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_target; 20 struct Scsi_Host; 21 struct scsi_transport_template; 22 23 24 #define SG_ALL SG_CHUNK_SIZE 25 26 #define MODE_UNKNOWN 0x00 27 #define MODE_INITIATOR 0x01 28 #define MODE_TARGET 0x02 29 30 struct scsi_host_template { 31 /* 32 * Put fields referenced in IO submission path together in 33 * same cacheline 34 */ 35 36 /* 37 * Additional per-command data allocated for the driver. 38 */ 39 unsigned int cmd_size; 40 41 /* 42 * The queuecommand function is used to queue up a scsi 43 * command block to the LLDD. When the driver finished 44 * processing the command the done callback is invoked. 45 * 46 * If queuecommand returns 0, then the driver has accepted the 47 * command. It must also push it to the HBA if the scsi_cmnd 48 * flag SCMD_LAST is set, or if the driver does not implement 49 * commit_rqs. The done() function must be called on the command 50 * when the driver has finished with it. (you may call done on the 51 * command before queuecommand returns, but in this case you 52 * *must* return 0 from queuecommand). 53 * 54 * Queuecommand may also reject the command, in which case it may 55 * not touch the command and must not call done() for it. 56 * 57 * There are two possible rejection returns: 58 * 59 * SCSI_MLQUEUE_DEVICE_BUSY: Block this device temporarily, but 60 * allow commands to other devices serviced by this host. 61 * 62 * SCSI_MLQUEUE_HOST_BUSY: Block all devices served by this 63 * host temporarily. 64 * 65 * For compatibility, any other non-zero return is treated the 66 * same as SCSI_MLQUEUE_HOST_BUSY. 67 * 68 * NOTE: "temporarily" means either until the next command for# 69 * this device/host completes, or a period of time determined by 70 * I/O pressure in the system if there are no other outstanding 71 * commands. 72 * 73 * STATUS: REQUIRED 74 */ 75 int (* queuecommand)(struct Scsi_Host *, struct scsi_cmnd *); 76 77 /* 78 * The commit_rqs function is used to trigger a hardware 79 * doorbell after some requests have been queued with 80 * queuecommand, when an error is encountered before sending 81 * the request with SCMD_LAST set. 82 * 83 * STATUS: OPTIONAL 84 */ 85 void (*commit_rqs)(struct Scsi_Host *, u16); 86 87 struct module *module; 88 const char *name; 89 90 /* 91 * The info function will return whatever useful information the 92 * developer sees fit. If not provided, then the name field will 93 * be used instead. 94 * 95 * Status: OPTIONAL 96 */ 97 const char *(*info)(struct Scsi_Host *); 98 99 /* 100 * Ioctl interface 101 * 102 * Status: OPTIONAL 103 */ 104 int (*ioctl)(struct scsi_device *dev, unsigned int cmd, 105 void __user *arg); 106 107 108 #ifdef CONFIG_COMPAT 109 /* 110 * Compat handler. Handle 32bit ABI. 111 * When unknown ioctl is passed return -ENOIOCTLCMD. 112 * 113 * Status: OPTIONAL 114 */ 115 int (*compat_ioctl)(struct scsi_device *dev, unsigned int cmd, 116 void __user *arg); 117 #endif 118 119 int (*init_cmd_priv)(struct Scsi_Host *shost, struct scsi_cmnd *cmd); 120 int (*exit_cmd_priv)(struct Scsi_Host *shost, struct scsi_cmnd *cmd); 121 122 /* 123 * This is an error handling strategy routine. You don't need to 124 * define one of these if you don't want to - there is a default 125 * routine that is present that should work in most cases. For those 126 * driver authors that have the inclination and ability to write their 127 * own strategy routine, this is where it is specified. Note - the 128 * strategy routine is *ALWAYS* run in the context of the kernel eh 129 * thread. Thus you are guaranteed to *NOT* be in an interrupt 130 * handler when you execute this, and you are also guaranteed to 131 * *NOT* have any other commands being queued while you are in the 132 * strategy routine. When you return from this function, operations 133 * return to normal. 134 * 135 * See scsi_error.c scsi_unjam_host for additional comments about 136 * what this function should and should not be attempting to do. 137 * 138 * Status: REQUIRED (at least one of them) 139 */ 140 int (* eh_abort_handler)(struct scsi_cmnd *); 141 int (* eh_device_reset_handler)(struct scsi_cmnd *); 142 int (* eh_target_reset_handler)(struct scsi_cmnd *); 143 int (* eh_bus_reset_handler)(struct scsi_cmnd *); 144 int (* eh_host_reset_handler)(struct scsi_cmnd *); 145 146 /* 147 * Before the mid layer attempts to scan for a new device where none 148 * currently exists, it will call this entry in your driver. Should 149 * your driver need to allocate any structs or perform any other init 150 * items in order to send commands to a currently unused target/lun 151 * combo, then this is where you can perform those allocations. This 152 * is specifically so that drivers won't have to perform any kind of 153 * "is this a new device" checks in their queuecommand routine, 154 * thereby making the hot path a bit quicker. 155 * 156 * Return values: 0 on success, non-0 on failure 157 * 158 * Deallocation: If we didn't find any devices at this ID, you will 159 * get an immediate call to slave_destroy(). If we find something 160 * here then you will get a call to slave_configure(), then the 161 * device will be used for however long it is kept around, then when 162 * the device is removed from the system (or * possibly at reboot 163 * time), you will then get a call to slave_destroy(). This is 164 * assuming you implement slave_configure and slave_destroy. 165 * However, if you allocate memory and hang it off the device struct, 166 * then you must implement the slave_destroy() routine at a minimum 167 * in order to avoid leaking memory 168 * each time a device is tore down. 169 * 170 * Status: OPTIONAL 171 */ 172 int (* slave_alloc)(struct scsi_device *); 173 174 /* 175 * Once the device has responded to an INQUIRY and we know the 176 * device is online, we call into the low level driver with the 177 * struct scsi_device *. If the low level device driver implements 178 * this function, it *must* perform the task of setting the queue 179 * depth on the device. All other tasks are optional and depend 180 * on what the driver supports and various implementation details. 181 * 182 * Things currently recommended to be handled at this time include: 183 * 184 * 1. Setting the device queue depth. Proper setting of this is 185 * described in the comments for scsi_change_queue_depth. 186 * 2. Determining if the device supports the various synchronous 187 * negotiation protocols. The device struct will already have 188 * responded to INQUIRY and the results of the standard items 189 * will have been shoved into the various device flag bits, eg. 190 * device->sdtr will be true if the device supports SDTR messages. 191 * 3. Allocating command structs that the device will need. 192 * 4. Setting the default timeout on this device (if needed). 193 * 5. Anything else the low level driver might want to do on a device 194 * specific setup basis... 