thunderbolt: Make tb_switch_reset() support Thunderbolt 2, 3 and USB4 routers

Currently tb_switch_reset() only did something for Thunderbolt 1
devices. Expand this to support all generations, including USB4, and
both host and device routers.

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

thunderbolt: Introduce tb_port_reset()

Introduce a function that issues Downstream Port Reset to a USB4 port.
This supports Thunderbolt 2, 3 and USB4 routers.

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

thunderbolt: Fix setting the CNS bit in ROUTER_CS_5

The bit 23, CM TBT3 Not Supported (CNS), in ROUTER_CS_5 indicates
whether a USB4 Connection Manager is TBT3-Compatible and should be:
0b for TBT3-Compatible
1b for Not TBT3-Compatible

Fixes: b04079837b20 ("thunderbolt: Add initial support for USB4")
Cc: stable@vger.kernel.org
Signed-off-by: Mohammad Rahimi <rahimi.mhmmd@gmail.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>

thunderbolt: Add support for asymmetric link

USB4 v2 spec defines a Gen 4 link that can operate as an aggregated
symmetric (80/80G) or asymmetric (120/40G). When the link is asymmetric,
the USB4 port on one side of the link operates with three TX lanes and
one RX lane, while the USB4 port on the opposite side of the link
operates with three RX lanes and one TX lane.

Add support for the asymmetric link and provide functions that can be
used to transition the link to asymmetric and back.

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>

thunderbolt: Set path power management packet support bit for USB4 v2 routers

USB4 v2 spec allows USB4 links that are part of a pass through tunnel
(such as DisplayPort and USB 3.x Gen T) to enter lower CL states, which
provide better power management. For this USB4 v2 routers in their path
config space of lane 0 adapter include a new bit PMPS (PM packet
support) that needs to be set.

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

thunderbolt: Fix typo of HPD bit for Hot Plug Detect

Fix typo of HPD bit stands for Hot Plug Detect.

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

thunderbolt: Get rid of usb4_usb3_port_actual_link_rate()

It turns out there is no need to use the actual link rate when
reclaiming bandwidth for USB 3.x. The reason is that we use consumed
bandwidth which is coming from xHCI when releasing bandwidth (for
example for DisplayPort tunneling) and this can be anything between
1000 Mb/s to maximum, so when reclaiming we can just bump it up back to
maximum instead of actual link rate (which is always <= maximum).

This allows us to get rid of couple of unnecessary lines of code.

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

thunderbolt: Add DisplayPort 2.x tunneling support

This adds support for the UHBR (Ultra High Bit Rate) bandwidths
introduced with DisplayPort 2.0 (and refined in 2.1). These can go up to
80 Gbit/s and their support is represent in additional bits in the DP IN
capability.

This updates the DisplayPort tunneling to support these new rates too.

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

thunderbolt: Add support for enhanced uni-directional TMU mode

This is new TMU mode introduced with the USB4 v2. This mode is simpler
than the existing ones and allows all CL states as well. Enable this for
all links where both side routers are v2 and keep the existing
functionality for the v1 and earlier links.

Currently only support the MedRes rate. We can add the HiFi rate later
too if it turns out to be useful.

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

thunderbolt: Enable USB4 v2 PCIe TLP/DLLP extended encapsulation

USB4 v2 spec introduces modified encapsulation of PCIe TLP and DLLP
packets. This improves the PCIe tunneled traffic usage by reducing
overhead. Enable this if both sides of the link support it.

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

thunderbolt: Announce USB4 v2 connection manager support

Program the CMUV (Connection Manager USB4 Version) field for USB4 v2 and
v1 routers according to the spec.

Signed-off-by: Gil Fine <gil.fine@intel.com>
Signed-off-by: Mika Westerberg <mika.westerberg@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: Identify USB4 v2 routers

Add a new function usb4_switch_version() that can be used to figure out
the spec version of the router and make tb_switch_is_usb4() to use it as
well. Update the uevent accordingly.

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

thunderbolt: Add functions to support DisplayPort bandwidth allocation mode

USB4 spec defines an additional feature that DP IN adapters can
implement (alongside with the graphics DPCD register set) to support
more dynamic bandwidth management for DisplayPort tunnels. For the
connection manager the communication happens through the DP IN adapter
using a set of registers in the adapter config space allocated for this.
Add functions that export this functionality for the rest of the driver.

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

thunderbolt: Take CL states into account when waiting for link to come up

If CL states are enabled for the link it may be in these states too when
reading the lane adapter state but it will enter CL0 as soon as there is
traffic in the high-speed lanes. Upon discovery we want to make sure
that is accounted as the link being up, otherwise we end up tearing down
the topology with no good reason.

