mbox series

[v4,0/9] Prefer using _OSC method over deprecated _PDC

Message ID 20230710140337.1434060-1-michal.wilczynski@intel.com
Headers show
Series Prefer using _OSC method over deprecated _PDC | expand

Message

Michal Wilczynski July 10, 2023, 2:03 p.m. UTC
ACPI 3.0 introduced a new Operating System Capabilities _OSC control
method. This method is similar to _PDC, which was marked as deprecated
in ACPI 3.0.

Prefer using _OSC method over deprecated _PDC in the acpi_bus_init(). In
case of the failure of the _OSC, try using _PDC as a fallback.

Testing done:
Tested on physical server with BIOS implementing _OSC methods. In this
case acpi_processor_osc() was executed for each CPU core. acpi_run_osc()
returned success indicating that _OSC method succeeded.

Tested on qemu VM to check whether the code would work on a SeaBios (the
default for qemu, doesn't support _OSC methods, or _PDC). This way I was
able to see how code behaves in case BIOS doesn't implement _OSC. In
that case the function
acpi_run_osc() returned failure, which propagated all the way up to
acpi_early_processor_osc(). The logic responsible for triggering _PDC
execution was triggered correctly.

Tested this using debug messages with printk.

v4:
 - move setting processor capabilities bits into arch code
 - move workaround for mwait to acpi/x86 directory
 - rename ACPI_PDC* constants to more generic ACPI_PROC_CAP*
 - introduce new function acpi_early_processor_control_setup()

v3:
 - split into more commits to make review easier
 - changed "_UID" to METHOD_NAME_UID
 - changed hard-coded constant to ACPI_PDC_COLLAB_PROC_PERF
 - added Suggested-by tags
 - fixed style issues
 - fixed whitespaces
 - refactored code
v2:
 - fixed compilation issues on ia64 and arm

Michal Wilczynski (9):
  acpi: Move mwait quirk out of acpi_processor.c
  acpi: Move processor_physically_present() to acpi_processor.c
  acpi: Refactor arch_acpi_set_pdc_bits()
  acpi: Rename ACPI_PDC constants
  acpi: Clear C_C2C3_FFH and C_C1_FFH in arch_acpi_set_proc_cap_bits()
  acpi: Move setting CAP_SMP_T_SWCOORD to arch_acpi_set_proc_cap_bits()
  acpi: Introduce acpi_processor_osc()
  acpi: Use _OSC method to convey processor OSPM capabilities
  acpi: Remove acpi_hwp_native_thermal_lvt_osc()

 arch/ia64/include/asm/acpi.h  |   6 +-
 arch/x86/include/asm/acpi.h   |  24 ++++---
 arch/x86/xen/enlighten_pv.c   |   8 +--
 drivers/acpi/acpi_processor.c | 121 +++++++++++++++++++++++++---------
 drivers/acpi/bus.c            |   5 +-
 drivers/acpi/internal.h       |  10 ++-
 drivers/acpi/processor_pdc.c  |  97 +--------------------------
 drivers/acpi/x86/utils.c      |  35 ++++++++++
 include/acpi/pdc_intel.h      |  36 ----------
 include/acpi/proc_cap_intel.h |  40 +++++++++++
 10 files changed, 194 insertions(+), 188 deletions(-)
 delete mode 100644 include/acpi/pdc_intel.h
 create mode 100644 include/acpi/proc_cap_intel.h

Comments

Rafael J. Wysocki July 14, 2023, 4:12 p.m. UTC | #1
On Mon, Jul 10, 2023 at 4:06 PM Michal Wilczynski
<michal.wilczynski@intel.com> wrote:
>
> ACPI 3.0 introduced a new Operating System Capabilities _OSC control
> method. This method is similar to _PDC, which was marked as deprecated
> in ACPI 3.0.
>
> Prefer using _OSC method over deprecated _PDC in the acpi_bus_init(). In
> case of the failure of the _OSC, try using _PDC as a fallback.
>
> Testing done:
> Tested on physical server with BIOS implementing _OSC methods. In this
> case acpi_processor_osc() was executed for each CPU core. acpi_run_osc()
> returned success indicating that _OSC method succeeded.
>
> Tested on qemu VM to check whether the code would work on a SeaBios (the
> default for qemu, doesn't support _OSC methods, or _PDC). This way I was
> able to see how code behaves in case BIOS doesn't implement _OSC. In
> that case the function
> acpi_run_osc() returned failure, which propagated all the way up to
> acpi_early_processor_osc(). The logic responsible for triggering _PDC
> execution was triggered correctly.
>
> Tested this using debug messages with printk.
>
> v4:
>  - move setting processor capabilities bits into arch code
>  - move workaround for mwait to acpi/x86 directory
>  - rename ACPI_PDC* constants to more generic ACPI_PROC_CAP*
>  - introduce new function acpi_early_processor_control_setup()
>
> v3:
>  - split into more commits to make review easier
>  - changed "_UID" to METHOD_NAME_UID
>  - changed hard-coded constant to ACPI_PDC_COLLAB_PROC_PERF
>  - added Suggested-by tags
>  - fixed style issues
>  - fixed whitespaces
>  - refactored code
> v2:
>  - fixed compilation issues on ia64 and arm
>
> Michal Wilczynski (9):
>   acpi: Move mwait quirk out of acpi_processor.c
>   acpi: Move processor_physically_present() to acpi_processor.c
>   acpi: Refactor arch_acpi_set_pdc_bits()
>   acpi: Rename ACPI_PDC constants
>   acpi: Clear C_C2C3_FFH and C_C1_FFH in arch_acpi_set_proc_cap_bits()
>   acpi: Move setting CAP_SMP_T_SWCOORD to arch_acpi_set_proc_cap_bits()
>   acpi: Introduce acpi_processor_osc()
>   acpi: Use _OSC method to convey processor OSPM capabilities
>   acpi: Remove acpi_hwp_native_thermal_lvt_osc()

