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Linus Torvalds1da177e2005-04-16 15:20:36 -07001#ifndef _SCSI_SCSI_HOST_H
2#define _SCSI_SCSI_HOST_H
3
4#include <linux/device.h>
5#include <linux/list.h>
6#include <linux/types.h>
7#include <linux/workqueue.h>
Arjan van de Ven0b950672006-01-11 13:16:10 +01008#include <linux/mutex.h>
Al Viro0ffddfb2013-03-30 23:58:05 -04009#include <linux/seq_file.h>
Christoph Hellwigd2852032014-01-17 12:06:53 +010010#include <linux/blk-mq.h>
James Bottomley4660c8e2008-02-10 09:42:46 -060011#include <scsi/scsi.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070012
FUJITA Tomonorib58d9152006-11-16 19:24:10 +090013struct request_queue;
Linus Torvalds1da177e2005-04-16 15:20:36 -070014struct block_device;
Christoph Hellwig7dfdc9a2005-10-31 18:49:52 +010015struct completion;
Linus Torvalds1da177e2005-04-16 15:20:36 -070016struct module;
17struct scsi_cmnd;
18struct scsi_device;
Christoph Hellwig89d9a562014-02-20 14:21:01 -080019struct scsi_host_cmd_pool;
James Bottomleya283bd32005-05-24 12:06:38 -050020struct scsi_target;
Linus Torvalds1da177e2005-04-16 15:20:36 -070021struct Scsi_Host;
22struct scsi_host_cmd_pool;
23struct scsi_transport_template;
James Bottomley86e33a22006-08-30 09:45:51 -040024struct blk_queue_tags;
Linus Torvalds1da177e2005-04-16 15:20:36 -070025
26
27/*
28 * The various choices mean:
29 * NONE: Self evident. Host adapter is not capable of scatter-gather.
30 * ALL: Means that the host adapter module can do scatter-gather,
31 * and that there is no limit to the size of the table to which
James Bottomley4660c8e2008-02-10 09:42:46 -060032 * we scatter/gather data. The value we set here is the maximum
33 * single element sglist. To use chained sglists, the adapter
34 * has to set a value beyond ALL (and correctly use the chain
35 * handling API.
Linus Torvalds1da177e2005-04-16 15:20:36 -070036 * Anything else: Indicates the maximum number of chains that can be
37 * used in one scatter-gather request.
38 */
39#define SG_NONE 0
James Bottomley4660c8e2008-02-10 09:42:46 -060040#define SG_ALL SCSI_MAX_SG_SEGMENTS
Linus Torvalds1da177e2005-04-16 15:20:36 -070041
FUJITA Tomonori5dc2b892007-09-01 02:02:20 +090042#define MODE_UNKNOWN 0x00
43#define MODE_INITIATOR 0x01
44#define MODE_TARGET 0x02
Linus Torvalds1da177e2005-04-16 15:20:36 -070045
46#define DISABLE_CLUSTERING 0
47#define ENABLE_CLUSTERING 1
48
Linus Torvalds1da177e2005-04-16 15:20:36 -070049struct scsi_host_template {
50 struct module *module;
51 const char *name;
52
53 /*
54 * Used to initialize old-style drivers. For new-style drivers
55 * just perform all work in your module initialization function.
56 *
57 * Status: OBSOLETE
58 */
59 int (* detect)(struct scsi_host_template *);
60
61 /*
62 * Used as unload callback for hosts with old-style drivers.
63 *
64 * Status: OBSOLETE
65 */
66 int (* release)(struct Scsi_Host *);
67
68 /*
69 * The info function will return whatever useful information the
70 * developer sees fit. If not provided, then the name field will
71 * be used instead.
72 *
73 * Status: OPTIONAL
74 */
75 const char *(* info)(struct Scsi_Host *);
76
77 /*
78 * Ioctl interface
79 *
80 * Status: OPTIONAL
81 */
82 int (* ioctl)(struct scsi_device *dev, int cmd, void __user *arg);
83
84
85#ifdef CONFIG_COMPAT
86 /*
87 * Compat handler. Handle 32bit ABI.
88 * When unknown ioctl is passed return -ENOIOCTLCMD.
89 *
90 * Status: OPTIONAL
91 */
92 int (* compat_ioctl)(struct scsi_device *dev, int cmd, void __user *arg);
93#endif
94
95 /*
96 * The queuecommand function is used to queue up a scsi
97 * command block to the LLDD. When the driver finished
98 * processing the command the done callback is invoked.
99 *
100 * If queuecommand returns 0, then the HBA has accepted the
101 * command. The done() function must be called on the command
102 * when the driver has finished with it. (you may call done on the
103 * command before queuecommand returns, but in this case you
104 * *must* return 0 from queuecommand).
105 *
106 * Queuecommand may also reject the command, in which case it may
107 * not touch the command and must not call done() for it.
108 *
109 * There are two possible rejection returns:
110 *
111 * SCSI_MLQUEUE_DEVICE_BUSY: Block this device temporarily, but
112 * allow commands to other devices serviced by this host.
113 *
114 * SCSI_MLQUEUE_HOST_BUSY: Block all devices served by this
115 * host temporarily.
116 *
117 * For compatibility, any other non-zero return is treated the
118 * same as SCSI_MLQUEUE_HOST_BUSY.
119 *
120 * NOTE: "temporarily" means either until the next command for#
121 * this device/host completes, or a period of time determined by
122 * I/O pressure in the system if there are no other outstanding
123 * commands.
