| #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> |
| |
| struct block_device; |
| struct module; |
| struct scsi_cmnd; |
| struct scsi_device; |
| struct scsi_target; |
| struct Scsi_Host; |
| struct scsi_host_cmd_pool; |
| struct scsi_transport_template; |
| |
| |
| /* |
| * The various choices mean: |
| * NONE: Self evident. Host adapter is not capable of scatter-gather. |
| * ALL: Means that the host adapter module can do scatter-gather, |
| * and that there is no limit to the size of the table to which |
| * we scatter/gather data. |
| * Anything else: Indicates the maximum number of chains that can be |
| * used in one scatter-gather request. |
| */ |
| #define SG_NONE 0 |
| #define SG_ALL 0xff |
| |
| |
| #define DISABLE_CLUSTERING 0 |
| #define ENABLE_CLUSTERING 1 |
| |
| enum scsi_eh_timer_return { |
| EH_NOT_HANDLED, |
| EH_HANDLED, |
| EH_RESET_TIMER, |
| }; |
| |
| |
| struct scsi_host_template { |
| struct module *module; |
| const char *name; |
| |
| /* |
| * Used to initialize old-style drivers. For new-style drivers |
| * just perform all work in your module initialization function. |
| * |
| * Status: OBSOLETE |
| */ |
| int (* detect)(struct scsi_host_template *); |
| |
| /* |
| * Used as unload callback for hosts with old-style drivers. |
| * |
| * Status: OBSOLETE |
| */ |
| int (* release)(struct Scsi_Host *); |
| |
| /* |
| * 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, 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, int cmd, void __user *arg); |
| #endif |
| |
| /* |
| * 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 HBA has accepted the |
| * command. 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_cmnd *, |
| void (*done)(struct scsi_cmnd *)); |
| |
| /* |
| * 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_strategy_handler)(struct Scsi_Host *); |
| int (* eh_abort_handler)(struct scsi_cmnd *); |
| int (* eh_device_reset_handler)(struct scsi_cmnd *); |
| int (* eh_bus_reset_handler)(struct scsi_cmnd *); |
| int (* eh_host_reset_handler)(struct scsi_cmnd *); |
| |
| /* |
| * This is an optional routine to notify the host that the scsi |
| * timer just fired. The returns tell the timer routine what to |
| * do about this: |
| * |
| * EH_HANDLED: I fixed the error, please complete the command |
| * EH_RESET_TIMER: I need more time, reset the timer and |
| * begin counting again |
| * EH_NOT_HANDLED Begin normal error recovery |
| * |
| * Status: OPTIONAL |
| */ |
| enum scsi_eh_timer_return (* eh_timed_out)(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_adjust_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 *); |
| |
| /* |
| * 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. |
| * |
| */ |
| int (* change_queue_depth)(struct scsi_device *, int); |
| |
| /* |
| * fill in this function to allow the changing of tag types |
| * (this also allows the enabling/disabling of tag command |
| * queueing). An error should only be returned if something |
| * went wrong in the driver while trying to set the tag type. |
| * If the driver doesn't support the requested tag type, then |
| * it should set the closest type it does support without |
| * returning an error. Returns the actual tag type set. |
| */ |
| int (* change_queue_type)(struct scsi_device *, int); |
| |
| /* |
| * 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 []); |
| |
| /* |
| * 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 (*proc_info)(struct Scsi_Host *, char *, char **, off_t, int, int); |
| |
| /* |
| * Name of proc directory |
| */ |
| char *proc_name; |
| |
| /* |
| * Used to store the procfs directory if a driver implements the |
| * proc_info method. |
| */ |
| struct proc_dir_entry *proc_dir; |
| |
| /* |
| * 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 given host adapter 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; |
| |
| /* |
| * If the host adapter has limitations beside segment count |
| */ |
| unsigned short max_sectors; |
| |
| /* |
| * dma scatter gather segment boundary limit. a segment crossing this |
| * boundary will be split in two. |
| */ |
| unsigned long dma_boundary; |
| |
| /* |
| * 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; |
| |
| /* |
| * present contains counter indicating how many boards of this |
| * type were found when we did the scan. |
| */ |
| unsigned char present; |
| |
| /* |
| * true if this host adapter uses unchecked DMA onto an ISA bus. |
| */ |
| unsigned unchecked_isa_dma:1; |
| |
| /* |
| * true if this host adapter can make good use of clustering. |
| * I originally thought that if the tablesize was large that it |
| * was a waste of CPU cycles to prepare a cluster list, but |
| * it works out that the Buslogic is faster if you use a smaller |
| * number of segments (i.e. use clustering). I guess it is |
| * inefficient. |
| */ |
| unsigned use_clustering:1; |
| |
| /* |
| * 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; |
| |
| /* |
| * ordered write support |
| */ |
| unsigned ordered_flush:1; |
| unsigned ordered_tag: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 sysfs class properties for this host, NULL terminated. |
| */ |
| struct class_device_attribute **shost_attrs; |
| |
| /* |
| * Pointer to the SCSI device properties for this host, NULL terminated. |
| */ |
| struct device_attribute **sdev_attrs; |
| |
| /* |
| * List of hosts per template. |
| * |
| * This is only for use by scsi_module.c for legacy templates. |
| * For these access to it is synchronized implicitly by |
| * module_init/module_exit. |
| */ |
| struct list_head legacy_hosts; |
| }; |
| |
| /* |
