceased, the
225	 * midlayer calls this point so that the driver may deallocate
226	 * and terminate any references to the target.
227	 *
228	 * Status: OPTIONAL
229	 */
230	void (* target_destroy)(struct scsi_target *);
231
232	/*
233	 * If a host has the ability to discover targets on its own instead
234	 * of scanning the entire bus, it can fill in this function and
235	 * call scsi_scan_host().  This function will be called periodically
236	 * until it returns 1 with the scsi_host and the elapsed time of
237	 * the scan in jiffies.
238	 *
239	 * Status: OPTIONAL
240	 */
241	int (* scan_finished)(struct Scsi_Host *, unsigned long);
242
243	/*
244	 * If the host wants to be called before the scan starts, but
245	 * after the midlayer has set up ready for the scan, it can fill
246	 * in this function.
247	 *
248	 * Status: OPTIONAL
249	 */
250	void (* scan_start)(struct Scsi_Host *);
251
252	/*
253	 * Fill in this function to allow the queue depth of this host
254	 * to be changeable (on a per device basis).  Returns either
255	 * the current queue depth setting (may be different from what
256	 * was passed in) or an error.  An error should only be
257	 * returned if the requested depth is legal but the driver was
258	 * unable to set it.  If the requested depth is illegal, the
259	 * driver should set and return the closest legal queue depth.
260	 *
261	 * Status: OPTIONAL
262	 */
263	int (* change_queue_depth)(struct scsi_device *, int);
264
265	/*
266	 * This functions lets the driver expose the queue mapping
267	 * to the block layer.
268	 *
269	 * Status: OPTIONAL
270	 */
271	int (* map_queues)(struct Scsi_Host *shost);
272
273	/*
274	 * Check if scatterlists need to be padded for DMA draining.
275	 *
276	 * Status: OPTIONAL
277	 */
278	bool (* dma_need_drain)(struct request *rq);
279
280	/*
281	 * This function determines the BIOS parameters for a given
282	 * harddisk.  These tend to be numbers that are made up by
283	 * the host adapter.  Parameters:
284	 * size, device, list (heads, sectors, cylinders)
285	 *
286	 * Status: OPTIONAL
287	 */
288	int (* bios_param)(struct scsi_device *, struct block_device *,
289			sector_t, int []);
290
291	/*
292	 * This function is called when one or more partitions on the
293	 * device reach beyond the end of the device.
294	 *
295	 * Status: OPTIONAL
296	 */
297	void (*unlock_native_capacity)(struct scsi_device *);
298
299	/*
300	 * Can be used to export driver statistics and other infos to the
301	 * world outside the kernel ie. userspace and it also provides an
302	 * interface to feed the driver with information.
303	 *
304	 * Status: OBSOLETE
305	 */
306	int (*show_info)(struct seq_file *, struct Scsi_Host *);
307	int (*write_info)(struct Scsi_Host *, char *, int);
308
309	/*
310	 * This is an optional routine that allows the transport to become
311	 * involved when a scsi io timer fires. The return value tells the
312	 * timer routine how to finish the io timeout handling.
313	 *
314	 * Status: OPTIONAL
315	 */
316	enum blk_eh_timer_return (*eh_timed_out)(struct scsi_cmnd *);
317
318	/* This is an optional routine that allows transport to initiate
319	 * LLD adapter or firmware reset using sysfs attribute.
320	 *
321	 * Return values: 0 on success, -ve value on failure.
322	 *
323	 * Status: OPTIONAL
324	 */
325
326	int (*host_reset)(struct Scsi_Host *shost, int reset_type);
327#define SCSI_ADAPTER_RESET	1
328#define SCSI_FIRMWARE_RESET	2
329
330
331	/*
332	 * Name of proc directory
333	 */
334	const char *proc_name;
335
336	/*
337	 * Used to store the procfs directory if a driver implements the
338	 * show_info method.
