Commit Graph

59 Commits

Author SHA1 Message Date
Dan Williams ffe191c92f isci: unify isci_port and scic_sds_port
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>
2011-07-03 04:04:52 -07:00
Dan Williams 852809559e isci: unify isci_phy and scic_sds_phy
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>
2011-07-03 04:04:52 -07:00
Dan Williams 5076a1a97e isci: unify isci_request and scic_sds_request
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>
2011-07-03 04:04:52 -07:00
Dan Williams db05625098 isci: preallocate requests
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>
2011-07-03 04:04:51 -07:00
Dan Williams 312e0c2455 isci: unify can_queue tracking on the tci_pool, uplevel tag assignment
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>
2011-07-03 04:04:51 -07:00
Dan Williams f208826751 isci: kill isci_remote_device_change_state()
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: Dan Williams <dan.j.williams@intel.com>
2011-07-03 04:04:51 -07:00
Dan Williams 209fae14fa isci: atomic device lookup and reference counting
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: Dan Williams <dan.j.williams@intel.com>
2011-07-03 04:04:51 -07:00
Dan Williams 994a9303d3 isci: cleanup/optimize queue increment macros
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>
2011-07-03 04:04:51 -07:00
Dan Williams dd047c8e2b isci: cleanup tag macros
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>
2011-07-03 04:04:51 -07:00
Dan Williams ac668c6970 isci: cleanup/optimize pool implementation
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>
2011-07-03 04:04:51 -07:00
Dan Williams 7c78da3175 isci: remove 'min memory' infrastructure
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>
2011-07-03 04:04:50 -07:00
Adam Gruchala dbb0743a58 isci: Added support for C0 to SCU Driver
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>
2011-07-03 04:04:50 -07:00
Edmund Nadolski 12ef65444d isci: additional state machine cleanup
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>
2011-07-03 04:04:50 -07:00
Edmund Nadolski e301370ac5 isci: state machine cleanup
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>
2011-07-03 04:04:50 -07:00
Edmund Nadolski 8db02da528 isci: remove isci_timer interface
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>
2011-07-03 04:04:50 -07:00
Edmund Nadolski bb3dbdf6c8 isci: convert phy_startup_timer to sci_timer
Signed-off-by: Edmund Nadolski <edmund.nadolski@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2011-07-03 04:04:49 -07:00
Edmund Nadolski 6cb5853d3e isci: convert scic_timeout_timer to sci_timer
Signed-off-by: Edmund Nadolski <edmund.nadolski@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2011-07-03 04:04:49 -07:00
Edmund Nadolski 0473661a12 isci: convert power control timer to sci_timer
Signed-off-by: Edmund Nadolski <edmund.nadolski@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2011-07-03 04:04:49 -07:00
Edmund Nadolski a628d47857 isci: convert phy sata_timeout_timer to sci_timer
Convert the sata_timeout_timer in the scic_sds_phy struct to
use a struct sci_timer

Signed-off-by: Edmund Nadolski <edmund.nadolski@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2011-07-03 04:04:49 -07:00
Edmund Nadolski ac0eeb4f77 isci: convert port config agent timer to sci_timer
Signed-off-by: Edmund Nadolski <edmund.nadolski@intel.com>
[squashed collateral cleanups]
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2011-07-03 04:04:49 -07:00
Edmund Nadolski 5553ba2be0 isci: replace isci_timer list with proper embedded timers
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>
2011-07-03 04:04:49 -07:00
Dan Williams 9269e0e898 isci: add some type safety to the state machine interface
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: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2011-07-03 04:04:49 -07:00
Piotr Sawicki 8bc80d3030 isci: unify port stop handlers
Implement the stop handlers directly in scic_sds_port_stop()

Reported-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Piotr Sawicki <piotr.sawicki@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2011-07-03 04:04:49 -07:00
Piotr Sawicki d76f71d988 isci: remove port start handler
remove the handler from the port state handler table and implement the
logic directly in scic_sds_port_start().

Signed-off-by: Piotr Sawicki <piotr.sawicki@intel.com>
[remove a level of indirection]
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2011-07-03 04:04:49 -07:00
Dan Williams 4f20ef4f57 isci: clarify phy to port lookups
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: Dan Williams <dan.j.williams@intel.com>
2011-07-03 04:04:48 -07:00
Adam Gruchala 4a33c525f0 isci: merge phy substates
Merged states and substates into one state machine, as we always
unconditionally transitioned to the substate machine it was straightforward to
enter that substate from the starting state.

