From f83331bab149e29fa2c49cf102c0cd8c3f1ce9f9 Mon Sep 17 00:00:00 2001 From: Santosh Rastapur Date: Tue, 21 May 2013 04:21:29 +0000 Subject: [PATCH] cxgb3: Check and handle the dma mapping errors This patch adds checks at approprate places whether *dma_map*() call has succeeded or not. Signed-off-by: Santosh Rastapur Reviewed-by: Jay Fenlason Signed-off-by: David S. Miller --- drivers/net/ethernet/chelsio/cxgb3/sge.c | 105 ++++++++++++++++++----- 1 file changed, 82 insertions(+), 23 deletions(-) diff --git a/drivers/net/ethernet/chelsio/cxgb3/sge.c b/drivers/net/ethernet/chelsio/cxgb3/sge.c index f12e6b85a653..2fd773e267dc 100644 --- a/drivers/net/ethernet/chelsio/cxgb3/sge.c +++ b/drivers/net/ethernet/chelsio/cxgb3/sge.c @@ -455,6 +455,11 @@ 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; @@ -949,40 +954,75 @@ 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; +} + /** - * make_sgl - populate a scatter/gather list for a packet + * write_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 - * @pdev: the PCI device + * @addr: the list of the mapped addresses * - * Generates a scatter/gather list for the buffers that make up a packet + * Copies the 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 make_sgl(const struct sk_buff *skb, +static inline unsigned int write_sgl(const struct sk_buff *skb, struct sg_ent *sgp, unsigned char *start, - unsigned int len, struct pci_dev *pdev) + unsigned int len, const dma_addr_t *addr) { - dma_addr_t mapping; - unsigned int i, j = 0, nfrags; + unsigned int i, j = 0, k = 0, nfrags; if (len) { - mapping = pci_map_single(pdev, start, len, PCI_DMA_TODEVICE); sgp->len[0] = cpu_to_be32(len); - sgp->addr[0] = cpu_to_be64(mapping); - j = 1; + sgp->addr[j++] = cpu_to_be64(addr[k++]); } 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(mapping); + sgp->addr[j] = cpu_to_be64(addr[k++]); j ^= 1; if (j == 0) ++sgp; @@ -1138,7 +1178,7 @@ 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) + unsigned int compl, const dma_addr_t *addr) { unsigned int flits, sgl_flits, cntrl, tso_info; struct sg_ent *sgp, sgl[MAX_SKB_FRAGS / 2 + 1]; @@ -1196,7 +1236,7 @@ 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 = make_sgl(skb, sgp, skb->data, skb_headlen(skb), adap->pdev); + sgl_flits = write_sgl(skb, sgp, skb->data, skb_headlen(skb), addr); write_wr_hdr_sgl(ndesc, skb, d, pidx, q, sgl, flits, sgl_flits, gen, htonl(V_WR_OP(FW_WROPCODE_TUNNEL_TX_PKT) | compl), @@ -1227,6 +1267,7 @@ 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 @@ -1255,6 +1296,11 @@ 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); @@ -1312,7 +1358,7 @@ 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); + write_tx_pkt_wr(adap, skb, pi, pidx, gen, q, ndesc, compl, addr); check_ring_tx_db(adap, q); return NETDEV_TX_OK; } @@ -1578,7 +1624,8 @@ 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) + unsigned int gen, unsigned int ndesc, + const dma_addr_t *addr) { unsigned int sgl_flits, flits; struct work_request_hdr *from; @@ -1599,9 +1646,9 @@ 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 = make_sgl(skb, sgp, skb_transport_header(skb), + sgl_flits = write_sgl(skb, sgp, skb_transport_header(skb), skb->tail - skb->transport_header, - adap->pdev); + addr); if (need_skb_unmap()) { setup_deferred_unmapping(skb, adap->pdev, sgp, sgl_flits); skb->destructor = deferred_unmap_destructor; @@ -1659,6 +1706,11 @@ 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; @@ -1669,7 +1721,7 @@ again: reclaim_completed_tx(adap, q, TX_RECLAIM_CHUNK); } spin_unlock(&q->lock); - write_ofld_wr(adap, skb, q, pidx, gen, ndesc); + write_ofld_wr(adap, skb, q, pidx, gen, ndesc, (dma_addr_t *)skb->head); check_ring_tx_db(adap, q); return NET_XMIT_SUCCESS; } @@ -1687,6 +1739,7 @@ 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); @@ -1706,10 +1759,14 @@ 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; @@ -1717,7 +1774,8 @@ 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); + write_ofld_wr(adap, skb, q, pidx, gen, ndesc, + (dma_addr_t *)skb->head); spin_lock(&q->lock); } spin_unlock(&q->lock); @@ -1727,8 +1785,9 @@ again: reclaim_completed_tx(adap, q, TX_RECLAIM_CHUNK); set_bit(TXQ_LAST_PKT_DB, &q->flags); #endif wmb(); - t3_write_reg(adap, A_SG_KDOORBELL, - F_SELEGRCNTX | V_EGRCNTX(q->cntxt_id)); + if (likely(written)) + t3_write_reg(adap, A_SG_KDOORBELL, + F_SELEGRCNTX | V_EGRCNTX(q->cntxt_id)); } /** -- 2.20.1