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

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>

1 files changed, 4 insertions, 4 deletions

diff --git a/arch/x86/boot/boot.h b/arch/x86/boot/boot.h
index 9011a88353de..2edb2d53c3a2 100644
--- a/arch/x86/boot/boot.h
+++ b/arch/x86/boot/boot.h
@@ -176,16 +176,16 @@ static inline void wrgs32(u32 v, addr_t addr)
 }
 
 /* Note: these only return true/false, not a signed return value! */
-static inline int memcmp_fs(const void *s1, addr_t s2, size_t len)
+static inline bool memcmp_fs(const void *s1, addr_t s2, size_t len)
 {
-	u8 diff;
+	bool diff;
 	asm volatile("fs; repe; cmpsb; setnz %0"
 		     : "=qm" (diff), "+D" (s1), "+S" (s2), "+c" (len));
 	return diff;
 }
-static inline int memcmp_gs(const void *s1, addr_t s2, size_t len)
+static inline bool memcmp_gs(const void *s1, addr_t s2, size_t len)
 {
-	u8 diff;
+	bool diff;
 	asm volatile("gs; repe; cmpsb; setnz %0"
 		     : "=qm" (diff), "+D" (s1), "+S" (s2), "+c" (len));
 	return diff;