1 files changed, 189 insertions, 0 deletions

diff --git a/arch/mips/kernel/mcount.S b/arch/mips/kernel/mcount.S
new file mode 100644
index 000000000000..0a9cfdb271dd
--- /dev/null
+++ b/arch/mips/kernel/mcount.S
@@ -0,0 +1,189 @@
+/*
+ * 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