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

Some of the chain walks to get back to our dev are invalid.

isci_remote_device_change_state: delete rather than adding conditional deref
chain walking
isci_request_change_state: fix, it was being called too early
isci_request_ssp_io_request_get_lun: fix compile breakage hidden by ifdef DEBUG
Signed-off-by: NMaciej Trela <maciej.trela@intel.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

The lldd actively disallows requests in the "starting" state.  Retrying
or holding off commands in this state is sub-optimal:
1/ it adds another state check to the fast path
2/ retrying can cause libsas to give up

However, isci's ->lldd_dev_found() routine already waits for controller
start to complete before allowing further progress.  Checking the
"starting" state in isci_task_execute_task and the isr is redundant and
misleading.  Clean this up and introduce a controller-wide event queue
to start reeling in "completion" proliferation in the driver.

The "stopping" state cleanups are in a similar vein, rely on the the isr
and other paths being precluded from occurring rather than implementing
state checking logic.
Reported-by: NChristoph Hellwig <hch@infradead.org>
Cc: Jeff Garzik <jeff@garzik.org>
Signed-off-by: NEdmund Nadolski <edmund.nadolski@intel.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Support for the up to 2x4-port 6Gb/s SAS controllers embedded in the
chipset.

This is a snapshot of the first publicly available version of the driver,
commit 4c1db2d0 in the 'historical' branch.

   git://git.kernel.org/pub/scm/linux/kernel/git/djbw/isci.git historical
Signed-off-by: NMaciej Trela <maciej.trela@intel.com>
Signed-off-by: NDave Jiang <dave.jiang@intel.com>
Signed-off-by: NEdmund Nadolski <edmund.nadolski@intel.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>