Re: [PATCH net-next V2 2/3] net: stmmac: dwmac-loongson: Add new multi-chan IP core support

[Yanteng Si <si.yanteng@linux.dev>]

在 4/16/25 10:41 PM, Huacai Chen 写道:
> Add a new multi-chan IP core (0x12) support which is used in Loongson-
> 2K3000/Loongson-3B6000M. Compared with the 0x10 core, the new 0x12 core
> reduces channel numbers from 8 to 4, but checksum is supported for all
> channels.
>
> Reviewed-by: Andrew Lunn <andrew@lunn.ch>
> Tested-by: Henry Chen <chenx97@aosc.io>
> Tested-by: Biao Dong <dongbiao@loongson.cn>
> Signed-off-by: Baoqi Zhang <zhangbaoqi@loongson.cn>
> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
> ---
>   .../ethernet/stmicro/stmmac/dwmac-loongson.c  | 62 +++++++++++--------
>   1 file changed, 37 insertions(+), 25 deletions(-)
>
> diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-loongson.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-loongson.c
> index 2fb7a137b312..57917f26ab4d 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/dwmac-loongson.c
> +++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-loongson.c
> @@ -68,10 +68,11 @@
>   
>   #define PCI_DEVICE_ID_LOONGSON_GMAC	0x7a03
>   #define PCI_DEVICE_ID_LOONGSON_GNET	0x7a13
> -#define DWMAC_CORE_LS_MULTICHAN	0x10	/* Loongson custom ID */
> -#define CHANNEL_NUM			8
> +#define DWMAC_CORE_MULTICHAN_V1	0x10	/* Loongson custom ID 0x10 */
> +#define DWMAC_CORE_MULTICHAN_V2	0x12	/* Loongson custom ID 0x12 */
>   
>   struct loongson_data {
> +	u32 multichan;

In order to make the logic clearer, I suggest splitting this patch.：


2/4  Add multichan for loongson_data

3/4 Add new multi-chan IP core support


>   	u32 loongson_id;
>   	struct device *dev;
>   };
> @@ -119,18 +120,29 @@ static void loongson_default_data(struct pci_dev *pdev,
>   	plat->dma_cfg->pbl = 32;
>   	plat->dma_cfg->pblx8 = true;
>   
> -	if (ld->loongson_id == DWMAC_CORE_LS_MULTICHAN) {
> -		plat->rx_queues_to_use = CHANNEL_NUM;
> -		plat->tx_queues_to_use = CHANNEL_NUM;
> +	switch (ld->loongson_id) {
> +	case DWMAC_CORE_MULTICHAN_V1:

How about adding some comments? For example:

case DWMAC_CORE_MULTICHAN_V1:	/* 2K2000 */
case DWMAC_CORE_MULTICHAN_V2:	/* 2K3000 and 3B6000M */
...

> +		ld->multichan = 1;
> +		plat->rx_queues_to_use = 8;
> +		plat->tx_queues_to_use = 8;
>   
>   		/* Only channel 0 supports checksum,
>   		 * so turn off checksum to enable multiple channels.
>   		 */
> -		for (int i = 1; i < CHANNEL_NUM; i++)
> +		for (int i = 1; i < 8; i++)
>   			plat->tx_queues_cfg[i].coe_unsupported = 1;
> -	} else {
> +
> +		break;
> +	case DWMAC_CORE_MULTICHAN_V2:
> +		ld->multichan = 1;
> +		plat->rx_queues_to_use = 4;
> +		plat->tx_queues_to_use = 4;
> +		break;
> +	default:
> +		ld->multichan = 0;
>   		plat->tx_queues_to_use = 1;
>   		plat->rx_queues_to_use = 1;
> +		break;
>   	}
>   }
>   
> @@ -328,14 +340,14 @@ static struct mac_device_info *loongson_dwmac_setup(void *apriv)
>   		return NULL;
>   
>   	/* The Loongson GMAC and GNET devices are based on the DW GMAC
> -	 * v3.50a and v3.73a IP-cores. But the HW designers have changed the
> -	 * GMAC_VERSION.SNPSVER field to the custom 0x10 value on the
> -	 * network controllers with the multi-channels feature
> +	 * v3.50a and v3.73a IP-cores. But the HW designers have changed
> +	 * the GMAC_VERSION.SNPSVER field to the custom 0x10/0x12 value
> +	 * on the network controllers with the multi-channels feature
>   	 * available to emphasize the differences: multiple DMA-channels,
>   	 * AV feature and GMAC_INT_STATUS CSR flags layout. Get back the
>   	 * original value so the correct HW-interface would be selected.
>   	 */
> -	if (ld->loongson_id == DWMAC_CORE_LS_MULTICHAN) {
> +	if (ld->multichan) {
>   		priv->synopsys_id = DWMAC_CORE_3_70;
>   		*dma = dwmac1000_dma_ops;
>   		dma->init_chan = loongson_dwmac_dma_init_channel;
> @@ -356,13 +368,13 @@ static struct mac_device_info *loongson_dwmac_setup(void *apriv)
>   	if (mac->multicast_filter_bins)
>   		mac->mcast_bits_log2 = ilog2(mac->multicast_filter_bins);
>   
> -	/* Loongson GMAC doesn't support the flow control. LS2K2000
> -	 * GNET doesn't support the half-duplex link mode.
> +	/* Loongson GMAC doesn't support the flow control. Loongson GNET
> +	 * without multi-channel doesn't support the half-duplex link mode.
>   	 */
>   	if (pdev->device == PCI_DEVICE_ID_LOONGSON_GMAC) {
>   		mac->link.caps = MAC_10 | MAC_100 | MAC_1000;
>   	} else {
> -		if (ld->loongson_id == DWMAC_CORE_LS_MULTICHAN)
> +		if (ld->multichan)
>   			mac->link.caps = MAC_ASYM_PAUSE | MAC_SYM_PAUSE |
>   					 MAC_10 | MAC_100 | MAC_1000;
>   		else
> @@ -391,9 +403,11 @@ static int loongson_dwmac_msi_config(struct pci_dev *pdev,
>   				     struct plat_stmmacenet_data *plat,
>   				     struct stmmac_resources *res)
>   {
> -	int i, ret, vecs;
> +	int i, ch_num, ret, vecs;
>   
> -	vecs = roundup_pow_of_two(CHANNEL_NUM * 2 + 1);
> +	ch_num = min(plat->tx_queues_to_use, plat->rx_queues_to_use);

I'm curious. Will there still be hardware with RX not equal to TX in the 
future?


Thanks,

Yanteng