Re: [PATCH v3 0/7] Support PPTT for ARM64

From: Jeremy Linton
Date: Fri Oct 13 2017 - 15:35:00 EST


Hi,

On 10/13/2017 06:08 AM, John Garry wrote:
On 12/10/2017 20:48, Jeremy Linton wrote:
ACPI 6.2 adds the Processor Properties Topology Table (PPTT), which is
used to describe the processor and cache topology. Ideally it is
used to extend/override information provided by the hardware, but
right now ARM64 is entirely dependent on firmware provided tables.

This patch parses the table for the cache topology and CPU topology.
For the latter we also add an additional topology_cod_id() macro,
and a package_id for arm64. Initially the physical id will match
the cluster id, but we update users of the cluster to utilize
the new macro. When we enable ACPI/PPTT for arm64 we map the socket
to the physical id as the remainder of the kernel expects.


Hi Jeremy,

Can you put this series on a public branch for convenience of review and test?

Let me see what I can do..


Also, what is your idea for supporting Type 2 ID structure?

I don't have any plans, as you can see the current patches ignore the ID nodes. It should be fairly easy to mine the information from the tables, but what parts are necessary or where to use them isn't clear to me.

Suggestions welcome.



Cheers,
John

For example on juno:
[root@mammon-juno-rh topology]# lstopo-no-graphics
  Package L#0
    L2 L#0 (1024KB)
      L1d L#0 (32KB) + L1i L#0 (32KB) + Core L#0 + PU L#0 (P#0)
      L1d L#1 (32KB) + L1i L#1 (32KB) + Core L#1 + PU L#1 (P#1)
      L1d L#2 (32KB) + L1i L#2 (32KB) + Core L#2 + PU L#2 (P#2)
      L1d L#3 (32KB) + L1i L#3 (32KB) + Core L#3 + PU L#3 (P#3)
    L2 L#1 (2048KB)
      L1d L#4 (32KB) + L1i L#4 (48KB) + Core L#4 + PU L#4 (P#4)
      L1d L#5 (32KB) + L1i L#5 (48KB) + Core L#5 + PU L#5 (P#5)
  HostBridge L#0
    PCIBridge
      PCIBridge
        PCIBridge
          PCI 1095:3132
            Block(Disk) L#0 "sda"
        PCIBridge
          PCI 1002:68f9
            GPU L#1 "renderD128"
            GPU L#2 "card0"
            GPU L#3 "controlD64"
        PCIBridge
          PCI 11ab:4380
            Net L#4 "enp8s0"

v2->v3:

Remove valid bit check on leaf nodes. Now simply being a leaf node
  is sufficient to verify the processor id against the ACPI
  processor ids (gotten from MADT).

Use the acpi processor for the "level 0" Id. This makes the /sys
  visible core/thread ids more human readable if the firmware uses
  small consecutive values for processor ids.

Added PPTT to the list of injectable ACPI tables.

Fix bug which kept the code from using the processor node as intended
  in v2, caused by misuse of git rebase/fixup.

v1->v2:

The parser keys off the acpi_pptt_processor node to determine
  unique cache's rather than the acpi_pptt_cache referenced by the
  processor node. This allows PPTT tables which "share" cache nodes
  across cpu nodes despite not being a shared cache.

Normalize the socket, cluster and thread mapping so that they match
  linux's traditional mapping for the physical id, and thread id.
  Adding explicit scheduler knowledge of clusters (rather than just
  their cache sharing attributes) is a subject for a future patch.

Jeremy Linton (7):
  ACPI/PPTT: Add Processor Properties Topology Table parsing
  ACPI: Enable PPTT support on ARM64
  drivers: base: cacheinfo: arm64: Add support for ACPI based firmware
    tables
  Topology: Add cluster on die macros and arm64 decoding
  arm64: Fixup users of topology_physical_package_id
  arm64: topology: Enable ACPI/PPTT based CPU topology.
  ACPI: Add PPTT to injectable table list

 arch/arm64/Kconfig                |   1 +
 arch/arm64/include/asm/topology.h |   4 +-
 arch/arm64/kernel/cacheinfo.c     |  23 +-
 arch/arm64/kernel/topology.c      |  62 ++++-
 drivers/acpi/Makefile             |   1 +
 drivers/acpi/arm64/Kconfig        |   3 +
 drivers/acpi/pptt.c               | 486 ++++++++++++++++++++++++++++++++++++++
 drivers/acpi/tables.c             |   3 +-
 drivers/base/cacheinfo.c          |  17 +-
 drivers/cpufreq/arm_big_little.c  |   2 +-
 drivers/firmware/psci_checker.c   |   2 +-
 include/linux/cacheinfo.h         |  11 +-
 include/linux/topology.h          |   4 +
 13 files changed, 599 insertions(+), 20 deletions(-)
 create mode 100644 drivers/acpi/pptt.c