PCI: Add pcibios_iov_resource_alignment() interface

Per the SR-IOV spec r1.1, sec 3.3.14, the required alignment of a PF's IOV
BAR is the size of an individual VF BAR, and the size consumed is the
individual VF BAR size times NumVFs.

The PowerNV platform has additional alignment requirements to help support
its Partitionable Endpoint device isolation feature (see
Documentation/powerpc/pci_iov_resource_on_powernv.txt).

Add a pcibios_iov_resource_alignment() interface to allow platforms to
request additional alignment.

[bhelgaas: changelog, adapt to reworked pci_sriov_resource_alignment(),
drop "align" parameter]
Signed-off-by: Wei Yang <weiyang@linux.vnet.ibm.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

1 files changed, 7 insertions, 1 deletions

diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c
index 64c46925c62d..ee0ebff103a4 100644
--- a/drivers/pci/iov.c
+++ b/drivers/pci/iov.c
@@ -569,6 +569,12 @@ int pci_iov_resource_bar(struct pci_dev *dev, int resno)
                 4 * (resno - PCI_IOV_RESOURCES);
 }
 
+resource_size_t __weak pcibios_iov_resource_alignment(struct pci_dev *dev,
+                                                      int resno)
+{
+        return pci_iov_resource_size(dev, resno);
+}
+
 /**
  * pci_sriov_resource_alignment - get resource alignment for VF BAR
  * @dev: the PCI device
@@ -581,7 +587,7 @@ int pci_iov_resource_bar(struct pci_dev *dev, int resno)
  */
 resource_size_t pci_sriov_resource_alignment(struct pci_dev *dev, int resno)
 {
-        return pci_iov_resource_size(dev, resno);
+        return pcibios_iov_resource_alignment(dev, resno);
 }
 
 /**