339	 */
340	struct proc_dir_entry *proc_dir;
341
342	/*
343	 * This determines if we will use a non-interrupt driven
344	 * or an interrupt driven scheme.  It is set to the maximum number
345	 * of simultaneous commands a single hw queue in HBA will accept.
346	 */
347	int can_queue;
348
349	/*
350	 * In many instances, especially where disconnect / reconnect are
351	 * supported, our host also has an ID on the SCSI bus.  If this is
352	 * the case, then it must be reserved.  Please set this_id to -1 if
353	 * your setup is in single initiator mode, and the host lacks an
354	 * ID.
355	 */
356	int this_id;
357
358	/*
359	 * This determines the degree to which the host adapter is capable
360	 * of scatter-gather.
361	 */
362	unsigned short sg_tablesize;
363	unsigned short sg_prot_tablesize;
364
365	/*
366	 * Set this if the host adapter has limitations beside segment count.
367	 */
368	unsigned int max_sectors;
369
370	/*
371	 * Maximum size in bytes of a single segment.
372	 */
373	unsigned int max_segment_size;
374
375	/*
376	 * DMA scatter gather segment boundary limit. A segment crossing this
377	 * boundary will be split in two.
378	 */
379	unsigned long dma_boundary;
380
381	unsigned long virt_boundary_mask;
382
383	/*
384	 * This specifies "machine infinity" for host templates which don't
385	 * limit the transfer size.  Note this limit represents an absolute
386	 * maximum, and may be over the transfer limits allowed for
387	 * individual devices (e.g. 256 for SCSI-1).
388	 */
389#define SCSI_DEFAULT_MAX_SECTORS	1024
390
391	/*
392	 * True if this host adapter can make good use of linked commands.
393	 * This will allow more than one command to be queued to a given
394	 * unit on a given host.  Set this to the maximum number of command
395	 * blocks to be provided for each device.  Set this to 1 for one
396	 * command block per lun, 2 for two, etc.  Do not set this to 0.
397	 * You should make sure that the host adapter will do the right thing
398	 * before you try setting this above 1.
399	 */
400	short cmd_per_lun;
401
402	/*
403	 * present contains counter indicating how many boards of this
404	 * type were found when we did the scan.
405	 */
406	unsigned char present;
407
408	/* If use block layer to manage tags, this is tag allocation policy */
409	int tag_alloc_policy;
410
411	/*
412	 * Track QUEUE_FULL events and reduce queue depth on demand.
413	 */
414	unsigned track_queue_depth:1;
415
416	/*
417	 * This specifies the mode that a LLD supports.
418	 */
419	unsigned supported_mode:2;
420
421	/*
422	 * True if this host adapter uses unchecked DMA onto an ISA bus.
423	 */
424	unsigned unchecked_isa_dma:1;
425
426	/*
427	 * True for emulated SCSI host adapters (e.g. ATAPI).
428	 */
429	unsigned emulated:1;
430
431	/*
432	 * True if the low-level driver performs its own reset-settle delays.
433	 */
434	unsigned skip_settle_delay:1;
435
436	/* True if the controller does not support WRITE SAME */
437	unsigned no_write_same:1;
438
439	/* True if the host uses host-wide tagspace */
440	unsigned host_tagset:1;
441
442	/*
443	 * Countdown for host blocking with no commands outstanding.
444	 */
445	unsigned int max_host_blocked;
446
447	/*
448	 * Default value for the blocking.  If the queue is empty,
449	 * host_blocked counts down in the request_fn until it restarts
450	 * host operations as zero is reached.
451	 *
452	 * FIXME: This should probably be a value in the template
453	 */
454#define SCSI_DEFAULT_HOST_BLOCKED	7
455
456	/*
457	 * Pointer to the sysfs class properties for this host, NULL terminated.
458	 */
459	struct device_attribute **shost_attrs;
460
461	/*
462	 * Pointer to the SCSI device properties for this host, NULL terminated.
