[PATCH AUTOSEL 5.4 088/134] powerpc/fixmap: Use __fix_to_virt() instead of fix_to_virt()

Sasha Levin
2019-12-11T15:14:00Z

From: Christophe Leroy <christophe.leroy@c-s.fr>

[ Upstream commit 77693a5fb57be4606a6024ec8e3076f9499b906b ]

Modify back __set_fixmap() to using __fix_to_virt() instead
of fix_to_virt() otherwise the following happens because it
seems GCC doesn't see idx as a builtin const.

CC mm/early_ioremap.o
In file included from ./include/linux/kernel.h:11:0,
from mm/early_ioremap.c:11:
In function ‘fix_to_virt’,
inlined from ‘__set_fixmap’ at ./arch/powerpc/include/asm/fixmap.h:87:2,
inlined from ‘__early_ioremap’ at mm/early_ioremap.c:156:4:
./include/linux/compiler.h:350:38: error: call to ‘__compiletime_assert_32’ declared with attribute error: BUILD_BUG_ON failed: idx >= __end_of_fixed_addresses
_compiletime_assert(condition, msg, __compiletime_assert_, __LINE__)
^
./include/linux/compiler.h:331:4: note: in definition of macro ‘__compiletime_assert’
prefix ## suffix(); \
^
./include/linux/compiler.h:350:2: note: in expansion of macro ‘_compiletime_assert’
_compiletime_assert(condition, msg, __compiletime_assert_, __LINE__)
^
./include/linux/build_bug.h:39:37: note: in expansion of macro ‘compiletime_assert’
#define BUILD_BUG_ON_MSG(cond, msg) compiletime_assert(!(cond), msg)
^
./include/linux/build_bug.h:50:2: note: in expansion of macro ‘BUILD_BUG_ON_MSG’
BUILD_BUG_ON_MSG(condition, "BUILD_BUG_ON failed: " #condition)
^
./include/asm-generic/fixmap.h:32:2: note: in expansion of macro ‘BUILD_BUG_ON’
BUILD_BUG_ON(idx >= __end_of_fixed_addresses);
^

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Fixes: 4cfac2f9c7f1 ("powerpc/mm: Simplify __set_fixmap()")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/f4984c615f90caa3277775a68849afeea846850d.1568295907.git.christophe.leroy@c-s.fr
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
arch/powerpc/include/asm/fixmap.h | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/include/asm/fixmap.h b/arch/powerpc/include/asm/fixmap.h
index 0cfc365d814ba..722289a1d000e 100644
--- a/arch/powerpc/include/asm/fixmap.h
+++ b/arch/powerpc/include/asm/fixmap.h
@@ -77,7 +77,12 @@ enum fixed_addresses {
static inline void __set_fixmap(enum fixed_addresses idx,
phys_addr_t phys, pgprot_t flags)
{
- map_kernel_page(fix_to_virt(idx), phys, flags);
+ if (__builtin_constant_p(idx))
+ BUILD_BUG_ON(idx >= __end_of_fixed_addresses);
+ else if (WARN_ON(idx >= __end_of_fixed_addresses))
+ return;
+
+ map_kernel_page(__fix_to_virt(idx), phys, flags);
}

#endif /* !__ASSEMBLY__ */
--
2.20.1