In the case where submitted I/Os fail with the status code
SCI_FAILURE_REMOTE_DEVICE_RESET_REQUIRED, the execute function now waits
until scic_lock is cleared before calling the helper function
"isci_request_signal_device_reset" which sets the flag for the pending
reset condition on the I/O.
Signed-off-by: Jeff Skirvin <jeffrey.d.skirvin@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

A domain_device has the same lifetime as its related scsi_target.  The
scsi_target is reference counted based on outstanding commands,
therefore it is safe to assume that if we have a valid sas_task that the
->dev pointer is also valid.

The asd_sas_port of a domain_device has the same lifetime as the driver
so it can also never be NULL as long as the sas_task is valid and the
driver is loaded.

This also cleans up isci_task_complete_for_upper_layer(), renames it to
isci_task_refuse() and notices that the isci_completion_selection
parameter was set to isci_perform_normal_io_completion by all callers.
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

Allow each controller to be identified via sysfs.

# cat /sys/class/scsi_host/host13/isci_id
1
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

Make sure all pending I/O including any in the libsas error handler
process is cleaned-up.
Signed-off-by: Jeff Skirvin <jeffrey.d.skirvin@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

In the case of I/O requests being failed because of a required device
reset condition, set the response and status to indicate an I/O failure.
Signed-off-by: Jeff Skirvin <jeffrey.d.skirvin@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

Since libsas takes the domain device sata_dev.ap->lock before submitting
a task, error completions in the submit path for SATA devices must
unlock/relock when completing the sas_task back to libsas.
Signed-off-by: Jeff Skirvin <jeffrey.d.skirvin@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

The request may be in the "aborted" or the "completed" state when
performing a task management operation on it.
Signed-off-by: Jeff Skirvin <jeffrey.d.skirvin@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

In the case where a SAS or SATA LUN reset TMF is built a NULL pointer
dereference occurred because of the (unused) callback data pointer.
Signed-off-by: Jeff Skirvin <jeffrey.d.skirvin@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Jacek Danecki <Jacek.Danecki@intel.com>

Added a request "dead" state for use when a termination wait times-out.

isci_terminate_pending_requests now detaches the device's pending list
and terminates each entry on the detached list.
Signed-off-by: Jeff Skirvin <jeffrey.d.skirvin@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

Since the request structure contains a pointer to the completion to be
used if the request is being aborted or terminated, there is no reason
to pass the completion as a pointer to isci_terminate_request_core().
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>

Made sure the device ready check accounts for all states.
Moved the aborted task check into the loop of pulling task requests
off of the submitted list.
Signed-off-by: Jeff Skirvin <jeffrey.d.skirvin@intel.com>
Signed-off-by: Jacek Danecki <Jacek.Danecki@intel.com>
[remove host and device starting state checks]
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

The pointer to the core representation of a request is marked NULL at
completion, but we need to save the i/o tag for task management.
Signed-off-by: Jeff Skirvin <jeffrey.d.skirvin@intel.com>
Signed-off-by: Jacek Danecki <Jacek.Danecki@intel.com>
[revise changelog]
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

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>

Corrected use of the request state_lock in the completion callback.

In the case where an abort (or reset) thread is trying to terminate an
I/O request, it sets the request state to "aborting" (or "terminating")
if the state is still "starting".  One of the bugs was to never set the
state to "completed".  Another was to not correctly recognize the
situation where the I/O had completed but the sas_task was still pending
callback to task_done - this was typically a problem in the LUN and
device reset cases.

It is now possible that we leave isci_task_abort_task() with
request->io_request_completion pointing to localy allocated
aborted_io_completion struct. It may result in a system crash.
Signed-off-by: Jeff Skirvin <jeffrey.d.skirvin@intel.com>
Signed-off-by: Maciej Trela <Maciej.Trela@intel.com>
Signed-off-by: Jacek Danecki <Jacek.Danecki@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>

In the condition where outstanding I/Os are being cleaned from the device
requests in process list, the cleanup function needs to check that the
request is actually a sas-task and not a task management function.
Signed-off-by: Jeff Skirvin <jeffrey.d.skirvin@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

Reported-by: James Bottomley <James.Bottomley@suse.de>
Signed-off-by: Dan 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: 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>

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>

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: Dan 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: Dan Williams <dan.j.williams@intel.com>

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>

Now that phys_to_virt() and virt_to_phys() have been removed we are no
longer violating the dma mapping (or kmap apis).
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

Ross says:
 "The memory allocation for these requests doesn’t take into account the
  additional memory needed when the code in
  scic_sds_s[mst]p_request_assign_buffers() shifts the struct
  scu_task_context so that it is cache line aligned:

  In an example from my machine, total buffer that I’ve given to SCIC goes
  from 0x410024566f84 to 0x410024567308.  From this same example, this
  call shifts my task_context_buffer from 0x410024567208 to
  0x410024567240.