463	 */
464	struct device_attribute **sdev_attrs;
465
466	/*
467	 * Pointer to the SCSI device attribute groups for this host,
468	 * NULL terminated.
469	 */
470	const struct attribute_group **sdev_groups;
471
472	/*
473	 * Vendor Identifier associated with the host
474	 *
475	 * Note: When specifying vendor_id, be sure to read the
476	 *   Vendor Type and ID formatting requirements specified in
477	 *   scsi_netlink.h
478	 */
479	u64 vendor_id;
480
481	/*
482	 * Additional per-command data allocated for the driver.
483	 */
484	unsigned int cmd_size;
485	struct scsi_host_cmd_pool *cmd_pool;
486
487	/* Delay for runtime autosuspend */
488	int rpm_autosuspend_delay;
489};
490
491/*
492 * Temporary #define for host lock push down. Can be removed when all
493 * drivers have been updated to take advantage of unlocked
494 * queuecommand.
495 *
496 */
497#define DEF_SCSI_QCMD(func_name) \
498	int func_name(struct Scsi_Host *shost, struct scsi_cmnd *cmd)	\
499	{								\
500		unsigned long irq_flags;				\
501		int rc;							\
502		spin_lock_irqsave(shost->host_lock, irq_flags);		\
503		rc = func_name##_lck (cmd, cmd->scsi_done);			\
504		spin_unlock_irqrestore(shost->host_lock, irq_flags);	\
505		return rc;						\
506	}
507
508
509/*
510 * shost state: If you alter this, you also need to alter scsi_sysfs.c
511 * (for the ascii descriptions) and the state model enforcer:
512 * scsi_host_set_state()
513 */
514enum scsi_host_state {
515	SHOST_CREATED = 1,
516	SHOST_RUNNING,
517	SHOST_CANCEL,
518	SHOST_DEL,
519	SHOST_RECOVERY,
520	SHOST_CANCEL_RECOVERY,
521	SHOST_DEL_RECOVERY,
522};
523
524struct Scsi_Host {
525	/*
526	 * __devices is protected by the host_lock, but you should
527	 * usually use scsi_device_lookup / shost_for_each_device
528	 * to access it and don't care about locking yourself.
529	 * In the rare case of being in irq context you can use
530	 * their __ prefixed variants with the lock held. NEVER
531	 * access this list directly from a driver.
532	 */
533	struct list_head	__devices;
534	struct list_head	__targets;
535
536	struct list_head	starved_list;
537
538	spinlock_t		default_lock;
539	spinlock_t		*host_lock;
540
541	struct mutex		scan_mutex;/* serialize scanning activity */
542
543	struct list_head	eh_cmd_q;
544	struct task_struct    * ehandler;  /* Error recovery thread. */
545	struct completion     * eh_action; /* Wait for specific actions on the
546					      host. */
547	wait_queue_head_t       host_wait;
548	struct scsi_host_template *hostt;
549	struct scsi_transport_template *transportt;
550
551	/* Area to keep a shared tag map */
552	struct blk_mq_tag_set	tag_set;
553
554	atomic_t host_blocked;
555
556	unsigned int host_failed;	   /* commands that failed.
557					      protected by host_lock */
558	unsigned int host_eh_scheduled;    /* EH scheduled without command */
559
560	unsigned int host_no;  /* Used for IOCTL_GET_IDLUN, /proc/scsi et al. */
561
562	/* next two fields are used to bound the time spent in error handling */
563	int eh_deadline;
564	unsigned long last_reset;
565
566
567	/*
568	 * These three parameters can be used to allow for wide scsi,
569	 * and for host adapters that support multiple busses
570	 * The last two should be set to 1 more than the actual max id
571	 * or lun (e.g. 8 for SCSI parallel systems).
