[PATCH] phy: mediatek: xsphy: reduce main allocation

[PATCH] phy: mediatek: xsphy: reduce main allocation

[Rosen Penev]

Instead of kzalloc and kcalloc, we can use a flex array to reduce to a
single allocation.

Also added __counted_by() for extra possible analysis.

Signed-off-by: Rosen Penev <rosenp@gmail.com>
---
 drivers/phy/mediatek/phy-mtk-xsphy.c | 15 ++++++---------
 1 file changed, 6 insertions(+), 9 deletions(-)

diff --git a/drivers/phy/mediatek/phy-mtk-xsphy.c b/drivers/phy/mediatek/phy-mtk-xsphy.c
index c0ddb9273cc3..cc1d66954212 100644
--- a/drivers/phy/mediatek/phy-mtk-xsphy.c
+++ b/drivers/phy/mediatek/phy-mtk-xsphy.c
@@ -112,10 +112,10 @@ struct xsphy_instance {
 struct mtk_xsphy {
 	struct device *dev;
 	void __iomem *glb_base;	/* only shared u3 sif */
-	struct xsphy_instance **phys;
-	int nphys;
 	int src_ref_clk; /* MHZ, reference clock for slew rate calibrate */
 	int src_coef;    /* coefficient for slew rate calibrate */
+	int nphys;
+	struct xsphy_instance *phys[] __counted_by(nphys);
 };
 
 static void u2_phy_slew_rate_calibrate(struct mtk_xsphy *xsphy,
@@ -515,18 +515,15 @@ static int mtk_xsphy_probe(struct platform_device *pdev)
 	struct resource *glb_res;
 	struct mtk_xsphy *xsphy;
 	struct resource res;
+	size_t nphys;
 	int port;
 
-	xsphy = devm_kzalloc(dev, sizeof(*xsphy), GFP_KERNEL);
+	nphys = of_get_child_count(np);
+	xsphy = devm_kzalloc(dev, struct_size(xsphy, phys, nphys), GFP_KERNEL);
 	if (!xsphy)
 		return -ENOMEM;
 
-	xsphy->nphys = of_get_child_count(np);
-	xsphy->phys = devm_kcalloc(dev, xsphy->nphys,
-				       sizeof(*xsphy->phys), GFP_KERNEL);
-	if (!xsphy->phys)
-		return -ENOMEM;
-
+	xsphy->nphys = nphys;
 	xsphy->dev = dev;
 	platform_set_drvdata(pdev, xsphy);
 
-- 
2.53.0


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Re: [PATCH] phy: mediatek: xsphy: reduce main allocation

[Gustavo A. R. Silva]

On 3/4/26 13:34, Rosen Penev wrote:
> Instead of kzalloc and kcalloc, we can use a flex array to reduce to a
> single allocation.
> 
> Also added __counted_by() for extra possible analysis.
> 
> Signed-off-by: Rosen Penev <rosenp@gmail.com>

Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org>

Thanks
-Gustavo

> ---
>   drivers/phy/mediatek/phy-mtk-xsphy.c | 15 ++++++---------
>   1 file changed, 6 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/phy/mediatek/phy-mtk-xsphy.c b/drivers/phy/mediatek/phy-mtk-xsphy.c
> index c0ddb9273cc3..cc1d66954212 100644
> --- a/drivers/phy/mediatek/phy-mtk-xsphy.c
> +++ b/drivers/phy/mediatek/phy-mtk-xsphy.c
> @@ -112,10 +112,10 @@ struct xsphy_instance {
>   struct mtk_xsphy {
>   	struct device *dev;
>   	void __iomem *glb_base;	/* only shared u3 sif */
> -	struct xsphy_instance **phys;
> -	int nphys;
>   	int src_ref_clk; /* MHZ, reference clock for slew rate calibrate */
>   	int src_coef;    /* coefficient for slew rate calibrate */
> +	int nphys;
> +	struct xsphy_instance *phys[] __counted_by(nphys);
>   };
>   
>   static void u2_phy_slew_rate_calibrate(struct mtk_xsphy *xsphy,
> @@ -515,18 +515,15 @@ static int mtk_xsphy_probe(struct platform_device *pdev)
>   	struct resource *glb_res;
>   	struct mtk_xsphy *xsphy;
>   	struct resource res;
> +	size_t nphys;
>   	int port;
>   
> -	xsphy = devm_kzalloc(dev, sizeof(*xsphy), GFP_KERNEL);
> +	nphys = of_get_child_count(np);
> +	xsphy = devm_kzalloc(dev, struct_size(xsphy, phys, nphys), GFP_KERNEL);
>   	if (!xsphy)
>   		return -ENOMEM;
>   
> -	xsphy->nphys = of_get_child_count(np);
> -	xsphy->phys = devm_kcalloc(dev, xsphy->nphys,
> -				       sizeof(*xsphy->phys), GFP_KERNEL);
> -	if (!xsphy->phys)
> -		return -ENOMEM;
> -
> +	xsphy->nphys = nphys;
>   	xsphy->dev = dev;
>   	platform_set_drvdata(pdev, xsphy);
>   


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