powerpc/pci: Refactor pci_dn

Currently, the PCI config accessors are implemented based on device node.
Unfortunately, SRIOV VFs won't have the corresponding device nodes. pci_dn
will be used in replacement with device node for SRIOV VFs. So we have to
use pci_dn in PCI config accessors.

The patch refactors pci_dn in following aspects to make it ready to be used
in PCI config accessors as we do in subsequent patch:

   * pci_dn is organized as a hierarchy tree.  PCI device's pci_dn is
     put to the child list of pci_dn of its upstream bridge or PHB. VF's
     pci_dn will be put to the child list of pci_dn of PF's bridge.

   * For one particular PCI device (VF or not), its pci_dn can be
     found from pdev->dev.archdata.pci_data, PCI_DN(devnode), or
     parent's list.  The fast path (fetching pci_dn through PCI device
     instance) is populated during early fixup time.

[bhelgaas: changelog]
Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

1 files changed, 6 insertions, 0 deletions

diff --git a/arch/powerpc/include/asm/device.h b/arch/powerpc/include/asm/device.h
index 38faeded7d59..9f1371bab5fc 100644
--- a/arch/powerpc/include/asm/device.h
+++ b/arch/powerpc/include/asm/device.h
@@ -8,6 +8,9 @@
 
 struct dma_map_ops;
 struct device_node;
+#ifdef CONFIG_PPC64
+struct pci_dn;
+#endif
 
 /*
  * Arch extensions to struct device.
@@ -34,6 +37,9 @@ struct dev_archdata {
 #ifdef CONFIG_SWIOTLB
         dma_addr_t              max_direct_dma_addr;
 #endif
+#ifdef CONFIG_PPC64
+        struct pci_dn           *pci_data;
+#endif
 #ifdef CONFIG_EEH
         struct eeh_dev          *edev;
 #endif