The read callback created from a flow control request for
a fixed address client have NULL in the file pointer.
Fill the file pointer using a data from a write callback.

This allows us to drop workaround introduced in:
commit eeabfcf5 ("mei: connection to fixed address clients from user-space")
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>

Since the driver now uses a list for storing read packets instead of
single variable a pending read is no longer blocking other connections.
A pending read will be discarded up the file closure.
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>

There is a possible integer overflow following by a buffer overflow
when accumulating messages coming from the FW to compose a full payload.
Occurrence of wrap around has to be prevented for next message size
calculation.
For unsigned integer the addition overflow has occurred when the
result is smaller than one of the arguments.
To simplify the fix, the types of buf.size and buf_idx are set to the
same width, namely size_t also to be aligned with the type of length
parameter in file read/write ops.
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>

Copy completed callback content to the user space
if we have such callback ready in the beginning of the read.
Simplify offset processing logic as byproduct.

This is a refinement for:
commit 139aacf7 ("mei: fix read after read 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>

fasync should return a negative value on error
and not poll mask POLLERR.

Cc: <stable@vger.kernel.org> # 4.3+
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Reported-by: NAl Viro <viro@ZenIV.linux.org.uk>
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>

Polling on priority events is translated on waiting for event
notification. One need to enable notification prior for
calling select or poll system call otherwise process
will not wait.
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 ioctl IOCTL_MEI_NOTIFY_SET for enabling and disabling
async event notification.
Add ioctl IOCTL_MEI_NOTIFY_GET for receiving and acking
an 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>

chrdev_open() increases reference counter on cdev->owner. Instead of
assigning the owner to mei subsystem, the owner has to be set to the
underlaying HW module (mei_me or mei_txe), so once the device is opened
the HW module cannot be unloaded.

Cc: <stable@vger.kernel.org> #3.17+
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 client info to debug prints in the read function to
ease on debugging efforts.
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 should be used for debug only.
The feaure is gated by "allow_fixed_address" control exposed in debugfs.
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>

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>

Replace open coded check for cl->state !=/== MEI_FILE_CONNECTED
with mei_cl_is_connected function.

Note that cl->state != MEI_FILE_CONNECTED is not the same
as cl->state == MEI_FILE_DISCONNECTED
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

mei_poll returned with POLLIN w/o checking whether the operation
has really completed.
remove redundant check and locking in amthif specific handler
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

struct kiocb now is a generic I/O container, so move it to fs.h.
Also do a #include diet for aio.h while we're at it.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

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>

Simplify disposal of io callback by removing the callback
implicitly from its lookup list inside mei_io_cb_free
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 code by reusing
regular client write functions.
Add completed flag to cb so amthif client can add
rx credits on write completion
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

On memory allocation failure mei_cl_irq_read_msg will
return with error that will cause device reset.
Instead we should propagate error to caller and
just clean the read queues.
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>

The interface is for applications that monitor
the fw health.

We use device_create_with_groups interface
to register attribute with the mei class device
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Fix Kdoc documentation formatting warnings
genertaed by ./scripts/kernel-doc
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>

Remove inclusion of linux/pci.h in mei layer
however we need to include the headers that before
got included implicitly from linux/pci.h.
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>

There is no need to log memory allocation errors as
this is already done by the memory subsystem.
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

There is no need for dynamic allocation for connect_data.
We can use variable on the stack and make code less
error prone and simple
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Handle ioctls in a switch statement so we can
add more commands easily
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>

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>

We need to support more then one mei interface
hence the simple misc devices is not longer an option

In order not break the user space a device with pci function 0
need to be linked to /dev/mei
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>

Adding power gating introduced new waiting state for client also during
connection attempt, a connection request can be queued for later either due
device is power gated or due to other on going connection.
We setting client connection state before start of full connect procedure so
in both cased the client state will be MEI_FILE_CONNECTING
which create interlock between the two connection attempts, both
detecting that another connection is in progress.

The interlock is resolved by moving client to connecting state
only upon connection request transmission, so the  first
cb in queue can be processed.
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>

Ignore client writing state during cb completion to fix a memory
leak.

When moving cbs to the completion list we should not look at
writing_state as this state can be already overwritten by next
write, the fact that a cb is on the write waiting list means
that it was already written to the HW and we can safely complete it.

Same pays for wait in poll handler, we do not have to check the state
wake is done after completion list processing.

Cc: stable@vger.kernel.org
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 cl_dbg for debug log messages in cl context

this also removes checkpatch warning:
quoted string split across lines
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Consistently display error on possible copy_from/to_user failures
use dev_dbg  so it cannot be abused to flood the kernel 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>