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[v5,0/3] Add interfaces for ACPI MRRM table

Message ID 20250505173819.419271-1-tony.luck@intel.com
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Series Add interfaces for ACPI MRRM table | expand

Message

Luck, Tony May 5, 2025, 5:38 p.m. UTC 
This series based on:
	https://web.git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm.git/log/?h=testing

Memory used to be homogeneous. Then NUMA came along. Later different
types of memory (persistent memory, on-package high bandwidth memory,
CXL attached memory).

Each type of memory has its own performance characteristics, and users
will need to monitor and control access by type.

The MRRM solution is to tag physical address ranges with "region IDs"
so that platform firmware[1] can indicate the type of memory for each
range (with separate tags available for local vs. remote access to
each range). Note that these ranges can include addresses reserved
for future hotplugged memory.

The region IDs will be used to provide separate event counts for each
region for "perf" and for the "resctrl" file system to monitor and
control memory bandwidth in each region.

Users will need to know the address range(s) that are part of each
region. This patch series adds
	/sys/firmware/acpi/memory_ranges/rangeX
directories to provide user space accessible enumeration.

-Tony

[1] MRRM definition allow for future expansion for the OS to assign
these region IDs.

Changes since version 4 here:
https://lore.kernel.org/all/20250429202412.380637-1-tony.luck@intel.com/

*) Dropped patch 1. ACPICA changes have been merged into the linux-pm
   tree.
*) Removed spurious blank file from mrrm_init() (Thanks, Fenghua).

Tony Luck (3):
  ACPI/MRRM: Minimal parse of ACPI MRRM table
  ACPI/MRRM: Add /sys files to describe memory ranges
  ACPI: Add documentation for exposing MRRM data

 include/linux/acpi.h                          |   9 +
 drivers/acpi/acpi_mrrm.c                      | 182 ++++++++++++++++++
 Documentation/ABI/testing/sysfs-firmware-acpi |  21 ++
 arch/x86/Kconfig                              |   1 +
 drivers/acpi/Kconfig                          |   3 +
 drivers/acpi/Makefile                         |   1 +
 6 files changed, 217 insertions(+)
 create mode 100644 drivers/acpi/acpi_mrrm.c


base-repo: git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm.git
base-branch: testing
base-commit: 70cb3b9a371fe9ff4f50cd7889763abd4ab621dc