124 *
125 * STATUS: REQUIRED
126 */
Jeff Garzikf2812332010-11-16 02:10:29 -0500127 int (* queuecommand)(struct Scsi_Host *, struct scsi_cmnd *);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700128
129 /*
130 * This is an error handling strategy routine. You don't need to
131 * define one of these if you don't want to - there is a default
132 * routine that is present that should work in most cases. For those
133 * driver authors that have the inclination and ability to write their
134 * own strategy routine, this is where it is specified. Note - the
135 * strategy routine is *ALWAYS* run in the context of the kernel eh
136 * thread. Thus you are guaranteed to *NOT* be in an interrupt
137 * handler when you execute this, and you are also guaranteed to
138 * *NOT* have any other commands being queued while you are in the
139 * strategy routine. When you return from this function, operations
140 * return to normal.
141 *
142 * See scsi_error.c scsi_unjam_host for additional comments about
143 * what this function should and should not be attempting to do.
144 *
145 * Status: REQUIRED (at least one of them)
146 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700147 int (* eh_abort_handler)(struct scsi_cmnd *);
148 int (* eh_device_reset_handler)(struct scsi_cmnd *);
Mike Christie30bd7df2008-02-29 18:25:19 -0600149 int (* eh_target_reset_handler)(struct scsi_cmnd *);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700150 int (* eh_bus_reset_handler)(struct scsi_cmnd *);
151 int (* eh_host_reset_handler)(struct scsi_cmnd *);
152
153 /*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700154 * Before the mid layer attempts to scan for a new device where none
155 * currently exists, it will call this entry in your driver. Should
156 * your driver need to allocate any structs or perform any other init
157 * items in order to send commands to a currently unused target/lun
158 * combo, then this is where you can perform those allocations. This
159 * is specifically so that drivers won't have to perform any kind of
160 * "is this a new device" checks in their queuecommand routine,
161 * thereby making the hot path a bit quicker.
162 *
163 * Return values: 0 on success, non-0 on failure
164 *
165 * Deallocation: If we didn't find any devices at this ID, you will
166 * get an immediate call to slave_destroy(). If we find something
167 * here then you will get a call to slave_configure(), then the
168 * device will be used for however long it is kept around, then when
169 * the device is removed from the system (or * possibly at reboot
170 * time), you will then get a call to slave_destroy(). This is
171 * assuming you implement slave_configure and slave_destroy.
172 * However, if you allocate memory and hang it off the device struct,
173 * then you must implement the slave_destroy() routine at a minimum
174 * in order to avoid leaking memory
175 * each time a device is tore down.
176 *
177 * Status: OPTIONAL
178 */
179 int (* slave_alloc)(struct scsi_device *);
180
181 /*
182 * Once the device has responded to an INQUIRY and we know the
183 * device is online, we call into the low level driver with the
184 * struct scsi_device *. If the low level device driver implements
185 * this function, it *must* perform the task of setting the queue
186 * depth on the device. All other tasks are optional and depend
187 * on what the driver supports and various implementation details.
188 *
189 * Things currently recommended to be handled at this time include:
190 *
191 * 1. Setting the device queue depth. Proper setting of this is
Christoph Hellwigdb5ed4d2014-11-13 15:08:42 +0100192 * described in the comments for scsi_change_queue_depth.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700193 * 2. Determining if the device supports the various synchronous
194 * negotiation protocols. The device struct will already have
195 * responded to INQUIRY and the results of the standard items
196 * will have been shoved into the various device flag bits, eg.
197 * device->sdtr will be true if the device supports SDTR messages.
198 * 3. Allocating command structs that the device will need.
199 * 4. Setting the default timeout on this device (if needed).
200 * 5. Anything else the low level driver might want to do on a device
201 * specific setup basis...
202 * 6. Return 0 on success, non-0 on error. The device will be marked
203 * as offline on error so that no access will occur. If you return
204 * non-0, your slave_destroy routine will never get called for this
205 * device, so don't leave any loose memory hanging around, clean
206 * up after yourself before returning non-0
207 *
208 * Status: OPTIONAL
209 */
210 int (* slave_configure)(struct scsi_device *);
211
212 /*
213 * Immediately prior to deallocating the device and after all activity
214 * has ceased the mid layer calls this point so that the low level
215 * driver may completely detach itself from the scsi device and vice
216 * versa. The low level driver is responsible for freeing any memory
217 * it allocated in the slave_alloc or slave_configure calls.
218 *
219 * Status: OPTIONAL
220 */
221 void (* slave_destroy)(struct scsi_device *);
222
223 /*
James Bottomleya283bd32005-05-24 12:06:38 -0500224 * Before the mid layer attempts to scan for a new device attached
225 * to a target where no target currently exists, it will call this
226 * entry in your driver. Should your driver need to allocate any
227 * structs or perform any other init items in order to send commands
228 * to a currently unused target, then this is where you can perform
229 * those allocations.
230 *
231 * Return values: 0 on success, non-0 on failure
232 *
233 * Status: OPTIONAL
234 */
235 int (* target_alloc)(struct scsi_target *);
236
237 /*
238 * Immediately prior to deallocating the target structure, and
239 * after all activity to attached scsi devices has ceased, the
240 * midlayer calls this point so that the driver may deallocate
241 * and terminate any references to the target.
