[PATCH] g5: Fix iommu vs. pci_device_to_OF_node

The g5 iommu code would fill the "iommu_table" member of whatever
device node was pointed to by pcidev->sysdata during boot. However,
the ppc64 kernel fills that with a pointer to the PHB node which is
later replaced "lazily" with a pointer to the real node when calling
pci_device_to_OF_node(). In this case, we were thus "losign" the
iommu_table pointer. Typical symptom: loss of the SATA when looking
at it's /proc entry.

This fixes it by forcing the update to the final sysdata pointer
when filling up the iommu_table pointers. The "lazy" thing is useless
on pmac anyway.

arch/ppc64/kernel/pmac_iommu.c

@@ -289,8 +289,11 @@ void iommu_setup_pmac(void)
 	 * things simple. Setup all PCI devices to point to this table
 	 */
 	while ((dev = pci_find_device(PCI_ANY_ID, PCI_ANY_ID, dev)) != NULL) {
-		dn = PCI_GET_DN(dev);
-
+		/* We must use pci_device_to_OF_node() to make sure that
+		 * we get the real "final" pointer to the device in the
+		 * pci_dev sysdata and not the temporary PHB one
+		 */
+		struct device_node *dn = pci_device_to_OF_node(dev);
 		if (dn)
 			dn->iommu_table = &iommu_table_pmac;
 	}