Re: [PATCH] perf arm-spe: Add support for SPE Data Source packet on AmpereOne

[Ilkka Koskinen <ilkka@os.amperecomputing.com>]

Hi Leo,

On Fri, 25 Oct 2024, Leo Yan wrote:
> On Thu, Oct 24, 2024 at 11:30:35PM +0000, Ilkka Koskinen wrote:
>>
>> Decode SPE Data Source packets on AmpereOne. The field is IMPDEF.
>>
>> Signed-off-by: Ilkka Koskinen <ilkka@os.amperecomputing.com>
>> ---
>>  .../util/arm-spe-decoder/arm-spe-decoder.h    |  9 +++
>>  tools/perf/util/arm-spe.c                     | 61 +++++++++++++++++++
>>  2 files changed, 70 insertions(+)
>>
>> diff --git a/tools/perf/util/arm-spe-decoder/arm-spe-decoder.h b/tools/perf/util/arm-spe-decoder/arm-spe-decoder.h
>> index 1443c28545a9..e4115b1e92b2 100644
>> --- a/tools/perf/util/arm-spe-decoder/arm-spe-decoder.h
>> +++ b/tools/perf/util/arm-spe-decoder/arm-spe-decoder.h
>> @@ -67,6 +67,15 @@ enum arm_spe_neoverse_data_source {
>>         ARM_SPE_NV_DRAM          = 0xe,
>>  };
>>
>> +enum arm_spe_ampereone_data_source {
>> +       ARM_SPE_AMPEREONE_LOCAL_CHIP_CACHE_OR_DEVICE    = 0x0,
>> +       ARM_SPE_AMPEREONE_SLC                           = 0x3,
>> +       ARM_SPE_AMPEREONE_REMOTE_CHIP_CACHE             = 0x5,
>> +       ARM_SPE_AMPEREONE_DDR                           = 0x7,
>> +       ARM_SPE_AMPEREONE_L1D                           = 0x8,
>> +       ARM_SPE_AMPEREONE_L2D                           = 0x9,
>> +};
>> +
>>  struct arm_spe_record {
>>         enum arm_spe_sample_type type;
>>         int err;
>> diff --git a/tools/perf/util/arm-spe.c b/tools/perf/util/arm-spe.c
>> index 138ffc71b32d..04bd21ad7ea8 100644
>> --- a/tools/perf/util/arm-spe.c
>> +++ b/tools/perf/util/arm-spe.c
>> @@ -515,10 +515,69 @@ static void arm_spe__synth_data_source_generic(const struct arm_spe_record *reco
>>                 data_src->mem_lvl |= PERF_MEM_LVL_REM_CCE1;
>>  }
>>
>> +static const struct midr_range ampereone_source_spe[] = {
>> +       MIDR_ALL_VERSIONS(MIDR_AMPERE1A),
>> +       {},
>> +};
>> +
>> +static void arm_spe__synth_data_source_ampereone(const struct arm_spe_record *record,
>> +                                                union perf_mem_data_src *data_src,
>> +                                                u64 midr)
>> +{
>> +       if (!is_midr_in_range_list(midr, ampereone_source_spe)) {
>> +               arm_spe__synth_data_source_generic(record, data_src);
>> +               return;
>> +       }
>
> With James' suggestion, I don't think here need to check the CPU
> variant again.  All generic data source generating should run in the
> arm_spe__synth_data_source() function.

Yep, checking the implementor ID was just wrong and unnecessary.
I fix that.

