thunderbolt: Constify the struct device_type usage

Since commit aed65af1cc2f ("drivers: make device_type const"), the driver
core can properly handle constant struct device_type. Move the
tb_domain_type, tb_retimer_type, tb_switch_type, usb4_port_device_type,
tb_service_type and tb_xdomain_type variables to be constant structures as
well, placing it into read-only memory which can not be modified at
runtime.

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ricardo B. Marliere <ricardo@marliere.net>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>

thunderbolt: make tb_bus_type const

Now that the driver core can properly handle constant struct bus_type,
move the tb_bus_type variable to be a constant structure as well,
placing it into read-only memory which can not be modified at runtime.

Cc: Andreas Noever <andreas.noever@gmail.com>
Cc: Michael Jamet <michael.jamet@intel.com>
Cc: Yehezkel Bernat <YehezkelShB@gmail.com>
Cc: <linux-usb@vger.kernel.org>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Link: https://lore.kernel.org/r/2023121904-utopia-broadcast-06d1@gregkh
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

thunderbolt: Fix typo in enum tb_link_width kernel-doc

Typo trasmitters -> transmitters.

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

thunderbolt: Add support for USB4 v2 80 Gb/s link

USB4 v2 bumps the per-lane speed up to 40 Gb/s. Also the lanes are
always bonded which gives 80 Gb/s symmetric link (and 120/40 Gb/s
asymmetric). This updates the speed and width of routers and XDomain
connections to support the Gen 4 link. For now we keep the link as is
even if it is already asymmetric.

While there make tb_port_set_link_width() static.

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

thunderbolt: Show link type for XDomain connections too

Following what we do for routers already, extend this to XDomain
connections as well. This will show in sysfs whether the link is in USB4
or Thunderbolt mode.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

thunderbolt: Add support for XDomain lane bonding

The USB4 Inter-Domain Service specification defines a protocol that can
be used to establish lane bonding between two USB4 domains (hosts). So
far we have not implemented it because the host controller DMA was not
fast enough to be able to go over 20 Gbits/s even if lanes were bonded.
However, starting from Intel Alder Lake CPUs the DMA can go over
20 Gbits/s so now it makes more sense to add this support to the driver.

Because both ends need to negotiate the bonding we add a simple state
machine that tracks the connection state and does the necessary steps
described by the USB4 Inter-Domain Service specification. We only
establish lane bonding when both sides of the link support it. Otherwise
we default to use the single lane. Also this is only done when software
connection manager is used. On systems with firmware based connection
manager, it handles the high-speed tunneling so bonding lanes is
specific to the implementation (Intel firmware based connection manager
does not support lane bonding).

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

thunderbolt: Make iommu_dma_protection more accurate

Between me trying to get rid of iommu_present() and Mario wanting to
support the AMD equivalent of DMAR_PLATFORM_OPT_IN, scrutiny has shown
that the iommu_dma_protection attribute is being far too optimistic.
Even if an IOMMU might be present for some PCI segment in the system,
that doesn't necessarily mean it provides translation for the device(s)
we care about. Furthermore, all that DMAR_PLATFORM_OPT_IN really does
is tell us that memory was protected before the kernel was loaded, and
prevent the user from disabling the intel-iommu driver entirely. While
that lets us assume kernel integrity, what matters for actual runtime
DMA protection is whether we trust individual devices, based on the
"external facing" property that we expect firmware to describe for
Thunderbolt ports.

It's proven challenging to determine the appropriate ports accurately
given the variety of possible topologies, so while still not getting a
perfect answer, by putting enough faith in firmware we can at least get
a good bit closer. If we can see that any device near a Thunderbolt NHI
has all the requisites for Kernel DMA Protection, chances are that it
*is* a relevant port, but moreover that implies that firmware is playing
the game overall, so we'll use that to assume that all Thunderbolt ports
should be correctly marked and thus will end up fully protected.

CC: Mario Limonciello <mario.limonciello@amd.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Link: https://lore.kernel.org/r/b153f208bc9eafab5105bad0358b77366509d2d4.1650878781.git.robin.murphy@arm.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>

thunderbolt: Add vendor specific NHI quirk for auto-clearing interrupt status

Introduce nhi_check_quirks() routine to handle any vendor specific quirks
to manage a hardware specific implementation.

On Intel hardware the USB4 controller supports clearing the interrupt
status register automatically right after it is being issued. For this
reason add a new quirk that does that on all Intel hardware.

