iommu sg merging: PCI: add device_dma_parameters support

This adds struct device_dma_parameters in struct pci_dev and properly
sets up a pointer in struct device.

The default max_segment_size is set to 64K, same to the block layer's
default value.

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Mostly-acked-by: Jeff Garzik <jeff@garzik.org>
Cc: James Bottomley <James.Bottomley@steeleye.com>
Acked-by: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

2 files changed, 11 insertions, 0 deletions

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 04aac7782468..be97090ddf32 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -1451,6 +1451,14 @@ pci_set_consistent_dma_mask(struct pci_dev *dev, u64 mask)
 }
 #endif
 
+#ifndef HAVE_ARCH_PCI_SET_DMA_MAX_SEGMENT_SIZE
+int pci_set_dma_max_seg_size(struct pci_dev *dev, unsigned int size)
+{
+        return dma_set_max_seg_size(&dev->dev, size);
+}
+EXPORT_SYMBOL(pci_set_dma_max_seg_size);
+#endif
+
 /**
  * pcix_get_max_mmrbc - get PCI-X maximum designed memory read byte count
  * @dev: PCI device to query
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 7f5dab34d315..f47d596d5ebc 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -933,8 +933,11 @@ void pci_device_add(struct pci_dev *dev, struct pci_bus *bus)
 
         set_dev_node(&dev->dev, pcibus_to_node(bus));
         dev->dev.dma_mask = &dev->dma_mask;
+        dev->dev.dma_parms = &dev->dma_parms;
         dev->dev.coherent_dma_mask = 0xffffffffull;
 
+        pci_set_dma_max_seg_size(dev, 65536);
+
         /* Fix up broken headers */
         pci_fixup_device(pci_fixup_header, dev);