1 /* SPDX-License-Identifier: GPL-2.0 */
2 /* Copyright (C) 2017 Andes Technology Corpora
3
4 #include <linux/init.h>
5 #include <linux/linkage.h>
6 #include <linux/export.h>
7 #include <asm/asm.h>
8 #include <asm/csr.h>
9 #include <asm/unistd.h>
10 #include <asm/thread_info.h>
11 #include <asm/asm-offsets.h>
12 #include <asm/ftrace.h>
13
14 .text
15
16 #define FENTRY_RA_OFFSET 8
17 #define ABI_SIZE_ON_STACK 80
18 #define ABI_A0 0
19 #define ABI_A1 8
20 #define ABI_A2 16
21 #define ABI_A3 24
22 #define ABI_A4 32
23 #define ABI_A5 40
24 #define ABI_A6 48
25 #define ABI_A7 56
26 #define ABI_T0 64
27 #define ABI_RA 72
28
29 .macro SAVE_ABI
30 addi sp, sp, -ABI_SIZE_ON_STACK
31
32 REG_S a0, ABI_A0(sp)
33 REG_S a1, ABI_A1(sp)
34 REG_S a2, ABI_A2(sp)
35 REG_S a3, ABI_A3(sp)
36 REG_S a4, ABI_A4(sp)
37 REG_S a5, ABI_A5(sp)
38 REG_S a6, ABI_A6(sp)
39 REG_S a7, ABI_A7(sp)
40 REG_S t0, ABI_T0(sp)
41 REG_S ra, ABI_RA(sp)
42 .endm
43
44 .macro RESTORE_ABI
45 REG_L a0, ABI_A0(sp)
46 REG_L a1, ABI_A1(sp)
47 REG_L a2, ABI_A2(sp)
48 REG_L a3, ABI_A3(sp)
49 REG_L a4, ABI_A4(sp)
50 REG_L a5, ABI_A5(sp)
51 REG_L a6, ABI_A6(sp)
52 REG_L a7, ABI_A7(sp)
53 REG_L t0, ABI_T0(sp)
54 REG_L ra, ABI_RA(sp)
55
56 addi sp, sp, ABI_SIZE_ON_STACK
57 .endm
58
59 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_ARGS
60
61 /**
62 * SAVE_ABI_REGS - save regs against the ftrace
63 *
64 * After the stack is established,
65 *
66 * 0(sp) stores the PC of the traced function w
67 * by &(fregs)->epc in tracing function. Note t
68 * function entry address should be computed wi
69 *
70 * 8(sp) stores the function return address (i.
71 * can be accessed by &(fregs)->ra in tracing f
72 *
73 * The other regs are saved at the respective l
74 * by the respective ftrace_regs member.
75 *
76 * Here is the layout of stack for your referen
77 *
78 * PT_SIZE_ON_STACK -> +++++++++
79 * + ..... +
80 * + a0-a7 + --++++-> ftr
81 * + t1 + --++++-> dir
82 * + s0 + --+ // frame
83 * + sp + +
84 * + ra + --+ // paren
85 * sp -> + epc + --+ // PC
86 * +++++++++
87 **/
88 .macro SAVE_ABI_REGS
89 mv t4, sp // Sav
90 addi sp, sp, -FREGS_SIZE_ON_STACK
91
92 REG_S t0, FREGS_EPC(sp)
93 REG_S x1, FREGS_RA(sp)
94 REG_S t4, FREGS_SP(sp) // Put
95 #ifdef HAVE_FUNCTION_GRAPH_FP_TEST
96 REG_S x8, FREGS_S0(sp)
97 #endif
98 REG_S x6, FREGS_T1(sp)
99
100 // save the arguments
101 REG_S x10, FREGS_A0(sp)
102 REG_S x11, FREGS_A1(sp)
103 REG_S x12, FREGS_A2(sp)
104 REG_S x13, FREGS_A3(sp)
105 REG_S x14, FREGS_A4(sp)
106 REG_S x15, FREGS_A5(sp)
107 REG_S x16, FREGS_A6(sp)
108 REG_S x17, FREGS_A7(sp)
109 .endm
110
111 .macro RESTORE_ABI_REGS, all=0
112 REG_L t0, FREGS_EPC(sp)
113 REG_L x1, FREGS_RA(sp)
114 #ifdef HAVE_FUNCTION_GRAPH_FP_TEST
115 REG_L x8, FREGS_S0(sp)
116 #endif
117 REG_L x6, FREGS_T1(sp)
118
119 // restore the arguments
120 REG_L x10, FREGS_A0(sp)
121 REG_L x11, FREGS_A1(sp)
122 REG_L x12, FREGS_A2(sp)
123 REG_L x13, FREGS_A3(sp)
124 REG_L x14, FREGS_A4(sp)
125 REG_L x15, FREGS_A5(sp)
126 REG_L x16, FREGS_A6(sp)
127 REG_L x17, FREGS_A7(sp)
128
129 addi sp, sp, FREGS_SIZE_ON_STACK
130 .endm
131
132 .macro PREPARE_ARGS
133 addi a0, t0, -FENTRY_RA_OFFSET
134 la a1, function_trace_op
135 REG_L a2, 0(a1)
136 mv a1, ra
137 mv a3, sp
138 .endm
139
140 #endif /* CONFIG_DYNAMIC_FTRACE_WITH_ARGS */
141
142 #ifndef CONFIG_DYNAMIC_FTRACE_WITH_ARGS
143 SYM_FUNC_START(ftrace_caller)
144 SAVE_ABI
145
146 addi a0, t0, -FENTRY_RA_OFFSET
147 la a1, function_trace_op
148 REG_L a2, 0(a1)
149 mv a1, ra
150 mv a3, sp
151
152 SYM_INNER_LABEL(ftrace_call, SYM_L_GLOBAL)
153 call ftrace_stub
154
155 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
156 addi a0, sp, ABI_RA
157 REG_L a1, ABI_T0(sp)
158 addi a1, a1, -FENTRY_RA_OFFSET
159 #ifdef HAVE_FUNCTION_GRAPH_FP_TEST
160 mv a2, s0
161 #endif
162 SYM_INNER_LABEL(ftrace_graph_call, SYM_L_GLOBA
163 call ftrace_stub
164 #endif
165 RESTORE_ABI
166 jr t0
167 SYM_FUNC_END(ftrace_caller)
168
169 #else /* CONFIG_DYNAMIC_FTRACE_WITH_ARGS */
170 SYM_FUNC_START(ftrace_caller)
171 mv t1, zero
172 SAVE_ABI_REGS
173 PREPARE_ARGS
174
175 SYM_INNER_LABEL(ftrace_call, SYM_L_GLOBAL)
176 call ftrace_stub
177
178 RESTORE_ABI_REGS
179 bnez t1, .Ldirect
180 jr t0
181 .Ldirect:
182 jr t1
183 SYM_FUNC_END(ftrace_caller)
184
185 #endif /* CONFIG_DYNAMIC_FTRACE_WITH_ARGS */
186
187 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
188 SYM_CODE_START(ftrace_stub_direct_tramp)
189 jr t0
190 SYM_CODE_END(ftrace_stub_direct_tramp)
191 #endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CA
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