1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef _SCSI_SCSI_HOST_H 3 #define _SCSI_SCSI_HOST_H 4 5 #include <linux/cleanup.h> 6 #include <linux/device.h> 7 #include <linux/list.h> 8 #include <linux/types.h> 9 #include <linux/workqueue.h> 10 #include <linux/mutex.h> 11 #include <linux/seq_file.h> 12 #include <linux/blk-mq.h> 13 #include <scsi/scsi.h> 14 15 struct block_device; 16 struct completion; 17 struct module; 18 struct scsi_cmnd; 19 struct scsi_device; 20 struct scsi_target; 21 struct Scsi_Host; 22 struct scsi_transport_template; 23 24 25 #define SG_ALL SG_CHUNK_SIZE 26 27 #define MODE_UNKNOWN 0x00 28 #define MODE_INITIATOR 0x01 29 #define MODE_TARGET 0x02 30 31 /** 32 * enum scsi_timeout_action - How to handle a command that timed out. 33 * @SCSI_EH_DONE: The command has already been completed. 34 * @SCSI_EH_RESET_TIMER: Reset the timer and continue waiting for completion. 35 * @SCSI_EH_NOT_HANDLED: The command has not yet finished. Abort the command. 36 */ 37 enum scsi_timeout_action { 38 SCSI_EH_DONE, 39 SCSI_EH_RESET_TIMER, 40 SCSI_EH_NOT_HANDLED, 41 }; 42 43 struct scsi_host_template { 44 /* 45 * Put fields referenced in IO submission path together in 46 * same cacheline 47 */ 48 49 /* 50 * Additional per-command data allocated for the driver. 51 */ 52 unsigned int cmd_size; 53 54 /* 55 * The queuecommand function is used to queue up a scsi 56 * command block to the LLDD. When the driver finished 57 * processing the command the done callback is invoked. 58 * 59 * If queuecommand returns 0, then the driver has accepted the 60 * command. It must also push it to the HBA if the scsi_cmnd 61 * flag SCMD_LAST is set, or if the driver does not implement 62 * commit_rqs. The done() function must be called on the command 63 * when the driver has finished with it. (you may call done on the 64 * command before queuecommand returns, but in this case you 65 * *must* return 0 from queuecommand). 66 * 67 * Queuecommand may also reject the command, in which case it may 68 * not touch the command and must not call done() for it. 69 * 70 * There are two possible rejection returns: 71 * 72 * SCSI_MLQUEUE_DEVICE_BUSY: Block this device temporarily, but 73 * allow commands to other devices serviced by this host. 74 * 75 * SCSI_MLQUEUE_HOST_BUSY: Block all devices served by this 76 * host temporarily. 77 * 78 * For compatibility, any other non-zero return is treated the 79 * same as SCSI_MLQUEUE_HOST_BUSY. 80 * 81 * NOTE: "temporarily" means either until the next command for# 82 * this device/host completes, or a period of time determined by 83 * I/O pressure in the system if there are no other outstanding 84 * commands. 85 * 86 * STATUS: REQUIRED 87 */ 88 enum scsi_qc_status (*queuecommand)(struct Scsi_Host *, 89 struct scsi_cmnd *); 90 91 /* 92 * Queue a reserved command (BLK_MQ_REQ_RESERVED). The .queuecommand() 93 * documentation also applies to the .queue_reserved_command() callback. 94 */ 95 enum scsi_qc_status (*queue_reserved_command)(struct Scsi_Host *, 96 struct scsi_cmnd *); 97 98 /* 99 * The commit_rqs function is used to trigger a hardware 100 * doorbell after some requests have been queued with 101 * queuecommand, when an error is encountered before sending 102 * the request with SCMD_LAST set. 103 * 104 * STATUS: OPTIONAL 105 */ 106 void (*commit_rqs)(struct Scsi_Host *, u16); 107 108 struct module *module; 109 const char *name; 110 111 /* 112 * The info function will return whatever useful information the 113 * developer sees fit. If not provided, then the name field will 114 * be used instead. 115 * 116 * Status: OPTIONAL 117 */ 118 const char *(*info)(struct Scsi_Host *); 119 120 /* 121 * Ioctl interface 122 * 123 * Status: OPTIONAL 124 */ 125 int (*ioctl)(struct scsi_device *dev, unsigned int cmd, 126 void __user *arg); 127 128 129 #ifdef CONFIG_COMPAT 130 /* 131 * Compat handler. Handle 32bit ABI. 132 * When unknown ioctl is passed return -ENOIOCTLCMD. 