[net-next PATCH 2/2] e1000: fix unmap bug

From: Jeff Kirsher
Date: Mon Mar 02 2009 - 18:50:55 EST


From: Jesse Brandeburg <jesse.brandeburg@xxxxxxxxx>

This is in reference to the issue shown in kerneloops (search e1000 unmap)

The e1000 transmit code was calling pci_unmap_page on dma handles that it
might have called pci_map_single on.

Same bug as e1000e

Signed-off-by: Jesse Brandeburg <jesse.brandeburg@xxxxxxxxx>
Acked-by: Bruce Allan <bruce.w.allan@xxxxxxxxx>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@xxxxxxxxx>
---

drivers/net/e1000/e1000_main.c | 51 +++++++++++++++++++++-------------------
1 files changed, 27 insertions(+), 24 deletions(-)

diff --git a/drivers/net/e1000/e1000_main.c b/drivers/net/e1000/e1000_main.c
index 61b56ca..1f390ce 100644
--- a/drivers/net/e1000/e1000_main.c
+++ b/drivers/net/e1000/e1000_main.c
@@ -2049,14 +2049,10 @@ void e1000_free_all_tx_resources(struct e1000_adapter *adapter)
static void e1000_unmap_and_free_tx_resource(struct e1000_adapter *adapter,
struct e1000_buffer *buffer_info)
{
- if (buffer_info->dma) {
- pci_unmap_page(adapter->pdev,
- buffer_info->dma,
- buffer_info->length,
- PCI_DMA_TODEVICE);
- buffer_info->dma = 0;
- }
+ buffer_info->dma = 0;
if (buffer_info->skb) {
+ skb_dma_unmap(&adapter->pdev->dev, buffer_info->skb,
+ DMA_TO_DEVICE);
dev_kfree_skb_any(buffer_info->skb);
buffer_info->skb = NULL;
}
@@ -2907,16 +2903,24 @@ static int e1000_tx_map(struct e1000_adapter *adapter,
unsigned int mss)
{
struct e1000_hw *hw = &adapter->hw;
- struct e1000_buffer *buffer_info;
- unsigned int len = skb->len;
- unsigned int offset = 0, size, count = 0, i;
+ unsigned int len = skb_headlen(skb);
+ unsigned int offset, size, count = 0, i;
unsigned int f;
- len -= skb->data_len;
+ dma_addr_t map;

i = tx_ring->next_to_use;

+ if (skb_dma_map(&adapter->pdev->dev, skb, DMA_TO_DEVICE)) {
+ dev_err(&adapter->pdev->dev, "TX DMA map failed\n");
+ dev_kfree_skb(skb);
+ return -2;
+ }
+
+ map = skb_shinfo(skb)->dma_maps[0];
+ offset = 0;
+
while (len) {
- buffer_info = &tx_ring->buffer_info[i];
+ struct e1000_buffer *buffer_info = &tx_ring->buffer_info[i];
size = min(len, max_per_txd);
/* Workaround for Controller erratum --
* descriptor for non-tso packet in a linear SKB that follows a
@@ -2949,11 +2953,7 @@ static int e1000_tx_map(struct e1000_adapter *adapter,
size -= 4;

buffer_info->length = size;
- buffer_info->dma =
- pci_map_single(adapter->pdev,
- skb->data + offset,
- size,
- PCI_DMA_TODEVICE);
+ buffer_info->dma = map + offset;
buffer_info->time_stamp = jiffies;
buffer_info->next_to_watch = i;

@@ -2968,9 +2968,11 @@ static int e1000_tx_map(struct e1000_adapter *adapter,

frag = &skb_shinfo(skb)->frags[f];
len = frag->size;
- offset = frag->page_offset;
+ map = skb_shinfo(skb)->dma_maps[f + 1];
+ offset = 0;

while (len) {
+ struct e1000_buffer *buffer_info;
buffer_info = &tx_ring->buffer_info[i];
size = min(len, max_per_txd);
/* Workaround for premature desc write-backs
@@ -2986,12 +2988,7 @@ static int e1000_tx_map(struct e1000_adapter *adapter,
size -= 4;

buffer_info->length = size;
- buffer_info->dma =
- pci_map_page(adapter->pdev,
- frag->page,
- offset,
- size,
- PCI_DMA_TODEVICE);
+ buffer_info->dma = map + offset;
buffer_info->time_stamp = jiffies;
buffer_info->next_to_watch = i;

@@ -3005,6 +3002,7 @@ static int e1000_tx_map(struct e1000_adapter *adapter,
i = (i == 0) ? tx_ring->count - 1 : i - 1;
tx_ring->buffer_info[i].skb = skb;
tx_ring->buffer_info[first].next_to_watch = i;
+ smp_wmb();

return count;
}
@@ -3844,6 +3842,11 @@ static bool e1000_clean_tx_irq(struct e1000_adapter *adapter,
/* Detect a transmit hang in hardware, this serializes the
* check with the clearing of time_stamp and movement of i */
adapter->detect_tx_hung = false;
+ /*
+ * read barrier to make sure that the ->dma member and time
+ * stamp are updated fully
+ */
+ smp_rmb();
if (tx_ring->buffer_info[eop].dma &&
time_after(jiffies, tx_ring->buffer_info[eop].time_stamp +
(adapter->tx_timeout_factor * HZ))

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/