xref: /linux/arch/s390/include/asm/ftrace.h (revision 4949009eb8d40a441dcddcd96e101e77d31cf1b2)
1 #ifndef _ASM_S390_FTRACE_H
2 #define _ASM_S390_FTRACE_H
3 
4 #define ARCH_SUPPORTS_FTRACE_OPS 1
5 
6 #define MCOUNT_INSN_SIZE	24
7 #define MCOUNT_RETURN_FIXUP	18
8 
9 #ifndef __ASSEMBLY__
10 
11 #define ftrace_return_address(n) __builtin_return_address(n)
12 
13 void _mcount(void);
14 void ftrace_caller(void);
15 
16 extern char ftrace_graph_caller_end;
17 extern unsigned long ftrace_plt;
18 
19 struct dyn_arch_ftrace { };
20 
21 #define MCOUNT_ADDR ((unsigned long)_mcount)
22 #define FTRACE_ADDR ((unsigned long)ftrace_caller)
23 
24 #define KPROBE_ON_FTRACE_NOP	0
25 #define KPROBE_ON_FTRACE_CALL	1
26 
27 static inline unsigned long ftrace_call_adjust(unsigned long addr)
28 {
29 	return addr;
30 }
31 
32 struct ftrace_insn {
33 	u16 opc;
34 	s32 disp;
35 } __packed;
36 
37 static inline void ftrace_generate_nop_insn(struct ftrace_insn *insn)
38 {
39 #ifdef CONFIG_FUNCTION_TRACER
40 	/* jg .+24 */
41 	insn->opc = 0xc0f4;
42 	insn->disp = MCOUNT_INSN_SIZE / 2;
43 #endif
44 }
45 
46 static inline int is_ftrace_nop(struct ftrace_insn *insn)
47 {
48 #ifdef CONFIG_FUNCTION_TRACER
49 	if (insn->disp == MCOUNT_INSN_SIZE / 2)
50 		return 1;
51 #endif
52 	return 0;
53 }
54 
55 static inline void ftrace_generate_call_insn(struct ftrace_insn *insn,
56 					     unsigned long ip)
57 {
58 #ifdef CONFIG_FUNCTION_TRACER
59 	unsigned long target;
60 
61 	/* brasl r0,ftrace_caller */
62 	target = is_module_addr((void *) ip) ? ftrace_plt : FTRACE_ADDR;
63 	insn->opc = 0xc005;
64 	insn->disp = (target - ip) / 2;
65 #endif
66 }
67 
68 #endif /* __ASSEMBLY__ */
69 #endif /* _ASM_S390_FTRACE_H */
70