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-rw-r--r--arch/blackfin/include/asm/cmpxchg.h133
1 files changed, 133 insertions, 0 deletions
diff --git a/arch/blackfin/include/asm/cmpxchg.h b/arch/blackfin/include/asm/cmpxchg.h
new file mode 100644
index 0000000..c05868c
--- /dev/null
+++ b/arch/blackfin/include/asm/cmpxchg.h
@@ -0,0 +1,133 @@
+/*
+ * Copyright 2004-2011 Analog Devices Inc.
+ *
+ * Licensed under the GPL-2 or later.
+ */
+
+#ifndef __ARCH_BLACKFIN_CMPXCHG__
+#define __ARCH_BLACKFIN_CMPXCHG__
+
+#ifdef CONFIG_SMP
+
+#include <linux/linkage.h>
+
+asmlinkage unsigned long __raw_xchg_1_asm(volatile void *ptr, unsigned long value);
+asmlinkage unsigned long __raw_xchg_2_asm(volatile void *ptr, unsigned long value);
+asmlinkage unsigned long __raw_xchg_4_asm(volatile void *ptr, unsigned long value);
+asmlinkage unsigned long __raw_cmpxchg_1_asm(volatile void *ptr,
+ unsigned long new, unsigned long old);
+asmlinkage unsigned long __raw_cmpxchg_2_asm(volatile void *ptr,
+ unsigned long new, unsigned long old);
+asmlinkage unsigned long __raw_cmpxchg_4_asm(volatile void *ptr,
+ unsigned long new, unsigned long old);
+
+static inline unsigned long __xchg(unsigned long x, volatile void *ptr,
+ int size)
+{
+ unsigned long tmp;
+
+ switch (size) {
+ case 1:
+ tmp = __raw_xchg_1_asm(ptr, x);
+ break;
+ case 2:
+ tmp = __raw_xchg_2_asm(ptr, x);
+ break;
+ case 4:
+ tmp = __raw_xchg_4_asm(ptr, x);
+ break;
+ }
+
+ return tmp;
+}
+
+/*
+ * 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.
+ */
+static inline unsigned long __cmpxchg(volatile void *ptr, unsigned long old,
+ unsigned long new, int size)
+{
+ unsigned long tmp;
+
+ switch (size) {
+ case 1:
+ tmp = __raw_cmpxchg_1_asm(ptr, new, old);
+ break;
+ case 2:
+ tmp = __raw_cmpxchg_2_asm(ptr, new, old);
+ break;
+ case 4:
+ tmp = __raw_cmpxchg_4_asm(ptr, new, old);
+ break;
+ }
+
+ return tmp;
+}
+#define cmpxchg(ptr, o, n) \
+ ((__typeof__(*(ptr)))__cmpxchg((ptr), (unsigned long)(o), \
+ (unsigned long)(n), sizeof(*(ptr))))
+
+#else /* !CONFIG_SMP */
+
+#include <mach/blackfin.h>
+#include <asm/irqflags.h>
+
+struct __xchg_dummy {
+ unsigned long a[100];
+};
+#define __xg(x) ((volatile struct __xchg_dummy *)(x))
+
+static inline unsigned long __xchg(unsigned long x, volatile void *ptr,
+ int size)
+{
+ unsigned long tmp = 0;
+ unsigned long flags;
+
+ flags = hard_local_irq_save();
+
+ switch (size) {
+ case 1:
+ __asm__ __volatile__
+ ("%0 = b%2 (z);\n\t"
+ "b%2 = %1;\n\t"
+ : "=&d" (tmp) : "d" (x), "m" (*__xg(ptr)) : "memory");
+ break;
+ case 2:
+ __asm__ __volatile__
+ ("%0 = w%2 (z);\n\t"
+ "w%2 = %1;\n\t"
+ : "=&d" (tmp) : "d" (x), "m" (*__xg(ptr)) : "memory");
+ break;
+ case 4:
+ __asm__ __volatile__
+ ("%0 = %2;\n\t"
+ "%2 = %1;\n\t"
+ : "=&d" (tmp) : "d" (x), "m" (*__xg(ptr)) : "memory");
+ break;
+ }
+ hard_local_irq_restore(flags);
+ return tmp;
+}
+
+#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))
+
+#define cmpxchg(ptr, o, n) cmpxchg_local((ptr), (o), (n))
+#define cmpxchg64(ptr, o, n) cmpxchg64_local((ptr), (o), (n))
+
+#endif /* !CONFIG_SMP */
+
+#define xchg(ptr, x) ((__typeof__(*(ptr)))__xchg((unsigned long)(x), (ptr), sizeof(*(ptr))))
+#define tas(ptr) ((void)xchg((ptr), 1))
+
+#endif /* __ARCH_BLACKFIN_CMPXCHG__ */