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* [PATCH v2] drivers/perf: hisi: Simplify hisi_read_sccl_and_ccl_id and its comment
@ 2019-11-14  0:57 Shaokun Zhang
  2019-11-14  9:50 ` John Garry
  2019-11-14 13:37 ` Mark Rutland
  0 siblings, 2 replies; 3+ messages in thread
From: Shaokun Zhang @ 2019-11-14  0:57 UTC (permalink / raw)
  To: linux-arm-kernel; +Cc: Shaokun Zhang, Mark Rutland, John Garry, Will Deacon

hisi_read_sccl_and_ccl_id is not readable and its comment is a little
confused, so simplify the function and its comment as Mark's suggestion.

Cc: John Garry <john.garry@huawei.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will@kernel.org>
Suggested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Shaokun Zhang <zhangshaokun@hisilicon.com>
---
ChangeLog from V2:
    Address John's comment: remove the confusing 'Kunpeng 920' comment who
has two types.

 drivers/perf/hisilicon/hisi_uncore_pmu.c | 58 ++++++++++++++++++--------------
 1 file changed, 32 insertions(+), 26 deletions(-)

diff --git a/drivers/perf/hisilicon/hisi_uncore_pmu.c b/drivers/perf/hisilicon/hisi_uncore_pmu.c
index 96183e31b96a..584de8f807cc 100644
--- a/drivers/perf/hisilicon/hisi_uncore_pmu.c
+++ b/drivers/perf/hisilicon/hisi_uncore_pmu.c
@@ -337,38 +337,44 @@ void hisi_uncore_pmu_disable(struct pmu *pmu)
 	hisi_pmu->ops->stop_counters(hisi_pmu);
 }
 
+
 /*
- * Read Super CPU cluster and CPU cluster ID from MPIDR_EL1.
- * If multi-threading is supported, On Huawei Kunpeng 920 SoC whose cpu
- * core is tsv110, CCL_ID is the low 3-bits in MPIDR[Aff2] and SCCL_ID
- * is the upper 5-bits of Aff2 field; while for other cpu types, SCCL_ID
- * is in MPIDR[Aff3] and CCL_ID is in MPIDR[Aff2], if not, SCCL_ID
- * is in MPIDR[Aff2] and CCL_ID is in MPIDR[Aff1].
+ * The Super CPU Cluster (SCCL) and CPU Cluster (CCL) IDs can be
+ * determined from the MPIDR_EL1, but the encoding varies by CPU:
+ *
+ * - For MT variants of TSV110:
+ *   SCCL is Aff2[7:3], CCL is Aff2[2:0]
+ *
+ * - For other MT parts:
+ *   SCCL is Aff3[7:0], CCL is Aff2[7:0]
+ *
+ * - For non-MT parts:
+ *   SCCL is Aff2[7:0], CCL is Aff1[7:0]
  */
-static void hisi_read_sccl_and_ccl_id(int *sccl_id, int *ccl_id)
+static void hisi_read_sccl_and_ccl_id(int *scclp, int *cclp)
 {
 	u64 mpidr = read_cpuid_mpidr();
-
-	if (mpidr & MPIDR_MT_BITMASK) {
-		if (read_cpuid_part_number() == HISI_CPU_PART_TSV110) {
-			int aff2 = MPIDR_AFFINITY_LEVEL(mpidr, 2);
-
-			if (sccl_id)
-				*sccl_id = aff2 >> 3;
-			if (ccl_id)
-				*ccl_id = aff2 & 0x7;
-		} else {
-			if (sccl_id)
-				*sccl_id = MPIDR_AFFINITY_LEVEL(mpidr, 3);
-			if (ccl_id)
-				*ccl_id = MPIDR_AFFINITY_LEVEL(mpidr, 2);
-		}
+	int aff3 = MPIDR_AFFINITY_LEVEL(mpidr, 3);
+	int aff2 = MPIDR_AFFINITY_LEVEL(mpidr, 2);
+	int aff1 = MPIDR_AFFINITY_LEVEL(mpidr, 1);
+	bool mt = mpidr & MPIDR_MT_BITMASK;
+	int sccl, ccl;
+
+	if (mt && read_cpuid_part_number() == HISI_CPU_PART_TSV110) {
+		sccl = aff2 >> 3;
+		ccl = aff2 & 0x7;
+	} else if (mt) {
+		sccl = aff3;
+		ccl = aff2;
 	} else {
-		if (sccl_id)
-			*sccl_id = MPIDR_AFFINITY_LEVEL(mpidr, 2);
-		if (ccl_id)
-			*ccl_id = MPIDR_AFFINITY_LEVEL(mpidr, 1);
+		sccl = aff2;
+		ccl = aff1;
 	}
+
+	if (scclp)
+		*scclp = sccl;
+	if (cclp)
+		*cclp = ccl;
 }
 
