linux.git/drivers/thunderbolt/tb.c, branch v5.9

thunderbolt: Add support for on-board retimers

2020-06-22T16:58:32+00:00

USB4 spec specifies standard access to retimers (both on-board and
cable) through USB4 port sideband access. This makes it possible to
upgrade their firmware in the same way than we already do with the
routers.

This enumerates on-board retimers under each USB4 port when the link
comes up and adds them to the bus under the router the retimer belongs
to. Retimers are exposed in sysfs with name like :.
where device is the router the retimer belongs to, port is the USB4 port
the retimer is connected to and index is the retimer index under that
port (starting from 1). This applies to the upstream USB4 port as well
so if there is on-board retimer between the port and the router it is
also added accordingly.

At this time we do not add cable retimers but there is no techincal
restriction to do so in the future if needed. It is not clear whether it
makes sense to upgrade their firmwares and at least Thunderbolt 3 cables
it has not been done outside of lab environments.

The sysfs interface is made to follow the router NVM upgrade to make it
easy to extend the existing userspace (fwupd) to handle these as well.

Signed-off-by: Kranthi Kuntala 
Co-developed-by: Mika Westerberg 
Signed-off-by: Mika Westerberg

thunderbolt: Add USB3 bandwidth management

2020-06-22T16:58:20+00:00

USB3 supports both isochronous and non-isochronous traffic. The former
requires guaranteed bandwidth and can take up to 90% of the total
bandwidth. With USB4 USB3 is tunneled over USB4 fabric which means that
we need to make sure there is enough bandwidth allocated for the USB3
tunnels in addition to DisplayPort tunnels.

Whereas DisplayPort bandwidth management is static and done before the
DP tunnel is established, the USB3 bandwidth management is dynamic and
allows increasing and decreasing the allocated bandwidth according to
what is currently consumed. This is done through host router USB3
downstream adapter registers.

This adds USB3 bandwidth management to the software connection manager
so that we always try to allocate maximum bandwidth for DP tunnels and
what is left is allocated for USB3.

Signed-off-by: Mika Westerberg

thunderbolt: Report consumed bandwidth in both directions

2020-06-22T16:58:20+00:00

Whereas DisplayPort bandwidth is consumed only in one direction (from DP
IN adapter to DP OUT adapter), USB3 adds separate bandwidth for both
upstream and downstream directions.

For this reason extend the tunnel consumed bandwidth routines to support
both directions and implement this for DP.

Signed-off-by: Mika Westerberg

thunderbolt: Make usb4_switch_map_pcie_down() also return enabled ports

2020-06-22T16:58:20+00:00

Just for symmetry with the usb4_switch_map_usb3_down() make this one
also return ports that are enabled.

Signed-off-by: Mika Westerberg

thunderbolt: Make usb4_switch_map_usb3_down() also return enabled ports

2020-06-22T16:58:20+00:00

We need to call this on enabled ports in order to find the mapping from
host router USB4 port to a USB 3.x downstream adapter, so make the
function return enabled ports as well.

While there fix parameter alignment in tb_find_usb3_down().

Signed-off-by: Mika Westerberg

thunderbolt: Do not tunnel USB3 if link is not USB4

2020-06-22T16:58:20+00:00

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

thunderbolt: Add DP IN resources for all routers

2020-06-22T16:58:20+00:00

USB4 spec allows DP tunneling from any router that has DP IN adapter,
not just from host router. The driver currently only added the DP IN
resources for the host router because Thunderbolt 1, 2 and 3 devices do
not have DP IN adapters. However, USB4 allows device routers to have DP
IN adapter as well so update the driver to add DP IN resources for each
device that has one. One example would be an eGPU enclosure where the
eGPU output is forwarded to DP IN port and then tunneled over the USB4
fabric.

Only limitation we add now is that the DP IN and DP OUT that gets paired
for tunnel creation should both be under the same topology starting from
host router downstream port. In other words we do not create DP tunnels
across host router at this time even though that is possible as well but
it complicates the bandwidth management and there is no real use-case
for this anyway.

Signed-off-by: Mika Westerberg

thunderbolt: Add support for USB 3.x tunnels

2019-12-18T14:41:40+00:00

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 
Co-developed-by: Mika Westerberg 
Signed-off-by: Mika Westerberg 
Link: https://lore.kernel.org/r/20191217123345.31850-9-mika.westerberg@linux.intel.com
Signed-off-by: Greg Kroah-Hartman

thunderbolt: Add support for Time Management Unit

2019-12-18T14:41:15+00:00

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 
Co-developed-by: Mika Westerberg 
Signed-off-by: Mika Westerberg 
Link: https://lore.kernel.org/r/20191217123345.31850-8-mika.westerberg@linux.intel.com
Signed-off-by: Greg Kroah-Hartman

thunderbolt: Add initial support for USB4

2019-12-18T14:38:55+00:00

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 
Signed-off-by: Rajmohan Mani 
Signed-off-by: Mika Westerberg 
Link: https://lore.kernel.org/r/20191217123345.31850-5-mika.westerberg@linux.intel.com
Signed-off-by: Greg Kroah-Hartman