1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3 * LoongArch specific _mcount support
4 *
5 * Copyright (C) 2022 Loongson Technology Corp
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_
21 PTR_S s0, sp, MCOUNT_S0_OFFS
22 PTR_S ra, sp, MCOUNT_RA_OFFS
23 move s0, a0
24 .endm
25
26 .macro MCOUNT_RESTORE_REGS
27 move a0, s0
28 PTR_L ra, sp, MCOUNT_RA_OFFS
29 PTR_L s0, sp, MCOUNT_S0_OFFS
30 PTR_ADDI sp, sp, MCOUNT_STACK_S
31 .endm
32
33 SYM_FUNC_START(_mcount)
34 la.pcrel t1, ftrace_stub
35 la.pcrel t2, ftrace_trace_funct
36 PTR_L t2, t2, 0
37 beq t1, t2, fgraph_trace
38
39 MCOUNT_SAVE_REGS
40
41 move a0, ra
42 move a1, s0
43 jirl ra, t2, 0
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_retur
51 PTR_L t3, t3, 0
52 bne t1, t3, ftrace_graph_c
53 la.pcrel t1, ftrace_graph_entry
54 la.pcrel t3, ftrace_graph_entry
55 PTR_L t3, t3, 0
56 bne t1, t3, ftrace_graph_c
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_GLOBA
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
73 PTR_ADDI a1, sp, MCOUNT_STACK_S
74 move a2, s0
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_SI
83 PTR_S a0, sp, FGRET_REGS_A0
84 PTR_S a1, sp, FGRET_REGS_A1
85 PTR_S zero, sp, FGRET_REGS_F
86
87 move a0, sp
88 bl ftrace_return_to_handl
89
90 /* Restore the real parent address: a0
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_SIZ
96 jr ra
97 SYM_FUNC_END(return_to_handler)
98 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
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