xref: /openbmc/linux/arch/s390/kernel/mcount.S (revision 6774def6)
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#include <asm/ptrace.h>
12
13	.section .kprobes.text, "ax"
14
15ENTRY(ftrace_stub)
16	br	%r14
17
18#define STACK_FRAME_SIZE  (STACK_FRAME_OVERHEAD + __PT_SIZE)
19#define STACK_PTREGS	  (STACK_FRAME_OVERHEAD)
20#define STACK_PTREGS_GPRS (STACK_PTREGS + __PT_GPRS)
21#define STACK_PTREGS_PSW  (STACK_PTREGS + __PT_PSW)
22
23ENTRY(_mcount)
24	br	%r14
25
26ENTRY(ftrace_caller)
27	.globl	ftrace_regs_caller
28	.set	ftrace_regs_caller,ftrace_caller
29	lgr	%r1,%r15
30	aghi	%r15,-STACK_FRAME_SIZE
31	stg	%r1,__SF_BACKCHAIN(%r15)
32	stg	%r1,(STACK_PTREGS_GPRS+15*8)(%r15)
33	stg	%r0,(STACK_PTREGS_PSW+8)(%r15)
34	stmg	%r2,%r14,(STACK_PTREGS_GPRS+2*8)(%r15)
35#ifdef CONFIG_HAVE_MARCH_Z196_FEATURES
36	aghik	%r2,%r0,-MCOUNT_INSN_SIZE
37	lgrl	%r4,function_trace_op
38	lgrl	%r1,ftrace_trace_function
39#else
40	lgr	%r2,%r0
41	aghi	%r2,-MCOUNT_INSN_SIZE
42	larl	%r4,function_trace_op
43	lg	%r4,0(%r4)
44	larl	%r1,ftrace_trace_function
45	lg	%r1,0(%r1)
46#endif
47	lgr	%r3,%r14
48	la	%r5,STACK_PTREGS(%r15)
49	basr	%r14,%r1
50#ifdef CONFIG_FUNCTION_GRAPH_TRACER
51# The j instruction gets runtime patched to a nop instruction.
52# See ftrace_enable_ftrace_graph_caller.
53ENTRY(ftrace_graph_caller)
54	j	ftrace_graph_caller_end
55	lg	%r2,(STACK_PTREGS_GPRS+14*8)(%r15)
56	lg	%r3,(STACK_PTREGS_PSW+8)(%r15)
57	brasl	%r14,prepare_ftrace_return
58	stg	%r2,(STACK_PTREGS_GPRS+14*8)(%r15)
59ftrace_graph_caller_end:
60	.globl	ftrace_graph_caller_end
61#endif
62	lg	%r1,(STACK_PTREGS_PSW+8)(%r15)
63	lmg	%r2,%r15,(STACK_PTREGS_GPRS+2*8)(%r15)
64	br	%r1
65
66#ifdef CONFIG_FUNCTION_GRAPH_TRACER
67
68ENTRY(return_to_handler)
69	stmg	%r2,%r5,32(%r15)
70	lgr	%r1,%r15
71	aghi	%r15,-STACK_FRAME_OVERHEAD
72	stg	%r1,__SF_BACKCHAIN(%r15)
73	brasl	%r14,ftrace_return_to_handler
74	aghi	%r15,STACK_FRAME_OVERHEAD
75	lgr	%r14,%r2
76	lmg	%r2,%r5,32(%r15)
77	br	%r14
78
79#endif
80