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

thunderbolt: Add wake on connect/disconnect on USB4 ports

Wake on connect/disconnect is only supported while runtime suspend for
now, which is obviously necessary. It is also not inherently desired for
the system to wakeup on Thunderbolt/USB4 hot plug events. However, we
can still make user in control of waking up the system in the events of
hot plug/unplug.

This patch adds 'wakeup' attribute under 'usb4_portX/power' sysfs
attribute and only enables wakes on connect/disconnect to the respective
port when 'wakeup' is set to 'enabled'. The attribute is set to
'disabled' by default.

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

thunderbolt: Explicitly enable lane adapter hotplug events at startup

Software that has run before the USB4 CM in Linux runs may have disabled
hotplug events for a given lane adapter.

Other CMs such as that one distributed with Windows 11 will enable hotplug
events. Do the same thing in the Linux CM which fixes hotplug events on
"AMD Pink Sardine".

Cc: stable@vger.kernel.org
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>

thunderbolt: Add helper to check if CL states are enabled on port

We will need this when enabling lane margining support.

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

thunderbolt: Pass CL state bitmask to tb_port_clx_supported()

Instead of testing just a single CL state we can pass a bitmask of
states to check. This makes it simpler for callers of the function.

We also add a check for CL2 even though not fully supported by the
driver yet.

Suggested-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>

thunderbolt: Add CL1 support for USB4 and Titan Ridge routers

In this patch we add support for a second low power state of the link: CL1.
Low power states (called collectively CLx) are used to reduce
transmitter and receiver power when a high-speed lane is idle.
We enable it, if both sides of the link support it,
and only for the first hop router (i.e. the first device that connected
to the host router). This is needed for better thermal management.

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

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: Rename EEPROM handling bits to match USB4 spec

The structure `tb_eeprom_ctl` is used to show the bits accessed when
reading/writing EEPROM.

As this structure is specified in the USB4 spec as `VSC_CS_4` update
the names and use of members to match the specification. This should not
change anything functionally.

Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>

thunderbolt: Clarify register definitions for `tb_cap_plug_events`

The USB4 1.0 specification outlines the `cap_plug_events` structure as
`VSC_CS_1`. This shows that 4 bits of `VSC_CS_1` are TBT3 compatible in
USB4, but TBT3 controllers also support disabling XHCI.

Update the names and comments to more closely match the specification.
This should not change anything functionally.

Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>

thunderbolt: Add internal xHCI connect flows for Thunderbolt 3 devices

Both Alpine Ridge and Titan Ridge require special flows in order to
activate the internal xHCI controller when there is USB device connected
to the downstream type-C port. This implements the missing flows for
both.

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

thunderbolt: Disable LTTPR on Intel Titan Ridge

Intel Titan Ridge does not disable AUX timers when it gets SET_CONFIG
with SET_LTTPR_MODE set which makes DP tunneling to fail. For this
reason disable LTTPR on Titan Ridge device side.

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

thunderbolt: Enable CL0s for Intel Titan Ridge

Low power link states (called collectively CLx) are used to reduce
transmitter and receiver power when a high-speed lane is idle. The
simplest one being called CL0s. Follow what we already do for USB4
device routers and enable CL0s for Intel Titan Ridge device router too.
This allows better thermal management.

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

thunderbolt: Rename Intel TB_VSE_CAP_IECS capability

Rename the VSC capability: TB_VSE_CAP_IECS to TB_VSE_CAP_CP_LP to follow
the Intel devices namings as appear in the datasheet. This capability
is used for controlling CLx (Low Power states of the link).

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

thunderbolt: Implement TMU time disruption for Intel Titan Ridge

Intel Titan Ridge based routers have slightly different flow for time
disruption than USB4 compliant routers. This makes it work on Titan
Ridge too. Needed to enable link low power states on Titan Ridge.

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

thunderbolt: Add CL0s support for USB4 routers

In this patch we add enabling of CL0s - a low power state of the link.
Low power states (called collectively CLx) are used to reduce
transmitter and receiver power when a high-speed lane is idle. For now,
we add support only for first low power state: CL0s. We enable it, if
both sides of the link support it, and only for the first hop router.
(i.e. the first device that connected to the host router). This is
needed for better thermal management.

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

thunderbolt: Add TMU uni-directional mode

Up until Titan Ridge (Thunderbolt 3) device routers only supported
bi-directional mode. In this patch we add to TMU a uni-directional mode.
The uni-directional mode is needed for enabling of low power state of
the link (CLx).

