2 * MIPS specific _mcount support
4 * This file is subject to the terms and conditions of the GNU General Public
5 * License. See the file "COPYING" in the main directory of this archive for
8 * Copyright (C) 2009 Lemote Inc. & DSLab, Lanzhou University, China
9 * Author: Wu Zhangjin <wuzhangjin@gmail.com>
12 #include <asm/regdef.h>
13 #include <asm/stackframe.h>
14 #include <asm/ftrace.h>
20 .macro MCOUNT_SAVE_REGS
36 .macro MCOUNT_RESTORE_REGS
50 PTR_ADDIU sp, (PT_SIZE + 8)
59 #ifdef CONFIG_DYNAMIC_FTRACE
61 NESTED(ftrace_caller, PT_SIZE, ra)
66 lw t1, function_trace_stop
71 #ifdef KBUILD_MCOUNT_RA_ADDRESS
72 PTR_S t0, PT_R12(sp) /* t0 saved the location of the return address(at) by -mmcount-ra-address */
75 move a0, ra /* arg1: next ip, selfaddr */
78 nop /* a placeholder for the call to a real tracing function */
79 move a1, AT /* arg2: the caller's next ip, parent */
81 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
82 .globl ftrace_graph_call
94 #else /* ! CONFIG_DYNAMIC_FTRACE */
96 NESTED(_mcount, PT_SIZE, ra)
97 lw t1, function_trace_stop
100 PTR_LA t1, ftrace_stub
101 PTR_L t2, ftrace_trace_function /* Prepare t2 for (1) */
102 bne t1, t2, static_trace
105 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
106 PTR_L t3, ftrace_graph_return
107 bne t1, t3, ftrace_graph_caller
109 PTR_LA t1, ftrace_graph_entry_stub
110 PTR_L t3, ftrace_graph_entry
111 bne t1, t3, ftrace_graph_caller
120 move a0, ra /* arg1: next ip, selfaddr */
121 jalr t2 /* (1) call *ftrace_trace_function */
122 move a1, AT /* arg2: the caller's next ip, parent */
130 #endif /* ! CONFIG_DYNAMIC_FTRACE */
132 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
134 NESTED(ftrace_graph_caller, PT_SIZE, ra)
135 #ifdef CONFIG_DYNAMIC_FTRACE
136 PTR_L a1, PT_R31(sp) /* load the original ra from the stack */
137 #ifdef KBUILD_MCOUNT_RA_ADDRESS
138 PTR_L t0, PT_R12(sp) /* load the original t0 from the stack */
142 move a1, ra /* arg2: next ip, selfaddr */
145 #ifdef KBUILD_MCOUNT_RA_ADDRESS
146 bnez t0, 1f /* non-leaf func: t0 saved the location of the return address */
148 PTR_LA t0, PT_R1(sp) /* leaf func: get the location of at(old ra) from our own stack */
149 1: move a0, t0 /* arg1: the location of the return address */
151 PTR_LA a0, PT_R1(sp) /* arg1: &AT -> a0 */
153 jal prepare_ftrace_return
154 #ifdef CONFIG_FRAME_POINTER
155 move a2, fp /* arg3: frame pointer */
158 PTR_LA a2, PT_SIZE(sp)
160 PTR_LA a2, (PT_SIZE+8)(sp)
166 END(ftrace_graph_caller)
169 .globl return_to_handler
174 jal ftrace_return_to_handler
177 /* restore the real parent address: v0 -> ra */
183 PTR_ADDIU sp, PT_SIZE
184 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */