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>

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>

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>

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>

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>

mei_io_cb_alloc_buf have a single caller :mei_cl_alloc_cb. After amthif
stopped using it, the code can be integrated into the caller and the
function can be dropped.
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>

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 FW can initiate client disconnection only because an error
condition, hence it make sense to bump the debug message to the warning
level to have an entery in the log.
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>

Clean write and write_waiting queues in disconnect.
Requests in those queues are stale and processing will lead to
fat warnings.

In multi thread operations on disconnect and in FW disconnect case -
write/read/event waiters should end wait and return error.
Wake all waiters for disconnecting client to achieve that.

Drop wake all and write queue clean on reset,
as now we waking all waiters and cleaning write queues on disconnect.
No need to do it twice.
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 struct file file pointer is used as an opaque handle to for a
connected client, for this part the pointer should be immutable and
should be set to count.
Reviewed-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>

Instead of integrating the iAMT watchdog in the mei core driver
we will create a watchdog device on the mei client bus and
create a driver for it.

This patch removes the watchdog code from the mei core 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>

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>

A process can be informed about client notification also via
SIGIO with POLL_PRI event.
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

mei_cl_notify_get is to be called by a host client
to wait, receive, and ack the event notification.
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>

Add per client notification request infrastructure
that allows client to enable or disable async
event notification.
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>

Fixed address is simplified FW client that doesn't require
connection and doesn't support flow control.
So it can be only one host client per fixed FW client.
Fixed client access is available only for drivers on mei bus,
connection from user-space is blocked.
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>

Keep a pointer to associated me client in the host client object to
eliminate me client searches. Check if the me client is active in the
firmware by checking if its is linked on the me clients list
Add accessors for the me client properties from host client.
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>

Simplify connect state machine by changing the logic around
Connection request in progress - only check if we have a callback in
relevant queue.
Extract common code into mei_cl_send_connect() function
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>

Split disconnected state into two parts first reception disconnect
response from the firmware and second actually setting of disconnected
state.  Book keeping data are needed for processing and after firmware
disconnected the client and are cleaned when setting the disconnected
state in mei_cl_set_disconneted() function.
Add mei_cl_send_disconnect to reduce code duplication.
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>

The function mei_cl_is_transitioning is just opposite
of mei_cl_is_connected. What we actually wanted to
check is if we lost connection so we can discard
the check for transition and check for 'not connected'
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

In mei_host_client_init function we enable the all internal
connected clients including NFC. This is done before we set the device
to enabled state and let userspace call open.
We need to check only for MEI_FILE_CONNECTED in mei_cl_is_connected
in order to enable the communication with the clients before
MEI_DEV_ENABLED is set.
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Replace clunky read state machine with read stack
implemented as per client read list, this is important
mostly for mei drivers with unsolicited reads
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Add convenient wrapper mei_cl_alloc_linked
to simplify error handling
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

We set the operation type at initialization time as each cb is used only
for a single type of operation

As a byproduct we add a convenient wrapper for allocating cb with
the data buffer.
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The callback structure is used exclusively for reading or writing
therefore there is no reason to hold both response and request buffers
in the callback structure
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Reduce code duplication in amthif by reusing
regular client read functions.

The change also removes the need for amthif
own buffering
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

1. Use rw lock to access the me_clients list

2. Reuse already defined find functions also when
removing particular me client

3. Add wrappers for addition  and deletion
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

To support dynamic addition and removal of
me clients we add reference counter.

Update kdoc with locking requirements.
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

For purpose of adding testing HW we would like
to get rid of pci dependency in generic mei code
This patch provides only straight forward changes
FW status and prob quirks need to be handled separately
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

When handling dynamic clients there might be a race
scenario in which two me clients with the same me
address would be linked in the me clients list,
therefore we need to search by both uuid and me address.
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

To support dynamic addition/remove we add wrappers
for removal of me clients
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

For support of dynamic addition and removal of me clients
it is more convenient to use a list instead of static array
as is use now.
As the first step of the transition to the new data structure
we change the lookup function so it returns me client address
instead of an index.
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Replace open coded loop with an existing service function:
mei_io_list_flush
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>

Fix checkpatch error
return is not a function, parentheses are not required
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Write callbacks are released on the write completed path but
when file handler is closed before the writes are
completed those are left dangling on write and write_waiting queues.

We add mei_io_list_free function to perform this task

Also move static functions to client.c form client.h

Cc: stable <stable@vger.kernel.org> # 3.11+
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>

Since txe use doorbell and not circular buffer
we have to cheat in write slot counting, txe always consume all the
slots upon write. In order for it to work we need to track
slots using mei_hbuf_empty_slots() instead of tracking it in mei layer
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Bus layer omitted check for client state transition while waiting
for read completion
The client state transition may occur for example as result
of firmware initiated reset

Add mei_cl_is_transitioning wrapper to reduce the code
repetition.:

Cc:  <stable@vger.kernel.org> # 3.9+
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>