[SCSI] kill scsi_assign_lock

   scsi_add_device - creates new scsi device (lu) instance

   scsi_add_host - perform sysfs registration and set up transport class

   scsi_adjust_queue_depth - change the queue depth on a SCSI device

   scsi_assign_lock - replace default host_lock with given lock

   scsi_bios_ptable - return copy of block device's partition table

   scsi_block_requests - prevent further commands being queued to given host

   scsi_deactivate_tcq - turn off tag command queueing

                             int tags)

/**

 * scsi_assign_lock - replace default host_lock with given lock

 * @shost: a pointer to a scsi host instance

 * @lock: pointer to lock to replace host_lock for this host

 *

 *      Returns nothing

 *

 *      Might block: no

 *

 *      Defined in: include/scsi/scsi_host.h .

 **/

void scsi_assign_lock(struct Scsi_Host *shost, spinlock_t *lock)

/**

 * scsi_bios_ptable - return copy of block device's partition table

 * @dev:        pointer to block device

Each struct Scsi_Host instance has a spin_lock called struct 

Scsi_Host::default_lock which is initialized in scsi_host_alloc() [found in 

hosts.c]. Within the same function the struct Scsi_Host::host_lock pointer

is initialized to point at default_lock with the scsi_assign_lock() function.

Thereafter lock and unlock operations performed by the mid level use the

struct Scsi_Host::host_lock pointer.

LLDs can override the use of struct Scsi_Host::default_lock by

using scsi_assign_lock(). The earliest opportunity to do this would

be in the detect() function after it has invoked scsi_register(). It

could be replaced by a coarser grain lock (e.g. per driver) or a

lock of equal granularity (i.e. per host). Using finer grain locks 

(e.g. per SCSI device) may be possible by juggling locks in

queuecommand().

is initialized to point at default_lock.  Thereafter lock and unlock

operations performed by the mid level use the struct Scsi_Host::host_lock

pointer.  Previously drivers could override the host_lock pointer but

this is not allowed anymore.

Autosense

=========

	if (!shost)

		return NULL;

	spin_lock_init(&shost->default_lock);

	scsi_assign_lock(shost, &shost->default_lock);

	shost->host_lock = &shost->default_lock;

	spin_lock_init(shost->host_lock);

	shost->shost_state = SHOST_CREATED;

	INIT_LIST_HEAD(&shost->__devices);

	INIT_LIST_HEAD(&shost->__targets);

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;