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Message-Id: <1369146089-19060-3-git-send-email-vipul@chelsio.com>
Date: Tue, 21 May 2013 19:51:29 +0530
From: Vipul Pandya <vipul@...lsio.com>
To: netdev@...r.kernel.org
Cc: davem@...emloft.net, divy@...lsio.com, dm@...lsio.com,
santosh@...lsio.com, fenlason@...hat.com, vipul@...lsio.com
Subject: [PATCH net-next 2/2] cxgb3: Check and handle the dma mapping errors
From: Santosh Rastapur <santosh@...lsio.com>
This patch adds checks at approprate places whether *dma_map*() call has
succeeded or not.
Signed-off-by: Santosh Rastapur <santosh@...lsio.com>
Reviewed-by: Jay Fenlason <fenlason@...hat.com>
---
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 f12e6b8..2fd773e 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));
}
/**
--
1.8.0
--
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