[v7,0/6] cpufreq: amd-pstate: Add guided autonomous mode support

  From ACPI spec[1] below 3 modes for CPPC can be defined:
1. Non autonomous: OS scaling governor specifies operating frequency/
   performance level through `Desired Performance` register and platform
follows that.
2. Guided autonomous: OS scaling governor specifies min and max
   frequencies/ performance levels through `Minimum Performance` and
`Maximum Performance` register, and platform can autonomously select an
operating frequency in this range.
3. Fully autonomous: OS only hints (via EPP) to platform for the required
   energy performance preference for the workload and platform autonomously
scales the frequency.

Currently (1) is supported by amd_pstate as passive mode, and (3) is
implemented by EPP support[2]. This change is to support (2).

In guided autonomous mode the min_perf is based on the input from the
scaling governor. For example, in case of schedutil this value depends
on the current utilization. And max_perf is set to max capacity.

To activate guided auto mode ``amd_pstate=guided`` command line
parameter has to be passed in the kernel.

Below are the results (normalized) of benchmarks with this patch:
System: Genoa 96C 192T
Kernel: 6.2.0-rc2 + EPP v12 + patch
Scaling governor: schedutil

================ dbench comparisons ================
dbench result comparison:
Here results are throughput (MB/s)
Clients:   acpi-cpufreq		   amd_pst+passive	   amd_pst+guided
    1	   1.00 (0.00 pct)	   1.01 (1.00 pct)	   1.02 (2.00 pct)
    2	   1.07 (0.00 pct)	   1.06 (-0.93 pct)	   1.07 (0.00 pct)
    4	   1.68 (0.00 pct)	   1.70 (1.19 pct)	   1.72 (2.38 pct)
    8	   2.61 (0.00 pct)	   2.68 (2.68 pct)	   2.76 (5.74 pct)
   16	   4.16 (0.00 pct)	   4.24 (1.92 pct)	   4.53 (8.89 pct)
   32	   5.98 (0.00 pct)	   6.17 (3.17 pct)	   7.30 (22.07 pct)
   64	   8.67 (0.00 pct)	   8.99 (3.69 pct)	  10.71 (23.52 pct)
  128	  11.98 (0.00 pct)	  12.52 (4.50 pct)	  14.67 (22.45 pct)
  256	  15.73 (0.00 pct)	  16.13 (2.54 pct)	  17.81 (13.22 pct)
  512	  15.77 (0.00 pct)	  16.32 (3.48 pct)	  16.39 (3.93 pct)
dbench power comparison:
Clients:   acpi-cpufreq		   amd_pst+passive	   amd_pst+guided
    1	   1.00 (0.00 pct)	   1.00 (0.00 pct)	   1.04 (4.00 pct)
    2	   0.99 (0.00 pct)	   0.97 (-2.02 pct)	   1.02 (3.03 pct)
    4	   0.98 (0.00 pct)	   0.98 (0.00 pct)	   1.02 (4.08 pct)
    8	   0.98 (0.00 pct)	   0.99 (1.02 pct)	   1.02 (4.08 pct)
   16	   0.99 (0.00 pct)	   1.00 (1.01 pct)	   1.04 (5.05 pct)
   32	   1.02 (0.00 pct)	   1.02 (0.00 pct)	   1.07 (4.90 pct)
   64	   1.05 (0.00 pct)	   1.05 (0.00 pct)	   1.11 (5.71 pct)
  128	   1.08 (0.00 pct)	   1.08 (0.00 pct)	   1.15 (6.48 pct)
  256	   1.12 (0.00 pct)	   1.12 (0.00 pct)	   1.20 (7.14 pct)
  512	   1.18 (0.00 pct)	   1.17 (-0.84 pct)	   1.26 (6.77 pct)

================ git-source comparisons ================
git-source result comparison:
Here results are throughput (compilations per 1000 sec)
Threads:   acpi-cpufreq		   amd_pst+passive	   amd_pst+guided
  192	   1.00 (0.00 pct)	   0.93 (-7.00 pct)	   1.00 (0.00 pct)
git-source power comparison:
Threads:   acpi-cpufreq		   amd_pst+passive	   amd_pst+guided
  192	   1.00 (0.00 pct)	   1.00 (0.00 pct)	   0.96 (-4.00 pct)

