powerpc/powernv: Shift VF resource with an offset

On PowerNV platform, resource position in M64 BAR implies the PE# the
resource belongs to. In some cases, adjustment of a resource is necessary
to locate it to a correct position in M64 BAR .

This patch adds pnv_pci_vf_resource_shift() to shift the 'real' PF IOV BAR
address according to an offset.

Note:

    After doing so, there would be a "hole" in the /proc/iomem when offset
    is a positive value. It looks like the device return some mmio back to
    the system, which actually no one could use it.

[bhelgaas: rework loops, rework overlap check, index resource[]
conventionally, remove pci_regs.h include, squashed with next patch]
Signed-off-by: Wei Yang <weiyang@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

arch/powerpc/kernel/pci_dn.c

@@ -217,6 +217,19 @@ void remove_dev_pci_data(struct pci_dev *pdev)
 	struct pci_dn *pdn, *tmp;
 	int i;
 
+	/*
+	 * VF and VF PE are created/released dynamically, so we need to
+	 * bind/unbind them.  Otherwise the VF and VF PE would be mismatched
+	 * when re-enabling SR-IOV.
+	 */
+	if (pdev->is_virtfn) {
+		pdn = pci_get_pdn(pdev);
+#ifdef CONFIG_PPC_POWERNV
+		pdn->pe_number = IODA_INVALID_PE;
+#endif
+		return;
+	}
+
 	/* Only support IOV PF for now */
 	if (!pdev->is_physfn)
 		return;