Use the info in the metadata to decide if the data source feature is
supported. The CPU MIDR must be in the CPU list for the common data
source encoding.

For the metadata version 1, it doesn't include info for MIDR. In this
case, due to absent info for making decision, print out warning to
remind users to upgrade tool and returns false.

Signed-off-by: Leo Yan <leo.yan@arm.com>
---
 tools/perf/util/arm-spe.c | 67 +++++++++++++++++++++++++++++++++++++--
 1 file changed, 64 insertions(+), 3 deletions(-)

diff --git a/tools/perf/util/arm-spe.c b/tools/perf/util/arm-spe.c
index 587943b6bdb8..9221b2f66bbe 100644
--- a/tools/perf/util/arm-spe.c
+++ b/tools/perf/util/arm-spe.c
@@ -278,6 +278,20 @@ static int arm_spe_set_tid(struct arm_spe_queue *speq, pid_t tid)
 	return 0;
 }
 
+static u64 *arm_spe__get_metadata_by_cpu(struct arm_spe *spe, u64 cpu)
+{
+	u64 i;
+
+	if (!spe->metadata)
+		return NULL;
+
+	for (i = 0; i < spe->metadata_nr_cpu; i++)
+		if (spe->metadata[i][ARM_SPE_CPU] == cpu)
+			return spe->metadata[i];
+
+	return NULL;
+}
+
 static struct simd_flags arm_spe__synth_simd_flags(const struct arm_spe_record *record)
 {
 	struct simd_flags simd_flags = {};
@@ -520,10 +534,57 @@ static void arm_spe__synth_memory_level(const struct arm_spe_record *record,
 		data_src->mem_lvl |= PERF_MEM_LVL_REM_CCE1;
 }
 
-static u64 arm_spe__synth_data_source(const struct arm_spe_record *record, u64 midr)
+static bool arm_spe__is_common_ds_encoding(struct arm_spe_queue *speq)
+{
+	struct arm_spe *spe = speq->spe;
+	bool is_in_cpu_list;
+	u64 *metadata = NULL;
+	u64 midr = 0;
+
+	/*
+	 * Metadata version 1 doesn't contain any info for MIDR.
+	 * Simply return false in this case.
+	 */
+	if (spe->metadata_ver == 1) {
+		pr_warning_once("The data file contains metadata version 1, "
+				"which is absent the info for data source. "
+				"Please upgrade the tool to record data.\n");
+		return false;
+	}
+
+	/* CPU ID is -1 for per-thread mode */
+	if (speq->cpu < 0) {
+		/*
+		 * On the heterogeneous system, due to CPU ID is -1,
+		 * cannot confirm the data source packet is supported.
+		 */
+		if (!spe->is_homogeneous)
+			return false;
+
+		/* In homogeneous system, simply use CPU0's metadata */
+		if (spe->metadata)
+			metadata = spe->metadata[0];
+	} else {
+		metadata = arm_spe__get_metadata_by_cpu(spe, speq->cpu);
+	}
+
+	if (!metadata)
+		return false;
+
+	midr = metadata[ARM_SPE_CPU_MIDR];
+
+	is_in_cpu_list = is_midr_in_range_list(midr, common_ds_encoding_cpus);
+	if (is_in_cpu_list)
+		return true;
+	else
+		return false;
+}
+
+static u64 arm_spe__synth_data_source(struct arm_spe_queue *speq,
+				      const struct arm_spe_record *record)
 {
 	union perf_mem_data_src	data_src = { .mem_op = PERF_MEM_OP_NA };
-	bool is_common = is_midr_in_range_list(midr, common_ds_encoding_cpus);
+	bool is_common = arm_spe__is_common_ds_encoding(speq);
 
 	if (record->op & ARM_SPE_OP_LD)
 		data_src.mem_op = PERF_MEM_OP_LOAD;
@@ -556,7 +617,7 @@ static int arm_spe_sample(struct arm_spe_queue *speq)
 	u64 data_src;
 	int err;
 