195 * 6. Return 0 on success, non-0 on error. The device will be marked 196 * as offline on error so that no access will occur. If you return 197 * non-0, your slave_destroy routine will never get called for this 198 * device, so don't leave any loose memory hanging around, clean 199 * up after yourself before returning non-0 200 * 201 * Status: OPTIONAL 202 */ 203 int (* slave_configure)(struct scsi_device *); 204 205 /* 206 * Immediately prior to deallocating the device and after all activity 207 * has ceased the mid layer calls this point so that the low level 208 * driver may completely detach itself from the scsi device and vice 209 * versa. The low level driver is responsible for freeing any memory 210 * it allocated in the slave_alloc or slave_configure calls. 211 * 212 * Status: OPTIONAL 213 */ 214 void (* slave_destroy)(struct scsi_device *); 215 216 /* 217 * Before the mid layer attempts to scan for a new device attached 218 * to a target where no target currently exists, it will call this 219 * entry in your driver. Should your driver need to allocate any 220 * structs or perform any other init items in order to send commands 221 * to a currently unused target, then this is where you can perform 222 * those allocations. 223 * 224 * Return values: 0 on success, non-0 on failure 225 * 226 * Status: OPTIONAL 227 */ 228 int (* target_alloc)(struct scsi_target *); 229 230 /* 231 * Immediately prior to deallocating the target structure, and 232 * after all activity to attached scsi devices has ceased, the 233 * midlayer calls this point so that the driver may deallocate 234 * and terminate any references to the target. 235 * 236 * Status: OPTIONAL 237 */ 238 void (* target_destroy)(struct scsi_target *); 239 240 /* 241 * If a host has the ability to discover targets on its own instead 242 * of scanning the entire bus, it can fill in this function and 243 * call scsi_scan_host(). This function will be called periodically 244 * until it returns 1 with the scsi_host and the elapsed time of 245 * the scan in jiffies. 246 * 247 * Status: OPTIONAL 248 */ 249 int (* scan_finished)(struct Scsi_Host *, unsigned long); 250 251 /* 252 * If the host wants to be called before the scan starts, but 253 * after the midlayer has set up ready for the scan, it can fill 254 * in this function. 255 * 256 * Status: OPTIONAL 257 */ 258 void (* scan_start)(struct Scsi_Host *); 259 260 /* 261 * Fill in this function to allow the queue depth of this host 262 * to be changeable (on a per device basis). Returns either 263 * the current queue depth setting (may be different from what 264 * was passed in) or an error. An error should only be 265 * returned if the requested depth is legal but the driver was 266 * unable to set it. If the requested depth is illegal, the 267 * driver should set and return the closest legal queue depth. 268 * 269 * Status: OPTIONAL 270 */ 271 int (* change_queue_depth)(struct scsi_device *, int); 272 273 /* 274 * This functions lets the driver expose the queue mapping 275 * to the block layer. 276 * 277 * Status: OPTIONAL 278 */ 279 void (* map_queues)(struct Scsi_Host *shost); 280 281 /* 282 * SCSI interface of blk_poll - poll for IO completions. 283 * Only applicable if SCSI LLD exposes multiple h/w queues. 284 * 285 * Return value: Number of completed entries found. 286 * 287 * Status: OPTIONAL 288 */ 289 int (* mq_poll)(struct Scsi_Host *shost, unsigned int queue_num); 290 291 /* 292 * Check if scatterlists need to be padded for DMA draining. 293 * 294 * Status: OPTIONAL 295 */ 296 bool (* dma_need_drain)(struct request *rq); 297 298 /* 299 * This function determines the BIOS parameters for a given 300 * harddisk. These tend to be numbers that are made up by 301 * the host adapter. Parameters: 302 * size, device, list (heads, sectors, cylinders) 303 * 304 * Status: OPTIONAL 305 */ 306 int (* bios_param)(struct scsi_device *, struct block_device *, 307 sector_t, int []); 308 309 /* 310 * This function is called when one or more partitions on the 311 * device reach beyond the end of the device. 