On Wed, 2009-10-21 at 22:34 +0800, Wu Zhangjin wrote: > +++ b/arch/mips/kernel/mcount.S > @@ -0,0 +1,94 @@ > +/* > + * the mips-specific _mcount implementation > + * > + * 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 DSLab, Lanzhou University, China > + * Author: Wu Zhangjin <wuzj@xxxxxxxxxx> > + */ > + > +#include <asm/regdef.h> > +#include <asm/stackframe.h> > +#include <asm/ftrace.h> > + > + .text > + .set noreorder > + .set noat > + > + /* since there is a "addiu sp,sp,-8" before "jal _mcount" in 32bit */ > + .macro RESTORE_SP_FOR_32BIT > +#ifdef CONFIG_32BIT > + PTR_ADDIU sp, 8 > +#endif > + .endm > + > + .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 MCOUNT_SET_ARGS > + move a0, ra /* arg1: next ip, selfaddr */ > + move a1, AT /* arg2: the caller's next ip, parent */ > + PTR_SUBU a0, MCOUNT_INSN_SIZE > + .endm > + > + .macro RETURN_BACK > + jr ra > + move ra, AT > + .endm > + > +NESTED(_mcount, PT_SIZE, ra) > + RESTORE_SP_FOR_32BIT > + PTR_LA t0, ftrace_stub > + PTR_L t1, ftrace_trace_function /* please don't use t1 later, safe? */ Is t0 and t1 safe for mcount to use? Remember, mcount does not follow the dynamics of C function ABI. -- Steve > + bne t0, t1, static_trace > + nop > + > + j ftrace_stub > + nop > + > +static_trace: > + MCOUNT_SAVE_REGS > + > + MCOUNT_SET_ARGS /* call *ftrace_trace_function */ > + jalr t1 > + nop > + > + MCOUNT_RESTORE_REGS > + .globl ftrace_stub > +ftrace_stub: > + RETURN_BACK > + END(_mcount) > +
