Add a new file encapsulating most of the PCI NHI specifics
(intentionally leaving some odd cookies behind to make the layering
simpler). Most notably, separate out nhi_probe() to make it easier to
register other types of NHIs.

Also, fold in Intel Icelake (nhi_ops.c) support to contain all
PCIe-related bits in pci.c.

Signed-off-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>

Introduce USB4STREAM protocol and Linux implementation. This allows two
(or more) hosts to transfer data directly over Thunderbolt/USB4 cable
through a character device without need to go through the network stack.

Any application that supports read(2) and write(2) in some form should
be able to use the device without changes. The data is sent out to the
other side over a tunnel inside Thunderbolt/USB4 fabric. The character
device is called /dev/tbstreamX where X is the minor number starting
from 0.

All stream devices need to be configured first. This is done through
ConfigFS interface. There can be multiple streams at the same time (this
depends on number of DMA rings and available HopIDs) and a single stream
supports traffic in both directions. For example there could be an
application that uses one stream as control channel and another one as
bi-directional data channel.

A real use-case for this is to take a backup as a part of recovery
initramfs tooling (no need to setup networking or have ssh or similar
tooling as part of the initramfs). Say we want to backup the disk of
host1 to host2. First Thunderbolt/USB4 cable is connected between the
hosts (there can be devices in the middle too) then the receiving side
configures the stream:

  host2 # mkdir /sys/kernel/config/thunderbolt/stream/0-1.0
  host2 # mkdir /sys/kernel/config/thunderbolt/stream/0-1.0/backup
  host2 # echo -1 > /sys/kernel/config/thunderbolt/stream/0-1.0/backup/in_hopid
  host2 # echo -1 > /sys/kernel/config/thunderbolt/stream/0-1.0/backup/out_hopid

We use automatic HopID allocation (writing -1 to HopIDs) for simplicity.
From this point forward the /dev/tbstream0 can be used pretty much as
regular file:

  host2 # dd if=/dev/tbstream0 of=/tmp/host1.nvme0n1.backup-$(date +%F) bs=256k

The host that is being backed up then configures the stream accordingly:

  host1 # mkdir /sys/kernel/config/thunderbolt/stream/0-503.0
  host1 # mkdir /sys/kernel/config/thunderbolt/stream/0-503.0/backup

Here we take advantage of the fact that host2 also announces the active
streams through XDomain properties so the name "backup" gives us the
HopIDs. It is also possible to configure them manually in the same way
we did for host2.

Then it is just a matter of copying the data over:

  host1 # dd if=/dev/nvme0n1 of=/dev/tbstream0 bs=256k

Similarly it is possible to transfer parts of the filesystem. For
example copy contents of mydir over to the host2:

  host2 # gunzip < /dev/tbstream0 | tar xf -
  host1 # tar cf - mydir | gzip > /dev/tbstream0

Other end of the spectrum use-case is "borrowing" laptop (host1) camera
to desktop (host2):

  host2 # gst-launch-1.0 filesrc location=/dev/tbstream0 ! jpegdec ! videoconvert ! \
                         autovideosink

  host1 # gst-launch-1.0 v4l2src device=/dev/video0 ! video/x-raw,width=1920,height=1080 ! \
                         jpegenc quality=90 ! filesink location=/dev/tbstream0

Once the streams are no longer needed they can be removed:

  host1 # cd /sys/kernel/config/thunderbolt/stream/
  host1 # rmdir -p 0-503.0/backup

  host2 # cd /sys/kernel/config/thunderbolt/stream
  host2 # rmdir -p 0-1.0/backup

Co-developed-by: Alan Borzeszkowski <alan.borzeszkowski@linux.intel.com>
Signed-off-by: Alan Borzeszkowski <alan.borzeszkowski@linux.intel.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>

This adds ConfigFS support to USB4/Thunderbolt bus. By itself this just
creates the subsystem but it exposes functions that can be used to
register groups under it.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>

Sometimes it is useful to see the traffic happening inside the control
channel, especially when debugging a possible problem. This adds
tracepoints close to the hardware which can be enabled dynamically as
needed using the standard Linux trace events facility.