242 *
243 * Status: OPTIONAL
244 */
245 void (* target_destroy)(struct scsi_target *);
246
247 /*
Matthew Wilcox1aa8fab2006-11-22 13:24:54 -0700248 * If a host has the ability to discover targets on its own instead
249 * of scanning the entire bus, it can fill in this function and
250 * call scsi_scan_host(). This function will be called periodically
251 * until it returns 1 with the scsi_host and the elapsed time of
252 * the scan in jiffies.
253 *
254 * Status: OPTIONAL
255 */
256 int (* scan_finished)(struct Scsi_Host *, unsigned long);
257
258 /*
259 * If the host wants to be called before the scan starts, but
260 * after the midlayer has set up ready for the scan, it can fill
261 * in this function.
Pavel Machekd850bd32008-02-04 23:53:24 -0800262 *
263 * Status: OPTIONAL
Matthew Wilcox1aa8fab2006-11-22 13:24:54 -0700264 */
265 void (* scan_start)(struct Scsi_Host *);
266
267 /*
Pavel Machekd850bd32008-02-04 23:53:24 -0800268 * Fill in this function to allow the queue depth of this host
269 * to be changeable (on a per device basis). Returns either
Linus Torvalds1da177e2005-04-16 15:20:36 -0700270 * the current queue depth setting (may be different from what
271 * was passed in) or an error. An error should only be
272 * returned if the requested depth is legal but the driver was
273 * unable to set it. If the requested depth is illegal, the
274 * driver should set and return the closest legal queue depth.
275 *
Pavel Machekd850bd32008-02-04 23:53:24 -0800276 * Status: OPTIONAL
Linus Torvalds1da177e2005-04-16 15:20:36 -0700277 */
Christoph Hellwigdb5ed4d2014-11-13 15:08:42 +0100278 int (* change_queue_depth)(struct scsi_device *, int);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700279
280 /*
Pavel Machekd850bd32008-02-04 23:53:24 -0800281 * This function determines the BIOS parameters for a given
Linus Torvalds1da177e2005-04-16 15:20:36 -0700282 * harddisk. These tend to be numbers that are made up by
283 * the host adapter. Parameters:
284 * size, device, list (heads, sectors, cylinders)
285 *
Pavel Machekd850bd32008-02-04 23:53:24 -0800286 * Status: OPTIONAL
287 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700288 int (* bios_param)(struct scsi_device *, struct block_device *,
289 sector_t, int []);
290
291 /*
Tejun Heo72ec24b2010-05-15 20:09:32 +0200292 * 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 /*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700300 * 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 */
Al Viro0ffddfb2013-03-30 23:58:05 -0400306 int (*show_info)(struct seq_file *, struct Scsi_Host *);
307 int (*write_info)(struct Scsi_Host *, char *, int);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700308
309 /*
James Bottomley6c5f8ce2007-03-16 17:44:41 -0500310 * 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 * EH_HANDLED: I fixed the error, please complete the command
314 * EH_RESET_TIMER: I need more time, reset the timer and
315 * begin counting again
316 * EH_NOT_HANDLED Begin normal error recovery
317 *
318 * Status: OPTIONAL
319 */
Jens Axboe242f9dc2008-09-14 05:55:09 -0700320 enum blk_eh_timer_return (*eh_timed_out)(struct scsi_cmnd *);
James Bottomley6c5f8ce2007-03-16 17:44:41 -0500321
Vikas Chaudhary29443692011-08-12 02:51:28 -0700322 /* This is an optional routine that allows transport to initiate
323 * LLD adapter or firmware reset using sysfs attribute.
324 *
325 * Return values: 0 on success, -ve value on failure.
326 *
327 * Status: OPTIONAL
328 */
329
330 int (*host_reset)(struct Scsi_Host *shost, int reset_type);
331#define SCSI_ADAPTER_RESET 1
332#define SCSI_FIRMWARE_RESET 2
333
334
James Bottomley6c5f8ce2007-03-16 17:44:41 -0500335 /*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700336 * Name of proc directory
337 */
Kristian Høgsbergb02b6bc2007-05-09 19:23:12 -0400338 const char *proc_name;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700339
340 /*
341 * Used to store the procfs directory if a driver implements the
Al Viro70ef4572013-03-31 13:27:56 -0400342 * show_info method.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700343 */
344 struct proc_dir_entry *proc_dir;
345
346 /*
347 * This determines if we will use a non-interrupt driven
Pavel Machekd850bd32008-02-04 23:53:24 -0800348 * or an interrupt driven scheme. It is set to the maximum number
Linus Torvalds1da177e2005-04-16 15:20:36 -0700349 * of simultaneous commands a given host adapter will accept.
350 */
351 int can_queue;
352
353 /*
354 * In many instances, especially where disconnect / reconnect are
355 * supported, our host also has an ID on the SCSI bus. If this is
356 * the case, then it must be reserved. Please set this_id to -1 if
357 * your setup is in single initiator mode, and the host lacks an
358 * ID.
359 */
360 int this_id;
361
362 /*
363 * This determines the degree to which the host adapter is capable
364 * of scatter-gather.
365 */
366 unsigned short sg_tablesize;
Martin K. Petersen13f05c82010-09-10 20:50:10 +0200367 unsigned short sg_prot_tablesize;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700368
369 /*
Pavel Machekd850bd32008-02-04 23:53:24 -0800370 * Set this if the host adapter has limitations beside segment count.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700371 */
Akinobu Mita8ed5a4d2014-06-02 22:56:48 +0900372 unsigned int max_sectors;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700373
374 /*
Pavel Machekd850bd32008-02-04 23:53:24 -0800375 * DMA scatter gather segment boundary limit. A segment crossing this
Linus Torvalds1da177e2005-04-16 15:20:36 -0700376 * boundary will be split in two.
