Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760015Ab3HNP5v (ORCPT ); Wed, 14 Aug 2013 11:57:51 -0400 Received: from 99-65-72-227.uvs.sntcca.sbcglobal.net ([99.65.72.227]:43731 "EHLO stargate3.asicdesigners.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751008Ab3HNP5t (ORCPT ); Wed, 14 Aug 2013 11:57:49 -0400 Message-ID: <520BA8E4.3010406@chelsio.com> Date: Wed, 14 Aug 2013 08:57:24 -0700 From: Divy Le ray User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130804 Thunderbird/17.0.8 MIME-Version: 1.0 To: Alexey Kardashevskiy CC: "linuxppc-dev@lists.ozlabs.org" , "netdev@vger.kernel.org" , "linux-kernel@vger.kernel.org" , Linus Torvalds , Santosh Rastapur , Jay Fenlason , "David S. Miller" Subject: Re: [PATCH] Revert "cxgb3: Check and handle the dma mapping errors" References: <1376471941-2914-1-git-send-email-aik@ozlabs.ru> In-Reply-To: <1376471941-2914-1-git-send-email-aik@ozlabs.ru> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 9872 Lines: 273 On 08/14/2013 02:19 AM, Alexey Kardashevskiy wrote: > This reverts commit f83331bab149e29fa2c49cf102c0cd8c3f1ce9f9. > > As the tests PPC64 (powernv platform) show, IOMMU pages are leaking > when transferring big amount of small packets (<=64 bytes), > "ping -f" and waiting for 15 seconds is the simplest way to confirm the bug. > > Cc: Linus Torvalds > Cc: Santosh Rastapur > Cc: Jay Fenlason > Cc: David S. Miller > Cc: Divy Le ray > Signed-off-by: Alexey Kardashevskiy Acked-by: Divy Le Ray We are revisiting this patch in the light of the leak, and will repost once fixed. Cheers, Divy > --- > drivers/net/ethernet/chelsio/cxgb3/sge.c | 107 +++++++------------------------ > 1 file changed, 24 insertions(+), 83 deletions(-) > > diff --git a/drivers/net/ethernet/chelsio/cxgb3/sge.c b/drivers/net/ethernet/chelsio/cxgb3/sge.c > index 687ec4a..9c89dc8 100644 > --- a/drivers/net/ethernet/chelsio/cxgb3/sge.c > +++ b/drivers/net/ethernet/chelsio/cxgb3/sge.c > @@ -455,11 +455,6 @@ static int alloc_pg_chunk(struct adapter *adapter, struct sge_fl *q, > q->pg_chunk.offset = 0; > mapping = pci_map_page(adapter->pdev, q->pg_chunk.page, > 0, q->alloc_size, PCI_DMA_FROMDEVICE); > - if (unlikely(pci_dma_mapping_error(adapter->pdev, mapping))) { > - __free_pages(q->pg_chunk.page, order); > - q->pg_chunk.page = NULL; > - return -EIO; > - } > q->pg_chunk.mapping = mapping; > } > sd->pg_chunk = q->pg_chunk; > @@ -954,75 +949,40 @@ static inline unsigned int calc_tx_descs(const struct sk_buff *skb) > return flits_to_desc(flits); > } > > - > -/* map_skb - map a packet main body and its page fragments > - * @pdev: the PCI device > - * @skb: the packet > - * @addr: placeholder to save the mapped addresses > - * > - * map the main body of an sk_buff and its page fragments, if any. > - */ > -static int map_skb(struct pci_dev *pdev, const struct sk_buff *skb, > - dma_addr_t *addr) > -{ > - const skb_frag_t *fp, *end; > - const struct skb_shared_info *si; > - > - *addr = pci_map_single(pdev, skb->data, skb_headlen(skb), > - PCI_DMA_TODEVICE); > - if (pci_dma_mapping_error(pdev, *addr)) > - goto out_err; > - > - si = skb_shinfo(skb); > - end = &si->frags[si->nr_frags]; > - > - for (fp = si->frags; fp < end; fp++) { > - *++addr = skb_frag_dma_map(&pdev->dev, fp, 0, skb_frag_size(fp), > - DMA_TO_DEVICE); > - if (pci_dma_mapping_error(pdev, *addr)) > - goto unwind; > - } > - return 0; > - > -unwind: > - while (fp-- > si->frags) > - dma_unmap_page(&pdev->dev, *--addr, skb_frag_size(fp), > - DMA_TO_DEVICE); > - > - pci_unmap_single(pdev, addr[-1], skb_headlen(skb), PCI_DMA_TODEVICE); > -out_err: > - return -ENOMEM; > -} > - > /** > - * write_sgl - populate a scatter/gather list for a packet > + * make_sgl - populate a scatter/gather list for a packet > * @skb: the packet > * @sgp: the SGL to populate > * @start: start address of skb main body data to include in the SGL > * @len: length of skb main body data to include in the SGL > - * @addr: the list of the mapped addresses > + * @pdev: the PCI device > * > - * Copies the scatter/gather list for the buffers that make up a packet > + * Generates a scatter/gather list for the buffers that make up a packet > * and returns the SGL size in 8-byte words. The caller must size the SGL > * appropriately. > */ > -static inline unsigned int write_sgl(const struct sk_buff *skb, > +static inline unsigned int make_sgl(const struct sk_buff *skb, > struct sg_ent *sgp, unsigned char *start, > - unsigned int len, const dma_addr_t *addr) > + unsigned int len, struct pci_dev *pdev) > { > - unsigned int i, j = 0, k = 0, nfrags; > + dma_addr_t mapping; > + unsigned int i, j = 0, nfrags; > > if (len) { > + mapping = pci_map_single(pdev, start, len, PCI_DMA_TODEVICE); > sgp->len[0] = cpu_to_be32(len); > - sgp->addr[j++] = cpu_to_be64(addr[k++]); > + sgp->addr[0] = cpu_to_be64(mapping); > + j = 1; > } > > nfrags = skb_shinfo(skb)->nr_frags; > for (i = 0; i < nfrags; i++) { > const skb_frag_t *frag = &skb_shinfo(skb)->frags[i]; > > + mapping = skb_frag_dma_map(&pdev->dev, frag, 0, skb_frag_size(frag), > + DMA_TO_DEVICE); > sgp->len[j] = cpu_to_be32(skb_frag_size(frag)); > - sgp->addr[j] = cpu_to_be64(addr[k++]); > + sgp->addr[j] = cpu_to_be64(mapping); > j ^= 1; > if (j == 0) > ++sgp; > @@ -1178,7 +1138,7 @@ static void write_tx_pkt_wr(struct adapter *adap, struct sk_buff *skb, > const struct port_info *pi, > unsigned int pidx, unsigned int gen, > struct sge_txq *q, unsigned int ndesc, > - unsigned int compl, const dma_addr_t *addr) > + unsigned int compl) > { > unsigned int flits, sgl_flits, cntrl, tso_info; > struct sg_ent *sgp, sgl[MAX_SKB_FRAGS / 2 + 1]; > @@ -1236,7 +1196,7 @@ 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 = write_sgl(skb, sgp, skb->data, skb_headlen(skb), addr); > + sgl_flits = make_sgl(skb, sgp, skb->data, skb_headlen(skb), adap->pdev); > > write_wr_hdr_sgl(ndesc, skb, d, pidx, q, sgl, flits, sgl_flits, gen, > htonl(V_WR_OP(FW_WROPCODE_TUNNEL_TX_PKT) | compl), > @@ -1267,7 +1227,6 @@ netdev_tx_t t3_eth_xmit(struct sk_buff *skb, struct net_device *dev) > struct netdev_queue *txq; > struct sge_qset *qs; > struct sge_txq *q; > - dma_addr_t addr[MAX_SKB_FRAGS + 1]; > > /* > * The chip min packet length is 9 octets but play safe and reject > @@ -1296,11 +1255,6 @@ netdev_tx_t t3_eth_xmit(struct sk_buff *skb, struct net_device *dev) > return NETDEV_TX_BUSY; > } > > - if (unlikely(map_skb(adap->pdev, skb, addr) < 0)) { > - dev_kfree_skb(skb); > - return NETDEV_TX_OK; > - } > - > q->in_use += ndesc; > if (unlikely(credits - ndesc < q->stop_thres)) { > t3_stop_tx_queue(txq, qs, q); > @@ -1358,7 +1312,7 @@ netdev_tx_t t3_eth_xmit(struct sk_buff *skb, struct net_device *dev) > if (likely(!skb_shared(skb))) > skb_orphan(skb); > > - write_tx_pkt_wr(adap, skb, pi, pidx, gen, q, ndesc, compl, addr); > + write_tx_pkt_wr(adap, skb, pi, pidx, gen, q, ndesc, compl); > check_ring_tx_db(adap, q); > return NETDEV_TX_OK; > } > @@ -1623,8 +1577,7 @@ static void setup_deferred_unmapping(struct sk_buff *skb, struct pci_dev *pdev, > */ > static void write_ofld_wr(struct adapter *adap, struct sk_buff *skb, > struct sge_txq *q, unsigned int pidx, > - unsigned int gen, unsigned int ndesc, > - const dma_addr_t *addr) > + unsigned int gen, unsigned int ndesc) > { > unsigned int sgl_flits, flits; > struct work_request_hdr *from; > @@ -1645,9 +1598,9 @@ static void write_ofld_wr(struct adapter *adap, struct sk_buff *skb, > > flits = skb_transport_offset(skb) / 8; > sgp = ndesc == 1 ? (struct sg_ent *)&d->flit[flits] : sgl; > - sgl_flits = write_sgl(skb, sgp, skb_transport_header(skb), > - skb_tail_pointer(skb) - > - skb_transport_header(skb), addr); > + sgl_flits = make_sgl(skb, sgp, skb_transport_header(skb), > + skb->tail - skb->transport_header, > + adap->pdev); > if (need_skb_unmap()) { > setup_deferred_unmapping(skb, adap->pdev, sgp, sgl_flits); > skb->destructor = deferred_unmap_destructor; > @@ -1705,11 +1658,6 @@ again: reclaim_completed_tx(adap, q, TX_RECLAIM_CHUNK); > goto again; > } > > - if (map_skb(adap->pdev, skb, (dma_addr_t *)skb->head)) { > - spin_unlock(&q->lock); > - return NET_XMIT_SUCCESS; > - } > - > gen = q->gen; > q->in_use += ndesc; > pidx = q->pidx; > @@ -1720,7 +1668,7 @@ again: reclaim_completed_tx(adap, q, TX_RECLAIM_CHUNK); > } > spin_unlock(&q->lock); > > - write_ofld_wr(adap, skb, q, pidx, gen, ndesc, (dma_addr_t *)skb->head); > + write_ofld_wr(adap, skb, q, pidx, gen, ndesc); > check_ring_tx_db(adap, q); > return NET_XMIT_SUCCESS; > } > @@ -1738,7 +1686,6 @@ static void restart_offloadq(unsigned long data) > struct sge_txq *q = &qs->txq[TXQ_OFLD]; > const struct port_info *pi = netdev_priv(qs->netdev); > struct adapter *adap = pi->adapter; > - unsigned int written = 0; > > spin_lock(&q->lock); > again: reclaim_completed_tx(adap, q, TX_RECLAIM_CHUNK); > @@ -1758,14 +1705,10 @@ again: reclaim_completed_tx(adap, q, TX_RECLAIM_CHUNK); > break; > } > > - if (map_skb(adap->pdev, skb, (dma_addr_t *)skb->head)) > - break; > - > gen = q->gen; > q->in_use += ndesc; > pidx = q->pidx; > q->pidx += ndesc; > - written += ndesc; > if (q->pidx >= q->size) { > q->pidx -= q->size; > q->gen ^= 1; > @@ -1773,8 +1716,7 @@ again: reclaim_completed_tx(adap, q, TX_RECLAIM_CHUNK); > __skb_unlink(skb, &q->sendq); > spin_unlock(&q->lock); > > - write_ofld_wr(adap, skb, q, pidx, gen, ndesc, > - (dma_addr_t *)skb->head); > + write_ofld_wr(adap, skb, q, pidx, gen, ndesc); > spin_lock(&q->lock); > } > spin_unlock(&q->lock); > @@ -1784,9 +1726,8 @@ again: reclaim_completed_tx(adap, q, TX_RECLAIM_CHUNK); > set_bit(TXQ_LAST_PKT_DB, &q->flags); > #endif > wmb(); > - if (likely(written)) > - t3_write_reg(adap, A_SG_KDOORBELL, > - F_SELEGRCNTX | V_EGRCNTX(q->cntxt_id)); > + t3_write_reg(adap, A_SG_KDOORBELL, > + F_SELEGRCNTX | V_EGRCNTX(q->cntxt_id)); > } > > /** -- 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/