133 * 134 * Status: OPTIONAL 135 */ 136 int (*compat_ioctl)(struct scsi_device *dev, unsigned int cmd, 137 void __user *arg); 138 #endif 139 140 int (*init_cmd_priv)(struct Scsi_Host *shost, struct scsi_cmnd *cmd); 141 int (*exit_cmd_priv)(struct Scsi_Host *shost, struct scsi_cmnd *cmd); 142 143 /* 144 * This is an error handling strategy routine. You don't need to 145 * define one of these if you don't want to - there is a default 146 * routine that is present that should work in most cases. For those 147 * driver authors that have the inclination and ability to write their 148 * own strategy routine, this is where it is specified. Note - the 149 * strategy routine is *ALWAYS* run in the context of the kernel eh 150 * thread. Thus you are guaranteed to *NOT* be in an interrupt 151 * handler when you execute this, and you are also guaranteed to 152 * *NOT* have any other commands being queued while you are in the 153 * strategy routine. When you return from this function, operations 154 * return to normal. 155 * 156 * See scsi_error.c scsi_unjam_host for additional comments about 157 * what this function should and should not be attempting to do. 158 * 159 * Status: REQUIRED (at least one of them) 160 */ 161 int (* eh_abort_handler)(struct scsi_cmnd *); 162 int (* eh_device_reset_handler)(struct scsi_cmnd *); 163 int (* eh_target_reset_handler)(struct scsi_cmnd *); 164 int (* eh_bus_reset_handler)(struct scsi_cmnd *); 165 int (* eh_host_reset_handler)(struct scsi_cmnd *); 166 167 /* 168 * Before the mid layer attempts to scan for a new device where none 169 * currently exists, it will call this entry in your driver. Should 170 * your driver need to allocate any structs or perform any other init 171 * items in order to send commands to a currently unused target/lun 172 * combo, then this is where you can perform those allocations. This 173 * is specifically so that drivers won't have to perform any kind of 174 * "is this a new device" checks in their queuecommand routine, 175 * thereby making the hot path a bit quicker. 176 * 177 * Return values: 0 on success, non-0 on failure 178 * 179 * Deallocation: If we didn't find any devices at this ID, you will 180 * get an immediate call to sdev_destroy(). If we find something 181 * here then you will get a call to sdev_configure(), then the 182 * device will be used for however long it is kept around, then when 183 * the device is removed from the system (or * possibly at reboot 184 * time), you will then get a call to sdev_destroy(). This is 185 * assuming you implement sdev_configure and sdev_destroy. 186 * However, if you allocate memory and hang it off the device struct, 187 * then you must implement the sdev_destroy() routine at a minimum 188 * in order to avoid leaking memory 189 * each time a device is tore down. 190 * 191 * Status: OPTIONAL 192 */ 193 int (* sdev_init)(struct scsi_device *); 194 195 /* 196 * Once the device has responded to an INQUIRY and we know the 197 * device is online, we call into the low level driver with the 198 * struct scsi_device *. If the low level device driver implements 199 * this function, it *must* perform the task of setting the queue 200 * depth on the device. All other tasks are optional and depend 201 * on what the driver supports and various implementation details. 202 * 203 * Things currently recommended to be handled at this time include: 204 * 205 * 1. Setting the device queue depth. Proper setting of this is 206 * described in the comments for scsi_change_queue_depth. 207 * 2. Determining if the device supports the various synchronous 208 * negotiation protocols. The device struct will already have 209 * responded to INQUIRY and the results of the standard items 210 * will have been shoved into the various device flag bits, eg. 211 * device->sdtr will be true if the device supports SDTR messages. 