Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933792AbXKPTY0 (ORCPT ); Fri, 16 Nov 2007 14:24:26 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932378AbXKPTWN (ORCPT ); Fri, 16 Nov 2007 14:22:13 -0500 Received: from stargate.chelsio.com ([12.22.49.110]:18109 "EHLO stargate.chelsio.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757951AbXKPTWK (ORCPT ); Fri, 16 Nov 2007 14:22:10 -0500 From: Divy Le Ray Subject: [PATCH 6/9] cxgb3 - fix interaction with pktgen To: jeff@garzik.org Cc: davem@davemloft.net, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, swise@opengridcomputing.com, wenxiong@us.ibm.com Date: Fri, 16 Nov 2007 11:22:05 -0800 Message-ID: <20071116192205.31115.1659.stgit@speedy5> User-Agent: StGIT/0.12 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 7381 Lines: 196 From: Divy Le Ray Do not use skb->cb to stash unmap info, save the info to the descriptor state. Signed-off-by: Divy Le Ray --- drivers/net/cxgb3/sge.c | 82 +++++++++++++++++++++++------------------------ 1 files changed, 40 insertions(+), 42 deletions(-) diff --git a/drivers/net/cxgb3/sge.c b/drivers/net/cxgb3/sge.c index c15e43a..7b13d8a 100644 --- a/drivers/net/cxgb3/sge.c +++ b/drivers/net/cxgb3/sge.c @@ -91,6 +91,10 @@ struct rx_desc { struct tx_sw_desc { /* SW state per Tx descriptor */ struct sk_buff *skb; + u8 eop; /* set if last descriptor for packet */ + u8 addr_idx; /* buffer index of first SGL entry in descriptor */ + u8 fragidx; /* first page fragment associated with descriptor */ + s8 sflit; /* start flit of first SGL entry in descriptor */ }; struct rx_sw_desc { /* SW state per Rx descriptor */ @@ -109,13 +113,6 @@ struct rsp_desc { /* response queue descriptor */ u8 intr_gen; }; -struct unmap_info { /* packet unmapping info, overlays skb->cb */ - int sflit; /* start flit of first SGL entry in Tx descriptor */ - u16 fragidx; /* first page fragment in current Tx descriptor */ - u16 addr_idx; /* buffer index of first SGL entry in descriptor */ - u32 len; /* mapped length of skb main body */ -}; - /* * Holds unmapping information for Tx packets that need deferred unmapping. * This structure lives at skb->head and must be allocated by callers. @@ -209,32 +206,36 @@ static inline int need_skb_unmap(void) * * Unmap the main body of an sk_buff and its page fragments, if any. * Because of the fairly complicated structure of our SGLs and the desire - * to conserve space for metadata, we keep the information necessary to - * unmap an sk_buff partly in the sk_buff itself (in its cb), and partly - * in the Tx descriptors (the physical addresses of the various data - * buffers). The send functions initialize the state in skb->cb so we - * can unmap the buffers held in the first Tx descriptor here, and we - * have enough information at this point to update the state for the next - * Tx descriptor. + * to conserve space for metadata, the information necessary to unmap an + * sk_buff is spread across the sk_buff itself (buffer lengths), the HW Tx + * descriptors (the physical addresses of the various data buffers), and + * the SW descriptor state (assorted indices). The send functions + * initialize the indices for the first packet descriptor so we can unmap + * the buffers held in the first Tx descriptor here, and we have enough + * information at this point to set the state for the next Tx descriptor. + * + * Note that it is possible to clean up the first descriptor of a packet + * before the send routines have written the next descriptors, but this + * race does not cause any problem. We just end up writing the unmapping + * info for the descriptor first. */ static inline void unmap_skb(struct sk_buff *skb, struct sge_txq *q, unsigned int cidx, struct pci_dev *pdev) { const struct sg_ent *sgp; - struct unmap_info *ui = (struct unmap_info *)skb->cb; - int