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Diffstat (limited to 'kernel/arch/mn10300/include/asm/cmpxchg.h')
-rw-r--r--kernel/arch/mn10300/include/asm/cmpxchg.h115
1 files changed, 115 insertions, 0 deletions
diff --git a/kernel/arch/mn10300/include/asm/cmpxchg.h b/kernel/arch/mn10300/include/asm/cmpxchg.h
new file mode 100644
index 000000000..97a4aaf38
--- /dev/null
+++ b/kernel/arch/mn10300/include/asm/cmpxchg.h
@@ -0,0 +1,115 @@
+/* MN10300 Atomic xchg/cmpxchg operations
+ *
+ * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public Licence
+ * as published by the Free Software Foundation; either version
+ * 2 of the Licence, or (at your option) any later version.
+ */
+#ifndef _ASM_CMPXCHG_H
+#define _ASM_CMPXCHG_H
+
+#include <asm/irqflags.h>
+
+#ifdef CONFIG_SMP
+#ifdef CONFIG_MN10300_HAS_ATOMIC_OPS_UNIT
+static inline
+unsigned long __xchg(volatile unsigned long *m, unsigned long val)
+{
+ unsigned long status;
+ unsigned long oldval;
+
+ asm volatile(
+ "1: mov %4,(_AAR,%3) \n"
+ " mov (_ADR,%3),%1 \n"
+ " mov %5,(_ADR,%3) \n"
+ " mov (_ADR,%3),%0 \n" /* flush */
+ " mov (_ASR,%3),%0 \n"
+ " or %0,%0 \n"
+ " bne 1b \n"
+ : "=&r"(status), "=&r"(oldval), "=m"(*m)
+ : "a"(ATOMIC_OPS_BASE_ADDR), "r"(m), "r"(val)
+ : "memory", "cc");
+
+ return oldval;
+}
+
+static inline unsigned long __cmpxchg(volatile unsigned long *m,
+ unsigned long old, unsigned long new)
+{
+ unsigned long status;
+ unsigned long oldval;
+
+ asm volatile(
+ "1: mov %4,(_AAR,%3) \n"
+ " mov (_ADR,%3),%1 \n"
+ " cmp %5,%1 \n"
+ " bne 2f \n"
+ " mov %6,(_ADR,%3) \n"
+ "2: mov (_ADR,%3),%0 \n" /* flush */
+ " mov (_ASR,%3),%0 \n"
+ " or %0,%0 \n"
+ " bne 1b \n"
+ : "=&r"(status), "=&r"(oldval), "=m"(*m)
+ : "a"(ATOMIC_OPS_BASE_ADDR), "r"(m),
+ "r"(old), "r"(new)
+ : "memory", "cc");
+
+ return oldval;
+}
+#else /* CONFIG_MN10300_HAS_ATOMIC_OPS_UNIT */
+#error "No SMP atomic operation support!"
+#endif /* CONFIG_MN10300_HAS_ATOMIC_OPS_UNIT */
+
+#else /* CONFIG_SMP */
+
+/*
+ * Emulate xchg for non-SMP MN10300
+ */
+struct __xchg_dummy { unsigned long a[100]; };
+#define __xg(x) ((struct __xchg_dummy *)(x))
+
+static inline
+unsigned long __xchg(volatile unsigned long *m, unsigned long val)
+{
+ unsigned long oldval;
+ unsigned long flags;
+
+ flags = arch_local_cli_save();
+ oldval = *m;
+ *m = val;
+ arch_local_irq_restore(flags);
+ return oldval;
+}
+
+/*
+ * Emulate cmpxchg for non-SMP MN10300
+ */
+static inline unsigned long __cmpxchg(volatile unsigned long *m,
+ unsigned long old, unsigned long new)
+{
+ unsigned long oldval;
+ unsigned long flags;
+
+ flags = arch_local_cli_save();
+ oldval = *m;
+ if (oldval == old)
+ *m = new;
+ arch_local_irq_restore(flags);
+ return oldval;
+}
+
+#endif /* CONFIG_SMP */
+
+#define xchg(ptr, v) \
+ ((__typeof__(*(ptr))) __xchg((unsigned long *)(ptr), \
+ (unsigned long)(v)))
+
+#define cmpxchg(ptr, o, n) \
+ ((__typeof__(*(ptr))) __cmpxchg((unsigned long *)(ptr), \
+ (unsigned long)(o), \
+ (unsigned long)(n)))
+
+#endif /* _ASM_CMPXCHG_H */