1 files changed, 272 insertions, 0 deletions
diff --git a/arch/x86/include/asm/atomic.h b/arch/x86/include/asm/atomic.h
new file mode 100644
index 000000000..5e754e895
--- /dev/null
+++ b/arch/x86/include/asm/atomic.h
@@ -0,0 +1,272 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_X86_ATOMIC_H
+#define _ASM_X86_ATOMIC_H
+
+#include <linux/compiler.h>
+#include <linux/types.h>
+#include <asm/alternative.h>
+#include <asm/cmpxchg.h>
+#include <asm/rmwcc.h>
+#include <asm/barrier.h>
+
+/*
+ * Atomic operations that C can't guarantee us.  Useful for
+ * resource counting etc..
+ */
+
+/**
+ * arch_atomic_read - read atomic variable
+ * @v: pointer of type atomic_t
+ *
+ * Atomically reads the value of @v.
+ */
+static __always_inline int arch_atomic_read(const atomic_t *v)
+{
+	/*
+	 * Note for KASAN: we deliberately don't use READ_ONCE_NOCHECK() here,
+	 * it's non-inlined function that increases binary size and stack usage.
+	 */
+	return __READ_ONCE((v)->counter);
+}
+
+/**
+ * arch_atomic_set - set atomic variable
+ * @v: pointer of type atomic_t
+ * @i: required value
+ *
+ * Atomically sets the value of @v to @i.
+ */
+static __always_inline void arch_atomic_set(atomic_t *v, int i)
+{
+	__WRITE_ONCE(v->counter, i);
+}
+
+/**
+ * arch_atomic_add - add integer to atomic variable
+ * @i: integer value to add
+ * @v: pointer of type atomic_t
+ *
+ * Atomically adds @i to @v.
+ */
+static __always_inline void arch_atomic_add(int i, atomic_t *v)
+{
+	asm volatile(LOCK_PREFIX "addl %1,%0"
+		     : "+m" (v->counter)
+		     : "ir" (i) : "memory");
+}
+
+/**
+ * arch_atomic_sub - subtract integer from atomic variable
+ * @i: integer value to subtract
+ * @v: pointer of type atomic_t
+ *
+ * Atomically subtracts @i from @v.
+ */
+static __always_inline void arch_atomic_sub(int i, atomic_t *v)
+{
+	asm volatile(LOCK_PREFIX "subl %1,%0"
+		     : "+m" (v->counter)
+		     : "ir" (i) : "memory");
+}
+
+/**
+ * arch_atomic_sub_and_test - subtract value from variable and test result
+ * @i: integer value to subtract
+ * @v: pointer of type atomic_t
+ *
+ * Atomically subtracts @i from @v and returns
+ * true if the result is zero, or false for all
+ * other cases.
+ */
+static __always_inline bool arch_atomic_sub_and_test(int i, atomic_t *v)
+{
+	return GEN_BINARY_RMWcc(LOCK_PREFIX "subl", v->counter, e, "er", i);
+}
+#define arch_atomic_sub_and_test arch_atomic_sub_and_test
+
+/**
+ * arch_atomic_inc - increment atomic variable
+ * @v: pointer of type atomic_t
+ *
+ * Atomically increments @v by 1.
+ */
+static __always_inline void arch_atomic_inc(atomic_t *v)
+{
+	asm volatile(LOCK_PREFIX "incl %0"
+		     : "+m" (v->counter) :: "memory");
+}
+#define arch_atomic_inc arch_atomic_inc
+
+/**
+ * arch_atomic_dec - decrement atomic variable
+ * @v: pointer of type atomic_t
+ *
+ * Atomically decrements @v by 1.
+ */
+static __always_inline void arch_atomic_dec(atomic_t *v)
+{
+	asm volatile(LOCK_PREFIX "decl %0"
+		     : "+m" (v->counter) :: "memory");
+}
+#define arch_atomic_dec arch_atomic_dec
+
+/**
+ * arch_atomic_dec_and_test - decrement and test
+ * @v: pointer of type atomic_t
+ *
+ * Atomically decrements @v by 1 and
+ * returns true if the result is 0, or false for all other
+ * cases.
+ */
+static __always_inline bool arch_atomic_dec_and_test(atomic_t *v)
+{
+	return GEN_UNARY_RMWcc(LOCK_PREFIX "decl", v->counter, e);
+}
+#define arch_atomic_dec_and_test arch_atomic_dec_and_test
+
+/**
+ * arch_atomic_inc_and_test - increment and test
+ * @v: pointer of type atomic_t
+ *
+ * Atomically increments @v by 1
+ * and returns true if the result is zero, or false for all
+ * other cases.
