linux/include/asm-powerpc/bug.h

#ifndef _ASM_POWERPC_BUG_H
#define _ASM_POWERPC_BUG_H

/*
 * Define an illegal instr to trap on the bug.
 * We don't use 0 because that marks the end of a function
 * in the ELF ABI.  That's "Boo Boo" in case you wonder...
 */
#define BUG_OPCODE .long 0x00b00b00  /* For asm */
#define BUG_ILLEGAL_INSTR "0x00b00b00" /* For BUG macro */

#ifndef __ASSEMBLY__

#ifdef __powerpc64__
#define BUG_TABLE_ENTRY(label, line, file, func) \
	".llong " #label "\n .long " #line "\n .llong " #file ", " #func "\n"
#define TRAP_OP(ra, rb) "1: tdnei " #ra ", " #rb "\n"
#define DATA_TYPE long long
#else 
#define BUG_TABLE_ENTRY(label, line, file, func) \
	".long " #label ", " #line ", " #file ", " #func "\n"
#define TRAP_OP(ra, rb) "1: twnei " #ra ", " #rb "\n"
#define DATA_TYPE int
#endif /* __powerpc64__ */

struct bug_entry {
	unsigned long	bug_addr;
	int		line;
	const char	*file;
	const char	*function;
};

struct bug_entry *find_bug(unsigned long bugaddr);

/*
 * If this bit is set in the line number it means that the trap
 * is for WARN_ON rather than BUG or BUG_ON.
 */
#define BUG_WARNING_TRAP	0x1000000

#ifdef CONFIG_BUG

#define BUG() do {							 \
	__asm__ __volatile__(						 \
		"1:	twi 31,0,0\n"					 \
		".section __bug_table,\"a\"\n\t"			 \
		BUG_TABLE_ENTRY(1b,%0,%1,%2)				 \
		".previous"						 \
		: : "i" (__LINE__), "i" (__FILE__), "i" (__FUNCTION__)); \
} while (0)

#define BUG_ON(x) do {						\
	__asm__ __volatile__(					\
		TRAP_OP(%0,0)					\
		".section __bug_table,\"a\"\n\t"		\
		BUG_TABLE_ENTRY(1b,%1,%2,%3)			\
		".previous"					\
		: : "r" ((DATA_TYPE)(x)), "i" (__LINE__),	\
		    "i" (__FILE__), "i" (__FUNCTION__));	\
} while (0)

#define WARN_ON(x) do {						\
	__asm__ __volatile__(					\
		TRAP_OP(%0,0)					\
		".section __bug_table,\"a\"\n\t"		\
		BUG_TABLE_ENTRY(1b,%1,%2,%3)			\
		".previous"					\
		: : "r" ((DATA_TYPE)(x)),			\
		    "i" (__LINE__ + BUG_WARNING_TRAP),		\
		    "i" (__FILE__), "i" (__FUNCTION__));	\
} while (0)

#define HAVE_ARCH_BUG
#define HAVE_ARCH_BUG_ON
#define HAVE_ARCH_WARN_ON
#endif /* CONFIG_BUG */
#endif /* __ASSEMBLY __ */

#include <asm-generic/bug.h>

#endif /* _ASM_POWERPC_BUG_H */