MIPS: cavium-octeon: fix I/O space setup on non-PCI systems

Fix I/O space setup, so that on non-PCI systems using inb()/outb()
won't crash the system. Some drivers may try to probe I/O space and for
that purpose we can just allocate some normal memory initially. Drivers
trying to reserve a region will fail early as we set the size to 0. If
a real I/O space is present, the PCI/PCIe support code will re-adjust
the values accordingly.

Tested with EdgeRouter Lite by enabling CONFIG_SERIO_I8042 that caused
the originally reported crash.

Reported-by: Faidon Liambotis <paravoid@debian.org>
Signed-off-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Acked-by: David Daney <david.daney@cavium.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/5626/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/arch/mips/pci/pci-octeon.c b/arch/mips/pci/pci-octeon.c
index 95c2ea8..59cccd9 100644
--- a/arch/mips/pci/pci-octeon.c
+++ b/arch/mips/pci/pci-octeon.c
@@ -586,15 +586,16 @@
 	else
 		octeon_dma_bar_type = OCTEON_DMA_BAR_TYPE_BIG;
 
-	/* PCI I/O and PCI MEM values */
-	set_io_port_base(OCTEON_PCI_IOSPACE_BASE);
-	ioport_resource.start = 0;
-	ioport_resource.end = OCTEON_PCI_IOSPACE_SIZE - 1;
 	if (!octeon_is_pci_host()) {
 		pr_notice("Not in host mode, PCI Controller not initialized\n");
 		return 0;
 	}
 
+	/* PCI I/O and PCI MEM values */
+	set_io_port_base(OCTEON_PCI_IOSPACE_BASE);
+	ioport_resource.start = 0;
+	ioport_resource.end = OCTEON_PCI_IOSPACE_SIZE - 1;
+
 	pr_notice("%s Octeon big bar support\n",
 		  (octeon_dma_bar_type ==
 		  OCTEON_DMA_BAR_TYPE_BIG) ? "Enabling" : "Disabling");