377 */
378 unsigned long dma_boundary;
379
380 /*
381 * This specifies "machine infinity" for host templates which don't
382 * limit the transfer size. Note this limit represents an absolute
383 * maximum, and may be over the transfer limits allowed for
Pavel Machekd850bd32008-02-04 23:53:24 -0800384 * individual devices (e.g. 256 for SCSI-1).
Linus Torvalds1da177e2005-04-16 15:20:36 -0700385 */
386#define SCSI_DEFAULT_MAX_SECTORS 1024
387
388 /*
389 * True if this host adapter can make good use of linked commands.
390 * This will allow more than one command to be queued to a given
391 * unit on a given host. Set this to the maximum number of command
392 * blocks to be provided for each device. Set this to 1 for one
393 * command block per lun, 2 for two, etc. Do not set this to 0.
394 * You should make sure that the host adapter will do the right thing
395 * before you try setting this above 1.
396 */
397 short cmd_per_lun;
398
399 /*
400 * present contains counter indicating how many boards of this
401 * type were found when we did the scan.
402 */
403 unsigned char present;
404
Shaohua Liee1b6f72015-01-15 17:32:25 -0800405 /* If use block layer to manage tags, this is tag allocation policy */
406 int tag_alloc_policy;
407
Linus Torvalds1da177e2005-04-16 15:20:36 -0700408 /*
Christoph Hellwigc40ecc12014-11-13 14:25:11 +0100409 * Track QUEUE_FULL events and reduce queue depth on demand.
410 */
411 unsigned track_queue_depth:1;
412
413 /*
FUJITA Tomonori5dc2b892007-09-01 02:02:20 +0900414 * This specifies the mode that a LLD supports.
415 */
416 unsigned supported_mode:2;
417
418 /*
Pavel Machekd850bd32008-02-04 23:53:24 -0800419 * True if this host adapter uses unchecked DMA onto an ISA bus.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700420 */
421 unsigned unchecked_isa_dma:1;
422
423 /*
Pavel Machekd850bd32008-02-04 23:53:24 -0800424 * True if this host adapter can make good use of clustering.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700425 * I originally thought that if the tablesize was large that it
426 * was a waste of CPU cycles to prepare a cluster list, but
427 * it works out that the Buslogic is faster if you use a smaller
428 * number of segments (i.e. use clustering). I guess it is
429 * inefficient.
430 */
431 unsigned use_clustering:1;
432
433 /*
Pavel Machekd850bd32008-02-04 23:53:24 -0800434 * True for emulated SCSI host adapters (e.g. ATAPI).
Linus Torvalds1da177e2005-04-16 15:20:36 -0700435 */
436 unsigned emulated:1;
437
438 /*
439 * True if the low-level driver performs its own reset-settle delays.
440 */
441 unsigned skip_settle_delay:1;
442
Martin K. Petersen54b2b502013-10-23 06:25:40 -0400443 /* True if the controller does not support WRITE SAME */
444 unsigned no_write_same:1;
445
Linus Torvalds1da177e2005-04-16 15:20:36 -0700446 /*
Hannes Reineckee494f6a2013-11-11 13:44:54 +0100447 * True if asynchronous aborts are not supported
448 */
449 unsigned no_async_abort:1;
450
451 /*
Pavel Machekd850bd32008-02-04 23:53:24 -0800452 * Countdown for host blocking with no commands outstanding.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700453 */
454 unsigned int max_host_blocked;
455
456 /*
457 * Default value for the blocking. If the queue is empty,
458 * host_blocked counts down in the request_fn until it restarts
459 * host operations as zero is reached.
460 *
461 * FIXME: This should probably be a value in the template
462 */
463#define SCSI_DEFAULT_HOST_BLOCKED 7
464
465 /*
466 * Pointer to the sysfs class properties for this host, NULL terminated.
467 */
Tony Jonesee959b02008-02-22 00:13:36 +0100468 struct device_attribute **shost_attrs;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700469
470 /*
471 * Pointer to the SCSI device properties for this host, NULL terminated.
472 */
473 struct device_attribute **sdev_attrs;
474
475 /*
476 * List of hosts per template.
477 *
478 * This is only for use by scsi_module.c for legacy templates.
479 * For these access to it is synchronized implicitly by
480 * module_init/module_exit.
481 */
482 struct list_head legacy_hosts;
James Smart9e4f5e22009-03-26 13:33:19 -0400483
484 /*
485 * Vendor Identifier associated with the host
486 *
487 * Note: When specifying vendor_id, be sure to read the
488 * Vendor Type and ID formatting requirements specified in
489 * scsi_netlink.h
490 */
491 u64 vendor_id;
Christoph Hellwig89d9a562014-02-20 14:21:01 -0800492
493 /*
494 * Additional per-command data allocated for the driver.
495 */
496 unsigned int cmd_size;
497 struct scsi_host_cmd_pool *cmd_pool;
Christoph Hellwigd2852032014-01-17 12:06:53 +0100498
499 /* temporary flag to disable blk-mq I/O path */
500 bool disable_blk_mq;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700501};
502
503/*
Jeff Garzikf2812332010-11-16 02:10:29 -0500504 * Temporary #define for host lock push down. Can be removed when all
505 * drivers have been updated to take advantage of unlocked
506 * queuecommand.
507 *
508 */
509#define DEF_SCSI_QCMD(func_name) \
510 int func_name(struct Scsi_Host *shost, struct scsi_cmnd *cmd) \
511 { \
512 unsigned long irq_flags; \
513 int rc; \
514 spin_lock_irqsave(shost->host_lock, irq_flags); \
515 scsi_cmd_get_serial(shost, cmd); \
516 rc = func_name##_lck (cmd, cmd->scsi_done); \
517 spin_unlock_irqrestore(shost->host_lock, irq_flags); \
518 return rc; \
519 }
520
521
522/*
Mike Andersond3301872005-06-16 11:12:38 -0700523 * shost state: If you alter this, you also need to alter scsi_sysfs.c
524 * (for the ascii descriptions) and the state model enforcer:
525 * scsi_host_set_state()
Linus Torvalds1da177e2005-04-16 15:20:36 -0700526 */
Mike Andersond3301872005-06-16 11:12:38 -0700527enum scsi_host_state {
528 SHOST_CREATED = 1,
529 SHOST_RUNNING,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700530 SHOST_CANCEL,
Mike Andersond3301872005-06-16 11:12:38 -0700531 SHOST_DEL,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700532 SHOST_RECOVERY,
James Bottomley939647e2005-09-18 15:05:20 -0500533 SHOST_CANCEL_RECOVERY,
534 SHOST_DEL_RECOVERY,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700535};
536
537struct Scsi_Host {
538 /*
539 * __devices is protected by the host_lock, but you should
540 * usually use scsi_device_lookup / shost_for_each_device
541 * to access it and don't care about locking yourself.
Finn Thain542cb452014-10-03 11:42:17 +1000542 * In the rare case of being in irq context you can use
Linus Torvalds1da177e2005-04-16 15:20:36 -0700543 * their __ prefixed variants with the lock held. NEVER
544 * access this list directly from a driver.
545 */
546 struct list_head __devices;
547 struct list_head __targets;
548
549 struct scsi_host_cmd_pool *cmd_pool;
550 spinlock_t free_list_lock;
551 struct list_head free_list; /* backup store of cmd structs */
552 struct list_head starved_list;
553
554 spinlock_t default_lock;
555 spinlock_t *host_lock;
556
Arjan van de Ven0b950672006-01-11 13:16:10 +0100557 struct mutex scan_mutex;/* serialize scanning activity */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700558
559 struct list_head eh_cmd_q;
560 struct task_struct * ehandler; /* Error recovery thread. */
Christoph Hellwig7dfdc9a2005-10-31 18:49:52 +0100561 struct completion * eh_action; /* Wait for specific actions on the
562 host. */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700563 wait_queue_head_t host_wait;
564 struct scsi_host_template *hostt;
565 struct scsi_transport_template *transportt;
06f81ea2005-04-17 14:57:29 -0500566
567 /*
Pavel Machekd850bd32008-02-04 23:53:24 -0800568 * Area to keep a shared tag map (if needed, will be
569 * NULL if not).
James Bottomley86e33a22006-08-30 09:45:51 -0400570 */
Christoph Hellwigd2852032014-01-17 12:06:53 +0100571 union {
572 struct blk_queue_tag *bqt;
573 struct blk_mq_tag_set tag_set;
574 };
James Bottomley86e33a22006-08-30 09:45:51 -0400575
Christoph Hellwig74665012014-01-22 15:29:29 +0100576 atomic_t host_busy; /* commands actually active on low-level */
Christoph Hellwigcd9070c2014-01-23 12:07:41 +0100577 atomic_t host_blocked;
578
Christoph Hellwig74665012014-01-22 15:29:29 +0100579 unsigned int host_failed; /* commands that failed.
580 protected by host_lock */
Tejun Heoee7863b2006-05-15 20:57:20 +0900581 unsigned int host_eh_scheduled; /* EH scheduled without command */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700582
Matthew Wilcox6d49f632008-07-15 14:54:16 -0600583 unsigned int host_no; /* Used for IOCTL_GET_IDLUN, /proc/scsi et al. */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700584
Hannes Reineckeb4562022013-10-23 10:51:21 +0200585 /* next two fields are used to bound the time spent in error handling */
586 int eh_deadline;
587 unsigned long last_reset;
588
589
Linus Torvalds1da177e2005-04-16 15:20:36 -0700590 /*
591 * These three parameters can be used to allow for wide scsi,
592 * and for host adapters that support multiple busses
Sebastian Herbszt8e4a5da2014-09-20 13:37:55 +0200593 * The last two should be set to 1 more than the actual max id
Hannes Reinecke1abf6352014-06-25 15:27:38 +0200594 * or lun (e.g. 8 for SCSI parallel systems).
Linus Torvalds1da177e2005-04-16 15:20:36 -0700595 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700596 unsigned int max_channel;
Hannes Reinecke1abf6352014-06-25 15:27:38 +0200597 unsigned int max_id;
598 u64 max_lun;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700599
600 /*
601 * This is a unique identifier that must be assigned so that we
602 * have some way of identifying each detected host adapter properly
603 * and uniquely. For hosts that do not support more than one card
604 * in the system at one time, this does not need to be set. It is
605 * initialized to 0 in scsi_register.
606 */
607 unsigned int unique_id;
608
609 /*
610 * The maximum length of SCSI commands that this host can accept.
611 * Probably 12 for most host adapters, but could be 16 for others.
