USB4 1.0 section 6.4.2.7 specifies a new field (PG) in notification
packet that is sent as response of hot plug/unplug events. This field
tells whether the acknowledgment is for plug or unplug event. This needs
to be set accordingly in order the router to send further hot plug
notifications.
To make it simpler we fill the field unconditionally. Legacy devices do
not look at this field so there should be no problems with them.
While there rename tb_cfg_error() to tb_cfg_ack_plug() and update the
log message accordingly. The function is only used to ack plug/unplug
events.
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Link: https://lore.kernel.org/r/20191217123345.31850-4-mika.westerberg@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
There are two ways to mark a port as unimplemented. Typical way is to
return port type as TB_TYPE_INACTIVE when its config space is read.
Alternatively if the port is not physically present (such as ports 10
and 11 in ICL) reading from port config space returns
TB_CFG_ERROR_INVALID_CONFIG_SPACE instead. Currently the driver bails
out from adding the switch if it receives any error during port
inititialization which is wrong.
Handle this properly and just leave the port as TB_TYPE_INACTIVE before
continuing to the next port.
This also allows us to get rid of special casing for Light Ridge port 5
in eeprom.c.
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Yehezkel Bernat <YehezkelShB@gmail.com>
Tested-by: Mario Limonciello <mario.limonciello@dell.com>
Now that the driver can handle every possible tunnel types there is no
point to log everything as info level so turn these to happen at debug
level instead.
While at it remove duplicated tunnel activation log message
(tb_tunnel_activate() calls tb_tunnel_restart() which print the same
message) and add one missing '\n' termination.
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Intel has done pretty major changes to the driver and we continue to do
so in the future as well. Add Intel as copyright holder of the files we
have done changes.
While there drop "Cactus Ridge" from the headers because this driver
works also with other Thunderbolt controllers.
No functional changes intended.
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Yehezkel Bernat <yehezkelshb@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Currently the driver logs quite a lot to the system message buffer even
when doing normal operations. This information is not useful for
ordinary users and might even annoy some.
For this reason convert most of the logs at info level to happen at
debug level instead. The nice output formatting is untouched.
Logging can be easily re-enabled by passing "thunderbolt.dyndbg" in the
kernel command line (or using the corresponding control file runtime).
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Yehezkel Bernat <yehezkelshb@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
dma_pool_destroy() already takes NULL pointer into account so there is
no need to check that again in tb_ctl_free().
Signed-off-by: zhong jiang <zhongjiang@huawei.com>
[mw: reword commit log a bit]
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Files removed in 'net-next' had their license header updated
in 'net'. We take the remove from 'net-next'.
Signed-off-by: David S. Miller <davem@davemloft.net>
Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.
By default all files without license information are under the default
license of the kernel, which is GPL version 2.
Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.
This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.
How this work was done:
Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,
Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.
The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.
The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.
Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).
All documentation files were explicitly excluded.
The following heuristics were used to determine which SPDX license
identifiers to apply.
- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.
For non */uapi/* files that summary was:
SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139
and resulted in the first patch in this series.
If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:
SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930
and resulted in the second patch in this series.
- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:
SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1
and that resulted in the third patch in this series.
- when the two scanners agreed on the detected license(s), that became
the concluded license(s).
- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.
- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).
- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.
- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.
In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.
Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.
Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.
In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.
Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct
This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.
These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In order to support things like networking over Thunderbolt cable, there
needs to be a way to switch the ring to a mode where it can be polled
with the interrupt masked. We implement such mode so that the caller can
allocate a ring by passing pointer to a function that is then called
when an interrupt is triggered. Completed frames can be fetched using
tb_ring_poll() and the interrupt can be re-enabled when the caller is
finished with polling by using tb_ring_poll_complete().
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Michael Jamet <michael.jamet@intel.com>
Reviewed-by: Yehezkel Bernat <yehezkel.bernat@intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
These are used by Thunderbolt services to send and receive frames over
the high-speed DMA rings.
We also put the functions to tb_ namespace to make sure we do not
collide with others and add missing kernel-doc comments for the exported
functions.
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Michael Jamet <michael.jamet@intel.com>
Reviewed-by: Yehezkel Bernat <yehezkel.bernat@intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When high-speed DMA paths are used to transfer arbitrary data over a
Thunderbolt link, DMA rings should be in frame mode instead of raw mode.
The latter is used by the control channel (ring 0). In frame mode each
data frame can hold up to 4kB payload.
This patch modifies the DMA ring code to allow configuring a ring to be
in frame mode by passing a new flag (RING_FLAG_FRAME) to the ring when
it is allocated. In addition there might be need to enable end-to-end
(E2E) workaround for the ring to prevent losing Rx frames in certain
situations. We add another flag (RING_FLAG_E2E) that can be used for
this purpose.
