diff mbox series

[v2,04/10] interconnect: qcom: icc-rpm: Check for node-specific rate coefficients

Message ID 20230726-topic-icc_coeff-v2-4-8c91c6c76076@linaro.org
State New
Headers
Series Fix up icc clock rate calculation on some platforms |

Commit Message

Konrad Dybcio July 31, 2023, 10:52 a.m. UTC 
  Some nodes may have different coefficients than the general values for
bus they're attached to. Check for that and use them if present.

Signed-off-by: Konrad Dybcio <konrad.dybcio@linaro.org>
---
 drivers/interconnect/qcom/icc-rpm.c | 10 +++++++---
 drivers/interconnect/qcom/icc-rpm.h |  6 ++++++
 2 files changed, 13 insertions(+), 3 deletions(-)

Comments

Stephan Gerhold Aug. 1, 2023, 11:01 a.m. UTC | #1 
On Mon, Jul 31, 2023 at 12:52:20PM +0200, Konrad Dybcio wrote:
> Some nodes may have different coefficients than the general values for
> bus they're attached to. Check for that and use them if present.
> 
> Signed-off-by: Konrad Dybcio <konrad.dybcio@linaro.org>
> ---
>  drivers/interconnect/qcom/icc-rpm.c | 10 +++++++---
>  drivers/interconnect/qcom/icc-rpm.h |  6 ++++++
>  2 files changed, 13 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/interconnect/qcom/icc-rpm.c b/drivers/interconnect/qcom/icc-rpm.c
> index f0e575c95b49..91eb428385f6 100644
> --- a/drivers/interconnect/qcom/icc-rpm.c
> +++ b/drivers/interconnect/qcom/icc-rpm.c
> @@ -300,11 +300,15 @@ static u64 qcom_icc_calc_rate(struct qcom_icc_provider *qp, struct qcom_icc_node
>  	else
>  		agg_avg_rate = qn->sum_avg[ctx];
>  
> -	/* Check if the node has a specific coefficient first*/
> -	if (qp->ab_coeff)
> +	/* Check if the node has a specific coefficient first */
> +	if (qn->ab_coeff)
> +		agg_avg_rate = mult_frac(qn->ab_coeff, agg_avg_rate, 100);
> +	else if (qp->ab_coeff)
>  		agg_avg_rate = mult_frac(qp->ab_coeff, agg_avg_rate, 100);
>  
> -	if (qp->ib_coeff)
> +	if (qn->ab_coeff)
> +		agg_peak_rate = mult_frac(100, qn->max_peak[ctx], qn->ib_coeff);
> +	else if (qp->ib_coeff)
>  		agg_peak_rate = mult_frac(100, qn->max_peak[ctx], qp->ib_coeff);
>  	else
>  		agg_peak_rate = qn->max_peak[ctx];

Code/data size and likely performance would be slightly better if you
only add ab_coeff/ib_coeff to the node and not the provider. This is
slightly inconvenient because you need to duplicate the same value on
a lot of nodes, but the per-node memory is reserved anyway. You might
as well use I would say.

> diff --git a/drivers/interconnect/qcom/icc-rpm.h b/drivers/interconnect/qcom/icc-rpm.h
> index 835b83cfb548..1a26a7b82166 100644
> --- a/drivers/interconnect/qcom/icc-rpm.h
> +++ b/drivers/interconnect/qcom/icc-rpm.h
> @@ -103,6 +103,9 @@ struct qcom_icc_qos {
>   * @mas_rpm_id:	RPM id for devices that are bus masters
>   * @slv_rpm_id:	RPM id for devices that are bus slaves
>   * @qos: NoC QoS setting parameters
> + * @ab_coeff: a percentage-based coefficient for compensating the AB calculations
> + * @ib_coeff: an inverse-percentage-based coefficient for compensating the IB calculations
> + * @bus_clk_rate: a pointer to an array containing bus clock rates in Hz
>   */
>  struct qcom_icc_node {
>  	unsigned char *name;
> @@ -117,6 +120,9 @@ struct qcom_icc_node {
>  	int mas_rpm_id;
>  	int slv_rpm_id;
>  	struct qcom_icc_qos qos;
> +	u16 ab_coeff;
> +	u16 ib_coeff;
> +	u32 *bus_clk_rate;

bus_clk_rate should be in previous patch :)

Thanks,
Stephan
diff mbox series

Patch

diff --git a/drivers/interconnect/qcom/icc-rpm.c b/drivers/interconnect/qcom/icc-rpm.c
index f0e575c95b49..91eb428385f6 100644
--- a/drivers/interconnect/qcom/icc-rpm.c
+++ b/drivers/interconnect/qcom/icc-rpm.c
@@ -300,11 +300,15 @@  static u64 qcom_icc_calc_rate(struct qcom_icc_provider *qp, struct qcom_icc_node
 	else
 		agg_avg_rate = qn->sum_avg[ctx];
 
-	/* Check if the node has a specific coefficient first*/
-	if (qp->ab_coeff)
+	/* Check if the node has a specific coefficient first */
+	if (qn->ab_coeff)
+		agg_avg_rate = mult_frac(qn->ab_coeff, agg_avg_rate, 100);
+	else if (qp->ab_coeff)
 		agg_avg_rate = mult_frac(qp->ab_coeff, agg_avg_rate, 100);
 
-	if (qp->ib_coeff)
+	if (qn->ab_coeff)
+		agg_peak_rate = mult_frac(100, qn->max_peak[ctx], qn->ib_coeff);
+	else if (qp->ib_coeff)
 		agg_peak_rate = mult_frac(100, qn->max_peak[ctx], qp->ib_coeff);
 	else
 		agg_peak_rate = qn->max_peak[ctx];
diff --git a/drivers/interconnect/qcom/icc-rpm.h b/drivers/interconnect/qcom/icc-rpm.h
index 835b83cfb548..1a26a7b82166 100644
--- a/drivers/interconnect/qcom/icc-rpm.h
+++ b/drivers/interconnect/qcom/icc-rpm.h
@@ -103,6 +103,9 @@  struct qcom_icc_qos {
  * @mas_rpm_id:	RPM id for devices that are bus masters
  * @slv_rpm_id:	RPM id for devices that are bus slaves
  * @qos: NoC QoS setting parameters
+ * @ab_coeff: a percentage-based coefficient for compensating the AB calculations
+ * @ib_coeff: an inverse-percentage-based coefficient for compensating the IB calculations
+ * @bus_clk_rate: a pointer to an array containing bus clock rates in Hz
  */
 struct qcom_icc_node {
 	unsigned char *name;
@@ -117,6 +120,9 @@  struct qcom_icc_node {
 	int mas_rpm_id;
 	int slv_rpm_id;
 	struct qcom_icc_qos qos;
+	u16 ab_coeff;
+	u16 ib_coeff;
+	u32 *bus_clk_rate;
 };
 
 struct qcom_icc_desc {