312 * 313 * Status: OPTIONAL 314 */ 315 void (*unlock_native_capacity)(struct scsi_device *); 316 317 /* 318 * Can be used to export driver statistics and other infos to the 319 * world outside the kernel ie. userspace and it also provides an 320 * interface to feed the driver with information. 321 * 322 * Status: OBSOLETE 323 */ 324 int (*show_info)(struct seq_file *, struct Scsi_Host *); 325 int (*write_info)(struct Scsi_Host *, char *, int); 326 327 /* 328 * This is an optional routine that allows the transport to become 329 * involved when a scsi io timer fires. The return value tells the 330 * timer routine how to finish the io timeout handling. 331 * 332 * Status: OPTIONAL 333 */ 334 enum blk_eh_timer_return (*eh_timed_out)(struct scsi_cmnd *); 335 /* 336 * Optional routine that allows the transport to decide if a cmd 337 * is retryable. Return true if the transport is in a state the 338 * cmd should be retried on. 339 */ 340 bool (*eh_should_retry_cmd)(struct scsi_cmnd *scmd); 341 342 /* This is an optional routine that allows transport to initiate 343 * LLD adapter or firmware reset using sysfs attribute. 344 * 345 * Return values: 0 on success, -ve value on failure. 346 * 347 * Status: OPTIONAL 348 */ 349 350 int (*host_reset)(struct Scsi_Host *shost, int reset_type); 351 #define SCSI_ADAPTER_RESET 1 352 #define SCSI_FIRMWARE_RESET 2 353 354 355 /* 356 * Name of proc directory 357 */ 358 const char *proc_name; 359 360 /* 361 * Used to store the procfs directory if a driver implements the 362 * show_info method. 363 */ 364 struct proc_dir_entry *proc_dir; 365 366 /* 367 * This determines if we will use a non-interrupt driven 368 * or an interrupt driven scheme. It is set to the maximum number 369 * of simultaneous commands a single hw queue in HBA will accept. 370 */ 371 int can_queue; 372 373 /* 374 * In many instances, especially where disconnect / reconnect are 375 * supported, our host also has an ID on the SCSI bus. If this is 376 * the case, then it must be reserved. Please set this_id to -1 if 377 * your setup is in single initiator mode, and the host lacks an 378 * ID. 379 */ 380 int this_id; 381 382 /* 383 * This determines the degree to which the host adapter is capable 384 * of scatter-gather. 385 */ 386 unsigned short sg_tablesize; 387 unsigned short sg_prot_tablesize; 388 389 /* 390 * Set this if the host adapter has limitations beside segment count. 391 */ 392 unsigned int max_sectors; 393 394 /* 395 * Maximum size in bytes of a single segment. 396 */ 397 unsigned int max_segment_size; 398 399 /* 400 * DMA scatter gather segment boundary limit. A segment crossing this 401 * boundary will be split in two. 402 */ 403 unsigned long dma_boundary; 404 405 unsigned long virt_boundary_mask; 406 407 /* 408 * This specifies "machine infinity" for host templates which don't 409 * limit the transfer size. Note this limit represents an absolute 410 * maximum, and may be over the transfer limits allowed for 411 * individual devices (e.g. 256 for SCSI-1). 412 */ 413 #define SCSI_DEFAULT_MAX_SECTORS 1024 414 415 /* 416 * True if this host adapter can make good use of linked commands. 417 * This will allow more than one command to be queued to a given 418 * unit on a given host. Set this to the maximum number of command 419 * blocks to be provided for each device. Set this to 1 for one 420 * command block per lun, 2 for two, etc. Do not set this to 0. 