Subject: [PATCH v5 0/6] Add support for FORM2 associativity

From: "Aneesh Kumar K.V" <[email-masked]>
Date: Mon, 28 Jun 2021 20:41:11 +0530

Form2 associativity adds a much more flexible NUMA topology layout
than what is provided by Form1. More details can be found in patch 7.

$ numactl -H
...
node distances:
node   0   1   2   3 
  0:  10  11  222  33 
  1:  44  10  55  66 
  2:  77  88  10  99 
  3:  101  121  132  10 
$

After DAX kmem memory add
# numactl -H
available: 5 nodes (0-4)
...
node distances:
node   0   1   2   3   4 
  0:  10  11  222  33  240 
  1:  44  10  55  66  255 
  2:  77  88  10  99  255 
  3:  101  121  132  10  230 
  4:  255  255  255  230  10 

PAPR SCM now use the numa distance details to find the numa_node and target_node
for the device.

kvaneesh@ubuntu-guest:~$ ndctl  list -N -v 
[
  {
    "dev":"namespace0.0",
    "mode":"devdax",
    "map":"dev",
    "size":1071644672,
    "uuid":"d333d867-3f57-44c8-b386-d4d3abdc2bf2",
    "raw_uuid":"915361ad-fe6a-42dd-848f-d6dc9f5af362",
    "daxregion":{
      "id":0,
      "size":1071644672,
      "devices":[
        {
          "chardev":"dax0.0",
          "size":1071644672,
          "target_node":4,
          "mode":"devdax"
        }
      ]
    },
    "align":2097152,
    "numa_node":3
  }
]
kvaneesh@ubuntu-guest:~$ 

The above output is with a Qemu command line

-numa node,nodeid=4 \
-numa dist,src=0,dst=1,val=11 -numa dist,src=0,dst=2,val=222 -numa dist,src=0,dst=3,val=33 -numa dist,src=0,dst=4,val=240 \
-numa dist,src=1,dst=0,val=44 -numa dist,src=1,dst=2,val=55 -numa dist,src=1,dst=3,val=66 -numa dist,src=1,dst=4,val=255 \
-numa dist,src=2,dst=0,val=77 -numa dist,src=2,dst=1,val=88 -numa dist,src=2,dst=3,val=99 -numa dist,src=2,dst=4,val=255 \
-numa dist,src=3,dst=0,val=101 -numa dist,src=3,dst=1,val=121 -numa dist,src=3,dst=2,val=132 -numa dist,src=3,dst=4,val=230 \
-numa dist,src=4,dst=0,val=255 -numa dist,src=4,dst=1,val=255 -numa dist,src=4,dst=2,val=255 -numa dist,src=4,dst=3,val=230 \
-object memory-backend-file,id=memnvdimm1,prealloc=yes,mem-path=$PMEM_DISK,share=yes,size=${PMEM_SIZE}  \
-device nvdimm,label-size=128K,memdev=memnvdimm1,id=nvdimm1,slot=4,uuid=72511b67-0b3b-42fd-8d1d-5be3cae8bcaa,node=4

Qemu changes can be found at https://lore.kernel.org/qemu-devel/[email-masked]/

Changes from v4:
* Drop DLPAR related device tree property for now because both Qemu nor PowerVM
  will provide the distance details of all possible NUMA nodes during boot.
* Rework numa distance code based on review feedback.

Changes from v3:
* Drop PAPR SCM specific changes and depend completely on NUMA distance information.

Changes from v2:
* Add nvdimm list to Cc:
* update PATCH 8 commit message.

Changes from v1:
* Update FORM2 documentation.
* rename max_domain_index to max_associativity_domain_index

Aneesh Kumar K.V (6):
  powerpc/pseries: rename min_common_depth to primary_domain_index
  powerpc/pseries: rename distance_ref_points_depth to
    max_associativity_domain_index
  powerpc/pseries: Rename TYPE1_AFFINITY to FORM1_AFFINITY
  powerpc/pseries: Consolidate different NUMA distance update code paths
  powerpc/pseries: Add a helper for form1 cpu distance
  powerpc/pseries: Add support for FORM2 associativity

 Documentation/powerpc/associativity.rst       | 103 +++++
 arch/powerpc/include/asm/firmware.h           |   7 +-
 arch/powerpc/include/asm/prom.h               |   3 +-
 arch/powerpc/include/asm/topology.h           |   4 +-
 arch/powerpc/kernel/prom_init.c               |   3 +-
 arch/powerpc/mm/numa.c                        | 415 +++++++++++++-----
 arch/powerpc/platforms/pseries/firmware.c     |   3 +-
 arch/powerpc/platforms/pseries/hotplug-cpu.c  |   2 +
 .../platforms/pseries/hotplug-memory.c        |   2 +
 arch/powerpc/platforms/pseries/lpar.c         |   4 +-
 arch/powerpc/platforms/pseries/pseries.h      |   1 +
 11 files changed, 432 insertions(+), 115 deletions(-)
 create mode 100644 Documentation/powerpc/associativity.rst

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2.31.1