Commit a61fd5e3 authored by Tony Lu's avatar Tony Lu Committed by Chris Metcalf

tile: support ftrace on tilegx

This commit adds support for static ftrace, graph function support,
and dynamic tracer support.
Signed-off-by: default avatarTony Lu <zlu@tilera.com>
Signed-off-by: default avatarChris Metcalf <cmetcalf@tilera.com>
parent 9ae09838
......@@ -119,7 +119,12 @@ config HVC_TILE
def_bool y
config TILEGX
bool "Building with TILE-Gx (64-bit) compiler and toolchain"
bool "Building for TILE-Gx (64-bit) processor"
select HAVE_FUNCTION_TRACER
select HAVE_FUNCTION_TRACE_MCOUNT_TEST
select HAVE_FUNCTION_GRAPH_TRACER
select HAVE_DYNAMIC_FTRACE
select HAVE_FTRACE_MCOUNT_RECORD
config TILEPRO
def_bool !TILEGX
......
......@@ -15,6 +15,26 @@
#ifndef _ASM_TILE_FTRACE_H
#define _ASM_TILE_FTRACE_H
/* empty */
#ifdef CONFIG_FUNCTION_TRACER
#define MCOUNT_ADDR ((unsigned long)(__mcount))
#define MCOUNT_INSN_SIZE 8 /* sizeof mcount call */
#ifndef __ASSEMBLY__
extern void __mcount(void);
#ifdef CONFIG_DYNAMIC_FTRACE
static inline unsigned long ftrace_call_adjust(unsigned long addr)
{
return addr;
}
struct dyn_arch_ftrace {
};
#endif /* CONFIG_DYNAMIC_FTRACE */
#endif /* __ASSEMBLY__ */
#endif /* CONFIG_FUNCTION_TRACER */
#endif /* _ASM_TILE_FTRACE_H */
......@@ -9,6 +9,11 @@ obj-y := backtrace.o entry.o hvglue.o irq.o messaging.o \
sysfs.o time.o traps.o unaligned.o vdso.o \
intvec_$(BITS).o regs_$(BITS).o tile-desc_$(BITS).o
ifdef CONFIG_FUNCTION_TRACER
CFLAGS_REMOVE_ftrace.o = -pg
CFLAGS_REMOVE_early_printk.o = -pg
endif
obj-$(CONFIG_HARDWALL) += hardwall.o
obj-$(CONFIG_COMPAT) += compat.o compat_signal.o
obj-$(CONFIG_SMP) += smpboot.o smp.o tlb.o
......@@ -22,5 +27,6 @@ obj-$(CONFIG_PCI) += pci.o
endif
obj-$(CONFIG_TILE_USB) += usb.o
obj-$(CONFIG_TILE_HVGLUE_TRACE) += hvglue_trace.o
obj-$(CONFIG_FUNCTION_TRACER) += ftrace.o mcount_64.o
obj-y += vdso/
/*
* 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 ftrace support
*/
#include <linux/ftrace.h>
#include <linux/uaccess.h>
#include <asm/cacheflush.h>
#include <asm/ftrace.h>
#include <asm/sections.h>
#include <arch/opcode.h>
#ifdef CONFIG_DYNAMIC_FTRACE
static inline tilegx_bundle_bits NOP(void)
{
return create_UnaryOpcodeExtension_X0(FNOP_UNARY_OPCODE_X0) |
create_RRROpcodeExtension_X0(UNARY_RRR_0_OPCODE_X0) |
create_Opcode_X0(RRR_0_OPCODE_X0) |
create_UnaryOpcodeExtension_X1(NOP_UNARY_OPCODE_X1) |
create_RRROpcodeExtension_X1(UNARY_RRR_0_OPCODE_X1) |
create_Opcode_X1(RRR_0_OPCODE_X1);
}
static int machine_stopped __read_mostly;
int ftrace_arch_code_modify_prepare(void)
{
machine_stopped = 1;
return 0;
}
int ftrace_arch_code_modify_post_process(void)
{
flush_icache_range(0, CHIP_L1I_CACHE_SIZE());
machine_stopped = 0;
return 0;
}
/*
* Put { move r10, lr; jal ftrace_caller } in a bundle, this lets dynamic
* tracer just add one cycle overhead to every kernel function when disabled.
