amd-cppc is the AMD CPU performance scaling driver that introduces a
new CPU frequency control mechanism on modern AMD APU and CPU series in
Xen. The new mechanism is based on Collaborative Processor Performance
Control (CPPC) which provides finer grain frequency management than
legacy ACPI hardware P-States. Current AMD CPU/APU platforms are using
the ACPI P-states driver to manage CPU frequency and clocks with
switching only in 3 P-states. CPPC replaces the ACPI P-states controls
and allows a flexible, low-latency interface for Xen to directly
communicate the performance hints to hardware.
amd_cppc driver has 2 operation modes: autonomous (active) mode,
and non-autonomous (passive) mode. We register different CPUFreq driver
for different modes, "amd-cppc" for passive mode and "amd-cppc-epp"
for active mode.
The passive mode leverages common governors such as *ondemand*,
*performance*, etc, to manage the performance hints. And the active mode
uses epp to provides a hint to the hardware if software wants to bias
toward performance (0x0) or energy efficiency (0xff). CPPC power algorithm
in hardware will automatically calculate the runtime workload and adjust the
realtime cpu cores frequency according to the power supply and thermal, core
voltage and some other hardware conditions.
amd-cppc is enabled on passive mode with a top-level `cpufreq=amd-cppc` option,
while users add extra `active` flag to select active mode.
With `cpufreq=amd-cppc,active`, we did a 60s sampling test to see the CPU
frequency change, through tweaking the energy_perf preference from
`xenpm set-cpufreq-cppc powersave` to `xenpm set-cpufreq-cppc performance`.
The outputs are as follows:
```
Setting CPU in powersave mode
Sampling and Outputs:
Avg freq 2000000 KHz
Avg freq 2000000 KHz
Avg freq 2000000 KHz
Setting CPU in performance mode
Sampling and Outputs:
Avg freq 4640000 KHz
Avg freq 4220000 KHz
Avg freq 4640000 KHz
Penny Zheng (15):
xen/cpufreq: introduces XEN_PM_PSD for solely delivery of _PSD
xen/x86: introduce new sub-hypercall to propagate CPPC data
xen/cpufreq: refactor cmdline "cpufreq=xxx"
xen/cpufreq: move XEN_PROCESSOR_PM_xxx to internal header
xen/x86: introduce "cpufreq=amd-cppc" xen cmdline
xen/cpufreq: disable px statistic info in amd-cppc mode
xen/cpufreq: fix core frequency calculation for AMD Family 1Ah CPUs
xen/amd: export processor max frequency value
xen/x86: introduce a new amd cppc driver for cpufreq scaling
xen/cpufreq: only set gov NULL when cpufreq_driver.setpolicy is NULL
xen/cpufreq: abstract Energy Performance Preference value
xen/x86: implement EPP support for the amd-cppc driver in active mode
tools/xenpm: Print CPPC parameters for amd-cppc driver
xen/xenpm: Adapt cpu frequency monitor in xenpm
xen/cpufreq: Adapt SET/GET_CPUFREQ_CPPC xen_sysctl_pm_op for amd-cppc
driver
docs/misc/xen-command-line.pandoc | 27 +-
tools/libs/ctrl/xc_pm.c | 12 +-
tools/misc/xenpm.c | 23 +-
xen/arch/x86/acpi/cpufreq/Makefile | 1 +
xen/arch/x86/acpi/cpufreq/acpi.c | 14 +-
xen/arch/x86/acpi/cpufreq/amd-cppc.c | 681 ++++++++++++++++++++++
xen/arch/x86/acpi/cpufreq/cpufreq.c | 34 +-
xen/arch/x86/acpi/cpufreq/hwp.c | 10 +-
xen/arch/x86/acpi/cpufreq/powernow.c | 2 +-
xen/arch/x86/cpu/amd.c | 37 +-
xen/arch/x86/include/asm/amd.h | 1 +
xen/arch/x86/include/asm/msr-index.h | 5 +
xen/arch/x86/platform_hypercall.c | 25 +
xen/arch/x86/pv/dom0_build.c | 1 -
xen/arch/x86/setup.c | 1 +
xen/arch/x86/x86_64/cpufreq.c | 4 +
xen/common/domain.c | 1 +
xen/drivers/acpi/pmstat.c | 54 +-
xen/drivers/cpufreq/cpufreq.c | 258 +++++---
xen/drivers/cpufreq/cpufreq_ondemand.c | 2 +-
xen/drivers/cpufreq/utility.c | 18 +
xen/include/acpi/cpufreq/cpufreq.h | 31 +
xen/include/acpi/cpufreq/processor_perf.h | 18 +-
xen/include/public/platform.h | 38 +-
xen/include/public/sysctl.h | 2 +
xen/include/public/xen.h | 1 -
xen/include/xen/pmstat.h | 4 +
xen/include/xlat.lst | 3 +-
28 files changed, 1160 insertions(+), 148 deletions(-)
create mode 100644 xen/arch/x86/acpi/cpufreq/amd-cppc.c
--
2.34.1