Hardware allows both an outstanding number commands and a timeout value
(whichever occurs first) as a gate to the next interrupt generation.  This
scheme at completion time looks at the remaining number of outstanding tasks
and sets the timeout to maximize small transaction operation.  If transactions
are large (take more than a few 10s of microseconds to complete) then
performance is not interrupt processing bound, so the small timeouts this
scheme generates are overridden by the time it takes for a completion to
arrive.
Tested-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

Perform checking per-pci device (even though all systems will only have
1 pci device in this generation), and delete support for silicon that
does not report a proper revision (i.e. A0).
Reported-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

Does not need its own file.
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

Most of these simple dereference macros are longer than their open coded
equivalent.  Deleting enum sci_controller_mode is thrown in for good
measure.
Reported-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

The distinction between scic_sds_ scic_ and sci_ are no longer relevant
so just unify the prefixes on sci_.  The distinction between isci_ and
sci_ is historically significant, and useful for comparing the old
'core' to the current Linux driver. 'sci_' represents the former core as
well as the routines that are closer to the hardware and protocol than
their 'isci_' brethren. sci == sas controller interface.

Also unwind the 'sds1' out of the parameter structs.
Reported-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

Remove the distinction between these two implementations and unify on
isci_host (local instances named ihost).  Hmmm, we had two
'oem_parameters' instances, one was unused... nice.
Reported-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

Remove the distinction between these two implementations and unify on
isci_remote_device (local instances named idev).
Reported-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

Remove the distinction between these two implementations and unify on
isci_port (local instances named iport).  The duplicate '->owning_port' and
'->isci_port' in both isci_phy and isci_remote_device will be fixed in a later
patch... this is just the straightforward rename/unification.
Reported-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

They are one in the same object so remove the distinction.  The near
duplicate fields (owning_port, and isci_port) will be cleaned up
after the scic_sds_port isci_port unification.
Reported-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

They are one in the same object so remove the distinction.  The near
duplicate fields (owning_controller, and isci_host) will be cleaned up
after the scic_sds_contoller isci_host unification.
Reported-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

the dma_pool interface is optimized for object_size << page_size which
is not the case with isci_request objects and the dma_pool routines show
up in the top of the profile.

The old io_request_table which tracked whether tci slots were in-flight
or not is replaced with an IREQ_ACTIVE flag per request.
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

The tci_pool tracks our outstanding command slots which are also the 'index'
portion of our tags.  Grabbing the tag early in ->lldd_execute_task let's us
drop the isci_host_can_queue() and ->was_tag_assigned_by_user infrastructure.
->was_tag_assigned_by_user required the task context to be duplicated in
request-local buffer.  With the tci established early we can build the
task_context directly into its final location and skip a memcpy.

With the task context buffer at a known address at request construction we
have the opportunity/obligation to also fix sgl handling.  This rework feels
like it belongs in another patch but the sgl handling and task_context are too
intertwined.
1/ fix the 'ab' pair embedded in the task context to point to the 'cd' pair in
   the task context (previously we were prematurely linking to the staging
   buffer).
2/ fix the broken iteration of pio sgls that assumes all sgls are relative to
   the request, and does a dangerous looking reverse lookup of physical
   address to virtual address.
Signed-off-by: Dan 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: Dan Williams <dan.j.williams@intel.com>

Every single i/o or event completion incurs a test and branch to see if
the cycle bit changed.  For power-of-2 queue sizes the cycle bit can be
read directly from the rollover of the queue pointer.

Likely premature optimization, but the hidden if() and hidden
assignments / side-effects in the macros were already asking to be
cleaned up.
Signed-off-by: Dan 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: Dan Williams <dan.j.williams@intel.com>

The circ_buf macros are ~6% faster, as measured by perf, because they take
advantage of power-of-two math assumptions i.e. no test and branch for
rollover. Their semantics are clearer than the hidden side effects in pool.h
(like sci_pool_get() which hides an assignment).
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

The old 'core' had aspirations of running in severely memory constrained
environments like bios option-rom, it's not needed for Linux and gets in
the way of other cleanups (like unifying/reducing the number of structure
members in scic_sds_controller/isci_host).

This also fixes a theoretical bug in that the driver would blindly override
the silicon advertised limits for number of ports, task contexts, and remote
node contexts.
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

C0 silicon updates the pci revision id and requires new AFE parameters
for phy signal integrity.  Support for previous silicon revisions is
deprecated (it's also broken for the theoretical case of multiple
controllers at different silicon revisions, all the more reason to get
it removed as soon as possible)
Signed-off-by: Adam Gruchala <adam.gruchala@intel.com>
[fixed up deprecated silicon support]
Signed-off-by: Dan 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: Edmund Nadolski <edmund.nadolski@intel.com>
[fixed too large to inline functions]
Signed-off-by: Dan 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: Edmund Nadolski <edmund.nadolski@intel.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

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

Signed-off-by: Edmund Nadolski <edmund.nadolski@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

Signed-off-by: Edmund Nadolski <edmund.nadolski@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

Signed-off-by: Edmund Nadolski <edmund.nadolski@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

Signed-off-by: Edmund Nadolski <edmund.nadolski@intel.com>
[squashed collateral cleanups]
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

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

unify core/sci_base_state.h and core/sci_base_state_machine.[ch] into
state_machine.[ch]
Reported-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

Reported-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dan 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: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dan 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: Dan Williams <dan.j.williams@intel.com>

Make scic_sds_request a proper member of isci_request.  Also let's us
get rid of the dma pool object size tracking since we now know that all
requests are sizeof(isci_request).  While cleaning up the construct
routine incidentally replaced SCI_FIELD_OFFSET with offsetof.
Reported-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dan 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: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dan 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: Artur Wojcik <artur.wojcik@intel.com>
[removed ->ihost back pointer]
Signed-off-by: Dan 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: Dan 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: Dan Williams <dan.j.williams@intel.com>

Remove the insane infrastructure for preallocating coheren DMA regions,
and just allocate the memory where needed.  This also gets rid of the
aligment adjustments given that Documentation/DMA-API-HOWTO.txt sais:

  "The cpu return address and the DMA bus master address are both
   guaranteed to be aligned to the smallest PAGE_SIZE order which
   is greater than or equal to the requested size.  This invariant
   exists (for example) to guarantee that if you allocate a chunk
   which is smaller than or equal to 64 kilobytes, the extent of the
   buffer you receive will not cross a 64K boundary."
Signed-off-by: Christoph Hellwig <hch@lst.de>
[djbw: moved allocation from start to init, re-add memset]
Signed-off-by: Dan 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: Dan Williams <dan.j.williams@intel.com>

We need to scan the OROM for signature and grab the OEM parameters. We
also need to do the same for EFI. If all fails then we resort to user
binary blob, and if that fails then we go to the defaults.

Share the format with the create_fw utility so that all possible sources
of the parameters are in-sync.
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

Changes to move management of the reqs_in_process entry for the request here.
Made changes to note when the task is already in the abort path and
cannot be completed through callbacks.
Signed-off-by: Jeff Skirvin <jeffrey.d.skirvin@intel.com>
Signed-off-by: Jacek Danecki <Jacek.Danecki@intel.com>
Signed-off-by: Dan 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: Dan Williams <dan.j.williams@intel.com>