421 * You should make sure that the host adapter will do the right thing 422 * before you try setting this above 1. 423 */ 424 short cmd_per_lun; 425 426 /* 427 * present contains counter indicating how many boards of this 428 * type were found when we did the scan. 429 */ 430 unsigned char present; 431 432 /* If use block layer to manage tags, this is tag allocation policy */ 433 int tag_alloc_policy; 434 435 /* 436 * Track QUEUE_FULL events and reduce queue depth on demand. 437 */ 438 unsigned track_queue_depth:1; 439 440 /* 441 * This specifies the mode that a LLD supports. 442 */ 443 unsigned supported_mode:2; 444 445 /* 446 * True for emulated SCSI host adapters (e.g. ATAPI). 447 */ 448 unsigned emulated:1; 449 450 /* 451 * True if the low-level driver performs its own reset-settle delays. 452 */ 453 unsigned skip_settle_delay:1; 454 455 /* True if the controller does not support WRITE SAME */ 456 unsigned no_write_same:1; 457 458 /* True if the host uses host-wide tagspace */ 459 unsigned host_tagset:1; 460 461 /* 462 * Countdown for host blocking with no commands outstanding. 463 */ 464 unsigned int max_host_blocked; 465 466 /* 467 * Default value for the blocking. If the queue is empty, 468 * host_blocked counts down in the request_fn until it restarts 469 * host operations as zero is reached. 470 * 471 * FIXME: This should probably be a value in the template 472 */ 473 #define SCSI_DEFAULT_HOST_BLOCKED 7 474 475 /* 476 * Pointer to the SCSI host sysfs attribute groups, NULL terminated. 477 */ 478 const struct attribute_group **shost_groups; 479 480 /* 481 * Pointer to the SCSI device attribute groups for this host, 482 * NULL terminated. 483 */ 484 const struct attribute_group **sdev_groups; 485 486 /* 487 * Vendor Identifier associated with the host 488 * 489 * Note: When specifying vendor_id, be sure to read the 490 * Vendor Type and ID formatting requirements specified in 491 * scsi_netlink.h 492 */ 493 u64 vendor_id; 494 495 /* Delay for runtime autosuspend */ 496 int rpm_autosuspend_delay; 497 }; 498 499 /* 500 * Temporary #define for host lock push down. Can be removed when all 501 * drivers have been updated to take advantage of unlocked 502 * queuecommand. 503 * 504 */ 505 #define DEF_SCSI_QCMD(func_name) \ 506 int func_name(struct Scsi_Host *shost, struct scsi_cmnd *cmd) \ 507 { \ 508 unsigned long irq_flags; \ 509 int rc; \ 510 spin_lock_irqsave(shost->host_lock, irq_flags); \ 511 rc = func_name##_lck(cmd); \ 512 spin_unlock_irqrestore(shost->host_lock, irq_flags); \ 513 return rc; \ 514 } 515 516 517 /* 518 * shost state: If you alter this, you also need to alter scsi_sysfs.c 519 * (for the ascii descriptions) and the state model enforcer: 520 * scsi_host_set_state() 521 */ 522 enum scsi_host_state { 523 SHOST_CREATED = 1, 524 SHOST_RUNNING, 525 SHOST_CANCEL, 526 SHOST_DEL, 527 SHOST_RECOVERY, 528 SHOST_CANCEL_RECOVERY, 529 SHOST_DEL_RECOVERY, 530 }; 531 532 struct Scsi_Host { 533 /* 534 * __devices is protected by the host_lock, but you should 535 * usually use scsi_device_lookup / shost_for_each_device 536 * to access it and don't care about locking yourself. 537 * In the rare case of being in irq context you can use 538 * their __ prefixed variants with the lock held. NEVER 539 * access this list directly from a driver. 