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1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef __ASM_CRISv10_ARCH_BUG_H
3 #define __ASM_CRISv10_ARCH_BUG_H
4 
5 #include <linux/stringify.h>
6 
7 #ifdef CONFIG_BUG
8 #ifdef CONFIG_DEBUG_BUGVERBOSE
9 /* The BUG() macro is used for marking obviously incorrect code paths.
10  * It will cause a message with the file name and line number to be printed,
11  * and then cause an oops.  The message is actually printed by handle_BUG()
12  * in arch/cris/kernel/traps.c, and the reason we use this method of storing
13  * the file name and line number is that we do not want to affect the registers
14  * by calling printk() before causing the oops.
15  */
16 
17 #define BUG_PREFIX 0x0D7F
18 #define BUG_MAGIC  0x00001234
19 
20 struct bug_frame {
21 	unsigned short prefix;
22 	unsigned int magic;
23 	unsigned short clear;
24 	unsigned short movu;
25 	unsigned short line;
26 	unsigned short jump;
27 	unsigned char *filename;
28 };
29 
30 #if 0
31 /* Unfortunately this version of the macro does not work due to a problem
32  * with the compiler (aka a bug) when compiling with -O2, which sometimes
33  * erroneously causes the second input to be stored in a register...
34  */
35 #define BUG()								\
36 	__asm__ __volatile__ ("clear.d [" __stringify(BUG_MAGIC) "]\n\t"\
37 				"movu.w %0,$r0\n\t"			\
38 				"jump %1\n\t"				\
39 				: : "i" (__LINE__), "i" (__FILE__))
40 #else
41 /* This version will have to do for now, until the compiler is fixed.
42  * The drawbacks of this version are that the file name will appear multiple
43  * times in the .rodata section, and that __LINE__ and __FILE__ can probably
44  * not be used like this with newer versions of gcc.
45  */
46 #define BUG()								\
47 do {									\
48 	__asm__ __volatile__ ("clear.d [" __stringify(BUG_MAGIC) "]\n\t"\
49 			      "movu.w " __stringify(__LINE__) ",$r0\n\t"\
50 			      "jump 0f\n\t"				\
51 			      ".section .rodata\n"			\
52 			      "0:\t.string \"" __FILE__ "\"\n\t"	\
53 			      ".previous");				\
54 	unreachable();							\
55 } while (0)
56 #endif
57 
58 #else
59 
60 /* This just causes an oops. */
61 #define BUG()								\
62 do {									\
63 	barrier_before_unreachable();					\
64 	__builtin_trap();						\
65 } while (0)
66 
67 #endif
68 
69 #define HAVE_ARCH_BUG
70 #endif
71 
72 #include <asm-generic/bug.h>
73 
74 #endif
75