Kill the local smp response buffer.

Besides being unnecessary, it is too small (currently truncates
responses to 60 bytes).  The mid-layer will have already allocated a
sufficiently sized buffer, just kmap and copy into it directly.

Cc: <stable@kernel.org>
Reported-by: Derick Marks <derick.w.marks@intel.com>
Tested-by: Derick Marks <derick.w.marks@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.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>

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>

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>

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