540 */ 541 struct list_head __devices; 542 struct list_head __targets; 543 544 struct list_head starved_list; 545 546 spinlock_t default_lock; 547 spinlock_t *host_lock; 548 549 struct mutex scan_mutex;/* serialize scanning activity */ 550 551 struct list_head eh_abort_list; 552 struct list_head eh_cmd_q; 553 struct task_struct * ehandler; /* Error recovery thread. */ 554 struct completion * eh_action; /* Wait for specific actions on the 555 host. */ 556 wait_queue_head_t host_wait; 557 struct scsi_host_template *hostt; 558 struct scsi_transport_template *transportt; 559 560 struct kref tagset_refcnt; 561 struct completion tagset_freed; 562 /* Area to keep a shared tag map */ 563 struct blk_mq_tag_set tag_set; 564 565 atomic_t host_blocked; 566 567 unsigned int host_failed; /* commands that failed. 568 protected by host_lock */ 569 unsigned int host_eh_scheduled; /* EH scheduled without command */ 570 571 unsigned int host_no; /* Used for IOCTL_GET_IDLUN, /proc/scsi et al. */ 572 573 /* next two fields are used to bound the time spent in error handling */ 574 int eh_deadline; 575 unsigned long last_reset; 576 577 578 /* 579 * These three parameters can be used to allow for wide scsi, 580 * and for host adapters that support multiple busses 581 * The last two should be set to 1 more than the actual max id 582 * or lun (e.g. 8 for SCSI parallel systems). 583 */ 584 unsigned int max_channel; 585 unsigned int max_id; 586 u64 max_lun; 587 588 /* 589 * This is a unique identifier that must be assigned so that we 590 * have some way of identifying each detected host adapter properly 591 * and uniquely. For hosts that do not support more than one card 592 * in the system at one time, this does not need to be set. It is 593 * initialized to 0 in scsi_register. 594 */ 595 unsigned int unique_id; 596 597 /* 598 * The maximum length of SCSI commands that this host can accept. 599 * Probably 12 for most host adapters, but could be 16 for others. 600 * or 260 if the driver supports variable length cdbs. 601 * For drivers that don't set this field, a value of 12 is 602 * assumed. 603 */ 604 unsigned short max_cmd_len; 605 606 int this_id; 607 int can_queue; 608 short cmd_per_lun; 609 short unsigned int sg_tablesize; 610 short unsigned int sg_prot_tablesize; 611 unsigned int max_sectors; 612 unsigned int opt_sectors; 613 unsigned int max_segment_size; 614 unsigned long dma_boundary; 615 unsigned long virt_boundary_mask; 616 /* 617 * In scsi-mq mode, the number of hardware queues supported by the LLD. 618 * 619 * Note: it is assumed that each hardware queue has a queue depth of 620 * can_queue. In other words, the total queue depth per host 621 * is nr_hw_queues * can_queue. However, for when host_tagset is set, 622 * the total queue depth is can_queue. 623 */ 624 unsigned nr_hw_queues; 625 unsigned nr_maps; 626 unsigned active_mode:2; 627 628 /* 629 * Host has requested that no further requests come through for the 630 * time being. 631 */ 632 unsigned host_self_blocked:1; 633 634 /* 635 * Host uses correct SCSI ordering not PC ordering. The bit is 636 * set for the minority of drivers whose authors actually read 637 * the spec ;). 638 */ 639 unsigned reverse_ordering:1; 640 641 /* Task mgmt function in progress */ 642 unsigned tmf_in_progress:1; 643 644 /* Asynchronous scan in progress */ 645 unsigned async_scan:1; 646 647 /* Don't resume host in EH */ 648 unsigned eh_noresume:1; 649 650 /* The controller does not support WRITE SAME */ 651 unsigned no_write_same:1; 652 653 /* True if the host uses host-wide tagspace */ 654 unsigned host_tagset:1; 655 656 /* Host responded with short (<36 bytes) INQUIRY result */ 657 unsigned short_inquiry:1; 658 659 /* The transport requires the LUN bits NOT to be stored in CDB[1] */ 660 unsigned