On Wed, 30 Nov 2016 22:42:48 +0100 Gregory CLEMENT wrote:
> Until now the virtual address of the received buffer were stored in the
> cookie field of the rx descriptor. However, this field is 32-bits only
> which prevents to use the driver on a 64-bits architecture.
>
> With this patch the virtual address is stored in an array not shared with
> the hardware (no more need to use the DMA API). Thanks to this, it is
> possible to use cache contrary to the access of the rx descriptor member.
>
> The change is done in the swbm path only because the hwbm uses the cookie
> field, this also means that currently the hwbm is not usable in 64-bits.
>
> Signed-off-by: Gregory CLEMENT <gregory.clem...@free-electrons.com>
Reviewed-by: Jisheng Zhang <jszh...@marvell.com>
Thanks,
Jisheng
> ---
> drivers/net/ethernet/marvell/mvneta.c | 34 +++++++++++++++++++---------
> 1 file changed, 24 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/net/ethernet/marvell/mvneta.c
> b/drivers/net/ethernet/marvell/mvneta.c
> index f5319c50f8d9..92b9af14c352 100644
> --- a/drivers/net/ethernet/marvell/mvneta.c
> +++ b/drivers/net/ethernet/marvell/mvneta.c
> @@ -561,6 +561,9 @@ struct mvneta_rx_queue {
> u32 pkts_coal;
> u32 time_coal;
>
> + /* Virtual address of the RX buffer */
> + void **buf_virt_addr;
> +
> /* Virtual address of the RX DMA descriptors array */
> struct mvneta_rx_desc *descs;
>
> @@ -1573,10 +1576,14 @@ static void mvneta_tx_done_pkts_coal_set(struct
> mvneta_port *pp,
>
> /* Handle rx descriptor fill by setting buf_cookie and buf_phys_addr */
> static void mvneta_rx_desc_fill(struct mvneta_rx_desc *rx_desc,
> - u32 phys_addr, u32 cookie)
> + u32 phys_addr, void *virt_addr,
> + struct mvneta_rx_queue *rxq)
> {
> - rx_desc->buf_cookie = cookie;
> + int i;
> +
> rx_desc->buf_phys_addr = phys_addr;
> + i = rx_desc - rxq->descs;
> + rxq->buf_virt_addr[i] = virt_addr;
> }
>
> /* Decrement sent descriptors counter */
> @@ -1781,7 +1788,8 @@ EXPORT_SYMBOL_GPL(mvneta_frag_free);
>
> /* Refill processing for SW buffer management */
> static int mvneta_rx_refill(struct mvneta_port *pp,
> - struct mvneta_rx_desc *rx_desc)
> + struct mvneta_rx_desc *rx_desc,
> + struct mvneta_rx_queue *rxq)
>
> {
> dma_addr_t phys_addr;
> @@ -1799,7 +1807,7 @@ static int mvneta_rx_refill(struct mvneta_port *pp,
> return -ENOMEM;
> }
>
> - mvneta_rx_desc_fill(rx_desc, phys_addr, (u32)data);
> + mvneta_rx_desc_fill(rx_desc, phys_addr, data, rxq);
> return 0;
> }
>
> @@ -1861,7 +1869,7 @@ static void mvneta_rxq_drop_pkts(struct mvneta_port *pp,
>
> for (i = 0; i < rxq->size; i++) {
> struct mvneta_rx_desc *rx_desc = rxq->descs + i;
> - void *data = (void *)rx_desc->buf_cookie;
> + void *data = rxq->buf_virt_addr[i];
>
> dma_unmap_single(pp->dev->dev.parent, rx_desc->buf_phys_addr,
> MVNETA_RX_BUF_SIZE(pp->pkt_size),
> DMA_FROM_DEVICE);
> @@ -1894,12 +1902,13 @@ static int mvneta_rx_swbm(struct mvneta_port *pp, int
> rx_todo,
> unsigned char *data;
> dma_addr_t phys_addr;
> u32 rx_status, frag_size;
> - int rx_bytes, err;
> + int rx_bytes, err, index;
>
> rx_done++;
> rx_status = rx_desc->status;
> rx_bytes = rx_desc->data_size - (ETH_FCS_LEN + MVNETA_MH_SIZE);
> - data = (unsigned char *)rx_desc->buf_cookie;
> + index = rx_desc - rxq->descs;
> + data = rxq->buf_virt_addr[index];
> phys_addr = rx_desc->buf_phys_addr;
>
> if (!mvneta_rxq_desc_is_first_last(rx_status) ||
> @@ -1938,7 +1947,7 @@ static int mvneta_rx_swbm(struct mvneta_port *pp, int
> rx_todo,
> }
>
> /* Refill processing */
> - err = mvneta_rx_refill(pp, rx_desc);
> + err = mvneta_rx_refill(pp, rx_desc, rxq);
> if (err) {
> netdev_err(dev, "Linux processing - Can't refill\n");
> rxq->missed++;
> @@ -2020,7 +2029,7 @@ static int mvneta_rx_hwbm(struct mvneta_port *pp, int
> rx_todo,
> rx_done++;
> rx_status = rx_desc->status;
> rx_bytes = rx_desc->data_size - (ETH_FCS_LEN + MVNETA_MH_SIZE);
> - data = (unsigned char *)rx_desc->buf_cookie;
> + data = (u8 *)(uintptr_t)rx_desc->buf_cookie;
> phys_addr = rx_desc->buf_phys_addr;
> pool_id = MVNETA_RX_GET_BM_POOL_ID(rx_desc);
> bm_pool = &pp->bm_priv->bm_pools[pool_id];
> @@ -2716,7 +2725,7 @@ static int mvneta_rxq_fill(struct mvneta_port *pp,
> struct mvneta_rx_queue *rxq,
>
> for (i = 0; i < num; i++) {
> memset(rxq->descs + i, 0, sizeof(struct mvneta_rx_desc));
> - if (mvneta_rx_refill(pp, rxq->descs + i) != 0) {
> + if (mvneta_rx_refill(pp, rxq->descs + i, rxq) != 0) {
> netdev_err(pp->dev, "%s:rxq %d, %d of %d buffs
> filled\n",
> __func__, rxq->id, i, num);
> break;
> @@ -3865,6 +3874,11 @@ static int mvneta_init(struct device *dev, struct
> mvneta_port *pp)
> rxq->size = pp->rx_ring_size;
> rxq->pkts_coal = MVNETA_RX_COAL_PKTS;
> rxq->time_coal = MVNETA_RX_COAL_USEC;
> + rxq->buf_virt_addr = devm_kmalloc(pp->dev->dev.parent,
> + rxq->size * sizeof(void *),
> + GFP_KERNEL);
> + if (!rxq->buf_virt_addr)
> + return -ENOMEM;
> }
>
> return 0;
