Fix iwlan DMA mapping direction
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>
diff --git a/drivers/net/wireless/iwlwifi/iwl-tx.c b/drivers/net/wireless/iwlwifi/iwl-tx.c
index b0ee86c..ab13ff2 100644
--- a/drivers/net/wireless/iwlwifi/iwl-tx.c
+++ b/drivers/net/wireless/iwlwifi/iwl-tx.c
@@ -148,7 +148,7 @@
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 @@
* 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 @@
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 @@
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)) {