1 files changed, 70 insertions, 0 deletions
diff --git a/arch/x86/include/asm/rmwcc.h b/arch/x86/include/asm/rmwcc.h
new file mode 100644
index 000000000..8a9eba191
--- /dev/null
+++ b/arch/x86/include/asm/rmwcc.h
@@ -0,0 +1,70 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_X86_RMWcc
+#define _ASM_X86_RMWcc
+
+/* This counts to 12. Any more, it will return 13th argument. */
+#define __RMWcc_ARGS(_0, _1, _2, _3, _4, _5, _6, _7, _8, _9, _10, _11, _12, _n, X...) _n
+#define RMWcc_ARGS(X...) __RMWcc_ARGS(, ##X, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0)
+
+#define __RMWcc_CONCAT(a, b) a ## b
+#define RMWcc_CONCAT(a, b) __RMWcc_CONCAT(a, b)
+
+#define __CLOBBERS_MEM(clb...)	"memory", ## clb
+
+#if !defined(__GCC_ASM_FLAG_OUTPUTS__) && defined(CONFIG_CC_HAS_ASM_GOTO)
+
+/* Use asm goto */
+
+#define __GEN_RMWcc(fullop, _var, cc, clobbers, ...)			\
+({									\
+	bool c = false;							\
+	asm_volatile_goto (fullop "; j" #cc " %l[cc_label]"		\
+			: : [var] "m" (_var), ## __VA_ARGS__		\
+			: clobbers : cc_label);				\
+	if (0) {							\
+cc_label:	c = true;						\
+	}								\
+	c;								\
+})
+
+#else /* defined(__GCC_ASM_FLAG_OUTPUTS__) || !defined(CONFIG_CC_HAS_ASM_GOTO) */
+
+/* Use flags output or a set instruction */
+
+#define __GEN_RMWcc(fullop, _var, cc, clobbers, ...)			\
+({									\
+	bool c;								\
+	asm volatile (fullop CC_SET(cc)					\
+			: [var] "+m" (_var), CC_OUT(cc) (c)		\
+			: __VA_ARGS__ : clobbers);			\
+	c;								\
+})
+
+#endif /* defined(__GCC_ASM_FLAG_OUTPUTS__) || !defined(CONFIG_CC_HAS_ASM_GOTO) */
+
+#define GEN_UNARY_RMWcc_4(op, var, cc, arg0)				\
+	__GEN_RMWcc(op " " arg0, var, cc, __CLOBBERS_MEM())
+
+#define GEN_UNARY_RMWcc_3(op, var, cc)					\
+	GEN_UNARY_RMWcc_4(op, var, cc, "%[var]")
+
+#define GEN_UNARY_RMWcc(X...) RMWcc_CONCAT(GEN_UNARY_RMWcc_, RMWcc_ARGS(X))(X)
+
+#define GEN_BINARY_RMWcc_6(op, var, cc, vcon, _val, arg0)		\
+	__GEN_RMWcc(op " %[val], " arg0, var, cc,			\
+		    __CLOBBERS_MEM(), [val] vcon (_val))
+
+#define GEN_BINARY_RMWcc_5(op, var, cc, vcon, val)			\
+	GEN_BINARY_RMWcc_6(op, var, cc, vcon, val, "%[var]")
+
+#define GEN_BINARY_RMWcc(X...) RMWcc_CONCAT(GEN_BINARY_RMWcc_, RMWcc_ARGS(X))(X)
+
+#define GEN_UNARY_SUFFIXED_RMWcc(op, suffix, var, cc, clobbers...)	\
+	__GEN_RMWcc(op " %[var]\n\t" suffix, var, cc,			\
+		    __CLOBBERS_MEM(clobbers))
+
+#define GEN_BINARY_SUFFIXED_RMWcc(op, suffix, var, cc, vcon, _val, clobbers...)\
+	__GEN_RMWcc(op " %[val], %[var]\n\t" suffix, var, cc,		\
+		    __CLOBBERS_MEM(clobbers), [val] vcon (_val))
+
+#endif /* _ASM_X86_RMWcc */