1 files changed, 44 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..cbbcdc35c
--- /dev/null
+++ b/arch/arm64/include/asm/lse.h
@@ -0,0 +1,44 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __ASM_LSE_H
+#define __ASM_LSE_H
+
+#include <asm/atomic_ll_sc.h>
+
+#ifdef 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/alternative-macros.h>
+#include <asm/atomic_lse.h>
+#include <asm/cpucaps.h>
+
+static __always_inline bool system_uses_lse_atomics(void)
+{
+	return alternative_has_cap_likely(ARM64_HAS_LSE_ATOMICS);
+}
+
+#define __lse_ll_sc_body(op, ...)					\
+({									\
+	system_uses_lse_atomics() ?					\
+		__lse_##op(__VA_ARGS__) :				\
+		__ll_sc_##op(__VA_ARGS__);				\
+})
+
+/* In-line patching at runtime */
+#define ARM64_LSE_ATOMIC_INSN(llsc, lse)				\
+	ALTERNATIVE(llsc, __LSE_PREAMBLE lse, ARM64_HAS_LSE_ATOMICS)
+
+#else	/* CONFIG_ARM64_LSE_ATOMICS */
+
+static inline bool system_uses_lse_atomics(void) { return false; }
+
+#define __lse_ll_sc_body(op, ...)		__ll_sc_##op(__VA_ARGS__)
+
+#define ARM64_LSE_ATOMIC_INSN(llsc, lse)	llsc
+
+#endif	/* CONFIG_ARM64_LSE_ATOMICS */
+#endif	/* __ASM_LSE_H */