Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932646Ab2J2Ra5 (ORCPT ); Mon, 29 Oct 2012 13:30:57 -0400 Received: from mail-ea0-f174.google.com ([209.85.215.174]:56322 "EHLO mail-ea0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751430Ab2J2Ray (ORCPT ); Mon, 29 Oct 2012 13:30:54 -0400 Subject: [PATCH] vmxnet3: must split too big fragments From: Eric Dumazet To: Shreyas Bhatewara , David Miller Cc: "VMware, Inc." , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, jongman heo In-Reply-To: <1351021160.8609.2503.camel@edumazet-glaptop> References: <1103939870.6550404.1350986530909.JavaMail.root@vmware.com> <1351000246.8609.1926.camel@edumazet-glaptop> <1351021160.8609.2503.camel@edumazet-glaptop> Content-Type: text/plain; charset="UTF-8" Date: Mon, 29 Oct 2012 18:30:49 +0100 Message-ID: <1351531849.12280.54.camel@edumazet-glaptop> Mime-Version: 1.0 X-Mailer: Evolution 2.28.3 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3870 Lines: 118 From: Eric Dumazet vmxnet3 has a 16Kbytes limit per tx descriptor, that happened to work as long as we provided PAGE_SIZE fragments. Our stack can now build larger fragments, so we need to split them to the 16kbytes boundary. Signed-off-by: Eric Dumazet Reported-by: jongman heo Tested-by: jongman heo Cc: Shreyas Bhatewara --- drivers/net/vmxnet3/vmxnet3_drv.c | 65 +++++++++++++++++++--------- 1 file changed, 45 insertions(+), 20 deletions(-) diff --git a/drivers/net/vmxnet3/vmxnet3_drv.c b/drivers/net/vmxnet3/vmxnet3_drv.c index ce9d4f2..0ae1bcc 100644 --- a/drivers/net/vmxnet3/vmxnet3_drv.c +++ b/drivers/net/vmxnet3/vmxnet3_drv.c @@ -744,28 +744,43 @@ vmxnet3_map_pkt(struct sk_buff *skb, struct vmxnet3_tx_ctx *ctx, for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) { const struct skb_frag_struct *frag = &skb_shinfo(skb)->frags[i]; + u32 buf_size; - tbi = tq->buf_info + tq->tx_ring.next2fill; - tbi->map_type = VMXNET3_MAP_PAGE; - tbi->dma_addr = skb_frag_dma_map(&adapter->pdev->dev, frag, - 0, skb_frag_size(frag), - DMA_TO_DEVICE); + buf_offset = 0; + len = skb_frag_size(frag); + while (len) { + tbi = tq->buf_info + tq->tx_ring.next2fill; + if (len < VMXNET3_MAX_TX_BUF_SIZE) { + buf_size = len; + dw2 |= len; + } else { + buf_size = VMXNET3_MAX_TX_BUF_SIZE; + /* spec says that for TxDesc.len, 0 == 2^14 */ + } + tbi->map_type = VMXNET3_MAP_PAGE; + tbi->dma_addr = skb_frag_dma_map(&adapter->pdev->dev, frag, + buf_offset, buf_size, + DMA_TO_DEVICE); - tbi->len = skb_frag_size(frag); + tbi->len = buf_size; - gdesc = tq->tx_ring.base + tq->tx_ring.next2fill; - BUG_ON(gdesc->txd.gen == tq->tx_ring.gen); + gdesc = tq->tx_ring.base + tq->tx_ring.next2fill; + BUG_ON(gdesc->txd.gen == tq->tx_ring.gen); - gdesc->txd.addr = cpu_to_le64(tbi->dma_addr); - gdesc->dword[2] = cpu_to_le32(dw2 | skb_frag_size(frag)); - gdesc->dword[3] = 0; + gdesc->txd.addr = cpu_to_le64(tbi->dma_addr); + gdesc->dword[2] = cpu_to_le32(dw2); + gdesc->dword[3] = 0; - dev_dbg(&adapter->netdev->dev, - "txd[%u]: 0x%llu %u %u\n", - tq->tx_ring.next2fill, le64_to_cpu(gdesc->txd.addr), - le32_to_cpu(gdesc->dword[2]), gdesc->dword[3]); - vmxnet3_cmd_ring_adv_next2fill(&tq->tx_ring); - dw2 = tq->tx_ring.gen << VMXNET3_TXD_GEN_SHIFT; + dev_dbg(&adapter->netdev->dev, + "txd[%u]: 0x%llu %u %u\n", + tq->tx_ring.next2fill, le64_to_cpu(gdesc->txd.addr), + le32_to_cpu(gdesc->dword[2]), gdesc->dword[3]); + vmxnet3_cmd_ring_adv_next2fill(&tq->tx_ring); + dw2 = tq->tx_ring.gen << VMXNET3_TXD_GEN_SHIFT; + + len -= buf_size; + buf_offset += buf_size; + } } ctx->eop_txd = gdesc; @@ -886,6 +901,18 @@ vmxnet3_prepare_tso(struct sk_buff *skb, } } +static int txd_estimate(const struct sk_buff *skb) +{ + int count = VMXNET3_TXD_NEEDED(skb_headlen(skb)) + 1; + int i; + + for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) { + const struct skb_frag_struct *frag = &skb_shinfo(skb)->frags[i]; + + count += VMXNET3_TXD_NEEDED(skb_frag_size(frag)); + } + return count; +} /* * Transmits a pkt thru a given tq @@ -914,9 +941,7 @@ vmxnet3_tq_xmit(struct sk_buff *skb, struct vmxnet3_tx_queue *tq, union Vmxnet3_GenericDesc tempTxDesc; #endif - /* conservatively estimate # of descriptors to use */ - count = VMXNET3_TXD_NEEDED(skb_headlen(skb)) + - skb_shinfo(skb)->nr_frags + 1; + count = txd_estimate(skb); ctx.ipv4 = (vlan_get_protocol(skb) == cpu_to_be16(ETH_P_IP)); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/