212 * 3. Allocating command structs that the device will need. 213 * 4. Setting the default timeout on this device (if needed). 214 * 5. Anything else the low level driver might want to do on a device 215 * specific setup basis... 216 * 6. Return 0 on success, non-0 on error. The device will be marked 217 * as offline on error so that no access will occur. If you return 218 * non-0, your sdev_destroy routine will never get called for this 219 * device, so don't leave any loose memory hanging around, clean 220 * up after yourself before returning non-0 221 * 222 * Status: OPTIONAL 223 */ 224 int (* sdev_configure)(struct scsi_device *, struct queue_limits *lim); 225 226 /* 227 * Immediately prior to deallocating the device and after all activity 228 * has ceased the mid layer calls this point so that the low level 229 * driver may completely detach itself from the scsi device and vice 230 * versa. The low level driver is responsible for freeing any memory 231 * it allocated in the sdev_init or sdev_configure calls. 232 * 233 * Status: OPTIONAL 234 */ 235 void (* sdev_destroy)(struct scsi_device *); 236 237 /* 238 * Before the mid layer attempts to scan for a new device attached 239 * to a target where no target currently exists, it will call this 240 * entry in your driver. Should your driver need to allocate any 241 * structs or perform any other init items in order to send commands 242 * to a currently unused target, then this is where you can perform 243 * those allocations. 244 * 245 * Return values: 0 on success, non-0 on failure 246 * 247 * Status: OPTIONAL 248 */ 249 int (* target_alloc)(struct scsi_target *); 250 251 /* 252 * Immediately prior to deallocating the target structure, and 253 * after all activity to attached scsi devices has ceased, the 254 * midlayer calls this point so that the driver may deallocate 255 * and terminate any references to the target. 256 * 257 * Note: This callback is called with the host lock held and hence 258 * must not sleep. 259 * 260 * Status: OPTIONAL 261 */ 262 void (* target_destroy)(struct scsi_target *); 263 264 /* 265 * If a host has the ability to discover targets on its own instead 266 * of scanning the entire bus, it can fill in this function and 267 * call scsi_scan_host(). This function will be called periodically 268 * until it returns 1 with the scsi_host and the elapsed time of 269 * the scan in jiffies. 270 * 271 * Status: OPTIONAL 272 */ 273 int (* scan_finished)(struct Scsi_Host *, unsigned long); 274 275 /* 276 * If the host wants to be called before the scan starts, but 277 * after the midlayer has set up ready for the scan, it can fill 278 * in this function. 279 * 280 * Status: OPTIONAL 281 */ 282 void (* scan_start)(struct Scsi_Host *); 283 284 /* 285 * Fill in this function to allow the queue depth of this host 286 * to be changeable (on a per device basis). Returns either 287 * the current queue depth setting (may be different from what 288 * was passed in) or an error. An error should only be 289 * returned if the requested depth is legal but the driver was 290 * unable to set it. If the requested depth is illegal, the 291 * driver should set and return the closest legal queue depth. 292 * 293 * Status: OPTIONAL 294 */ 295 int (* change_queue_depth)(struct scsi_device *, int); 296 297 /* 298 * This functions lets the driver expose the queue mapping 299 * to the block layer. 300 * 301 * Status: OPTIONAL 302 */ 303 void (* map_queues)(struct Scsi_Host *shost); 304 305 /* 306 * SCSI interface of blk_poll - poll for IO completions. 307 * Only applicable if SCSI LLD exposes multiple h/w queues. 308 * 309 * Return value: Number of completed entries found. 310 * 311 * Status: OPTIONAL 312 */ 313 int (* mq_poll)(struct Scsi_Host *shost, unsigned int queue_num); 314 315 /* 316 * Check if scatterlists need to be padded for DMA draining. 317 * 318 * Status: OPTIONAL 319 */ 320 bool (* dma_need_drain)(struct request *rq); 321 322 /* 323 * This function determines the BIOS parameters for a given 324 * harddisk. These tend to be numbers that are made up by 325 * the host adapter. Parameters: 326 * size, device, list (heads, sectors, cylinders) 327 * 328 * Status: OPTIONAL 329 */ 330 int (* bios_param)(struct scsi_device *, struct gendisk *, 331 sector_t, int []); 332 333 /* 334 * This function is called when one or more partitions on the 335 * device reach beyond the end of the device. 336 * 337 * Status: OPTIONAL 338 */ 339 void (*unlock_native_capacity)(struct scsi_device *); 340 341 /* 342 * Can be used to export driver statistics and other infos to the 343 * world outside the kernel ie. userspace and it also provides an 344 * interface to feed the driver with information. 345 * 346 * Status: OBSOLETE 347 */ 348 int (*show_info)(struct seq_file *, struct Scsi_Host *); 349 int (*write_info)(struct Scsi_Host *, char *, int); 350 351 /* 352 * This is an optional routine that allows the transport to become 353 * involved when a scsi io timer fires. The return value tells the 354 * timer routine how to finish the io timeout handling. 355 * 356 * Status: OPTIONAL 357 */ 358 enum scsi_timeout_action (*eh_timed_out)(struct scsi_cmnd *); 359 /* 360 * Optional routine that allows the transport to decide if a cmd 361 * is retryable. Return true if the transport is in a state the 362 * cmd should be retried on. 363 */ 364 bool (*eh_should_retry_cmd)(struct scsi_cmnd *scmd); 365 366 /* This is an optional routine that allows transport to initiate 367 * LLD adapter or firmware reset using sysfs attribute. 368 * 369 * Return values: 0 on success, -ve value on failure. 370 * 371 * Status: OPTIONAL 372 */ 373 374 int (*host_reset)(struct Scsi_Host *shost, int reset_type); 375 #define SCSI_ADAPTER_RESET 1 376 #define SCSI_FIRMWARE_RESET 2 377 378 379 /* 380 * Name of proc directory 381 */ 382 const char *proc_name; 383 384 /* 385 * This determines if we will use a non-interrupt driven 386 * or an interrupt driven scheme. It is set to the maximum number 387 * of simultaneous commands a single hw queue in HBA will accept 388 * excluding internal commands. 389 */ 390 int can_queue; 391 392 /* 393 * This determines how many commands the HBA will set aside 394 * for internal commands. This number will be added to 395 * @can_queue to calculate the maximum number of simultaneous 396 * commands sent to the host. 397 */ 398 int nr_reserved_cmds; 399 400 /* 401 * In many instances, especially where disconnect / reconnect are 402 * supported, our host also has an ID on the SCSI bus. If this is 403 * the case, then it must be reserved. Please set this_id to -1 if 404 * your setup is in single initiator mode, and the host lacks an 405 * ID. 406 */ 407 int this_id; 408 409 /* 410 * This determines the degree to which the host adapter is capable 411 * of scatter-gather. 412 */ 413 unsigned short sg_tablesize; 414 unsigned short sg_prot_tablesize; 415 416 /* 417 * Set this if the host adapter has limitations beside segment count. 418 */ 419 unsigned int max_sectors; 420 421 /* 422 * Maximum size in bytes of a single segment. 423 */ 424 unsigned int max_segment_size; 425 426 unsigned int dma_alignment; 427 428 /* 429 * DMA scatter gather segment boundary limit. A segment crossing this 430 * boundary will be split in two. 431 */ 432 unsigned long dma_boundary; 433 434 unsigned long virt_boundary_mask; 435 436 /* 437 * This specifies "machine infinity" for host templates which don't 438 * limit the transfer size. Note this limit represents an absolute 439 * maximum, and may be over the transfer limits allowed for 440 * individual devices (e.g. 256 for SCSI-1). 441 */ 442 #define SCSI_DEFAULT_MAX_SECTORS 1024 443 444 /* 445 * True if this host adapter can make good use of linked commands. 446 * This will allow more than one command to be queued to a given 447 * unit on a given host. Set this to the maximum number of command 448 * blocks to be provided for each device. Set this to 1 for one 449 * command block per lun, 2 for two, etc. Do not set this to 0. 450 * You should make sure that the host adapter will do the right thing 451 * before you try setting this above 1. 452 */ 453 short cmd_per_lun; 454 455 /* 456 * Allocate tags starting from last allocated tag. 457 */ 458 bool tag_alloc_policy_rr : 1; 459 460 /* 461 * Track QUEUE_FULL events and reduce queue depth on demand. 462 */ 463 unsigned track_queue_depth:1; 464 465 /* 466 * This specifies the mode that a LLD supports. 467 */ 468 unsigned supported_mode:2; 469 470 /* 471 * True for emulated SCSI host adapters (e.g. ATAPI). 472 */ 473 unsigned emulated:1; 474 475 /* 476 * True if the low-level driver performs its own reset-settle delays. 477 */ 478 unsigned skip_settle_delay:1; 479 480 /* True if the controller does not support WRITE SAME */ 481 unsigned no_write_same:1; 482 483 /* True if the host uses host-wide tagspace */ 484 unsigned host_tagset:1; 485 486 /* The queuecommand callback may block. See also BLK_MQ_F_BLOCKING. */ 487 unsigned queuecommand_may_block:1; 488 489 /* 490 * Countdown for host blocking with no commands outstanding. 491 */ 492 unsigned int max_host_blocked; 493 494 /* 495 * Default value for the blocking. If the queue is empty, 496 * host_blocked counts down in the request_fn until it restarts 497 * host operations as zero is reached. 498 * 499 * FIXME: This should probably be a value in the template 500 */ 501 #define SCSI_DEFAULT_HOST_BLOCKED 7 502 503 /* 504 * Pointer to the SCSI host sysfs attribute groups, NULL terminated. 505 */ 506 const struct attribute_group **shost_groups; 507 508 /* 509 * Pointer to the SCSI device attribute groups for this host, 510 * NULL terminated. 511 */ 512 const struct attribute_group **sdev_groups; 513 514 /* 515 * Vendor Identifier associated with the host 516 * 517 * Note: When specifying vendor_id, be sure to read the 518 * Vendor Type and ID formatting requirements specified in 519 * scsi_netlink.h 520 */ 521 u64 vendor_id; 522 }; 523 524 /* 525 * Temporary #define for host lock push down. Can be removed when all 526 * drivers have been updated to take advantage of unlocked 527 * queuecommand. 528 * 529 */ 530 #define DEF_SCSI_QCMD(func_name) \ 531 enum scsi_qc_status func_name(struct Scsi_Host *shost, \ 532 struct scsi_cmnd *cmd) \ 533 { \ 534 unsigned long irq_flags; \ 535 enum scsi_qc_status rc; \ 536 \ 537 spin_lock_irqsave(shost->host_lock, irq_flags); \ 538 rc = func_name##_lck(cmd); \ 539 spin_unlock_irqrestore(shost->host_lock, irq_flags); \ 540 return rc; \ 541 } 542 543 544 /* 545 * shost state: If you alter this, you also need to alter scsi_sysfs.c 546 * (for the ascii descriptions) and the state model enforcer: 547 * scsi_host_set_state() 548 */ 549 enum scsi_host_state { 550 SHOST_CREATED = 1, 551 SHOST_RUNNING, 552 SHOST_CANCEL, 553 SHOST_DEL, 554 SHOST_RECOVERY, 555 SHOST_CANCEL_RECOVERY, 556 SHOST_DEL_RECOVERY, 557 }; 558 559 struct Scsi_Host { 560 /* 561 * __devices is protected by the host_lock, but you should 562 * usually use scsi_device_lookup / shost_for_each_device 563 * to access it and don't care about locking yourself. 564 * In the rare case of being in irq context you can use 565 * their __ prefixed variants with the lock held. NEVER 566 * access this list directly from a driver. 567 */ 568 struct list_head __devices; 569 struct list_head __targets; 570 571 struct list_head starved_list; 572 573 spinlock_t default_lock; 574 spinlock_t *host_lock; 575 576 struct mutex scan_mutex;/* serialize scanning activity */ 577 578 struct list_head eh_abort_list; 579 struct list_head eh_cmd_q; 580 struct task_struct * ehandler; /* Error recovery thread. */ 581 struct completion * eh_action; /* Wait for specific actions on the 582 host. */ 583 wait_queue_head_t host_wait; 584 const struct scsi_host_template *hostt; 585 struct scsi_transport_template *transportt; 586 587 struct kref tagset_refcnt; 588 struct completion tagset_freed; 589 /* Area to keep a shared tag map */ 590 struct blk_mq_tag_set tag_set; 591 592 atomic_t host_blocked; 593 594 unsigned int host_failed; /* commands that failed. 