xref: /openbmc/linux/arch/riscv/kernel/mcount-dyn.S (revision 6c33a6f4)
1/* SPDX-License-Identifier: GPL-2.0 */
2/* Copyright (C) 2017 Andes Technology Corporation */
3
4#include <linux/init.h>
5#include <linux/linkage.h>
6#include <asm/asm.h>
7#include <asm/csr.h>
8#include <asm/unistd.h>
9#include <asm/thread_info.h>
10#include <asm/asm-offsets.h>
11#include <asm-generic/export.h>
12#include <asm/ftrace.h>
13
14	.text
15
16	.macro SAVE_ABI_STATE
17#ifdef CONFIG_FUNCTION_GRAPH_TRACER
18	addi    sp, sp, -48
19	sd      s0, 32(sp)
20	sd      ra, 40(sp)
21	addi    s0, sp, 48
22	sd      t0, 24(sp)
23	sd      t1, 16(sp)
24#ifdef HAVE_FUNCTION_GRAPH_FP_TEST
25	sd      t2, 8(sp)
26#endif
27#else
28	addi	sp, sp, -16
29	sd	s0, 0(sp)
30	sd	ra, 8(sp)
31	addi	s0, sp, 16
32#endif
33	.endm
34
35	.macro RESTORE_ABI_STATE
36#ifdef CONFIG_FUNCTION_GRAPH_TRACER
37	ld	s0, 32(sp)
38	ld	ra, 40(sp)
39	addi	sp, sp, 48
40#else
41	ld	ra, 8(sp)
42	ld	s0, 0(sp)
43	addi	sp, sp, 16
44#endif
45	.endm
46
47	.macro RESTORE_GRAPH_ARGS
48	ld	a0, 24(sp)
49	ld	a1, 16(sp)
50#ifdef HAVE_FUNCTION_GRAPH_FP_TEST
51	ld	a2, 8(sp)
52#endif
53	.endm
54
55ENTRY(ftrace_graph_caller)
56	addi	sp, sp, -16
57	sd	s0, 0(sp)
58	sd	ra, 8(sp)
59	addi	s0, sp, 16
60ftrace_graph_call:
61	.global ftrace_graph_call
62	/*
63	 * Calling ftrace_enable/disable_ftrace_graph_caller would overwrite the
64	 * call below.  Check ftrace_modify_all_code for details.
65	 */
66	call	ftrace_stub
67	ld	ra, 8(sp)
68	ld	s0, 0(sp)
69	addi	sp, sp, 16
70	ret
71ENDPROC(ftrace_graph_caller)
72
73ENTRY(ftrace_caller)
74	/*
75	 * a0: the address in the caller when calling ftrace_caller
76	 * a1: the caller's return address
77	 * a2: the address of global variable function_trace_op
78	 */
79	ld	a1, -8(s0)
80	addi	a0, ra, -MCOUNT_INSN_SIZE
81	la	t5, function_trace_op
82	ld	a2, 0(t5)
83
84#ifdef CONFIG_FUNCTION_GRAPH_TRACER
85	/*
86	 * the graph tracer (specifically, prepare_ftrace_return) needs these
87	 * arguments but for now the function tracer occupies the regs, so we
88	 * save them in temporary regs to recover later.
89	 */
90	addi	t0, s0, -8
91	mv	t1, a0
92#ifdef HAVE_FUNCTION_GRAPH_FP_TEST
93	ld	t2, -16(s0)
94#endif
95#endif
96
97	SAVE_ABI_STATE
98ftrace_call:
99	.global ftrace_call
100	/*
101	 * For the dynamic ftrace to work, here we should reserve at least
102	 * 8 bytes for a functional auipc-jalr pair.  The following call
103	 * serves this purpose.
104	 *
105	 * Calling ftrace_update_ftrace_func would overwrite the nops below.
106	 * Check ftrace_modify_all_code for details.
