Updates to SSDT topology - Asa-dev - op-lists.linaro.org

29 Aug 2020


      Hi All,
While making the MPIDR related changes in UEFI, i.e reading it
from QEMU's device tree based on Leif's patch I thought of
updating the SSDT and PPTT topologies to match it.
The current SSDT table is implemented without a cluster and core
kind of topology. So it looks as follows
Scope (_SB) {
  Device (C000) {
    Name (_HID, "ACPI0007"),
    Name (_UID, 0)
  }
  ...
  ...
  Device (Cxxx) {
    Name (_HID, "ACPI0007"),
    Name (_UID, coreid)
  }
}
After looking at Graeme's TF-A tree, the topology would be as follows
  - No SMT since MT bit isn't set
  - Cluster with upto 8 Cores
  - N clusters which is set at 64 currently
So I'm thinking to updating SSDT table with the following structure
Scope (_SB) {
  Device (CL00) {                           // Cluster 0
    Name (_HID, "ACPI0010"),
    Name (_UID, 0x0)
Device (CP00) {                        // Cluster 0 Cpu0
      Name (_HID, "ACPI0007"),
      Name (_UID, (clusterid | 0x0)),
    }
    ...
    Device (CP07) {                        // Cluster 0 Cpu 7
      Name (_HID, "ACPI0007"),
      Name (_UID, (clusterid | coreid)),
    }
 }
 ...
 ...
  Device (CLXX) {                          // Cluster 63
    Name (_HID, "ACPI0010"),
    Name (_UID, clusteridx)
Device (CP00) {                        // Cluster 63 Cpu 0
      Name (_HID, "ACPI0007"),
      Name (_UID, (clusteridx | coreidx)),
    }
    ...
    Device (CP07) {                        // Cluster 63 CPU 7
      Name (_HID, "ACPI0007"),
      Name (_UID, (clusteridx | coreidx)),
    }
 }
}
Can you please review this structure and let me know if I can
go ahead and make these changes in SSDT and PPTT table generation ?
With Regards,
Tanmay