Boaz Harroshdb4742d2008-04-30 11:27:26 +0300612 * or 260 if the driver supports variable length cdbs.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700613 * For drivers that don't set this field, a value of 12 is
Boaz Harroshdb4742d2008-04-30 11:27:26 +0300614 * assumed.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700615 */
Boaz Harroshdb4742d2008-04-30 11:27:26 +0300616 unsigned short max_cmd_len;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700617
618 int this_id;
619 int can_queue;
620 short cmd_per_lun;
621 short unsigned int sg_tablesize;
Martin K. Petersen13f05c82010-09-10 20:50:10 +0200622 short unsigned int sg_prot_tablesize;
Akinobu Mita8ed5a4d2014-06-02 22:56:48 +0900623 unsigned int max_sectors;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700624 unsigned long dma_boundary;
Bart Van Asscheefec4b92014-10-30 14:45:36 +0100625 /*
626 * In scsi-mq mode, the number of hardware queues supported by the LLD.
627 *
628 * Note: it is assumed that each hardware queue has a queue depth of
629 * can_queue. In other words, the total queue depth per host
630 * is nr_hw_queues * can_queue.
631 */
632 unsigned nr_hw_queues;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700633 /*
634 * Used to assign serial numbers to the cmds.
635 * Protected by the host lock.
636 */
Matthew Wilcox12a44162007-09-18 19:54:43 -0600637 unsigned long cmd_serial_number;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700638
FUJITA Tomonori5dc2b892007-09-01 02:02:20 +0900639 unsigned active_mode:2;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700640 unsigned unchecked_isa_dma:1;
641 unsigned use_clustering:1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700642
643 /*
644 * Host has requested that no further requests come through for the
645 * time being.
646 */
647 unsigned host_self_blocked:1;
648
649 /*
650 * Host uses correct SCSI ordering not PC ordering. The bit is
651 * set for the minority of drivers whose authors actually read
Pavel Machekd850bd32008-02-04 23:53:24 -0800652 * the spec ;).
Linus Torvalds1da177e2005-04-16 15:20:36 -0700653 */
654 unsigned reverse_ordering:1;
655
Pavel Machekd850bd32008-02-04 23:53:24 -0800656 /* Task mgmt function in progress */
James Smartd7a1bb02006-03-08 14:50:12 -0500657 unsigned tmf_in_progress:1;
658
Matthew Wilcox3e082a92006-09-28 15:19:20 -0600659 /* Asynchronous scan in progress */
660 unsigned async_scan:1;
661
Lin Mingae0751f2011-12-05 09:20:24 +0800662 /* Don't resume host in EH */
663 unsigned eh_noresume:1;
664
Martin K. Petersen54b2b502013-10-23 06:25:40 -0400665 /* The controller does not support WRITE SAME */
666 unsigned no_write_same:1;
667
Christoph Hellwigd2852032014-01-17 12:06:53 +0100668 unsigned use_blk_mq:1;
Kashyap.Desai@avagotech.com64bdcbc2014-08-20 19:24:33 +0530669 unsigned use_cmd_list:1;
Christoph Hellwigd2852032014-01-17 12:06:53 +0100670
Vitaly Kuznetsova35bb442015-11-19 14:17:06 +0100671 /* Host responded with short (<36 bytes) INQUIRY result */
672 unsigned short_inquiry:1;
673
Linus Torvalds1da177e2005-04-16 15:20:36 -0700674 /*
675 * Optional work queue to be utilized by the transport
676 */
Kay Sieversaab0de22008-05-02 06:02:41 +0200677 char work_q_name[20];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700678 struct workqueue_struct *work_q;
679
680 /*
Hannes Reineckee494f6a2013-11-11 13:44:54 +0100681 * Task management function work queue
682 */
683 struct workqueue_struct *tmf_work_q;
684
Alan Stern50c4e962014-09-02 11:35:50 -0400685 /* The transport requires the LUN bits NOT to be stored in CDB[1] */
686 unsigned no_scsi2_lun_in_cdb:1;
687
Hannes Reineckee494f6a2013-11-11 13:44:54 +0100688 /*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700689 * Value host_blocked counts down from
690 */
691 unsigned int max_host_blocked;
692
Martin K. Petersen4469f982008-07-17 04:28:30 -0400693 /* Protection Information */
694 unsigned int prot_capabilities;
695 unsigned char prot_guard_type;
696
FUJITA Tomonorib58d9152006-11-16 19:24:10 +0900697 /*
698 * q used for scsi_tgt msgs, async events or any other requests that
699 * need to be processed in userspace
700 */
701 struct request_queue *uspace_req_q;
702
Linus Torvalds1da177e2005-04-16 15:20:36 -0700703 /* legacy crap */
704 unsigned long base;
705 unsigned long io_port;
706 unsigned char n_io_port;
707 unsigned char dma_channel;
708 unsigned int irq;
709
710
Mike Andersond3301872005-06-16 11:12:38 -0700711 enum scsi_host_state shost_state;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700712
713 /* ldm bits */
Tony Jonesee959b02008-02-22 00:13:36 +0100714 struct device shost_gendev, shost_dev;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700715
716 /*
717 * List of hosts per template.
718 *
719 * This is only for use by scsi_module.c for legacy templates.
720 * For these access to it is synchronized implicitly by
721 * module_init/module_exit.
