1 /* SPDX-License-Identifier: GPL-2.0
2 *
3 * arch/sh/lib/mcount.S
4 *
5 * Copyright (C) 2008, 2009 Paul Mundt
6 * Copyright (C) 2008, 2009 Matt Fleming
7 */
8 #include <asm/ftrace.h>
9 #include <asm/thread_info.h>
10 #include <asm/asm-offsets.h>
11
12 #define MCOUNT_ENTER() \
13 mov.l r4, @-r15; \
14 mov.l r5, @-r15; \
15 mov.l r6, @-r15; \
16 mov.l r7, @-r15; \
17 sts.l pr, @-r15; \
18 \
19 mov.l @(20,r15),r4; \
20 sts pr, r5
21
22 #define MCOUNT_LEAVE() \
23 lds.l @r15+, pr; \
24 mov.l @r15+, r7; \
25 mov.l @r15+, r6; \
26 mov.l @r15+, r5; \
27 rts; \
28 mov.l @r15+, r4
29
30 #ifdef CONFIG_STACK_DEBUG
31 /*
32 * Perform diagnostic checks on the state of t
33 *
34 * Check for stack overflow. If there is less
35 * then it has overflowed.
36 *
37 * Make sure the stack pointer contains a vali
38 * addresses for kernel stacks are anywhere af
39 * (after __bss_stop) and anywhere in init_thr
40 */
41 #define STACK_CHECK()
42 mov #(THREAD_SIZE >> 10), r0;
43 shll8 r0;
44 shll2 r0;
45
46 /* r1 = sp & (THREAD_SIZE - 1) */
47 mov #-1, r1;
48 add r0, r1;
49 and r15, r1;
50
51 mov #TI_SIZE, r3;
52 mov #(STACK_WARN >> 8), r2;
53 shll8 r2;
54 add r3, r2;
55
56 /* Is the stack overflowing? */
57 cmp/hi r2, r1;
58 bf stack_panic;
59
60 /* If sp > __bss_stop then we're OK. *
61 mov.l .L_ebss, r1;
62 cmp/hi r1, r15;
63 bt 1f;
64
65 /* If sp < init_stack, we're not OK. *
66 mov.l .L_init_thread_union, r1;
67 cmp/hs r1, r15;
68 bf stack_panic;
69
70 /* If sp > init_stack && sp < __bss_st
71 add r0, r1;
72 cmp/hs r1, r15;
73 bt stack_panic;
74 1:
75 #else
76 #define STACK_CHECK()
77 #endif /* CONFIG_STACK_DEBUG */
78
79 .align 2
80 .globl _mcount
81 .type _mcount,@function
82 .globl mcount
83 .type mcount,@function
84 _mcount:
85 mcount:
86 STACK_CHECK()
87
88 #ifndef CONFIG_FUNCTION_TRACER
89 rts
90 nop
91 #else
92 MCOUNT_ENTER()
93
94 #ifdef CONFIG_DYNAMIC_FTRACE
95 .globl mcount_call
96 mcount_call:
97 mov.l .Lftrace_stub, r6
98 #else
99 mov.l .Lftrace_trace_function, r6
100 mov.l ftrace_stub, r7
101 cmp/eq r6, r7
102 bt skip_trace
103 mov.l @r6, r6
104 #endif
105
106 jsr @r6
107 nop
108
109 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
110 mov.l .Lftrace_graph_return, r6
111 mov.l .Lftrace_stub, r7
112 cmp/eq r6, r7
113 bt 1f
114
115 mov.l .Lftrace_graph_caller, r0
116 jmp @r0
117 nop
118
119 1:
120 mov.l .Lftrace_graph_entry, r6
121 mov.l .Lftrace_graph_entry_stub, r7
122 cmp/eq r6, r7
123 bt skip_trace
124
125 mov.l .Lftrace_graph_caller, r0
126 jmp @r0
127 nop
128
129 .align 2
130 .Lftrace_graph_return:
131 .long ftrace_graph_return
132 .Lftrace_graph_entry:
133 .long ftrace_graph_entry
134 .Lftrace_graph_entry_stub:
135 .long ftrace_graph_entry_stub
136 .Lftrace_graph_caller:
137 .long ftrace_graph_caller
138 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
139
140 .globl skip_trace
141 skip_trace:
142 MCOUNT_LEAVE()
143
144 .align 2
