1 files changed, 57 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/lse.h b/arch/arm64/include/asm/lse.h
new file mode 100644
index 000000000..13536c4da
--- /dev/null
+++ b/arch/arm64/include/asm/lse.h
@@ -0,0 +1,57 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __ASM_LSE_H
+#define __ASM_LSE_H
+
+#if defined(CONFIG_AS_LSE) && defined(CONFIG_ARM64_LSE_ATOMICS)
+
+#define __LSE_PREAMBLE	".arch_extension lse\n"
+
+#include <linux/compiler_types.h>
+#include <linux/export.h>
+#include <linux/stringify.h>
+#include <asm/alternative.h>
+#include <asm/cpucaps.h>
+
+#ifdef __ASSEMBLER__
+
+.arch_extension	lse
+
+.macro alt_lse, llsc, lse
+	alternative_insn "\llsc", "\lse", ARM64_HAS_LSE_ATOMICS
+.endm
+
+#else	/* __ASSEMBLER__ */
+
+/* Move the ll/sc atomics out-of-line */
+#define __LL_SC_INLINE		notrace
+#define __LL_SC_PREFIX(x)	__ll_sc_##x
+#define __LL_SC_EXPORT(x)	EXPORT_SYMBOL(__LL_SC_PREFIX(x))
+
+/* Macro for constructing calls to out-of-line ll/sc atomics */
+#define __LL_SC_CALL(op)	"bl\t" __stringify(__LL_SC_PREFIX(op)) "\n"
+#define __LL_SC_CLOBBERS	"x16", "x17", "x30"
+
+/* In-line patching at runtime */
+#define ARM64_LSE_ATOMIC_INSN(llsc, lse)				\
+	ALTERNATIVE(llsc, __LSE_PREAMBLE lse, ARM64_HAS_LSE_ATOMICS)
+
+#endif	/* __ASSEMBLER__ */
+#else	/* CONFIG_AS_LSE && CONFIG_ARM64_LSE_ATOMICS */
+
+#ifdef __ASSEMBLER__
+
+.macro alt_lse, llsc, lse
+	\llsc
+.endm
+
+#else	/* __ASSEMBLER__ */
+
+#define __LL_SC_INLINE		static inline
+#define __LL_SC_PREFIX(x)	x
+#define __LL_SC_EXPORT(x)
+
+#define ARM64_LSE_ATOMIC_INSN(llsc, lse)	llsc
+
+#endif	/* __ASSEMBLER__ */
+#endif	/* CONFIG_AS_LSE && CONFIG_ARM64_LSE_ATOMICS */
+#endif	/* __ASM_LSE_H */