1 | /* SPDX-License-Identifier: GPL-2.0 */ |
2 | /* |
3 | * LoongArch specific _mcount support |
4 | * |
5 | * Copyright (C) 2022 Loongson Technology Corporation Limited |
6 | */ |
7 | |
8 | #include <linux/export.h> |
9 | #include <asm/ftrace.h> |
10 | #include <asm/regdef.h> |
11 | #include <asm/stackframe.h> |
12 | |
13 | .text |
14 | |
15 | #define MCOUNT_S0_OFFSET (0) |
16 | #define MCOUNT_RA_OFFSET (SZREG) |
17 | #define MCOUNT_STACK_SIZE (2 * SZREG) |
18 | |
19 | .macro MCOUNT_SAVE_REGS |
20 | PTR_ADDI sp, sp, -MCOUNT_STACK_SIZE |
21 | PTR_S s0, sp, MCOUNT_S0_OFFSET |
22 | PTR_S ra, sp, MCOUNT_RA_OFFSET |
23 | move s0, a0 |
24 | .endm |
25 | |
26 | .macro MCOUNT_RESTORE_REGS |
27 | move a0, s0 |
28 | PTR_L ra, sp, MCOUNT_RA_OFFSET |
29 | PTR_L s0, sp, MCOUNT_S0_OFFSET |
30 | PTR_ADDI sp, sp, MCOUNT_STACK_SIZE |
31 | .endm |
32 | |
33 | SYM_FUNC_START(_mcount) |
34 | la.pcrel t1, ftrace_stub |
35 | la.pcrel t2, ftrace_trace_function /* Prepare t2 for (1) */ |
36 | PTR_L t2, t2, 0 |
37 | beq t1, t2, fgraph_trace |
38 | |
39 | MCOUNT_SAVE_REGS |
40 | |
41 | move a0, ra /* arg0: self return address */ |
42 | move a1, s0 /* arg1: parent's return address */ |
43 | jirl ra, t2, 0 /* (1) call *ftrace_trace_function */ |
44 | |
45 | MCOUNT_RESTORE_REGS |
46 | |
47 | fgraph_trace: |
48 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
49 | la.pcrel t1, ftrace_stub |
50 | la.pcrel t3, ftrace_graph_return |
51 | PTR_L t3, t3, 0 |
52 | bne t1, t3, ftrace_graph_caller |
53 | la.pcrel t1, ftrace_graph_entry_stub |
54 | la.pcrel t3, ftrace_graph_entry |
55 | PTR_L t3, t3, 0 |
56 | bne t1, t3, ftrace_graph_caller |
57 | #endif |
58 | |
59 | SYM_INNER_LABEL(ftrace_stub, SYM_L_GLOBAL) |
60 | jr ra |
61 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
62 | SYM_INNER_LABEL(ftrace_graph_func, SYM_L_GLOBAL) |
63 | bl ftrace_stub |
64 | #endif |
65 | SYM_FUNC_END(_mcount) |
66 | EXPORT_SYMBOL(_mcount) |
67 | |
68 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
69 | SYM_FUNC_START(ftrace_graph_caller) |
70 | MCOUNT_SAVE_REGS |
71 | |
72 | PTR_ADDI a0, ra, -4 /* arg0: Callsite self return addr */ |
73 | PTR_ADDI a1, sp, MCOUNT_STACK_SIZE /* arg1: Callsite sp */ |
74 | move a2, s0 /* arg2: Callsite parent ra */ |
75 | bl prepare_ftrace_return |
76 | |
77 | MCOUNT_RESTORE_REGS |
78 | jr ra |
79 | SYM_FUNC_END(ftrace_graph_caller) |
80 | |
81 | SYM_FUNC_START(return_to_handler) |
82 | PTR_ADDI sp, sp, -FGRET_REGS_SIZE |
83 | PTR_S a0, sp, FGRET_REGS_A0 |
84 | PTR_S a1, sp, FGRET_REGS_A1 |
85 | PTR_S zero, sp, FGRET_REGS_FP |
86 | |
87 | move a0, sp |
88 | bl ftrace_return_to_handler |
89 | |
90 | /* Restore the real parent address: a0 -> ra */ |
91 | move ra, a0 |
92 | |
93 | PTR_L a0, sp, FGRET_REGS_A0 |
94 | PTR_L a1, sp, FGRET_REGS_A1 |
95 | PTR_ADDI sp, sp, FGRET_REGS_SIZE |
96 | jr ra |
97 | SYM_FUNC_END(return_to_handler) |
98 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ |
99 | |