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>

In case of link reset all blocked writes should be interrupted.
Note, that currently blocking write is used only through bus layer.
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>

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>

In case of link reset all waiting readers should be interrupted.
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>

Switch using cl->rx_wait wait queue also for amthif, there is nothing
special about amthif in that matter in Rx flow.
The cl->wait is reserved for hbm flows and asynchronous events
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 duplicated parameter validation from mei_amthif_write functions,
The parameter check is already performed by the caller function
mei_write
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>

Now when we have per client rd_completed list we can remove
the amthif specific amthif_rd_complete_list.
In addition in the function mei_amthif_read do not loop over the
rd_completed list like the original code as the code path is unlocked.
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>

A next amthif write can be executed only after the previous one has
completed.
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 driver uses three names file, fp, and file_object for
struct file type. To improve code clarity and adjust to my taste
rename file_object to more common and shorter fp.
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>

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>

If empty message come from FW (buf_idx == 0) then the current code will
still try to copy data from not filled buffer to the user-space,
instead the code should behave the same as when end of a message
has been reached, clean resources and return 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>

If registering of character device failed stop the device properly.
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>

HBM features list is ready while sending enumerate request and
enumerating clients, output it to debugfs in these states too.
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 case of many active host clients clients (41 and more) 1K buffer
is not enough for full information print.
Calculate buffer size according to real clients number.
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 tracing events also for reading and writing pci configuration space
<debugfs>/tracing/events/mei/mei_pci_reg_{read,write}
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

For Intel SKL platform the ME device can inform the host via
asynchronous notification that the watchdog feature was activated
on the device. The activation doesn't require reboot.
In that case the driver registers the watchdog device with the kernel.
Reviewed-by: NGuenter Roeck <linux@roeck-us.net>
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 entry for displaying whether the device has activated or
deactivated watchdog fw application.

cat <debugfs>/mei_wdt/activation
activated | deactivated
Reviewed-by: NGuenter Roeck <linux@roeck-us.net>
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

For Intel Broadwell and newer platforms, the ME device can inform
the host whether the watchdog functionality is activated or not.
If the watchdog functionality is not activated then the watchdog interface
can be not registered and eliminate unnecessary pings and hence lower the
power consumption by avoiding waking up the device.
The feature can be deactivated also without reboot
in that case the watchdog device should be unregistered at runtime.

The information regarding the deactivation is reported
in the ping response command. In runtime case the unregistration
has to be run from a worker so that the ping initiated by the watchdog
core completes. Otherwise the flow will deadlock on watchdog
core mutex which both ping and unregistration acquire.
Reviewed-by: NGuenter Roeck <linux@roeck-us.net>
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 iAMT WD client has to be whitelisted sice it has two connections
and is filtered out by number_of_connections fixup.
Also the API has changed for BDW and SKL but firmware haven't updated
the protocol version.
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 entry for displaying current watchdog internal state

cat <debugfs>/mei_wdt/state
IDLE|START|RUNNING|STOPPING
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Create a driver with the generic watchdog interface
for the MEI iAMT watchdog device.
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>

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>

We left few function prototypes in the header file after
moving nfc logic to bus.
Signed-off-by: NTomas Winkler <tomas.winkler@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>

The MEI  FW can receive only one flow control for read.
Currently the driver only checks if a flow control credit was already
sent and read is pending in the rd_pending queue, but it also has to
check if flow control credit already queued in the write control queue
to prevent sending more than one flow control credits.
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 uuid from the debug messages in bus-fixup.c
as this is already part of the device name.
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Function nand_setup_cmd_params has 2 goals-

-Initialize the cmd_params field so that it can be used to send and read
commands from the device.
-Get a bus address for the allocated memory to transfer to the device.

