Commit 1c873be7 authored by Mike Frysinger's avatar Mike Frysinger
Browse files

Blackfin: initial support for ftrace 



Just the basic ftrace support here -- mcount and the ftrace stub.

Signed-off-by: default avatarMike Frysinger <vapier@gentoo.org>
parent 6fa68e7a

arch/blackfin/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -19,6 +19,7 @@ config RWSEM_XCHGADD_ALGORITHM 


config BLACKFIN

	def_bool y

	select HAVE_FUNCTION_TRACER

	select HAVE_IDE

	select HAVE_KERNEL_GZIP

	select HAVE_KERNEL_BZIP2

arch/blackfin/include/asm/ftrace.h

+13 −1
Original line number Diff line number Diff line 
/* empty */
 
/*

 * Blackfin ftrace code

 *

 * Copyright 2009 Analog Devices Inc.

 * Licensed under the GPL-2 or later.

 */



#ifndef __ASM_BFIN_FTRACE_H__

#define __ASM_BFIN_FTRACE_H__



#define MCOUNT_INSN_SIZE	8 /* sizeof mcount call: LINK + CALL */



#endif

arch/blackfin/kernel/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -15,6 +15,7 @@ else 
    obj-y += time.o

endif



obj-$(CONFIG_FUNCTION_TRACER)        += ftrace-entry.o

obj-$(CONFIG_IPIPE)                  += ipipe.o

obj-$(CONFIG_IPIPE_TRACE_MCOUNT)     += mcount.o

obj-$(CONFIG_BFIN_GPTIMERS)          += gptimers.o

arch/blackfin/kernel/bfin_ksyms.c

+5 −0
Original line number Diff line number Diff line
@@ -103,3 +103,8 @@ EXPORT_SYMBOL(__raw_smp_mark_barrier_asm); 
EXPORT_SYMBOL(__raw_smp_check_barrier_asm);

#endif

#endif



#ifdef CONFIG_FUNCTION_TRACER

extern void _mcount(void);

EXPORT_SYMBOL(_mcount);

#endif

arch/blackfin/kernel/ftrace-entry.S

0 → 100644
+72 −0
Original line number Diff line number Diff line 
/*

 * mcount and friends -- ftrace stuff

 *

 * Copyright (C) 2009 Analog Devices Inc.

 * Licensed under the GPL-2 or later.

 */



#include <linux/linkage.h>

#include <asm/ftrace.h>



.text



/* GCC will have called us before setting up the function prologue, so we

 * can clobber the normal scratch registers, but we need to make sure to

 * save/restore the registers used for argument passing (R0-R2) in case

 * the profiled function is using them.  With data registers, R3 is the

 * only one we can blow away.  With pointer registers, we have P0-P2.

 *

 * Upon entry, the RETS will point to the top of the current profiled

 * function.  And since GCC setup the frame for us, the previous function

 * will be waiting there.  mmmm pie.

 */

ENTRY(__mcount)

	/* save third function arg early so we can do testing below */

	[--sp] = r2;



	/* load the function pointer to the tracer */

	p0.l = _ftrace_trace_function;

	p0.h = _ftrace_trace_function;

	r3 = [p0];



	/* optional micro optimization: don't call the stub tracer */

	r2.l = _ftrace_stub;

	r2.h = _ftrace_stub;

	cc = r2 == r3;

	if ! cc jump .Ldo_trace;



	r2 = [sp++];

	rts;



.Ldo_trace:



	/* save first/second function arg and the return register */

	[--sp] = r0;

	[--sp] = r1;

	[--sp] = rets;



	/* setup the tracer function */

	p0 = r3;



	/* tracer(ulong frompc, ulong selfpc):

	 *  frompc: the pc that did the call to ...

	 *  selfpc: ... this location

	 * the selfpc itself will need adjusting for the mcount call

	 */

	r1 = rets;

	r0 = [fp + 4];

	r1 += -MCOUNT_INSN_SIZE;



	/* call the tracer */

	call (p0);



	/* restore state and get out of dodge */

	rets = [sp++];

	r1 = [sp++];

	r0 = [sp++];

	r2 = [sp++];



.globl _ftrace_stub

_ftrace_stub:

	rts;

ENDPROC(__mcount)