/* * 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 <linux/export.h>#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:EXPORT_SYMBOL(_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) */	MCOUNT_SAVE_REGS#ifdef KBUILD_MCOUNT_RA_ADDRESS	PTR_S	MCOUNT_RA_ADDRESS_REG, PT_R12(sp)#endif 	PTR_SUBU a0, ra, 8	/* arg1: self address */	PTR_LA   t1, _stext	sltu     t2, a0, t1	/* t2 = (a0 < _stext) */	PTR_LA   t1, _etext	sltu     t3, t1, a0	/* t3 = (a0 > _etext) */	or       t1, t2, t3	beqz     t1, ftrace_call	 nop#if defined(KBUILD_MCOUNT_RA_ADDRESS) && defined(CONFIG_32BIT)	PTR_SUBU a0, a0, 16	/* arg1: adjust to module's recorded callsite */#else	PTR_SUBU a0, a0, 12#endif 	.globl ftrace_callftrace_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_callftrace_graph_call:	nop	 nop#endif 	MCOUNT_RESTORE_REGS	.globl ftrace_stubftrace_stub:	RETURN_BACK	END(ftrace_caller) #else	/* ! CONFIG_DYNAMIC_FTRACE */ NESTED(_mcount, PT_SIZE, ra)EXPORT_SYMBOL(_mcount)	PTR_LA	t1, ftrace_stub	PTR_L	t2, ftrace_trace_function /* Prepare t2 for (1) */	beq	t1, t2, fgraph_trace	 nop 	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 fgraph_trace:#ifdef	CONFIG_FUNCTION_GRAPH_TRACER	PTR_LA	t1, ftrace_stub	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 #ifdef CONFIG_32BIT	addiu sp, sp, 8#endif 	.globl ftrace_stubftrace_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#ifndef CONFIG_DYNAMIC_FTRACE#ifdef CONFIG_32BIT	addiu sp, sp, 8#endif#endif	RETURN_BACK	END(ftrace_graph_caller) 	.align	2	.globl	return_to_handlerreturn_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