/* SPDX-License-Identifier: GPL-2.0 */ #ifndef _SCSI_SCSI_HOST_H #define _SCSI_SCSI_HOST_H #include <linux/device.h> #include <linux/list.h> #include <linux/types.h> #include <linux/workqueue.h> #include <linux/mutex.h> #include <linux/seq_file.h> #include <linux/blk-mq.h> #include <scsi/scsi.h> struct block_device; struct completion; struct module; struct scsi_cmnd; struct scsi_device; struct scsi_target; struct Scsi_Host; struct scsi_transport_template; #define SG_ALL SG_CHUNK_SIZE #define MODE_UNKNOWN 0x00 #define MODE_INITIATOR 0x01 #define MODE_TARGET 0x02 /** * enum scsi_timeout_action - How to handle a command that timed out. * @SCSI_EH_DONE: The command has already been completed. * @SCSI_EH_RESET_TIMER: Reset the timer and continue waiting for completion. * @SCSI_EH_NOT_HANDLED: The command has not yet finished. Abort the command. */ enum scsi_timeout_action { SCSI_EH_DONE, SCSI_EH_RESET_TIMER, SCSI_EH_NOT_HANDLED, }; struct scsi_host_template { /* * Put fields referenced in IO submission path together in * same cacheline */ /* * Additional per-command data allocated for the driver. */ unsigned int cmd_size; /* * The queuecommand function is used to queue up a scsi * command block to the LLDD. When the driver finished * processing the command the done callback is invoked. * * If queuecommand returns 0, then the driver has accepted the * command. It must also push it to the HBA if the scsi_cmnd * flag SCMD_LAST is set, or if the driver does not implement * commit_rqs. The done() function must be called on the command * when the driver has finished with it. (you may call done on the * command before queuecommand returns, but in this case you * *must* return 0 from queuecommand). * * Queuecommand may also reject the command, in which case it may * not touch the command and must not call done() for it. * * There are two possible rejection returns: * * SCSI_MLQUEUE_DEVICE_BUSY: Block this device temporarily, but * allow commands to other devices serviced by this host. * * SCSI_MLQUEUE_HOST_BUSY: Block all devices served by this * host temporarily. * * For compatibility, any other non-zero return is treated the * same as SCSI_MLQUEUE_HOST_BUSY. * * NOTE: "temporarily" means either until the next command for# * this device/host completes, or a period of time determined by * I/O pressure in the system if there are no other outstanding * commands. * * STATUS: REQUIRED */ int (* queuecommand)(struct Scsi_Host *, struct scsi_cmnd *); /* * The commit_rqs function is used to trigger a hardware * doorbell after some requests have been queued with * queuecommand, when an error is encountered before sending * the request with SCMD_LAST set. * * STATUS: OPTIONAL */ void (*commit_rqs)(struct Scsi_Host *, u16); struct module *module; const char *name; /* * The info function will return whatever useful information the * developer sees fit. If not provided, then the name field will * be used instead. * * Status: OPTIONAL */ const char *(*info)(struct Scsi_Host *); /* * Ioctl interface * * Status: OPTIONAL */ int (*ioctl)(struct scsi_device *dev, unsigned int cmd, void __user *arg); #ifdef CONFIG_COMPAT /* * Compat handler. Handle 32bit ABI. * When unknown ioctl is passed return -ENOIOCTLCMD. * * Status: OPTIONAL */ int (*compat_ioctl)(struct scsi_device *dev, unsigned int cmd, void __user *arg); #endif int (*init_cmd_priv)(struct Scsi_Host *shost, struct scsi_cmnd *cmd); int (*exit_cmd_priv)(struct Scsi_Host *shost, struct scsi_cmnd *cmd); /* * This is an error handling strategy routine. You don't need to * define one of these if you don't want to - there is a default * routine that is present that should work in most cases. For those * driver authors that have the inclination and ability to write their * own strategy routine, this is where it is specified. Note - the * strategy routine is *ALWAYS* run in the context of the kernel eh * thread. Thus you are guaranteed to *NOT* be in an interrupt * handler when you execute this, and you are also guaranteed to * *NOT* have any other commands being queued while you are in the * strategy routine. When you return from this function, operations * return to normal. * * See scsi_error.c scsi_unjam_host for additional comments about * what this function should and should not be attempting to do. * * Status: REQUIRED (at least one of them) */ int (* eh_abort_handler)(struct scsi_cmnd *); int (* eh_device_reset_handler)(struct scsi_cmnd *); int (* eh_target_reset_handler)(struct scsi_cmnd *); int (* eh_bus_reset_handler)(struct scsi_cmnd *); int (* eh_host_reset_handler)(struct scsi_cmnd *); /* * Before the mid layer attempts to scan for a new device where none * currently exists, it will call this entry in your driver. Should * your driver need to allocate any structs or perform any other init * items in order to send commands to a currently unused target/lun * combo, then this is where you can perform those allocations. This * is specifically so that drivers won't have to perform any kind of * "is this a new device" checks in their queuecommand routine, * thereby making the hot path a bit quicker. * * Return values: 0 on success, non-0 on failure * * Deallocation: If we didn't find any devices at this ID, you will * get an immediate call to slave_destroy(). If we find something * here then you will get a call to slave_configure(), then the * device will be used for however long it is kept around, then when * the device is removed from the system (or * possibly at reboot * time), you will then get a call to slave_destroy(). This is * assuming you implement slave_configure and slave_destroy. * However, if you allocate memory and hang it off the device struct, * then you must implement the slave_destroy() routine at a minimum * in order to avoid leaking memory * each time a device is tore down. * * Status: OPTIONAL */ int (* slave_alloc)(struct scsi_device *); /* * Once the device has responded to an INQUIRY and we know the * device is online, we call into the low level driver with the * struct scsi_device *. If the low level device driver implements * this function, it *must* perform the task of setting the queue * depth on the device. All other tasks are optional and depend * on what the driver supports and various implementation details. * * Things currently recommended to be handled at this time include: * * 1. Setting the device queue depth. Proper setting of this is * described in the comments for scsi_change_queue_depth. * 2. Determining if the device supports the various synchronous * negotiation protocols. The device struct will already have * responded to INQUIRY and the results of the standard items * will have been shoved into the various device flag bits, eg. * device->sdtr will be true if the device supports SDTR messages. * 3. Allocating command structs that the device will need. * 4. Setting the default timeout on this device (if needed). * 5. Anything else the low level driver might want to do on a device * specific setup basis... * 6. Return 0 on success, non-0 on error. The device will be marked * as offline on error so that no access will occur. If you return * non-0, your slave_destroy routine will never get called for this * device, so don't leave any loose memory hanging around, clean * up after yourself before returning non-0 * * Status: OPTIONAL */ int (* slave_configure)(struct scsi_device *); /* * Immediately prior to deallocating the device and after all activity * has ceased the mid layer calls this point so that the low level * driver may completely detach itself from the scsi device and vice * versa. The low level driver is responsible for freeing any memory * it allocated in the slave_alloc or slave_configure calls. * * Status: OPTIONAL */ void (* slave_destroy)(struct scsi_device *); /* * Before the mid layer attempts to scan for a new device attached * to a target where no target currently exists, it will call this * entry in your driver. Should your driver need to allocate any * structs or perform any other init items in order to send commands * to a currently unused target, then this is where you can perform * those allocations. * * Return values: 0 on success, non-0 on failure * * Status: OPTIONAL */ int (* target_alloc)(struct scsi_target *); /* * Immediately prior to deallocating the target structure, and * after all activity to attached scsi devices has ceased, the * midlayer calls this point so that the driver may deallocate * and terminate any references to the target. * * Status: OPTIONAL */ void (* target_destroy)(struct scsi_target *); /* * If a host has the ability to discover targets on its own instead * of scanning the entire bus, it can fill in this function and * call