AMTHIF has special support in the mei drive, it handles multiplexing
multiple user space connection above single me client connection.
Since there is no additional addressing information there is a strict
requirement on the traffic order on each connection and on the "read
after write" order within the connection. This creates a lot of
complexity mostly because the other client types do not necessarily fall
under the same restriction.    After carefully studying the use of the
AMTHIF client, we came to conclusion that the multiplexing is not really
utilized by any application and we may safely remove that support and
significantly simplify the driver.
Signed-off-by: NAlexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

sched/headers: Prepare to move signal wakeup & sigpending methods from <linux/sched.h> into <linux/sched/signal.h>

Fix up affected files that include this signal functionality via sched.h.
Acked-by: NLinus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: NIngo Molnar <mingo@kernel.org>

Stop and unregister receive and notification callbacks
from the disable function, to allow its later re-enablement.
Signed-off-by: NAlexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The hardware module should not be unloaded if the bus
has active devices.
Get get_/put_ bus parent module upon client device
connection/disconnection, to prevent the hardware managing
module to disappear underneath.
Signed-off-by: NAlexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

A driver on the mei bus may rely on the availability
of the receive callback during driver remove() call, e.g. mei_wdt.
Move callbacks dismantling after the remove() call to unblock that scenario.
Signed-off-by: NAlexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Adjust function name in KDoc.

Fixes: d49dc5e7 (mei: bus: use mei_cldev_ prefix for the API functions)
Signed-off-by: NAlexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Enable non-blocking receive for drivers on mei bus, this allows checking
for data availability by mei client drivers. This is most effective for
fixed address clients, that lacks flow control.

This function adds new API function mei_cldev_recv_nonblock(), it
retuns -EGAIN if function will block.
Signed-off-by: NAlexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Split callbacks for RX and async notification events on mei bus to
eliminate synchronization problems and to open way for RX optimizations.
Signed-off-by: NAlexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Change life time of the client pointer, allocate it upon client device
creation and free it upon device destruction, instead of upon
connection and disconnection.
This helps to eliminate racy NULL checks in the bus code.
Signed-off-by: NAlexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Prepare the client write functions to set the internal flag in message
header. Carry both blocking and internal modes inside the transmit cb,
and call internal bus function  __mei_cl_send() with send mode bit mask.
The Internal flag should be added only on messages generated by the
driver.
Signed-off-by: NAlexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

A mei client driver on the mei client bus can call disconnect function on
already internal disconnected client.  A client can disconnect internally,
for example, during link reset or upon FW request. Those are legitimate
flows and we should not log an error message, hence we demote
'Already disconnected' message to the debug level.
Signed-off-by: NAlexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The callback context is redunant as all the information can be
retrived from the device struture of its private data.
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The device lock was unnecessary obtained in bus rescan work before the
amthif client search.  That causes incorrect lock ordering and task
hang:
...
[88004.613213] INFO: task kworker/1:14:21832 blocked for more than 120 seconds.
...
[88004.645934] Workqueue: events mei_cl_bus_rescan_work
...

The correct lock order is
 cl_bus_lock
  device_lock
   me_clients_rwsem

Move device_lock into amthif init function that called
after me_clients_rwsem is released.

This fixes regression introduced by commit:
commit 025fb792 ("mei: split amthif client init from end of clients enumeration")

Cc: <stable@vger.kernel.org> # 4.6+
Signed-off-by: NAlexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Enclose the boiler plate code of allocating a control/hbm command cb
and enqueueing it onto ctrl_wr.list in a convenient wrapper
mei_cl_enqueue_ctrl_wr_cb().

This is a preparatory patch for enabling consecutive reads.
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Correct errno on client disconnection is -ENODEV not -EBUSY

Cc: <stable@vger.kernel.org> #4.3+
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NAlexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

In the course of the read flow we want to wait for read completion only
if the read queue is empty.
However the calling list_empty(&cl->rd_completed) is a duplication as the
same check was performed by mei_cl_read_cb() and the waiting is skipped
if it returns not NULL.
Signed-off-by: NAlexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Ensure that mei_cl_read_start is called under the device lock
also in the bus layer. The function updates global ctrl_wr_list
which should be locked.

Cc: <stable@vger.kernel.org> #4.4+
Signed-off-by: NAlexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

If cldrv->probe() failed in mei_cl_device_probe(),
the mei module is left pinned.

The patch moves __module_get(THIS_MODULE) after cldrv->probe().

Found by Linux Driver Verification project (linuxtesting.org).
Signed-off-by: NAlexey Khoroshilov <khoroshilov@ispras.ru>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

There's no reason to duplicate the logic provided by scnprintf().
Signed-off-by: NRasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Fix double freeing of the cb that can happen if link reset kicks  in the
middle of blocked write from a device on the cl bus.

Free cb inside mei_cl_write function on failure and drop cb free
operation from callers, during a link reset the mei_cl_write function
returns with an error,  but the caller doesn't know if the cb was
already queued or not so it doesn't know if the cb will be freed upon
queue reclaim or it has to free it itself.
Signed-off-by: NAlexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The amthif FW client can appear after the end of client enumeration.
Amthif host client initialization is done now at FW client discovery
time.
Signed-off-by: NAlexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Since clients can be now added and removed during runtime
we need to run bus rescan whenever me_clients list is modified.
Signed-off-by: NAlexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The reserved host clients can be obsoleted now, a portion of the
platforms is shipped without iAMT enabled, where the reservation is not
relevant and for platforms with iAMT dynamic allocation is sufficient.
Dropping reserved ids makes enumeration more flexible and generic
Signed-off-by: NAlexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The bus data transfer interface was missing the check if the device is
in enabled state, this may lead to stack corruption during link reset.

Cc: <stable@vger.kernel.org> #4.0
Signed-off-by: NAlexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Call wake_up cl->ev_wait only in case there is no bus client registered
to the event notification.
Second, since we don't have exclusive waiter wake_up_interruptible_all
is not used correctly here.
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

In this particular case this more correct and safer to check if the RX
event is set in the event mask rather than query waitqueue_active
Since the check is already performed in the mei_cl_bus_rx_event
function,  it is just required to check for its return value.
Second, since we don't have exclusive waiter wake_up_interruptible_all
is not used correctly here.
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The mei bus fixup use dev_xxx services for printing
to kernel log so we need to setup the device name
prior to running fixup hooks.
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The correct lock order is
  cl_bus_lock
    device_lock
      me_clients_rwsem

This order was violated in bus rescan and remove routines
when me_client_rwsem was locked before cl_bus_lock.

Chain exists of:
[    4.321653]   &dev->device_lock --> &dev->me_clients_rwsem -->
&dev->cl_bus_lock
[    4.321653]
[    4.321679]  Possible unsafe locking scenario:
[    4.321679]
[    4.321693]        CPU0                    CPU1
[    4.321701]        ----                    ----
[    4.321709]   lock(&dev->cl_bus_lock);
[    4.321720]
lock(&dev->me_clients_rwsem);
[    4.321733]                                lock(&dev->cl_bus_lock);
[    4.321745]   lock(&dev->device_lock);
[    4.321755]
[    4.321755]  *** DEADLOCK ***
[    4.321755]
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

s/send/receive/
The buffer in the receive function is
not used for sending
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Use mei_cl_bus_ for internal bus function consistently.
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Use mei_cldev_ prefix for all mei client bus api functions
in order to resolve prefix conflict with functions that handle
client function and are defined in client.c
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Let me client device driver query of the device is connected
and hence enabled.
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Export the uuid and the protocol version of the underlying me client
for me client bus drivers usage.
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The device alias now looks like mei:S:uuid:N:*
In that way we can bind different drivers to clients with
different protocol versions if required.
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

export me client protocol version to sysfs and uevent
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

scripts/mod/file2alias.c:add_uuid()  convert UUID into a single string
which does not conform to the standard little endian UUID formatting.
This patch changes add_uuid() to output same format as %pUL and modifies
the mei driver to match the change.
Signed-off-by: NPrarit Bhargava <prarit@redhat.com>
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Enable drivers on mei client bus to subscribe
to asynchronous event notifications.
Introduce events_mask to the existing callback infrastructure
so it is possible to handle both RX and event notification.
Signed-off-by: NAlexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

MEI bus was designed around nfc and was hard to extend.
Instead of the hard coded way of adding the devices on the mei bus
we scan the whole me client list and create a device for each
eligible me client (mei_cl_bus_rescan); currently we support
only clients with single connection and fixed address clients.
NFC radio name detection is run as a fixup routine

The patch replaces handling the device list based on struct me_cl
to device list based on me_cl_devices. The creating a connection
is pushed from the device creation time to device enablement.
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Remove the dependency on struct ndev from the nfc device
name creation function so it is possible to use it
in a fixup routine
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Split the device registration into allocation and device struct
initialization, device setup, and the final device registration.
This why it is possible to run fixups and quirks during the setup stage
on an initialized device. Each fixup routine effects do_match flag.
If the flag is set to false at the end the device won't be
registered on the bus.
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>