-	data_src = arm_spe__synth_data_source(record, spe->midr);
+	data_src = arm_spe__synth_data_source(speq, record);
 
 	if (spe->sample_flc) {
 		if (record->type & ARM_SPE_L1D_MISS) {
-- 
2.34.1

On 03/10/2024 7:53 pm, Leo Yan wrote:
> Use the info in the metadata to decide if the data source feature is
> supported. The CPU MIDR must be in the CPU list for the common data
> source encoding.
> 
> For the metadata version 1, it doesn't include info for MIDR. In this
> case, due to absent info for making decision, print out warning to
> remind users to upgrade tool and returns false.
> 
> Signed-off-by: Leo Yan <leo.yan@arm.com>
> ---
>   tools/perf/util/arm-spe.c | 67 +++++++++++++++++++++++++++++++++++++--
>   1 file changed, 64 insertions(+), 3 deletions(-)
> 
> diff --git a/tools/perf/util/arm-spe.c b/tools/perf/util/arm-spe.c
> index 587943b6bdb8..9221b2f66bbe 100644
> --- a/tools/perf/util/arm-spe.c
> +++ b/tools/perf/util/arm-spe.c
> @@ -278,6 +278,20 @@ static int arm_spe_set_tid(struct arm_spe_queue *speq, pid_t tid)
>   	return 0;
>   }
>   
> +static u64 *arm_spe__get_metadata_by_cpu(struct arm_spe *spe, u64 cpu)
> +{
> +	u64 i;
> +
> +	if (!spe->metadata)
> +		return NULL;
> +
> +	for (i = 0; i < spe->metadata_nr_cpu; i++)
> +		if (spe->metadata[i][ARM_SPE_CPU] == cpu)
> +			return spe->metadata[i];
> +
> +	return NULL;
> +}
> +
>   static struct simd_flags arm_spe__synth_simd_flags(const struct arm_spe_record *record)
>   {
>   	struct simd_flags simd_flags = {};
> @@ -520,10 +534,57 @@ static void arm_spe__synth_memory_level(const struct arm_spe_record *record,
>   		data_src->mem_lvl |= PERF_MEM_LVL_REM_CCE1;
>   }
>   
> -static u64 arm_spe__synth_data_source(const struct arm_spe_record *record, u64 midr)
> +static bool arm_spe__is_common_ds_encoding(struct arm_spe_queue *speq)
> +{
> +	struct arm_spe *spe = speq->spe;
> +	bool is_in_cpu_list;
> +	u64 *metadata = NULL;
> +	u64 midr = 0;
> +
> +	/*
> +	 * Metadata version 1 doesn't contain any info for MIDR.
> +	 * Simply return false in this case.
> +	 */
> +	if (spe->metadata_ver == 1) {
> +		pr_warning_once("The data file contains metadata version 1, "
> +				"which is absent the info for data source. "
> +				"Please upgrade the tool to record data.\n");
> +		return false;
> +	}
> +
> +	/* CPU ID is -1 for per-thread mode */
> +	if (speq->cpu < 0) {
> +		/*
> +		 * On the heterogeneous system, due to CPU ID is -1,
> +		 * cannot confirm the data source packet is supported.
> +		 */
> +		if (!spe->is_homogeneous)
> +			return false;

Technically you could look at timestamps and context switches to find 
the CPU for non-homogeneous per-thread mode. But it's such an edge case 
I'm not sure it's even worth leaving a TODO for.

On 10/10/24 14:53, James Clark wrote:

[...]

>> +static bool arm_spe__is_common_ds_encoding(struct arm_spe_queue *speq)
>> +{
>> +     struct arm_spe *spe = speq->spe;
>> +     bool is_in_cpu_list;
>> +     u64 *metadata = NULL;
>> +     u64 midr = 0;
>> +
>> +     /*
>> +      * Metadata version 1 doesn't contain any info for MIDR.
>> +      * Simply return false in this case.
>> +      */
>> +     if (spe->metadata_ver == 1) {
>> +             pr_warning_once("The data file contains metadata version 1, "
>> +                             "which is absent the info for data source. "
>> +                             "Please upgrade the tool to record data.\n");
>> +             return false;
>> +     }
>> +
>> +     /* CPU ID is -1 for per-thread mode */
>> +     if (speq->cpu < 0) {
>> +             /*
>> +              * On the heterogeneous system, due to CPU ID is -1,
>> +              * cannot confirm the data source packet is supported.
>> +              */
>> +             if (!spe->is_homogeneous)
>> +                     return false;
> 
> Technically you could look at timestamps and context switches to find
> the CPU for non-homogeneous per-thread mode. But it's such an edge case
> I'm not sure it's even worth leaving a TODO for.

Good point. Let’s bear the idea in mind in case we need it later.

Thanks,
Leo