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

thunderbolt: Read router preferred credit allocation information

USB4 routers must expose their preferred credit (buffer) allocation
information through router operation. This information tells the
connection manager how the router prefers its buffers to be allocated to
get the expected bandwidth for the supported protocols.

Read this information and store it as part of struct tb_switch for each
USB4 router.

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

thunderbolt: Add wake from DisplayPort

Latest USB4 spec added a new wake bit for DisplayPort so add this to the
driver when runtime suspending. This way wake up the domain when a new
monitor is plugged in to any of the device routers.

Also do the same for pre-USB4 devices through the link controller
registers as documented in chapter 13 of the USB4 spec.

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

thunderbolt: Start lane initialization after sleep

USB4 spec says that for TBT3 compatible device routers the connection
manager needs to set SLI (Start Lane Initialization) to get the lanes
that were not connected back to functional state after sleep. Same needs
to be done if the link was XDomain.

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

thunderbolt: Move constants for USB4 router operations to tb_regs.h

We are going to use these in subsequent patch so make them available
outside of usb4.c.

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

thunderbolt: Perform USB4 router NVM upgrade in two phases

The currect code expects that the router returns back the status of the
NVM authentication immediately. When tested against a real USB4 device
what happens is that the router is reset and only after that the result
is updated in the ROUTER_CS_26 register status field. This also seems to
align better what the spec suggests.

For this reason do the same what we already do with the Thunderbolt 3
devices and perform the NVM upgrade in two phases. First start the
NVM_AUTH router operation and once the router is added back after the
reset read the status in ROUTER_CS_26 and expose it to the userspace
accordingly.

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

thunderbolt: Add debugfs interface

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>

thunderbolt: Move struct tb_cap_any to tb_regs.h

This structure will be needed by the debugfs implementation so make it
available outside of cap.c.

While there add kernel-doc comments to the structure.

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

thunderbolt: Enable wakes from system suspend

In order for the router and the whole domain to wake up from system
suspend states we need to enable wakes for the connected routers. For
device routers we enable wakes from PCIe and USB 3.x. This allows
devices such as keyboards connected to USB 3.x hub that is tunneled to
wake the system up as expected. For all routers we enabled wake on USB4
for each connected ports. This is used to propagate the wake from router
to another.

Do the same for legacy routers through link controller vendor specific
registers as documented in USB4 spec chapter 13.

While there correct kernel-doc of usb4_switch_set_sleep() -- it does not
enable wakes instead there is a separate function (usb4_switch_set_wake())
that does.

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

thunderbolt: Disable lane 1 for XDomain connection

USB4 spec mandates that the lane 1 should be disabled if lanes are not
bonded. For host-to-host connections (XDomain) we don't support lane
bonding so in order to be compatible with the spec, disable lane 1 when
another host is connected.

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

thunderbolt: Configure port for XDomain

When the port is connected to another host it should be marked as such
in the USB4 port capability. This information is used by the router
during sleep and wakeup.

Also do the same for legacy switches via link controller vendor specific
registers.

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

thunderbolt: Add support for authenticate on disconnect

Some external devices can support completing thunderbolt authentication
when they are unplugged. For this to work though, the link controller must
remain operational.

The only device known to support this right now is the Dell WD19TB, so add
a quirk for this.

Signed-off-by: Mario Limonciello <mario.limonciello@dell.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>

thunderbolt: Implement USB4 port sideband operations for retimer access

USB4 spec specifies standard set of sideband operations that are send
over the low speed link to access either retimers on the link or the
link parter (the other router). The USB4 retimer spec extends these and
adds operations for retimer NVM upgrade.

This implements the retimer access and NVM upgrade USB4 port sideband
operations which we need for retimer support in the patch that follows.

Signed-off-by: Rajmohan Mani <rajmohan.mani@intel.com>
Co-developed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>

thunderbolt: Implement USB3 bandwidth negotiation routines

Each host router USB3 downstream adapter has a set of registers that are
used to negotiate bandwidth between the connection manager and the
internal xHCI controller. These registers allow dynamic bandwidth
management for USB3 isochronous traffic based on what is actually
consumed vs. allocated at any given time.

Implement these USB3 bandwidth negotiation routines to allow the
software connection manager take advantage of these.

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

thunderbolt: Do not tunnel USB3 if link is not USB4

USB3 tunneling is possible only over USB4 link so don't create USB3
tunnels if that's not the case.

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

thunderbolt: Add support for USB 3.x tunnels

USB4 added a capability to tunnel USB 3.x protocol over the USB4
fabric. USB4 device routers may include integrated SuperSpeed HUB or a
function or both. USB tunneling follows PCIe so that the tunnel is
created between the parent and the child router from USB3 downstream
adapter port to USB3 upstream adapter port over a single USB4 link.