572	 */
573	unsigned int max_channel;
574	unsigned int max_id;
575	u64 max_lun;
576
577	/*
578	 * This is a unique identifier that must be assigned so that we
579	 * have some way of identifying each detected host adapter properly
580	 * and uniquely.  For hosts that do not support more than one card
581	 * in the system at one time, this does not need to be set.  It is
582	 * initialized to 0 in scsi_register.
583	 */
584	unsigned int unique_id;
585
586	/*
587	 * The maximum length of SCSI commands that this host can accept.
588	 * Probably 12 for most host adapters, but could be 16 for others.
589	 * or 260 if the driver supports variable length cdbs.
590	 * For drivers that don't set this field, a value of 12 is
591	 * assumed.
592	 */
593	unsigned short max_cmd_len;
594
595	int this_id;
596	int can_queue;
597	short cmd_per_lun;
598	short unsigned int sg_tablesize;
599	short unsigned int sg_prot_tablesize;
600	unsigned int max_sectors;
601	unsigned int max_segment_size;
602	unsigned long dma_boundary;
603	unsigned long virt_boundary_mask;
604	/*
605	 * In scsi-mq mode, the number of hardware queues supported by the LLD.
606	 *
607	 * Note: it is assumed that each hardware queue has a queue depth of
608	 * can_queue. In other words, the total queue depth per host
609	 * is nr_hw_queues * can_queue. However, for when host_tagset is set,
610	 * the total queue depth is can_queue.
611	 */
612	unsigned nr_hw_queues;
613	unsigned active_mode:2;
614	unsigned unchecked_isa_dma:1;
615
616	/*
617	 * Host has requested that no further requests come through for the
618	 * time being.
619	 */
620	unsigned host_self_blocked:1;
621
622	/*
623	 * Host uses correct SCSI ordering not PC ordering. The bit is
624	 * set for the minority of drivers whose authors actually read
625	 * the spec ;).
626	 */
627	unsigned reverse_ordering:1;
628
629	/* Task mgmt function in progress */
630	unsigned tmf_in_progress:1;
631
632	/* Asynchronous scan in progress */
633	unsigned async_scan:1;
634
635	/* Don't resume host in EH */
636	unsigned eh_noresume:1;
637
638	/* The controller does not support WRITE SAME */
639	unsigned no_write_same:1;
640
641	/* True if the host uses host-wide tagspace */
642	unsigned host_tagset:1;
643
644	/* Host responded with short (<36 bytes) INQUIRY result */
645	unsigned short_inquiry:1;
646
647	/* The transport requires the LUN bits NOT to be stored in CDB[1] */
648	unsigned no_scsi2_lun_in_cdb:1;
649
650	/*
651	 * Optional work queue to be utilized by the transport
652	 */
653	char work_q_name[20];
654	struct workqueue_struct *work_q;
655
656	/*
657	 * Task management function work queue
658	 */
659	struct workqueue_struct *tmf_work_q;
660
661	/*
662	 * Value host_blocked counts down from
663	 */
664	unsigned int max_host_blocked;
665
666	/* Protection Information */
667	unsigned int prot_capabilities;
668	unsigned char prot_guard_type;
669
670	/* legacy crap */
671	unsigned long base;
672	unsigned long io_port;
673	unsigned char n_io_port;
674	unsigned char dma_channel;
675	unsigned int  irq;
676
677
678	enum scsi_host_state shost_state;
679
680	/* ldm bits */
681	struct device		shost_gendev, shost_dev;
682
683	/*
684	 * Points to the transport data (if any) which is allocated
685	 * separately
686	 */
687	void *shost_data;
688
689	/*
690	 * Points to the physical bus device we'd use to do DMA
691	 * Needed just in case we have virtual hosts.
692	 */
693	struct device *dma_dev;
694
695	/*
696	 * We should ensure that this is aligned, both for better performance
697	 * and also because some compilers (m68k) don't automatically force
698	 * alignment to a long boundary.