 /*
-- 
2.7.4


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^ permalink raw reply related	[flat|nested] 3+ messages in thread
* Re: [PATCH v2] drivers/perf: hisi: Simplify hisi_read_sccl_and_ccl_id and its comment
  2019-11-14  0:57 [PATCH v2] drivers/perf: hisi: Simplify hisi_read_sccl_and_ccl_id and its comment Shaokun Zhang
@ 2019-11-14  9:50 ` John Garry
  2019-11-14 13:37 ` Mark Rutland
  1 sibling, 0 replies; 3+ messages in thread
From: John Garry @ 2019-11-14  9:50 UTC (permalink / raw)
  To: Shaokun Zhang, linux-arm-kernel; +Cc: Mark Rutland, Will Deacon

On 14/11/2019 00:57, Shaokun Zhang wrote:
> hisi_read_sccl_and_ccl_id is not readable and its comment is a little
> confused, so simplify the function and its comment as Mark's suggestion.
> 
> Cc: John Garry<john.garry@huawei.com>
> Cc: Mark Rutland<mark.rutland@arm.com>
> Cc: Will Deacon<will@kernel.org>
> Suggested-by: Mark Rutland<mark.rutland@arm.com>
> Signed-off-by: Shaokun Zhang<zhangshaokun@hisilicon.com>

Reviewed-by: John Garry <john.garry@huawei.com>

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

^ permalink raw reply	[flat|nested] 3+ messages in thread
* Re: [PATCH v2] drivers/perf: hisi: Simplify hisi_read_sccl_and_ccl_id and its comment
  2019-11-14  0:57 [PATCH v2] drivers/perf: hisi: Simplify hisi_read_sccl_and_ccl_id and its comment Shaokun Zhang
  2019-11-14  9:50 ` John Garry
@ 2019-11-14 13:37 ` Mark Rutland
  1 sibling, 0 replies; 3+ messages in thread
From: Mark Rutland @ 2019-11-14 13:37 UTC (permalink / raw)
  To: Shaokun Zhang; +Cc: John Garry, Will Deacon, linux-arm-kernel

On Thu, Nov 14, 2019 at 08:57:03AM +0800, Shaokun Zhang wrote:
> hisi_read_sccl_and_ccl_id is not readable and its comment is a little
> confused, so simplify the function and its comment as Mark's suggestion.
> 
> Cc: John Garry <john.garry@huawei.com>
> Cc: Mark Rutland <mark.rutland@arm.com>
> Cc: Will Deacon <will@kernel.org>
> Suggested-by: Mark Rutland <mark.rutland@arm.com>
> Signed-off-by: Shaokun Zhang <zhangshaokun@hisilicon.com>

Acked-by: Mark Rutland <mark.rutland@arm.com>

I assume that Will can pick this up.

Mark.

