1 files changed, 162 insertions, 0 deletions
diff --git a/arch/x86/include/asm/local.h b/arch/x86/include/asm/local.h
new file mode 100644
index 000000000..349a47aca
--- /dev/null
+++ b/arch/x86/include/asm/local.h
@@ -0,0 +1,162 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_X86_LOCAL_H
+#define _ASM_X86_LOCAL_H
+
+#include <linux/percpu.h>
+
+#include <linux/atomic.h>
+#include <asm/asm.h>
+
+typedef struct {
+	atomic_long_t a;
+} local_t;
+
+#define LOCAL_INIT(i)	{ ATOMIC_LONG_INIT(i) }
+
+#define local_read(l)	atomic_long_read(&(l)->a)
+#define local_set(l, i)	atomic_long_set(&(l)->a, (i))
+
+static inline void local_inc(local_t *l)
+{
+	asm volatile(_ASM_INC "%0"
+		     : "+m" (l->a.counter));
+}
+
+static inline void local_dec(local_t *l)
+{
+	asm volatile(_ASM_DEC "%0"
+		     : "+m" (l->a.counter));
+}
+
+static inline void local_add(long i, local_t *l)
+{
+	asm volatile(_ASM_ADD "%1,%0"
+		     : "+m" (l->a.counter)
+		     : "ir" (i));
+}
+
+static inline void local_sub(long i, local_t *l)
+{
+	asm volatile(_ASM_SUB "%1,%0"
+		     : "+m" (l->a.counter)
+		     : "ir" (i));
+}
+
+/**
+ * local_sub_and_test - subtract value from variable and test result
+ * @i: integer value to subtract
+ * @l: pointer to type local_t
+ *
+ * Atomically subtracts @i from @l and returns
+ * true if the result is zero, or false for all
+ * other cases.
+ */
+static inline bool local_sub_and_test(long i, local_t *l)
+{
+	return GEN_BINARY_RMWcc(_ASM_SUB, l->a.counter, e, "er", i);
+}
+
+/**
+ * local_dec_and_test - decrement and test
+ * @l: pointer to type local_t
+ *
+ * Atomically decrements @l by 1 and
+ * returns true if the result is 0, or false for all other
+ * cases.
+ */
+static inline bool local_dec_and_test(local_t *l)
+{
+	return GEN_UNARY_RMWcc(_ASM_DEC, l->a.counter, e);
+}
+
+/**
+ * local_inc_and_test - increment and test
+ * @l: pointer to type local_t
+ *
+ * Atomically increments @l by 1
+ * and returns true if the result is zero, or false for all
+ * other cases.
+ */
+static inline bool local_inc_and_test(local_t *l)
+{
+	return GEN_UNARY_RMWcc(_ASM_INC, l->a.counter, e);
+}
+
+/**
+ * local_add_negative - add and test if negative
+ * @i: integer value to add
+ * @l: pointer to type local_t
+ *
+ * Atomically adds @i to @l and returns true
+ * if the result is negative, or false when
+ * result is greater than or equal to zero.
+ */
+static inline bool local_add_negative(long i, local_t *l)
+{
+	return GEN_BINARY_RMWcc(_ASM_ADD, l->a.counter, s, "er", i);
+}
+
+/**
+ * local_add_return - add and return
+ * @i: integer value to add
+ * @l: pointer to type local_t
+ *
+ * Atomically adds @i to @l and returns @i + @l
+ */
+static inline long local_add_return(long i, local_t *l)
+{
+	long __i = i;
+	asm volatile(_ASM_XADD "%0, %1;"
+		     : "+r" (i), "+m" (l->a.counter)
+		     : : "memory");
+	return i + __i;
+}
+
+static inline long local_sub_return(long i, local_t *l)
+{
+	return local_add_return(-i, l);
+}
+
+#define local_inc_return(l)  (local_add_return(1, l))
+#define local_dec_return(l)  (local_sub_return(1, l))
+
+#define local_cmpxchg(l, o, n) \
+	(cmpxchg_local(&((l)->a.counter), (o), (n)))
+/* Always has a lock prefix */
+#define local_xchg(l, n) (xchg(&((l)->a.counter), (n)))
+
+/**
+ * local_add_unless - add unless the number is a given value
+ * @l: pointer of type local_t
+ * @a: the amount to add to l...
+ * @u: ...unless l is equal to u.
+ *
+ * Atomically adds @a to @l, so long as it was not @u.
+ * Returns non-zero if @l was not @u, and zero otherwise.
+ */
+#define local_add_unless(l, a, u)				\
+({								\
+	long c, old;						\
+	c = local_read((l));					\
+	for (;;) {						\
+		if (unlikely(c == (u)))				\
+			break;					\
+		old = local_cmpxchg((l), c, c + (a));		\
+		if (likely(old == c))				\
+			break;					\
+		c = old;					\
+	}							\
+	c != (u);						\
+})
+#define local_inc_not_zero(l) local_add_unless((l), 1, 0)
+
+/* On x86_32, these are no better than the atomic variants.
+ * On x86-64 these are better than the atomic variants on SMP kernels
+ * because they dont use a lock prefix.
+ */
+#define __local_inc(l)		local_inc(l)
+#define __local_dec(l)		local_dec(l)
+#define __local_add(i, l)	local_add((i), (l))
+#define __local_sub(i, l)	local_sub((i), (l))
+
+#endif /* _ASM_X86_LOCAL_H */