From 7d4b5ca2e2cb5d28db628ec79c706bcfa832feea Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Wed, 9 Jun 2021 09:01:46 -0700 Subject: cxl/acpi: Add downstream port data to cxl_port instances In preparation for infrastructure that enumerates and configures the CXL decode mechanism of an upstream port to its downstream ports, add a representation of a CXL downstream port. On ACPI systems the top-most logical downstream ports in the hierarchy are the host bridges (ACPI0016 devices) that decode the memory windows described by the CXL Early Discovery Table Fixed Memory Window Structures (CEDT.CFMWS). Reviewed-by: Alison Schofield Link: https://lore.kernel.org/r/162325450624.2293126.3533006409920271718.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams --- Documentation/ABI/testing/sysfs-bus-cxl | 13 +++++++++++++ 1 file changed, 13 insertions(+) (limited to 'Documentation') diff --git a/Documentation/ABI/testing/sysfs-bus-cxl b/Documentation/ABI/testing/sysfs-bus-cxl index bda2cc55cc38..f680da85fd44 100644 --- a/Documentation/ABI/testing/sysfs-bus-cxl +++ b/Documentation/ABI/testing/sysfs-bus-cxl @@ -44,3 +44,16 @@ Description: CXL component registers. The 'uport' symlink connects the CXL portX object to the device that published the CXL port capability. + +What: /sys/bus/cxl/devices/portX/dportY +Date: June, 2021 +KernelVersion: v5.14 +Contact: linux-cxl@vger.kernel.org +Description: + CXL port objects are enumerated from either a platform firmware + device (ACPI0017 and ACPI0016) or PCIe switch upstream port with + CXL component registers. The 'dportY' symlink identifies one or + more downstream ports that the upstream port may target in its + decode of CXL memory resources. The 'Y' integer reflects the + hardware port unique-id used in the hardware decoder target + list. -- cgit v1.3-14-g43fede