[PATCH 1/6] x86: use macro instead of "0" for setting TICKET_SLOWPATH_FLAG

Juergen Gross
Thu, 30 Apr 2015 10:53:58 -0000

For paravirtualized spinlocks setting the "slowpath" flag in
__ticket_enter_slowpath() is done via setting bit "0" in
lock->tickets.head instead of using a macro.

Change this by defining an appropriate macro.

Signed-off-by: Juergen Gross <jgross at suse.com>
---
 arch/x86/include/asm/spinlock.h       | 3 ++-
 arch/x86/include/asm/spinlock_types.h | 3 ++-
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/arch/x86/include/asm/spinlock.h b/arch/x86/include/asm/spinlock.h
index cf87de3..8ceec8d 100644
--- a/arch/x86/include/asm/spinlock.h
+++ b/arch/x86/include/asm/spinlock.h
@@ -46,7 +46,8 @@ static __always_inline bool static_key_false(struct static_key
*key);

 static inline void __ticket_enter_slowpath(arch_spinlock_t *lock)
 {
-	set_bit(0, (volatile unsigned long *)&lock->tickets.head);
+	set_bit(TICKET_SLOWPATH_BIT,
+		(volatile unsigned long *)&lock->tickets.head);
 }

 #else  /* !CONFIG_PARAVIRT_SPINLOCKS */
diff --git a/arch/x86/include/asm/spinlock_types.h
b/arch/x86/include/asm/spinlock_types.h
index 5f9d757..579409a 100644
--- a/arch/x86/include/asm/spinlock_types.h
+++ b/arch/x86/include/asm/spinlock_types.h
@@ -4,8 +4,9 @@
 #include <linux/types.h>

 #ifdef CONFIG_PARAVIRT_SPINLOCKS
+#define TICKET_SLOWPATH_BIT	0
 #define __TICKET_LOCK_INC	2
-#define TICKET_SLOWPATH_FLAG	((__ticket_t)1)
+#define TICKET_SLOWPATH_FLAG	((__ticket_t)(1 << TICKET_SLOWPATH_BIT))
 #else
 #define __TICKET_LOCK_INC	1
 #define TICKET_SLOWPATH_FLAG	((__ticket_t)0)
--
2.1.4