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>
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>
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: Maciej Trela <maciej.trela@intel.com>
Signed-off-by: Dan 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: Christoph Hellwig <hch@infradead.org>
Cc: Jeff Garzik <jeff@garzik.org>
Signed-off-by: Edmund Nadolski <edmund.nadolski@intel.com>
Signed-off-by: Dan 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: Maciej Trela <maciej.trela@intel.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Edmund Nadolski <edmund.nadolski@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Dan Williams