block: prepare I/O context code for BFQ-v3r2 for 3.0

BFQ uses struct cfq_io_context to store its per-process per-device data,
reusing the same code for cic handling of CFQ.  The code is not shared
ATM to minimize the impact of these patches.

This patch introduces a new hlist to each io_context to store all the
cic's allocated by BFQ to allow calling the right destructor on module
unload; the radix tree used for cic lookup needs to be duplicated
because it can contain dead keys inserted by a scheduler and later
retrieved by the other one.

Update the io_context exit and free paths to take care also of
the BFQ cic's.

Change the type of cfqq inside struct cfq_io_context to void *
to use it also for BFQ per-queue data.

A new bfq-specific ioprio_changed field is necessary, too, to avoid
clobbering cfq's one, so switch ioprio_changed to a bitmap, with one
element per scheduler.

Signed-off-by: Fabio Checconi <fabio@gandalf.sssup.it>
Signed-off-by: Paolo Valente <paolo.valente@unimore.it>
Signed-off-by: Arianna Avanzini <avanzini.arianna@gmail.com>

Conflicts:

	block/Kconfig.iosched
block: cgroups, kconfig, build bits for BFQ-v3r2-3.0

Add a Kconfig option and do the related Makefile changes to compile
the BFQ I/O scheduler.  Also let the cgroups subsystem know about the
BFQ I/O controller.

Signed-off-by: Fabio Checconi <fabio@gandalf.sssup.it>
Signed-off-by: Paolo Valente <paolo.valente@unimore.it>
Signed-off-by: Arianna Avanzini <avanzini.arianna@gmail.com>

Conflicts:

	block/Makefile
	include/linux/cgroup_subsys.h
block: introduce the BFQ-v3r2 I/O sched for 3.0

Add the BFQ-v3r2 I/O scheduler to 3.0.
The general structure is borrowed from CFQ, as much of the code. A (bfq_)queue
is associated to each task doing I/O on a device, and each time a scheduling
decision has to be taken a queue is selected and it is served until it expires.

The main differences are:
    - Slices are given in the service domain: tasks are assigned budgets,
      measured in number of sectors. Once got the disk, a task must
      however consume its assigned budget within a configurable maximum time
      (by default, the maximum possible value of the budgets is automaticall
      computed to comply with this timeout). This allows the desired latency
      vs "throughput boosting" tradeoff to be set.

    - Budgets are scheduled according to a variant of WF2Q+, implemented
      using an augmented rb-tree to take eligibility into account while
      preserving an O(log N) overall complexity.

    - A low-latency tunable is provided; if enabled, both interactive and soft
      real-time applications are guaranteed very low latency.

    - Latency guarantees are preserved also in presence of NCQ.

    - Useful features borrowed from CFQ: cooperating-queues merging (with
      some additional optimizations with respect to the original CFQ version),
      static fallback queue for OOM.

    - BFQ supports full hierarchical scheduling, exporting a cgroups
      interface.  Each node has a full scheduler, so each group can
      be assigned its own ioprio and an ioprio_class.

    - If the cgroups interface is used, weights can be explictly assigned,
      otherwise ioprio values are mapped to weights using the relation
      weight = IOPRIO_BE_NR - ioprio.

    - ioprio classes are served in strict priority order, i.e., lower
      priority queues are not served as long as there are higher priority
      queues.  Among queues in the same class the bandwidth is distributed
      in proportion to the weights of each queue. A very thin extra bandwidth
      is however guaranteed to the Idle class, to prevent it from starving.

Regarding what has not changed it is worth noting:
    - the handling of cfq_io_contexts to associate queues to tasks.
      Much of the code has been reused just renaming it.  (There is room for
      code sharing with CFQ but we wanted to minimize the impact of this
      patch.)

    - The handling of async queues.

    - The handling of idle windows.

    - The handling of merging.

    - The heuristics to assert that a task is worth an idle window (with
      minor modifications to hw_tag/CIC_SEEKY detection).

Signed-off-by: Paolo Valente <paolo.valente@unimore.it>
Signed-off-by: Arianna Avanzini <avanzini.arianna@gmail.com>
net: wireless: bcmdhd: Add FW reloading in case of FW hang

Signed-off-by: Dmitry Shmidt <dimitrysh@google.com>
net: wireless: bcmdhd: Decrease event wake_lock timeout to 1500 ms

Signed-off-by: Dmitry Shmidt <dimitrysh@google.com>
net: wireless: bcmdhd: Fix proper scan command even if request is NULL

Signed-off-by: Dmitry Shmidt <dimitrysh@google.com>
net: wireless: bcmdhd: Fix crash on dhdsdio_probe_attach() failure

Signed-off-by: Dmitry Shmidt <dimitrysh@google.com>
net: wireless: bcmdhd: Increase pm_notify callback priority

Make pm_notify callback to be called the first on suspend/resume path to
ensure it will always be called.

Signed-off-by: Dmitry Shmidt <dimitrysh@google.com>
net: wireless: bcmdhd: Always turn Off wlan power on interface down

Signed-off-by: Dmitry Shmidt <dimitrysh@google.com>
net: wireless: bcmdhd: Add 'wlan_ctrl_wake' wakelock

Signed-off-by: Dmitry Shmidt <dimitrysh@google.com>
net: wireless: bcmdhd: Fix FW hang recovery

- Reduce IOCTL responce timeout to 2 sec (from 20)
- Fix pending status in case of timeout
- Pass error code from dhd_is_associated() call
- Call cfg80211_disconnected() if no timeout detected

Signed-off-by: Dmitry Shmidt <dimitrysh@google.com>
net: wireless: bcmdhd: Move FW hang processign to work queue

Signed-off-by: Dmitry Shmidt <dimitrysh@google.com>
net: wireless: bcmdhd: Fix driver hang when resetting

bus->tx_max was not being initialized when we do a reset and
the driver is statically linked.  this led to about a 50%
chance that it would be considered an illegal value when
we send the mac address to the FW.  add code to initialize
it to a safe value until we receive the right value from the fw.

Bug: 5974574

Change-Id: I28ab25d97203ef075e5354c25f85a25daaff5594
Signed-off-by: Mike J. Chen <mjchen@google.com>
Signed-off-by: Dmitry Shmidt <dimitrysh@google.com>
net: wireless: bcmdhd: Fix frame sequence lag issue

Signed-off-by: Dmitry Shmidt <dimitrysh@google.com>