[PATCH 3.13 003/162] myri10ge: check for DMA mapping errors

From: Kamal Mostafa
Date: Thu Nov 06 2014 - 18:23:43 EST


3.13.11.11 -stable review patch. If anyone has any objections, please let me know.

------------------

From: Stanislaw Gruszka <sgruszka@xxxxxxxxxx>

[ Upstream commit 10545937e866ccdbb7ab583031dbdcc6b14e4eb4 ]

On IOMMU systems DMA mapping can fail, we need to check for
that possibility.

Signed-off-by: Stanislaw Gruszka <sgruszka@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Kamal Mostafa <kamal@xxxxxxxxxxxxx>
---
drivers/net/ethernet/myricom/myri10ge/myri10ge.c | 88 ++++++++++++++++--------
1 file changed, 58 insertions(+), 30 deletions(-)

diff --git a/drivers/net/ethernet/myricom/myri10ge/myri10ge.c b/drivers/net/ethernet/myricom/myri10ge/myri10ge.c
index 68026f7..4a474dd 100644
--- a/drivers/net/ethernet/myricom/myri10ge/myri10ge.c
+++ b/drivers/net/ethernet/myricom/myri10ge/myri10ge.c
@@ -872,6 +872,10 @@ static int myri10ge_dma_test(struct myri10ge_priv *mgp, int test_type)
return -ENOMEM;
dmatest_bus = pci_map_page(mgp->pdev, dmatest_page, 0, PAGE_SIZE,
DMA_BIDIRECTIONAL);
+ if (unlikely(pci_dma_mapping_error(mgp->pdev, dmatest_bus))) {
+ __free_page(dmatest_page);
+ return -ENOMEM;
+ }

/* Run a small DMA test.
* The magic multipliers to the length tell the firmware
@@ -1293,6 +1297,7 @@ myri10ge_alloc_rx_pages(struct myri10ge_priv *mgp, struct myri10ge_rx_buf *rx,
int bytes, int watchdog)
{
struct page *page;
+ dma_addr_t bus;
int idx;
#if MYRI10GE_ALLOC_SIZE > 4096
int end_offset;
@@ -1317,11 +1322,21 @@ myri10ge_alloc_rx_pages(struct myri10ge_priv *mgp, struct myri10ge_rx_buf *rx,
rx->watchdog_needed = 1;
return;
}
+
+ bus = pci_map_page(mgp->pdev, page, 0,
+ MYRI10GE_ALLOC_SIZE,
+ PCI_DMA_FROMDEVICE);
+ if (unlikely(pci_dma_mapping_error(mgp->pdev, bus))) {
+ __free_pages(page, MYRI10GE_ALLOC_ORDER);
+ if (rx->fill_cnt - rx->cnt < 16)
+ rx->watchdog_needed = 1;
+ return;
+ }
+
rx->page = page;
rx->page_offset = 0;
- rx->bus = pci_map_page(mgp->pdev, page, 0,
- MYRI10GE_ALLOC_SIZE,
- PCI_DMA_FROMDEVICE);
+ rx->bus = bus;
+
}
rx->info[idx].page = rx->page;
rx->info[idx].page_offset = rx->page_offset;
@@ -2765,6 +2780,35 @@ myri10ge_submit_req(struct myri10ge_tx_buf *tx, struct mcp_kreq_ether_send *src,
mb();
}