nfrags, frag_idx, curflit, j = ui->addr_idx; + struct tx_sw_desc *d = &q->sdesc[cidx]; + int nfrags, frag_idx, curflit, j = d->addr_idx; - sgp = (struct sg_ent *)&q->desc[cidx].flit[ui->sflit]; + sgp = (struct sg_ent *)&q->desc[cidx].flit[d->sflit]; + frag_idx = d->fragidx; - if (ui->len) { - pci_unmap_single(pdev, be64_to_cpu(sgp->addr[0]), ui->len, - PCI_DMA_TODEVICE); - ui->len = 0; /* so we know for next descriptor for this skb */ + if (frag_idx == 0 && skb_headlen(skb)) { + pci_unmap_single(pdev, be64_to_cpu(sgp->addr[0]), + skb_headlen(skb), PCI_DMA_TODEVICE); j = 1; } - frag_idx = ui->fragidx; - curflit = ui->sflit + 1 + j; + curflit = d->sflit + 1 + j; nfrags = skb_shinfo(skb)->nr_frags; while (frag_idx < nfrags && curflit < WR_FLITS) { @@ -250,10 +251,11 @@ static inline void unmap_skb(struct sk_buff *skb, struct sge_txq *q, frag_idx++; } - if (frag_idx < nfrags) { /* SGL continues into next Tx descriptor */ - ui->fragidx = frag_idx; - ui->addr_idx = j; - ui->sflit = curflit - WR_FLITS - j; /* sflit can be -1 */ + if (frag_idx < nfrags) { /* SGL continues into next Tx descriptor */ + d = cidx + 1 == q->size ? q->sdesc : d + 1; + d->fragidx = frag_idx; + d->addr_idx = j; + d->sflit = curflit - WR_FLITS - j; /* sflit can be -1 */ } } @@ -281,7 +283,7 @@ static void free_tx_desc(struct adapter *adapter, struct sge_txq *q, if (d->skb) { /* an SGL is present */ if (need_unmap) unmap_skb(d->skb, q, cidx, pdev); - if (d->skb->priority == cidx) + if (d->eop) kfree_skb(d->skb); } ++d; @@ -912,15 +914,13 @@ static void write_wr_hdr_sgl(unsigned int ndesc, struct sk_buff *skb, sd->skb = skb; if (need_skb_unmap()) { - struct unmap_info *ui = (struct unmap_info *)skb->cb; - - ui->fragidx = 0; - ui->addr_idx = 0; - ui->sflit = flits; + sd->fragidx = 0; + sd->addr_idx = 0; + sd->sflit = flits; } if (likely(ndesc == 1)) { - skb->priority = pidx; + sd->eop = 1; wrp->wr_hi = htonl(F_WR_SOP | F_WR_EOP | V_WR_DATATYPE(1) | V_WR_SGLSFLT(flits)) | wr_hi; wmb(); @@ -948,6 +948,7 @@ static void write_wr_hdr_sgl(unsigned int ndesc, struct sk_buff *skb, fp += avail; d++; + sd->eop = 0; sd++; if (++pidx == q->size) { pidx = 0; @@ -966,7 +967,7 @@ static void write_wr_hdr_sgl(unsigned int ndesc, struct sk_buff *skb, wr_gen2(d, gen); flits = 1; } - skb->priority = pidx; + sd->eop = 1; wrp->wr_hi |= htonl(F_WR_EOP); wmb(); wp->wr_lo = htonl(V_WR_LEN(WR_FLITS) | V_WR_GEN(ogen)) | wr_lo; @@ -1051,8 +1052,6 @@ static void write_tx_pkt_wr(struct adapter *adap, struct sk_buff *skb, sgp = ndesc == 1 ? (struct sg_ent *)&d->flit[flits] : sgl; sgl_flits = make_sgl(skb, sgp, skb->data, skb_headlen(skb), adap->pdev); - if (need_skb_unmap()) - ((struct unmap_info *)skb->cb)->len = skb_headlen(skb); write_wr_hdr_sgl(ndesc, skb, d, pidx, q, sgl, flits, sgl_flits, gen, htonl(V_WR_OP(FW_WROPCODE_TUNNEL_TX_PKT) | compl), @@ -1380,13 +1379,14 @@ static void deferred_unmap_destructor(struct sk_buff *skb) const dma_addr_t *p; const struct skb_shared_info *si; const struct deferred_unmap_info *dui; - const struct unmap_info *ui = (struct unmap_info *)skb->cb; dui = (struct deferred_unmap_info *)skb->head; p = dui->addr; - if (ui->len) - pci_unmap_single(dui->pdev, *p++, ui->len, PCI_DMA_TODEVICE); + if (skb->tail - skb->transport_header) + pci_unmap_single(dui->pdev, *p++, + skb->tail - skb->transport_header, + PCI_DMA_TODEVICE); si = skb_shinfo(skb); for (i = 0; i < si->nr_frags; i++) @@ -1451,8 +1451,6 @@ static void write_ofld_wr(struct adapter *adap, struct sk_buff *skb, if (need_skb_unmap()) { setup_deferred_unmapping(skb, adap->pdev, sgp, sgl_flits); skb->destructor = deferred_unmap_destructor; - ((struct unmap_info *)skb->cb)->len = (skb->tail - - skb->transport_header); } write_wr_hdr_sgl(ndesc, skb, d, pidx, q, sgl, flits, sgl_flits, - 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/