[PATCH] MIPS: remove const from mips_io_port_base

[Hauke Mehrtens <hauke@hauke-m.de>]

This variable is changed by some platform init code. When LTO is used
gcc assumes that the variable never changes and inlines the constant
instead of checking this variable which is wrong.

This fixes a runtime boot problem when LTO is activated.

Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
---
 arch/mips/include/asm/io.h | 2 +-
 arch/mips/kernel/setup.c   | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/mips/include/asm/io.h b/arch/mips/include/asm/io.h
index a7d0b836f2f7..f28f8cd44dd3 100644
--- a/arch/mips/include/asm/io.h
+++ b/arch/mips/include/asm/io.h
@@ -60,7 +60,7 @@
  * instruction, so the lower 16 bits must be zero.  Should be true on
  * on any sane architecture; generic code does not use this assumption.
  */
-extern const unsigned long mips_io_port_base;
+extern unsigned long mips_io_port_base;
 
 /*
  * Gcc will generate code to load the value of mips_io_port_base after each
diff --git a/arch/mips/kernel/setup.c b/arch/mips/kernel/setup.c
index 2c96c0c68116..153460c531a9 100644
--- a/arch/mips/kernel/setup.c
+++ b/arch/mips/kernel/setup.c
@@ -75,7 +75,7 @@ static char __initdata builtin_cmdline[COMMAND_LINE_SIZE] = CONFIG_CMDLINE;
  * mips_io_port_base is the begin of the address space to which x86 style
  * I/O ports are mapped.
  */
-const unsigned long mips_io_port_base = -1;
+unsigned long mips_io_port_base = -1;
 EXPORT_SYMBOL(mips_io_port_base);
 
 static struct resource code_resource = { .name = "Kernel code", };
-- 
2.11.0