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>

The shutdown handler quiesces the device, it performs link reset in
order to close all connections and notify the device that is not longer
managed by the driver.
This is essentially a stripped down version of the PCI remove() function
where only the necessary amount of work is done to stop any further
activity.
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The driver still struggles with firmwares that do not replay to the OS
version request. It is safe not waiting for the replay. First, the driver
doesn't do anything with the replay second the connection is closed
immediately, hence the packet will be just safely discarded in case it
is received and last the driver won't get stuck if the firmware won't
reply.

Cc: <stable@vger.kernel.org> #4.10+
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>

This patch fixes 'mei: synchronize irq before initiating a reset'
The patch had introduced a deadlock between irq thread and mei_reset()
as they are both holding the same device lock.

---> device_lock:
	mei_reset()
                        <---- interrupt thread
	                        device_lock
---> synchornize_irq()
       wait on interrupt thread == (dead lock)

The fix is to call synchronize_irq
prior to call locked mei_reset function.

Cc: <stable@vger.kernel.org> #4.10+
Fixes: f302bb0de6ac (mei: synchronize irq before initiating a reset)
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>

Parallel reads from multiple threads on a file descriptor
are not well defined and racy. It is safer to return to original
behavior and simply fail the additional read.
The solution is to remove request for next read credit.

Cc: <stable@vger.kernel.org> #4.9
Fixes: ff1586a7 ("mei: enqueue consecutive reads")
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>

In rare case the driver may lose connection with the device after device
reset due to a missed interrupt. The driver will unlock the flow by
generating an interrupt towards the firmware (HIG) when the device is in
the resetting state. The FW is able to ignore the interrupt during
orderly flow. The effected platforms are skylake and newer.
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>

Consolidate setting H_IG, an interrupt from host towards hw,
into a wrapper to eliminate code duplication.
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>

Use devm_ and pcim_ functions to make error handling
simpler and code smaller and tidier.

Based on original patch by
mei: me: use managed functions pcim_* and devm_*
https://lkml.org/lkml/2016/2/1/339Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NAlexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Specify in function names by which object is the io list filtered:
cl for a client and fp for file descriptor.
In that course a code duplication is resolved by dropping
mei_cl_read_cb_flush and mei_clear_list and using
mei_io_list_free_fp function.
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

mei_dev structure used struct mei_cl_cb type variables as for holding
callbacks list heads.  Replace them by the actual struct list_head
as there is no other info that is handled. This slims down
the mei_dev structure and mostly streamline the 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>

The amthif client connection is shared over multiple file descriptors.
In case a file descriptor was closed immediately after a write, the read
credits should be still available so the pending reads can be cleaned
from the queue, hence we cannot drop the control read list, this is
done only upon connection close.
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 order to prevent memory leak clean up the amthif command
queue upon disconnection. The issue may happen only on error path
as the command queue is cleaned upon file descriptor close.
And remove the cleanup from mei_cl_flush_queues as this code
is never reached for amthif client.
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>

On legacy HW, pre Skylake, the notifications are not supported,
return -EOPNOTSUPP in mei_cl_notify_get and prevent
waiting indefinitely.
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>

Request for a notification from a disconnected client will be ignored
silently by the FW but the caller should know that the operation hasn't
succeeded.
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>

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>

mei_cl_set_disconnected is used only in client.c,
so make it local to the file and mark static.
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_io_list_flush is used only in client.c
so make it local to the file and mark static.
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 we need to change the implementation, stop exposing internals.

Provide kref_read() to read the current reference count; typically
used for debug messages.

Kills two anti-patterns:

	atomic_read(&kref->refcount)
	kref->refcount.counter
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
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>

Sending OS version for support of TPM2_ChangeEPS() is required only
for SPT FW (HMB version 2.0) and newer.
On older platforms the command should be just ignored by the firmware
but some older platforms misbehave so it's safer to send the command
only if required.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=192051
Fixes: 7279b238 (mei: send OS type to the FW)
Signed-off-by: NAlexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Tested-by: NJan Niehusmann <jan@gondor.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The credentials handling was pushed to the write handlers
but error handling wasn't done properly.
Move write callbacks to completion queue to destroy them
and to notify a blocked writer about the failure

Fixes: 136698e5 (mei: push credentials inside the irq write handler)
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>

Since the newer HW sports two interrupts causes we cannot
just simply acknowledge the interrupts directly in the quick handler
and store the cause in the member variable, as the cause
will be overridden upon next interrupt while the interrupt thread
was not yet scheduled handling the previous interrupt.
The simple fix is to disable interrupts in quick handler
and acknowledge and enabled them in the interrupt thread.
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>

We need to synchronize irqs before issuing reset to make sure that the
clients communication is concluded and doesn't leak to the reset flow
and confusing the state machine.

This issue is happening during suspend/resume stress testing.
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Add MEI Lewisburg PCH IDs for Purley based workstations.

Cc: <stable@vger.kernel.org> # 4.8.x
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>

pm_runtime_autosuspend can take synchronous or asynchronous
paths, Because we are calling pm_runtime_mark_last_busy just before
this most of the cases it takes the asynchronous way. However,
when the FW or driver resets during already running runtime suspend,
the call will result in calling to the driver's rpm callback and results
in a deadlock on device_lock.
The simplest fix is to replace pm_runtime_autosuspend with
asynchronous pm_request_autosuspend.

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>

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>

Introduce a new host client state, MEI_FILE_UNINITIALIZED,
to distinguish client objects that was unlinked,
but not destroyed and can be linked again.
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>

Parameter renaming to fop_type was not reflected in KDoc

Fixes: 3030dc05 (mei: add wrapper for queuing control commands)
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 write buffer should not by modified so make it constant. Also
hitchhike some style fixes on the way in the interface and rename
mei_me_write_message to mei_me_hbuf_write for consistency.
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

A cb is always placed on the completion queue
during discarding queue. Hence this can be performed
upon discard.
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Tell the FW that we are running a sane OS and TPM2_ChangeEPS()
is supported. This workaround was added to support other broken OS
and we need to follow here. The command is sent just once at the boot time.
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>

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>

NFC version reply size checked against only header size, not against
full message size. That may lead potentially to uninitialized memory access
in version data.

That leads to warnings when version data is accessed:
drivers/misc/mei/bus-fixup.c: warning: '*((void *)&ver+11)' may be used uninitialized in this function [-Wuninitialized]:  => 212:2

Reported in
Build regressions/improvements in v4.9-rc3
https://lkml.org/lkml/2016/10/30/57

Fixes: 59fcd7c6 (mei: nfc: Initial nfc implementation)
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 HBM protocol version is negotiated during the setup phase, then settled
on a highest possible common version of the driver and the firmware.
The sysfs API advertises both negotiated and driver supported versions
in the device attributes.
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>