145 .Lftrace_trace_function:
146 .long ftrace_trace_function
147
148 #ifdef CONFIG_DYNAMIC_FTRACE
149 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
150 /*
151 * NOTE: Do not move either ftrace_graph_call
152 * as this will affect the calculation of GRAP
153 */
154 .globl ftrace_graph_call
155 ftrace_graph_call:
156 mov.l .Lskip_trace, r0
157 jmp @r0
158 nop
159
160 .align 2
161 .Lskip_trace:
162 .long skip_trace
163 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
164
165 .globl ftrace_caller
166 ftrace_caller:
167 MCOUNT_ENTER()
168
169 .globl ftrace_call
170 ftrace_call:
171 mov.l .Lftrace_stub, r6
172 jsr @r6
173 nop
174
175 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
176 bra ftrace_graph_call
177 nop
178 #else
179 MCOUNT_LEAVE()
180 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
181 #endif /* CONFIG_DYNAMIC_FTRACE */
182
183 .align 2
184
185 /*
186 * NOTE: From here on the locations of the .Lf
187 * ftrace_stub itself are fixed. Adding additi
188 * the displacement for the memory table and b
189 * Place new labels either after the ftrace_st
190 * ftrace_caller. You have been warned.
191 */
192 .Lftrace_stub:
193 .long ftrace_stub
194
195 .globl ftrace_stub
196 ftrace_stub:
197 rts
198 nop
199
200 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
201 .globl ftrace_graph_caller
202 ftrace_graph_caller:
203 mov.l 2f, r1
204 jmp @r1
205 nop
206 1:
207 /*
208 * MCOUNT_ENTER() pushed 5 registers o
209 * the stack address containing our re
210 * r15 + 20.
211 */
212 mov #20, r0
213 add r15, r0
214 mov r0, r4
215
216 mov.l .Lprepare_ftrace_return, r0
217 jsr @r0
218 nop
219
220 MCOUNT_LEAVE()
221
222 .align 2
223 2: .long skip_trace
224 .Lprepare_ftrace_return:
225 .long prepare_ftrace_return
226
227 .globl return_to_handler
228 return_to_handler:
229 /*
230 * Save the return values.
231 */
232 mov.l r0, @-r15
233 mov.l r1, @-r15
234
235 mov #0, r4
236
237 mov.l .Lftrace_return_to_handler, r0
238 jsr @r0
239 nop
240
241 /*
242 * The return value from ftrace_return
243 * address that we should return to.
244 */
245 lds r0, pr
246 mov.l @r15+, r1
247 rts
248 mov.l @r15+, r0
249
250
251 .align 2
252 .Lftrace_return_to_handler:
253 .long ftrace_return_to_handler
254 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
255 #endif /* CONFIG_FUNCTION_TRACER */
256
257 #ifdef CONFIG_STACK_DEBUG
258 .globl stack_panic
259 stack_panic:
260 mov.l .Ldump_stack, r0
261 jsr @r0
262 nop
263
264 mov.l .Lpanic, r0
265 jsr @r0
266 mov.l .Lpanic_s, r4
267
268 rts
269 nop
270
271 .align 2
272 .L_init_thread_union:
273 .long init_thread_union
274 .L_ebss:
275 .long __bss_stop
276 .Lpanic:
277 .long panic
278 .Lpanic_s:
279 .long .Lpanic_str
280 .Ldump_stack:
281 .long dump_stack
282
283 .section .rodata
284 .align 2
285 .Lpanic_str:
286 .string "Stack error"
287 #endif /* CONFIG_STACK_DEBUG */
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