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 For new-style drivers 52 * just perform all work in your module initialization function. 53 * 54 * Status: OBSOLETE 55 */ 56 int (* detect)(struct scsi_host_template *); 57 58 /* 59 * Used as unload callback for hosts with old-style drivers. 60 * 61 * Status: OBSOLETE 62 */ 63 int (* release)(struct Scsi_Host *); 64 65 /* 66 * The info function will return whatever useful information the 67 * developer sees fit.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