[PATCH 5.14 071/334] m68k: Fix asm register constraints for atomic ops

From: Greg Kroah-Hartman
Date: Mon Sep 13 2021 - 10:27:07 EST


From: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>

[ Upstream commit 87d93029fe83e326d5b906e12e95600b157d2c0d ]

Depending on register assignment by the compiler:

{standard input}:3084: Error: operands mismatch -- statement `andl %a1,%d1' ignored
{standard input}:3145: Error: operands mismatch -- statement `orl %a1,%d1' ignored
{standard input}:3195: Error: operands mismatch -- statement `eorl %a1,%d1' ignored

Indeed, the first operand must not be an address register. However, it
can be an immediate value. Fix this by adjusting the register
constraint from "g" (general purpose register) to "di" (data register or
immediate).

Fixes: e39d88ea3ce4a471 ("locking/atomic, arch/m68k: Implement atomic_fetch_{add,sub,and,or,xor}()")
Fixes: d839bae4269aea46 ("locking,arch,m68k: Fold atomic_ops")
Fixes: 1da177e4c3f41524 ("Linux-2.6.12-rc2")
Reported-by: kernel test robot <lkp@xxxxxxxxx>
Reported-by: Arnd Bergmann <arnd@xxxxxxxx>
Reported-by: Alexander Viro <viro@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
Tested-by: Arnd Bergmann <arnd@xxxxxxxx>
Link: https://lore.kernel.org/r/20210809112903.3898660-1-geert@xxxxxxxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
arch/m68k/include/asm/atomic.h | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/m68k/include/asm/atomic.h b/arch/m68k/include/asm/atomic.h
index 8637bf8a2f65..cfba83d230fd 100644
--- a/arch/m68k/include/asm/atomic.h
+++ b/arch/m68k/include/asm/atomic.h
@@ -48,7 +48,7 @@ static inline int arch_atomic_##op##_return(int i, atomic_t *v) \
" casl %2,%1,%0\n" \
" jne 1b" \
: "+m" (*v), "=&d" (t), "=&d" (tmp) \
- : "g" (i), "2" (arch_atomic_read(v))); \
+ : "di" (i), "2" (arch_atomic_read(v))); \
return t; \
}

@@ -63,7 +63,7 @@ static inline int arch_atomic_fetch_##op(int i, atomic_t *v) \
" casl %2,%1,%0\n" \
" jne 1b" \
: "+m" (*v), "=&d" (t), "=&d" (tmp) \
- : "g" (i), "2" (arch_atomic_read(v))); \
+ : "di" (i), "2" (arch_atomic_read(v))); \
return tmp; \
}

--
2.30.2