When the remote device transitions to a not-ready state because of
an NCQ error condition, all outstanding requests to that device
are terminated and completed to libsas on the normal path.  The
device then waits for a READ LOG EXT command to issue on the task
management path.
Signed-off-by: NJeff Skirvin <jeffrey.d.skirvin@intel.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Now that we have upleveled device reassignment protection to the
isci_remote_device reference count we no longer need this level of
self-defense.
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Now that "stopping/stopped" are one in the same and signalled by a NULL device
pointer the rest of the device status infrastructure can be removed (->status
and ->state_lock).  The "not ready for i/o state" is replaced with a state
flag, and is evaluated under scic_lock so that we don't see transients from
taking the device reference to submitting the i/o.

This also fixes a potential leakage of can_queue slots in the rare case that
SAS_TASK_ABORTED is set at submission.
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

We have unsafe references to remote devices that are notified to
disappear at lldd_dev_gone.  In order to clean this up we need a single
canonical source for device lookups and stable references once a lookup
succeeds.  Towards that end guarantee that domain_device.lldd_dev is
NULL as soon as we start the process of stopping a device.  Any code
path that wants to safely lookup a remote device must do so through
task->dev->lldd_dev (isci_lookup_device()).

For in-flight references outside of scic_lock we need reference counting
to ensure that the device is not recycled before we are done with it.
Simplify device back references to just scic_sds_request.target_device
which is now the only permissible internal reference that is maintained
relative to the reference count.

There were two occasions where we wanted new i/o's to be treated as
SAS_TASK_UNDELIVERED but where the domain_dev->lldd_dev link is still
intact.  Introduce a 'gone' flag to prevent i/o while waiting for libsas
to take action on the port down event.

One 'core' leftover is that we currently call
scic_remote_device_destruct() from isci_remote_device_deconstruct()
which is called when the 'core' says the device is stopped.  It would be
more natural for the final put to trigger
isci_remote_device_deconstruct() but this implementation is deferred as
it requires other changes.
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

This cleans up several areas of the state machine mechanism:

 o Rename sci_base_state_machine_change_state to sci_change_state
 o Remove sci_base_state_machine_get_state function
 o Rename 'state_machine' struct member to 'sm' in client structs
 o Shorten the name of request states
 o Shorten state machine state names as follows:
        SCI_BASE_CONTROLLER_STATE_xxx to SCIC_xxx
        SCI_BASE_PHY_STATE_xxx to SCI_PHY_xxx
        SCIC_SDS_PHY_STARTING_SUBSTATE_xxx to SCI_PHY_SUB_xxx
        SCI_BASE_PORT_STATE_xxx to SCI_PORT_xxx and
        SCIC_SDS_PORT_READY_SUBSTATE_xxx to SCI_PORT_SUB_xxx
        SCI_BASE_REMOTE_DEVICE_STATE_xxx to SCI_DEV_xxx
        SCIC_SDS_STP_REMOTE_DEVICE_READY_SUBSTATE_xxx to SCI_STP_DEV_xxx
        SCIC_SDS_SMP_REMOTE_DEVICE_READY_SUBSTATE_xxx to SCI_SMP_DEV_xxx
        SCIC_SDS_REMOTE_NODE_CONTEXT_xxx_STATE to SCI_RNC_xxx
Signed-off-by: NEdmund Nadolski <edmund.nadolski@intel.com>
Signed-off-by: NDave Jiang <dave.jiang@intel.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

cross driver constants are spread out over multiple header files, consolidate
them into isci.h, and push some includes out to the source files that need
them.

TODO: remove SCI_MODE_SIZE infrastructure.
TODO: task.h is full of inlines that are too large
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

This is a requirement for 2.6.39's new libata eh.

Still some questions about lldd_dev_gone racing against dev->lldd_dev
lookups, but we are at least no more broken than mvsas in this regard.

We also short-circuit I_T_nexus_reset invocations from the device
discovery path (IDEV_EH similar to MVS_DEV_EH) to filter out the
resulting domain rediscoveries triggered by the reset.
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Signed-off-by: NDave Jiang <dave.jiang@intel.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Remove the now unused state_handler infrastructure for remote_devices.
Reported-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Implement all states in scic_sds_remote_device_frame() and delete
the state handler.
Reported-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Implement all states in scic_sds_remote_device_event() and delete
the state handler.
Reported-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

This is unused infrastructure.
Reported-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Implement all states in scic_sds_remote_device_suspend() and delete
the state handler.
Reported-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

This is unused infrastructure.
Reported-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Implement all states in scic_sds_remote_device_start_task() and delete
the state handler.
Reported-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

