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#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>

struct request_queue;

struct block_device;

struct completion;

struct module;

struct scsi_cmnd;

struct scsi_device;

struct scsi_target;

struct Scsi_Host;

struct scsi_host_cmd_pool;

struct scsi_transport_template;

struct blk_queue_tags;

/*

 * 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 MODE_UNKNOWN 0x00

#define MODE_INITIATOR 0x01

#define MODE_TARGET 0x02

#define DISABLE_CLUSTERING 0

#define ENABLE_CLUSTERING 1

#define DISABLE_SG_CHAINING 0

#define ENABLE_SG_CHAINING 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         * Status:  OBSOLETE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         * Status: OBSOLETE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 *));

        /*

         * The transfer functions are used to queue a scsi command to

         * the LLD. When the driver is finished processing the command

         * the done callback is invoked.

         *

         * This is called to inform the LLD to transfer

         * cmd->request_bufflen bytes. The cmd->use_sg speciefies the

         * number of scatterlist entried in the command and

         * cmd->request_buffer contains the scatterlist.

         *

         * return values: see queuecommand

         *

         * If the LLD accepts the cmd, it should set the result to an

         * appropriate value when completed before calling the done function.

         *

         * STATUS: REQUIRED FOR TARGET DRIVERS

         */

        /* TODO: rename */

        int (* transfer_response)(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_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 *);

        /*

         * 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 *);

        /*

         * 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.

         */

        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.

         *

         */

        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);

        /*

         * 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:

         * 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 *);

        /*

         * Name of proc directory

         */

        const 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;

        /*

         * This specifies the mode that a LLD supports.

         */

        unsigned supported_mode:2;

        /*

         * 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_tag:1;

        /*

         * true if the low-level driver can support sg chaining. this

         * will be removed eventually when all the drivers are

         * converted to support sg chaining.

         *

         * Status: OBSOLETE

         */

        unsigned use_sg_chaining: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 mutex            scan_mutex;/* serialize scanning activity */

        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;

        struct scsi_host_template *hostt;

        struct scsi_transport_template *transportt;

        /*

         * area to keep a shared tag map (if needed, will be

         * NULL if not)

         */

        struct blk_queue_tag    *bqt;

        /*

         * 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 int host_eh_scheduled;    /* EH scheduled without command */

        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;

        unsigned active_mode:2;

        unsigned unchecked_isa_dma:1;

        unsigned use_clustering:1;

        unsigned use_blk_tcq:1;

        unsigned use_sg_chaining: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_tag:1;

        /* task mgmt function in progress */

        unsigned tmf_in_progress:1;

        /* Asynchronous scan in progress */

        unsigned async_scan: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;

        /*

         * q used for scsi_tgt msgs, async events or any other requests that

         * need to be processed in userspace

         */

        struct request_queue *uspace_req_q;

        /* 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)

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(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_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 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;

extern struct request_queue *__scsi_alloc_queue(struct Scsi_Host *shost,

                                                void (*) (struct request_queue *));

/*

 * 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 */