File-copy from v4.4.100

This is the result of 'cp' from a linux-stable tree with the 'v4.4.100'
tag checked out (commit 26d6298789e695c9f627ce49a7bbd2286405798a) on
git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git

Please refer to that tree for all history prior to this point.

Change-Id: I8a9ee2aea93cd29c52c847d0ce33091a73ae6afe
diff --git a/arch/x86/include/asm/atomic64_32.h b/arch/x86/include/asm/atomic64_32.h
new file mode 100644
index 0000000..a11c30b
--- /dev/null
+++ b/arch/x86/include/asm/atomic64_32.h
@@ -0,0 +1,330 @@
+#ifndef _ASM_X86_ATOMIC64_32_H
+#define _ASM_X86_ATOMIC64_32_H
+
+#include <linux/compiler.h>
+#include <linux/types.h>
+#include <asm/processor.h>
+//#include <asm/cmpxchg.h>
+
+/* An 64bit atomic type */
+
+typedef struct {
+	u64 __aligned(8) counter;
+} atomic64_t;
+
+#define ATOMIC64_INIT(val)	{ (val) }
+
+#define __ATOMIC64_DECL(sym) void atomic64_##sym(atomic64_t *, ...)
+#ifndef ATOMIC64_EXPORT
+#define ATOMIC64_DECL_ONE __ATOMIC64_DECL
+#else
+#define ATOMIC64_DECL_ONE(sym) __ATOMIC64_DECL(sym); \
+	ATOMIC64_EXPORT(atomic64_##sym)
+#endif
+
+#ifdef CONFIG_X86_CMPXCHG64
+#define __alternative_atomic64(f, g, out, in...) \
+	asm volatile("call %P[func]" \
+		     : out : [func] "i" (atomic64_##g##_cx8), ## in)
+
+#define ATOMIC64_DECL(sym) ATOMIC64_DECL_ONE(sym##_cx8)
+#else
+#define __alternative_atomic64(f, g, out, in...) \
+	alternative_call(atomic64_##f##_386, atomic64_##g##_cx8, \
+			 X86_FEATURE_CX8, ASM_OUTPUT2(out), ## in)
+
+#define ATOMIC64_DECL(sym) ATOMIC64_DECL_ONE(sym##_cx8); \
+	ATOMIC64_DECL_ONE(sym##_386)
+
+ATOMIC64_DECL_ONE(add_386);
+ATOMIC64_DECL_ONE(sub_386);
+ATOMIC64_DECL_ONE(inc_386);
+ATOMIC64_DECL_ONE(dec_386);
+#endif
+
+#define alternative_atomic64(f, out, in...) \
+	__alternative_atomic64(f, f, ASM_OUTPUT2(out), ## in)
+
+ATOMIC64_DECL(read);
+ATOMIC64_DECL(set);
+ATOMIC64_DECL(xchg);
+ATOMIC64_DECL(add_return);
+ATOMIC64_DECL(sub_return);
+ATOMIC64_DECL(inc_return);
+ATOMIC64_DECL(dec_return);
+ATOMIC64_DECL(dec_if_positive);
+ATOMIC64_DECL(inc_not_zero);
+ATOMIC64_DECL(add_unless);
+
+#undef ATOMIC64_DECL
+#undef ATOMIC64_DECL_ONE
+#undef __ATOMIC64_DECL
+#undef ATOMIC64_EXPORT
+
+/**
+ * atomic64_cmpxchg - cmpxchg atomic64 variable
+ * @v: pointer to type atomic64_t
+ * @o: expected value
+ * @n: new value
+ *
+ * Atomically sets @v to @n if it was equal to @o and returns
+ * the old value.
+ */
+
+static inline long long atomic64_cmpxchg(atomic64_t *v, long long o, long long n)
+{
+	return cmpxchg64(&v->counter, o, n);
+}
+
+/**
+ * atomic64_xchg - xchg atomic64 variable
+ * @v: pointer to type atomic64_t
+ * @n: value to assign
+ *
+ * Atomically xchgs the value of @v to @n and returns
+ * the old value.
