From d1ff70241a275133e1a0258b7c23588b122276c8 Mon Sep 17 00:00:00 2001 From: Mika Westerberg Date: Mon, 2 Oct 2017 13:38:34 +0300 Subject: 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 Signed-off-by: Mika Westerberg Reviewed-by: Yehezkel Bernat Reviewed-by: Andy Shevchenko Signed-off-by: David S. Miller --- Documentation/ABI/testing/sysfs-bus-thunderbolt | 48 +++++++++++++++++++++++++ 1 file changed, 48 insertions(+) (limited to 'Documentation/ABI') diff --git a/Documentation/ABI/testing/sysfs-bus-thunderbolt b/Documentation/ABI/testing/sysfs-bus-thunderbolt index 392bef5bd399..93798c02e28b 100644 --- a/Documentation/ABI/testing/sysfs-bus-thunderbolt +++ b/Documentation/ABI/testing/sysfs-bus-thunderbolt @@ -110,3 +110,51 @@ Description: When new NVM image is written to the non-active NVM is directly the status value from the DMA configuration based mailbox before the device is power cycled. Writing 0 here clears the status. + +What: /sys/bus/thunderbolt/devices/./key +Date: Jan 2018 +KernelVersion: 4.15 +Contact: thunderbolt-software@lists.01.org +Description: This contains name of the property directory the XDomain + service exposes. This entry describes the protocol in + question. Following directories are already reserved by + the Apple XDomain specification: + + network: IP/ethernet over Thunderbolt + targetdm: Target disk mode protocol over Thunderbolt + extdisp: External display mode protocol over Thunderbolt + +What: /sys/bus/thunderbolt/devices/./modalias +Date: Jan 2018 +KernelVersion: 4.15 +Contact: thunderbolt-software@lists.01.org +Description: Stores the same MODALIAS value emitted by uevent for + the XDomain service. Format: tbtsvc:kSpNvNrN + +What: /sys/bus/thunderbolt/devices/./prtcid +Date: Jan 2018 +KernelVersion: 4.15 +Contact: thunderbolt-software@lists.01.org +Description: This contains XDomain protocol identifier the XDomain + service supports. + +What: /sys/bus/thunderbolt/devices/./prtcvers +Date: Jan 2018 +KernelVersion: 4.15 +Contact: thunderbolt-software@lists.01.org +Description: This contains XDomain protocol version the XDomain + service supports. + +What: /sys/bus/thunderbolt/devices/./prtcrevs +Date: Jan 2018 +KernelVersion: 4.15 +Contact: thunderbolt-software@lists.01.org +Description: This contains XDomain software version the XDomain + service supports. + +What: /sys/bus/thunderbolt/devices/./prtcstns +Date: Jan 2018 +KernelVersion: 4.15 +Contact: thunderbolt-software@lists.01.org +Description: This contains XDomain service specific settings as + bitmask. Format: %x -- cgit v1.2.3