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