[PATCH v5 3/4] ARM: mm: fix build error in fix_to_virt with CONFIG_CC_OPTIMIZE_FOR_DEBUGGING

changbin.du
2018-06-05T08:24:45Z

From: Changbin Du <changbin.du@intel.com>

With '-Og' optimization level, GCC would not optimize a count for a loop
as a constant value. But BUILD_BUG_ON() only accept compile-time constant
values. Let's use __fix_to_virt() to avoid the error.

arch/arm/mm/mmu.o: In function `fix_to_virt':
/home/changbin/work/linux/./include/asm-generic/fixmap.h:31: undefined reference to `__compiletime_assert_31'
Makefile:1051: recipe for target 'vmlinux' failed
make: *** [vmlinux] Error 1

Signed-off-by: Changbin Du <changbin.du@intel.com>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
v2: use __fix_to_virt() to fix the issue.
---
arch/arm/mm/mmu.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c
index e46a6a4..c08d74e 100644
--- a/arch/arm/mm/mmu.c
+++ b/arch/arm/mm/mmu.c
@@ -1599,7 +1599,7 @@ static void __init early_fixmap_shutdown(void)
pte_t *pte;
struct map_desc map;

- map.virtual = fix_to_virt(i);
+ map.virtual = __fix_to_virt(i);
pte = pte_offset_early_fixmap(pmd_off_k(map.virtual), map.virtual);

/* Only i/o device mappings are supported ATM */
--
2.7.4