595 protected by host_lock */ 596 unsigned int host_eh_scheduled; /* EH scheduled without command */ 597 598 unsigned int host_no; /* Used for IOCTL_GET_IDLUN, /proc/scsi et al. */ 599 600 /* next two fields are used to bound the time spent in error handling */ 601 int eh_deadline; 602 unsigned long last_reset; 603 604 605 /* 606 * These three parameters can be used to allow for wide scsi, 607 * and for host adapters that support multiple busses 608 * The last two should be set to 1 more than the actual max id 609 * or lun (e.g. 8 for SCSI parallel systems). 610 */ 611 unsigned int max_channel; 612 unsigned int max_id; 613 u64 max_lun; 614 615 /* 616 * This is a unique identifier that must be assigned so that we 617 * have some way of identifying each detected host adapter properly 618 * and uniquely. For hosts that do not support more than one card 619 * in the system at one time, this does not need to be set. It is 620 * initialized to 0 in scsi_host_alloc. 621 */ 622 unsigned int unique_id; 623 624 /* 625 * The maximum length of SCSI commands that this host can accept. 626 * Probably 12 for most host adapters, but could be 16 for others. 627 * or 260 if the driver supports variable length cdbs. 628 * For drivers that don't set this field, a value of 12 is 629 * assumed. 630 */ 631 unsigned short max_cmd_len; 632 633 int this_id; 634 635 /* 636 * Number of commands this host can handle at the same time. 637 * This excludes reserved commands as specified by nr_reserved_cmds. 638 */ 639 int can_queue; 640 /* 641 * Number of reserved commands to allocate, if any. 642 */ 643 unsigned int nr_reserved_cmds; 644 645 short cmd_per_lun; 646 short unsigned int sg_tablesize; 647 short unsigned int sg_prot_tablesize; 648 unsigned int max_sectors; 649 unsigned int opt_sectors; 650 unsigned int max_segment_size; 651 unsigned int dma_alignment; 652 unsigned long dma_boundary; 653 unsigned long virt_boundary_mask; 654 /* 655 * In scsi-mq mode, the number of hardware queues supported by the LLD. 656 * 657 * Note: it is assumed that each hardware queue has a queue depth of 658 * can_queue. In other words, the total queue depth per host 659 * is nr_hw_queues * can_queue. However, for when host_tagset is set, 660 * the total queue depth is can_queue. 661 */ 662 unsigned nr_hw_queues; 663 unsigned nr_maps; 664 665 /* Asynchronous scan in progress */ 666 bool async_scan __guarded_by(&scan_mutex); 667 668 unsigned active_mode:2; 669 670 /* 671 * Host has requested that no further requests come through for the 672 * time being. 673 */ 674 unsigned host_self_blocked:1; 675 676 /* 677 * Host uses correct SCSI ordering not PC ordering. The bit is 678 * set for the minority of drivers whose authors actually read 679 * the spec ;). 680 */ 681 unsigned reverse_ordering:1; 682 683 /* Task mgmt function in progress */ 684 unsigned tmf_in_progress:1; 685 686 /* Don't resume host in EH */ 687 unsigned eh_noresume:1; 688 689 /* The controller does not support WRITE SAME */ 690 unsigned no_write_same:1; 691 692 /* True if the host uses host-wide tagspace */ 693 unsigned host_tagset:1; 694 695 /* The queuecommand callback may block. See also BLK_MQ_F_BLOCKING. */ 696 unsigned queuecommand_may_block:1; 697 698 /* Host responded with short (<36 bytes) INQUIRY result */ 699 unsigned short_inquiry:1; 700 701 /* The transport requires the LUN bits NOT to be stored in CDB[1] */ 702 unsigned no_scsi2_lun_in_cdb:1; 703 704 /* 705 * Optional work queue to be utilized by the transport 706 */ 707 struct workqueue_struct *work_q; 708 709 /* 710 * Task