Background: userspace daemons registration protocol for Hyper-V utilities
drivers has two steps:
1) daemon writes its own version to kernel
2) kernel reads it and replies with module version
at this point we consider the handshake procedure being completed and we
do hv_poll_channel() transitioning the utility device to HVUTIL_READY
state. At this point we're ready to handle messages from kernel.

When hvutil_transport is in HVUTIL_TRANSPORT_CHARDEV mode we have a
single buffer for outgoing message. hvutil_transport_send() puts to this
buffer and till the buffer is cleared with hvt_op_read() returns -EFAULT
to all consequent calls. Host<->guest protocol guarantees there is no more
than one request at a time and we will not get new requests till we reply
to the previous one so this single message buffer is enough.

Now to the race. When we finish negotiation procedure and send kernel
module version to userspace with hvutil_transport_send() it goes into the
above mentioned buffer and if the daemon is slow enough to read it from
there we can get a collision when a request from the host comes, we won't
be able to put anything to the buffer so the request will be lost. To
solve the issue we need to know when the negotiation is really done (when
the version message is read by the daemon) and transition to HVUTIL_READY
state after this happens. Implement a callback on read to support this.
Old style netlink communication is not affected by the change, we don't
really know when these messages are delivered but we don't have a single
message buffer there.
Reported-by: NBarry Davis <barry_davis@stormagic.com>
Signed-off-by: NVitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

vmbus_teardown_gpadl() can result in infinite wait when it is called on 5
second timeout in vmbus_open(). The issue is caused by the fact that gpadl
teardown operation won't ever succeed for an opened channel and the timeout
isn't always enough. As a guest, we can always trust the host to respond to
our request (and there is nothing we can do if it doesn't).
Signed-off-by: NVitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

In some cases create_gpadl_header() allocates submessages but we never
free them.
Signed-off-by: NVitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

We use messagecount only once in vmbus_establish_gpadl() to check if
it is safe to iterate through the submsglist. We can just initialize
the list header in all cases in create_gpadl_header() instead.
Signed-off-by: NVitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

When we crash from NMI context (e.g. after NMI injection from host when
'sysctl -w kernel.unknown_nmi_panic=1' is set) we hit

    kernel BUG at mm/vmalloc.c:1530!

as vfree() is denied. While the issue could be solved with in_nmi() check
instead I opted for skipping vfree on all sorts of crashes to reduce the
amount of work which can cause consequent crashes. We don't really need to
free anything on crash.
Signed-off-by: NVitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Joe Perches points out [1] that this pattern isn't currently safe.
This driver doesn't really need the zeroing semantic anyway;
by restructuring the code slightly we can initialize all the
fields of the structure up front instead.

[1] https://lkml.kernel.org/r/1469729491.3998.58.camel@perches.comSigned-off-by: NChris Metcalf <cmetcalf@mellanox.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Replace explicit computation of vma page count by a call to
vma_pages()
Signed-off-by: NMuhammad Falak R Wani <falakreyaz@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

v3.20 doesn't exist. heartbeat_enable was actually added in v4.4.
Signed-off-by: NAlexandre Belloni <alexandre.belloni@free-electrons.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

When building with W=1, the __scif_rma_destroy_tcw function
causes a harmless warning about an argument variable that is
modified but not used:

drivers/misc/mic/scif/scif_dma.c: In function ‘__scif_rma_destroy_tcw’:
drivers/misc/mic/scif/scif_dma.c:118:27: error: parameter ‘ep’ set but not used [-Werror=unused-but-set-parameter]

In this case, we can just remove the argument, since all callers
are in the same file.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
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>

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_amthif_read have only one difference from mei_read, it is not
calling mei_read_start().
Make mei_read_start return immediately for amthif client and drop the
special mei_amthif_read function.
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 supports only one pending read per host client, in order to
support  issuing of consecutive reads the driver  queues read requests
internally and send them to the firmware after pending 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>

