Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/arch/arm64/include/asm/lse.h b/arch/arm64/include/asm/lse.h
index 8262325..80b3882 100644
--- a/arch/arm64/include/asm/lse.h
+++ b/arch/arm64/include/asm/lse.h
@@ -2,56 +2,47 @@
 #ifndef __ASM_LSE_H
 #define __ASM_LSE_H
 
+#include <asm/atomic_ll_sc.h>
+
 #if defined(CONFIG_AS_LSE) && defined(CONFIG_ARM64_LSE_ATOMICS)
 
 #include <linux/compiler_types.h>
 #include <linux/export.h>
+#include <linux/jump_label.h>
 #include <linux/stringify.h>
 #include <asm/alternative.h>
+#include <asm/atomic_lse.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__ */
-
 __asm__(".arch_extension	lse");
 
-/* 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))
+extern struct static_key_false cpu_hwcap_keys[ARM64_NCAPS];
+extern struct static_key_false arm64_const_caps_ready;
 
-/* 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"
+static inline bool system_uses_lse_atomics(void)
+{
+	return (static_branch_likely(&arm64_const_caps_ready)) &&
+		static_branch_likely(&cpu_hwcap_keys[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, ARM64_HAS_LSE_ATOMICS)
 
-#endif	/* __ASSEMBLER__ */
 #else	/* CONFIG_AS_LSE && CONFIG_ARM64_LSE_ATOMICS */
 
-#ifdef __ASSEMBLER__
+static inline bool system_uses_lse_atomics(void) { return false; }
 
-.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 __lse_ll_sc_body(op, ...)		__ll_sc_##op(__VA_ARGS__)
 
 #define ARM64_LSE_ATOMIC_INSN(llsc, lse)	llsc
 
-#endif	/* __ASSEMBLER__ */
 #endif	/* CONFIG_AS_LSE && CONFIG_ARM64_LSE_ATOMICS */
 #endif	/* __ASM_LSE_H */