no_scsi2_lun_in_cdb:1; 661 662 /* 663 * Optional work queue to be utilized by the transport 664 */ 665 char work_q_name[20]; 666 struct workqueue_struct *work_q; 667 668 /* 669 * Task management function work queue 670 */ 671 struct workqueue_struct *tmf_work_q; 672 673 /* 674 * Value host_blocked counts down from 675 */ 676 unsigned int max_host_blocked; 677 678 /* Protection Information */ 679 unsigned int prot_capabilities; 680 unsigned char prot_guard_type; 681 682 /* legacy crap */ 683 unsigned long base; 684 unsigned long io_port; 685 unsigned char n_io_port; 686 unsigned char dma_channel; 687 unsigned int irq; 688 689 690 enum scsi_host_state shost_state; 691 692 /* ldm bits */ 693 struct device shost_gendev, shost_dev; 694 695 /* 696 * Points to the transport data (if any) which is allocated 697 * separately 698 */ 699 void *shost_data; 700 701 /* 702 * Points to the physical bus device we'd use to do DMA 703 * Needed just in case we have virtual hosts. 704 */ 705 struct device *dma_dev; 706 707 /* 708 * We should ensure that this is aligned, both for better performance 709 * and also because some compilers (m68k) don't automatically force 710 * alignment to a long boundary. 711 */ 712 unsigned long hostdata[] /* Used for storage of host specific stuff */ 713 __attribute__ ((aligned (sizeof(unsigned long)))); 714 }; 715 716 #define class_to_shost(d) \ 717 container_of(d, struct Scsi_Host, shost_dev) 718 719 #define shost_printk(prefix, shost, fmt, a...) \ 720 dev_printk(prefix, &(shost)->shost_gendev, fmt, ##a) 721 722 static inline void *shost_priv(struct Scsi_Host *shost) 723 { 724 return (void *)shost->hostdata; 725 } 726 727 int scsi_is_host_device(const struct device *); 728 729 static inline struct Scsi_Host *dev_to_shost(struct device *dev) 730 { 731 while (!scsi_is_host_device(dev)) { 732 if (!dev->parent) 733 return NULL; 734 dev = dev->parent; 735 } 736 return container_of(dev, struct Scsi_Host, shost_gendev); 737 } 738 739 static inline int scsi_host_in_recovery(struct Scsi_Host *shost) 740 { 741 return shost->shost_state == SHOST_RECOVERY || 742 shost->shost_state == SHOST_CANCEL_RECOVERY || 743 shost->shost_state == SHOST_DEL_RECOVERY || 744 shost->tmf_in_progress; 745 } 746 747 extern int scsi_queue_work(struct Scsi_Host *, struct work_struct *); 748 extern void scsi_flush_work(struct Scsi_Host *); 749 750 extern struct Scsi_Host *scsi_host_alloc(struct scsi_host_template *, int); 751 extern int __must_check scsi_add_host_with_dma(struct Scsi_Host *, 752 struct device *, 753 struct device *); 754 extern void scsi_scan_host(struct Scsi_Host *); 755 extern void scsi_rescan_device(struct device *); 756 extern void scsi_remove_host(struct Scsi_Host *); 757 extern struct Scsi_Host *scsi_host_get(struct Scsi_Host *); 758 extern int scsi_host_busy(struct Scsi_Host *shost); 759 extern void scsi_host_put(struct Scsi_Host *t); 760 extern struct Scsi_Host *scsi_host_lookup(unsigned short); 761 extern const char *scsi_host_state_name(enum scsi_host_state); 762 extern void scsi_host_complete_all_commands(struct Scsi_Host *shost, 763 enum scsi_host_status status); 764 765 static inline int __must_check scsi_add_host(struct Scsi_Host *host, 766 struct device *dev) 767 { 768 return scsi_add_host_with_dma(host, dev, dev); 769 } 770 771 static inline struct device *scsi_get_device(struct Scsi_Host *shost) 772 { 773 return shost->shost_gendev.parent; 774 } 775 776 /** 777 * scsi_host_scan_allowed - Is scanning of this host allowed 778 * @shost: Pointer to Scsi_Host. 779 **/ 780 static inline int scsi_host_scan_allowed(struct