scsi_scan_host(). This function will be called periodically * until it returns 1 with the scsi_host and the elapsed time of * the scan in jiffies. * * Status: OPTIONAL */ int (* scan_finished)(struct Scsi_Host *, unsigned long); /* * If the host wants to be called before the scan starts, but * after the midlayer has set up ready for the scan, it can fill * in this function. * * Status: OPTIONAL */ void (* scan_start)(struct Scsi_Host *); /* * Fill in this function to allow the queue depth of this host * to be changeable (on a per device basis). Returns either * the current queue depth setting (may be different from what * was passed in) or an error. An error should only be * returned if the requested depth is legal but the driver was * unable to set it. If the requested depth is illegal, the * driver should set and return the closest legal queue depth. * * Status: OPTIONAL */ int (* change_queue_depth)(struct scsi_device *, int); /* * This functions lets the driver expose the queue mapping * to the block layer. * * Status: OPTIONAL */ void (* map_queues)(struct Scsi_Host *shost); /* * SCSI interface of blk_poll - poll for IO completions. * Only applicable if SCSI LLD exposes multiple h/w queues. * * Return value: Number of completed entries found. * * Status: OPTIONAL */ int (* mq_poll)(struct Scsi_Host *shost, unsigned int queue_num); /* * Check if scatterlists need to be padded for DMA draining. * * Status: OPTIONAL */ bool (* dma_need_drain)(struct request *rq); /* * This function determines the BIOS parameters for a given * harddisk. These tend to be numbers that are made up by * the host adapter. Parameters: * size, device, list (heads, sectors, cylinders) * * Status: OPTIONAL */ int (* bios_param)(struct scsi_device *, struct block_device *, sector_t, int []); /* * This function is called when one or more partitions on the * device reach beyond the end of the device. * * Status: OPTIONAL */ void (*unlock_native_capacity)(struct scsi_device *); /* * Can be used to export driver statistics and other infos to the * world outside the kernel ie. userspace and it also provides an * interface to feed the driver with information. * * Status: OBSOLETE */ int (*show_info)(struct seq_file *, struct Scsi_Host *); int (*write_info)(struct Scsi_Host *, char *, int); /* * This is an optional routine that allows the transport to become * involved when a scsi io timer fires. The return value tells the * timer routine how to finish the io timeout handling. * * Status: OPTIONAL */ enum scsi_timeout_action (*eh_timed_out)(struct scsi_cmnd *); /* * Optional routine that allows the transport to decide if a cmd * is retryable. Return true if the transport is in a state the * cmd should be retried on. */ bool (*eh_should_retry_cmd)(struct scsi_cmnd *scmd); /* This is an optional routine that allows transport to initiate * LLD adapter or firmware reset using sysfs attribute. * * Return values: 0 on success, -ve value on failure. * * Status: OPTIONAL */ int (*host_reset)(struct Scsi_Host *shost, int reset_type); #define SCSI_ADAPTER_RESET 1 #define SCSI_FIRMWARE_RESET 2 /* * Name of proc directory */ const char *proc_name; /* * This determines if we will use a non-interrupt driven * or an interrupt driven scheme. It is set to the maximum number * of simultaneous commands a single hw queue in HBA will accept. */ int can_queue; /* * In many instances, especially where disconnect / reconnect are * supported, our host also has an ID on the SCSI bus. If this is * the case, then it must be reserved. Please set this_id to -1 if * your setup is in single initiator mode, and the host lacks an * ID. */ int this_id; /* * This determines the degree to which the host adapter is capable * of scatter-gather. */ unsigned short sg_tablesize; unsigned short sg_prot_tablesize; /* * Set this if the host adapter has limitations beside segment count. */ unsigned int max_sectors; /* * Maximum size in bytes of a single segment. */ unsigned int max_segment_size; /* * DMA scatter gather segment boundary limit. A segment crossing this * boundary will be split in two. */ unsigned long dma_boundary; unsigned long virt_boundary_mask; /* * This specifies "machine infinity" for host templates which don't * limit the transfer size. Note this limit represents an absolute * maximum, and may be over the transfer limits allowed