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-rw-r--r--arch/cris/include/asm/cmpxchg.h53
1 files changed, 53 insertions, 0 deletions
diff --git a/arch/cris/include/asm/cmpxchg.h b/arch/cris/include/asm/cmpxchg.h
new file mode 100644
index 0000000..b756dac
--- /dev/null
+++ b/arch/cris/include/asm/cmpxchg.h
@@ -0,0 +1,53 @@
+#ifndef __ASM_CRIS_CMPXCHG__
+#define __ASM_CRIS_CMPXCHG__
+
+#include <linux/irqflags.h>
+
+static inline unsigned long __xchg(unsigned long x, volatile void * ptr, int size)
+{
+ /* since Etrax doesn't have any atomic xchg instructions, we need to disable
+ irq's (if enabled) and do it with move.d's */
+ unsigned long flags,temp;
+ local_irq_save(flags); /* save flags, including irq enable bit and shut off irqs */
+ switch (size) {
+ case 1:
+ *((unsigned char *)&temp) = x;
+ x = *(unsigned char *)ptr;
+ *(unsigned char *)ptr = *((unsigned char *)&temp);
+ break;
+ case 2:
+ *((unsigned short *)&temp) = x;
+ x = *(unsigned short *)ptr;
+ *(unsigned short *)ptr = *((unsigned short *)&temp);
+ break;
+ case 4:
+ temp = x;
+ x = *(unsigned long *)ptr;
+ *(unsigned long *)ptr = temp;
+ break;
+ }
+ local_irq_restore(flags); /* restore irq enable bit */
+ return x;
+}
+
+#define xchg(ptr,x) \
+ ((__typeof__(*(ptr)))__xchg((unsigned long)(x),(ptr),sizeof(*(ptr))))
+
+#define tas(ptr) (xchg((ptr),1))
+
+#include <asm-generic/cmpxchg-local.h>
+
+/*
+ * cmpxchg_local and cmpxchg64_local are atomic wrt current CPU. Always make
+ * them available.
+ */
+#define cmpxchg_local(ptr, o, n) \
+ ((__typeof__(*(ptr)))__cmpxchg_local_generic((ptr), (unsigned long)(o),\
+ (unsigned long)(n), sizeof(*(ptr))))
+#define cmpxchg64_local(ptr, o, n) __cmpxchg64_local_generic((ptr), (o), (n))
+
+#ifndef CONFIG_SMP
+#include <asm-generic/cmpxchg.h>
+#endif
+
+#endif /* __ASM_CRIS_CMPXCHG__ */