| * 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 beeing 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 scsi_host_cmd_pool *cmd_pool; |
| spinlock_t free_list_lock; |
| struct list_head free_list; /* backup store of cmd structs */ |
| struct list_head starved_list; |
| |
| spinlock_t default_lock; |
| spinlock_t *host_lock; |
| |
| struct semaphore scan_mutex;/* serialize scanning activity */ |
| |
| struct list_head eh_cmd_q; |
| struct task_struct * ehandler; /* Error recovery thread. */ |
| struct semaphore * eh_action; /* Wait for specific actions on the |
| host. */ |
| unsigned int eh_active:1; /* Indicates the eh thread is awake and active if |
| this is true. */ |
| wait_queue_head_t host_wait; |
| struct scsi_host_template *hostt; |
| struct scsi_transport_template *transportt; |
| |
| /* |
| * The following two fields are protected with host_lock; |
| * however, eh routines can safely access during eh processing |
| * without acquiring the lock. |
| */ |
| unsigned int host_busy; /* commands actually active on low-level */ |
| unsigned int host_failed; /* commands that failed. */ |
| |
| unsigned short host_no; /* Used for IOCTL_GET_IDLUN, /proc/scsi et al. */ |
| int resetting; /* if set, it means that last_reset is a valid value */ |
| unsigned long last_reset; |
| |
| /* |
| * These three parameters can be used to allow for wide scsi, |
| * and for host adapters that support multiple busses |
| * The first two should be set to 1 more than the actual max id |
| * or lun (i.e. 8 for normal systems). |
| */ |
| unsigned int max_id; |
| unsigned int max_lun; |
| unsigned int max_channel; |
| |
| /* |
| * 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. |
| * For drivers that don't set this field, a value of 12 is |
| * assumed. I am leaving this as a number rather than a bit |
| * because you never know what subsequent SCSI standards might do |
| * (i.e. could there be a 20 byte or a 24-byte command a few years |
| * down the road?). |
| */ |
| unsigned char max_cmd_len; |
| |
| int this_id; |
| int can_queue; |
| short cmd_per_lun; |
| short unsigned int sg_tablesize; |
| short unsigned int max_sectors; |
| unsigned long dma_boundary; |
| /* |
| * Used to assign serial numbers to the cmds. |
| * Protected by the host lock. |
| */ |
| unsigned long cmd_serial_number, cmd_pid; |
| |
| unsigned unchecked_isa_dma:1; |
| unsigned use_clustering:1; |
| unsigned use_blk_tcq:1; |
| |
| /* |
| * 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; |
| |
| /* |
| * ordered write support |
| */ |
| unsigned ordered_flush:1; |
| unsigned ordered_tag:1; |
| |
| /* |
| * Optional work queue to be utilized by the transport |
| */ |
| char work_q_name[KOBJ_NAME_LEN]; |
| struct workqueue_struct *work_q; |
| |
| /* |
| * Host has rejected a command because it was busy. |
| */ |
| unsigned int host_blocked; |
| |
| /* |
| * Value host_blocked counts down from |
| */ |
| unsigned int max_host_blocked; |
| |
| /* 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; |
| struct class_device shost_classdev; |
| |
| /* |
| * List of hosts per template. |
| * |
| * This is only for use by scsi_module.c for legacy templates. |
| * For these access to it is synchronized implicitly by |
| * module_init/module_exit. |
| */ |
| struct list_head sht_legacy_list; |
| |
| /* |
| * Points to the transport data (if any) which is allocated |
| * separately |
| */ |
| void *shost_data; |
| |
| /* |
| * 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[0] /* Used for storage of host specific stuff */ |
| __attribute__ ((aligned (sizeof(unsigned long)))); |
| }; |
| |
| #define class_to_shost(d) \ |
| container_of(d, struct Scsi_Host, shost_classdev) |
| |
| #define shost_printk(prefix, shost, fmt, a...) \ |
| dev_printk(prefix, &(shost)->shost_gendev, fmt, ##a) |
| |
| |
| 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; |
| } |
| |
| 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(struct scsi_host_template *, int); |
| extern int __must_check scsi_add_host(struct Scsi_Host *, struct device *); |
| extern void scsi_scan_host(struct Scsi_Host *); |
| extern void scsi_scan_single_target(struct Scsi_Host *, unsigned int, |
| unsigned int); |
| extern void scsi_rescan_device(struct device *); |
| extern void scsi_remove_host(struct Scsi_Host *); |
| extern struct Scsi_Host *scsi_host_get(struct Scsi_Host *); |
| extern void scsi_host_put(struct Scsi_Host *t); |
| extern struct Scsi_Host *scsi_host_lookup(unsigned short); |
| extern const char *scsi_host_state_name(enum scsi_host_state); |
| |
| extern u64 scsi_calculate_bounce_limit(struct Scsi_Host *); |
| |
| static inline void scsi_assign_lock(struct Scsi_Host *shost, spinlock_t *lock) |
| { |
| shost->host_lock = lock; |
| } |
| |
| 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; |
| } |
| |
| extern void scsi_unblock_requests(struct Scsi_Host *); |
| extern void scsi_block_requests(struct Scsi_Host *); |
| |
| struct class_container; |
| /* |
| * These two functions are used to allocate and free a pseudo device |
| * which will connect to the host adapter itself rather than any |
| * physical device. You must deallocate when you are done with the |
| * thing. This physical pseudo-device isn't real and won't be available |
| * from any high-level drivers. |
| */ |
| extern void scsi_free_host_dev(struct scsi_device *); |
| extern struct scsi_device *scsi_get_host_dev(struct Scsi_Host *); |
| |
| /* legacy interfaces */ |
| extern struct Scsi_Host *scsi_register(struct scsi_host_template *, int); |
| extern void scsi_unregister(struct Scsi_Host *); |
| extern int scsi_host_set_state(struct Scsi_Host *, enum scsi_host_state); |
| |
| #endif /* _SCSI_SCSI_HOST_H */ |