Re: [PATCH 07/31] net: mediatek: stop using bitfileds for DMA descriptors

[Ramon Fried <rfried.dev@gmail.com>]

On Thu, Aug 4, 2022 at 6:35 AM Weijie Gao <weijie.gao@mediatek.com> wrote:
>
> This patch is a preparation for adding a new version of PDMA of which the
> DMA descriptor fields has changed. Using bitfields will result in a complex
> modification. Convert bitfields to u32 units can solve this problem easily.
>
> Signed-off-by: Weijie Gao <weijie.gao@mediatek.com>
> ---
>  drivers/net/mtk_eth.c | 144 ++++++++++++++----------------------------
>  drivers/net/mtk_eth.h |  32 ++++++++++
>  2 files changed, 80 insertions(+), 96 deletions(-)
>
> diff --git a/drivers/net/mtk_eth.c b/drivers/net/mtk_eth.c
> index 92d2ea4f2a..bfa049cf79 100644
> --- a/drivers/net/mtk_eth.c
> +++ b/drivers/net/mtk_eth.c
> @@ -65,77 +65,6 @@
>         (DP_DISCARD << MC_DP_S) | \
>         (DP_DISCARD << UN_DP_S))
>
> -struct pdma_rxd_info1 {
> -       u32 PDP0;
> -};
> -
> -struct pdma_rxd_info2 {
> -       u32 PLEN1 : 14;
> -       u32 LS1 : 1;
> -       u32 UN_USED : 1;
> -       u32 PLEN0 : 14;
> -       u32 LS0 : 1;
> -       u32 DDONE : 1;
> -};
> -
> -struct pdma_rxd_info3 {
> -       u32 PDP1;
> -};
> -
> -struct pdma_rxd_info4 {
> -       u32 FOE_ENTRY : 14;
> -       u32 CRSN : 5;
> -       u32 SP : 3;
> -       u32 L4F : 1;
> -       u32 L4VLD : 1;
> -       u32 TACK : 1;
> -       u32 IP4F : 1;
> -       u32 IP4 : 1;
> -       u32 IP6 : 1;
> -       u32 UN_USED : 4;
> -};
> -
> -struct pdma_rxdesc {
> -       struct pdma_rxd_info1 rxd_info1;
> -       struct pdma_rxd_info2 rxd_info2;
> -       struct pdma_rxd_info3 rxd_info3;
> -       struct pdma_rxd_info4 rxd_info4;
> -};
> -
> -struct pdma_txd_info1 {
> -       u32 SDP0;
> -};
> -
> -struct pdma_txd_info2 {
> -       u32 SDL1 : 14;
> -       u32 LS1 : 1;
> -       u32 BURST : 1;
> -       u32 SDL0 : 14;
> -       u32 LS0 : 1;
> -       u32 DDONE : 1;
> -};
> -
> -struct pdma_txd_info3 {
> -       u32 SDP1;
> -};
> -
> -struct pdma_txd_info4 {
> -       u32 VLAN_TAG : 16;
> -       u32 INS : 1;
> -       u32 RESV : 2;
> -       u32 UDF : 6;
> -       u32 FPORT : 3;
> -       u32 TSO : 1;
> -       u32 TUI_CO : 3;
> -};
> -
> -struct pdma_txdesc {
> -       struct pdma_txd_info1 txd_info1;
> -       struct pdma_txd_info2 txd_info2;
> -       struct pdma_txd_info3 txd_info3;
> -       struct pdma_txd_info4 txd_info4;
> -};
> -
>  enum mtk_switch {
>         SW_NONE,
>         SW_MT7530,
> @@ -145,13 +74,15 @@ enum mtk_switch {
>  struct mtk_soc_data {
>         u32 caps;
>         u32 ana_rgc3;
> +       u32 txd_size;
> +       u32 rxd_size;
>  };
>
>  struct mtk_eth_priv {
>         char pkt_pool[TOTAL_PKT_BUF_SIZE] __aligned(ARCH_DMA_MINALIGN);
>
> -       struct pdma_txdesc *tx_ring_noc;
> -       struct pdma_rxdesc *rx_ring_noc;