Signed-off-by: Gil Fine <gil.fine@linux.intel.com>
Co-developed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>

There really don't belong to switch.c so move them into their own file.
As we do this rename the functions to match the conventions used
elsewhere in the driver.

No functional changes.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>

The structleak plugin causes the stack frame size to grow immensely when
used with KUnit:

drivers/thunderbolt/test.c:1529:1: error: the frame size of 1176 bytes is larger than 1024 bytes [-Werror=frame-larger-than=]

Turn it off in this file.

Linus already split up tests in this file, so this change *should* be
redundant now.

Signed-off-by: Brendan Higgins <brendanhiggins@google.com>
Suggested-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

Create devices for each USB4 port. This is needed when we add retimer
access when there is no device connected but may be useful for other
purposes too following what USB subsystem does. This exports a single
attribute "link" that shows the type of the USB4 link (or "none" if
there is no cable connected).

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

This driver allows sending DMA traffic over XDomain connection.
Specifically over a loopback connection using either a Thunderbolt/USB4
cable that is connected back to the host router port, or a special
loopback dongle that has RX and TX lines crossed. This can be useful at
manufacturing floor to check whether Thunderbolt/USB4 ports are
functional.

The driver exposes debugfs directory under the XDomain service that can
be used to configure the driver, start the test and check the results.

If a loopback dongle is used the steps to send and receive 1000 packets
can be done like:

  # modprobe thunderbolt_dma_test
  # echo 1000 > /sys/kernel/debug/thunderbolt/<service_id>/dma_test/packets_to_receive
  # echo 1000 > /sys/kernel/debug/thunderbolt/<service_id>/dma_test/packets_to_send
  # echo 1 > /sys/kernel/debug/thunderbolt/<service_id>/dma_test/test
  # cat /sys/kernel/debug/thunderbolt/<service_id>/dma_test/status

When a cable is connected back to host then there are two Thunderbolt
services, one is configured for receiving (does not matter which one):

  # modprobe thunderbolt_dma_test
  # echo 1000 > /sys/kernel/debug/thunderbolt/<service_a>/dma_test/packets_to_receive
  # echo 1 > /sys/kernel/debug/thunderbolt/<service_a>/dma_test/test

The other one for sending:

  # echo 1000 > /sys/kernel/debug/thunderbolt/<service_b>/dma_test/packets_to_send
  # echo 1 > /sys/kernel/debug/thunderbolt/<service_b>/dma_test/test

Results can be read from both services status attributes.

Signed-off-by: Isaac Hazan <isaac.hazan@intel.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Yehezkel Bernat <YehezkelShB@gmail.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

This adds a bit more build coverage for the tests even though these are
not expected to be enabled by normal users and distros. In order to make
this working we need to open-code kunit_test_suite() and call the
relevant functions directly in the driver init/exit hook.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>

This adds debugfs interface that can be used for debugging possible
issues in hardware/software. It exposes router and adapter config spaces
through files like this:

  /sys/kernel/debug/thunderbolt/<DEVICE>/regs
  /sys/kernel/debug/thunderbolt/<DEVICE>/<PORT1>/regs
  /sys/kernel/debug/thunderbolt/<DEVICE>/<PORT1>/path
  /sys/kernel/debug/thunderbolt/<DEVICE>/<PORT1>/counters
  /sys/kernel/debug/thunderbolt/<DEVICE>/<PORT2>/regs
  /sys/kernel/debug/thunderbolt/<DEVICE>/<PORT2>/path
  /sys/kernel/debug/thunderbolt/<DEVICE>/<PORT2>/counters
  ...

The "regs" is either the router or port configuration space register
dump. The "path" is the port path configuration space and "counters" is
the optional counters configuration space.

These files contains one register per line so it should be easy to use
normal filtering tools to find the registers of interest if needed.

The router and adapter regs file becomes writable when
CONFIG_USB4_DEBUGFS_WRITE is enabled (which is not supposed to be done
in production systems) and in this case the developer can write "offset
value" lines there to modify the hardware directly. For convenience this
also supports the long format the read side produces (but ignores the
additional fields). The counters file can be written even when
CONFIG_USB4_DEBUGFS_WRITE is not enabled and it is only used to clear
the counter values.

Signed-off-by: Gil Fine <gil.fine@intel.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>