1/*
 2 * Copyright IBM Corp. 2008, 2009
 3 *
 4 *   Author(s): Heiko Carstens <heiko.carstens@de.ibm.com>,
 5 *
 6 */
 7
 8#include <linux/linkage.h>
 9#include <asm/asm-offsets.h>
10#include <asm/ftrace.h>
11
12	.section .kprobes.text, "ax"
13
14ENTRY(ftrace_stub)
15	br	%r14
16
17ENTRY(_mcount)
18#ifdef CONFIG_DYNAMIC_FTRACE
19	br	%r14
20
21ENTRY(ftrace_caller)
22#endif
23	larl	%r1,function_trace_stop
24	icm	%r1,0xf,0(%r1)
25	bnzr	%r14
26	stmg	%r2,%r5,32(%r15)
27	stg	%r14,112(%r15)
28	lgr	%r1,%r15
29	aghi	%r15,-160
30	stg	%r1,__SF_BACKCHAIN(%r15)
31	lgr	%r2,%r14
32	lg	%r3,168(%r15)
33	aghi	%r2,-MCOUNT_INSN_SIZE
34	larl	%r14,ftrace_trace_function
35	lg	%r14,0(%r14)
36	basr	%r14,%r14
37#ifdef CONFIG_FUNCTION_GRAPH_TRACER
38	lg	%r2,168(%r15)
39	lg	%r3,272(%r15)
40ENTRY(ftrace_graph_caller)
41# The bras instruction gets runtime patched to call prepare_ftrace_return.
42# See ftrace_enable_ftrace_graph_caller. The patched instruction is:
43#	bras	%r14,prepare_ftrace_return
44	bras	%r14,0f
450:	stg	%r2,168(%r15)
46#endif
47	aghi	%r15,160
48	lmg	%r2,%r5,32(%r15)
49	lg	%r14,112(%r15)
50	br	%r14
51
52#ifdef CONFIG_FUNCTION_GRAPH_TRACER
53
54ENTRY(return_to_handler)
55	stmg	%r2,%r5,32(%r15)
56	lgr	%r1,%r15
57	aghi	%r15,-160
58	stg	%r1,__SF_BACKCHAIN(%r15)
59	brasl	%r14,ftrace_return_to_handler
60	aghi	%r15,160
61	lgr	%r14,%r2
62	lmg	%r2,%r5,32(%r15)
63	br	%r14
64
65#endif