Re: bnx2 fails to compile on parisc because of missing get_dma_ops()

Michael Chan
2010-06-17T12:54:42Z

FUJITA Tomonori wrote:

> From: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
> Date: Thu, 17 Jun 2010 13:06:15 +0900
> Subject: [PATCH] bnx2: fix dma_get_ops compilation breakage
>
> This removes dma_get_ops() prefetch optimization in bnx2.
>
> bnx2 uses dma_get_ops() to see if dma_sync_single_for_cpu() is
> noop. bnx2 does prefetch if it's noop.
>
> But dma_get_ops() isn't available on all the architectures (only the
> architectures that uses dma_map_ops struct have it). Using
> dma_get_ops() in drivers leads to compilation breakage on many
> archtectures.
>
> Currently, we don't have a way to see if dma_sync_single_for_cpu() is
> noop. If it can improve the performance notably, we can add the new
> DMA API for it.

This prefetch improves performance noticeably when the driver is
handling incoming 64-byte packets at a sustained rate.

>
> Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>

Acked-by: Michael Chan <mchan@broadcom.com>

Thanks.

> ---
> drivers/net/bnx2.c | 10 +---------
> 1 files changed, 1 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/net/bnx2.c b/drivers/net/bnx2.c
> index 949d7a9..b3305fc 100644
> --- a/drivers/net/bnx2.c
> +++ b/drivers/net/bnx2.c
> @@ -3073,7 +3073,6 @@ bnx2_rx_int(struct bnx2 *bp, struct
> bnx2_napi *bnapi, int budget)
> u16 hw_cons, sw_cons, sw_ring_cons, sw_prod, sw_ring_prod;
> struct l2_fhdr *rx_hdr;
> int rx_pkt = 0, pg_ring_used = 0;
> - struct pci_dev *pdev = bp->pdev;
>
> hw_cons = bnx2_get_hw_rx_cons(bnapi);
> sw_cons = rxr->rx_cons;
> @@ -3086,7 +3085,7 @@ bnx2_rx_int(struct bnx2 *bp, struct
> bnx2_napi *bnapi, int budget)
> while (sw_cons != hw_cons) {
> unsigned int len, hdr_len;
> u32 status;
> - struct sw_bd *rx_buf, *next_rx_buf;
> + struct sw_bd *rx_buf;
> struct sk_buff *skb;
> dma_addr_t dma_addr;
> u16 vtag = 0;
> @@ -3098,13 +3097,6 @@ bnx2_rx_int(struct bnx2 *bp, struct
> bnx2_napi *bnapi, int budget)
> rx_buf = &rxr->rx_buf_ring[sw_ring_cons];
> skb = rx_buf->skb;
> prefetchw(skb);
> -
> - if (!get_dma_ops(&pdev->dev)->sync_single_for_cpu) {
> - next_rx_buf =
> - &rxr->rx_buf_ring[
> -
> RX_RING_IDX(NEXT_RX_BD(sw_cons))];
> - prefetch(next_rx_buf->desc);
> - }
> rx_buf->skb = NULL;
>
> dma_addr = dma_unmap_addr(rx_buf, mapping);
> --
> 1.5.6.5
>
>
>