Files
2024-06-17 20:18:01 +08:00

163 lines
3.9 KiB
ArmAsm

/* SPDX-License-Identifier: GPL-2.0 */
/*
* Author: Jinyang He <hejinyang@loongson.cn>
* Author: Huacai Chen <chenhuacai@loongson.cn>
* Copyright (C) 2020-2021 Loongson Technology Corporation Limited
*/
#include <asm/export.h>
#include <asm/regdef.h>
#include <asm/stackframe.h>
#include <asm/ftrace.h>
#include <asm/unwind_hints.h>
.text
/*
* Due to -fpatchable-function-entry=2: the compiler inserted 2 NOPs before the
* regular C function prologue. When PC arrived here, the last 2 instructions
* as follows,
* move t0, ra
* bl callsite (for modules, callsite is a tramplione)
*
* modules tramplione as follows,
* addu16i.d t1, zero, callsite[31:16]
* lu32i.d t1, callsite[51:32]
* lu52i.d t1, t1, callsite[63:52]
* jirl zero, t1, callsite[15:0] >> 2
*
* See arch/loongarch/kernel/ftrace_dyn.c for details. Here, pay attention to
* that the T series regs are available and safe because each C functions
* follows the LoongArch psABI well.
*/
.macro ftrace_regs_entry allregs=0
PTR_ADDIU sp, sp, -PT_SIZE
/* Save trace function ra at PT_ERA */
PTR_S ra, sp, PT_ERA
/* Save parent ra at PT_R1(RA) */
PTR_S t0, sp, PT_R1
PTR_S a0, sp, PT_R4
PTR_S a1, sp, PT_R5
PTR_S a2, sp, PT_R6
PTR_S a3, sp, PT_R7
PTR_S a4, sp, PT_R8
PTR_S a5, sp, PT_R9
PTR_S a6, sp, PT_R10
PTR_S a7, sp, PT_R11
PTR_S fp, sp, PT_R22
.if \allregs
PTR_S t0, sp, PT_R12
PTR_S t1, sp, PT_R13
PTR_S t2, sp, PT_R14
PTR_S t3, sp, PT_R15
PTR_S t4, sp, PT_R16
PTR_S t5, sp, PT_R17
PTR_S t6, sp, PT_R18
PTR_S t7, sp, PT_R19
PTR_S t8, sp, PT_R20
PTR_S s0, sp, PT_R23
PTR_S s1, sp, PT_R24
PTR_S s2, sp, PT_R25
PTR_S s3, sp, PT_R26
PTR_S s4, sp, PT_R27
PTR_S s5, sp, PT_R28
PTR_S s6, sp, PT_R29
PTR_S s7, sp, PT_R30
PTR_S s8, sp, PT_R31
PTR_S tp, sp, PT_R2
PTR_S sp, sp, PT_R3
/* Clear it for later use as a flag sometimes. */
PTR_S zero, sp, PT_R0
PTR_S $r21, sp, PT_R21
.endif
UNWIND_HINT_REGS
.endm
SYM_CODE_START(ftrace_caller)
UNWIND_HINT
ftrace_regs_entry allregs=0
b ftrace_common
SYM_CODE_END(ftrace_caller)
#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
SYM_CODE_START(ftrace_regs_caller)
UNWIND_HINT
ftrace_regs_entry allregs=1
b ftrace_common
SYM_CODE_END(ftrace_regs_caller)
#endif
SYM_CODE_START(ftrace_common)
UNWIND_HINT_REGS
PTR_ADDIU a0, ra, -8 /* arg0: ip */
move a1, t0 /* arg1: parent_ip */
la.pcrel t1, function_trace_op
PTR_L a2, t1, 0 /* arg2: op */
move a3, sp /* arg3: regs */
.globl ftrace_call
ftrace_call:
bl ftrace_stub
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
.globl ftrace_graph_call
ftrace_graph_call:
nop /* b ftrace_graph_caller */
#endif
/*
* As we didn't use S series regs in this assmembly code and all calls
* are C function which will save S series regs by themselves, there is
* no need to restore S series regs. The T series is available and safe
* at the callsite, so there is no need to restore the T series regs.
*/
ftrace_common_return:
PTR_L a0, sp, PT_R4
PTR_L a1, sp, PT_R5
PTR_L a2, sp, PT_R6
PTR_L a3, sp, PT_R7
PTR_L a4, sp, PT_R8
PTR_L a5, sp, PT_R9
PTR_L a6, sp, PT_R10
PTR_L a7, sp, PT_R11
PTR_L fp, sp, PT_R22
PTR_L ra, sp, PT_R1
PTR_L t0, sp, PT_ERA
PTR_ADDIU sp, sp, PT_SIZE
UNWIND_HINT
jirl zero, t0, 0
SYM_CODE_END(ftrace_common)
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
SYM_CODE_START(ftrace_graph_caller)
UNWIND_HINT_REGS
PTR_L a0, sp, PT_ERA
PTR_ADDIU a0, a0, -8 /* arg0: self_addr */
PTR_ADDIU a1, sp, PT_R1 /* arg1: parent */
bl prepare_ftrace_return
b ftrace_common_return
SYM_CODE_END(ftrace_graph_caller)
SYM_CODE_START(return_to_handler)
UNWIND_HINT
/* save return value regs */
PTR_ADDIU sp, sp, -2 * SZREG
PTR_S a0, sp, 0
PTR_S a1, sp, SZREG
move a0, zero /* Has no check FP now. */
bl ftrace_return_to_handler
move ra, a0 /* parent ra */
/* restore return value regs */
PTR_L a0, sp, 0
PTR_L a1, sp, SZREG
PTR_ADDIU sp, sp, 2 * SZREG
jirl zero, ra, 0
SYM_CODE_END(return_to_handler)
#endif
SYM_FUNC_START(ftrace_stub)
jirl zero, ra, 0
SYM_FUNC_END(ftrace_stub)