I have made a number of changes to the patches (edited subjects,
rewrote changelogs, fixed up whitespace in a few places, changed the
return value of acpi_early_processor_osc() to bool and made it static
etc.) and tentatively queued them up for 6.6.  Please see the
bleeding-edge branch of linux-pm.git.

I have made sure that the series will still compile at least on
x86-64, but testing it again would be appreciated.

Thanks!
Michal Wilczynski July 17, 2023, 10:49 a.m. UTC | #2
On 7/14/2023 6:12 PM, Rafael J. Wysocki wrote:
> On Mon, Jul 10, 2023 at 4:06 PM Michal Wilczynski
> <michal.wilczynski@intel.com> wrote:
>> ACPI 3.0 introduced a new Operating System Capabilities _OSC control
>> method. This method is similar to _PDC, which was marked as deprecated
>> in ACPI 3.0.
>>
>> Prefer using _OSC method over deprecated _PDC in the acpi_bus_init(). In
>> case of the failure of the _OSC, try using _PDC as a fallback.
>>
>> Testing done:
>> Tested on physical server with BIOS implementing _OSC methods. In this
>> case acpi_processor_osc() was executed for each CPU core. acpi_run_osc()
>> returned success indicating that _OSC method succeeded.
>>
>> Tested on qemu VM to check whether the code would work on a SeaBios (the
>> default for qemu, doesn't support _OSC methods, or _PDC). This way I was
>> able to see how code behaves in case BIOS doesn't implement _OSC. In
>> that case the function
>> acpi_run_osc() returned failure, which propagated all the way up to
>> acpi_early_processor_osc(). The logic responsible for triggering _PDC
>> execution was triggered correctly.
>>
>> Tested this using debug messages with printk.
>>
>> v4:
>>  - move setting processor capabilities bits into arch code
>>  - move workaround for mwait to acpi/x86 directory
>>  - rename ACPI_PDC* constants to more generic ACPI_PROC_CAP*
>>  - introduce new function acpi_early_processor_control_setup()
>>
>> v3:
>>  - split into more commits to make review easier
>>  - changed "_UID" to METHOD_NAME_UID
>>  - changed hard-coded constant to ACPI_PDC_COLLAB_PROC_PERF
>>  - added Suggested-by tags
>>  - fixed style issues
>>  - fixed whitespaces
>>  - refactored code
>> v2:
>>  - fixed compilation issues on ia64 and arm
>>
>> Michal Wilczynski (9):
>>   acpi: Move mwait quirk out of acpi_processor.c
>>   acpi: Move processor_physically_present() to acpi_processor.c
>>   acpi: Refactor arch_acpi_set_pdc_bits()
>>   acpi: Rename ACPI_PDC constants
>>   acpi: Clear C_C2C3_FFH and C_C1_FFH in arch_acpi_set_proc_cap_bits()
>>   acpi: Move setting CAP_SMP_T_SWCOORD to arch_acpi_set_proc_cap_bits()
>>   acpi: Introduce acpi_processor_osc()
>>   acpi: Use _OSC method to convey processor OSPM capabilities
>>   acpi: Remove acpi_hwp_native_thermal_lvt_osc()
> I have made a number of changes to the patches (edited subjects,
> rewrote changelogs, fixed up whitespace in a few places, changed the
> return value of acpi_early_processor_osc() to bool and made it static
> etc.) and tentatively queued them up for 6.6.  Please see the
> bleeding-edge branch of linux-pm.git.
>
> I have made sure that the series will still compile at least on
> x86-64, but testing it again would be appreciated.
>
> Thanks!

Thanks, will re-test on linux-pm