Bluetooth: Use delayed_work for connection timeout

Bluetooth rx task runs now in a workqueue, so it a good approach run any
timer that share locking with process context code also in a workqueue.

Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
 Bluetooth: Use delayed work for advertisiment cache timeout

As HCI rx path is now done in process context it makes sense to do all the
timer in process context as well.

Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
Bluetooth: hci_conn_auto_accept() doesn't need locking

It doesn't really touch any sensitive information about hdev. So no need
to lock here.

Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
Bluetooth: Move L2CAP timers to workqueue

L2CAP timers also need to run in process context. As the works in l2cap
are small we are using the system worqueue.

Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
Bluetooth: Don't use spin_lock socket lock anymore

We now run everything in process context, so the mutex lock is the best
option. But in some places we still need the bh_lock_sock()

Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
Bluetooth: Remove sk_backlog usage from L2CAP

We run everything in the same lock now. The backlog queue is useless now

Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
Bluetooth: move hci_task_lock to mutex

Now we can sleep in any path inside Bluetooth core, so mutex can make
sense here.

Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
Bluetooth: convert chan_lock to mutex

spin lock doesn't fit ok anymore on the new code based on workqueues.

Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
Bluetooth: remove struct hci_chan_hash

Only the list member of the struct was used, so we now fold it into
hci_conn.

Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
Bluetooth: Use RCU to manipulate chan_list

Instead of using tasklet_disable() to prevent acess to the channel use, we
can use RCU and improve the performance of our code.

Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
Bluetooth: convert conn hash to RCU

Handling hci_conn_hash with RCU make us avoid some locking and disable
tasklets.

Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
Small TYpos fix.
Bluetooth: Don't disable tasklets to call hdev->notify()

It's pointless, we aren't protecting anything since btusb_notify()
schedules a work to run, then all it operation happens without protection.
If protection is really needed here, we will fix it further.

Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
Bluetooth: Move command task to workqueue

As part of the moving on all the Bluetooth processing to Process context.

Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
Bluetooth: convert tx_task to workqueue

This should simplify Bluetooth core processing a lot.

Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
Bluetooth: convert info timer to delayed_work

Another step of remove interrupt context from Bluetooth Core.
Use the system workqueue.

Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
Bluetooth: invert locking order in connect path

This move some checking code that was in l2cap_sock_connect() to
l2cap_chan_connect(). Thus we can invert the lock calls, i.e., call
lock_sock() before hci_dev_lock() to avoid a deadlock scenario.

Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
Bluetooth: Change l2cap chan_list to use RCU

This list has much more reads than writes, so RCU makes senses here, also
it avoid deadlock against the socket lock.

Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
Bluetooth: Use new alloc_workqueue()

Update hdev workqueue API usage to use the new interface, this new
interface also allow us to mark this workqueue as WQ_HIGHPRI, so now rx
and tx work gets higher priority when running.

Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
Bluetooth: Remove work_add and work_del from hci_sysfs

As we run in process context now we don't need worqueue to add e del from
sysfs.

Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>