On Tue, Apr 04, 2017 at 06:54:24PM +0100, Joao Pinto wrote: > This patch breaks several functions into RX and TX scopes, which > will be useful when adding multiple buffers mechanism. > > Signed-off-by: Joao Pinto <jpi...@synopsys.com> > --- > drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 350 > +++++++++++++++++----- > 1 file changed, 268 insertions(+), 82 deletions(-)
A couple of small nits below.
> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
[...]
> @@ -924,16 +941,16 @@ static int stmmac_set_bfsize(int mtu, int bufsize)
> }
>
> /**
> - * stmmac_clear_descriptors - clear descriptors
> + * stmmac_clear_rx_descriptors - clear RX descriptors
> * @priv: driver private structure
> - * Description: this function is called to clear the tx and rx descriptors
> + * Description: this function is called to clear the rx descriptors
You seem to be transitioning to "RX" and "TX" everywhere, maybe do the
same in this comment for consistency?
Also, on a general note: there's no need for "Description:" here. The
kerneldoc format mandates that you leave a blank line after the block
of parameter descriptions, and the paragraph that follows becomes the
description. I know that these are static functions and are therefore
not parsed by kerneldoc, but since you already use the syntax anyway,
you might as well get it right.
> * in case of both basic and extended descriptors are used.
> */
> -static void stmmac_clear_descriptors(struct stmmac_priv *priv)
> +static void stmmac_clear_rx_descriptors(struct stmmac_priv *priv)
> {
> int i;
This could be unsigned.
>
> - /* Clear the Rx/Tx descriptors */
> + /* Clear the RX descriptors */
> for (i = 0; i < DMA_RX_SIZE; i++)
> if (priv->extend_desc)
> priv->hw->desc->init_rx_desc(&priv->dma_erx[i].basic,
> @@ -943,6 +960,19 @@ static void stmmac_clear_descriptors(struct stmmac_priv
> *priv)
> priv->hw->desc->init_rx_desc(&priv->dma_rx[i],
> priv->use_riwt, priv->mode,
> (i == DMA_RX_SIZE - 1));
> +}
> +
> +/**
> + * stmmac_clear_tx_descriptors - clear tx descriptors
> + * @priv: driver private structure
> + * Description: this function is called to clear the tx descriptors
> + * in case of both basic and extended descriptors are used.
> + */
> +static void stmmac_clear_tx_descriptors(struct stmmac_priv *priv)
> +{
> + int i;
Same here. There are a couple of other such occurrences throughout the
file. This already exists in many places in the driver, so I don't think
this needs to be changed. Or at least it could be a follow-up patch.
> +
> + /* Clear the TX descriptors */
> for (i = 0; i < DMA_TX_SIZE; i++)
> if (priv->extend_desc)
> priv->hw->desc->init_tx_desc(&priv->dma_etx[i].basic,
> @@ -955,6 +985,21 @@ static void stmmac_clear_descriptors(struct stmmac_priv
> *priv)
> }
>
> /**
> + * stmmac_clear_descriptors - clear descriptors
> + * @priv: driver private structure
> + * Description: this function is called to clear the tx and rx descriptors
> + * in case of both basic and extended descriptors are used.
> + */
> +static void stmmac_clear_descriptors(struct stmmac_priv *priv)
> +{
> + /* Clear the RX descriptors */
> + stmmac_clear_rx_descriptors(priv);
> +
> + /* Clear the TX descriptors */
> + stmmac_clear_tx_descriptors(priv);
> +}
> +
> +/**
> * stmmac_init_rx_buffers - init the RX descriptor buffer.
> * @priv: driver private structure
> * @p: descriptor pointer
> @@ -996,6 +1041,11 @@ static int stmmac_init_rx_buffers(struct stmmac_priv
> *priv, struct dma_desc *p,
> return 0;
> }
>
> +/**
> + * stmmac_free_rx_buffers - free RX dma buffers
> + * @priv: private structure
> + * @i: buffer index.
If this operates on a single buffer, as specified by the buffer index,
maybe this should be named singular stmmac_free_rx_buffer()?
> + */
> static void stmmac_free_rx_buffers(struct stmmac_priv *priv, int i)
The index could be unsigned.
> {
> if (priv->rx_skbuff[i]) {
> @@ -1007,14 +1057,42 @@ static void stmmac_free_rx_buffers(struct stmmac_priv
> *priv, int i)
> }
>
> /**
> - * init_dma_desc_rings - init the RX/TX descriptor rings
> + * stmmac_free_tx_buffers - free RX dma buffers
> + * @priv: private structure
> + * @i: buffer index.
> + */
> +static void stmmac_free_tx_buffers(struct stmmac_priv *priv, int i)
> +{
> + if (priv->tx_skbuff_dma[i].buf) {
> + if (priv->tx_skbuff_dma[i].map_as_page)
> + dma_unmap_page(priv->device,
> + priv->tx_skbuff_dma[i].buf,
> + priv->tx_skbuff_dma[i].len,
> + DMA_TO_DEVICE);
> + else
> + dma_unmap_single(priv->device,
> + priv->tx_skbuff_dma[i].buf,
> + priv->tx_skbuff_dma[i].len,
> + DMA_TO_DEVICE);
> + }
> +
> + if (priv->tx_skbuff[i]) {
> + dev_kfree_skb_any(priv->tx_skbuff[i]);
> + priv->tx_skbuff[i] = NULL;
> + priv->tx_skbuff_dma[i].buf = 0;
> + priv->tx_skbuff_dma[i].map_as_page = false;
> + }
> +}
> +
> +/**
> + * init_dma_rx_desc_rings - init the RX descriptor rings
> * @dev: net device structure
> * @flags: gfp flag.