+static void myri10ge_unmap_tx_dma(struct myri10ge_priv *mgp,
+ struct myri10ge_tx_buf *tx, int idx)
+{
+ unsigned int len;
+ int last_idx;
+
+ /* Free any DMA resources we've alloced and clear out the skb slot */
+ last_idx = (idx + 1) & tx->mask;
+ idx = tx->req & tx->mask;
+ do {
+ len = dma_unmap_len(&tx->info[idx], len);
+ if (len) {
+ if (tx->info[idx].skb != NULL)
+ pci_unmap_single(mgp->pdev,
+ dma_unmap_addr(&tx->info[idx],
+ bus), len,
+ PCI_DMA_TODEVICE);
+ else
+ pci_unmap_page(mgp->pdev,
+ dma_unmap_addr(&tx->info[idx],
+ bus), len,
+ PCI_DMA_TODEVICE);
+ dma_unmap_len_set(&tx->info[idx], len, 0);
+ tx->info[idx].skb = NULL;
+ }
+ idx = (idx + 1) & tx->mask;
+ } while (idx != last_idx);
+}
+
/*
* Transmit a packet. We need to split the packet so that a single
* segment does not cross myri10ge->tx_boundary, so this makes segment
@@ -2788,7 +2832,7 @@ static netdev_tx_t myri10ge_xmit(struct sk_buff *skb,
u32 low;
__be32 high_swapped;
unsigned int len;
- int idx, last_idx, avail, frag_cnt, frag_idx, count, mss, max_segments;
+ int idx, avail, frag_cnt, frag_idx, count, mss, max_segments;
u16 pseudo_hdr_offset, cksum_offset, queue;
int cum_len, seglen, boundary, rdma_count;
u8 flags, odd_flag;
@@ -2885,9 +2929,12 @@ again:

/* map the skb for DMA */
len = skb_headlen(skb);
+ bus = pci_map_single(mgp->pdev, skb->data, len, PCI_DMA_TODEVICE);
+ if (unlikely(pci_dma_mapping_error(mgp->pdev, bus)))
+ goto drop;
+
idx = tx->req & tx->mask;
tx->info[idx].skb = skb;
- bus = pci_map_single(mgp->pdev, skb->data, len, PCI_DMA_TODEVICE);
dma_unmap_addr_set(&tx->info[idx], bus, bus);
dma_unmap_len_set(&tx->info[idx], len, len);

@@ -2986,12 +3033,16 @@ again:
break;

/* map next fragment for DMA */
- idx = (count + tx->req) & tx->mask;
frag = &skb_shinfo(skb)->frags[frag_idx];
frag_idx++;
len = skb_frag_size(frag);
bus = skb_frag_dma_map(&mgp->pdev->dev, frag, 0, len,
DMA_TO_DEVICE);
+ if (unlikely(pci_dma_mapping_error(mgp->pdev, bus))) {
+ myri10ge_unmap_tx_dma(mgp, tx, idx);
+ goto drop;
+ }
+ idx = (count + tx->req) & tx->mask;
dma_unmap_addr_set(&tx->info[idx], bus, bus);
dma_unmap_len_set(&tx->info[idx], len, len);
}
@@ -3022,31 +3073,8 @@ again:
return NETDEV_TX_OK;

abort_linearize:
- /* Free any DMA resources we've alloced and clear out the skb
- * slot so as to not trip up assertions, and to avoid a
- * double-free if linearizing fails */
+ myri10ge_unmap_tx_dma(mgp, tx, idx);

- last_idx = (idx + 1) & tx->mask;
- idx = tx->req & tx->mask;
- tx->info[idx].skb = NULL;
- do {
- len = dma_unmap_len(&tx->info[idx], len);
- if (len) {
- if (tx->info[idx].skb != NULL)
- pci_unmap_single(mgp->pdev,
- dma_unmap_addr(&tx->info[idx],
- bus), len,
- PCI_DMA_TODEVICE);
- else
- pci_unmap_page(mgp->pdev,
- dma_unmap_addr(&tx->info[idx],
- bus), len,
- PCI_DMA_TODEVICE);
- dma_unmap_len_set(&tx->info[idx], len, 0);
- tx->info[idx].skb = NULL;
- }
- idx = (idx + 1) & tx->mask;
- } while (idx != last_idx);
if (skb_is_gso(skb)) {
netdev_err(mgp->dev, "TSO but wanted to linearize?!?!?\n");
goto drop;
--
1.9.1

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