From mboxrd@z Thu Jan 1 00:00:00 1970 From: Felix Fietkau Subject: [PATCH v7 3/9] bgmac: set received skb headroom to NET_SKB_PAD Date: Tue, 14 Apr 2015 12:07:56 +0200 Message-ID: <1429006082-23489-3-git-send-email-nbd@openwrt.org> References: <1429006082-23489-1-git-send-email-nbd@openwrt.org> Cc: zajec5@gmail.com, hauke@hauke-m.de To: netdev@vger.kernel.org Return-path: Received: from static.88-198-24-112.clients.your-server.de ([88.198.24.112]:54947 "EHLO nbd.name" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753928AbbDNKIH (ORCPT ); Tue, 14 Apr 2015 06:08:07 -0400 In-Reply-To: <1429006082-23489-1-git-send-email-nbd@openwrt.org> Sender: netdev-owner@vger.kernel.org List-ID: A packet buffer offset of 30 bytes is inefficient, because the first 2 bytes end up in a different cacheline. Signed-off-by: Felix Fietkau --- drivers/net/ethernet/broadcom/bgmac.c | 14 ++++++++------ drivers/net/ethernet/broadcom/bgmac.h | 4 +++- 2 files changed, 11 insertions(+), 7 deletions(-) diff --git a/drivers/net/ethernet/broadcom/bgmac.c b/drivers/net/ethernet/broadcom/bgmac.c index 9c3b2ff..424a68c 100644 --- a/drivers/net/ethernet/broadcom/bgmac.c +++ b/drivers/net/ethernet/broadcom/bgmac.c @@ -346,13 +346,13 @@ static int bgmac_dma_rx_skb_for_slot(struct bgmac *bgmac, return -ENOMEM; /* Poison - if everything goes fine, hardware will overwrite it */ - rx = buf; + rx = buf + BGMAC_RX_BUF_OFFSET; rx->len = cpu_to_le16(0xdead); rx->flags = cpu_to_le16(0xbeef); /* Map skb for the DMA */ - dma_addr = dma_map_single(dma_dev, buf, BGMAC_RX_BUF_SIZE, - DMA_FROM_DEVICE); + dma_addr = dma_map_single(dma_dev, buf + BGMAC_RX_BUF_OFFSET, + BGMAC_RX_BUF_SIZE, DMA_FROM_DEVICE); if (dma_mapping_error(dma_dev, dma_addr)) { bgmac_err(bgmac, "DMA mapping error\n"); put_page(virt_to_head_page(buf)); @@ -403,7 +403,7 @@ static int bgmac_dma_rx_read(struct bgmac *bgmac, struct bgmac_dma_ring *ring, while (ring->start != ring->end) { struct device *dma_dev = bgmac->core->dma_dev; struct bgmac_slot_info *slot = &ring->slots[ring->start]; - struct bgmac_rx_header *rx = slot->buf; + struct bgmac_rx_header *rx = slot->buf + BGMAC_RX_BUF_OFFSET; struct sk_buff *skb; void *buf = slot->buf; u16 len, flags; @@ -454,8 +454,10 @@ static int bgmac_dma_rx_read(struct bgmac *bgmac, struct bgmac_dma_ring *ring, BGMAC_RX_BUF_SIZE, DMA_FROM_DEVICE); skb = build_skb(buf, BGMAC_RX_ALLOC_SIZE); - skb_put(skb, BGMAC_RX_FRAME_OFFSET + len); - skb_pull(skb, BGMAC_RX_FRAME_OFFSET); + skb_put(skb, BGMAC_RX_FRAME_OFFSET + + BGMAC_RX_BUF_OFFSET + len); + skb_pull(skb, BGMAC_RX_FRAME_OFFSET + + BGMAC_RX_BUF_OFFSET); skb_checksum_none_assert(skb); skb->protocol = eth_type_trans(skb, bgmac->net_dev); diff --git a/drivers/net/ethernet/broadcom/bgmac.h b/drivers/net/ethernet/broadcom/bgmac.h index abd50d1..3db0d52 100644 --- a/drivers/net/ethernet/broadcom/bgmac.h +++ b/drivers/net/ethernet/broadcom/bgmac.h @@ -360,9 +360,11 @@ #define BGMAC_RX_HEADER_LEN 28 /* Last 24 bytes are unused. Well... */ #define BGMAC_RX_FRAME_OFFSET 30 /* There are 2 unused bytes between header and real data */ +#define BGMAC_RX_BUF_OFFSET (NET_SKB_PAD + NET_IP_ALIGN - \ + BGMAC_RX_FRAME_OFFSET) #define BGMAC_RX_MAX_FRAME_SIZE 1536 /* Copied from b44/tg3 */ #define BGMAC_RX_BUF_SIZE (BGMAC_RX_FRAME_OFFSET + BGMAC_RX_MAX_FRAME_SIZE) -#define BGMAC_RX_ALLOC_SIZE (SKB_DATA_ALIGN(BGMAC_RX_BUF_SIZE) + \ +#define BGMAC_RX_ALLOC_SIZE (SKB_DATA_ALIGN(BGMAC_RX_BUF_SIZE + BGMAC_RX_BUF_OFFSET) + \ SKB_DATA_ALIGN(sizeof(struct skb_shared_info))) #define BGMAC_BFL_ENETROBO 0x0010 /* has ephy roboswitch spi */ -- 2.2.2