This adds support for USB 3.x tunneling and also capability to discover
existing USB 3.x tunnels (for example created by connection manager in
boot firmware).

Signed-off-by: Rajmohan Mani <rajmohan.mani@intel.com>
Co-developed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Link: https://lore.kernel.org/r/20191217123345.31850-9-mika.westerberg@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

thunderbolt: Add support for Time Management Unit

Time Management Unit (TMU) is included in each USB4 router. It is used
to synchronize time across the USB4 fabric. By default when USB4 router
is plugged to the domain, its TMU is turned off. This differs from
Thunderbolt (1, 2 and 3) devices whose TMU is by default configured to
bi-directional HiFi mode. Since time synchronization is needed for
proper Display Port tunneling this means we need to configure the TMU on
USB4 compliant devices.

The USB4 spec allows some flexibility on how the TMU can be configured.
This makes it possible to enable link power management states (CLx) in
certain topologies, where for example DP tunneling is not used. TMU can
also be re-configured dynamicaly depending on types of tunnels created
over the USB4 fabric.

In this patch we simply configure the TMU to be in bi-directional HiFi
mode. This way we can tunnel any kind of traffic without need to perform
complex steps to re-configure the domain dynamically. We can add more
fine-grained TMU configuration later on when we start enabling CLx
states.

Signed-off-by: Rajmohan Mani <rajmohan.mani@intel.com>
Co-developed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Link: https://lore.kernel.org/r/20191217123345.31850-8-mika.westerberg@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

thunderbolt: Add initial support for USB4

USB4 is the public specification based on Thunderbolt 3 protocol. There
are some differences in register layouts and flows. In addition to PCIe
and DP tunneling, USB4 supports tunneling of USB 3.x. USB4 is also
backward compatible with Thunderbolt 3 (and older generations but the
spec only talks about 3rd generation). USB4 compliant devices can be
identified by checking USB4 version field in router configuration space.

This patch adds initial support for USB4 compliant hosts and devices
which enables following features provided by the existing functionality
in the driver:

- PCIe tunneling
- Display Port tunneling
- Host and device NVM firmware upgrade
- P2P networking

This brings the USB4 support to the same level that we already have for
Thunderbolt 1, 2 and 3 devices.

Note the spec talks about host and device "routers" but in the driver we
still use term "switch" in most places. Both can be used interchangeably.

Co-developed-by: Rajmohan Mani <rajmohan.mani@intel.com>
Signed-off-by: Rajmohan Mani <rajmohan.mani@intel.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Link: https://lore.kernel.org/r/20191217123345.31850-5-mika.westerberg@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

thunderbolt: Add bandwidth management for Display Port tunnels

Titan Ridge supports Display Port 1.4 which adds HBR3 (High Bit Rate)
rates that may be up to 8.1 Gb/s over 4 lanes. This translates to
effective data bandwidth of 25.92 Gb/s (as 8/10 encoding is removed by
the DP adapters when going over Thunderbolt fabric). If another high
rate monitor is connected we may need to reduce the bandwidth it
consumes so that it fits into the total 40 Gb/s available on the
Thunderbolt fabric.

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

thunderbolt: Add Display Port adapter pairing and resource management

To perform proper Display Port tunneling for Thunderbolt 3 devices we
need to allocate DP resources for DP IN port before they can be used.
The reason for this is that the user can also connect a monitor directly
to the Type-C ports in which case the Thunderbolt controller acts as
re-driver for Display Port (no tunneling takes place) taking the DP
sinks away from the connection manager. This allocation is done using
special sink allocation registers available through the link controller.

We can pair DP IN to DP OUT only if

* DP IN has sink allocated via link controller
* DP OUT port receives hotplug event

For DP IN adapters (only for the host router) we first query whether
there is DP resource available (it may be the previous instance of the
driver for example already allocated it) and if it is we add it to the
list. We then update the list when after each plug/unplug event to a DP
IN/OUT adapter. Each time the list is updated we try to find additional
DP IN <-> DP OUT pairs for tunnel establishment. This strategy also
makes it possible to establish another tunnel in case there are 3
monitors connected and one gets unplugged releasing the DP IN adapter
for the new tunnel.

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

thunderbolt: Add Display Port CM handshake for Titan Ridge devices

Titan Ridge needs an additional connection manager handshake in order to
do proper Display Port tunneling so implement it here.

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

thunderbolt: Add support for lane bonding

Lane bonding allows aggregating two 10/20 Gb/s (depending on the
generation) lanes into a single 20/40 Gb/s bonded link. This allows
sharing the full bandwidth more efficiently. In order to establish lane
bonding we need to check that lane bonding is possible through link
controller and that both ends of the link actually supports 2x widths.
This also means that all the paths should be established through the
primary port so update tb_path_alloc() to handle this as well.

