[tip:locking/arch] locking,arch,mn10300: Fold atomic_ops

From: tip-bot for Peter Zijlstra
Date: Thu Aug 14 2014 - 13:22:42 EST


Commit-ID: e69a0ef76627005e3e83d0e086e6bb1d247bb65b
Gitweb: http://git.kernel.org/tip/e69a0ef76627005e3e83d0e086e6bb1d247bb65b
Author: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
AuthorDate: Wed, 26 Mar 2014 17:59:04 +0100
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Thu, 14 Aug 2014 12:48:10 +0200

locking,arch,mn10300: Fold atomic_ops

Many of the atomic op implementations are the same except for one
instruction; fold the lot into a few CPP macros and reduce LoC.

This also prepares for easy addition of new ops.

Signed-off-by: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: David Howells <dhowells@xxxxxxxxxx>
Cc: Koichi Yasutake <yasutake.koichi@xxxxxxxxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx>
Cc: linux-am33-list@xxxxxxxxxx
Link: http://lkml.kernel.org/r/20140508135852.605324173@xxxxxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
arch/mn10300/include/asm/atomic.h | 125 +++++++++++++-------------------------
1 file changed, 42 insertions(+), 83 deletions(-)

diff --git a/arch/mn10300/include/asm/atomic.h b/arch/mn10300/include/asm/atomic.h
index cadeb1e..5be655e 100644
--- a/arch/mn10300/include/asm/atomic.h
+++ b/arch/mn10300/include/asm/atomic.h
@@ -33,7 +33,6 @@
* @v: pointer of type atomic_t
*
* Atomically reads the value of @v. Note that the guaranteed
- * useful range of an atomic_t is only 24 bits.
*/
#define atomic_read(v) (ACCESS_ONCE((v)->counter))

@@ -43,102 +42,62 @@
* @i: required value
*
* Atomically sets the value of @v to @i. Note that the guaranteed
- * useful range of an atomic_t is only 24 bits.
*/
#define atomic_set(v, i) (((v)->counter) = (i))

-/**
- * atomic_add_return - add integer to atomic variable
- * @i: integer value to add
- * @v: pointer of type atomic_t
- *
- * Atomically adds @i to @v and returns the result
- * Note that the guaranteed useful range of an atomic_t is only 24 bits.
- */
-static inline int atomic_add_return(int i, atomic_t *v)
-{
- int retval;
-#ifdef CONFIG_SMP
- int status;
-
- asm volatile(
- "1: mov %4,(_AAR,%3) \n"
- " mov (_ADR,%3),%1 \n"
- " add %5,%1 \n"
- " mov %1,(_ADR,%3) \n"
- " mov (_ADR,%3),%0 \n" /* flush */
- " mov (_ASR,%3),%0 \n"
- " or %0,%0 \n"
- " bne 1b \n"
- : "=&r"(status), "=&r"(retval), "=m"(v->counter)
- : "a"(ATOMIC_OPS_BASE_ADDR), "r"(&v->counter), "r"(i)
- : "memory", "cc");
-
-#else
- unsigned long flags;
+#define ATOMIC_OP(op) \
+static inline void atomic_##op(int i, atomic_t *v) \
+{ \
+ int retval, status; \
+ \
+ asm volatile( \
+ "1: mov %4,(_AAR,%3) \n" \
+ " mov (_ADR,%3),%1 \n" \
+ " " #op " %5,%1 \n" \
+ " mov %1,(_ADR,%3) \n" \
+ " mov (_ADR,%3),%0 \n" /* flush */ \
+ " mov (_ASR,%3),%0 \n" \
+ " or %0,%0 \n" \
+ " bne 1b \n" \
+ : "=&r"(status), "=&r"(retval), "=m"(v->counter) \
+ : "a"(ATOMIC_OPS_BASE_ADDR), "r"(&v->counter), "r"(i) \
+ : "memory", "cc"); \
+}

- flags = arch_local_cli_save();
- retval = v->counter;
- retval += i;
- v->counter = retval;
- arch_local_irq_restore(flags);
-#endif
- return retval;
+#define ATOMIC_OP_RETURN(op) \
+static inline int atomic_##op##_return(int i, atomic_t *v) \
+{ \
+ int retval, status; \
+ \
+ asm volatile( \
+ "1: mov %4,(_AAR,%3) \n" \
+ " mov (_ADR,%3),%1 \n" \
+ " " #op " %5,%1 \n" \
+ " mov %1,(_ADR,%3) \n" \
+ " mov (_ADR,%3),%0 \n" /* flush */ \
+ " mov (_ASR,%3),%0 \n" \
+ " or %0,%0 \n" \
+ " bne 1b \n" \
+ : "=&r"(status), "=&r"(retval), "=m"(v->counter) \
+ : "a"(ATOMIC_OPS_BASE_ADDR), "r"(&v->counter), "r"(i) \
+ : "memory", "cc"); \
+ return retval; \
}

-/**
- * atomic_sub_return - subtract integer from atomic variable
- * @i: integer value to subtract
- * @v: pointer of type atomic_t
- *
- * Atomically subtracts @i from @v and returns the result
- * Note that the guaranteed useful range of an atomic_t is only 24 bits.
- */
-static inline int atomic_sub_return(int i, atomic_t *v)
-{
- int retval;
-#ifdef CONFIG_SMP
- int status;
+#define ATOMIC_OPS(op) ATOMIC_OP(op) ATOMIC_OP_RETURN(op)

- asm volatile(
- "1: mov %4,(_AAR,%3) \n"
- " mov (_ADR,%3),%1 \n"
- " sub %5,%1 \n"
- " mov %1,(_ADR,%3) \n"
- " mov (_ADR,%3),%0 \n" /* flush */
- " mov (_ASR,%3),%0 \n"
- " or %0,%0 \n"
- " bne 1b \n"
- : "=&r"(status), "=&r"(retval), "=m"(v->counter)
- : "a"(ATOMIC_OPS_BASE_ADDR), "r"(&v->counter), "r"(i)
- : "memory", "cc");
+ATOMIC_OPS(add)
+ATOMIC_OPS(sub)

-#else
- unsigned long flags;
- flags = arch_local_cli_save();
- retval = v->counter;
- retval -= i;
- v->counter = retval;
- arch_local_irq_restore(flags);
-#endif
- return retval;
-}
+#undef ATOMIC_OPS
+#undef ATOMIC_OP_RETURN
+#undef ATOMIC_OP

static inline int atomic_add_negative(int i, atomic_t *v)
{
return atomic_add_return(i, v) < 0;
}

-static inline void atomic_add(int i, atomic_t *v)
-{
- atomic_add_return(i, v);
-}
-
-static inline void atomic_sub(int i, atomic_t *v)
-{
- atomic_sub_return(i, v);
-}
-
static inline void atomic_inc(atomic_t *v)
{
atomic_add_return(1, v);
--
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