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/* SPDX-License-Identifier: GPL-2.0 */
/* Copyright (C) 2017 Andes Technology Corporation */
#include <linux/init.h>
#include <linux/linkage.h>
#include <linux/export.h>
#include <asm/asm.h>
#include <asm/csr.h>
#include <asm/unistd.h>
#include <asm/thread_info.h>
#include <asm/asm-offsets.h>
#include <asm/ftrace.h>
.text
#define FENTRY_RA_OFFSET 8
#define ABI_SIZE_ON_STACK 80
#define ABI_A0 0
#define ABI_A1 8
#define ABI_A2 16
#define ABI_A3 24
#define ABI_A4 32
#define ABI_A5 40
#define ABI_A6 48
#define ABI_A7 56
#define ABI_T0 64
#define ABI_RA 72
.macro SAVE_ABI
addi sp, sp, -ABI_SIZE_ON_STACK
REG_S a0, ABI_A0(sp)
REG_S a1, ABI_A1(sp)
REG_S a2, ABI_A2(sp)
REG_S a3, ABI_A3(sp)
REG_S a4, ABI_A4(sp)
REG_S a5, ABI_A5(sp)
REG_S a6, ABI_A6(sp)
REG_S a7, ABI_A7(sp)
REG_S t0, ABI_T0(sp)
REG_S ra, ABI_RA(sp)
.endm
.macro RESTORE_ABI
REG_L a0, ABI_A0(sp)
REG_L a1, ABI_A1(sp)
REG_L a2, ABI_A2(sp)
REG_L a3, ABI_A3(sp)
REG_L a4, ABI_A4(sp)
REG_L a5, ABI_A5(sp)
REG_L a6, ABI_A6(sp)
REG_L a7, ABI_A7(sp)
REG_L t0, ABI_T0(sp)
REG_L ra, ABI_RA(sp)
addi sp, sp, ABI_SIZE_ON_STACK
.endm
#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
/**
* SAVE_ABI_REGS - save regs against the pt_regs struct
*
* @all: tell if saving all the regs
*
* If all is set, all the regs will be saved, otherwise only ABI
* related regs (a0-a7,epc,ra and optional s0) will be saved.
*
* After the stack is established,
*
* 0(sp) stores the PC of the traced function which can be accessed
* by &(fregs)->regs->epc in tracing function. Note that the real
* function entry address should be computed with -FENTRY_RA_OFFSET.
*
* 8(sp) stores the function return address (i.e. parent IP) that
* can be accessed by &(fregs)->regs->ra in tracing function.
*
* The other regs are saved at the respective localtion and accessed
* by the respective pt_regs member.
*
* Here is the layout of stack for your reference.
*
* PT_SIZE_ON_STACK -> +++++++++
* + ..... +
* + t3-t6 +
* + s2-s11+
* + a0-a7 + --++++-> ftrace_caller saved
* + s1 + +
* + s0 + --+
* + t0-t2 + +
* + tp + +
* + gp + +
* + sp + +
* + ra + --+ // parent IP
* sp -> + epc + --+ // PC
* +++++++++
**/
.macro SAVE_ABI_REGS, all=0
addi sp, sp, -PT_SIZE_ON_STACK
REG_S t0, PT_EPC(sp)
REG_S x1, PT_RA(sp)
// save the ABI regs
REG_S x10, PT_A0(sp)
REG_S x11, PT_A1(sp)
REG_S x12, PT_A2(sp)
REG_S x13, PT_A3(sp)
REG_S x14, PT_A4(sp)
REG_S x15, PT_A5(sp)
REG_S x16, PT_A6(sp)
REG_S x17, PT_A7(sp)
// save the leftover regs
.if \all == 1
REG_S x2, PT_SP(sp)
REG_S x3, PT_GP(sp)
REG_S x4, PT_TP(sp)
REG_S x5, PT_T0(sp)
REG_S x6, PT_T1(sp)
REG_S x7, PT_T2(sp)
REG_S x8, PT_S0(sp)