================ kernbench comparisons ================
kernbench result comparison:
Here results are throughput (compilations per 1000 sec)
Load:	   acpi-cpufreq		   amd_pst+passive	   amd_pst+guided
32	   1.00 (0.00 pct)	   1.01 (1.00 pct)	   1.02 (2.00 pct)
48	   1.26 (0.00 pct)	   1.28 (1.58 pct)	   1.25 (-0.79 pct)
64	   1.39 (0.00 pct)	   1.47 (5.75 pct)	   1.43 (2.87 pct)
96	   1.48 (0.00 pct)	   1.50 (1.35 pct)	   1.49 (0.67 pct)
128	   1.29 (0.00 pct)	   1.32 (2.32 pct)	   1.33 (3.10 pct)
192	   1.17 (0.00 pct)	   1.20 (2.56 pct)	   1.21 (3.41 pct)
256	   1.17 (0.00 pct)	   1.18 (0.85 pct)	   1.20 (2.56 pct)
384	   1.16 (0.00 pct)	   1.17 (0.86 pct)	   1.21 (4.31 pct)
kernbench power comparison:
Clients:   acpi-cpufreq		   amd_pst+passive	   amd_pst+guided
   32	   1.00 (0.00 pct)	   0.97 (-3.00 pct)	   1.00 (0.00 pct)
   48	   0.87 (0.00 pct)	   0.81 (-6.89 pct)	   0.88 (1.14 pct)
   64	   0.81 (0.00 pct)	   0.73 (-9.87 pct)	   0.77 (-4.93 pct)
   96	   0.75 (0.00 pct)	   0.74 (-1.33 pct)	   0.75 (0.00 pct)
  128	   0.83 (0.00 pct)	   0.79 (-4.81 pct)	   0.83 (0.00 pct)
  192	   0.92 (0.00 pct)	   0.88 (-4.34 pct)	   0.92 (0.00 pct)
  256	   0.92 (0.00 pct)	   0.88 (-4.34 pct)	   0.92 (0.00 pct)
  384	   0.92 (0.00 pct)	   0.88 (-4.34 pct)	   0.92 (0.00 pct)

================ tbench comparisons ================
tbench result comparison:
Here results are throughput (MB/s)
Clients:   acpi-cpufreq		   amd_pst+passive	   amd_pst+guided
    1	   1.00 (0.00 pct)	   0.70 (-30.00 pct)	   1.37 (37.00 pct)
    2	   2.64 (0.00 pct)	   1.39 (-47.34 pct)	   2.70 (2.27 pct)
    4	   4.89 (0.00 pct)	   2.75 (-43.76 pct)	   5.28 (7.97 pct)
    8	   9.46 (0.00 pct)	   5.42 (-42.70 pct)	  10.22 (8.03 pct)
   16	  19.05 (0.00 pct)	  10.42 (-45.30 pct)	  19.94 (4.67 pct)
   32	  37.50 (0.00 pct)	  20.23 (-46.05 pct)	  36.87 (-1.68 pct)
   64	  61.24 (0.00 pct)	  43.08 (-29.65 pct)	  62.96 (2.80 pct)
  128	  67.16 (0.00 pct)	  69.08 (2.85 pct)	  67.34 (0.26 pct)
  256	 154.59 (0.00 pct)	 162.33 (5.00 pct)	 156.78 (1.41 pct)
  512	 154.02 (0.00 pct)	 156.74 (1.76 pct)	 153.48 (-0.35 pct)
tbench power comparison:
Clients:   acpi-cpufreq		   amd_pst+passive	   amd_pst+guided
    1	   1.00 (0.00 pct)	   0.97 (-3.00 pct)	   1.08 (8.00 pct)
    2	   1.04 (0.00 pct)	   0.97 (-6.73 pct)	   1.11 (6.73 pct)
    4	   1.12 (0.00 pct)	   0.99 (-11.60 pct)	   1.18 (5.35 pct)
    8	   1.25 (0.00 pct)	   1.04 (-16.80 pct)	   1.31 (4.80 pct)
   16	   1.53 (0.00 pct)	   1.13 (-26.14 pct)	   1.58 (3.26 pct)
   32	   2.01 (0.00 pct)	   1.36 (-32.33 pct)	   2.03 (0.99 pct)
   64	   2.58 (0.00 pct)	   2.14 (-17.05 pct)	   2.61 (1.16 pct)
  128	   2.80 (0.00 pct)	   2.81 (0.35 pct)	   2.81 (0.35 pct)
  256	   3.39 (0.00 pct)	   3.43 (1.17 pct)	   3.42 (0.88 pct)
  512	   3.44 (0.00 pct)	   3.44 (0.00 pct)	   3.44 (0.00 pct)

Note: this series is based on top of EPP v12 [3] series

Change log:

v6 -> v7:
- Addressed comments by Ray
- Reorder and rebase patches
- Pick up Ack by Ray

v5 -> v6:
- Don't return -EBUSY when changing to same mode

v4 -> v5:
- Rebased on top of EPP v12 series
- Addressed comments form Mario regarding documentation
- Picked up RB flags from Mario and Bagas Sanjaya

v3 -> v4:
- Fixed active mode low frequency issue reported by Peter Jung and Tor Vic
- Documentation modification suggested by Bagas Sanjaya

v2 -> v3:
- Addressed review comments form Mario.
- Picked up RB tag from Mario.
- Rebase on top of EPP v11 [3].

v1 -> v2:
- Fix issue with shared mem systems.
- Rebase on top of EPP series.

[1]: https://uefi.org/sites/default/files/resources/ACPI_6_3_final_Jan30.pdf
[2]: https://lore.kernel.org/lkml/20221110175847.3098728-1-Perry.Yuan@amd.com/
[3]: https://lore.kernel.org/linux-pm/20230131090016.3970625-1-perry.yuan@amd.com/

Wyes Karny (6):
  acpi: cppc: Add min and max perf reg writing support
  acpi: cppc: Add auto select register read/write support
  Documentation: cpufreq: amd-pstate: Move amd_pstate param to
    alphabetical order
  cpufreq: amd-pstate: Add guided autonomous mode
  cpufreq: amd-pstate: Add guided mode control support via sysfs
  Documentation: cpufreq: amd-pstate: Update amd_pstate status sysfs for
    guided

 .../admin-guide/kernel-parameters.txt         |  40 ++--
 Documentation/admin-guide/pm/amd-pstate.rst   |  31 ++-
 drivers/acpi/cppc_acpi.c                      | 121 +++++++++++-
 drivers/cpufreq/amd-pstate.c                  | 177 +++++++++++++-----
 include/acpi/cppc_acpi.h                      |  11 ++
 include/linux/amd-pstate.h                    |   2 +
 6 files changed, 302 insertions(+), 80 deletions(-)
  

On Thu, Feb 16, 2023 at 04:17:56PM +0800, Karny, Wyes wrote:
> From ACPI spec[1] below 3 modes for CPPC can be defined:
> 1. Non autonomous: OS scaling governor specifies operating frequency/
>    performance level through `Desired Performance` register and platform
> follows that.
> 2. Guided autonomous: OS scaling governor specifies min and max
>    frequencies/ performance levels through `Minimum Performance` and
> `Maximum Performance` register, and platform can autonomously select an
> operating frequency in this range.
> 3. Fully autonomous: OS only hints (via EPP) to platform for the required
>    energy performance preference for the workload and platform autonomously
> scales the frequency.
> 
> Currently (1) is supported by amd_pstate as passive mode, and (3) is
> implemented by EPP support[2]. This change is to support (2).
> 
> In guided autonomous mode the min_perf is based on the input from the
> scaling governor. For example, in case of schedutil this value depends
> on the current utilization. And max_perf is set to max capacity.
> 
> To activate guided auto mode ``amd_pstate=guided`` command line
> parameter has to be passed in the kernel.
> 
> Below are the results (normalized) of benchmarks with this patch:
> System: Genoa 96C 192T
> Kernel: 6.2.0-rc2 + EPP v12 + patch
> Scaling governor: schedutil
> 
> ================ dbench comparisons ================
> dbench result comparison:
> Here results are throughput (MB/s)
> Clients:   acpi-cpufreq		   amd_pst+passive	   amd_pst+guided
>     1	   1.00 (0.00 pct)	   1.01 (1.00 pct)	   1.02 (2.00 pct)
>     2	   1.07 (0.00 pct)	   1.06 (-0.93 pct)	   1.07 (0.00 pct)
>     4	   1.68 (0.00 pct)	   1.70 (1.19 pct)	   1.72 (2.38 pct)
>     8	   2.61 (0.00 pct)	   2.68 (2.68 pct)	   2.76 (5.74 pct)
>    16	   4.16 (0.00 pct)	   4.24 (1.92 pct)	   4.53 (8.89 pct)
>    32	   5.98 (0.00 pct)	   6.17 (3.17 pct)	   7.30 (22.07 pct)
>    64	   8.67 (0.00 pct)	   8.99 (3.69 pct)	  10.71 (23.52 pct)
>   128	  11.98 (0.00 pct)	  12.52 (4.50 pct)	  14.67 (22.45 pct)
>   256	  15.73 (0.00 pct)	  16.13 (2.54 pct)	  17.81 (13.22 pct)
>   512	  15.77 (0.00 pct)	  16.32 (3.48 pct)	  16.39 (3.93 pct)
> dbench power comparison:
> Clients:   acpi-cpufreq		   amd_pst+passive	   amd_pst+guided
>     1	   1.00 (0.00 pct)	   1.00 (0.00 pct)	   1.04 (4.00 pct)
>     2	   0.99 (0.00 pct)	   0.97 (-2.02 pct)	   1.02 (3.03 pct)
>     4	   0.98 (0.00 pct)	   0.98 (0.00 pct)	   1.02 (4.08 pct)
>     8	   0.98 (0.00 pct)	   0.99 (1.02 pct)	   1.02 (4.08 pct)
>    16	   0.99 (0.00 pct)	   1.00 (1.01 pct)	   1.04 (5.05 pct)
>    32	   1.02 (0.00 pct)	   1.02 (0.00 pct)	   1.07 (4.90 pct)
>    64	   1.05 (0.00 pct)	   1.05 (0.00 pct)	   1.11 (5.71 pct)
>   128	   1.08 (0.00 pct)	   1.08 (0.00 pct)	   1.15 (6.48 pct)
>   256	   1.12 (0.00 pct)	   1.12 (0.00 pct)	   1.20 (7.14 pct)
>   512	   1.18 (0.00 pct)	   1.17 (-0.84 pct)	   1.26 (6.77 pct)
> 
> ================ git-source comparisons ================
> git-source result comparison:
> Here results are throughput (compilations per 1000 sec)
> Threads:   acpi-cpufreq		   amd_pst+passive	   amd_pst+guided
>   192	   1.00 (0.00 pct)	   0.93 (-7.00 pct)	   1.00 (0.00 pct)
> git-source power comparison:
> Threads:   acpi-cpufreq		   amd_pst+passive	   amd_pst+guided
>   192	   1.00 (0.00 pct)	   1.00 (0.00 pct)	   0.96 (-4.00 pct)
> 
> ================ kernbench comparisons ================
> kernbench result comparison:
> Here results are throughput (compilations per 1000 sec)
> Load:	   acpi-cpufreq		   amd_pst+passive	   amd_pst+guided
> 32	   1.00 (0.00 pct)	   1.01 (1.00 pct)	   1.02 (2.00 pct)
> 48	   1.26 (0.00 pct)	   1.28 (1.58 pct)	   1.25 (-0.79 pct)
> 64	   1.39 (0.00 pct)	   1.47 (5.75 pct)	   1.43 (2.87 pct)
> 96	   1.48 (0.00 pct)	   1.50 (1.35 pct)	   1.49 (0.67 pct)
> 128	   1.29 (0.00 pct)	   1.32 (2.32 pct)	   1.33 (3.10 pct)
> 192	   1.17 (0.00 pct)	   1.20 (2.56 pct)	   1.21 (3.41 pct)
> 256	   1.17 (0.00 pct)	   1.18 (0.85 pct)	   1.20 (2.56 pct)
> 384	   1.16 (0.00 pct)	   1.17 (0.86 pct)	   1.21 (4.31 pct)
> kernbench power comparison:
> Clients:   acpi-cpufreq		   amd_pst+passive	   amd_pst+guided
>    32	   1.00 (0.00 pct)	   0.97 (-3.00 pct)	   1.00 (0.00 pct)
>    48	   0.87 (0.00 pct)	   0.81 (-6.89 pct)	   0.88 (1.14 pct)
>    64	   0.81 (0.00 pct)	   0.73 (-9.87 pct)	   0.77 (-4.93 pct)
>    96	   0.75 (0.00 pct)	   0.74 (-1.33 pct)	   0.75 (0.00 pct)
>   128	   0.83 (0.00 pct)	   0.79 (-4.81 pct)	   0.83 (0.00 pct)
>   192	   0.92 (0.00 pct)	   0.88 (-4.34 pct)	   0.92 (0.00 pct)
>   256	   0.92 (0.00 pct)	   0.88 (-4.34 pct)	   0.92 (0.00 pct)
>   384	   0.92 (0.00 pct)	   0.88 (-4.34 pct)	   0.92 (0.00 pct)
> 
> ================ tbench comparisons ================
> tbench result comparison:
> Here results are throughput (MB/s)
> Clients:   acpi-cpufreq		   amd_pst+passive	   amd_pst+guided
>     1	   1.00 (0.00 pct)	   0.70 (-30.00 pct)	   1.37 (37.00 pct)
>     2	   2.64 (0.00 pct)	   1.39 (-47.34 pct)	   2.70 (2.27 pct)
>     4	   4.89 (0.00 pct)	   2.75 (-43.76 pct)	   5.28 (7.97 pct)
>     8	   9.46 (0.00 pct)	   5.42 (-42.70 pct)	  10.22 (8.03 pct)
>    16	  19.05 (0.00 pct)	  10.42 (-45.30 pct)	  19.94 (4.67 pct)
>    32	  37.50 (0.00 pct)	  20.23 (-46.05 pct)	  36.87 (-1.68 pct)
>    64	  61.24 (0.00 pct)	  43.08 (-29.65 pct)	  62.96 (2.80 pct)
>   128	  67.16 (0.00 pct)	  69.08 (2.85 pct)	  67.34 (0.26 pct)
>   256	 154.59 (0.00 pct)	 162.33 (5.00 pct)	 156.78 (1.41 pct)
>   512	 154.02 (0.00 pct)	 156.74 (1.76 pct)	 153.48 (-0.35 pct)
> tbench power comparison:
> Clients:   acpi-cpufreq		   amd_pst+passive	   amd_pst+guided
>     1	   1.00 (0.00 pct)	   0.97 (-3.00 pct)	   1.08 (8.00 pct)
>     2	   1.04 (0.00 pct)	   0.97 (-6.73 pct)	   1.11 (6.73 pct)
>     4	   1.12 (0.00 pct)	   0.99 (-11.60 pct)	   1.18 (5.35 pct)
>     8	   1.25 (0.00 pct)	   1.04 (-16.80 pct)	   1.31 (4.80 pct)
>    16	   1.53 (0.00 pct)	   1.13 (-26.14 pct)	   1.58 (3.26 pct)
>    32	   2.01 (0.00 pct)	   1.36 (-32.33 pct)	   2.03 (0.99 pct)
>    64	   2.58 (0.00 pct)	   2.14 (-17.05 pct)	   2.61 (1.16 pct)
>   128	   2.80 (0.00 pct)	   2.81 (0.35 pct)	   2.81 (0.35 pct)
>   256	   3.39 (0.00 pct)	   3.43 (1.17 pct)	   3.42 (0.88 pct)
>   512	   3.44 (0.00 pct)	   3.44 (0.00 pct)	   3.44 (0.00 pct)
> 
> Note: this series is based on top of EPP v12 [3] series
> 
> Change log:
> 
> v6 -> v7:
> - Addressed comments by Ray
> - Reorder and rebase patches
> - Pick up Ack by Ray
> 
> v5 -> v6:
> - Don't return -EBUSY when changing to same mode
> 
> v4 -> v5:
> - Rebased on top of EPP v12 series
> - Addressed comments form Mario regarding documentation
> - Picked up RB flags from Mario and Bagas Sanjaya
> 
> v3 -> v4:
> - Fixed active mode low frequency issue reported by Peter Jung and Tor Vic
> - Documentation modification suggested by Bagas Sanjaya
> 
> v2 -> v3:
> - Addressed review comments form Mario.
> - Picked up RB tag from Mario.
> - Rebase on top of EPP v11 [3].
> 
> v1 -> v2:
> - Fix issue with shared mem systems.
> - Rebase on top of EPP series.
> 
> [1]: https://uefi.org/sites/default/files/resources/ACPI_6_3_final_Jan30.pdf
> [2]: https://lore.kernel.org/lkml/20221110175847.3098728-1-Perry.Yuan@amd.com/
> [3]: https://lore.kernel.org/linux-pm/20230131090016.3970625-1-perry.yuan@amd.com/
> 
> Wyes Karny (6):
>   acpi: cppc: Add min and max perf reg writing support
>   acpi: cppc: Add auto select register read/write support
>   Documentation: cpufreq: amd-pstate: Move amd_pstate param to
>     alphabetical order
>   cpufreq: amd-pstate: Add guided autonomous mode
>   cpufreq: amd-pstate: Add guided mode control support via sysfs
>   Documentation: cpufreq: amd-pstate: Update amd_pstate status sysfs for
>     guided
> 
>  .../admin-guide/kernel-parameters.txt         |  40 ++--
>  Documentation/admin-guide/pm/amd-pstate.rst   |  31 ++-
>  drivers/acpi/cppc_acpi.c                      | 121 +++++++++++-
>  drivers/cpufreq/amd-pstate.c                  | 177 +++++++++++++-----
>  include/acpi/cppc_acpi.h                      |  11 ++
>  include/linux/amd-pstate.h                    |   2 +
>  6 files changed, 302 insertions(+), 80 deletions(-)
> 

Hi Rafael,

Could you please apply these series into 6.3 or please kindly let us know
if you have any comments?

Thanks,
Ray
  

Hello.

On čtvrtek 16. února 2023 9:17:56 CET Wyes Karny wrote:
> >From ACPI spec[1] below 3 modes for CPPC can be defined:
> 1. Non autonomous: OS scaling governor specifies operating frequency/
>    performance level through `Desired Performance` register and platform
> follows that.
> 2. Guided autonomous: OS scaling governor specifies min and max
>    frequencies/ performance levels through `Minimum Performance` and
> `Maximum Performance` register, and platform can autonomously select an
> operating frequency in this range.
> 3. Fully autonomous: OS only hints (via EPP) to platform for the required
>    energy performance preference for the workload and platform autonomously
> scales the frequency.
> 
> Currently (1) is supported by amd_pstate as passive mode, and (3) is
> implemented by EPP support[2]. This change is to support (2).
> 
> In guided autonomous mode the min_perf is based on the input from the
> scaling governor. For example, in case of schedutil this value depends
> on the current utilization. And max_perf is set to max capacity.
> 
> To activate guided auto mode ``amd_pstate=guided`` command line
> parameter has to be passed in the kernel.
> 
> Below are the results (normalized) of benchmarks with this patch:
> System: Genoa 96C 192T
> Kernel: 6.2.0-rc2 + EPP v12 + patch
> Scaling governor: schedutil
> 
> ================ dbench comparisons ================
> dbench result comparison:
> Here results are throughput (MB/s)
> Clients:   acpi-cpufreq		   amd_pst+passive	   amd_pst+guided
>     1	   1.00 (0.00 pct)	   1.01 (1.00 pct)	   1.02 (2.00 pct)
>     2	   1.07 (0.00 pct)	   1.06 (-0.93 pct)	   1.07 (0.00 pct)
>     4	   1.68 (0.00 pct)	   1.70 (1.19 pct)	   1.72 (2.38 pct)
>     8	   2.61 (0.00 pct)	   2.68 (2.68 pct)	   2.76 (5.74 pct)
>    16	   4.16 (0.00 pct)	   4.24 (1.92 pct)	   4.53 (8.89 pct)
>    32	   5.98 (0.00 pct)	   6.17 (3.17 pct)	   7.30 (22.07 pct)
>    64	   8.67 (0.00 pct)	   8.99 (3.69 pct)	  10.71 (23.52 pct)
>   128	  11.98 (0.00 pct)	  12.52 (4.50 pct)	  14.67 (22.45 pct)
>   256	  15.73 (0.00 pct)	  16.13 (2.54 pct)	  17.81 (13.22 pct)
>   512	  15.77 (0.00 pct)	  16.32 (3.48 pct)	  16.39 (3.93 pct)
> dbench power comparison:
> Clients:   acpi-cpufreq		   amd_pst+passive	   amd_pst+guided
>     1	   1.00 (0.00 pct)	   1.00 (0.00 pct)	   1.04 (4.00 pct)
>     2	   0.99 (0.00 pct)	   0.97 (-2.02 pct)	   1.02 (3.03 pct)
>     4	   0.98 (0.00 pct)	   0.98 (0.00 pct)	   1.02 (4.08 pct)
>     8	   0.98 (0.00 pct)	   0.99 (1.02 pct)	   1.02 (4.08 pct)
>    16	   0.99 (0.00 pct)	   1.00 (1.01 pct)	   1.04 (5.05 pct)
>    32	   1.02 (0.00 pct)	   1.02 (0.00 pct)	   1.07 (4.90 pct)
>    64	   1.05 (0.00 pct)	   1.05 (0.00 pct)	   1.11 (5.71 pct)
>   128	   1.08 (0.00 pct)	   1.08 (0.00 pct)	   1.15 (6.48 pct)
>   256	   1.12 (0.00 pct)	   1.12 (0.00 pct)	   1.20 (7.14 pct)
>   512	   1.18 (0.00 pct)	   1.17 (-0.84 pct)	   1.26 (6.77 pct)
> 
> ================ git-source comparisons ================
> git-source result comparison:
> Here results are throughput (compilations per 1000 sec)
> Threads:   acpi-cpufreq		   amd_pst+passive	   amd_pst+guided
>   192	   1.00 (0.00 pct)	   0.93 (-7.00 pct)	   1.00 (0.00 pct)
> git-source power comparison:
> Threads:   acpi-cpufreq		   amd_pst+passive	   amd_pst+guided
>   192	   1.00 (0.00 pct)	   1.00 (0.00 pct)	   0.96 (-4.00 pct)
> 
> ================ kernbench comparisons ================
> kernbench result comparison:
> Here results are throughput (compilations per 1000 sec)
> Load:	   acpi-cpufreq		   amd_pst+passive	   amd_pst+guided
> 32	   1.00 (0.00 pct)	   1.01 (1.00 pct)	   1.02 (2.00 pct)
> 48	   1.26 (0.00 pct)	   1.28 (1.58 pct)	   1.25 (-0.79 pct)
> 64	   1.39 (0.00 pct)	   1.47 (5.75 pct)	   1.43 (2.87 pct)
> 96	   1.48 (0.00 pct)	   1.50 (1.35 pct)	   1.49 (0.67 pct)
> 128	   1.29 (0.00 pct)	   1.32 (2.32 pct)	   1.33 (3.10 pct)
> 192	   1.17 (0.00 pct)	   1.20 (2.56 pct)	   1.21 (3.41 pct)
> 256	   1.17 (0.00 pct)	   1.18 (0.85 pct)	   1.20 (2.56 pct)
> 384	   1.16 (0.00 pct)	   1.17 (0.86 pct)	   1.21 (4.31 pct)
> kernbench power comparison:
> Clients:   acpi-cpufreq		   amd_pst+passive	   amd_pst+guided
>    32	   1.00 (0.00 pct)	   0.97 (-3.00 pct)	   1.00 (0.00 pct)
>    48	   0.87 (0.00 pct)	   0.81 (-6.89 pct)	   0.88 (1.14 pct)
>    64	   0.81 (0.00 pct)	   0.73 (-9.87 pct)	   0.77 (-4.93 pct)
>    96	   0.75 (0.00 pct)	   0.74 (-1.33 pct)	   0.75 (0.00 pct)
>   128	   0.83 (0.00 pct)	   0.79 (-4.81 pct)	   0.83 (0.00 pct)
>   192	   0.92 (0.00 pct)	   0.88 (-4.34 pct)	   0.92 (0.00 pct)
>   256	   0.92 (0.00 pct)	   0.88 (-4.34 pct)	   0.92 (0.00 pct)
>   384	   0.92 (0.00 pct)	   0.88 (-4.34 pct)	   0.92 (0.00 pct)
> 
> ================ tbench comparisons ================
> tbench result comparison:
> Here results are throughput (MB/s)
> Clients:   acpi-cpufreq		   amd_pst+passive	   amd_pst+guided
>     1	   1.00 (0.00 pct)	   0.70 (-30.00 pct)	   1.37 (37.00 pct)
>     2	   2.64 (0.00 pct)	   1.39 (-47.34 pct)	   2.70 (2.27 pct)
>     4	   4.89 (0.00 pct)	   2.75 (-43.76 pct)	   5.28 (7.97 pct)
>     8	   9.46 (0.00 pct)	   5.42 (-42.70 pct)	  10.22 (8.03 pct)
>    16	  19.05 (0.00 pct)	  10.42 (-45.30 pct)	  19.94 (4.67 pct)
>    32	  37.50 (0.00 pct)	  20.23 (-46.05 pct)	  36.87 (-1.68 pct)
>    64	  61.24 (0.00 pct)	  43.08 (-29.65 pct)	  62.96 (2.80 pct)
>   128	  67.16 (0.00 pct)	  69.08 (2.85 pct)	  67.34 (0.26 pct)
>   256	 154.59 (0.00 pct)	 162.33 (5.00 pct)	 156.78 (1.41 pct)
>   512	 154.02 (0.00 pct)	 156.74 (1.76 pct)	 153.48 (-0.35 pct)
> tbench power comparison:
> Clients:   acpi-cpufreq		   amd_pst+passive	   amd_pst+guided
>     1	   1.00 (0.00 pct)	   0.97 (-3.00 pct)	   1.08 (8.00 pct)
>     2	   1.04 (0.00 pct)	   0.97 (-6.73 pct)	   1.11 (6.73 pct)
>     4	   1.12 (0.00 pct)	   0.99 (-11.60 pct)	   1.18 (5.35 pct)
>     8	   1.25 (0.00 pct)	   1.04 (-16.80 pct)	   1.31 (4.80 pct)
>    16	   1.53 (0.00 pct)	   1.13 (-26.14 pct)	   1.58 (3.26 pct)
>    32	   2.01 (0.00 pct)	   1.36 (-32.33 pct)	   2.03 (0.99 pct)
>    64	   2.58 (0.00 pct)	   2.14 (-17.05 pct)	   2.61 (1.16 pct)
>   128	   2.80 (0.00 pct)	   2.81 (0.35 pct)	   2.81 (0.35 pct)
>   256	   3.39 (0.00 pct)	   3.43 (1.17 pct)	   3.42 (0.88 pct)
