[PATCH net-next v2 4/4] net: ethernet: mtk_eth_soc: support 36-bit DMA addressing on MT7988
Daniel Golle
daniel at makrotopia.org
Mon Aug 21 16:32:58 PDT 2023
On Tue, Aug 22, 2023 at 12:30:34AM +0100, Daniel Golle wrote:
> Systems having 4 GiB of RAM and more require DMA addressing beyond the
> current 32-bit limit. Starting from MT7988 the hardware now supports
> 36-bit DMA addressing, let's use that new capability in the driver to
> avoid running into swiotlb on systems with 4 GiB of RAM or more.
>
> Signed-off-by: Daniel Golle <daniel at makrotopia.org>
> ---
> drivers/net/ethernet/mediatek/mtk_eth_soc.c | 34 ++++++++++++++++++---
> drivers/net/ethernet/mediatek/mtk_eth_soc.h | 22 +++++++++++--
> 2 files changed, 50 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.c b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
> index ec6a251a0f026..c40e69ac2eeaa 100644
> --- a/drivers/net/ethernet/mediatek/mtk_eth_soc.c
> +++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
> @@ -1136,7 +1136,7 @@ static int mtk_init_fq_dma(struct mtk_eth *eth)
> int i;
>
> if (MTK_HAS_CAPS(eth->soc->caps, MTK_SRAM))
> - eth->scratch_ring = eth->sram_base;
> + eth->scratch_ring = (void __force *)eth->sram_base;
Ooops that was supposed to go into the previous commit obviously.
I will submit v3 after some time with that fixed.
> else
> eth->scratch_ring = dma_alloc_coherent(eth->dma_dev,
> cnt * soc->txrx.txd_size,
> @@ -1328,6 +1328,10 @@ static void mtk_tx_set_dma_desc_v2(struct net_device *dev, void *txd,
> data = TX_DMA_PLEN0(info->size);
> if (info->last)
> data |= TX_DMA_LS0;
> +
> + if (MTK_HAS_CAPS(eth->soc->caps, MTK_36BIT_DMA))
> + data |= TX_DMA_PREP_ADDR64(info->addr);
> +
> WRITE_ONCE(desc->txd3, data);
>
> /* set forward port */
> @@ -1997,6 +2001,7 @@ static int mtk_poll_rx(struct napi_struct *napi, int budget,
> bool xdp_flush = false;
> int idx;
> struct sk_buff *skb;
> + u64 addr64 = 0;
> u8 *data, *new_data;
> struct mtk_rx_dma_v2 *rxd, trxd;
> int done = 0, bytes = 0;
> @@ -2112,7 +2117,10 @@ static int mtk_poll_rx(struct napi_struct *napi, int budget,
> goto release_desc;
> }
>
> - dma_unmap_single(eth->dma_dev, trxd.rxd1,
> + if (MTK_HAS_CAPS(eth->soc->caps, MTK_36BIT_DMA))
> + addr64 = RX_DMA_GET_ADDR64(trxd.rxd2);
> +
> + dma_unmap_single(eth->dma_dev, ((u64)trxd.rxd1 | addr64),
> ring->buf_size, DMA_FROM_DEVICE);
>
> skb = build_skb(data, ring->frag_size);
> @@ -2178,6 +2186,9 @@ static int mtk_poll_rx(struct napi_struct *napi, int budget,
> else
> rxd->rxd2 = RX_DMA_PREP_PLEN0(ring->buf_size);
>
> + if (MTK_HAS_CAPS(eth->soc->caps, MTK_36BIT_DMA))
> + rxd->rxd2 |= RX_DMA_PREP_ADDR64(dma_addr);
> +
> ring->calc_idx = idx;
> done++;
> }
> @@ -2450,7 +2461,7 @@ static int mtk_tx_alloc(struct mtk_eth *eth)
> goto no_tx_mem;
>
> if (MTK_HAS_CAPS(soc->caps, MTK_SRAM)) {
> - ring->dma = eth->sram_base + ring_size * sz;
> + ring->dma = (void __force *)eth->sram_base + ring_size * sz;
> ring->phys = eth->phy_scratch_ring + ring_size * (dma_addr_t)sz;
> } else {
> ring->dma = dma_alloc_coherent(eth->dma_dev, ring_size * sz,
> @@ -2670,6 +2681,9 @@ static int mtk_rx_alloc(struct mtk_eth *eth, int ring_no, int rx_flag)
> else
> rxd->rxd2 = RX_DMA_PREP_PLEN0(ring->buf_size);
>
> + if (MTK_HAS_CAPS(eth->soc->caps, MTK_36BIT_DMA))
> + rxd->rxd2 |= RX_DMA_PREP_ADDR64(dma_addr);
> +
> rxd->rxd3 = 0;
> rxd->rxd4 = 0;
> if (mtk_is_netsys_v2_or_greater(eth)) {
> @@ -2716,6 +2730,7 @@ static int mtk_rx_alloc(struct mtk_eth *eth, int ring_no, int rx_flag)