>
>> +
>> +       if (record->op & ARM_SPE_OP_ST) {
>> +               data_src->mem_lvl = PERF_MEM_LVL_NA;
>> +               data_src->mem_lvl_num = PERF_MEM_LVLNUM_NA;
>> +               data_src->mem_snoop = PERF_MEM_SNOOP_NA;
>> +               return;
>> +       }
>> +
>> +       switch (record->source) {
>> +       case ARM_SPE_AMPEREONE_LOCAL_CHIP_CACHE_OR_DEVICE:
>> +               data_src->mem_lvl = PERF_MEM_LVL_L2 | PERF_MEM_LVL_HIT;
>> +               data_src->mem_lvl_num = PERF_MEM_LVLNUM_L2;
>> +               data_src->mem_snoopx = PERF_MEM_SNOOPX_PEER;
>> +               break;
>> +       case ARM_SPE_AMPEREONE_SLC:
>> +               data_src->mem_lvl = PERF_MEM_LVL_L3 | PERF_MEM_LVL_HIT;
>> +               data_src->mem_lvl_num = PERF_MEM_LVLNUM_L3;
>> +               data_src->mem_snoop = PERF_MEM_SNOOP_HIT;
>> +               break;
>> +       case ARM_SPE_AMPEREONE_REMOTE_CHIP_CACHE:
>> +               data_src->mem_lvl = PERF_MEM_LVL_REM_CCE1;
>> +               data_src->mem_lvl_num = PERF_MEM_LVLNUM_ANY_CACHE;
>> +               data_src->mem_remote = PERF_MEM_REMOTE_REMOTE;
>> +               data_src->mem_snoopx = PERF_MEM_SNOOPX_PEER;
>> +               break;
>> +       case ARM_SPE_AMPEREONE_DDR:
>> +               data_src->mem_lvl = PERF_MEM_LVL_LOC_RAM | PERF_MEM_LVL_HIT;
>> +               data_src->mem_lvl_num = PERF_MEM_LVLNUM_RAM;
>> +               data_src->mem_snoop = PERF_MEM_SNOOP_NONE;
>> +               break;
>> +       case ARM_SPE_AMPEREONE_L1D:
>> +               data_src->mem_lvl = PERF_MEM_LVL_L1 | PERF_MEM_LVL_HIT;
>> +               data_src->mem_lvl_num = PERF_MEM_LVLNUM_L1;
>> +               data_src->mem_snoop = PERF_MEM_SNOOP_NONE;
>> +               break;
>> +       case ARM_SPE_AMPEREONE_L2D:
>> +               data_src->mem_lvl = PERF_MEM_LVL_L2 | PERF_MEM_LVL_HIT;
>> +               data_src->mem_lvl_num = PERF_MEM_LVLNUM_L2;
>> +               data_src->mem_snoop = PERF_MEM_SNOOP_NONE;
>> +               break;
>
> We have another way to do this.  If convert the SoC specific data source
> to common data source values, e.g.
>
>  ARM_SPE_AMPEREONE_LOCAL_CHIP_CACHE_OR_DEVICE -> ARM_SPE_NV_PEER_CORE
>  ARM_SPE_AMPEREONE_SLC -> ARM_SPE_NV_SYS_CACHE
>  ARM_SPE_AMPEREONE_REMOTE_CHIP_CACHE -> ARM_SPE_NV_REMOTE
>  ARM_SPE_AMPEREONE_DDR -> ARM_SPE_NV_DRAM
>  ...
>
> Then we don't need to maintain two functions with almost same setting.
>
> I have no strong opinion for this. A dedicated function for Ampere CPU
> might give a bit flexiblity for later tweaking. It is up to you.

Let me think about it and see how it would look like.

>
> Last thing, please work on the the latest perf-tools-next branch:
>
>  https://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools-next.git
>  branch: perf-tools-next
>
> Recently we have Arm SPE data source refactoring, please rebase on it.

Uh, for some reason I rebased it on top of Will's arm64 tree. Sorry about 
that.

Cheers, Ilkka

>
> Thanks,
> Leo
>
>> +       default:
>> +               break;
>> +       }
>> +}
>> +
>>  static u64 arm_spe__synth_data_source(const struct arm_spe_record *record, u64 midr)
>>  {
>>         union perf_mem_data_src data_src = { .mem_op = PERF_MEM_OP_NA };
>>         bool is_neoverse = is_midr_in_range_list(midr, neoverse_spe);
>> +       bool is_ampereone = (read_cpuid_implementor() == ARM_CPU_IMP_AMPERE);
>>
>>         if (record->op & ARM_SPE_OP_LD)
>>                 data_src.mem_op = PERF_MEM_OP_LOAD;
>> @@ -529,6 +588,8 @@ static u64 arm_spe__synth_data_source(const struct arm_spe_record *record, u64 m
>>
>>         if (is_neoverse)
>>                 arm_spe__synth_data_source_neoverse(record, &data_src);
>> +       else if (is_ampereone)
>> +               arm_spe__synth_data_source_ampereone(record, &data_src, midr);
>>         else
>>                 arm_spe__synth_data_source_generic(record, &data_src);
>>
>> --
>> 2.47.0
>>
>>
>