[tip:locking/core] arch,mips: Convert smp_mb__*()

From: tip-bot for Peter Zijlstra
Date: Fri Apr 18 2014 - 09:12:40 EST


Commit-ID: 91bbefe6b0fcd2968c34a5a566bda870477afc82
Gitweb: http://git.kernel.org/tip/91bbefe6b0fcd2968c34a5a566bda870477afc82
Author: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
AuthorDate: Thu, 13 Mar 2014 19:00:36 +0100
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Fri, 18 Apr 2014 14:20:38 +0200

arch,mips: Convert smp_mb__*()

MIPS is interesting and has hardware variants that reorder over ll/sc
as well as those that do not.

Implement the 2 new barrier functions as per the old barriers.

Signed-off-by: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Acked-by: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx>
Link: http://lkml.kernel.org/n/tip-9ph49jbae3hol9v721sbc2g6@xxxxxxxxxxxxxx
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Maciej W. Rozycki" <macro@xxxxxxxxxxxxxxxx>
Cc: Ralf Baechle <ralf@xxxxxxxxxxxxxx>
Cc: Will Deacon <will.deacon@xxxxxxx>
Cc: linux-kernel@xxxxxxxxxxxxxxx
Cc: linux-mips@xxxxxxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
arch/mips/include/asm/atomic.h | 9 ---------
arch/mips/include/asm/barrier.h | 3 +++
arch/mips/include/asm/bitops.h | 11 ++---------
arch/mips/kernel/irq.c | 4 ++--
4 files changed, 7 insertions(+), 20 deletions(-)

diff --git a/arch/mips/include/asm/atomic.h b/arch/mips/include/asm/atomic.h
index e8eb3d5..37b2bef 100644
--- a/arch/mips/include/asm/atomic.h
+++ b/arch/mips/include/asm/atomic.h
@@ -761,13 +761,4 @@ static __inline__ int atomic64_add_unless(atomic64_t *v, long a, long u)

#endif /* CONFIG_64BIT */

-/*
- * atomic*_return operations are serializing but not the non-*_return
- * versions.
- */
-#define smp_mb__before_atomic_dec() smp_mb__before_llsc()
-#define smp_mb__after_atomic_dec() smp_llsc_mb()
-#define smp_mb__before_atomic_inc() smp_mb__before_llsc()
-#define smp_mb__after_atomic_inc() smp_llsc_mb()
-
#endif /* _ASM_ATOMIC_H */
diff --git a/arch/mips/include/asm/barrier.h b/arch/mips/include/asm/barrier.h
index e1aa4e4..d0101dd 100644
--- a/arch/mips/include/asm/barrier.h
+++ b/arch/mips/include/asm/barrier.h
@@ -195,4 +195,7 @@ do { \
___p1; \
})

+#define smp_mb__before_atomic() smp_mb__before_llsc()
+#define smp_mb__after_atomic() smp_llsc_mb()
+
#endif /* __ASM_BARRIER_H */
diff --git a/arch/mips/include/asm/bitops.h b/arch/mips/include/asm/bitops.h
index 6a65d49..7c8816f 100644
--- a/arch/mips/include/asm/bitops.h
+++ b/arch/mips/include/asm/bitops.h
@@ -38,13 +38,6 @@
#endif

/*
- * clear_bit() doesn't provide any barrier for the compiler.
- */
-#define smp_mb__before_clear_bit() smp_mb__before_llsc()
-#define smp_mb__after_clear_bit() smp_llsc_mb()
-
-
-/*
* These are the "slower" versions of the functions and are in bitops.c.
* These functions call raw_local_irq_{save,restore}().
*/
@@ -120,7 +113,7 @@ static inline void set_bit(unsigned long nr, volatile unsigned long *addr)
*
* clear_bit() is atomic and may not be reordered. However, it does
* not contain a memory barrier, so if it is used for locking purposes,
- * you should call smp_mb__before_clear_bit() and/or smp_mb__after_clear_bit()
+ * you should call smp_mb__before_atomic() and/or smp_mb__after_atomic()
* in order to ensure changes are visible on other processors.
*/
static inline void clear_bit(unsigned long nr, volatile unsigned long *addr)
@@ -175,7 +168,7 @@ static inline void clear_bit(unsigned long nr, volatile unsigned long *addr)
*/
static inline void clear_bit_unlock(unsigned long nr, volatile unsigned long *addr)
{
- smp_mb__before_clear_bit();
+ smp_mb__before_atomic();
clear_bit(nr, addr);
}

diff --git a/arch/mips/kernel/irq.c b/arch/mips/kernel/irq.c
index d1fea7a..1818da4 100644
--- a/arch/mips/kernel/irq.c
+++ b/arch/mips/kernel/irq.c
@@ -62,9 +62,9 @@ void __init alloc_legacy_irqno(void)

void free_irqno(unsigned int irq)
{
- smp_mb__before_clear_bit();
+ smp_mb__before_atomic();
clear_bit(irq, irq_map);
- smp_mb__after_clear_bit();
+ smp_mb__after_atomic();
}

/*
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/