699	 */
700	unsigned long hostdata[]  /* Used for storage of host specific stuff */
701		__attribute__ ((aligned (sizeof(unsigned long))));
702};
703
704#define		class_to_shost(d)	\
705	container_of(d, struct Scsi_Host, shost_dev)
706
707#define shost_printk(prefix, shost, fmt, a...)	\
708	dev_printk(prefix, &(shost)->shost_gendev, fmt, ##a)
709
710static inline void *shost_priv(struct Scsi_Host *shost)
711{
712	return (void *)shost->hostdata;
713}
714
715int scsi_is_host_device(const struct device *);
716
717static inline struct Scsi_Host *dev_to_shost(struct device *dev)
718{
719	while (!scsi_is_host_device(dev)) {
720		if (!dev->parent)
721			return NULL;
722		dev = dev->parent;
723	}
724	return container_of(dev, struct Scsi_Host, shost_gendev);
725}
726
727static inline int scsi_host_in_recovery(struct Scsi_Host *shost)
728{
729	return shost->shost_state == SHOST_RECOVERY ||
730		shost->shost_state == SHOST_CANCEL_RECOVERY ||
731		shost->shost_state == SHOST_DEL_RECOVERY ||
732		shost->tmf_in_progress;
733}
734
735extern int scsi_queue_work(struct Scsi_Host *, struct work_struct *);
736extern void scsi_flush_work(struct Scsi_Host *);
737
738extern struct Scsi_Host *scsi_host_alloc(struct scsi_host_template *, int);
739extern int __must_check scsi_add_host_with_dma(struct Scsi_Host *,
740					       struct device *,
741					       struct device *);
742extern void scsi_scan_host(struct Scsi_Host *);
743extern void scsi_rescan_device(struct device *);
744extern void scsi_remove_host(struct Scsi_Host *);
745extern struct Scsi_Host *scsi_host_get(struct Scsi_Host *);
746extern int scsi_host_busy(struct Scsi_Host *shost);
747extern void scsi_host_put(struct Scsi_Host *t);
748extern struct Scsi_Host *scsi_host_lookup(unsigned int hostnum);
749extern const char *scsi_host_state_name(enum scsi_host_state);
750extern void scsi_host_complete_all_commands(struct Scsi_Host *shost,
751					    int status);
752
753static inline int __must_check scsi_add_host(struct Scsi_Host *host,
754					     struct device *dev)
755{
756	return scsi_add_host_with_dma(host, dev, dev);
757}
758
759static inline struct device *scsi_get_device(struct Scsi_Host *shost)
760{
761        return shost->shost_gendev.parent;
762}
763
764/**
765 * scsi_host_scan_allowed - Is scanning of this host allowed
766 * @shost:	Pointer to Scsi_Host.
767 **/
768static inline int scsi_host_scan_allowed(struct Scsi_Host *shost)
769{
770	return shost->shost_state == SHOST_RUNNING ||
771	       shost->shost_state == SHOST_RECOVERY;
772}
773
774extern void scsi_unblock_requests(struct Scsi_Host *);
775extern void scsi_block_requests(struct Scsi_Host *);
776extern int scsi_host_block(struct Scsi_Host *shost);
777extern int scsi_host_unblock(struct Scsi_Host *shost, int new_state);
778
779void scsi_host_busy_iter(struct Scsi_Host *,
780			 bool (*fn)(struct scsi_cmnd *, void *, bool), void *priv);
781
782struct class_container;
783
784/*
785 * These two functions are used to allocate and free a pseudo device
786 * which will connect to the host adapter itself rather than any
787 * physical device.  You must deallocate when you are done with the
788 * thing.  This physical pseudo-device isn't real and won't be available
789 * from any high-level drivers.
790 */
791extern void scsi_free_host_dev(struct scsi_device *);
792extern struct scsi_device *scsi_get_host_dev(struct Scsi_Host *);
793
794/*
795 * DIF defines the exchange of protection information between
796 * initiator and SBC block device.
