[patch 13/28] Add cmpxchg_local, cmpxchg64 and cmpxchg64_local to ia64

Mathieu Desnoyers
2007-10-31T22:46:22Z

[-- Attachment #1: add-cmpxchg-local-to-ia64.patch --]
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Add the primitives cmpxchg_local, cmpxchg64 and cmpxchg64_local to ia64. They
use cmpxchg_acq as underlying macro, just like the already existing ia64
cmpxchg().

Changelog:

ia64 cmpxchg_local coding style fix
Quoting Keith Owens:

As a matter of coding style, I prefer

#define cmpxchg_local cmpxchg
#define cmpxchg64_local cmpxchg64

Which makes it absolutely clear that they are the same code. With your
patch, humans have to do a string compare of two defines to see if they
are the same.

Note cmpxchg is *not* a performance win vs interrupt disable / enable on IA64.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Acked-by: Christoph Lameter <clameter@sgi.com>
CC: tony.luck@intel.com
CC: Keith Owens <kaos@ocs.com.au>
---
include/asm-ia64/intrinsics.h | 12 +++++++++---
1 file changed, 9 insertions(+), 3 deletions(-)

Index: linux-2.6-lttng/include/asm-ia64/intrinsics.h
===================================================================
--- linux-2.6-lttng.orig/include/asm-ia64/intrinsics.h 2007-10-31 18:06:31.000000000 -0400
+++ linux-2.6-lttng/include/asm-ia64/intrinsics.h 2007-10-31 18:09:18.000000000 -0400
@@ -153,11 +153,17 @@ extern long ia64_cmpxchg_called_with_bad
(__typeof__(old)) _r_; \
})

-#define cmpxchg_acq(ptr,o,n) ia64_cmpxchg(acq, (ptr), (o), (n), sizeof(*(ptr)))
-#define cmpxchg_rel(ptr,o,n) ia64_cmpxchg(rel, (ptr), (o), (n), sizeof(*(ptr)))
+#define cmpxchg_acq(ptr, o, n) \
+ ia64_cmpxchg(acq, (ptr), (o), (n), sizeof(*(ptr)))
+#define cmpxchg_rel(ptr, o, n) \
+ ia64_cmpxchg(rel, (ptr), (o), (n), sizeof(*(ptr)))

/* for compatibility with other platforms: */
-#define cmpxchg(ptr,o,n) cmpxchg_acq(ptr,o,n)
+#define cmpxchg(ptr, o, n) cmpxchg_acq((ptr), (o), (n))
+#define cmpxchg64(ptr, o, n) cmpxchg_acq((ptr), (o), (n))
+
+#define cmpxchg_local cmpxchg
+#define cmpxchg64_local cmpxchg64

#ifdef CONFIG_IA64_DEBUG_CMPXCHG
# define CMPXCHG_BUGCHECK_DECL int _cmpxchg_bugcheck_count = 128;