Lane bonding is supported starting from Falcon Ridge (2nd generation)
controllers.

We also expose the current speed and number of lanes under each device
except the host router following similar attribute naming than USB bus.
Expose speed and number of lanes for both directions to allow possibility
of asymmetric link in the future.

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

thunderbolt: Convert DP adapter register names to follow the USB4 spec

Now that USB4 spec has names for these DP adapter registers we can use
them instead. This makes it easier to match certain register to the spec.

No functional changes.

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

thunderbolt: Convert PCIe adapter register names to follow the USB4 spec

Now that USB4 spec has names for these PCIe adapter registers we can use
them instead. This makes it easier to match certain register to the spec.

No functional changes.

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

thunderbolt: Convert basic adapter register names to follow the USB4 spec

Now that USB4 spec has names for these basic registers we can use them
instead. This makes it easier to match certain register to the spec.

No functional changes.

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

thunderbolt: Add support for DMA tunnels

In addition to PCIe and Display Port tunnels it is also possible to
create tunnels that forward DMA traffic from the host interface adapter
(NHI) to a NULL port that is connected to another domain through a
Thunderbolt cable. These tunnels can be used to carry software messages
such as networking packets.

To support this we introduce another tunnel type (TB_TUNNEL_DMA) that
supports paths from NHI to NULL port and back.

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

thunderbolt: Add support for Display Port tunnels

Display Port tunnels are somewhat more complex than PCIe tunnels as it
requires 3 tunnels (AUX Rx/Tx and Video). In addition we are not
supposed to create the tunnels immediately when a DP OUT is enumerated.
Instead we need to wait until we get hotplug event to that adapter port
or check if the port has HPD set before tunnels can be established. This
adds Display Port tunneling support to the software connection manager.

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

thunderbolt: Rework NFC credits handling

NFC (non flow control) credits is actually 20-bit field so update
tb_port_add_nfc_credits() to handle this properly. This allows us to set
NFC credits for Display Port path in subsequent patches.

Also make sure the function does not update the hardware if the
underlying switch is already unplugged.

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

thunderbolt: Generalize tunnel creation functionality

To be able to tunnel non-PCIe traffic, separate tunnel functionality
into generic and PCIe specific parts. Rename struct tb_pci_tunnel to
tb_tunnel, and make it hold an array of paths instead of just two.
Update all the tunneling functions to take this structure as parameter.

We also move tb_pci_port_active() to switch.c (and rename it) where we
will be keeping all port and switch related functions.

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

thunderbolt: Properly disable path

We need to wait until all buffers have been drained before the path can
be considered disabled. Do this for every hop in a path.

This adds another bit field to struct tb_regs_hop even if we are trying
to get rid of them but we can clean them up another day.

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

thunderbolt: Set sleep bit when suspending switch

Thunderbolt 2 devices and beyond link controller needs to be notified
when a switch is going to be suspended by setting bit 31 in LC_SX_CTRL
register. Add this functionality to the software connection manager.

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

thunderbolt: Configure lanes when switch is initialized

Thunderbolt 2 devices and beyond need to have additional bits set in
link controller specific registers. This includes two bits in LC_SX_CTRL
that tell the link controller which lane is connected and whether it is
upstream facing or not.

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

thunderbolt: Move LC specific functionality into a separate file

We will be adding more link controller functionality in subsequent
patches and it does not make sense to keep all that in switch.c, so
separate LC functionality into its own file.

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

thunderbolt: Add Intel as copyright holder

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>

thunderbolt: Fix small typo in variable name

Fixes small variable name typo and the associated
checkpatch spelling warning.

Signed-off-by: Nathan Ciobanu <nathan.d.ciobanu@linux.intel.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

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>

thunderbolt: Rework capability handling

Organization of the capabilities in switches and ports is not so random
after all. Rework the capability handling functionality so that it
follows how capabilities are organized and provide two new functions
(tb_switch_find_vse_cap() and tb_port_find_cap()) which can be used to
extract capabilities for ports and switches. Then convert the current
users over these.

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>

thunderbolt: Fix typos and magic number

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: Add tb_regs.h

Every thunderbolt device consists (logically) of a switch with multiple
ports. Every port contains up to four config regions (HOPS, PORT,
SWITCH, COUNTERS) which are used to configure the device.

The tb_regs.h file contains all known registers and capabilities from
these config regions.

Signed-off-by: Andreas Noever <andreas.noever@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>