> +       void *tx_ring_noc;
> +       void *rx_ring_noc;
>
>         int rx_dma_owner_idx0;
>         int tx_cpu_owner_idx0;
> @@ -1196,14 +1127,16 @@ static void mtk_mac_init(struct mtk_eth_priv *priv)
>  static void mtk_eth_fifo_init(struct mtk_eth_priv *priv)
>  {
>         char *pkt_base = priv->pkt_pool;
> +       struct mtk_tx_dma *txd;
> +       struct mtk_rx_dma *rxd;
>         int i;
>
>         mtk_pdma_rmw(priv, PDMA_GLO_CFG_REG, 0xffff0000, 0);
>         udelay(500);
>
> -       memset(priv->tx_ring_noc, 0, NUM_TX_DESC * sizeof(struct pdma_txdesc));
> -       memset(priv->rx_ring_noc, 0, NUM_RX_DESC * sizeof(struct pdma_rxdesc));
> -       memset(priv->pkt_pool, 0, TOTAL_PKT_BUF_SIZE);
> +       memset(priv->tx_ring_noc, 0, NUM_TX_DESC * priv->soc->txd_size);
> +       memset(priv->rx_ring_noc, 0, NUM_RX_DESC * priv->soc->rxd_size);
> +       memset(priv->pkt_pool, 0xff, TOTAL_PKT_BUF_SIZE);
>
>         flush_dcache_range((ulong)pkt_base,
>                            (ulong)(pkt_base + TOTAL_PKT_BUF_SIZE));
> @@ -1212,17 +1145,21 @@ static void mtk_eth_fifo_init(struct mtk_eth_priv
>  *priv)
>         priv->tx_cpu_owner_idx0 = 0;
>
>         for (i = 0; i < NUM_TX_DESC; i++) {
> -               priv->tx_ring_noc[i].txd_info2.LS0 = 1;
> -               priv->tx_ring_noc[i].txd_info2.DDONE = 1;
> -               priv->tx_ring_noc[i].txd_info4.FPORT = priv->gmac_id + 1;
> +               txd = priv->tx_ring_noc + i * priv->soc->txd_size;
> +
> +               txd->txd1 = virt_to_phys(pkt_base);
> +               txd->txd2 = PDMA_TXD2_DDONE | PDMA_TXD2_LS0;
> +               txd->txd4 = PDMA_TXD4_FPORT_SET(priv->gmac_id + 1);
>
> -               priv->tx_ring_noc[i].txd_info1.SDP0 = virt_to_phys(pkt_base);
>                 pkt_base += PKTSIZE_ALIGN;
>         }
>
>         for (i = 0; i < NUM_RX_DESC; i++) {
> -               priv->rx_ring_noc[i].rxd_info2.PLEN0 = PKTSIZE_ALIGN;
> -               priv->rx_ring_noc[i].rxd_info1.PDP0 = virt_to_phys(pkt_base);
> +               rxd = priv->rx_ring_noc + i * priv->soc->rxd_size;
> +
> +               rxd->rxd1 = virt_to_phys(pkt_base);
> +               rxd->rxd2 = PDMA_RXD2_PLEN0_SET(PKTSIZE_ALIGN);
> +
>                 pkt_base += PKTSIZE_ALIGN;
>         }
>
> @@ -1309,20 +1246,22 @@ static int mtk_eth_send(struct udevice *dev, void
>  *packet, int length)
>  {
>         struct mtk_eth_priv *priv = dev_get_priv(dev);
>         u32 idx = priv->tx_cpu_owner_idx0;
> +       struct mtk_tx_dma *txd;
>         void *pkt_base;
>
> -       if (!priv->tx_ring_noc[idx].txd_info2.DDONE) {
> +       txd = priv->tx_ring_noc + idx * priv->soc->txd_size;
> +
> +       if (!(txd->txd2 & PDMA_TXD2_DDONE)) {
>                 debug("mtk-eth: TX DMA descriptor ring is full\n");
>                 return -EPERM;
>         }
>
> -       pkt_base = (void *)phys_to_virt(priv->tx_ring_noc[idx].txd_info1.SDP0);
> +       pkt_base = (void *)phys_to_virt(txd->txd1);
>         memcpy(pkt_base, packet, length);
>         flush_dcache_range((ulong)pkt_base, (ulong)pkt_base +
>                            roundup(length, ARCH_DMA_MINALIGN));
>
> -       priv->tx_ring_noc[idx].txd_info2.SDL0 = length;
> -       priv->tx_ring_noc[idx].txd_info2.DDONE = 0;
> +       txd->txd2 = PDMA_TXD2_LS0 | PDMA_TXD2_SDL0_SET(length);
>
>         priv->tx_cpu_owner_idx0 = (priv->tx_cpu_owner_idx0 + 1) % NUM_TX_DESC;
>         mtk_pdma_write(priv, TX_CTX_IDX_REG(0), priv->tx_cpu_owner_idx0);
> @@ -1334,16 +1273,20 @@ static int mtk_eth_recv(struct udevice *dev, int
>  flags, uchar **packetp)
>  {
>         struct mtk_eth_priv *priv = dev_get_priv(dev);
>         u32 idx = priv->rx_dma_owner_idx0;
> +       struct mtk_rx_dma *rxd;
>         uchar *pkt_base;
>         u32 length;
>
> -       if (!priv->rx_ring_noc[idx].rxd_info2.DDONE) {
> +       rxd = priv->rx_ring_noc + idx * priv->soc->rxd_size;
> +
> +       if (!(rxd->rxd2 & PDMA_RXD2_DDONE)) {
>                 debug("mtk-eth: RX DMA descriptor ring is empty\n");
>                 return -EAGAIN;
>         }
>
> -       length = priv->rx_ring_noc[idx].rxd_info2.PLEN0;
> -       pkt_base = (void *)phys_to_virt(priv->rx_ring_noc[idx].rxd_info1.PDP0);
> +       length = PDMA_RXD2_PLEN0_GET(rxd->rxd2);
> +
> +       pkt_base = (void *)phys_to_virt(rxd->rxd1);
>         invalidate_dcache_range((ulong)pkt_base, (ulong)pkt_base +
>                                 roundup(length, ARCH_DMA_MINALIGN));
>
> @@ -1357,10 +1300,11 @@ static int mtk_eth_free_pkt(struct udevice *dev,
>  uchar *packet, int length)
>  {
>         struct mtk_eth_priv *priv = dev_get_priv(dev);
>         u32 idx = priv->rx_dma_owner_idx0;
> +       struct mtk_rx_dma *rxd;
> +
> +       rxd = priv->rx_ring_noc + idx * priv->soc->rxd_size;
>
> -       priv->rx_ring_noc[idx].rxd_info2.DDONE = 0;
> -       priv->rx_ring_noc[idx].rxd_info2.LS0 = 0;
> -       priv->rx_ring_noc[idx].rxd_info2.PLEN0 = PKTSIZE_ALIGN;
> +       rxd->rxd2 = PDMA_RXD2_PLEN0_SET(PKTSIZE_ALIGN);
>
>         mtk_pdma_write(priv, RX_CRX_IDX_REG(0), idx);
>         priv->rx_dma_owner_idx0 = (priv->rx_dma_owner_idx0 + 1) % NUM_RX_DESC;
> @@ -1387,11 +1331,11 @@ static int mtk_eth_probe(struct udevice *dev)
>                 return ret;
>
>         /* Prepare for tx/rx rings */
> -       priv->tx_ring_noc = (struct pdma_txdesc *)
> -               noncached_alloc(sizeof(struct pdma_txdesc) * NUM_TX_DESC,
> +       priv->tx_ring_noc = (void *)
> +               noncached_alloc(priv->soc->txd_size * NUM_TX_DESC,
>                                 ARCH_DMA_MINALIGN);
> -       priv->rx_ring_noc = (struct pdma_rxdesc *)
