ACPI: Add documentation for exposing MRRM data

Initial implementation provides enumeration of the address ranges
NUMA node numbers, and BIOS assigned region IDs for each range.

Signed-off-by: Tony Luck <tony.luck@intel.com>
Link: https://patch.msgid.link/20250505173819.419271-4-tony.luck@intel.com
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

diff --git a/Documentation/ABI/testing/sysfs-firmware-acpi b/Documentation/ABI/testing/sysfs-firmware-acpi
index 5249ad5a96d98a70ad97146d7c12c1d0be426324..f4de60c4134d40786062648614ebebdff91e124b 100644 (file)
--- a/Documentation/ABI/testing/sysfs-firmware-acpi
+++ b/Documentation/ABI/testing/sysfs-firmware-acpi
@@ -248,3 +248,24 @@ Description:
                  # cat ff_pwr_btn
                  7     enabled
 
+What:          /sys/firmware/acpi/memory_ranges/rangeX
+Date:          February 2025
+Contact:       Tony Luck <tony.luck@intel.com>
+Description:
+               On systems with the ACPI MRRM table reports the parameters for
+               each range.
+
+               base: Starting system physical address.
+
+               length: Length of this range in bytes.
+
+               node: NUMA node that this range belongs to. Negative numbers
+               indicate that the node number could not be determined (e.g
+               for an address range that is reserved for future hot add of
+               memory).
+
+               local_region_id: ID associated with access by agents
+               local to this range of addresses.
+
+               remote_region_id: ID associated with access by agents
+               non-local to this range of addresses.