1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3 * Copyright (C) 2022 Loongson Technology Corp
4 */
5
6 #include <asm/ftrace.h>
7 #include <asm/regdef.h>
8 #include <asm/stackframe.h>
9
10 .text
11 /*
12 * Due to -fpatchable-function-entry=2: the co
13 * regular C function prologue. When PC arrive
14 * are as follows:
15 * move t0, ra
16 * bl callsite (for modules,
17 *
18 * modules trampoline is as follows:
19 * lu12i.w t1, callsite[31:12]
20 * lu32i.d t1, callsite[51:32]
21 * lu52i.d t1, t1, callsite[63:52
22 * jirl zero, t1, callsite[11:
23 *
24 * See arch/loongarch/kernel/ftrace_dyn.c for
25 * that the T series regs are available and sa
26 * follows the LoongArch's psABI as well.
27 */
28
29 .macro ftrace_regs_entry allregs=0
30 PTR_ADDI sp, sp, -PT_SIZE
31 PTR_S t0, sp, PT_R1 /* Save
32 PTR_S a0, sp, PT_R4
33 PTR_S a1, sp, PT_R5
34 PTR_S a2, sp, PT_R6
35 PTR_S a3, sp, PT_R7
36 PTR_S a4, sp, PT_R8
37 PTR_S a5, sp, PT_R9
38 PTR_S a6, sp, PT_R10
39 PTR_S a7, sp, PT_R11
40 PTR_S fp, sp, PT_R22
41 .if \allregs
42 PTR_S tp, sp, PT_R2
43 PTR_S t0, sp, PT_R12
44 PTR_S t2, sp, PT_R14
45 PTR_S t3, sp, PT_R15
46 PTR_S t4, sp, PT_R16
47 PTR_S t5, sp, PT_R17
48 PTR_S t6, sp, PT_R18
49 PTR_S t7, sp, PT_R19
50 PTR_S t8, sp, PT_R20
51 PTR_S u0, sp, PT_R21
52 PTR_S s0, sp, PT_R23
53 PTR_S s1, sp, PT_R24
54 PTR_S s2, sp, PT_R25
55 PTR_S s3, sp, PT_R26
56 PTR_S s4, sp, PT_R27
57 PTR_S s5, sp, PT_R28
58 PTR_S s6, sp, PT_R29
59 PTR_S s7, sp, PT_R30
60 PTR_S s8, sp, PT_R31
61 /* Clear it for later use as a flag so
62 PTR_S zero, sp, PT_R0
63 .endif
64 PTR_S ra, sp, PT_ERA /* Save
65 move t1, zero
66 PTR_S t1, sp, PT_R13
67 PTR_ADDI t8, sp, PT_SIZE
68 PTR_S t8, sp, PT_R3
69 .endm
70
71 SYM_FUNC_START(ftrace_stub)
72 jr ra
73 SYM_FUNC_END(ftrace_stub)
74
75 SYM_CODE_START(ftrace_common)
76 UNWIND_HINT_UNDEFINED
77 PTR_ADDI a0, ra, -8 /* arg
78 move a1, t0 /* arg
79 la.pcrel t1, function_trace_op
80 PTR_L a2, t1, 0 /* arg
81 move a3, sp /* arg
82
83 SYM_INNER_LABEL(ftrace_call, SYM_L_GLOBAL)
84 bl ftrace_stub
85 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
86 SYM_INNER_LABEL(ftrace_graph_call, SYM_L_GLOBA
87 nop /* b f
88 #endif
89
90 /*
91 * As we didn't use S series regs in this assm
92 * are C function which will save S series reg
93 * no need to restore S series regs. The T ser
94 * at the callsite, so there is no need to res
95 */
96 ftrace_common_return:
97 PTR_L ra, sp, PT_R1
98 PTR_L a0, sp, PT_R4
99 PTR_L a1, sp, PT_R5
100 PTR_L a2, sp, PT_R6
101 PTR_L a3, sp, PT_R7
102 PTR_L a4, sp, PT_R8
103 PTR_L a5, sp, PT_R9
104 PTR_L a6, sp, PT_R10
105 PTR_L a7, sp, PT_R11
106 PTR_L fp, sp, PT_R22
107 PTR_L t0, sp, PT_ERA
108 PTR_L t1, sp, PT_R13
109 PTR_ADDI sp, sp, PT_SIZE
110 bnez t1, .Ldirect
111 jr t0
112 .Ldirect:
113 jr t1
114 SYM_CODE_END(ftrace_common)
115
116 SYM_CODE_START(ftrace_caller)
117 UNWIND_HINT_UNDEFINED
118 ftrace_regs_entry allregs=0
119 b ftrace_common
120 SYM_CODE_END(ftrace_caller)
121
122 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
123 SYM_CODE_START(ftrace_regs_caller)
124 UNWIND_HINT_UNDEFINED
125 ftrace_regs_entry allregs=1
126 b ftrace_common
127 SYM_CODE_END(ftrace_regs_caller)
128 #endif
129
130 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
131 SYM_CODE_START(ftrace_graph_caller)
132 UNWIND_HINT_UNDEFINED
133 PTR_L a0, sp, PT_ERA
134 PTR_ADDI a0, a0, -8 /* arg
135 PTR_ADDI a1, sp, PT_R1 /* arg
136 bl prepare_ftrace_return
137 b ftrace_common_return
138 SYM_CODE_END(ftrace_graph_caller)
139
140 SYM_CODE_START(return_to_handler)
141 UNWIND_HINT_UNDEFINED
142 /* Save return value regs */
143 PTR_ADDI sp, sp, -FGRET_REGS_SI
144 PTR_S a0, sp, FGRET_REGS_A0
145 PTR_S a1, sp, FGRET_REGS_A1
146 PTR_S zero, sp, FGRET_REGS_F
147
148 move a0, sp
149 bl ftrace_return_to_handl
150 move ra, a0
151
152 /* Restore return value regs */
153 PTR_L a0, sp, FGRET_REGS_A0
154 PTR_L a1, sp, FGRET_REGS_A1
155 PTR_ADDI sp, sp, FGRET_REGS_SIZ
156
157 jr ra
158 SYM_CODE_END(return_to_handler)
159 #endif
160
161 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
162 SYM_CODE_START(ftrace_stub_direct_tramp)
163 UNWIND_HINT_UNDEFINED
164 jr t0
165 SYM_CODE_END(ftrace_stub_direct_tramp)
166 #endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CA
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