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>

A tag is a 16 bit number where the upper four bits is a sequence number
and the remainder is the task context index (tci).  Sanitize the macro
names and shave 256-bytes out of scic_sds_controller by reducing the size of
io_request_sequence.

scic_sds_io_tag_construct --> ISCI_TAG
scic_sds_io_tag_get_sequence --> ISCI_TAG_SEQ
scic_sds_io_tag_get_index() --> ISCI_TAG_TCI
scic_sds_io_sequence_increment() [delete / open code]
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

In the case where the hard reset process fails, each link in
the port is put through a link reset sequence.
Signed-off-by: NJeff Skirvin <jeffrey.d.skirvin@intel.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

When resetting a sata device in the domain we have seen occasions where
libsas prematurely marks a device gone in the time it takes for the
device to re-establish the link.  This plays badly with software raid
arrays.  Other libsas drivers have non-uniform delays in their reset
handlers to try to cover this condition, but not sufficient to close the
hole.  Given that a sata device can take many seconds to recover we
filter bcns and poll for the device reattach state before notifying
libsas that the port needs the domain to be rediscovered.  Once this has
been proven out at the lldd level we can think about uplevelling this
feature to a common implementation in libsas.
Signed-off-by: NJeff Skirvin <jeffrey.d.skirvin@intel.com>
[ use kzalloc instead of kmem_cache ]
Signed-off-by: NDave Jiang <dave.jiang@intel.com>
[ use eventq and time macros ]
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Additional state machine cleanups:

 o Remove static functions sci_state_machine_exit_state() and
   sci_state_machine_enter_state()
 o Combines sci_base_state_machine_construct() and
   sci_base_state_machine_start() into a single function,
   sci_init_sm()
 o Remove sci_base_state_machine_stop() which is unused.
 o Kill state_machine.[ch]
Signed-off-by: NEdmund Nadolski <edmund.nadolski@intel.com>
[fixed too large to inline functions]
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>

Delete code which is no longer used.
Signed-off-by: NEdmund Nadolski <edmund.nadolski@intel.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Rather than preallocating a list of timers and doling them out at runtime,
embed a struct timerlist in each object that needs one.  A struct sci_timer
interface is introduced to manage the timer cancellation semantics which
currently need to guarantee the timer is cancelled while holding
spin_lock(ihost->scic_lock).  Since the timeout functions also need to acquire
the lock it currently prevents the driver from using del_timer_sync() for
runtime cancellations.

del_timer_sync() is used however before the objects go out of scope.
Signed-off-by: NEdmund Nadolski <edmund.nadolski@intel.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Now that any given object type only has one state_machine we can use
container_of() to get back to the given state machine owner.
Reported-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Unify the handlers and kill the state handler infrastructure.
Reported-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Unify the handlers and kill the state handler implementations.
Reported-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NPiotr Sawicki <piotr.sawicki@intel.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Unused infrastructure.
Reported-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NPiotr Sawicki <piotr.sawicki@intel.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Unify the implementations and remove the state handlers.
Reported-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NPiotr Sawicki <piotr.sawicki@intel.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

The handler was never used.
Signed-off-by: NPiotr Sawicki <piotr.sawicki@intel.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Implement the stop handlers directly in scic_sds_port_stop()
Reported-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NPiotr Sawicki <piotr.sawicki@intel.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

remove the handler from the port state handler table and implement the
logic directly in scic_sds_port_start().
Signed-off-by: NPiotr Sawicki <piotr.sawicki@intel.com>
[remove a level of indirection]
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

This conversion was complicated by the fact that the ready state exit routine
took unconditional action beyond just stopping the substate machine (like in
previous conversions).  In order to ensure identical behaviour every state
transition needs to be instrumented to catch ready-->!ready transitions and
execute scic_sds_port_invalidate_dummy_remote_node()
Reported-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NPiotr Sawicki <piotr.sawicki@intel.com>
[fix ready state exit handling]
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Name the table fields for consistancy and clarity.
Signed-off-by: NPiotr Sawicki <piotr.sawicki@intel.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

