Subject: Re: [PATCH net-next 13/15] net: ethernet: mtk_wed: introduce hw_rro support for MT7988

From: Simon Horman <[email-masked]>
Date: Sun, 17 Sep 2023 10:47:28 +0200

On Thu, Sep 14, 2023 at 04:38:18PM +0200, Lorenzo Bianconi wrote:
> From: Sujuan Chen <[email-masked]>
> 
> MT7988 SoC support 802.11 receive reordering offload in hw while
> MT7986 SoC implements it through the firmware running on the mcu.
> 
> Co-developed-by: Lorenzo Bianconi <[email-masked]>
> Signed-off-by: Lorenzo Bianconi <[email-masked]>
> Signed-off-by: Sujuan Chen <[email-masked]>

...

Hi Lorenzo,

some minor feedback from my side.

> @@ -565,6 +565,73 @@ mtk_wed_free_tx_buffer(struct mtk_wed_device *dev)
>  	kfree(page_list);
>  }
>  
> +static int
> +mtk_wed_hwrro_buffer_alloc(struct mtk_wed_device *dev)
> +{
> +	int n_pages = MTK_WED_RX_PG_BM_CNT / MTK_WED_RX_BUF_PER_PAGE;
> +	struct mtk_wed_buf *page_list;
> +	struct mtk_wed_bm_desc *desc;
> +	dma_addr_t desc_phys;
> +	int i, page_idx = 0;
> +
> +	if (!dev->wlan.hw_rro)
> +		return 0;
> +
> +	page_list = kcalloc(n_pages, sizeof(*page_list), GFP_KERNEL);
> +	if (!page_list)
> +		return -ENOMEM;
> +
> +	dev->hw_rro.size = dev->wlan.rx_nbuf & ~(MTK_WED_BUF_PER_PAGE - 1);
> +	dev->hw_rro.pages = page_list;
> +	desc = dma_alloc_coherent(dev->hw->dev,
> +				  dev->wlan.rx_nbuf * sizeof(*desc),
> +				  &desc_phys, GFP_KERNEL);
> +	if (!desc)
> +		return -ENOMEM;
> +
> +	dev->hw_rro.desc = desc;
> +	dev->hw_rro.desc_phys = desc_phys;
> +
> +	for (i = 0; i < MTK_WED_RX_PG_BM_CNT; i += MTK_WED_RX_BUF_PER_PAGE) {
> +		dma_addr_t page_phys, buf_phys;
> +		struct page *page;
> +		void *buf;
> +		int s;
> +
> +		page = __dev_alloc_page(GFP_KERNEL);
> +		if (!page)
> +			return -ENOMEM;
> +
> +		page_phys = dma_map_page(dev->hw->dev, page, 0, PAGE_SIZE,
> +					 DMA_BIDIRECTIONAL);
> +		if (dma_mapping_error(dev->hw->dev, page_phys)) {
> +			__free_page(page);
> +			return -ENOMEM;
> +		}
> +
> +		page_list[page_idx].p = page;
> +		page_list[page_idx++].phy_addr = page_phys;
> +		dma_sync_single_for_cpu(dev->hw->dev, page_phys, PAGE_SIZE,
> +					DMA_BIDIRECTIONAL);
> +
> +		buf = page_to_virt(page);
> +		buf_phys = page_phys;
> +
> +		for (s = 0; s < MTK_WED_RX_BUF_PER_PAGE; s++) {
> +			desc->buf0 = cpu_to_le32(buf_phys);
> +			desc++;
> +
> +			buf += MTK_WED_PAGE_BUF_SIZE;

clang-16 W=1 warns that buf is set but otherwise unused in this function.

> +			buf_phys += MTK_WED_PAGE_BUF_SIZE;
> +		}
> +
> +		dma_sync_single_for_device(dev->hw->dev, page_phys, PAGE_SIZE,
> +					   DMA_BIDIRECTIONAL);
> +	}
> +
> +	return 0;
> +}
> +
>  static int
>  mtk_wed_rx_buffer_alloc(struct mtk_wed_device *dev)
>  {

...