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Fix iwlan DMA mapping direction

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When iwlan runs on IOMMU, IOMMU generates a lot of PTE write faults
because PTE write bit is not set on some of PTE's.  This is because
iwlan driver calls DMA mapping with PCI_DMA_TODEVICE which is read only
in mapping PTE.  But iwlan device actually writes to the mapped page to
update its contents.  This issue is not exposed in swiotlb.  But VT-d
hardware can capture this fault and stop the fault transaction.

The following patch fixes the issue.

Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Reviewed-by: Bhavesh Davda <bhavesh@vmware.com>
Tested-by: Chris Wright <chrisw@sous-sol.org>
Acked-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Fenghua Yu 2009-02-25 14:06:26 +09:00 committed by Linus Torvalds
parent 694593e337
commit 6aa03ab069
1 changed files with 4 additions and 4 deletions
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8
drivers/net/wireless/iwlwifi/iwl-tx.c
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@ -148,7 +148,7 @@ static void iwl_hw_txq_free_tfd(struct iwl_priv *priv, struct iwl_tx_queue *txq)
pci_unmap_single(dev,
pci_unmap_addr(&txq->cmd[index]->meta, mapping),
pci_unmap_len(&txq->cmd[index]->meta, len),
PCI_DMA_TODEVICE);
PCI_DMA_BIDIRECTIONAL);
/* Unmap chunks, if any. */
for (i = 1; i < num_tbs; i++) {
@ -964,7 +964,7 @@ int iwl_tx_skb(struct iwl_priv *priv, struct sk_buff *skb)
* within command buffer array. */
txcmd_phys = pci_map_single(priv->pci_dev,
out_cmd, sizeof(struct iwl_cmd),
PCI_DMA_TODEVICE);
PCI_DMA_BIDIRECTIONAL);
pci_unmap_addr_set(&out_cmd->meta, mapping, txcmd_phys);
pci_unmap_len_set(&out_cmd->meta, len, sizeof(struct iwl_cmd));
/* Add buffer containing Tx command and MAC(!) header to TFD's
@ -1115,7 +1115,7 @@ int iwl_enqueue_hcmd(struct iwl_priv *priv, struct iwl_host_cmd *cmd)
IWL_MAX_SCAN_SIZE : sizeof(struct iwl_cmd);
phys_addr = pci_map_single(priv->pci_dev, out_cmd,
len, PCI_DMA_TODEVICE);
len, PCI_DMA_BIDIRECTIONAL);
pci_unmap_addr_set(&out_cmd->meta, mapping, phys_addr);
pci_unmap_len_set(&out_cmd->meta, len, len);
phys_addr += offsetof(struct iwl_cmd, hdr);
@ -1212,7 +1212,7 @@ static void iwl_hcmd_queue_reclaim(struct iwl_priv *priv, int txq_id,
pci_unmap_single(priv->pci_dev,
pci_unmap_addr(&txq->cmd[cmd_idx]->meta, mapping),
pci_unmap_len(&txq->cmd[cmd_idx]->meta, len),
PCI_DMA_TODEVICE);
PCI_DMA_BIDIRECTIONAL);
for (idx = iwl_queue_inc_wrap(idx, q->n_bd); q->read_ptr != idx;
q->read_ptr = iwl_queue_inc_wrap(q->read_ptr, q->n_bd)) {