[PATCH] interconnect: qcom: simplify allocation

[PATCH] interconnect: qcom: simplify allocation

[Rosen Penev]

Use a flexible array member to reduce allocation by 1.

Add __counted_by for extra runtime analysis. Move counting variable
assignment after allocation before any array access,

Signed-off-by: Rosen Penev <rosenp@gmail.com>
---
 drivers/interconnect/qcom/icc-rpm.c | 7 ++-----
 drivers/interconnect/qcom/icc-rpm.h | 2 +-
 2 files changed, 3 insertions(+), 6 deletions(-)

diff --git a/drivers/interconnect/qcom/icc-rpm.c b/drivers/interconnect/qcom/icc-rpm.c
index 23a1d116e79a..ca4c8a944755 100644
--- a/drivers/interconnect/qcom/icc-rpm.c
+++ b/drivers/interconnect/qcom/icc-rpm.c
@@ -479,13 +479,11 @@ int qnoc_probe(struct platform_device *pdev)
 		cd_num = 0;
 	}

-	qp = devm_kzalloc(dev, sizeof(*qp), GFP_KERNEL);
+	qp = devm_kzalloc(dev, struct_size(qp, intf_clks, cd_num), GFP_KERNEL);
 	if (!qp)
 		return -ENOMEM;

-	qp->intf_clks = devm_kcalloc(dev, cd_num, sizeof(*qp->intf_clks), GFP_KERNEL);
-	if (!qp->intf_clks)
-		return -ENOMEM;
+	qp->num_intf_clks = cd_num;

 	if (desc->bus_clk_desc) {
 		qp->bus_clk_desc = devm_kzalloc(dev, sizeof(*qp->bus_clk_desc),
@@ -507,7 +505,6 @@ int qnoc_probe(struct platform_device *pdev)
 		return -ENOMEM;
 	data->num_nodes = num_nodes;

-	qp->num_intf_clks = cd_num;
 	for (i = 0; i < cd_num; i++)
 		qp->intf_clks[i].id = cds[i];

diff --git a/drivers/interconnect/qcom/icc-rpm.h b/drivers/interconnect/qcom/icc-rpm.h
index 7d1cb2efa9ee..b08821c2ef74 100644
--- a/drivers/interconnect/qcom/icc-rpm.h
+++ b/drivers/interconnect/qcom/icc-rpm.h
@@ -64,9 +64,9 @@ struct qcom_icc_provider {
 	u32 bus_clk_rate[QCOM_SMD_RPM_STATE_NUM];
 	const struct rpm_clk_resource *bus_clk_desc;
 	struct clk *bus_clk;
-	struct clk_bulk_data *intf_clks;
 	bool keep_alive;
 	bool ignore_enxio;
+	struct clk_bulk_data intf_clks[] __counted_by(num_intf_clks);
 };

 /**
--
2.54.0

Re: [PATCH] interconnect: qcom: simplify allocation

[Dmitry Baryshkov]

On Sun, Jun 07, 2026 at 10:04:29PM -0700, Rosen Penev wrote:
> Use a flexible array member to reduce allocation by 1.
> 
> Add __counted_by for extra runtime analysis. Move counting variable
> assignment after allocation before any array access,
> 
> Signed-off-by: Rosen Penev <rosenp@gmail.com>
> ---
>  drivers/interconnect/qcom/icc-rpm.c | 7 ++-----
>  drivers/interconnect/qcom/icc-rpm.h | 2 +-
>  2 files changed, 3 insertions(+), 6 deletions(-)
> 

Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>


-- 
With best wishes
Dmitry

Re: [PATCH] interconnect: qcom: simplify allocation

[Konrad Dybcio]

On 6/8/26 7:04 AM, Rosen Penev wrote:
> Use a flexible array member to reduce allocation by 1.
> 
> Add __counted_by for extra runtime analysis. Move counting variable
> assignment after allocation before any array access,
> 
> Signed-off-by: Rosen Penev <rosenp@gmail.com>
> ---

[...]

> diff --git a/drivers/interconnect/qcom/icc-rpm.h b/drivers/interconnect/qcom/icc-rpm.h
> index 7d1cb2efa9ee..b08821c2ef74 100644
> --- a/drivers/interconnect/qcom/icc-rpm.h
> +++ b/drivers/interconnect/qcom/icc-rpm.h
> @@ -64,9 +64,9 @@ struct qcom_icc_provider {
>  	u32 bus_clk_rate[QCOM_SMD_RPM_STATE_NUM];
>  	const struct rpm_clk_resource *bus_clk_desc;
>  	struct clk *bus_clk;
> -	struct clk_bulk_data *intf_clks;
>  	bool keep_alive;
>  	bool ignore_enxio;
> +	struct clk_bulk_data intf_clks[] __counted_by(num_intf_clks);

nit: it's easier to visually track if these are kept together. I think
you may also need to update the kerneldoc as the order changes

Konrad