> -               noncached_alloc(sizeof(struct pdma_rxdesc) * NUM_RX_DESC,
> +       priv->rx_ring_noc = (void *)
> +               noncached_alloc(priv->soc->rxd_size * NUM_RX_DESC,
>                                 ARCH_DMA_MINALIGN);
>
>         /* Set MAC mode */
> @@ -1548,18 +1492,26 @@ static int mtk_eth_of_to_plat(struct udevice *dev)
>
>  static const struct mtk_soc_data mt7629_data = {
>         .ana_rgc3 = 0x128,
> +       .txd_size = sizeof(struct mtk_tx_dma),
> +       .rxd_size = sizeof(struct mtk_rx_dma),
>  };
>
>  static const struct mtk_soc_data mt7623_data = {
>         .caps = MT7623_CAPS,
> +       .txd_size = sizeof(struct mtk_tx_dma),
> +       .rxd_size = sizeof(struct mtk_rx_dma),
>  };
>
>  static const struct mtk_soc_data mt7622_data = {
>         .ana_rgc3 = 0x2028,
> +       .txd_size = sizeof(struct mtk_tx_dma),
> +       .rxd_size = sizeof(struct mtk_rx_dma),
>  };
>
>  static const struct mtk_soc_data mt7621_data = {
>         .caps = MT7621_CAPS,
> +       .txd_size = sizeof(struct mtk_tx_dma),
> +       .rxd_size = sizeof(struct mtk_rx_dma),
>  };
>
>  static const struct udevice_id mtk_eth_ids[] = {
> diff --git a/drivers/net/mtk_eth.h b/drivers/net/mtk_eth.h
> index 15c2030617..65bc9fcc04 100644
> --- a/drivers/net/mtk_eth.h
> +++ b/drivers/net/mtk_eth.h
> @@ -10,6 +10,7 @@
>  #define _MTK_ETH_H_
>
>  #include <linux/bitops.h>
> +#include <linux/bitfield.h>
>
>  enum mkt_eth_capabilities {
>         MTK_TRGMII_BIT,
> @@ -435,4 +436,35 @@ enum mkt_eth_capabilities {
>  #define PHY_POWER_SAVING_M             0x300
>  #define PHY_POWER_SAVING_TX            0x0
>
> +/* PDMA descriptors */
> +struct mtk_rx_dma {
> +       unsigned int rxd1;
> +       unsigned int rxd2;
> +       unsigned int rxd3;
> +       unsigned int rxd4;
> +} __packed __aligned(4);
> +
> +struct mtk_tx_dma {
> +       unsigned int txd1;
> +       unsigned int txd2;
> +       unsigned int txd3;
> +       unsigned int txd4;
> +} __packed __aligned(4);
> +
> +/* PDMA TXD fields */
> +#define PDMA_TXD2_DDONE                        BIT(31)
> +#define PDMA_TXD2_LS0                  BIT(30)
> +#define PDMA_TXD2_SDL0_M               GENMASK(29, 16)
> +#define PDMA_TXD2_SDL0_SET(_v) FIELD_PREP(PDMA_TXD2_SDL0_M, (_v))
> +
> +#define PDMA_TXD4_FPORT_M              GENMASK(27, 25)
> +#define PDMA_TXD4_FPORT_SET(_v)        FIELD_PREP(PDMA_TXD4_FPORT_M, (_v))
> +
> +/* PDMA RXD fields */
> +#define PDMA_RXD2_DDONE                        BIT(31)
> +#define PDMA_RXD2_LS0                  BIT(30)
> +#define PDMA_RXD2_PLEN0_M              GENMASK(29, 16)
> +#define PDMA_RXD2_PLEN0_GET(_v)        FIELD_GET(PDMA_RXD2_PLEN0_M, (_v))
> +#define PDMA_RXD2_PLEN0_SET(_v)        FIELD_PREP(PDMA_RXD2_PLEN0_M, (_v))
> +
>  #endif /* _MTK_ETH_H_ */
> --
> 2.17.1
>
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