Update of /cvsroot/linux-vax/kernel-2.5/include/asm-vax
In directory sc8-pr-cvs1:/tmp/cvs-serv5158/include/asm-vax
Modified Files:
system.h
Log Message:
Need a definition of cmpxchg() in 2.5.37
Index: system.h
===================================================================
RCS file: /cvsroot/linux-vax/kernel-2.5/include/asm-vax/system.h,v
retrieving revision 1.9
retrieving revision 1.10
diff -u -r1.9 -r1.10
--- system.h 14 Feb 2003 02:21:02 -0000 1.9
+++ system.h 17 Feb 2003 20:04:17 -0000 1.10
@@ -38,6 +38,24 @@
extern void __switch_to(struct task_struct*, struct task_struct*);
#define switch_to(prev, next, last) __switch_to((prev), (next))
+/*
+ * Atomic compare and exchange. Compare OLD with MEM, if identical,
+ * store NEW in MEM. Return the initial value in MEM. Success is
+ * indicated by comparing RETURN with OLD.
+ */
+
+#define cmpxchg(ptr, old, new) ({ \
+ unsigned long flags; \
+ __typeof__(*(ptr)) cur; \
+ local_irq_save(flags); \
+ cur = *(ptr); \
+ if (cur == (old)) { \
+ *(ptr) = (new); \
+ } \
+ local_irq_restore(flags); \
+ cur; \
+})
+
/* mb is the alpha instruction to cause serialisation of memory
operations. According to a software note in section 5.5.4 of
part I of the alpha arch handbook (p/no ey-l520e-dp) we dont
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