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x86, asm: use bool for bitops and other assembly outputs

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The gcc people have confirmed that using "bool" when combined with
inline assembly always is treated as a byte-sized operand that can be
assumed to be 0 or 1, which is exactly what the SET instruction
emits.  Change the output types and intermediate variables of as many
operations as practical to "bool".

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Link: http://lkml.kernel.org/r/1465414726-197858-3-git-send-email-hpa@linux.intel.com
Reviewed-by: Andy Lutomirski <luto@kernel.org>
Reviewed-by: Borislav Petkov <bp@suse.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
This commit is contained in:
H. Peter Anvin
2016-06-08 12:38:38 -07:00
committed by H. Peter Anvin
parent 2823d4da5d
commit 117780eef7
13 changed files with 69 additions and 66 deletions
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17
arch/x86/include/asm/rwsem.h
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@@ -77,7 +77,7 @@ static inline void __down_read(struct rw_semaphore *sem)
/*
* trylock for reading -- returns 1 if successful, 0 if contention
*/
static inline int __down_read_trylock(struct rw_semaphore *sem)
static inline bool __down_read_trylock(struct rw_semaphore *sem)
{
long result, tmp;
asm volatile("# beginning __down_read_trylock\n\t"
@@ -93,7 +93,7 @@ static inline int __down_read_trylock(struct rw_semaphore *sem)
: "+m" (sem->count), "=&a" (result), "=&r" (tmp)
: "i" (RWSEM_ACTIVE_READ_BIAS)
: "memory", "cc");
return result >= 0 ? 1 : 0;
return result >= 0;
}
/*
@@ -134,9 +134,10 @@ static inline int __down_write_killable(struct rw_semaphore *sem)
/*
* trylock for writing -- returns 1 if successful, 0 if contention
*/
static inline int __down_write_trylock(struct rw_semaphore *sem)
static inline bool __down_write_trylock(struct rw_semaphore *sem)
{
long result, tmp;
bool result;
long tmp0, tmp1;
asm volatile("# beginning __down_write_trylock\n\t"
" mov %0,%1\n\t"
"1:\n\t"
@@ -144,14 +145,14 @@ static inline int __down_write_trylock(struct rw_semaphore *sem)
/* was the active mask 0 before? */
" jnz 2f\n\t"
" mov %1,%2\n\t"
" add %3,%2\n\t"
" add %4,%2\n\t"
LOCK_PREFIX " cmpxchg %2,%0\n\t"
" jnz 1b\n\t"
"2:\n\t"
" sete %b1\n\t"
" movzbl %b1, %k1\n\t"
" sete %3\n\t"
"# ending __down_write_trylock\n\t"
: "+m" (sem->count), "=&a" (result), "=&r" (tmp)
: "+m" (sem->count), "=&a" (tmp0), "=&r" (tmp1),
"=qm" (result)
: "er" (RWSEM_ACTIVE_WRITE_BIAS)
: "memory", "cc");
return result;