722 */
723 struct list_head sht_legacy_list;
724
725 /*
726 * Points to the transport data (if any) which is allocated
727 * separately
728 */
729 void *shost_data;
730
731 /*
James Bottomleyd139b9b2009-11-05 13:33:12 -0600732 * Points to the physical bus device we'd use to do DMA
733 * Needed just in case we have virtual hosts.
734 */
735 struct device *dma_dev;
736
737 /*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700738 * We should ensure that this is aligned, both for better performance
739 * and also because some compilers (m68k) don't automatically force
740 * alignment to a long boundary.
741 */
742 unsigned long hostdata[0] /* Used for storage of host specific stuff */
743 __attribute__ ((aligned (sizeof(unsigned long))));
744};
745
746#define class_to_shost(d) \
Tony Jonesee959b02008-02-22 00:13:36 +0100747 container_of(d, struct Scsi_Host, shost_dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700748
James Bottomley9ccfc752005-10-02 11:45:08 -0500749#define shost_printk(prefix, shost, fmt, a...) \
750 dev_printk(prefix, &(shost)->shost_gendev, fmt, ##a)
751
Christoph Hellwigbcd92c92007-05-31 20:12:26 +0200752static inline void *shost_priv(struct Scsi_Host *shost)
753{
754 return (void *)shost->hostdata;
755}
James Bottomley9ccfc752005-10-02 11:45:08 -0500756
Linus Torvalds1da177e2005-04-16 15:20:36 -0700757int scsi_is_host_device(const struct device *);
758
759static inline struct Scsi_Host *dev_to_shost(struct device *dev)
760{
761 while (!scsi_is_host_device(dev)) {
762 if (!dev->parent)
763 return NULL;
764 dev = dev->parent;
765 }
766 return container_of(dev, struct Scsi_Host, shost_gendev);
767}
768
James Bottomley939647e2005-09-18 15:05:20 -0500769static inline int scsi_host_in_recovery(struct Scsi_Host *shost)
770{
771 return shost->shost_state == SHOST_RECOVERY ||
772 shost->shost_state == SHOST_CANCEL_RECOVERY ||
James Smartd7a1bb02006-03-08 14:50:12 -0500773 shost->shost_state == SHOST_DEL_RECOVERY ||
774 shost->tmf_in_progress;
James Bottomley939647e2005-09-18 15:05:20 -0500775}
776
Christoph Hellwigd2852032014-01-17 12:06:53 +0100777extern bool scsi_use_blk_mq;
778
779static inline bool shost_use_blk_mq(struct Scsi_Host *shost)
780{
781 return shost->use_blk_mq;
782}
783
Linus Torvalds1da177e2005-04-16 15:20:36 -0700784extern int scsi_queue_work(struct Scsi_Host *, struct work_struct *);
785extern void scsi_flush_work(struct Scsi_Host *);
786
787extern struct Scsi_Host *scsi_host_alloc(struct scsi_host_template *, int);
James Bottomleyd139b9b2009-11-05 13:33:12 -0600788extern int __must_check scsi_add_host_with_dma(struct Scsi_Host *,
789 struct device *,
790 struct device *);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700791extern void scsi_scan_host(struct Scsi_Host *);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700792extern void scsi_rescan_device(struct device *);
793extern void scsi_remove_host(struct Scsi_Host *);
794extern struct Scsi_Host *scsi_host_get(struct Scsi_Host *);
795extern void scsi_host_put(struct Scsi_Host *t);
796extern struct Scsi_Host *scsi_host_lookup(unsigned short);
Mike Andersond3301872005-06-16 11:12:38 -0700797extern const char *scsi_host_state_name(enum scsi_host_state);
Jeff Garzikf2812332010-11-16 02:10:29 -0500798extern void scsi_cmd_get_serial(struct Scsi_Host *, struct scsi_cmnd *);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700799
James Bottomleyd139b9b2009-11-05 13:33:12 -0600800static inline int __must_check scsi_add_host(struct Scsi_Host *host,
801 struct device *dev)
802{
803 return scsi_add_host_with_dma(host, dev, dev);
804}
805
Linus Torvalds1da177e2005-04-16 15:20:36 -0700806static inline struct device *scsi_get_device(struct Scsi_Host *shost)
807{
808 return shost->shost_gendev.parent;
809}
810
Mike Anderson82f29462005-06-16 11:14:33 -0700811/**
812 * scsi_host_scan_allowed - Is scanning of this host allowed
813 * @shost: Pointer to Scsi_Host.
814 **/
815static inline int scsi_host_scan_allowed(struct Scsi_Host *shost)
816{
Mike Christie76e4e122011-08-25 00:36:38 -0500817 return shost->shost_state == SHOST_RUNNING ||
818 shost->shost_state == SHOST_RECOVERY;
Mike Anderson82f29462005-06-16 11:14:33 -0700819}
820
Linus Torvalds1da177e2005-04-16 15:20:36 -0700821extern void scsi_unblock_requests(struct Scsi_Host *);
822extern void scsi_block_requests(struct Scsi_Host *);
823
824struct class_container;
FUJITA Tomonorib58d9152006-11-16 19:24:10 +0900825
826extern struct request_queue *__scsi_alloc_queue(struct Scsi_Host *shost,
827 void (*) (struct request_queue *));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700828/*
829 * These two functions are used to allocate and free a pseudo device
830 * which will connect to the host adapter itself rather than any
831 * physical device. You must deallocate when you are done with the
832 * thing. This physical pseudo-device isn't real and won't be available
833 * from any high-level drivers.
