diff options
Diffstat (limited to 'arch/mips/kernel/mcount.S')
| -rw-r--r-- | arch/mips/kernel/mcount.S | 220 |
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 0000000000..fcec579f64 --- /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 <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_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) +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_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 |