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>

With the introduction of the receive control flow credits prefixed with
rx_ we add tx_ prefix to the variables and function used for tracking
the transmit control flow credits.
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Use RX flow control counter in the host client structure to
track the number of simultaneous outstanding reads.
This eliminates search in queues and makes ground for
enabling for parallel read.
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 read callbacks for the fixed address clients, that don't have flow
control are built now on the receive path. In order to have a single
allocation place we remove the allocation from the read request.
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 read callback is always prepared with MTU-sized buffer and the FW
can't send more than the MTU in one message.
Checking for buffer existence and krealloc to increase receive buffer
size are redundant and may be safely discarded.
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>

Open code mei_clear_lists into its only caller mei_amthif_releas
and drop unused parameter 'dev' form from mei_clear_list function.
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 Fixed address clients do not work with the flow control, and the
packet RX callback was allocated upon TX with anticipation of a
following RX. This won't work if the clients with unsolicited Rx. Rather
than preparing read callback upon a write we allocate one directly on
the reciev path if one doesn't exists.
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>

Store the file associated with a client in the host client structure,
this enables dropping the special amthif client file pointer from struct
mei_device, and this is also a preparation for changing the way rx
packet allocation for fixed_address clients
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>

Move read cb to the completion queue if a read finds out that client
is not connected. This expedite user space reader wake on error
condition.
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>

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>

In mei_hbm_cl_hdr buf argument was not described
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>

Schedule link reset if failed to perform runtime suspend or resume.
Set active runtime pm stte on link reset
to clean runtimr pm error, if present.
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_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>

Use mei_cl_alloc_cb wrapper instead of open code steps
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>

Incorporate the mei_amthif_send_cmd code into its only caller:
mei_amthif_run_next_cmd
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>

Currently the poll function is bailing early for amthif client and
ignores requests for async events notifications.
Move async event processing before amthif to enable async events
notifications on amthif 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>

iamthif_current_cb was used in request cancel in amthif code.
Now a canceled request is discarded only at the end of the processing
and the variable lost its purpose and can be safely removed.
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>

Currently, all requests cancelled by the user are immediately removed
from the queues. Such removal can cause unexpected behavior in the case
when a request is partially written or a  reply is received after the
request is cancelled.  To resolve this a request is always fully
processed and the result is discarded in case the request was canceled.
This completes the partial fix in commit:
9d04ee11 ("mei: amthif: discard not read messages")
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>

AMTHIF code now uses read completed queue to store replies from the FW.
It is possible to send the next request as soon as a read from the FW is
completed. With these changes we don't need the READ_COMPLETE state.
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>

Splitting a command string could lead to unintended arguments.  Use an
argument list in the execute() function instead.
Signed-off-by: NValentin Rothberg <valentinrothberg@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

'symbol' and 'feature' are used synonymously to refer to Kconfig symbols
(configs, menus, etc.).  Use the term 'symbol' to have a consistent
terminology and to make the code more comprehensible.
Signed-off-by: NValentin Rothberg <valentinrothberg@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Fix pylint and pep8 warnings to have a consistent syntax and style.
Signed-off-by: NValentin Rothberg <valentinrothberg@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Replace the deprecated OptionParser with ArgumentParser, as recommended
by pylint.
Signed-off-by: NValentin Rothberg <valentinrothberg@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Python 2 is slowly dying, so port the script to Python 3.
Signed-off-by: NValentin Rothberg <valentinrothberg@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Use subprocess and set shell to False to avoid potential shell
injections.
Reported-by: NBernd Dietzel <tcpip@t-online.de>
Signed-off-by: NValentin Rothberg <valentinrothberg@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Only print the ANSI colour escape codes if stdout is a TTY. Useful if
redirecting output to a file or piping to another script.

Also add a new option, --no-color, if the user wants to disable colour
output for whatever reason.
Signed-off-by: NAndrew Donnellan <andrew.donnellan@au1.ibm.com>
Acked-by: NValentin Rothberg <valentinrothberg@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>