+ */
+static __always_inline bool arch_atomic_inc_and_test(atomic_t *v)
+{
+	return GEN_UNARY_RMWcc(LOCK_PREFIX "incl", v->counter, e);
+}
+#define arch_atomic_inc_and_test arch_atomic_inc_and_test
+
+/**
+ * arch_atomic_add_negative - add and test if negative
+ * @i: integer value to add
+ * @v: pointer of type atomic_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 __always_inline bool arch_atomic_add_negative(int i, atomic_t *v)
+{
+	return GEN_BINARY_RMWcc(LOCK_PREFIX "addl", v->counter, s, "er", i);
+}
+#define arch_atomic_add_negative arch_atomic_add_negative
+
+/**
+ * arch_atomic_add_return - add integer and return
+ * @i: integer value to add
+ * @v: pointer of type atomic_t
+ *
+ * Atomically adds @i to @v and returns @i + @v
+ */
+static __always_inline int arch_atomic_add_return(int i, atomic_t *v)
+{
+	return i + xadd(&v->counter, i);
+}
+#define arch_atomic_add_return arch_atomic_add_return
+
+/**
+ * arch_atomic_sub_return - subtract integer and return
+ * @v: pointer of type atomic_t
+ * @i: integer value to subtract
+ *
+ * Atomically subtracts @i from @v and returns @v - @i
+ */
+static __always_inline int arch_atomic_sub_return(int i, atomic_t *v)
+{
+	return arch_atomic_add_return(-i, v);
+}
+#define arch_atomic_sub_return arch_atomic_sub_return
+
+static __always_inline int arch_atomic_fetch_add(int i, atomic_t *v)
+{
+	return xadd(&v->counter, i);
+}
+#define arch_atomic_fetch_add arch_atomic_fetch_add
+
+static __always_inline int arch_atomic_fetch_sub(int i, atomic_t *v)
+{
+	return xadd(&v->counter, -i);
+}
+#define arch_atomic_fetch_sub arch_atomic_fetch_sub
+
+static __always_inline int arch_atomic_cmpxchg(atomic_t *v, int old, int new)
+{
+	return arch_cmpxchg(&v->counter, old, new);
+}
+#define arch_atomic_cmpxchg arch_atomic_cmpxchg
+
+static __always_inline bool arch_atomic_try_cmpxchg(atomic_t *v, int *old, int new)
+{
+	return arch_try_cmpxchg(&v->counter, old, new);
+}
+#define arch_atomic_try_cmpxchg arch_atomic_try_cmpxchg
+
+static __always_inline int arch_atomic_xchg(atomic_t *v, int new)
+{
+	return arch_xchg(&v->counter, new);
+}
+#define arch_atomic_xchg arch_atomic_xchg
+
+static __always_inline void arch_atomic_and(int i, atomic_t *v)
+{
+	asm volatile(LOCK_PREFIX "andl %1,%0"
+			: "+m" (v->counter)
+			: "ir" (i)
+			: "memory");
+}
+
+static __always_inline int arch_atomic_fetch_and(int i, atomic_t *v)
+{
+	int val = arch_atomic_read(v);
+
+	do { } while (!arch_atomic_try_cmpxchg(v, &val, val & i));
+
+	return val;
+}
+#define arch_atomic_fetch_and arch_atomic_fetch_and
+
+static __always_inline void arch_atomic_or(int i, atomic_t *v)
+{
+	asm volatile(LOCK_PREFIX "orl %1,%0"
+			: "+m" (v->counter)
+			: "ir" (i)
+			: "memory");
+}
+
+static __always_inline int arch_atomic_fetch_or(int i, atomic_t *v)
+{
+	int val = arch_atomic_read(v);
+
+	do { } while (!arch_atomic_try_cmpxchg(v, &val, val | i));
+
+	return val;
+}
+#define arch_atomic_fetch_or arch_atomic_fetch_or
+
+static __always_inline void arch_atomic_xor(int i, atomic_t *v)
+{
+	asm volatile(LOCK_PREFIX "xorl %1,%0"
+			: "+m" (v->counter)
+			: "ir" (i)
+			: "memory");
+}
+
+static __always_inline int arch_atomic_fetch_xor(int i, atomic_t *v)
+{
+	int val = arch_atomic_read(v);
+
+	do { } while (!arch_atomic_try_cmpxchg(v, &val, val ^ i));
+
+	return val;
+}
+#define arch_atomic_fetch_xor arch_atomic_fetch_xor
+
+#ifdef CONFIG_X86_32
+# include <asm/atomic64_32.h>
+#else
+# include <asm/atomic64_64.h>
+#endif
+
+#endif /* _ASM_X86_ATOMIC_H */