Replace the combination of devm_kzalloc and _pa() with dmam_alloc_coherent.
Coherent mapping guarantees that the device and CPU are in sync.
Signed-off-by: NShraddha Barke <shraddha.6596@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Add ACPI binding to the android pipe driver
Signed-off-by: NJason Hu <jia-cheng.hu@intel.com>
Signed-off-by: NJin Qian <jinqian@android.com>
Signed-off-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

For reading and writing guest user space buffers, currently the kernel
sends the guest virtual address of the buffer to the pipe device. This
virtual address has to be first converted to a guest physical address.
Doing this translation on the QEMU side is inefficient and requires
additional handling when KVM is enabled, whose implementation would
either incur intrusive changes to QEMU's KVM support code or suffer
from poor performance, see commit 08c7228c50f8 ("x86-kvm: only sync
SREGS when doing address translation") of $AOSP/external/qemu for
details, and thus should be avoided if possible.

There is a TODO comment in hw/misc/android_pipe.c in the new Android
emulator source tree ($AOSP/external/qemu-android) which requests that
the translation be done on the kernel side and that physical addresses
be passed to the device instead of virtual ones. Once the QEMU-side
implementation is done, the kernel will need to support both the new
paddr-based pipe device and the old vaddr-based one (which will
continue to be used by the classic emulator). This patch achieves that
by leveraging the device version register available in the new device.

See https://android-review.googlesource.com/128280 for the QEMU-side
patch.

In addition, use the mmap semaphore (in read mode) to safeguard the
call to get_user_pages().
Signed-off-by: NYu Ning <yu.ning@intel.com>
Signed-off-by: NJin Qian <jinqian@android.com>
Signed-off-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Enable CONFIG_GOLDFISH for MIPS platforms.
Signed-off-by: NMiodrag Dinic <miodrag.dinic@imgtec.com>
Signed-off-by: NJin Qian <jinqian@android.com>
Signed-off-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

On PIPE_ERROR_AGAIN, just stopping in the middle of a transfer and
returning the number of bytes actually handled is the right behavior.

Other errors should be returned on the next read() or write() call.
Continue logging those until we confirm nothing actually relies on the
existing (wrong) behavior of dropping errors on the floor.
Signed-off-by: NGreg Hackmann <ghackmann@google.com>
Signed-off-by: NJin Qian <jinqian@android.com>
Signed-off-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Add bindings so we don't need to rely on goldfish virtual bus for
probing any more, which means we don't need ARM and MIPS goldfish
board code for instantiating the bus.

In the long term we would like to move towards replacing the Android
pipe with virtio-vsock that is currently under development.
Signed-off-by: NGreg Hackmann <ghackmann@google.com>
Signed-off-by: NJin Qian <jinqian@android.com>
Acked-by: NRob Herring <robh@kernel.org>
Signed-off-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The existing code had a troubling TODO statement concerning the fact
that it just did a check if the page that the QEMU backend was going to
read from / write to was there before the call to the QEMU backend and
then relying on the fact that the page stayed around, even in a
preemptible SMP kernel.  Obviously the page could go away or be
reassigned, and strange things may happen.

Further, writes were not tracked, so any use of COW or KSM-like
features would break completely.  Probably that was never used by adbd
(the only current active user of the pipe), but could prove much more
dangerous for the GPU passthrough mechanism.

Instead, use get_user_pages() as the comment suggested and cleanup the
error path and add the set_page_dirt() call on a successful read
operation.

Also clarify the count used to return from successful read/write calls
and use Linux style commentary in various places of the file.

Note: The "just ignore error and return whatever we read so far" error
handling is really quite horrific.  I cannot change it without a more
careful study of all user space ABIs reliance on this 'feature'.
Signed-off-by: NChristoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: NJin Qian <jinqian@android.com>
Signed-off-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

It just makes it harder to figure out which commands are being used.
Signed-off-by: NAlex Bennée <alex.bennee@linaro.org>
Signed-off-by: NJin Qian <jinqian@android.com>
Signed-off-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

On new virtual devices, the goldfish virtual bus can be replaced with
autoprobing infrastructure like Device Tree.  Refactor the goldfish
kernel configs to better accommodate this.

Move the goldfish platform into a menuconfig in the style of the chrome
platform, and separate the goldfish bus into its own config option.
Signed-off-by: NGreg Hackmann <ghackmann@google.com>
Signed-off-by: NJin Qian <jinqian@android.com>
[Corrected a tristate to bool]
Signed-off-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>