1 /* SPDX-License-Identifier: GPL-2.0 */
3 * LoongArch specific _mcount support
5 * Copyright (C) 2022 Loongson Technology Corporation Limited
8 #include <linux/export.h>
9 #include <asm/ftrace.h>
10 #include <asm/regdef.h>
11 #include <asm/stackframe.h>
15 #define MCOUNT_S0_OFFSET (0)
16 #define MCOUNT_RA_OFFSET (SZREG)
17 #define MCOUNT_STACK_SIZE (2 * SZREG)
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
26 .macro MCOUNT_RESTORE_REGS
28 PTR_L ra, sp, MCOUNT_RA_OFFSET
29 PTR_L s0, sp, MCOUNT_S0_OFFSET
30 PTR_ADDI sp, sp, MCOUNT_STACK_SIZE
33 SYM_FUNC_START(_mcount)
34 la.pcrel t1, ftrace_stub
35 la.pcrel t2, ftrace_trace_function /* Prepare t2 for (1) */
37 beq t1, t2, fgraph_trace
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 */
48 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
49 la.pcrel t1, ftrace_stub
50 la.pcrel t3, ftrace_graph_return
52 bne t1, t3, ftrace_graph_caller
53 la.pcrel t1, ftrace_graph_entry_stub
54 la.pcrel t3, ftrace_graph_entry
56 bne t1, t3, ftrace_graph_caller
59 SYM_INNER_LABEL(ftrace_stub, SYM_L_GLOBAL)
61 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
62 SYM_INNER_LABEL(ftrace_graph_func, SYM_L_GLOBAL)
66 EXPORT_SYMBOL(_mcount)
68 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
69 SYM_FUNC_START(ftrace_graph_caller)
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
79 SYM_FUNC_END(ftrace_graph_caller)
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
88 bl ftrace_return_to_handler
90 /* Restore the real parent address: a0 -> ra */
93 PTR_L a0, sp, FGRET_REGS_A0
94 PTR_L a1, sp, FGRET_REGS_A1
95 PTR_ADDI sp, sp, FGRET_REGS_SIZE
97 SYM_FUNC_END(return_to_handler)
98 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */