/*
* 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
* Author: Wu Zhangjin <wuzj@lemote.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
#ifdef CONFIG_64BIT
PTR_ADDIU sp, PT_SIZE
#else
PTR_ADDIU sp, (PT_SIZE + 8)
#endif
.endm
.macro RETURN_BACK
jr ra
move ra, AT
.endm
#ifdef CONFIG_DYNAMIC_FTRACE
NESTED(ftrace_caller, PT_SIZE, ra)
.globl _mcount
_mcount:
b ftrace_stub
nop
lw t1, function_trace_stop
bnez t1, ftrace_stub
nop
MCOUNT_SAVE_REGS
#ifdef KBUILD_MCOUNT_RA_ADDRESS
PTR_S t0, PT_R12(sp) /* t0 saved the location of the return address(at) by -mmcount-ra-address */
#endif
move a0, ra /* arg1: next ip, selfaddr */
.globl ftrace_call
ftrace_call:
nop /* a placeholder for the call to a real tracing function */
move a1, AT /* arg2: the caller's next ip, parent */
#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: next ip, selfaddr */
jalr t2 /* (1) call *ftrace_trace_function */
move a1, AT /* arg2: the caller's next ip, parent */
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)
#ifdef CONFIG_DYNAMIC_FTRACE
PTR_L a1, PT_R31(sp) /* load the original ra from the stack */
#ifdef KBUILD_MCOUNT_RA_ADDRESS
PTR_L t0, PT_R12(sp) /* load the original t0 from the stack */
#endif
#else
MCOUNT_SAVE_REGS
move a1, ra /* arg2: next ip, selfaddr */
#endif
#ifdef KBUILD_MCOUNT_RA_ADDRESS
bnez t0, 1f /* non-leaf func: t0 saved the location of the return address */
nop
PTR_LA t0, PT_R1(sp) /* leaf func: get the location of at(old ra) from our own stack */
1: move a0, t0 /* arg1: the location of the return address */
#else
PTR_LA a0, PT_R1(sp) /* arg1: &AT -> a0 */
#endif
jal prepare_ftrace_return
#ifdef CONFIG_FRAME_POINTER
move a2, fp /* arg3: frame pointer */
#else
#ifdef CONFIG_64BIT
PTR_LA a2, PT_SIZE(sp)
#else
PTR_LA a2, (PT_SIZE+8)(sp)
#endif
#endif
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