+ */
+static inline long long atomic64_xchg(atomic64_t *v, long long n)
+{
+	long long o;
+	unsigned high = (unsigned)(n >> 32);
+	unsigned low = (unsigned)n;
+	alternative_atomic64(xchg, "=&A" (o),
+			     "S" (v), "b" (low), "c" (high)
+			     : "memory");
+	return o;
+}
+
+/**
+ * atomic64_set - set atomic64 variable
+ * @v: pointer to type atomic64_t
+ * @i: value to assign
+ *
+ * Atomically sets the value of @v to @n.
+ */
+static inline void atomic64_set(atomic64_t *v, long long i)
+{
+	unsigned high = (unsigned)(i >> 32);
+	unsigned low = (unsigned)i;
+	alternative_atomic64(set, /* no output */,
+			     "S" (v), "b" (low), "c" (high)
+			     : "eax", "edx", "memory");
+}
+
+/**
+ * atomic64_read - read atomic64 variable
+ * @v: pointer to type atomic64_t
+ *
+ * Atomically reads the value of @v and returns it.
+ */
+static inline long long atomic64_read(const atomic64_t *v)
+{
+	long long r;
+	alternative_atomic64(read, "=&A" (r), "c" (v) : "memory");
+	return r;
+ }
+
+/**
+ * atomic64_add_return - add and return
+ * @i: integer value to add
+ * @v: pointer to type atomic64_t
+ *
+ * Atomically adds @i to @v and returns @i + *@v
+ */
+static inline long long atomic64_add_return(long long i, atomic64_t *v)
+{
+	alternative_atomic64(add_return,
+			     ASM_OUTPUT2("+A" (i), "+c" (v)),
+			     ASM_NO_INPUT_CLOBBER("memory"));
+	return i;
+}
+
+/*
+ * Other variants with different arithmetic operators:
+ */
+static inline long long atomic64_sub_return(long long i, atomic64_t *v)
+{
+	alternative_atomic64(sub_return,
+			     ASM_OUTPUT2("+A" (i), "+c" (v)),
+			     ASM_NO_INPUT_CLOBBER("memory"));
+	return i;
+}
+
+static inline long long atomic64_inc_return(atomic64_t *v)
+{
+	long long a;
+	alternative_atomic64(inc_return, "=&A" (a),
+			     "S" (v) : "memory", "ecx");
+	return a;
+}
+
+static inline long long atomic64_dec_return(atomic64_t *v)
+{
+	long long a;
+	alternative_atomic64(dec_return, "=&A" (a),
+			     "S" (v) : "memory", "ecx");
+	return a;
+}
+
+/**
+ * atomic64_add - add integer to atomic64 variable
+ * @i: integer value to add
+ * @v: pointer to type atomic64_t
+ *
+ * Atomically adds @i to @v.
+ */
+static inline long long atomic64_add(long long i, atomic64_t *v)
+{
+	__alternative_atomic64(add, add_return,
+			       ASM_OUTPUT2("+A" (i), "+c" (v)),
+			       ASM_NO_INPUT_CLOBBER("memory"));
+	return i;
+}
+
+/**
+ * atomic64_sub - subtract the atomic64 variable
+ * @i: integer value to subtract
+ * @v: pointer to type atomic64_t
+ *
+ * Atomically subtracts @i from @v.
+ */
+static inline long long atomic64_sub(long long i, atomic64_t *v)
+{
+	__alternative_atomic64(sub, sub_return,
+			       ASM_OUTPUT2("+A" (i), "+c" (v)),
+			       ASM_NO_INPUT_CLOBBER("memory"));
+	return i;
+}
+
+/**
+ * atomic64_sub_and_test - subtract value from variable and test result
+ * @i: integer value to subtract
+ * @v: pointer to type atomic64_t
+ *
+ * Atomically subtracts @i from @v and returns
+ * true if the result is zero, or false for all
+ * other cases.
