linux/arch/tile/kernel/mcount_64.S
Tony Lu 437d3e124d tile: ftrace: fix function_graph tracer issues
- Add support for ARCH_SUPPORTS_FTRACE_OPS
- Replace the instruction in ftrace_call with the bundle {move r10, lr;
jal ftrace_stub}, so that the lr contains the right value after returning
from ftrace_stub.  An alternative fix might be to leave the instruction
in ftrace_call alone when it is being updated with ftrace_stub.

Signed-off-by: Tony Lu <zlu@ezchip.com>
Signed-off-by: Chris Metcalf <cmetcalf@ezchip.com>
2015-04-17 14:01:38 -04:00

212 lines
4.7 KiB
ArmAsm

/*
* Copyright 2012 Tilera Corporation. All Rights Reserved.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation, version 2.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
* NON INFRINGEMENT. See the GNU General Public License for
* more details.
*
* TILE-Gx specific __mcount support
*/
#include <linux/linkage.h>
#include <asm/ftrace.h>
#define REGSIZE 8
.text
.global __mcount
.macro MCOUNT_SAVE_REGS
addli sp, sp, -REGSIZE
{
st sp, lr
addli r29, sp, - (12 * REGSIZE)
}
{
addli sp, sp, - (13 * REGSIZE)
st r29, sp
}
addli r29, r29, REGSIZE
{ st r29, r0; addli r29, r29, REGSIZE }
{ st r29, r1; addli r29, r29, REGSIZE }
{ st r29, r2; addli r29, r29, REGSIZE }
{ st r29, r3; addli r29, r29, REGSIZE }
{ st r29, r4; addli r29, r29, REGSIZE }
{ st r29, r5; addli r29, r29, REGSIZE }
{ st r29, r6; addli r29, r29, REGSIZE }
{ st r29, r7; addli r29, r29, REGSIZE }
{ st r29, r8; addli r29, r29, REGSIZE }
{ st r29, r9; addli r29, r29, REGSIZE }
{ st r29, r10; addli r29, r29, REGSIZE }
.endm
.macro MCOUNT_RESTORE_REGS
addli r29, sp, (2 * REGSIZE)
{ ld r0, r29; addli r29, r29, REGSIZE }
{ ld r1, r29; addli r29, r29, REGSIZE }
{ ld r2, r29; addli r29, r29, REGSIZE }
{ ld r3, r29; addli r29, r29, REGSIZE }
{ ld r4, r29; addli r29, r29, REGSIZE }
{ ld r5, r29; addli r29, r29, REGSIZE }
{ ld r6, r29; addli r29, r29, REGSIZE }
{ ld r7, r29; addli r29, r29, REGSIZE }
{ ld r8, r29; addli r29, r29, REGSIZE }
{ ld r9, r29; addli r29, r29, REGSIZE }
{ ld r10, r29; addli lr, sp, (13 * REGSIZE) }
{ ld lr, lr; addli sp, sp, (14 * REGSIZE) }
.endm
.macro RETURN_BACK
{ move r12, lr; move lr, r10 }
jrp r12
.endm
#ifdef CONFIG_DYNAMIC_FTRACE
.align 64
STD_ENTRY(__mcount)
__mcount:
j ftrace_stub
STD_ENDPROC(__mcount)
.align 64
STD_ENTRY(ftrace_caller)
MCOUNT_SAVE_REGS
/* arg1: self return address */
/* arg2: parent's return address */
/* arg3: ftrace_ops */
/* arg4: regs (but make it NULL) */
{ move r0, lr; moveli r2, hw2_last(function_trace_op) }
{ move r1, r10; shl16insli r2, r2, hw1(function_trace_op) }
{ movei r3, 0; shl16insli r2, r2, hw0(function_trace_op) }
ld r2,r2
.global ftrace_call
ftrace_call:
/*
* a placeholder for the call to a real tracing function, i.e.
* ftrace_trace_function()
*/
nop
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
.global ftrace_graph_call
ftrace_graph_call:
/*
* a placeholder for the call to a real tracing function, i.e.
* ftrace_graph_caller()
*/
nop
#endif
MCOUNT_RESTORE_REGS
.global ftrace_stub
ftrace_stub:
RETURN_BACK
STD_ENDPROC(ftrace_caller)
#else /* ! CONFIG_DYNAMIC_FTRACE */
.align 64
STD_ENTRY(__mcount)
{
moveli r11, hw2_last(ftrace_trace_function)
moveli r13, hw2_last(ftrace_stub)
}
{
shl16insli r11, r11, hw1(ftrace_trace_function)
shl16insli r13, r13, hw1(ftrace_stub)
}
{
shl16insli r11, r11, hw0(ftrace_trace_function)
shl16insli r13, r13, hw0(ftrace_stub)
}
ld r11, r11
sub r14, r13, r11
bnez r14, static_trace
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
moveli r15, hw2_last(ftrace_graph_return)
shl16insli r15, r15, hw1(ftrace_graph_return)
shl16insli r15, r15, hw0(ftrace_graph_return)
ld r15, r15
sub r15, r15, r13
bnez r15, ftrace_graph_caller
{
moveli r16, hw2_last(ftrace_graph_entry)
moveli r17, hw2_last(ftrace_graph_entry_stub)
}
{
shl16insli r16, r16, hw1(ftrace_graph_entry)
shl16insli r17, r17, hw1(ftrace_graph_entry_stub)
}
{
shl16insli r16, r16, hw0(ftrace_graph_entry)
shl16insli r17, r17, hw0(ftrace_graph_entry_stub)
}
ld r16, r16
sub r17, r16, r17
bnez r17, ftrace_graph_caller
#endif
RETURN_BACK
static_trace:
MCOUNT_SAVE_REGS
/* arg1: self return address */
/* arg2: parent's return address */
{ move r0, lr; move r1, r10 }
/* call ftrace_trace_function() */
jalr r11
MCOUNT_RESTORE_REGS
.global ftrace_stub
ftrace_stub:
RETURN_BACK
STD_ENDPROC(__mcount)
#endif /* ! CONFIG_DYNAMIC_FTRACE */
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
STD_ENTRY(ftrace_graph_caller)
ftrace_graph_caller:
#ifndef CONFIG_DYNAMIC_FTRACE
MCOUNT_SAVE_REGS
#endif
/* arg1: Get the location of the parent's return address */
addi r0, sp, 12 * REGSIZE
/* arg2: Get self return address */
move r1, lr
jal prepare_ftrace_return
MCOUNT_RESTORE_REGS
RETURN_BACK
STD_ENDPROC(ftrace_graph_caller)
.global return_to_handler
return_to_handler:
MCOUNT_SAVE_REGS
jal ftrace_return_to_handler
/* restore the real parent address */
move r11, r0
MCOUNT_RESTORE_REGS
jr r11
#endif /* CONFIG_FUNCTION_GRAPH_TRACER */