> ---
> ChangeLog from V2:
>     Address John's comment: remove the confusing 'Kunpeng 920' comment who
> has two types.
> 
>  drivers/perf/hisilicon/hisi_uncore_pmu.c | 58 ++++++++++++++++++--------------
>  1 file changed, 32 insertions(+), 26 deletions(-)
> 
> diff --git a/drivers/perf/hisilicon/hisi_uncore_pmu.c b/drivers/perf/hisilicon/hisi_uncore_pmu.c
> index 96183e31b96a..584de8f807cc 100644
> --- a/drivers/perf/hisilicon/hisi_uncore_pmu.c
> +++ b/drivers/perf/hisilicon/hisi_uncore_pmu.c
> @@ -337,38 +337,44 @@ void hisi_uncore_pmu_disable(struct pmu *pmu)
>  	hisi_pmu->ops->stop_counters(hisi_pmu);
>  }
>  
> +
>  /*
> - * Read Super CPU cluster and CPU cluster ID from MPIDR_EL1.
> - * If multi-threading is supported, On Huawei Kunpeng 920 SoC whose cpu
> - * core is tsv110, CCL_ID is the low 3-bits in MPIDR[Aff2] and SCCL_ID
> - * is the upper 5-bits of Aff2 field; while for other cpu types, SCCL_ID
> - * is in MPIDR[Aff3] and CCL_ID is in MPIDR[Aff2], if not, SCCL_ID
> - * is in MPIDR[Aff2] and CCL_ID is in MPIDR[Aff1].
> + * The Super CPU Cluster (SCCL) and CPU Cluster (CCL) IDs can be
> + * determined from the MPIDR_EL1, but the encoding varies by CPU:
> + *
> + * - For MT variants of TSV110:
> + *   SCCL is Aff2[7:3], CCL is Aff2[2:0]
> + *
> + * - For other MT parts:
> + *   SCCL is Aff3[7:0], CCL is Aff2[7:0]
> + *
> + * - For non-MT parts:
> + *   SCCL is Aff2[7:0], CCL is Aff1[7:0]
>   */
> -static void hisi_read_sccl_and_ccl_id(int *sccl_id, int *ccl_id)
> +static void hisi_read_sccl_and_ccl_id(int *scclp, int *cclp)
>  {
>  	u64 mpidr = read_cpuid_mpidr();
> -
> -	if (mpidr & MPIDR_MT_BITMASK) {
> -		if (read_cpuid_part_number() == HISI_CPU_PART_TSV110) {
> -			int aff2 = MPIDR_AFFINITY_LEVEL(mpidr, 2);
> -
> -			if (sccl_id)
> -				*sccl_id = aff2 >> 3;
> -			if (ccl_id)
> -				*ccl_id = aff2 & 0x7;
> -		} else {
> -			if (sccl_id)
> -				*sccl_id = MPIDR_AFFINITY_LEVEL(mpidr, 3);
> -			if (ccl_id)
> -				*ccl_id = MPIDR_AFFINITY_LEVEL(mpidr, 2);
> -		}
> +	int aff3 = MPIDR_AFFINITY_LEVEL(mpidr, 3);
> +	int aff2 = MPIDR_AFFINITY_LEVEL(mpidr, 2);
> +	int aff1 = MPIDR_AFFINITY_LEVEL(mpidr, 1);
> +	bool mt = mpidr & MPIDR_MT_BITMASK;
> +	int sccl, ccl;
> +
> +	if (mt && read_cpuid_part_number() == HISI_CPU_PART_TSV110) {
> +		sccl = aff2 >> 3;
> +		ccl = aff2 & 0x7;
> +	} else if (mt) {
> +		sccl = aff3;
> +		ccl = aff2;
>  	} else {
> -		if (sccl_id)
> -			*sccl_id = MPIDR_AFFINITY_LEVEL(mpidr, 2);
> -		if (ccl_id)
> -			*ccl_id = MPIDR_AFFINITY_LEVEL(mpidr, 1);
> +		sccl = aff2;
> +		ccl = aff1;
>  	}
> +
> +	if (scclp)
> +		*scclp = sccl;
> +	if (cclp)
> +		*cclp = ccl;
>  }
>  
>  /*
> -- 
> 2.7.4
> 

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2019-11-14  0:57 [PATCH v2] drivers/perf: hisi: Simplify hisi_read_sccl_and_ccl_id and its comment Shaokun Zhang
2019-11-14  9:50 ` John Garry
2019-11-14 13:37 ` Mark Rutland

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