diff options
Diffstat (limited to 'arch/loongarch/kernel/mcount.S')
-rw-r--r-- | arch/loongarch/kernel/mcount.S | 96 |
1 files changed, 96 insertions, 0 deletions
diff --git a/arch/loongarch/kernel/mcount.S b/arch/loongarch/kernel/mcount.S new file mode 100644 index 000000000000..8cdc1563cd33 --- /dev/null +++ b/arch/loongarch/kernel/mcount.S @@ -0,0 +1,96 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * LoongArch specific _mcount support + * + * Copyright (C) 2022 Loongson Technology Corporation Limited + */ + +#include <asm/export.h> +#include <asm/ftrace.h> +#include <asm/regdef.h> +#include <asm/stackframe.h> + + .text + +#define MCOUNT_S0_OFFSET (0) +#define MCOUNT_RA_OFFSET (SZREG) +#define MCOUNT_STACK_SIZE (2 * SZREG) + + .macro MCOUNT_SAVE_REGS + PTR_ADDI sp, sp, -MCOUNT_STACK_SIZE + PTR_S s0, sp, MCOUNT_S0_OFFSET + PTR_S ra, sp, MCOUNT_RA_OFFSET + move s0, a0 + .endm + + .macro MCOUNT_RESTORE_REGS + move a0, s0 + PTR_L ra, sp, MCOUNT_RA_OFFSET + PTR_L s0, sp, MCOUNT_S0_OFFSET + PTR_ADDI sp, sp, MCOUNT_STACK_SIZE + .endm + +SYM_FUNC_START(_mcount) + la.pcrel t1, ftrace_stub + la.pcrel t2, ftrace_trace_function /* Prepare t2 for (1) */ + PTR_L t2, t2, 0 + beq t1, t2, fgraph_trace + + MCOUNT_SAVE_REGS + + move a0, ra /* arg0: self return address */ + move a1, s0 /* arg1: parent's return address */ + jirl ra, t2, 0 /* (1) call *ftrace_trace_function */ + + MCOUNT_RESTORE_REGS + +fgraph_trace: +#ifdef CONFIG_FUNCTION_GRAPH_TRACER + la.pcrel t1, ftrace_stub + la.pcrel t3, ftrace_graph_return + PTR_L t3, t3, 0 + bne t1, t3, ftrace_graph_caller + la.pcrel t1, ftrace_graph_entry_stub + la.pcrel t3, ftrace_graph_entry + PTR_L t3, t3, 0 + bne t1, t3, ftrace_graph_caller +#endif + +SYM_INNER_LABEL(ftrace_stub, SYM_L_GLOBAL) + jr ra +#ifdef CONFIG_FUNCTION_GRAPH_TRACER +SYM_INNER_LABEL(ftrace_graph_func, SYM_L_GLOBAL) + bl ftrace_stub +#endif +SYM_FUNC_END(_mcount) +EXPORT_SYMBOL(_mcount) + +#ifdef CONFIG_FUNCTION_GRAPH_TRACER +SYM_FUNC_START(ftrace_graph_caller) + MCOUNT_SAVE_REGS + + PTR_ADDI a0, ra, -4 /* arg0: Callsite self return addr */ + PTR_ADDI a1, sp, MCOUNT_STACK_SIZE /* arg1: Callsite sp */ + move a2, s0 /* arg2: Callsite parent ra */ + bl prepare_ftrace_return + + MCOUNT_RESTORE_REGS + jr ra +SYM_FUNC_END(ftrace_graph_caller) + +SYM_FUNC_START(return_to_handler) + PTR_ADDI sp, sp, -2 * SZREG + PTR_S a0, sp, 0 + PTR_S a1, sp, SZREG + + bl ftrace_return_to_handler + + /* Restore the real parent address: a0 -> ra */ + move ra, a0 + + PTR_L a0, sp, 0 + PTR_L a1, sp, SZREG + PTR_ADDI sp, sp, 2 * SZREG + jr ra +SYM_FUNC_END(return_to_handler) +#endif /* CONFIG_FUNCTION_GRAPH_TRACER */ |