arm64/bug: Add ARCH_WARN_ASM macro for BUG/WARN asm code sharing with Rust

Add new ARCH_WARN_ASM macro for BUG/WARN assembly code sharing with
Rust to avoid the duplication.

No functional changes.

Acked-by: Catalin Marinas <[email protected]>
Signed-off-by: FUJITA Tomonori <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Miguel Ojeda <[email protected]>

Author: fujita

arch/arm64/include/asm/asm-bug.h

@@ -21,16 +21,21 @@
 #endif
 
 #ifdef CONFIG_GENERIC_BUG
-
-#define __BUG_ENTRY(flags) 				\
+#define __BUG_ENTRY_START				\
 		.pushsection __bug_table,"aw";		\
 		.align 2;				\
 	14470:	.long 14471f - .;			\
-_BUGVERBOSE_LOCATION(__FILE__, __LINE__)		\
-		.short flags; 				\
+
+#define __BUG_ENTRY_END					\
 		.align 2;				\
 		.popsection;				\
 	14471:
+
+#define __BUG_ENTRY(flags)				\
+		__BUG_ENTRY_START			\
+_BUGVERBOSE_LOCATION(__FILE__, __LINE__)		\
+		.short flags;				\
+		__BUG_ENTRY_END
 #else
 #define __BUG_ENTRY(flags)
 #endif
@@ -41,4 +46,24 @@ _BUGVERBOSE_LOCATION(__FILE__, __LINE__)		\
 
 #define ASM_BUG()	ASM_BUG_FLAGS(0)
 
+#ifdef CONFIG_DEBUG_BUGVERBOSE
+#define __BUG_LOCATION_STRING(file, line)		\
+		".long " file "- .;"			\
+		".short " line ";"
+#else
+#define __BUG_LOCATION_STRING(file, line)
+#endif
+
+#define __BUG_ENTRY_STRING(file, line, flags)		\
+		__stringify(__BUG_ENTRY_START)		\
+		__BUG_LOCATION_STRING(file, line)	\
+		".short " flags ";"			\
+		__stringify(__BUG_ENTRY_END)
+
+#define ARCH_WARN_ASM(file, line, flags, size)		\
+	__BUG_ENTRY_STRING(file, line, flags)		\
+	__stringify(brk BUG_BRK_IMM)
+
+#define ARCH_WARN_REACHABLE
+
 #endif /* __ASM_ASM_BUG_H */