>   512	   3.44 (0.00 pct)	   3.44 (0.00 pct)	   3.44 (0.00 pct)
> 
> Note: this series is based on top of EPP v12 [3] series
> 
> Change log:
> 
> v6 -> v7:
> - Addressed comments by Ray
> - Reorder and rebase patches
> - Pick up Ack by Ray
> 
> v5 -> v6:
> - Don't return -EBUSY when changing to same mode
> 
> v4 -> v5:
> - Rebased on top of EPP v12 series
> - Addressed comments form Mario regarding documentation
> - Picked up RB flags from Mario and Bagas Sanjaya
> 
> v3 -> v4:
> - Fixed active mode low frequency issue reported by Peter Jung and Tor Vic
> - Documentation modification suggested by Bagas Sanjaya
> 
> v2 -> v3:
> - Addressed review comments form Mario.
> - Picked up RB tag from Mario.
> - Rebase on top of EPP v11 [3].
> 
> v1 -> v2:
> - Fix issue with shared mem systems.
> - Rebase on top of EPP series.
> 
> [1]: https://uefi.org/sites/default/files/resources/ACPI_6_3_final_Jan30.pdf
> [2]: https://lore.kernel.org/lkml/20221110175847.3098728-1-Perry.Yuan@amd.com/
> [3]: https://lore.kernel.org/linux-pm/20230131090016.3970625-1-perry.yuan@amd.com/
> 
> Wyes Karny (6):
>   acpi: cppc: Add min and max perf reg writing support
>   acpi: cppc: Add auto select register read/write support
>   Documentation: cpufreq: amd-pstate: Move amd_pstate param to
>     alphabetical order
>   cpufreq: amd-pstate: Add guided autonomous mode
>   cpufreq: amd-pstate: Add guided mode control support via sysfs
>   Documentation: cpufreq: amd-pstate: Update amd_pstate status sysfs for
>     guided
> 
>  .../admin-guide/kernel-parameters.txt         |  40 ++--
>  Documentation/admin-guide/pm/amd-pstate.rst   |  31 ++-
>  drivers/acpi/cppc_acpi.c                      | 121 +++++++++++-
>  drivers/cpufreq/amd-pstate.c                  | 177 +++++++++++++-----
>  include/acpi/cppc_acpi.h                      |  11 ++
>  include/linux/amd-pstate.h                    |   2 +
>  6 files changed, 302 insertions(+), 80 deletions(-)

```
$ lscpu | grep 'Model name'
Model name:                      AMD Ryzen 9 5950X 16-Core Processor

$ cat /proc/cmdline
root=/dev/mapper/system threadirqs io_delay=none zswap.enabled=0 amd_pstate=guided quiet

$ sudo cpupower frequency-info
analyzing CPU 0:
driver: amd-pstate
CPUs which run at the same hardware frequency: 0
CPUs which need to have their frequency coordinated by software: 0
maximum transition latency: 20.0 us
hardware limits: 550 MHz - 5.08 GHz
available cpufreq governors: conservative ondemand userspace powersave performance schedutil
current policy: frequency should be within 550 MHz and 5.08 GHz.
The governor "schedutil" may decide which speed to use
within this range.
current CPU frequency: Unable to call hardware
current CPU frequency: 3.95 GHz (asserted by call to kernel)
boost state support:
Supported: yes
Active: yes
AMD PSTATE Highest Performance: 166. Maximum Frequency: 5.08 GHz.
AMD PSTATE Nominal Performance: 111. Nominal Frequency: 3.40 GHz.
AMD PSTATE Lowest Non-linear Performance: 57. Lowest Non-linear Frequency: 1.74 GHz.
AMD PSTATE Lowest Performance: 19. Lowest Frequency: 550 MHz.
```

Tested-by: Oleksandr Natalenko <oleksandr@natalenko.name>

Thank you.