Re: [PATCH v3 3/5] acpi: Introduce new function callback for _OSC

["Wilczynski, Michal" <michal.wilczynski@intel.com>]

Hi,
Thanks for the review !

On 6/29/2023 1:04 PM, Rafael J. Wysocki wrote:
> I would just say "Introduce acpi_processor_osc()" in the subject and
> then explain its role in the changelog.

Sure,

>
> On Tue, Jun 13, 2023 at 6:12 PM Michal Wilczynski
> <michal.wilczynski@intel.com> wrote:
>> Currently in ACPI code _OSC method is already used for workaround
>> introduced in commit a21211672c9a ("ACPI / processor: Request native
>> thermal interrupt handling via _OSC"). Create new function, similar to
>> already existing acpi_hwp_native_thermal_lvt_osc(). Call new function
>> acpi_processor_osc(). Make this function fulfill the purpose previously
>> fulfilled by the workaround plus convey OSPM processor capabilities
>> with it by setting correct processor capability bits.
>>
>> Suggested-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
>> Signed-off-by: Michal Wilczynski <michal.wilczynski@intel.com>
>> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
>> ---
>>  arch/x86/include/asm/acpi.h   |  3 +++
>>  drivers/acpi/acpi_processor.c | 43 ++++++++++++++++++++++++++++++++++-
>>  include/acpi/pdc_intel.h      |  1 +
>>  3 files changed, 46 insertions(+), 1 deletion(-)
>>
>> diff --git a/arch/x86/include/asm/acpi.h b/arch/x86/include/asm/acpi.h
>> index 6a498d1781e7..6c25ce2dad18 100644
>> --- a/arch/x86/include/asm/acpi.h
>> +++ b/arch/x86/include/asm/acpi.h
>> @@ -112,6 +112,9 @@ static inline void arch_acpi_set_proc_cap_bits(u32 *cap)
>>         if (cpu_has(c, X86_FEATURE_ACPI))
>>                 *cap |= ACPI_PDC_T_FFH;
>>
>> +       if (cpu_has(c, X86_FEATURE_HWP))
>> +               *cap |= ACPI_PDC_COLLAB_PROC_PERF;
>> +
>>         /*
>>          * If mwait/monitor is unsupported, C2/C3_FFH will be disabled
>>          */
>> diff --git a/drivers/acpi/acpi_processor.c b/drivers/acpi/acpi_processor.c
>> index 8c5d0295a042..0de0b05b6f53 100644
>> --- a/drivers/acpi/acpi_processor.c
>> +++ b/drivers/acpi/acpi_processor.c
>> @@ -591,13 +591,54 @@ void __init processor_dmi_check(void)
>>         dmi_check_system(processor_idle_dmi_table);
>>  }
>>
>> +/* vendor specific UUID indicating an Intel platform */
>> +static u8 sb_uuid_str[] = "4077A616-290C-47BE-9EBD-D87058713953";
>>  static bool acpi_hwp_native_thermal_lvt_set;
>> +static acpi_status __init acpi_processor_osc(acpi_handle handle, u32 lvl,
>> +                                            void *context, void **rv)
>> +{
>> +       u32 capbuf[2] = {};
>> +       acpi_status status;
>> +       struct acpi_osc_context osc_context = {
>> +               .uuid_str = sb_uuid_str,
>> +               .rev = 1,
>> +               .cap.length = 8,
>> +               .cap.pointer = capbuf,
>> +       };
>> +
>> +       if (processor_physically_present(handle) == false)
> if (!processor_physically_present(handle))

Sure,

>
>> +               return AE_OK;
>> +
>> +       arch_acpi_set_proc_cap_bits(&capbuf[OSC_SUPPORT_DWORD]);
>> +
>> +       if (boot_option_idle_override == IDLE_NOMWAIT)
>> +               capbuf[OSC_SUPPORT_DWORD] &=
>> +                       ~(ACPI_PDC_C_C2C3_FFH | ACPI_PDC_C_C1_FFH);
>> +
>> +       status = acpi_run_osc(handle, &osc_context);
>> +       if (ACPI_FAILURE(status))
>> +               return status;
>> +
>> +       if (osc_context.ret.pointer && osc_context.ret.length > 1) {
>> +               u32 *capbuf_ret = osc_context.ret.pointer;
>> +
>> +               if (!acpi_hwp_native_thermal_lvt_set &&
>> +                   capbuf_ret[1] & ACPI_PDC_COLLAB_PROC_PERF) {
> Checking it in capbuf_ret[] if it was not set in capbuf[] is sort of
> questionable.
> Note that acpi_hwp_native_thermal_lvt_osc() sets it in capbuf[] before
> calling acpi_run_osc().

We can add condition before checking capbuf_ret i.e

if (capbuf[OSC_SUPPORT_DWORD] & ACPI_PDC_COLLAB_PROC_PERF &&
    osc_context.ret.pointer && osc_context.ret.length > 1)
 

>
>> +                       acpi_handle_info(handle,
>> +                                        "_OSC native thermal LVT Acked\n");
>> +                       acpi_hwp_native_thermal_lvt_set = true;
>> +               }
>> +       }
>> +       kfree(osc_context.ret.pointer);
>> +
>> +       return AE_OK;
>> +}
>> +
>>  static acpi_status __init acpi_hwp_native_thermal_lvt_osc(acpi_handle handle,
>>                                                           u32 lvl,
>>                                                           void *context,
>>                                                           void **rv)
>>  {
>> -       u8 sb_uuid_str[] = "4077A616-290C-47BE-9EBD-D87058713953";
>>         u32 capbuf[2];
>>         struct acpi_osc_context osc_context = {
>>                 .uuid_str = sb_uuid_str,
>> diff --git a/include/acpi/pdc_intel.h b/include/acpi/pdc_intel.h
>> index 967c552d1cd3..9427f639287f 100644
>> --- a/include/acpi/pdc_intel.h
>> +++ b/include/acpi/pdc_intel.h
>> @@ -16,6 +16,7 @@
>>  #define ACPI_PDC_C_C1_FFH              (0x0100)
>>  #define ACPI_PDC_C_C2C3_FFH            (0x0200)
>>  #define ACPI_PDC_SMP_P_HWCOORD         (0x0800)
>> +#define ACPI_PDC_COLLAB_PROC_PERF      (0x1000)
> I would call this ACPI_OSC_COLLAB_PROC_PERF to avoid confusion.
>
> It may also be a good idea to introduce ACPI_OSC_ symbols to replace
> the existing ACPI_PDC_ ones (with the same values, respectively) and
> get rid of the latter later.

Sure I can do that, most likely in a separate commit preceeding this one, so
it's easier to explain and review,

>
>>  #define ACPI_PDC_EST_CAPABILITY_SMP    (ACPI_PDC_SMP_C1PT | \
>>                                          ACPI_PDC_C_C1_HALT | \
>> --