This is unused infrastructure.
Reported-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Implement all states in scic_sds_remote_device_complete_io() and delete
the state handler.
Reported-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Implement all states in scic_sds_remote_device_start_io() and delete the
state handler.
Reported-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Implement all states in scic_remote_device_reset_complete() and delete the
state handler.
Reported-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Implement all states in scic_remote_device_reset() and delete the state
handler.
Reported-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Implement all states in scic_remote_device_destruct() and delete the state
handler.
Reported-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

This is just unused infrastructure.
Reported-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Implement all states in scic_remote_device_stop() and delete the state
handlers.
Reported-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Implement all states in scic_remote_device_start() and delete the state
handler.
Reported-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

A function call to dereference a pointer is a tad much.
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

A substate is just a state, so uplevel the smp and stp device substates.
Three tricks at work here:

1/ scic_sds_remote_device_ready_state_enter: needs to know the the device type
   so it can immediately transition to a stp or smp ready substate.

2/ scic_sds_remote_device_ready_state_exit: needs to know the device type. In
   the ssp case the device is no longer ready, in the stp, and smp case we have
   simply exited to a ready "substate".

3/ scic_sds_remote_device_resume_complete_handler: The one location
   where we directly check the current state against
   SCI_BASE_REMOTE_DEVICE_STATE_READY needed to comprehend the possible ready
   substates.
Reported-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

The 'struct sci_base_object' was removed from the struct
scic_sds_remote_device.
Signed-off-by: NMaciej Patelczyk <maciej.patelczyk@intel.com>
[cleaned up sci_dev_to_idev]
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Removing not used / bit-rotten ATAPI code. This needs to go back
and debugged at a later date.
Signed-off-by: NDave Jiang <dave.jiang@intel.com>
[reflow against devel, delete dead sati headers]
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Longer to type than the open-coded equivalent.
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

The sas address can be retrieved from the domain device and then
converted to the always little-endian format in the remote node context.
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

This is step 1 of removing the contortions to:
1/ unparse expander phy data into a smp discover frame
2/ open-code-parse the smp discover fram into a domain_device.dev_type equivalent

libsas has already spent cycles determining the dev_type, so now that
scic_sds_remote_device is unified with isci_remote_device we can
directly reference dev_type.

This might also change multi-level expander detection as we previously only
looked at dev_type == EDGE_DEV and we did not consider the FANOUT_DEV case.
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Now that the core/lldd remote_device data structures are nominally unified
merge the corresponding sources into the top-level directory.  Also move the
remote_node_context infrastructure which has no analog at the lldd level.
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Make it explicit that isci_remote_device and scic_sds_remote_device are
one in the same object.
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

A domain_device can always reference back to ->lldd_ha unlike local lldd
structures.  Fix up cases where the driver uses local objects to look up the
isci_host.  This also changes the calling conventions of some routines to
expect a valid isci_host parameter rather than re-lookup the pointer on entry.

Incidentally cleans up some macros that are longer to type than the open-coded
equivalent:
  isci_host_from_sas_ha
  isci_dev_from_domain_dev
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Require a valid isci_host in support of the general cleanup to not
re-lookup the host via potentially fragile methods when more robust
methods are available.  Also cleans up some more casting that should be
using container_of() to up-cast a base structure in a more type-safe
manner.
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Until we synchronize against device removal this limits the damage of
use after free bugs to the driver's own objects.  Unless we implement
reference counting we need to ensure at least a subset of a remote
device is valid at all times.  We follow the lead of other libsas
drivers that also preallocate devices.

This also enforces maximum remote device accounting at the lldd layer,
but the core may still run out of RNC's before we hit this limit.
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Replace the device completion infrastructure with the controller wide
event queue.  There was a potential for the stop and ready notifications
to corrupt each other, now that cannot happen.

The stop pending flag cannot be used until devices are statically
allocated.  We temporarily need to maintain a completion to handle
waiting for an object that has disappeared, but we can at least stop
scribbling on freed memory.

A future change will also get rid of the "stopping" state as it should
not be exposed to the rest of the driver.
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

The midlayer is already throttling i/o in the places where host_quiesce
was trying to prevent further i/o to the device.  It's also problematic
in that it holds a lock over GFP_KERNEL allocations.
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

It belies the fact that isci_remote_device and scic_sds_remote_device
are one in same object with the same lifetime rules.
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Removed all callbacks in the deprecated.c. Core will call the appropriate
functions directly.
Signed-off-by: NDave Jiang <dave.jiang@intel.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>