>
> static void mtk_rx_clean(struct mtk_eth *eth, struct mtk_rx_ring *ring, bool in_sram)
> {
> + u64 addr64 = 0;
> int i;
>
> if (ring->data && ring->dma) {
> @@ -2729,7 +2744,10 @@ static void mtk_rx_clean(struct mtk_eth *eth, struct mtk_rx_ring *ring, bool in_
> if (!rxd->rxd1)
> continue;
>
> - dma_unmap_single(eth->dma_dev, rxd->rxd1,
> + if (MTK_HAS_CAPS(eth->soc->caps, MTK_36BIT_DMA))
> + addr64 = RX_DMA_GET_ADDR64(rxd->rxd2);
> +
> + dma_unmap_single(eth->dma_dev, ((u64)rxd->rxd1 | addr64),
> ring->buf_size, DMA_FROM_DEVICE);
> mtk_rx_put_buff(ring, ring->data[i], false);
> }
> @@ -4734,6 +4752,14 @@ static int mtk_probe(struct platform_device *pdev)
> }
> }
>
> + if (MTK_HAS_CAPS(eth->soc->caps, MTK_36BIT_DMA)) {
> + err = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(36));
> + if (err) {
> + dev_err(&pdev->dev, "Wrong DMA config\n");
> + return -EINVAL;
> + }
> + }
> +
> spin_lock_init(ð->page_lock);
> spin_lock_init(ð->tx_irq_lock);
> spin_lock_init(ð->rx_irq_lock);
> diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.h b/drivers/net/ethernet/mediatek/mtk_eth_soc.h
> index 7c180aedcc0cd..186767bcf6837 100644
> --- a/drivers/net/ethernet/mediatek/mtk_eth_soc.h
> +++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.h
> @@ -331,6 +331,14 @@
> #define TX_DMA_PLEN1(x) ((x) & eth->soc->txrx.dma_max_len)
> #define TX_DMA_SWC BIT(14)
> #define TX_DMA_PQID GENMASK(3, 0)
> +#define TX_DMA_ADDR64_MASK GENMASK(3, 0)
> +#if IS_ENABLED(CONFIG_64BIT)
> +# define TX_DMA_GET_ADDR64(x) (((u64)FIELD_GET(TX_DMA_ADDR64_MASK, (x))) << 32)
> +# define TX_DMA_PREP_ADDR64(x) FIELD_PREP(TX_DMA_ADDR64_MASK, ((x) >> 32))
> +#else
> +# define TX_DMA_GET_ADDR64(x) (0)
> +# define TX_DMA_PREP_ADDR64(x) (0)
> +#endif
>
> /* PDMA on MT7628 */
> #define TX_DMA_DONE BIT(31)
> @@ -343,6 +351,14 @@
> #define RX_DMA_PREP_PLEN0(x) (((x) & eth->soc->txrx.dma_max_len) << eth->soc->txrx.dma_len_offset)
> #define RX_DMA_GET_PLEN0(x) (((x) >> eth->soc->txrx.dma_len_offset) & eth->soc->txrx.dma_max_len)
> #define RX_DMA_VTAG BIT(15)
> +#define RX_DMA_ADDR64_MASK GENMASK(3, 0)
> +#if IS_ENABLED(CONFIG_64BIT)
> +# define RX_DMA_GET_ADDR64(x) (((u64)FIELD_GET(RX_DMA_ADDR64_MASK, (x))) << 32)
> +# define RX_DMA_PREP_ADDR64(x) FIELD_PREP(RX_DMA_ADDR64_MASK, ((x) >> 32))
> +#else
> +# define RX_DMA_GET_ADDR64(x) (0)
> +# define RX_DMA_PREP_ADDR64(x) (0)
> +#endif
>
> /* QDMA descriptor rxd3 */
> #define RX_DMA_VID(x) ((x) & VLAN_VID_MASK)
> @@ -942,6 +958,7 @@ enum mkt_eth_capabilities {
> MTK_RSTCTRL_PPE2_BIT,
> MTK_U3_COPHY_V2_BIT,
> MTK_SRAM_BIT,
> + MTK_36BIT_DMA_BIT,
>
> /* MUX BITS*/
> MTK_ETH_MUX_GDM1_TO_GMAC1_ESW_BIT,
> @@ -978,6 +995,7 @@ enum mkt_eth_capabilities {
> #define MTK_RSTCTRL_PPE2 BIT_ULL(MTK_RSTCTRL_PPE2_BIT)
> #define MTK_U3_COPHY_V2 BIT_ULL(MTK_U3_COPHY_V2_BIT)
> #define MTK_SRAM BIT_ULL(MTK_SRAM_BIT)
> +#define MTK_36BIT_DMA BIT_ULL(MTK_36BIT_DMA_BIT)
>
> #define MTK_ETH_MUX_GDM1_TO_GMAC1_ESW \
> BIT_ULL(MTK_ETH_MUX_GDM1_TO_GMAC1_ESW_BIT)
> @@ -1059,8 +1077,8 @@ enum mkt_eth_capabilities {
> MTK_MUX_GMAC12_TO_GEPHY_SGMII | MTK_QDMA | \
> MTK_RSTCTRL_PPE1 | MTK_SRAM)
>
> -#define MT7988_CAPS (MTK_GDM1_ESW | MTK_QDMA | MTK_RSTCTRL_PPE1 | \
> - MTK_RSTCTRL_PPE2 | MTK_SRAM)
> +#define MT7988_CAPS (MTK_36BIT_DMA | MTK_GDM1_ESW | MTK_QDMA | \
> + MTK_RSTCTRL_PPE1 | MTK_RSTCTRL_PPE2 | MTK_SRAM)
>
> struct mtk_tx_dma_desc_info {
> dma_addr_t addr;
> --
> 2.41.0
>
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