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>

1 files changed, 28 insertions, 0 deletions

diff --git a/arch/mips/cavium-octeon/setup.c b/arch/mips/cavium-octeon/setup.c
index 48b08eb9d9e4..b212ae12e5ac 100644
--- a/arch/mips/cavium-octeon/setup.c
+++ b/arch/mips/cavium-octeon/setup.c
@@ -8,6 +8,7 @@
  *   written by Ralf Baechle <ralf@linux-mips.org>
  */
 #include <linux/compiler.h>
+#include <linux/vmalloc.h>
 #include <linux/init.h>
 #include <linux/kernel.h>
 #include <linux/console.h>
@@ -1139,3 +1140,30 @@ static int __init edac_devinit(void)
         return err;
 }
 device_initcall(edac_devinit);
+
+static void __initdata *octeon_dummy_iospace;
+
+static int __init octeon_no_pci_init(void)
+{
+        /*
+         * Initially assume there is no PCI. The PCI/PCIe platform code will
+         * later re-initialize these to correct values if they are present.
+         */
+        octeon_dummy_iospace = vzalloc(IO_SPACE_LIMIT);
+        set_io_port_base((unsigned long)octeon_dummy_iospace);
+        ioport_resource.start = MAX_RESOURCE;
+        ioport_resource.end = 0;
+        return 0;
+}
+core_initcall(octeon_no_pci_init);
+
+static int __init octeon_no_pci_release(void)
+{
+        /*
+         * Release the allocated memory if a real IO space is there.
+         */
+        if ((unsigned long)octeon_dummy_iospace != mips_io_port_base)
+                vfree(octeon_dummy_iospace);
+        return 0;
+}
+late_initcall(octeon_no_pci_release);