797 *
798 * DIX defines the exchange of protection information between OS and
799 * initiator.
800 */
801enum scsi_host_prot_capabilities {
802	SHOST_DIF_TYPE1_PROTECTION = 1 << 0, /* T10 DIF Type 1 */
803	SHOST_DIF_TYPE2_PROTECTION = 1 << 1, /* T10 DIF Type 2 */
804	SHOST_DIF_TYPE3_PROTECTION = 1 << 2, /* T10 DIF Type 3 */
805
806	SHOST_DIX_TYPE0_PROTECTION = 1 << 3, /* DIX between OS and HBA only */
807	SHOST_DIX_TYPE1_PROTECTION = 1 << 4, /* DIX with DIF Type 1 */
808	SHOST_DIX_TYPE2_PROTECTION = 1 << 5, /* DIX with DIF Type 2 */
809	SHOST_DIX_TYPE3_PROTECTION = 1 << 6, /* DIX with DIF Type 3 */
810};
811
812/*
813 * SCSI hosts which support the Data Integrity Extensions must
814 * indicate their capabilities by setting the prot_capabilities using
815 * this call.
816 */
817static inline void scsi_host_set_prot(struct Scsi_Host *shost, unsigned int mask)
818{
819	shost->prot_capabilities = mask;
820}
821
822static inline unsigned int scsi_host_get_prot(struct Scsi_Host *shost)
823{
824	return shost->prot_capabilities;
825}
826
827static inline int scsi_host_prot_dma(struct Scsi_Host *shost)
828{
829	return shost->prot_capabilities >= SHOST_DIX_TYPE0_PROTECTION;
830}
831
832static inline unsigned int scsi_host_dif_capable(struct Scsi_Host *shost, unsigned int target_type)
833{
834	static unsigned char cap[] = { 0,
835				       SHOST_DIF_TYPE1_PROTECTION,
836				       SHOST_DIF_TYPE2_PROTECTION,
837				       SHOST_DIF_TYPE3_PROTECTION };
838
839	if (target_type >= ARRAY_SIZE(cap))
840		return 0;
841
842	return shost->prot_capabilities & cap[target_type] ? target_type : 0;
843}
844
845static inline unsigned int scsi_host_dix_capable(struct Scsi_Host *shost, unsigned int target_type)
846{
847#if defined(CONFIG_BLK_DEV_INTEGRITY)
848	static unsigned char cap[] = { SHOST_DIX_TYPE0_PROTECTION,
849				       SHOST_DIX_TYPE1_PROTECTION,
850				       SHOST_DIX_TYPE2_PROTECTION,
851				       SHOST_DIX_TYPE3_PROTECTION };
852
853	if (target_type >= ARRAY_SIZE(cap))
854		return 0;
855
856	return shost->prot_capabilities & cap[target_type];
857#endif
858	return 0;
859}
860
861/*
862 * All DIX-capable initiators must support the T10-mandated CRC
863 * checksum.  Controllers can optionally implement the IP checksum
864 * scheme which has much lower impact on system performance.  Note
865 * that the main rationale for the checksum is to match integrity
866 * metadata with data.  Detecting bit errors are a job for ECC memory
867 * and buses.
868 */
869
870enum scsi_host_guard_type {
871	SHOST_DIX_GUARD_CRC = 1 << 0,
872	SHOST_DIX_GUARD_IP  = 1 << 1,
873};
874
875static inline void scsi_host_set_guard(struct Scsi_Host *shost, unsigned char type)
876{
877	shost->prot_guard_type = type;
878}
879
880static inline unsigned char scsi_host_get_guard(struct Scsi_Host *shost)
881{
882	return shost->prot_guard_type;
883}
884
885extern int scsi_host_set_state(struct Scsi_Host *, enum scsi_host_state);
886
887#endif /* _SCSI_SCSI_HOST_H */
888