While cleaning up the driver it is very tempting to convert scic_sds_get_*
macros to their open coded equivalent.  They are all just pointer dereferences
*except* scic_sds_phy_get_port() which returns NULL if the phy is assigned to
the dummy port.  Clarify this by renaming it to phy_get_non_dummy_port().
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

* Move port configuration agent implementation
* Merge core/scic_sds_port.[ch] into port.[ch]
Reported-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Merge core/scic_sds_phy.[ch] into phy.[ch]
Reported-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

* Consolidate tiny header files
* Move files out of core/ (drop core/scic_sds_ prefix)
* Merge core/scic_sds_request.[ch] into request.[ch]
* Cleanup request.c namespace (clean forward declarations and global
  namespace pollution)
Reported-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Now that the data structures are unified unify the implementation in
host.[ch] and cleanup namespace pollution.
Reported-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Make scic_sds_port a member of isci_port and merge their lifetimes which
means removing the port table from scic_sds_controller in favor of the
one at the isci_host level.  Merge ihost->sas_ports into ihost->ports.
_
Reported-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Make scic_sds_phy a member of isci_phy and merge their lifetimes which
means removing the phy table from scic_sds_controller in favor of the
one at that isci_host level.
Reported-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

This function is just overkill and its usage is inconsistent. Replace
with inlined code.
Signed-off-by: NEdmund Nadolski <edmund.nadolski@intel.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Make it explicit that isci_host and scic_sds_controller are one in the same
object.
Signed-off-by: NArtur Wojcik <artur.wojcik@intel.com>
[removed ->ihost back pointer]
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Moved the actual data structure that's read from the phy register to phy
header.  Removed the parsing of identify address frame protocol bits as
that seemed not necessary and we can use existing information.
Signed-off-by: NDave Jiang <dave.jiang@intel.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

We need to remove the extra copies of identify address frame that's
being kept around. We only need the one copy that libsas is using.
Signed-off-by: NDave Jiang <dave.jiang@intel.com>
[further cleanups]
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

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

Converting of sata_fis_reg_d2h to dev_to_host_fis
Converting of sata_fis_reg_h2d to host_to_dev_fis
Signed-off-by: NDave Jiang <dave.jiang@intel.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

The 'struct sci_base_object' was removed from the struct
scic_sds_port and was replaced by a pointer to
struct isci_port.
Signed-off-by: NMaciej Patelczyk <maciej.patelczyk@intel.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

The 'struct sci_base_object' was removed from the struct
scic_sds_phy and was replaced by a pointer to
struct isci_phy.
Signed-off-by: NMaciej Patelczyk <maciej.patelczyk@intel.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

The 'struct sci_base_object' was removed from the struct
scic_sds_controller and was replaced by a pointer to
struct isci_host.
Signed-off-by: NMaciej Patelczyk <maciej.patelczyk@intel.com>
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>

Removes unnecessary usage of BUG_ON macro, excluding core directory.
In some cases macro is unnecesary, check is done in caller function.
In other cases macro is replaced by if construction with
appropriate warning.
Signed-off-by: NMaciej Patelczyk <maciej.patelczyk@intel.com>
[changed some survivable bug conditions to WARN_ONCE]
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>

* mark needlessly global routines static
* delete unused functions
* move kernel-doc blocks from header files to source
* reorder some functions to delete declarations
* more default handler cleanups phy
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Removed isci_event_* calls and call those functions directly.
Reported-by: NChristoph Hellwig <hch@infradead.org>
Signed-off-by: NDave Jiang <dave.jiang@intel.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

The remote_device_lock is currently used to protect a controller global
resource (RNCs), but the remote_device_lock is per-port.
Signed-off-by: NDan Williams <dan.j.williams@intel.com>