Initial import

1 files changed, 220 insertions, 0 deletions

diff --git a/arch/mips/kernel/mcount.S b/arch/mips/kernel/mcount.S
new file mode 100644
index 000000000..2f7c73477
--- /dev/null
+++ b/arch/mips/kernel/mcount.S
@@ -0,0 +1,220 @@
+/*
+ * 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) */
+	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_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)
+	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
+#ifdef CONFIG_32BIT
+	 addiu sp, sp, 8
+#else
+	 nop
+#endif
+
+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
+#ifdef CONFIG_32BIT
+	addiu sp, sp, 8
+#endif
+	.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
+#ifndef CONFIG_DYNAMIC_FTRACE
+#ifdef CONFIG_32BIT
+	addiu sp, sp, 8
+#endif
+#endif
+	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