management function work queue 711 */ 712 struct workqueue_struct *tmf_work_q; 713 714 /* 715 * Value host_blocked counts down from 716 */ 717 unsigned int max_host_blocked; 718 719 /* Protection Information */ 720 unsigned int prot_capabilities; 721 unsigned char prot_guard_type; 722 723 /* legacy crap */ 724 unsigned long base; 725 unsigned long io_port; 726 unsigned char n_io_port; 727 unsigned char dma_channel; 728 unsigned int irq; 729 730 731 enum scsi_host_state shost_state __guarded_by(host_lock); 732 733 /* ldm bits */ 734 struct device shost_gendev, shost_dev; 735 736 /* 737 * A SCSI device structure used for sending internal commands to the 738 * HBA. There is no corresponding logical unit inside the SCSI device. 739 */ 740 struct scsi_device *pseudo_sdev; 741 742 /* 743 * Points to the transport data (if any) which is allocated 744 * separately 745 */ 746 void *shost_data; 747 748 /* 749 * Points to the physical bus device we'd use to do DMA 750 * Needed just in case we have virtual hosts. 751 */ 752 struct device *dma_dev; 753 754 /* Delay for runtime autosuspend */ 755 int rpm_autosuspend_delay; 756 757 /* 758 * We should ensure that this is aligned, both for better performance 759 * and also because some compilers (m68k) don't automatically force 760 * alignment to a long boundary. 761 */ 762 unsigned long hostdata[] /* Used for storage of host specific stuff */ 763 __attribute__ ((aligned (sizeof(unsigned long)))); 764 }; 765 766 #define class_to_shost(d) \ 767 container_of(d, struct Scsi_Host, shost_dev) 768 769 #define shost_printk(prefix, shost, fmt, a...) \ 770 dev_printk(prefix, &(shost)->shost_gendev, fmt, ##a) 771 772 static inline void *shost_priv(struct Scsi_Host *shost) 773 { 774 return (void *)shost->hostdata; 775 } 776 777 int scsi_is_host_device(const struct device *); 778 779 static inline struct Scsi_Host *dev_to_shost(struct device *dev) 780 { 781 while (!scsi_is_host_device(dev)) { 782 if (!dev->parent) 783 return NULL; 784 dev = dev->parent; 785 } 786 return container_of(dev, struct Scsi_Host, shost_gendev); 787 } 788 789 static inline enum scsi_host_state scsi_get_host_state(struct Scsi_Host *shost) 790 { 791 return context_unsafe(READ_ONCE(shost->shost_state)); 792 } 793 794 static inline int scsi_host_in_recovery(struct Scsi_Host *shost) 795 { 796 enum scsi_host_state state = scsi_get_host_state(shost); 797 798 return state == SHOST_RECOVERY || 799 state == SHOST_CANCEL_RECOVERY || 800 state == SHOST_DEL_RECOVERY || 801 shost->tmf_in_progress; 802 } 803 804 extern int scsi_queue_work(struct Scsi_Host *, struct work_struct *); 805 extern void scsi_flush_work(struct Scsi_Host *); 806 807 extern struct Scsi_Host *scsi_host_alloc(const struct scsi_host_template *, int); 808 extern int __must_check scsi_add_host_with_dma(struct Scsi_Host *, 809 struct device *, 810 struct device *); 811 #if defined(CONFIG_SCSI_PROC_FS) 812 struct proc_dir_entry * 813 scsi_template_proc_dir(const struct scsi_host_template *sht); 814 #else 815 #define scsi_template_proc_dir(sht) NULL 816 #endif 817 extern void scsi_scan_host(struct Scsi_Host *); 818 extern int scsi_resume_device(struct scsi_device *sdev); 819 extern int scsi_rescan_device(struct scsi_device *sdev); 820 extern void scsi_remove_host(struct Scsi_Host *); 821 extern struct Scsi_Host *scsi_host_get(struct Scsi_Host *); 822 extern int scsi_host_busy(struct Scsi_Host *shost); 823 extern void scsi_host_put(struct Scsi_Host *t); 824 extern struct Scsi_Host *scsi_host_lookup(unsigned int hostnum); 825 extern const char *scsi_host_state_name(enum scsi_host_state); 826 extern void scsi_host_complete_all_commands(struct Scsi_Host *shost, 827 enum scsi_host_status status); 828 829 static inline int __must_check scsi_add_host(struct Scsi_Host *host, 830 struct device *dev) 831 { 832 return scsi_add_host_with_dma(host, dev, dev); 833 } 834 835 static inline struct device *scsi_get_device(struct Scsi_Host *shost) 836 { 837 return shost->shost_gendev.parent; 838 } 839 840 /** 841 * scsi_host_scan_allowed - Is scanning of this host allowed 842 * @shost: Pointer to Scsi_Host. 843 **/ 844 static inline int scsi_host_scan_allowed(struct Scsi_Host *shost) 845 { 846 enum scsi_host_state state = scsi_get_host_state(shost); 847 848 return state == SHOST_RUNNING || state == SHOST_RECOVERY; 849 } 850 851 extern void scsi_unblock_requests(struct Scsi_Host *); 852 extern void scsi_block_requests(struct Scsi_Host *); 853 extern int scsi_host_block(struct Scsi_Host *shost); 854 extern int scsi_host_unblock(struct Scsi_Host *shost, int new_state); 855 856 void scsi_host_busy_iter(struct Scsi_Host *, 857 bool (*fn)(struct scsi_cmnd *, void *), void *priv); 858 859 struct class_container; 860 861 /* 862 * DIF defines the exchange of protection information between 863 * initiator and SBC block device. 864 * 865 * DIX defines the exchange of protection information between OS and 866 * initiator. 867 */ 868 enum scsi_host_prot_capabilities { 869 SHOST_DIF_TYPE1_PROTECTION = 1 << 0, /* T10 DIF Type 1 */ 870 SHOST_DIF_TYPE2_PROTECTION = 1 << 1, /* T10 DIF Type 2 */ 871 SHOST_DIF_TYPE3_PROTECTION = 1 << 2, /* T10 DIF Type 3 */ 872 873 SHOST_DIX_TYPE0_PROTECTION = 1 << 3, /* DIX between OS and HBA only */ 874 SHOST_DIX_TYPE1_PROTECTION = 1 << 4, /* DIX with DIF Type 1 */ 875 SHOST_DIX_TYPE2_PROTECTION = 1 << 5, /* DIX with DIF Type 2 */ 876 SHOST_DIX_TYPE3_PROTECTION = 1 << 6, /* DIX with DIF Type 3 */ 877 }; 878 879 /* 880 * SCSI hosts which support the Data Integrity Extensions must 881 * indicate their capabilities by setting the prot_capabilities using 882 * this call. 883 */ 884 static inline void scsi_host_set_prot(struct Scsi_Host *shost, unsigned int mask) 885 { 886 shost->prot_capabilities = mask; 887 } 888 889 static inline unsigned int scsi_host_get_prot(struct Scsi_Host *shost) 890 { 891 return shost->prot_capabilities; 892 } 893 894 static inline int scsi_host_prot_dma(struct Scsi_Host *shost) 895 { 896 return shost->prot_capabilities >= SHOST_DIX_TYPE0_PROTECTION; 897 } 898 899 static inline unsigned int scsi_host_dif_capable(struct Scsi_Host *shost, unsigned int target_type) 900 { 901 static unsigned char cap[] = { 0, 902 SHOST_DIF_TYPE1_PROTECTION, 903 SHOST_DIF_TYPE2_PROTECTION, 904 SHOST_DIF_TYPE3_PROTECTION }; 905 906 if (target_type >= ARRAY_SIZE(cap)) 907 return 0; 908 909 return shost->prot_capabilities & cap[target_type] ? target_type : 0; 910 } 911 912 static inline unsigned int scsi_host_dix_capable(struct Scsi_Host *shost, unsigned int target_type) 913 { 914 #if defined(CONFIG_BLK_DEV_INTEGRITY) 915 static unsigned char cap[] = { SHOST_DIX_TYPE0_PROTECTION, 916 SHOST_DIX_TYPE1_PROTECTION, 917 SHOST_DIX_TYPE2_PROTECTION, 918 SHOST_DIX_TYPE3_PROTECTION }; 919 920 if (target_type >= ARRAY_SIZE(cap)) 921 return 0; 922 923 return shost->prot_capabilities & cap[target_type]; 924 #endif 925 return 0; 926 } 927 928 /* 929 * All DIX-capable initiators must support the T10-mandated CRC 930 * checksum. Controllers can optionally implement the IP checksum 931 * scheme which has much lower impact on system performance. Note 932 * that the main rationale for the checksum is to match integrity 933 * metadata with data. Detecting bit errors are a job for ECC memory 934 * and buses. 935 */ 936 937 enum scsi_host_guard_type { 938 SHOST_DIX_GUARD_CRC = 1 << 0, 939 SHOST_DIX_GUARD_IP = 1 << 1, 940 }; 941 942 static inline void scsi_host_set_guard(struct Scsi_Host *shost, unsigned char type) 943 { 944 shost->prot_guard_type = type; 945 } 946 947 static inline unsigned char scsi_host_get_guard(struct Scsi_Host *shost) 948 { 949 return shost->prot_guard_type; 950 } 951 952 int scsi_host_set_state(struct Scsi_Host *shost, enum scsi_host_state state) 953 __must_hold(shost->host_lock); 954 955 #endif /* _SCSI_SCSI_HOST_H */ 956