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-rw-r--r--arch/mips/kernel/mcount.S189
1 files changed, 189 insertions, 0 deletions
diff --git a/arch/mips/kernel/mcount.S b/arch/mips/kernel/mcount.S
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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
+ * 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