Commit-ID: 31a8394e069e47dc47f4c29e4213aa943342f19f
Gitweb: http://git.kernel.org/tip/31a8394e069e47dc47f4c29e4213aa943342f19f
Author: Jeremy Fitzhardinge <jeremy@xxxxxxxx>
AuthorDate: Fri, 30 Sep 2011 12:14:10 -0700
Committer: Jeremy Fitzhardinge <jeremy@xxxxxxxx>
CommitDate: Fri, 25 Nov 2011 10:43:12 -0800
x86: consolidate xchg and xadd macros
They both have a basic "put new value in location, return old value"
pattern, so they can use the same macro easily.
Signed-off-by: Jeremy Fitzhardinge <jeremy@xxxxxxxx>
---
arch/x86/include/asm/cmpxchg.h | 114 +++++++++++++---------------------------
1 files changed, 36 insertions(+), 78 deletions(-)
diff --git a/arch/x86/include/asm/cmpxchg.h b/arch/x86/include/asm/cmpxchg.h
index 49eade1..5488e10 100644
--- a/arch/x86/include/asm/cmpxchg.h
+++ b/arch/x86/include/asm/cmpxchg.h
@@ -33,60 +33,47 @@ extern void __add_wrong_size(void)
#define __X86_CASE_Q -1 /* sizeof will never return -1 */
#endif
+/*
+ * An exchange-type operation, which takes a value and a pointer, and
+ * returns a the old value.
+ */
+#define __xchg_op(ptr, arg, op, lock) \
+ ({ \
+ __typeof__ (*(ptr)) __ret = (arg); \
+ switch (sizeof(*(ptr))) { \
+ case __X86_CASE_B: \
+ asm volatile (lock #op "b %b0, %1\n" \
+ : "+r" (__ret), "+m" (*(ptr)) \
+ : : "memory", "cc"); \
+ break; \
+ case __X86_CASE_W: \
+ asm volatile (lock #op "w %w0, %1\n" \
+ : "+r" (__ret), "+m" (*(ptr)) \
+ : : "memory", "cc"); \
+ break; \
+ case __X86_CASE_L: \
+ asm volatile (lock #op "l %0, %1\n" \
+ : "+r" (__ret), "+m" (*(ptr)) \
+ : : "memory", "cc"); \
+ break; \
+ case __X86_CASE_Q: \
+ asm volatile (lock #op "q %q0, %1\n" \
+ : "+r" (__ret), "+m" (*(ptr)) \
+ : : "memory", "cc"); \
+ break; \
+ default: \
+ __ ## op ## _wrong_size(); \
+ } \
+ __ret; \
+ })
+
/*
* Note: no "lock" prefix even on SMP: xchg always implies lock anyway.
* Since this is generally used to protect other memory information, we
* use "asm volatile" and "memory" clobbers to prevent gcc from moving
* information around.
*/
-#define __xchg(x, ptr, size) \
-({ \
- __typeof(*(ptr)) __x = (x); \
- switch (size) { \
- case __X86_CASE_B: \
- { \
- volatile u8 *__ptr = (volatile u8 *)(ptr); \
- asm volatile("xchgb %0,%1" \
- : "=q" (__x), "+m" (*__ptr) \
- : "0" (__x) \
- : "memory"); \
- break; \
- } \
- case __X86_CASE_W: \
- { \
- volatile u16 *__ptr = (volatile u16 *)(ptr); \
- asm volatile("xchgw %0,%1" \
- : "=r" (__x), "+m" (*__ptr) \
- : "0" (__x) \
- : "memory"); \
- break; \
- } \
- case __X86_CASE_L: \
- { \
- volatile u32 *__ptr = (volatile u32 *)(ptr); \
- asm volatile("xchgl %0,%1" \
- : "=r" (__x), "+m" (*__ptr) \
- : "0" (__x) \
- : "memory"); \
- break; \
- } \
- case __X86_CASE_Q: \
- { \
- volatile u64 *__ptr = (volatile u64 *)(ptr); \
- asm volatile("xchgq %0,%1" \
- : "=r" (__x), "+m" (*__ptr) \
- : "0" (__x) \
- : "memory"); \
- break; \
- } \
- default: \
- __xchg_wrong_size(); \
- } \
- __x; \
-})
-
-#define xchg(ptr, v) \
- __xchg((v), (ptr), sizeof(*ptr))
+#define xchg(ptr, v) __xchg_op((ptr), (v), xchg, "")
/*
* Atomic compare and exchange. Compare OLD with MEM, if identical,
@@ -167,36 +154,6 @@ extern void __add_wrong_size(void)
__cmpxchg_local((ptr), (old), (new), sizeof(*ptr))
#endif
-#define __xadd(ptr, inc, lock) \
- ({ \
- __typeof__ (*(ptr)) __ret = (inc); \
- switch (sizeof(*(ptr))) { \
- case __X86_CASE_B: \
- asm volatile (lock "xaddb %b0, %1\n" \
- : "+r" (__ret), "+m" (*(ptr)) \
- : : "memory", "cc"); \
- break; \
- case __X86_CASE_W: \
- asm volatile (lock "xaddw %w0, %1\n" \
- : "+r" (__ret), "+m" (*(ptr)) \
- : : "memory", "cc"); \
- break; \
- case __X86_CASE_L: \
- asm volatile (lock "xaddl %0, %1\n" \
- : "+r" (__ret), "+m" (*(ptr)) \
- : : "memory", "cc"); \
- break; \
- case __X86_CASE_Q: \
- asm volatile (lock "xaddq %q0, %1\n" \
- : "+r" (__ret), "+m" (*(ptr)) \
- : : "memory", "cc"); \
- break; \
- default: \
- __xadd_wrong_size(); \
- } \
- __ret; \
- })
-
/*
* xadd() adds "inc" to "*ptr" and atomically returns the previous
* value of "*ptr".
@@ -205,6 +162,7 @@ extern void __add_wrong_size(void)
* xadd_sync() is always locked
* xadd_local() is never locked
*/
+#define __xadd(ptr, inc, lock) __xchg_op((ptr), (inc), xadd, lock)
#define xadd(ptr, inc) __xadd((ptr), (inc), LOCK_PREFIX)
#define xadd_sync(ptr, inc) __xadd((ptr), (inc), "lock; ")
#define xadd_local(ptr, inc) __xadd((ptr), (inc), "")
--
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