This code is based on the work done by Amir Levy and Michael Jamet.
Signed-off-by: Michael Jamet <michael.jamet@intel.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Yehezkel Bernat <yehezkel.bernat@intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When two hosts are connected over a Thunderbolt cable, there is a
protocol they can use to communicate capabilities supported by the host.
The discovery protocol uses automatically configured control channel
(ring 0) and is build on top of request/response transactions using
special XDomain primitives provided by the Thunderbolt base protocol.
The capabilities consists of a root directory block of basic properties
used for identification of the host, and then there can be zero or more
directories each describing a Thunderbolt service and its capabilities.
Once both sides have discovered what is supported the two hosts can
setup high-speed DMA paths and transfer data to the other side using
whatever protocol was agreed based on the properties. The software
protocol used to communicate which DMA paths to enable is service
specific.
This patch adds support for the XDomain discovery protocol to the
Thunderbolt bus. We model each remote host connection as a Linux XDomain
device. For each Thunderbolt service found supported on the XDomain
device, we create Linux Thunderbolt service device which Thunderbolt
service drivers can then bind to based on the protocol identification
information retrieved from the property directory describing the
service.
This code is based on the work done by Amir Levy and Michael Jamet.
Signed-off-by: Michael Jamet <michael.jamet@intel.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Yehezkel Bernat <yehezkel.bernat@intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
We will be using these when communicating XDomain discovery protocol
over Thunderbolt link but they might be useful for other drivers as
well.
Make them available through byteorder/generic.h.
Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Michael Jamet <michael.jamet@intel.com>
Reviewed-by: Yehezkel Bernat <yehezkel.bernat@intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
There is a mistake here where we accidentally use sizeof(TB_CFG_PKG_RESET)
instead of just TB_CFG_PKG_RESET. The size of an int is 4 so it's the
same as TB_CFG_PKG_NOTIFY_ACK.
Fixes: d7f781bfdb ("thunderbolt: Rework control channel to be more reliable")
Reported-by: Colin King <colin.king@canonical.com>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Cc: stable <stable@vger.kernel.org> # 4.13
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Starting from Intel Falcon Ridge the internal connection manager running
on the Thunderbolt host controller has been supporting 4 security
levels. One reason for this is to prevent DMA attacks and only allow
connecting devices the user trusts.
The internal connection manager (ICM) is the preferred way of connecting
Thunderbolt devices over software only implementation typically used on
Macs. The driver communicates with ICM using special Thunderbolt ring 0
(control channel) messages. In order to handle these messages we add
support for the ICM messages to the control channel.
The security levels are as follows:
none - No security, all tunnels are created automatically
user - User needs to approve the device before tunnels are created
secure - User need to approve the device before tunnels are created.
The device is sent a challenge on future connects to be able
to verify it is actually the approved device.
dponly - Only Display Port and USB tunnels can be created and those
are created automatically.
The security levels are typically configurable from the system BIOS and
by default it is set to "user" on many systems.
In this patch each Thunderbolt device will have either one or two new
sysfs attributes: authorized and key. The latter appears for devices
that support secure connect.
In order to identify the device the user can read identication
information, including UUID and name of the device from sysfs and based
on that make a decision to authorize the device. The device is
authorized by simply writing 1 to the "authorized" sysfs attribute. This
is following the USB bus device authorization mechanism. The secure
connect requires an additional challenge step (writing 2 to the
"authorized" attribute) in future connects when the key has already been
stored to the NVM of the device.
Non-ICM systems (before Alpine Ridge) continue to use the existing
functionality and the security level is set to none. For systems with
Alpine Ridge, even on Apple hardware, we will use ICM.
This code is based on the work done by Amir Levy and Michael Jamet.
Signed-off-by: Michael Jamet <michael.jamet@intel.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Yehezkel Bernat <yehezkel.bernat@intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Andreas Noever <andreas.noever@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
If a request times out the response might arrive right after the request
is failed. This response is pushed to the kfifo and next request will
read it instead. Since it most likely will not pass our validation
checks in parse_header() the next request will fail as well, and
response to that request will be pushed to the kfifo, ad infinitum.
We end up in a situation where all requests fail and no devices can be
added anymore until the driver is unloaded and reloaded again.
To overcome this, rework the control channel so that we will have a
queue of outstanding requests. Each request will be handled in turn and
the response is validated against what is expected. Unexpected packets
(for example responses for requests that have been timed out) are
dropped. This model is copied from Greybus implementation with small
changes here and there to get it cope with Thunderbolt control packets.
In addition the configuration packets support sequence number which the
switch is supposed to copy from the request to response. We use this to
drop responses that are already timed out. Taking advantage of the
sequence number, we automatically retry configuration read/write 4 times
before giving up.
