[PATCH RFC v4 9/9] powerpc/powernv/pci: Enable reassigning the bus numbers

[Sergey Miroshnichenko <s.miroshnichenko@yadro.com>]

When the pci=realloc command line switch is enabled (which should only be
set when working on on top of the skiboot with the "core/pci: Sync VFs and
the changes of bdfns between the firmware and the OS" patch serie applied),
PowerNV will not depend on PCIe topology info from DT anymore.

This makes possible to re-enumerate the fabric, assign the new bus numbers
and switch from the pnv_php module to the standard pciehp driver for PCIe
hotplug functionality.

Signed-off-by: Sergey Miroshnichenko <s.miroshnichenko@yadro.com>
---
 arch/powerpc/kernel/pci_dn.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/arch/powerpc/kernel/pci_dn.c b/arch/powerpc/kernel/pci_dn.c
index b1dc788865b9..b823c4177184 100644
--- a/arch/powerpc/kernel/pci_dn.c
+++ b/arch/powerpc/kernel/pci_dn.c
@@ -601,3 +601,15 @@ static void pci_dev_pdn_setup(struct pci_dev *pdev)
 	pdev->dev.archdata.pci_data = pdn;
 }
 DECLARE_PCI_FIXUP_EARLY(PCI_ANY_ID, PCI_ANY_ID, pci_dev_pdn_setup);
+
+char * __init pcibios_setup(char *str)
+{
+	if (!strncmp(str, "realloc=", 8)) {
+		if (!strncmp(str + 8, "on", 2))
+			pci_add_flags(PCI_REASSIGN_ALL_BUS);
+	} else if (!strncmp(str, "realloc", 7)) {
+		pci_add_flags(PCI_REASSIGN_ALL_BUS);
+	}
+
+	return str;
+}
-- 
2.20.1