REG_S x9, PT_S1(sp)
REG_S x18, PT_S2(sp)
REG_S x19, PT_S3(sp)
REG_S x20, PT_S4(sp)
REG_S x21, PT_S5(sp)
REG_S x22, PT_S6(sp)
REG_S x23, PT_S7(sp)
REG_S x24, PT_S8(sp)
REG_S x25, PT_S9(sp)
REG_S x26, PT_S10(sp)
REG_S x27, PT_S11(sp)
REG_S x28, PT_T3(sp)
REG_S x29, PT_T4(sp)
REG_S x30, PT_T5(sp)
REG_S x31, PT_T6(sp)
// save s0 if FP_TEST defined
.else
#ifdef HAVE_FUNCTION_GRAPH_FP_TEST
REG_S x8, PT_S0(sp)
#endif
.endif
.endm
.macro RESTORE_ABI_REGS, all=0
REG_L t0, PT_EPC(sp)
REG_L x1, PT_RA(sp)
REG_L x10, PT_A0(sp)
REG_L x11, PT_A1(sp)
REG_L x12, PT_A2(sp)
REG_L x13, PT_A3(sp)
REG_L x14, PT_A4(sp)
REG_L x15, PT_A5(sp)
REG_L x16, PT_A6(sp)
REG_L x17, PT_A7(sp)
.if \all == 1
REG_L x2, PT_SP(sp)
REG_L x3, PT_GP(sp)
REG_L x4, PT_TP(sp)
REG_L x6, PT_T1(sp)
REG_L x7, PT_T2(sp)
REG_L x8, PT_S0(sp)
REG_L x9, PT_S1(sp)
REG_L x18, PT_S2(sp)
REG_L x19, PT_S3(sp)
REG_L x20, PT_S4(sp)
REG_L x21, PT_S5(sp)
REG_L x22, PT_S6(sp)
REG_L x23, PT_S7(sp)
REG_L x24, PT_S8(sp)
REG_L x25, PT_S9(sp)
REG_L x26, PT_S10(sp)
REG_L x27, PT_S11(sp)
REG_L x28, PT_T3(sp)
REG_L x29, PT_T4(sp)
REG_L x30, PT_T5(sp)
REG_L x31, PT_T6(sp)
.else
#ifdef HAVE_FUNCTION_GRAPH_FP_TEST
REG_L x8, PT_S0(sp)
#endif
.endif
addi sp, sp, PT_SIZE_ON_STACK
.endm
.macro PREPARE_ARGS
addi a0, t0, -FENTRY_RA_OFFSET
la a1, function_trace_op
REG_L a2, 0(a1)
mv a1, ra
mv a3, sp
.endm
#endif /* CONFIG_DYNAMIC_FTRACE_WITH_REGS */
#ifndef CONFIG_DYNAMIC_FTRACE_WITH_REGS
SYM_FUNC_START(ftrace_caller)
SAVE_ABI
addi a0, t0, -FENTRY_RA_OFFSET
la a1, function_trace_op
REG_L a2, 0(a1)
mv a1, ra
mv a3, sp
SYM_INNER_LABEL(ftrace_call, SYM_L_GLOBAL)
call ftrace_stub
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
addi a0, sp, ABI_RA
REG_L a1, ABI_T0(sp)
addi a1, a1, -FENTRY_RA_OFFSET
#ifdef HAVE_FUNCTION_GRAPH_FP_TEST
mv a2, s0
#endif
SYM_INNER_LABEL(ftrace_graph_call, SYM_L_GLOBAL)
call ftrace_stub
#endif
RESTORE_ABI
jr t0
SYM_FUNC_END(ftrace_caller)
#else /* CONFIG_DYNAMIC_FTRACE_WITH_REGS */
SYM_FUNC_START(ftrace_regs_caller)
mv t1, zero
SAVE_ABI_REGS 1
PREPARE_ARGS
SYM_INNER_LABEL(ftrace_regs_call, SYM_L_GLOBAL)
call ftrace_stub
RESTORE_ABI_REGS 1
bnez t1, .Ldirect
jr t0
.Ldirect:
jr t1
SYM_FUNC_END(ftrace_regs_caller)
SYM_FUNC_START(ftrace_caller)
SAVE_ABI_REGS 0
PREPARE_ARGS
SYM_INNER_LABEL(ftrace_call, SYM_L_GLOBAL)
call ftrace_stub
RESTORE_ABI_REGS 0
jr t0
SYM_FUNC_END(ftrace_caller)
#endif /* CONFIG_DYNAMIC_FTRACE_WITH_REGS */
#ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
SYM_CODE_START(ftrace_stub_direct_tramp)
jr t0
SYM_CODE_END(ftrace_stub_direct_tramp)
#endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */
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