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/*
* MIPS specific _mcount support
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive for
* more details.
*
* Copyright (C) 2009 Lemote Inc. & DSLab, Lanzhou University, China
* Copyright (C) 2010 DSLab, Lanzhou University, China
* Author: Wu Zhangjin <wuzhangjin@gmail.com>
*/
#include <asm/regdef.h>
#include <asm/stackframe.h>
#include <asm/ftrace.h>
.text
.set noreorder
.set noat
.macro MCOUNT_SAVE_REGS
PTR_SUBU sp, PT_SIZE
PTR_S ra, PT_R31(sp)
PTR_S AT, PT_R1(sp)
PTR_S a0, PT_R4(sp)
PTR_S a1, PT_R5(sp)
PTR_S a2, PT_R6(sp)
PTR_S a3, PT_R7(sp)
#ifdef CONFIG_64BIT
PTR_S a4, PT_R8(sp)
PTR_S a5, PT_R9(sp)
PTR_S a6, PT_R10(sp)
PTR_S a7, PT_R11(sp)
#endif
.endm
.macro MCOUNT_RESTORE_REGS
PTR_L ra, PT_R31(sp)
PTR_L AT, PT_R1(sp)
PTR_L a0, PT_R4(sp)
PTR_L a1, PT_R5(sp)
PTR_L a2, PT_R6(sp)
PTR_L a3, PT_R7(sp)
#ifdef CONFIG_64BIT
PTR_L a4, PT_R8(sp)
PTR_L a5, PT_R9(sp)
PTR_L a6, PT_R10(sp)
PTR_L a7, PT_R11(sp)
#endif
PTR_ADDIU sp, PT_SIZE
.endm
.macro RETURN_BACK
jr ra
move ra, AT
.endm
/*
* The -mmcount-ra-address option of gcc 4.5 uses register $12 to pass
* the location of the parent's return address.
*/
#define MCOUNT_RA_ADDRESS_REG $12
#ifdef CONFIG_DYNAMIC_FTRACE
NESTED(ftrace_caller, PT_SIZE, ra)
.globl _mcount
_mcount:
b ftrace_stub
#ifdef CONFIG_32BIT
addiu sp,sp,8
#else
nop
#endif
/* When tracing is activated, it calls ftrace_caller+8 (aka here) */
lw t1, function_trace_stop
bnez t1, ftrace_stub
nop
MCOUNT_SAVE_REGS
#ifdef KBUILD_MCOUNT_RA_ADDRESS
PTR_S MCOUNT_RA_ADDRESS_REG, PT_R12(sp)
#endif
move a0, ra /* arg1: self return address */
.globl ftrace_call
ftrace_call:
nop /* a placeholder for the call to a real tracing function */
move a1, AT /* arg2: parent's return address */
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
.globl ftrace_graph_call
ftrace_graph_call:
nop
nop
#endif
MCOUNT_RESTORE_REGS
.globl ftrace_stub
ftrace_stub:
RETURN_BACK
END(ftrace_caller)
#else /* ! CONFIG_DYNAMIC_FTRACE */
NESTED(_mcount, PT_SIZE, ra)
lw t1, function_trace_stop
bnez t1, ftrace_stub
nop
PTR_LA t1, ftrace_stub
PTR_L t2, ftrace_trace_function /* Prepare t2 for (1) */
bne t1, t2, static_trace
nop
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
PTR_L t3, ftrace_graph_return
bne t1, t3, ftrace_graph_caller
nop
PTR_LA t1, ftrace_graph_entry_stub
PTR_L t3, ftrace_graph_entry
bne t1, t3, ftrace_graph_caller
nop
#endif
b ftrace_stub
nop
static_trace:
MCOUNT_SAVE_REGS
move a0, ra /* arg1: self return address */
jalr t2 /* (1) call *ftrace_trace_function */
move a1, AT /* arg2: parent's return address */
MCOUNT_RESTORE_REGS
.globl ftrace_stub
ftrace_stub:
RETURN_BACK
END(_mcount)
#endif /* ! CONFIG_DYNAMIC_FTRACE */
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
NESTED(ftrace_graph_caller, PT_SIZE, ra)
#ifndef CONFIG_DYNAMIC_FTRACE
MCOUNT_SAVE_REGS
#endif
/* arg1: Get the location of the parent's return address */
#ifdef KBUILD_MCOUNT_RA_ADDRESS
#ifdef CONFIG_DYNAMIC_FTRACE
PTR_L a0, PT_R12(sp)
#else
move a0, MCOUNT_RA_ADDRESS_REG
#endif
bnez a0, 1f /* non-leaf func: stored in MCOUNT_RA_ADDRESS_REG */
nop
#endif
PTR_LA a0, PT_R1(sp) /* leaf func: the location in current stack */
1:
/* arg2: Get self return address */
#ifdef CONFIG_DYNAMIC_FTRACE
PTR_L a1, PT_R31(sp)
#else
move a1, ra
#endif
/* arg3: Get frame pointer of current stack */
#ifdef CONFIG_64BIT
PTR_LA a2, PT_SIZE(sp)
#else
PTR_LA a2, (PT_SIZE+8)(sp)
#endif
jal prepare_ftrace_return
nop
MCOUNT_RESTORE_REGS
RETURN_BACK
END(ftrace_graph_caller)
.align 2
.globl return_to_handler
return_to_handler:
PTR_SUBU sp, PT_SIZE
PTR_S v0, PT_R2(sp)
jal ftrace_return_to_handler
PTR_S v1, PT_R3(sp)
/* restore the real parent address: v0 -> ra */
move ra, v0
PTR_L v0, PT_R2(sp)
PTR_L v1, PT_R3(sp)
jr ra
PTR_ADDIU sp, PT_SIZE
#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
.set at
.set reorder
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