107	 */
108	call	ftrace_stub
109
110#ifdef CONFIG_FUNCTION_GRAPH_TRACER
111	RESTORE_GRAPH_ARGS
112	call	ftrace_graph_caller
113#endif
114
115	RESTORE_ABI_STATE
116	ret
117ENDPROC(ftrace_caller)
118
119#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
120	.macro SAVE_ALL
121	addi	sp, sp, -(PT_SIZE_ON_STACK+16)
122	sd	s0, (PT_SIZE_ON_STACK)(sp)
123	sd	ra, (PT_SIZE_ON_STACK+8)(sp)
124	addi	s0, sp, (PT_SIZE_ON_STACK+16)
125
126	sd x1,  PT_RA(sp)
127	sd x2,  PT_SP(sp)
128	sd x3,  PT_GP(sp)
129	sd x4,  PT_TP(sp)
130	sd x5,  PT_T0(sp)
131	sd x6,  PT_T1(sp)
132	sd x7,  PT_T2(sp)
133	sd x8,  PT_S0(sp)
134	sd x9,  PT_S1(sp)
135	sd x10, PT_A0(sp)
136	sd x11, PT_A1(sp)
137	sd x12, PT_A2(sp)
138	sd x13, PT_A3(sp)
139	sd x14, PT_A4(sp)
140	sd x15, PT_A5(sp)
141	sd x16, PT_A6(sp)
142	sd x17, PT_A7(sp)
143	sd x18, PT_S2(sp)
144	sd x19, PT_S3(sp)
145	sd x20, PT_S4(sp)
146	sd x21, PT_S5(sp)
147	sd x22, PT_S6(sp)
148	sd x23, PT_S7(sp)
149	sd x24, PT_S8(sp)
150	sd x25, PT_S9(sp)
151	sd x26, PT_S10(sp)
152	sd x27, PT_S11(sp)
153	sd x28, PT_T3(sp)
154	sd x29, PT_T4(sp)
155	sd x30, PT_T5(sp)
156	sd x31, PT_T6(sp)
157	.endm
158
159	.macro RESTORE_ALL
160	ld x1,  PT_RA(sp)
161	ld x2,  PT_SP(sp)
162	ld x3,  PT_GP(sp)
163	ld x4,  PT_TP(sp)
164	ld x5,  PT_T0(sp)
165	ld x6,  PT_T1(sp)
166	ld x7,  PT_T2(sp)
167	ld x8,  PT_S0(sp)
168	ld x9,  PT_S1(sp)
169	ld x10, PT_A0(sp)
170	ld x11, PT_A1(sp)
171	ld x12, PT_A2(sp)
172	ld x13, PT_A3(sp)
173	ld x14, PT_A4(sp)
174	ld x15, PT_A5(sp)
175	ld x16, PT_A6(sp)
176	ld x17, PT_A7(sp)
177	ld x18, PT_S2(sp)
178	ld x19, PT_S3(sp)
179	ld x20, PT_S4(sp)
180	ld x21, PT_S5(sp)
181	ld x22, PT_S6(sp)
182	ld x23, PT_S7(sp)
183	ld x24, PT_S8(sp)
184	ld x25, PT_S9(sp)
185	ld x26, PT_S10(sp)
186	ld x27, PT_S11(sp)
187	ld x28, PT_T3(sp)
188	ld x29, PT_T4(sp)
189	ld x30, PT_T5(sp)
190	ld x31, PT_T6(sp)
191
192	ld	s0, (PT_SIZE_ON_STACK)(sp)
193	ld	ra, (PT_SIZE_ON_STACK+8)(sp)
194	addi	sp, sp, (PT_SIZE_ON_STACK+16)
195	.endm
196
197	.macro RESTORE_GRAPH_REG_ARGS
198	ld	a0, PT_T0(sp)
199	ld	a1, PT_T1(sp)
200#ifdef HAVE_FUNCTION_GRAPH_FP_TEST
201	ld	a2, PT_T2(sp)
202#endif
203	.endm
204
205/*
206 * Most of the contents are the same as ftrace_caller.
207 */
208ENTRY(ftrace_regs_caller)
209	/*
210	 * a3: the address of all registers in the stack
211	 */
212	ld	a1, -8(s0)
213	addi	a0, ra, -MCOUNT_INSN_SIZE
214	la	t5, function_trace_op
215	ld	a2, 0(t5)
216	addi	a3, sp, -(PT_SIZE_ON_STACK+16)
217
218#ifdef CONFIG_FUNCTION_GRAPH_TRACER
219	addi	t0, s0, -8
220	mv	t1, a0
221#ifdef HAVE_FUNCTION_GRAPH_FP_TEST
222	ld	t2, -16(s0)
223#endif
224#endif
225	SAVE_ALL
226
227ftrace_regs_call:
228	.global ftrace_regs_call
229	call	ftrace_stub
230
231#ifdef CONFIG_FUNCTION_GRAPH_TRACER
232	RESTORE_GRAPH_REG_ARGS
233	call	ftrace_graph_caller
234#endif
235
236	RESTORE_ALL
237	ret
238ENDPROC(ftrace_regs_caller)
239#endif /* CONFIG_DYNAMIC_FTRACE_WITH_REGS */
240