Reported-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Adam Gruchala <adam.gruchala@intel.com>
[fixed construction, starting_state_enter, and starting check]
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2011-07-03 04:04:48 -07:00
Dan Williams e2f8db509f isci: uplevel port infrastructure
* 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>
2011-07-03 04:04:47 -07:00
Dan Williams f1f52e7593 isci: uplevel request infrastructure
* 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>
2011-07-03 04:04:47 -07:00
Dan Williams 63a3a15fb0 isci: uplevel register hardware data structures and unsolicited frame handling
Reported-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2011-07-03 04:04:47 -07:00
Dan Williams cc9203bf38 isci: move core/controller to host
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>
2011-07-03 04:04:47 -07:00
Dan Williams ce2b3261b6 isci: unify constants
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>
2011-07-03 04:04:47 -07:00
Dan Williams 67ea838d17 isci: unify request data structures
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>
2011-07-03 04:04:47 -07:00
Dan Williams b7645818cf isci: make command/response iu explicit request object members
Final elimination of the anonymous data at the end of the request
structure.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2011-07-03 04:04:47 -07:00
Dan Williams e531381e2f isci: unify port data structures
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>
2011-07-03 04:04:47 -07:00
Artur Wojcik cc3dbd0a91 isci: unify isci_host data structures
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>
2011-07-03 04:04:46 -07:00
Maciej Patelczyk d3757c3aeb isci: Removed sci_base_object from scic_sds_controller.
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: Maciej Patelczyk <maciej.patelczyk@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2011-07-03 04:00:38 -07:00
Dan Williams 88f3b62ac1 isci: move remote_device handling out of the core
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>
2011-07-03 04:00:38 -07:00
Dan Williams 57f20f4ed6 isci: unify remote_device data structures
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>
2011-07-03 04:00:38 -07:00
Dan Williams 31e824ed0d isci: rely on irq core for intx multiplexing, and silence screaming intx
Remove the extra logic to poll each controller for interrupts, that's
the core's job for shared interrupts.

While testing noticed that a number of interrupts fire while waiting for
the completion tasklet to run, so added an irq-ack.

Reported-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2011-07-03 04:00:37 -07:00
Christoph Hellwig bc5c96748a isci: simplify dma coherent allocation
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>
2011-07-03 04:00:37 -07:00
Christoph Hellwig ca841f0e86 isci: remove base_controller abstraction
Merge struct sci_base_controller into scic_sds_controller, and also factor
the two types of state machine handlers into one function.  While we're at
it also remove lots of duplicate incorrect kerneldoc comments for the state
machine handlers.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2011-07-03 04:00:37 -07:00
Dan Williams 4393aa4e6b isci: fix fragile/conditional isci_host lookups
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>
2011-07-03 04:00:36 -07:00
Dave Jiang b5f18a201e isci: exposing user parameters via module params
Exposing the user config parameters through the kernel module parameters.
The kernel module params will have the default values set and we will no
longer pulling the default values for user params from the core.

Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2011-07-03 03:58:14 -07:00
Dan Williams 4711ba10b1 isci: fix oem parameter initialization and mode detection
1/ Since commit 858d4aa7 "isci: Move firmware loading to per PCI device" we have
   been silently falling back to built-in defaults for the parameter settings by
   skipping the call to scic_oem_parameters_set().

2/ The afe parameters from the firmware were not being honored

3/ The latest oem parameter definition flips the mode_type values which are
   now 0: for APC 1: for MPC.  For APC we need to make sure all the phys
   default to the same address otherwise strict_wide_ports will cause duplicate
   domains.

4/ Fix up the driver announcement to indicate the source of the
   parameters.

5/ Fix up the sas addresses to be unique per controller (in the fallback case)

Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2011-07-03 03:55:31 -07:00
Dan Williams d044af17aa isci: Add support for probing OROM for OEM params
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>
2011-07-03 03:55:30 -07:00
Jeff Skirvin ec6c9638b0 isci: Any reset indicated on an I/O completion escalates it to the error path.
If there is a pending device reset, the I/O is used to accomplish the reset by setting the
RESET bit in the task status, and then putting the task into the error handler
path using sas abort task.

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>
2011-07-03 03:55:29 -07:00
Jeff Skirvin 11b00c194c isci: Changes in isci_host_completion_routine
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>
2011-07-03 03:55:29 -07:00
Dan Williams d9c37390c4 isci: preallocate remote devices
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>
2011-07-03 03:55:29 -07:00
Dan Williams 6ad31fec30 isci: replace isci_remote_device completion with event queue
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: Dan Williams <dan.j.williams@intel.com>
2011-07-03 03:55:29 -07:00
Dan Williams b329aff107 isci: kill isci_host list in favor of an array
isci_host_by_id() should have been a clue that an array would have been
a simpler approach.

Reported-by: James Bottomley <James.Bottomley@suse.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2011-07-03 03:55:29 -07:00