> - * Description: this function initializes the DMA RX/TX descriptors
> + * Description: this function initializes the DMA RX descriptors
> * and allocates the socket buffers. It supports the chained and ring
> * modes.
> */
> -static int init_dma_desc_rings(struct net_device *dev, gfp_t flags)
> +static int init_dma_rx_desc_rings(struct net_device *dev, gfp_t flags)
> {
> int i;
> struct stmmac_priv *priv = netdev_priv(dev);
> @@ -1030,8 +1108,7 @@ static int init_dma_desc_rings(struct net_device *dev,
> gfp_t flags)
> priv->dma_buf_sz = bfsize;
>
> netif_dbg(priv, probe, priv->dev,
> - "(%s) dma_rx_phy=0x%08x dma_tx_phy=0x%08x\n",
> - __func__, (u32)priv->dma_rx_phy, (u32)priv->dma_tx_phy);
> + "(%s) dma_rx_phy=0x%08x\n", __func__, (u32)priv->dma_rx_phy);
>
> /* RX INITIALIZATION */
> netif_dbg(priv, probe, priv->dev,
> @@ -1058,17 +1135,44 @@ static int init_dma_desc_rings(struct net_device
> *dev, gfp_t flags)
>
> /* Setup the chained descriptor addresses */
> if (priv->mode == STMMAC_CHAIN_MODE) {
> - if (priv->extend_desc) {
> + if (priv->extend_desc)
> priv->hw->mode->init(priv->dma_erx, priv->dma_rx_phy,
> DMA_RX_SIZE, 1);
> - priv->hw->mode->init(priv->dma_etx, priv->dma_tx_phy,
> - DMA_TX_SIZE, 1);
> - } else {
> + else
> priv->hw->mode->init(priv->dma_rx, priv->dma_rx_phy,
> DMA_RX_SIZE, 0);
> + }
> +
> + return 0;
> +err_init_rx_buffers:
> + while (--i >= 0)
> + stmmac_free_rx_buffers(priv, i);
> + return ret;
> +}
> +
> +/**
> + * init_dma_tx_desc_rings - init the TX descriptor rings
> + * @dev: net device structure.
> + * Description: this function initializes the DMA TX descriptors
> + * and allocates the socket buffers. It supports the chained and ring
> + * modes.
> + */
> +static int init_dma_tx_desc_rings(struct net_device *dev)
> +{
> + struct stmmac_priv *priv = netdev_priv(dev);
> + int i;
> +
> + netif_dbg(priv, probe, priv->dev,
> + "(%s) dma_tx_phy=0x%08x\n", __func__, (u32)priv->dma_rx_phy);
> +
> + /* Setup the chained descriptor addresses */
> + if (priv->mode == STMMAC_CHAIN_MODE) {
> + if (priv->extend_desc)
> + priv->hw->mode->init(priv->dma_etx, priv->dma_tx_phy,
> + DMA_TX_SIZE, 1);
> + else
> priv->hw->mode->init(priv->dma_tx, priv->dma_tx_phy,
> DMA_TX_SIZE, 0);
> - }
> }
>
> /* TX INITIALIZATION */
> @@ -1099,18 +1203,42 @@ static int init_dma_desc_rings(struct net_device
> *dev, gfp_t flags)
> priv->cur_tx = 0;
> netdev_reset_queue(priv->dev);
>
> + return 0;
> +}
> +
> +/**
> + * init_dma_desc_rings - init the RX/TX descriptor rings
> + * @dev: net device structure
> + * @flags: gfp flag.
> + * Description: this function initializes the DMA RX/TX descriptors
> + * and allocates the socket buffers. It supports the chained and ring
> + * modes.
> + */
> +static int init_dma_desc_rings(struct net_device *dev, gfp_t flags)
> +{
> + struct stmmac_priv *priv = netdev_priv(dev);
> + int ret;
> +
> + /* RX INITIALIZATION */
> + ret = init_dma_rx_desc_rings(dev, flags);
That comment already exists in init_dma_rx_desc_rings(). And even there
it doesn't provide any useful information, so might as well drop it.
> + if (ret)
> + return ret;
> +
> + /* TX INITIALIZATION */
> + ret = init_dma_tx_desc_rings(dev);
Same here.
[...]
> -static void free_dma_desc_resources(struct stmmac_priv *priv)
> +/**
> + * alloc_dma_desc_resources - alloc TX/RX resources.
> + * @priv: private structure
> + * Description: according to which descriptor can be used (extend or basic)
> + * this function allocates the resources for TX and RX paths. In case of
> + * reception, for example, it pre-allocated the RX socket buffer in order to
> + * allow zero-copy mechanism.
> + */
> +static int alloc_dma_desc_resources(struct stmmac_priv *priv)
> +{
> + /* RX Allocation */
> + int ret = alloc_dma_rx_desc_resources(priv);
And here.
> +
> + if (ret)
> + return ret;
> +
> + /* TX Allocation */
> + ret = alloc_dma_tx_desc_resources(priv);
And here.
None of the above comments are critical and this could be cleaned up in
follow-up patches, so:
Reviewed-by: Thierry Reding <tred...@nvidia.com>
It also doesn't break on Tegra186, so
Tested-by: Thierry Reding <tred...@nvidia.com>
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