for * individual devices (e.g. 256 for SCSI-1). */ #define SCSI_DEFAULT_MAX_SECTORS 1024 /* * True if this host adapter can make good use of linked commands. * This will allow more than one command to be queued to a given * unit on a given host. Set this to the maximum number of command * blocks to be provided for each device. Set this to 1 for one * command block per lun, 2 for two, etc. Do not set this to 0. * You should make sure that the host adapter will do the right thing * before you try setting this above 1. */ short cmd_per_lun; /* If use block layer to manage tags, this is tag allocation policy */ int tag_alloc_policy; /* * Track QUEUE_FULL events and reduce queue depth on demand. */ unsigned track_queue_depth:1; /* * This specifies the mode that a LLD supports. */ unsigned supported_mode:2; /* * True for emulated SCSI host adapters (e.g. ATAPI). */ unsigned emulated:1; /* * True if the low-level driver performs its own reset-settle delays. */ unsigned skip_settle_delay:1; /* True if the controller does not support WRITE SAME */ unsigned no_write_same:1; /* True if the host uses host-wide tagspace */ unsigned host_tagset:1; /* The queuecommand callback may block. See also BLK_MQ_F_BLOCKING. */ unsigned queuecommand_may_block:1; /* * Countdown for host blocking with no commands outstanding. */ unsigned int max_host_blocked; /* * Default value for the blocking. If the queue is empty, * host_blocked counts down in the request_fn until it restarts * host operations as zero is reached. * * FIXME: This should probably be a value in the template */ #define SCSI_DEFAULT_HOST_BLOCKED 7 /* * Pointer to the SCSI host sysfs attribute groups, NULL terminated. */ const struct attribute_group **shost_groups; /* * Pointer to the SCSI device attribute groups for this host, * NULL terminated. */ const struct attribute_group **sdev_groups; /* * Vendor Identifier associated with the host * * Note: When specifying vendor_id, be sure to read the * Vendor Type and ID formatting requirements specified in * scsi_netlink.h */ u64 vendor_id; /* Delay for runtime autosuspend */ int rpm_autosuspend_delay; }; /* * Temporary #define for host lock push down. Can be removed when all * drivers have been updated to take advantage of unlocked * queuecommand. * */ #define DEF_SCSI_QCMD(func_name) \ int func_name(struct Scsi_Host *shost, struct scsi_cmnd *cmd) \ { \ unsigned long irq_flags; \ int rc; \ spin_lock_irqsave(shost->host_lock, irq_flags); \ rc = func_name##_lck(cmd); \ spin_unlock_irqrestore(shost->host_lock, irq_flags); \ return rc; \ } /* * shost state: If you alter this, you also need to alter scsi_sysfs.c * (for the ascii descriptions) and the state model enforcer: * scsi_host_set_state() */ enum scsi_host_state { SHOST_CREATED = 1, SHOST_RUNNING, SHOST_CANCEL, SHOST_DEL, SHOST_RECOVERY, SHOST_CANCEL_RECOVERY, SHOST_DEL_RECOVERY, }; struct Scsi_Host { /* * __devices is protected by the host_lock, but you should * usually use scsi_device_lookup / shost_for_each_device * to access it and don't care about locking yourself. * In the rare case of being in irq context you can use * their __ prefixed variants with the lock held. NEVER * access this list directly from a driver. */ struct list_head __devices; struct list_head __targets; struct list_head starved_list; spinlock_t default_lock; spinlock_t *host_lock; struct mutex scan_mutex;/* serialize scanning activity */ struct list_head eh_abort_list; struct list_head eh_cmd_q; struct task_struct * ehandler; /* Error recovery thread. */ struct completion * eh_action; /* Wait for specific actions on the host. */ wait_queue_head_t host_wait; const struct scsi_host_template *hostt; struct scsi_transport_template *transportt; struct kref tagset_refcnt; struct completion tagset_freed; /* Area to keep a shared tag map */ struct blk_mq_tag_set tag_set; atomic_t host_blocked; unsigned int host_failed; /* commands that failed. protected by host_lock */ unsigned int host_eh_scheduled; /* EH scheduled without command */ unsigned int host_no; /* Used for IOCTL_GET_IDLUN, /proc/scsi et al. */ /* next two fields are used to bound the time spent in error handling */ int eh_deadline; unsigned long last_reset; /* * These three parameters can be used to allow for wide scsi, * and for host adapters that support multiple busses * The last two should be set to 1 more