Signed-off-by: Basavaraj Natikar <Basavaraj.Natikar@amd.com>
Signed-off-by: Sanjay R Mehta <sanju.mehta@amd.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>

thunderbolt: Allow multiple DMA tunnels over a single XDomain connection

Currently we have had an artificial limitation of a single DMA tunnel
per XDomain connection. However, hardware wise there is no such limit
and software based connection manager can take advantage of all the DMA
rings available on the host to establish tunnels.

For this reason make the tb_xdomain_[enable|disable]_paths() to take the
DMA ring and HopID as parameter instead of storing them in the struct
tb_xdomain. We also add API functions to allocate input and output
HopIDs of the XDomain connection that the service drivers can use
instead of hard-coding.

Also convert the two existing service drivers over to this API.

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

thunderbolt: Add support for maxhopid XDomain property

USB4 inter-domain spec mandates that the compatible hosts expose a new
property "maxhopid" that tells the connection manager on the other side
what is the maximum supported input HopID over the connection. Since
this is depend on the lane adapter the cable is connected it needs to be
filled in dynamically.

For this reason we take a copy of the global properties and fill then
for each XDomain connection upon first connect, and then keep updating
it if the generation changes as services are being added/removed. We
also take advantage of this copy to fill in the hostname.

We also expose this maxhopid as an attribute under each XDomain device.

While there drop kernel-doc entry for property_lock which seems to be
left there when the structure was originally introduced.

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

thunderbolt: Add tb_property_copy_dir()

This function takes a deep copy of the properties. We need this in order
to support more dynamic properties per XDomain connection as required by
the USB4 inter-domain service spec.

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

thunderbolt: Do not re-establish XDomain DMA paths automatically

This step is actually not needed. The service drivers themselves will
handle this once they have negotiated the service up and running again
with the remote side. Also dropping this makes it easier to add support
for multiple DMA tunnels over a single XDomain connection.

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

thunderbolt: Add support for PCIe tunneling disabled (SL5)

Recent Intel Thunderbolt firmware connection manager has support for
another security level, SL5, that disables PCIe tunneling. This option
can be turned on from the BIOS.

When this is set the driver exposes a new security level "nopcie" to the
userspace and hides the authorized attribute under connected devices.

While there we also hide it when "dponly" security level is enabled
since it is not really usable in that case anyway.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Yehezkel Bernat <YehezkelShB@gmail.com>

thunderbolt: Add support for end-to-end flow control

USB4 spec defines end-to-end (E2E) flow control that can be used between
hosts to prevent overflow of a RX ring. We previously had this partially
implemented but that code was removed with commit 53f13319d131
("thunderbolt: Get rid of E2E workaround") with the idea that we add it
back properly if there ever is need. Now that we are going to add DMA
traffic test driver (in subsequent patches) this can be useful.

For this reason we modify tb_ring_alloc_rx/tx() so that they accept
RING_FLAG_E2E and configure the hardware ring accordingly. The RX side
also requires passing TX HopID (e2e_tx_hop) used in the credit grant
packets.

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>

thunderbolt: Create debugfs directory automatically for services

This allows service drivers to use it as parent directory if they need
to add their own debugfs entries.

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>

thunderbolt: Add functions for enabling and disabling lane bonding on XDomain

These can be used by service drivers to enable and disable lane bonding
as needed.

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>

thunderbolt: Add link_speed and link_width to XDomain

Link speed and link width are needed for checking expected values in
case of using a loopback service.

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>

thunderbolt: Get rid of E2E workaround

The end-to-end (E2E) workaround is needed for Falcon Ridge (TBT 2)
controller when E2E is enabled for both ends of the host-to-host
connection. However, we never supported full E2E in the first place so
this code is not necessary at the moment. Further this allows us to use
all available rings for data except ring 0 which is reserved for the
control path.

The complete E2E flow control is explained in the USB4 spec so we may
add it back later if needed but at least the networking driver seems to
work fine without, and the higher level stack, like TCP will retransmit
lost packets anyway.

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

thunderbolt: Replace zero-length array with flexible-array

The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:

struct foo {
int stuff;
struct boo array[];
};

By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.

Also, notice that, dynamic memory allocations won't be affected by
this change:

"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]

sizeof(flexible-array-member) triggers a warning because flexible array
members have incomplete type[1]. There are some instances of code in
which the sizeof operator is being incorrectly/erroneously applied to
zero-length arrays and the result is zero. Such instances may be hiding
some bugs. So, this work (flexible-array member conversions) will also
help to get completely rid of those sorts of issues.

This issue was found with the help of Coccinelle.

[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour")

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>

thunderbolt: Add support for Intel Ice Lake

The Thunderbolt controller is integrated into the Ice Lake CPU itself
and requires special flows to power it on and off using force power bit
in NHI VSEC registers. Runtime PM (RTD3) and Sx flows also differ from
the discrete solutions. Now the firmware notifies the driver whether
RTD3 entry or exit are possible. The driver is responsible of sending
Go2Sx command through link controller mailbox when system enters Sx
states (suspend-to-mem/disk). Rest of the ICM firwmare flows follow
Titan Ridge.

Signed-off-by: Raanan Avargil <raanan.avargil@intel.com>
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>

thunderbolt: Add XDomain UUID exchange support

Currently ICM has been handling XDomain UUID exchange so there was no
need to have it in the driver yet. However, since now we are going to
add the same capabilities to the software connection manager it needs to
be handled properly.

For this reason modify the driver XDomain protocol handling so that if
the remote domain UUID is not filled in the core will query it first and
only then start the normal property exchange flow.

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

thunderbolt: Convert rest of the driver files to use SPDX identifier

This gets rid of the licence boilerplate duplicated in each file. While
there fix doubled space in domain.c author line.

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>

thunderbolt: Introduce USB only (SL4) security level

This new security level works so that it creates one PCIe tunnel to the
connected Thunderbolt dock, removing PCIe links downstream of the dock.
This leaves only the internal USB controller visible.

Display Port tunnels are created normally.

While there make sure security sysfs attribute returns "unknown" for any
future security level.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>

thunderbolt: Add support for preboot ACL

Preboot ACL is a mechanism that allows connecting Thunderbolt devices
boot time in more secure way than the legacy Thunderbolt boot support.
As with the legacy boot option, this also needs to be enabled from the
BIOS before booting is allowed. Difference to the legacy mode is that
the userspace software explicitly adds device UUIDs by sending a special
message to the ICM firmware. Only the devices listed in the boot ACL are
connected automatically during the boot. This works in both "user" and
"secure" security levels.

We implement this in Linux by exposing a new sysfs attribute (boot_acl)
below each Thunderbolt domain. The userspace software can then update
the full list as needed.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>

thunderbolt: Add tb_xdomain_find_by_route()

This is needed by the new ICM interface to find xdomains by route string
instead of link and depth.

While there update existing tb_xdomain_find_* functions to use
tb_xdomain_get() instead of open-coding the same.

Signed-off-by: Radion Mirchevsky <radion.mirchevsky@intel.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>

thunderbolt: Add function to retrieve DMA device for the ring

This is needed when Thunderbolt service drivers need to DMA map memory
before it is passed down to the ring.

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>

thunderbolt: Add polling mode for rings

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>

thunderbolt: Use spinlock in NHI serialization

This is needed because ring polling functionality can be called from
atomic contexts when networking and other high-speed traffic is
transferred over a Thunderbolt cable.

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>

thunderbolt: Use spinlock in ring serialization

This makes it possible to enqueue frames also from atomic context which
is needed for example, when networking packets are sent over a
Thunderbolt cable.

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>

thunderbolt: Move ring descriptor flags to thunderbolt.h

A Thunderbolt service driver might need to check if there was an error
with the descriptor when in frame mode. We also add two Rx specific
error flags RING_DESC_CRC_ERROR and RING_DESC_BUFFER_OVERRUN.

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>

thunderbolt: Export ring handling functions to modules

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>

thunderbolt: Add support for XDomain discovery protocol

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>

thunderbolt: Move tb_switch_phy_port_from_link() to thunderbolt.h

A Thunderbolt service might need to find the physical port from a link
the cable is connected to. For instance networking driver uses this
information to generate MAC address according the Apple ThunderboltIP
protocol.

Move this function to thunderbolt.h and rename it to
tb_phy_port_from_link() to reflect the fact that it does not take switch
as parameter.

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>

thunderbolt: Move thunderbolt domain structure to thunderbolt.h

These are needed by Thunderbolt services so move them to thunderbolt.h
to make sure they are available outside of drivers/thunderbolt.

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>

thunderbolt: Move enum tb_cfg_pkg_type to thunderbolt.h

These will be needed by Thunderbolt services when sending and receiving
XDomain control messages. While there change TB_CFG_PKG_PREPARE_TO_SLEEP
value to be decimal in order to be consistent with other members.

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>

thunderbolt: Add support for XDomain properties

Thunderbolt XDomain discovery protocol uses directories which contain
properties and other directories to exchange information about what
capabilities the remote host supports. This also includes identification
information like device ID and name.

This adds support for parsing and formatting these properties and
establishes an API drivers can use in addition to the core Thunderbolt
driver. This API is exposed in a new header: include/linux/thunderbolt.h.

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>