834 */
835extern void scsi_free_host_dev(struct scsi_device *);
836extern struct scsi_device *scsi_get_host_dev(struct Scsi_Host *);
837
Martin K. Petersen4469f982008-07-17 04:28:30 -0400838/*
839 * DIF defines the exchange of protection information between
840 * initiator and SBC block device.
841 *
842 * DIX defines the exchange of protection information between OS and
843 * initiator.
844 */
845enum scsi_host_prot_capabilities {
846 SHOST_DIF_TYPE1_PROTECTION = 1 << 0, /* T10 DIF Type 1 */
847 SHOST_DIF_TYPE2_PROTECTION = 1 << 1, /* T10 DIF Type 2 */
848 SHOST_DIF_TYPE3_PROTECTION = 1 << 2, /* T10 DIF Type 3 */
849
850 SHOST_DIX_TYPE0_PROTECTION = 1 << 3, /* DIX between OS and HBA only */
851 SHOST_DIX_TYPE1_PROTECTION = 1 << 4, /* DIX with DIF Type 1 */
852 SHOST_DIX_TYPE2_PROTECTION = 1 << 5, /* DIX with DIF Type 2 */
853 SHOST_DIX_TYPE3_PROTECTION = 1 << 6, /* DIX with DIF Type 3 */
854};
855
856/*
857 * SCSI hosts which support the Data Integrity Extensions must
858 * indicate their capabilities by setting the prot_capabilities using
859 * this call.
860 */
861static inline void scsi_host_set_prot(struct Scsi_Host *shost, unsigned int mask)
862{
863 shost->prot_capabilities = mask;
864}
865
866static inline unsigned int scsi_host_get_prot(struct Scsi_Host *shost)
867{
868 return shost->prot_capabilities;
869}
870
Martin K. Petersen13f05c82010-09-10 20:50:10 +0200871static inline int scsi_host_prot_dma(struct Scsi_Host *shost)
872{
873 return shost->prot_capabilities >= SHOST_DIX_TYPE0_PROTECTION;
874}
875
Martin K. Petersen4469f982008-07-17 04:28:30 -0400876static inline unsigned int scsi_host_dif_capable(struct Scsi_Host *shost, unsigned int target_type)
877{
Martin K. Petersenb2b465e2009-10-29 22:32:26 -0400878 static unsigned char cap[] = { 0,
879 SHOST_DIF_TYPE1_PROTECTION,
880 SHOST_DIF_TYPE2_PROTECTION,
881 SHOST_DIF_TYPE3_PROTECTION };
Martin K. Petersen4469f982008-07-17 04:28:30 -0400882
Martin K. Petersen4d248342012-09-26 22:39:44 -0400883 if (target_type >= ARRAY_SIZE(cap))
Martin K. Petersenfe542392012-09-21 12:44:12 -0400884 return 0;
885
Martin K. Petersenb2b465e2009-10-29 22:32:26 -0400886 return shost->prot_capabilities & cap[target_type] ? target_type : 0;
Martin K. Petersen4469f982008-07-17 04:28:30 -0400887}
888
889static inline unsigned int scsi_host_dix_capable(struct Scsi_Host *shost, unsigned int target_type)
890{
Martin K. Petersen35e1a5d2009-09-18 17:33:00 -0400891#if defined(CONFIG_BLK_DEV_INTEGRITY)
Martin K. Petersenb2b465e2009-10-29 22:32:26 -0400892 static unsigned char cap[] = { SHOST_DIX_TYPE0_PROTECTION,
893 SHOST_DIX_TYPE1_PROTECTION,
894 SHOST_DIX_TYPE2_PROTECTION,
895 SHOST_DIX_TYPE3_PROTECTION };
896
Martin K. Petersen4d248342012-09-26 22:39:44 -0400897 if (target_type >= ARRAY_SIZE(cap))
Martin K. Petersenfe542392012-09-21 12:44:12 -0400898 return 0;
899
Martin K. Petersenb2b465e2009-10-29 22:32:26 -0400900 return shost->prot_capabilities & cap[target_type];
Martin K. Petersen35e1a5d2009-09-18 17:33:00 -0400901#endif
Martin K. Petersen4469f982008-07-17 04:28:30 -0400902 return 0;
903}
904
905/*
906 * All DIX-capable initiators must support the T10-mandated CRC
907 * checksum. Controllers can optionally implement the IP checksum
908 * scheme which has much lower impact on system performance. Note
909 * that the main rationale for the checksum is to match integrity
910 * metadata with data. Detecting bit errors are a job for ECC memory
911 * and buses.
912 */
913
914enum scsi_host_guard_type {
915 SHOST_DIX_GUARD_CRC = 1 << 0,
916 SHOST_DIX_GUARD_IP = 1 << 1,
917};
918
919static inline void scsi_host_set_guard(struct Scsi_Host *shost, unsigned char type)
920{
921 shost->prot_guard_type = type;
922}
923
924static inline unsigned char scsi_host_get_guard(struct Scsi_Host *shost)
925{
926 return shost->prot_guard_type;
927}
928
Linus Torvalds1da177e2005-04-16 15:20:36 -0700929/* legacy interfaces */
930extern struct Scsi_Host *scsi_register(struct scsi_host_template *, int);
931extern void scsi_unregister(struct Scsi_Host *);
James Bottomley47ba39e2005-07-30 11:39:53 -0500932extern int scsi_host_set_state(struct Scsi_Host *, enum scsi_host_state);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700933
934#endif /* _SCSI_SCSI_HOST_H */