Also timeout is not a programming error so there is no need to trigger a
scary backtrace (WARN), instead we just log a warning. After all
Thunderbolt devices are hot-pluggable by definition which means user can
unplug a device any time and that is totally acceptable.
With this change there is no need to take the global domain lock when
sending configuration packets anymore. This is useful when we add
support for cross-domain (XDomain) communication later on.
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Yehezkel Bernat <yehezkel.bernat@intel.com>
Reviewed-by: Michael Jamet <michael.jamet@intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Andreas Noever <andreas.noever@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Currently the control channel (ctl.c) handles the one supported
notification (PLUG_EVENT) and sends back ACK accordingly. However, we
are going to add support for the internal connection manager (ICM) that
needs to handle a different notifications. So instead of dealing
everything in the control channel, we change the callback to take an
arbitrary thunderbolt packet and convert the native connection manager
to handle the event itself.
In addition we only push replies we know of to the response FIFO.
Everything else is treated as notification (or request) and is expected
to be dealt by the connection manager implementation.
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Yehezkel Bernat <yehezkel.bernat@intel.com>
Reviewed-by: Michael Jamet <michael.jamet@intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Andreas Noever <andreas.noever@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We will be using this function in files introduced in subsequent
patches. While there the function is renamed to tb_cfg_make_header()
following tb_cfg_get_route().
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Yehezkel Bernat <yehezkel.bernat@intel.com>
Reviewed-by: Michael Jamet <michael.jamet@intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Andreas Noever <andreas.noever@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We are going to use it when we change the connection manager to handle
events itself. Also rename it to follow naming convention used in
functions exposed in ctl.h.
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Yehezkel Bernat <yehezkel.bernat@intel.com>
Reviewed-by: Michael Jamet <michael.jamet@intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Andreas Noever <andreas.noever@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We will be forwarding notifications received from the control channel to
the connection manager implementations. This way they can decide what to
do if anything when a notification is received.
To be able to use control channel messages from other files, move them
to tb_msgs.h.
No functional changes intended.
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Yehezkel Bernat <yehezkel.bernat@intel.com>
Reviewed-by: Michael Jamet <michael.jamet@intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Andreas Noever <andreas.noever@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Following the usual pattern used in many places, we allow passing NULL
pointer to tb_ctl_free(). Then the user can call the function regardless
if it has allocated control channel or not making the code bit simpler.
Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Andreas Noever <andreas.noever@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Intel Thunderbolt controllers support up to 16 MSI-X vectors. Using
MSI-X is preferred over MSI or legacy interrupt and may bring additional
performance because there is no need to check the status registers which
interrupt was triggered.
While there we convert comments in structs tb_ring and tb_nhi to follow
kernel-doc format more closely.
This code is based on the work done by Amir Levy and Michael Jamet.
Signed-off-by: Michael Jamet <michael.jamet@intel.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Yehezkel Bernat <yehezkel.bernat@intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Andreas Noever <andreas.noever@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
These functions should not (and do not) modify the argument in any way
so make it const.
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Yehezkel Bernat <yehezkel.bernat@intel.com>
Reviewed-by: Michael Jamet <michael.jamet@intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Andreas Noever <andreas.noever@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Fix typo in tb_cfg_print_error() message. Fix bytecount in struct
tb_drom_entry_port comment. Replace magic number in tb_switch_alloc().
Rename tb_sw_set_unpplugged() and TB_CAL_IECS to fix typos.
[bhelgaas: no functional change intended]
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Andreas Noever <andreas.noever@gmail.com>
Thunderbolt packets are big endian. Cast pkg->buffer to __be32* when
accessing the checksum.
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Andreas Noever <andreas.noever@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The function returns a pointer. Hence return NULL instead of 0.
Signed-off-by: Sachin Kamat <sachin.kamat@samsung.com>
Acked-by: Andreas Noever <andreas.noever@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Fix issues observed with the Startech docking station:
Fix the type of the route parameter in tb_ctl_rx. It should be u64 and not
u8 (which only worked for short routes).
A thunderbolt cable contains two lanes. If both endpoints support it a
connection will be established on both lanes. Previously we tried to
scan below both "dual link ports". Use the information extracted from
the drom to only scan behind ports with lane_nr == 0.
Endpoints with more complex thunderbolt controllers have some of their
ports disabled (for example the NHI port or one of the HDMI/DP ports).
Accessing them results in an error so we now ignore ports which are
marked as disabled in the drom.
Signed-off-by: Andreas Noever <andreas.noever@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Thunderbolt devices are configured by reading/writing into their
configuration space (similar to pci). This is done by sending packets
through the NHI (native host interface) onto the control channel.
This patch handles the low level packet based protocol and exposes
higher level operations like tb_cfg_read/tb_cfg_write.
Signed-off-by: Andreas Noever <andreas.noever@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
