linux.git/drivers/thunderbolt/tb.c, branch v5.8

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

thunderbolt: Populate PG field in hot plug acknowledgment packet

2019-12-18T14:34:25+00:00

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 
Link: https://lore.kernel.org/r/20191217123345.31850-4-mika.westerberg@linux.intel.com
Signed-off-by: Greg Kroah-Hartman

thunderbolt: Make tb_find_port() available to other files

2019-12-18T14:34:23+00:00

We will be needing this when adding initial USB4 support so make it
available to other files in the driver as well. We also rename it to
tb_switch_find_port() to follow conventions used in switch.c.

No functional changes.

Signed-off-by: Mika Westerberg 
Link: https://lore.kernel.org/r/20191217123345.31850-2-mika.westerberg@linux.intel.com
Signed-off-by: Greg Kroah-Hartman

thunderbolt: Do not start firmware unless asked by the user

2019-11-02T09:13:31+00:00

Since now we can do pretty much the same thing in the software
connection manager than the firmware would do, there is no point
starting it by default. Instead we can just continue using the software
connection manager.

Make it possible for user to switch between the two by adding a module
pararameter (start_icm) which is by default false. Having this ability
to enable the firmware may be useful at least when debugging possible
issues with the software connection manager implementation.

Signed-off-by: Mika Westerberg

thunderbolt: Add bandwidth management for Display Port tunnels

2019-11-02T09:13:31+00:00

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

thunderbolt: Add Display Port adapter pairing and resource management

2019-11-02T09:13:31+00:00

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

thunderbolt: Add downstream PCIe port mappings for Alpine and Titan Ridge

2019-11-02T09:13:31+00:00

In order to keep PCIe hierarchies consistent across hotplugs, add
hard-coded PCIe downstream port to Thunderbolt port for Alpine Ridge and
Titan Ridge as well.

Signed-off-by: Mika Westerberg

thunderbolt: Expand controller name in tb_switch_is_xy()

2019-11-02T09:13:31+00:00

For a casual reader tb_switch_is_cr() does not tell much so instead
spell out the full controller name in the function name. For example
tb_switch_is_cr() becomes tb_switch_is_cactus_ridge() which is easier
to understand.

Signed-off-by: Mika Westerberg