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authorDan Williams <dan.j.williams@intel.com>2021-06-09 19:01:46 +0300
committerDan Williams <dan.j.williams@intel.com>2021-06-10 04:02:39 +0300
commit7d4b5ca2e2cb5d28db628ec79c706bcfa832feea (patch)
tree833b93b5d980d417f1bac66dff19607dbb15c409 /Documentation/ABI
parent3feaa2d35880de935fc0d02acf808f355564f4e6 (diff)
downloadlinux-7d4b5ca2e2cb5d28db628ec79c706bcfa832feea.tar.xz
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 <alison.schofield@intel.com> Link: https://lore.kernel.org/r/162325450624.2293126.3533006409920271718.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Diffstat (limited to 'Documentation/ABI')
-rw-r--r--Documentation/ABI/testing/sysfs-bus-cxl13
1 files changed, 13 insertions, 0 deletions
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.