than the actual max id * or lun (e.g. 8 for SCSI parallel systems). */ unsigned int max_channel; unsigned int max_id; u64 max_lun; /* * This is a unique identifier that must be assigned so that we * have some way of identifying each detected host adapter properly * and uniquely. For hosts that do not support more than one card * in the system at one time, this does not need to be set. It is * initialized to 0 in scsi_register. */ unsigned int unique_id; /* * The maximum length of SCSI commands that this host can accept. * Probably 12 for most host adapters, but could be 16 for others. * or 260 if the driver supports variable length cdbs. * For drivers that don't set this field, a value of 12 is * assumed. */ unsigned short max_cmd_len; int this_id; int can_queue; short cmd_per_lun; short unsigned int sg_tablesize; short unsigned int sg_prot_tablesize; unsigned int max_sectors; unsigned int opt_sectors; unsigned int max_segment_size; unsigned long dma_boundary; unsigned long virt_boundary_mask; /* * In scsi-mq mode, the number of hardware queues supported by the LLD. * * Note: it is assumed that each hardware queue has a queue depth of * can_queue. In other words, the total queue depth per host * is nr_hw_queues * can_queue. However, for when host_tagset is set, * the total queue depth is can_queue. */ unsigned nr_hw_queues; unsigned nr_maps; unsigned active_mode:2; /* * Host has requested that no further requests come through for the * time being. */ unsigned host_self_blocked:1; /* * Host uses correct SCSI ordering not PC ordering. The bit is * set for the minority of drivers whose authors actually read * the spec ;). */ unsigned reverse_ordering:1; /* Task mgmt function in progress */ unsigned tmf_in_progress:1; /* Asynchronous scan in progress */ unsigned async_scan:1; /* Don't resume host in EH */ unsigned eh_noresume:1; /* The controller does not support WRITE SAME */ unsigned no_write_same:1; /* True if the host uses host-wide tagspace */ unsigned host_tagset:1; /* The queuecommand callback may block. See also BLK_MQ_F_BLOCKING. */ unsigned queuecommand_may_block:1; /* Host responded with short (<36 bytes) INQUIRY result */ unsigned short_inquiry:1; /* The transport requires the LUN bits NOT to be stored in CDB[1] */ unsigned no_scsi2_lun_in_cdb:1; /* * Optional work queue to be utilized by the transport */ char work_q_name[20]; struct workqueue_struct *work_q; /* * Task management function work queue */ struct workqueue_struct *tmf_work_q; /* * Value host_blocked counts down from */ unsigned int max_host_blocked; /* Protection Information */ unsigned int prot_capabilities; unsigned char prot_guard_type; /* legacy crap */ unsigned long base; unsigned long io_port; unsigned char n_io_port; unsigned char dma_channel; unsigned int irq; enum scsi_host_state shost_state; /* ldm bits */ struct device shost_gendev, shost_dev; /* * Points to the transport data (if any) which is allocated * separately */ void *shost_data; /* * Points to the physical bus device we'd use to do DMA * Needed just in case we have virtual hosts. */ struct device *dma_dev; /* * We should ensure that this is aligned, both for better performance * and also because some compilers (m68k) don't automatically force * alignment to a long boundary. */ unsigned long hostdata[] /* Used for storage of host specific stuff */ __attribute__ ((aligned (sizeof(unsigned long)))); }; #define class_to_shost(d) \ container_of(d, struct Scsi_Host, shost_dev) #define shost_printk(prefix, shost, fmt, a...) \ dev_printk(prefix, &(shost)->shost_gendev, fmt, ##a) static inline void *shost_priv(struct Scsi_Host *shost) { return (void *)shost->hostdata; } int scsi_is_host_device(const struct device *); static inline struct Scsi_Host *dev_to_shost(struct device *dev) { while (!scsi_is_host_device(dev)) { if (!dev->parent) return NULL; dev = dev->parent; } return container_of(dev, struct Scsi_Host, shost_gendev); } static inline int scsi_host_in_recovery(struct Scsi_Host *shost) { return shost->shost_state == SHOST_RECOVERY || shost->shost_state == SHOST_CANCEL_RECOVERY || shost->shost_state == SHOST_DEL_RECOVERY || shost->tmf_in_progress; } extern int scsi_queue_work(struct Scsi_Host *, struct work_struct *); extern void scsi_flush_work(struct Scsi_Host *); extern struct Scsi_Host *scsi_host_alloc(const struct scsi_host_template *, int); extern int __must_check scsi_add_host_with_dma(struct Scsi_Host *, struct device *, struct device *); #if defined(CONFIG_SCSI_PROC_FS) struct proc_dir_entry * scsi_template_proc_dir(const struct scsi_host_template *sht); #else #define scsi_template_proc_dir(sht) NULL #endif extern void scsi_scan_host(struct Scsi_Host *); extern int scsi_rescan_device(struct scsi_device *sdev); extern void scsi_remove_host(struct Scsi_Host *); extern struct Scsi_Host *scsi_host_get(struct Scsi_Host *); extern int scsi_host_busy(struct Scsi_Host *shost); extern void scsi_host_put(struct Scsi_Host *t); extern struct Scsi_Host *scsi_host_lookup(unsigned int hostnum); extern const char *scsi_host_state_name(enum scsi_host_state); extern void scsi_host_complete_all_commands(struct Scsi_Host *shost, enum scsi_host_status status); static inline int __must_check scsi_add_host(struct Scsi_Host *host, struct device *dev) { return scsi_add_host_with_dma(host, dev, dev); } static inline struct device *scsi_get_device(struct Scsi_Host *shost) { return shost->shost_gendev.parent; } /** * scsi_host_scan_allowed - Is scanning of this host allowed * @shost: Pointer to Scsi_Host. **/ static inline int scsi_host_scan_allowed(struct Scsi_Host *shost) { return shost->shost_state == SHOST_RUNNING || shost->shost_state == SHOST_RECOVERY; } extern void scsi_unblock_requests(struct Scsi_Host *); extern void scsi_block_requests(struct Scsi_Host *); extern int scsi_host_block(struct Scsi_Host *shost); extern int scsi_host_unblock(struct Scsi_Host *shost, int new_state); void scsi_host_busy_iter(struct Scsi_Host *, bool (*fn)(struct scsi_cmnd *, void *), void *priv); struct class_container; /* * DIF defines the exchange of protection information between * initiator and SBC block device. * * DIX defines the exchange of protection information between OS and * initiator. */ enum scsi_host_prot_capabilities { SHOST_DIF_TYPE1_PROTECTION = 1 << 0, /* T10 DIF Type 1 */ SHOST_DIF_TYPE2_PROTECTION = 1 << 1, /* T10 DIF Type 2 */ SHOST_DIF_TYPE3_PROTECTION = 1 << 2, /* T10 DIF Type 3 */ SHOST_DIX_TYPE0_PROTECTION = 1 << 3, /* DIX between OS and HBA only */ SHOST_DIX_TYPE1_PROTECTION = 1 << 4, /* DIX with DIF Type 1 */ SHOST_DIX_TYPE2_PROTECTION = 1 << 5, /* DIX with DIF Type 2 */ SHOST_DIX_TYPE3_PROTECTION = 1 << 6, /* DIX with DIF Type 3 */ }; /* * SCSI hosts which support the Data Integrity Extensions must * indicate their capabilities by setting the prot_capabilities using * this call. */ static inline void scsi_host_set_prot(struct Scsi_Host *shost, unsigned int mask) { shost->prot_capabilities = mask; } static inline unsigned int scsi_host_get_prot(struct Scsi_Host *shost) { return shost->prot_capabilities; } static inline int scsi_host_prot_dma(struct Scsi_Host *shost) { return shost->prot_capabilities >= SHOST_DIX_TYPE0_PROTECTION; } static inline unsigned int scsi_host_dif_capable(struct Scsi_Host *shost, unsigned int target_type) { static unsigned char cap[] = { 0, SHOST_DIF_TYPE1_PROTECTION, SHOST_DIF_TYPE2_PROTECTION, SHOST_DIF_TYPE3_PROTECTION }; if (target_type >= ARRAY_SIZE(cap)) return 0; return shost->prot_capabilities & cap[target_type] ? target_type : 0; } static inline unsigned int scsi_host_dix_capable(struct Scsi_Host *shost, unsigned int target_type) { #if defined(CONFIG_BLK_DEV_INTEGRITY) static unsigned char cap[] = { SHOST_DIX_TYPE0_PROTECTION, SHOST_DIX_TYPE1_PROTECTION, SHOST_DIX_TYPE2_PROTECTION, SHOST_DIX_TYPE3_PROTECTION }; if (target_type >= ARRAY_SIZE(cap)) return 0; return shost->prot_capabilities & cap[target_type]; #endif return 0; } /* * All DIX-capable initiators must support the T10-mandated CRC * checksum. Controllers can optionally implement the IP checksum * scheme which has much lower impact on system performance. Note * that the main rationale for the checksum is to match integrity * metadata with data. Detecting bit errors are a job for ECC memory * and buses. */ enum scsi_host_guard_type { SHOST_DIX_GUARD_CRC = 1 << 0, SHOST_DIX_GUARD_IP = 1 << 1, }; static inline void scsi_host_set_guard(struct Scsi_Host *shost, unsigned char type) { shost->prot_guard_type = type; } static inline unsigned char scsi_host_get_guard(struct Scsi_Host *shost) { return shost->prot_guard_type; } extern int scsi_host_set_state(struct Scsi_Host *, enum scsi_host_state); #endif /* _SCSI_SCSI_HOST_H */