redonkable/alistair23-linux
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ixgbe: Fix DMA mapping/unmapping issues when HWRSC is enabled on IOMMU enabled kernels

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Work around 82599 HW issue when HWRSC is enabled on IOMMU enabled
kernels. 82599 HW is updating the header information after setting the
descriptor to done, resulting DMA mapping/unmapping issues on IOMMU
enabled systems. To work around the issue delay unmapping of first packet
that carries the header information until end of packet is reached.

Signed-off-by: Mallikarjuna R Chilakala <mallikarjuna.chilakala@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Mallikarjuna R Chilakala 2010-02-25 23:14:37 +00:00 committed by David S. Miller
parent 41a655ba56
commit 43634e820e
1 changed files with 29 additions and 3 deletions
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32
drivers/net/ixgbe/ixgbe_main.c
View file

@ -818,6 +818,12 @@ static inline struct sk_buff *ixgbe_transform_rsc_queue(struct sk_buff *skb,
return skb;
}
struct ixgbe_rsc_cb {
dma_addr_t dma;
};
#define IXGBE_RSC_CB(skb) ((struct ixgbe_rsc_cb *)(skb)->cb)
static bool ixgbe_clean_rx_irq(struct ixgbe_q_vector *q_vector,
struct ixgbe_ring *rx_ring,
int *work_done, int work_to_do)
@ -867,9 +873,21 @@ static bool ixgbe_clean_rx_irq(struct ixgbe_q_vector *q_vector,
rx_buffer_info->skb = NULL;
if (rx_buffer_info->dma) {
pci_unmap_single(pdev, rx_buffer_info->dma,
rx_ring->rx_buf_len,
PCI_DMA_FROMDEVICE);
if ((adapter->flags2 & IXGBE_FLAG2_RSC_ENABLED) &&
(!(staterr & IXGBE_RXD_STAT_EOP)) &&
(!(skb->prev)))
/*
* When HWRSC is enabled, delay unmapping
* of the first packet. It carries the
* header information, HW may still
* access the header after the writeback.
* Only unmap it when EOP is reached
*/
IXGBE_RSC_CB(skb)->dma = rx_buffer_info->dma;
else
pci_unmap_single(pdev, rx_buffer_info->dma,
rx_ring->rx_buf_len,
PCI_DMA_FROMDEVICE);
rx_buffer_info->dma = 0;
skb_put(skb, len);
}
@ -917,6 +935,10 @@ static bool ixgbe_clean_rx_irq(struct ixgbe_q_vector *q_vector,
if (skb->prev)
skb = ixgbe_transform_rsc_queue(skb, &(rx_ring->rsc_count));
if (adapter->flags2 & IXGBE_FLAG2_RSC_ENABLED) {
if (IXGBE_RSC_CB(skb)->dma)
pci_unmap_single(pdev, IXGBE_RSC_CB(skb)->dma,
rx_ring->rx_buf_len,
PCI_DMA_FROMDEVICE);
if (rx_ring->flags & IXGBE_RING_RX_PS_ENABLED)
rx_ring->rsc_count += skb_shinfo(skb)->nr_frags;
else
@ -3104,6 +3126,10 @@ static void ixgbe_clean_rx_ring(struct ixgbe_adapter *adapter,
rx_buffer_info->skb = NULL;
do {
struct sk_buff *this = skb;
if (IXGBE_RSC_CB(this)->dma)
pci_unmap_single(pdev, IXGBE_RSC_CB(this)->dma,
rx_ring->rx_buf_len,
PCI_DMA_FROMDEVICE);
skb = skb->prev;
dev_kfree_skb(this);
} while (skb);