[PATCH v3 0/3] arch_topology, ACPI: populate cpu capacity from CPPC

Ionela Voinescu
2022-03-02T18:09:50Z

Hi all,

v2->v3:
- v2 can be found at [2]
- Added sanity checking on perf_caps.highest_perf

v1->v2:
- v1 can be found at [1]
- Changed debug prints to the format used on the DT path
- s/init_cpu_capacity_cppc/topology_init_cpu_capacity_cppc

Patches are based on v5.17-rc6.

The patches have been build tested on x86 and more thoroughly tested on
Juno R2 (arm64), which uses the new functionality, with the following
results:

root@buildroot:~# dmesg | grep cpu_capacity
[ 2.191152] cpu_capacity: CPU0 cpu_capacity=38300 (raw).
[ 2.196482] cpu_capacity: CPU1 cpu_capacity=38300 (raw).
[ 2.201809] cpu_capacity: CPU2 cpu_capacity=38300 (raw).
[ 2.207136] cpu_capacity: CPU3 cpu_capacity=38300 (raw).
[ 2.212463] cpu_capacity: CPU4 cpu_capacity=102400 (raw).
[ 2.217877] cpu_capacity: CPU5 cpu_capacity=102400 (raw).
[ 2.223291] cpu_capacity: capacity_scale=102400
[ 2.227834] cpu_capacity: CPU0 cpu_capacity=383
[ 2.232376] cpu_capacity: CPU1 cpu_capacity=383
[ 2.236919] cpu_capacity: CPU2 cpu_capacity=383
[ 2.241462] cpu_capacity: CPU3 cpu_capacity=383
[ 2.246004] cpu_capacity: CPU4 cpu_capacity=1024
[ 2.250634] cpu_capacity: CPU5 cpu_capacity=1024
[ 2.255321] cpu_capacity: cpu_capacity initialization done

root@buildroot:~# tail -n +1 /sys/devices/system/cpu/cpu*/cpu_capacity
==> /sys/devices/system/cpu/cpu0/cpu_capacity <==
383
==> /sys/devices/system/cpu/cpu1/cpu_capacity <==
383
==> /sys/devices/system/cpu/cpu2/cpu_capacity <==
383
==> /sys/devices/system/cpu/cpu3/cpu_capacity <==
383
==> /sys/devices/system/cpu/cpu4/cpu_capacity <==
1024
==> /sys/devices/system/cpu/cpu5/cpu_capacity <==
1024

[1]
https://lore.kernel.org/lkml/20210514095339.12979-1-ionela.voinescu@arm.com/
[2]
https://lore.kernel.org/lkml/20210824105651.28660-1-ionela.voinescu@arm.com/

Thanks,
Ionela.

Ionela Voinescu (3):
x86, ACPI: rename init_freq_invariance_cppc to
arch_init_invariance_cppc
arch_topology: obtain cpu capacity using information from CPPC
arm64, topology: enable use of init_cpu_capacity_cppc()

arch/arm64/include/asm/topology.h | 4 ++++
arch/x86/include/asm/topology.h | 2 +-
drivers/acpi/cppc_acpi.c | 6 ++---
drivers/base/arch_topology.c | 40 +++++++++++++++++++++++++++++++
include/linux/arch_topology.h | 4 ++++
5 files changed, 52 insertions(+), 4 deletions(-)

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2.25.1