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/* SPDX-License-Identifier: GPL-2.0 */
/*
* LoongArch specific _mcount support
*
* Copyright (C) 2022 Loongson Technology Corporation Limited
*/
#include <linux/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, -FGRET_REGS_SIZE
PTR_S a0, sp, FGRET_REGS_A0
PTR_S a1, sp, FGRET_REGS_A1
PTR_S zero, sp, FGRET_REGS_FP
move a0, sp
bl ftrace_return_to_handler
/* Restore the real parent address: a0 -> ra */
move ra, a0
PTR_L a0, sp, FGRET_REGS_A0
PTR_L a1, sp, FGRET_REGS_A1
PTR_ADDI sp, sp, FGRET_REGS_SIZE
jr ra
SYM_FUNC_END(return_to_handler)
#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
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