+ */
+static inline int atomic64_sub_and_test(long long i, atomic64_t *v)
+{
+	return atomic64_sub_return(i, v) == 0;
+}
+
+/**
+ * atomic64_inc - increment atomic64 variable
+ * @v: pointer to type atomic64_t
+ *
+ * Atomically increments @v by 1.
+ */
+static inline void atomic64_inc(atomic64_t *v)
+{
+	__alternative_atomic64(inc, inc_return, /* no output */,
+			       "S" (v) : "memory", "eax", "ecx", "edx");
+}
+
+/**
+ * atomic64_dec - decrement atomic64 variable
+ * @v: pointer to type atomic64_t
+ *
+ * Atomically decrements @v by 1.
+ */
+static inline void atomic64_dec(atomic64_t *v)
+{
+	__alternative_atomic64(dec, dec_return, /* no output */,
+			       "S" (v) : "memory", "eax", "ecx", "edx");
+}
+
+/**
+ * atomic64_dec_and_test - decrement and test
+ * @v: pointer to type atomic64_t
+ *
+ * Atomically decrements @v by 1 and
+ * returns true if the result is 0, or false for all other
+ * cases.
+ */
+static inline int atomic64_dec_and_test(atomic64_t *v)
+{
+	return atomic64_dec_return(v) == 0;
+}
+
+/**
+ * atomic64_inc_and_test - increment and test
+ * @v: pointer to type atomic64_t
+ *
+ * Atomically increments @v by 1
+ * and returns true if the result is zero, or false for all
+ * other cases.
+ */
+static inline int atomic64_inc_and_test(atomic64_t *v)
+{
+	return atomic64_inc_return(v) == 0;
+}
+
+/**
+ * atomic64_add_negative - add and test if negative
+ * @i: integer value to add
+ * @v: pointer to type atomic64_t
+ *
+ * Atomically adds @i to @v and returns true
+ * if the result is negative, or false when
+ * result is greater than or equal to zero.
+ */
+static inline int atomic64_add_negative(long long i, atomic64_t *v)
+{
+	return atomic64_add_return(i, v) < 0;
+}
+
+/**
+ * atomic64_add_unless - add unless the number is a given value
+ * @v: pointer of type atomic64_t
+ * @a: the amount to add to v...
+ * @u: ...unless v is equal to u.
+ *
+ * Atomically adds @a to @v, so long as it was not @u.
+ * Returns non-zero if the add was done, zero otherwise.
+ */
+static inline int atomic64_add_unless(atomic64_t *v, long long a, long long u)
+{
+	unsigned low = (unsigned)u;
+	unsigned high = (unsigned)(u >> 32);
+	alternative_atomic64(add_unless,
+			     ASM_OUTPUT2("+A" (a), "+c" (low), "+D" (high)),
+			     "S" (v) : "memory");
+	return (int)a;
+}
+
+
+static inline int atomic64_inc_not_zero(atomic64_t *v)
+{
+	int r;
+	alternative_atomic64(inc_not_zero, "=&a" (r),
+			     "S" (v) : "ecx", "edx", "memory");
+	return r;
+}
+
+static inline long long atomic64_dec_if_positive(atomic64_t *v)
+{
+	long long r;
+	alternative_atomic64(dec_if_positive, "=&A" (r),
+			     "S" (v) : "ecx", "memory");
+	return r;
+}
+
+#undef alternative_atomic64
+#undef __alternative_atomic64
+
+#define ATOMIC64_OP(op, c_op)						\
+static inline void atomic64_##op(long long i, atomic64_t *v)		\
+{									\
+	long long old, c = 0;						\
+	while ((old = atomic64_cmpxchg(v, c, c c_op i)) != c)		\
+		c = old;						\
+}
+
+ATOMIC64_OP(and, &)
+ATOMIC64_OP(or, |)
+ATOMIC64_OP(xor, ^)
+
+#undef ATOMIC64_OP
+
+#endif /* _ASM_X86_ATOMIC64_32_H */