Re: [PATCH net-next v2 2/3] net/stmmac/dwxgmac: Extend MTL/DMA support to 16 queues

[Larysa Zaremba]

On Mon, Jun 01, 2026 at 06:25:36PM +0200, Jakub Raczynski wrote:
> New datasheets for XGMAC (3.20a and 3.40a, depending on product) support up to
> 16 MTL/DMA queues. Before we increase max amount through macro,
> prepare dwxgmac functions to handle that.

Reviewed-by: Larysa Zaremba <larysa.zaremba@xxxxxxxxx>

> 
> Co-developed-by: Chang-Sub Lee <cs0617.lee@xxxxxxxxxxx>
> Signed-off-by: Chang-Sub Lee <cs0617.lee@xxxxxxxxxxx>
> Signed-off-by: Jakub Raczynski <j.raczynski@xxxxxxxxxxx>
> ---
>  .../net/ethernet/stmicro/stmmac/dwxgmac2.h    |  2 ++
>  .../ethernet/stmicro/stmmac/dwxgmac2_core.c   | 23 +++++++++++++++++--
>  2 files changed, 23 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/net/ethernet/stmicro/stmmac/dwxgmac2.h b/drivers/net/ethernet/stmicro/stmmac/dwxgmac2.h
> index 51943705a2b0..bd333afe7e1b 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/dwxgmac2.h
> +++ b/drivers/net/ethernet/stmicro/stmmac/dwxgmac2.h
> @@ -257,6 +257,8 @@
>  #define XGMAC_MTL_INT_STATUS		0x00001020
>  #define XGMAC_MTL_RXQ_DMA_MAP0		0x00001030
>  #define XGMAC_MTL_RXQ_DMA_MAP1		0x00001034
> +#define XGMAC_MTL_RXQ_DMA_MAP2		0x00001038
> +#define XGMAC_MTL_RXQ_DMA_MAP3		0x0000103c
>  #define XGMAC_QxMDMACH(x)		GENMASK((x) * 8 + 7, (x) * 8)
>  #define XGMAC_QxMDMACH_SHIFT(x)		((x) * 8)
>  #define XGMAC_QDDMACH			BIT(7)
> diff --git a/drivers/net/ethernet/stmicro/stmmac/dwxgmac2_core.c b/drivers/net/ethernet/stmicro/stmmac/dwxgmac2_core.c
> index dbedf31bb2ab..4aba62680938 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/dwxgmac2_core.c
> +++ b/drivers/net/ethernet/stmicro/stmmac/dwxgmac2_core.c
> @@ -278,12 +278,31 @@ static void dwxgmac2_set_mtl_tx_queue_weight(struct stmmac_priv *priv,
>  static void dwxgmac2_map_mtl_to_dma(struct mac_device_info *hw, u32 queue,
>  				    u32 chan)
>  {
> +	struct net_device *ndev = hw->priv_data->dev;
>  	void __iomem *ioaddr = hw->pcsr;
>  	u32 value, reg;
>  
> -	reg = (queue < 4) ? XGMAC_MTL_RXQ_DMA_MAP0 : XGMAC_MTL_RXQ_DMA_MAP1;
> -	if (queue >= 4)
> +	switch (queue) {
> +	case 0 ... 3:
> +		reg = XGMAC_MTL_RXQ_DMA_MAP0;
> +		break;
> +	case 4 ... 7:
> +		reg = XGMAC_MTL_RXQ_DMA_MAP1;
>  		queue -= 4;
> +		break;
> +	case 8 ... 11:
> +		reg = XGMAC_MTL_RXQ_DMA_MAP2;
> +		queue -= 8;
> +		break;
> +	case 12 ... 15:
> +		reg = XGMAC_MTL_RXQ_DMA_MAP3;
> +		queue -= 12;
> +		break;
> +	default:
> +		netdev_err(ndev, "%s: Incorrect queue mapping %d\n",
> +			   __func__, queue);
> +		return;
> +	}
>  
>  	value = readl(ioaddr + reg);
>  	value &= ~XGMAC_QxMDMACH(queue);
> -- 
> 2.34.1
> 
>