  This means that the task_context_buffer that used to range from
  0x410024567208 to 0x410024567308 instead now goes from 0x410024567240 to
  0x410024567340.

  When the memset() call at the end of scic_task_request_construct()
  clears out this task_context_buffer, it does so from 0x410024567240 to
  0x410024567340, effectively killing whatever buffer follows this
  allocation in memory."

djbw:
Use the kernel's PTR_ALIGN instead of
scic_sds_request_align_task_context_buffer() and SMP_CACHE_BYTES instead of
the local CACHE_LINE_SIZE definition.

TODO: These allocations really want to be better defined in a union rather
than opaque buffers carved up by macros.
Reported-by: Ross Zwisler <ross.zwisler@intel.com>
Signed-off-by: Jacek Danecki <Jacek.Danecki@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

When aborting a task context we need to be sure that the hardware has acted on
this request (retrieved the task context) before invalidating the remote node
context.  In the case of the "dummy" task context and remote node we do not
have the full state machine that goes through the complete tc abort and rnc
invalidate states.  Instead we ensure the hardware has seen and acted on
Signed-off-by: Jacek Danecki <Jacek.Danecki@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

Moving some of the chattiness of warning messages to debug so only the Linux
system messages are shown.
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

Adding support for PHY_FUNC_LINK_RESET and PHY_FUNC_DISABLE. This allow the
sysfs knob enable (both 0 and 1) and link_reset to work properly.
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

Core reworks to support stopping and re-starting the controller, lays the
groundwork for phy disable / re-enable and fixes other bugs around port/phy
setup/teardown.
Signed-off-by: Pawel Marek <pawel.marek@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

Observed that some devices return a d2h fis, treat like an sdb error fis.
Signed-off-by: Piotr Sawicki <piotr.sawicki@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

There is a condition whereby TCs (task contexts) can jump to the head of
the round robin queue causing indefinite starvation of pending tasks.
Posting a TC to a suspended RNC (remote node context) causes the
hardware to select that task first, but since the RNC is suspended the
scheduler proceeds to the next task in the expected round robin fashion,
restoring TC arbitration fairness.
Signed-off-by: Tomasz Chudy <tomasz.chudy@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

Prepare the timer api for the arrival of dynamic creation and
destruction events from the core.  It pretended to do this previously
but the core to date only used it in a static init-time only fashion.
This is an interim fix until a cleaner event queue can be developed.

1/ make all locking external to the api (add WARN_ONCE to verify)
2/ add a timer_destroy interface (to be used by the core)
3/ use del_timer_sync() prior to deallocating timer data
4/ delete the "timer_list" indirection, we only have timers allocated
   for the isci_host
5/ fix detection of timer list allocation errors
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

Undo the open coded and incorrect translation of the oem parameter sas
address to its libsas expected format.
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

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

Renaming the callbacks to apparopriate event notify calls for the LLDD.
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

Remove abstraction for SG building and get rid of callbacks for getting
DMA memory mapping.
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

We can copy the data directly to and from sg for SATA PIO read operations.
There is no reason to involve the hardware SGL. In the process we also need
to kmap the sg because we don't know where that can come from.

We also do to not call phys_to_virt(). The driver already has the information.
We can just calculcate the appropriate offets.
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

These macros are not necessary. We can do 64bit math directly.
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

Sending aborts/resets to SAS/SATA targets in APC mode eventually causes
an assert in scic_sds_apc_agent_link_up().  We need to handle the hard reset
case for apc mode ports.
Signed-off-by: Piotr Sawicki <piotr.sawicki@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

Update the SCI Core to comprehend the changes in the TC completion
codes from A0 to B0.  Specifically, there isnew R_ER code
differences for command and data FISes.

Changes are as follows:

1) 0x16 now additionally indicates an R_ERR received for a COMMAND
FIS being sent to a SATA target.  0x16 for SSP still indicates a
NAK received for a COMMAND frame.  Fix is to retry TC to be compliant
with SATA spec or ensure proper error handling of return value
(not spec compliant I don't believe).
2) 0x1B was previously called DONE_BREAK_RCVD for STP and
DONE_LL_ABORT_ERR for SSP.  Now it is universally called
DONE_LL_ABORT_ERR.  This is purely a superficial change.
3) 0x32 is no longer a reserved code.  Now it indicates
DONE_CMD_SDMA_ERR for STP/SSP.  There was a fatal error on the
SDMA for a command IU (includes Raw frames).  Consider retry,
but at a minimum gracefully fail the request.
4) 0x33 is no longer a reserved code.  Now it indicates
DONE_CMD_LL_ABORT_ERR for SSP.  There was a break receivd
during transmission of a command IU.  Consider retry, but
at a minimum gracefully fail the request.
Signed-off-by: Tomasz Chudy <Tomasz.Chudy@intel.com>
Signed-off-by: Jacek Danecki <Jacek.Danecki@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>