Scsi_Host *shost) 781 { 782 return shost->shost_state == SHOST_RUNNING || 783 shost->shost_state == SHOST_RECOVERY; 784 } 785 786 extern void scsi_unblock_requests(struct Scsi_Host *); 787 extern void scsi_block_requests(struct Scsi_Host *); 788 extern int scsi_host_block(struct Scsi_Host *shost); 789 extern int scsi_host_unblock(struct Scsi_Host *shost, int new_state); 790 791 void scsi_host_busy_iter(struct Scsi_Host *, 792 bool (*fn)(struct scsi_cmnd *, void *), void *priv); 793 794 struct class_container; 795 796 /* 797 * DIF defines the exchange of protection information between 798 * initiator and SBC block device. 799 * 800 * DIX defines the exchange of protection information between OS and 801 * initiator. 802 */ 803 enum scsi_host_prot_capabilities { 804 SHOST_DIF_TYPE1_PROTECTION = 1 << 0, /* T10 DIF Type 1 */ 805 SHOST_DIF_TYPE2_PROTECTION = 1 << 1, /* T10 DIF Type 2 */ 806 SHOST_DIF_TYPE3_PROTECTION = 1 << 2, /* T10 DIF Type 3 */ 807 808 SHOST_DIX_TYPE0_PROTECTION = 1 << 3, /* DIX between OS and HBA only */ 809 SHOST_DIX_TYPE1_PROTECTION = 1 << 4, /* DIX with DIF Type 1 */ 810 SHOST_DIX_TYPE2_PROTECTION = 1 << 5, /* DIX with DIF Type 2 */ 811 SHOST_DIX_TYPE3_PROTECTION = 1 << 6, /* DIX with DIF Type 3 */ 812 }; 813 814 /* 815 * SCSI hosts which support the Data Integrity Extensions must 816 * indicate their capabilities by setting the prot_capabilities using 817 * this call. 818 */ 819 static inline void scsi_host_set_prot(struct Scsi_Host *shost, unsigned int mask) 820 { 821 shost->prot_capabilities = mask; 822 } 823 824 static inline unsigned int scsi_host_get_prot(struct Scsi_Host *shost) 825 { 826 return shost->prot_capabilities; 827 } 828 829 static inline int scsi_host_prot_dma(struct Scsi_Host *shost) 830 { 831 return shost->prot_capabilities >= SHOST_DIX_TYPE0_PROTECTION; 832 } 833 834 static inline unsigned int scsi_host_dif_capable(struct Scsi_Host *shost, unsigned int target_type) 835 { 836 static unsigned char cap[] = { 0, 837 SHOST_DIF_TYPE1_PROTECTION, 838 SHOST_DIF_TYPE2_PROTECTION, 839 SHOST_DIF_TYPE3_PROTECTION }; 840 841 if (target_type >= ARRAY_SIZE(cap)) 842 return 0; 843 844 return shost->prot_capabilities & cap[target_type] ? target_type : 0; 845 } 846 847 static inline unsigned int scsi_host_dix_capable(struct Scsi_Host *shost, unsigned int target_type) 848 { 849 #if defined(CONFIG_BLK_DEV_INTEGRITY) 850 static unsigned char cap[] = { SHOST_DIX_TYPE0_PROTECTION, 851 SHOST_DIX_TYPE1_PROTECTION, 852 SHOST_DIX_TYPE2_PROTECTION, 853 SHOST_DIX_TYPE3_PROTECTION }; 854 855 if (target_type >= ARRAY_SIZE(cap)) 856 return 0; 857 858 return shost->prot_capabilities & cap[target_type]; 859 #endif 860 return 0; 861 } 862 863 /* 864 * All DIX-capable initiators must support the T10-mandated CRC 865 * checksum. Controllers can optionally implement the IP checksum 866 * scheme which has much lower impact on system performance. Note 867 * that the main rationale for the checksum is to match integrity 868 * metadata with data. Detecting bit errors are a job for ECC memory 869 * and buses. 870 */ 871 872 enum scsi_host_guard_type { 873 SHOST_DIX_GUARD_CRC = 1 << 0, 874 SHOST_DIX_GUARD_IP = 1 << 1, 875 }; 876 877 static inline void scsi_host_set_guard(struct Scsi_Host *shost, unsigned char type) 878 { 879 shost->prot_guard_type = type; 880 } 881 882 static inline unsigned char scsi_host_get_guard(struct Scsi_Host *shost) 883 { 884 return shost->prot_guard_type; 885 } 886 887 extern int scsi_host_set_state(struct Scsi_Host *, enum scsi_host_state); 888 889 #endif /* _SCSI_SCSI_HOST_H */ 890