On Tue, 2020-11-03 at 09:46 -0800, David Awogbemila wrote:
> From: Catherine Sullivan <csu...@google.com>
>
> Add support to use raw dma addresses in the rx path. Due to this new
> support we can alloc a new buffer instead of making a copy.
>
> RX buffers are handed to the networking stack and are
> re-allocated as needed, avoiding the need to use
> skb_copy_to_linear_data() as in "qpl" mode.
>
> Reviewed-by: Yangchun Fu <yangc...@google.com>
> Signed-off-by: Catherine Sullivan <csu...@google.com>
> Signed-off-by: David Awogbemila <awogbem...@google.com>
> ---
> drivers/net/ethernet/google/gve/gve.h | 9 +-
> drivers/net/ethernet/google/gve/gve_adminq.c | 14 +-
> drivers/net/ethernet/google/gve/gve_desc.h | 10 +-
> drivers/net/ethernet/google/gve/gve_main.c | 3 +-
> drivers/net/ethernet/google/gve/gve_rx.c | 220 +++++++++++++++
> ----
> 5 files changed, 203 insertions(+), 53 deletions(-)
>
...
> static inline u32 gve_num_rx_qpls(struct gve_priv *priv)
> {
> - return priv->rx_cfg.num_queues;
> + if (priv->raw_addressing)
> + return 0;
> + else
> + return priv->rx_cfg.num_queues;
else statement is redundant.
>
> static int gve_prefill_rx_pages(struct gve_rx_ring *rx)
> {
> struct gve_priv *priv = rx->gve;
> u32 slots;
> + int err;
> int i;
>
> /* Allocate one page per Rx queue slot. Each page is split into
> two
> @@ -71,12 +96,31 @@ static int gve_prefill_rx_pages(struct
> gve_rx_ring *rx)
> if (!rx->data.page_info)
> return -ENOMEM;
>
> - rx->data.qpl = gve_assign_rx_qpl(priv);
> -
> + if (!rx->data.raw_addressing)
> + rx->data.qpl = gve_assign_rx_qpl(priv);
> for (i = 0; i < slots; i++) {
> - struct page *page = rx->data.qpl->pages[i];
> - dma_addr_t addr = i * PAGE_SIZE;
> + struct page *page;
> + dma_addr_t addr;
> +
> + if (rx->data.raw_addressing) {
> + err = gve_alloc_page(priv, &priv->pdev->dev,
> &page,
> + &addr, DMA_FROM_DEVICE);
> + if (err) {
> + int j;
>
the code is skewed right, 5 level indentation is a lot.
you can just goto alloc_err; and handle the rewind on the exit path of
the function .
BTW you could split this loop to two independent flows if you utilize
gve_rx_alloc_buffer()
if (!raw_Addressing) {
page = rx->data.qpl->pages[i];
addr = i * PAGE_SIZE;
gve_setup_rx_buffer(...);
continue;
}
/* raw addressing mode */
err = gve_rx_alloc_buffer(...);
if (err)
goto alloc_err;