*/
static unsigned long ftrace_gen_branch(unsigned long pc, unsigned long addr,
bool link)
{
tilegx_bundle_bits opcode_x0, opcode_x1;
long pcrel_by_instr = (addr - pc) >> TILEGX_LOG2_BUNDLE_SIZE_IN_BYTES;
if (link) {
/* opcode: jal addr */
opcode_x1 =
create_Opcode_X1(JUMP_OPCODE_X1) |
create_JumpOpcodeExtension_X1(JAL_JUMP_OPCODE_X1) |
create_JumpOff_X1(pcrel_by_instr);
} else {
/* opcode: j addr */
opcode_x1 =
create_Opcode_X1(JUMP_OPCODE_X1) |
create_JumpOpcodeExtension_X1(J_JUMP_OPCODE_X1) |
create_JumpOff_X1(pcrel_by_instr);
}
if (addr == FTRACE_ADDR) {
/* opcode: or r10, lr, zero */
opcode_x0 =
create_Dest_X0(10) |
create_SrcA_X0(TREG_LR) |
create_SrcB_X0(TREG_ZERO) |
create_RRROpcodeExtension_X0(OR_RRR_0_OPCODE_X0) |
create_Opcode_X0(RRR_0_OPCODE_X0);
} else {
/* opcode: fnop */
opcode_x0 =
create_UnaryOpcodeExtension_X0(FNOP_UNARY_OPCODE_X0) |
create_RRROpcodeExtension_X0(UNARY_RRR_0_OPCODE_X0) |
create_Opcode_X0(RRR_0_OPCODE_X0);
}
return opcode_x1 | opcode_x0;
}
static unsigned long ftrace_nop_replace(struct dyn_ftrace *rec)
{
return NOP();
}
static unsigned long ftrace_call_replace(unsigned long pc, unsigned long addr)
{
return ftrace_gen_branch(pc, addr, true);
}
static int ftrace_modify_code(unsigned long pc, unsigned long old,
unsigned long new)
{
unsigned long pc_wr;
/* Check if the address is in kernel text space and module space. */
if (!kernel_text_address(pc))
return -EINVAL;
/* Operate on writable kernel text mapping. */
pc_wr = pc - MEM_SV_START + PAGE_OFFSET;
if (probe_kernel_write((void *)pc_wr, &new, MCOUNT_INSN_SIZE))
return -EPERM;
smp_wmb();
if (!machine_stopped && num_online_cpus() > 1)
flush_icache_range(pc, pc + MCOUNT_INSN_SIZE);
return 0;
}
int ftrace_update_ftrace_func(ftrace_func_t func)
{
unsigned long pc, old;
unsigned long new;
int ret;
pc = (unsigned long)&ftrace_call;
memcpy(&old, &ftrace_call, MCOUNT_INSN_SIZE);
new = ftrace_call_replace(pc, (unsigned long)func);
ret = ftrace_modify_code(pc, old, new);
return ret;
}
int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
{
unsigned long new, old;
unsigned long ip = rec->ip;
old = ftrace_nop_replace(rec);
new = ftrace_call_replace(ip, addr);
return ftrace_modify_code(rec->ip, old, new);
}
int ftrace_make_nop(struct module *mod,
struct dyn_ftrace *rec, unsigned long addr)
{
unsigned long ip = rec->ip;
unsigned long old;
unsigned long new;
int ret;
old = ftrace_call_replace(ip, addr);
new = ftrace_nop_replace(rec);
ret = ftrace_modify_code(ip, old, new);
return ret;
}
int __init ftrace_dyn_arch_init(void *data)
{
*(unsigned long *)data = 0;
return 0;
}
#endif /* CONFIG_DYNAMIC_FTRACE */
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr,
unsigned long frame_pointer)
{
unsigned long return_hooker = (unsigned long) &return_to_handler;
struct ftrace_graph_ent trace;
unsigned long old;
int err;
if (unlikely(atomic_read(&current->tracing_graph_pause)))
return;
old = *parent;
*parent = return_hooker;
err = ftrace_push_return_trace(old, self_addr, &trace.depth,
frame_pointer);
if (err == -EBUSY) {
*parent = old;
return;
}
trace.func = self_addr;
/* Only trace if the calling function expects to */
if (!ftrace_graph_entry(&trace)) {
current->curr_ret_stack--;
*parent = old;
}
}
#ifdef CONFIG_DYNAMIC_FTRACE
extern unsigned long ftrace_graph_call;
static int __ftrace_modify_caller(unsigned long *callsite,
void (*func) (void), bool enable)
{
unsigned long caller_fn = (unsigned long) func;
unsigned long pc = (unsigned long) callsite;
unsigned long branch = ftrace_gen_branch(pc, caller_fn, false);
unsigned long nop = NOP();
unsigned long old = enable ? nop : branch;
unsigned long new = enable ? branch : nop;
return ftrace_modify_code(pc, old, new);
}
static int ftrace_modify_graph_caller(bool enable)
{
int ret;
ret = __ftrace_modify_caller(&ftrace_graph_call,
ftrace_graph_caller,
enable);
return ret;
}
int ftrace_enable_ftrace_graph_caller(void)
{
return ftrace_modify_graph_caller(true);
}
int ftrace_disable_ftrace_graph_caller(void)
{
return ftrace_modify_graph_caller(false);
}
#endif /* CONFIG_DYNAMIC_FTRACE */
#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
/*
* 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)
moveli r11, hw2_last(function_trace_stop)
{ shl16insli r11, r11, hw1(function_trace_stop); move r12, lr }
{ shl16insli r11, r11, hw0(function_trace_stop); move lr, r10 }
ld r11, r11
beqz r11, 1f
jrp r12
1:
{ move r10, lr; move lr, r12 }
MCOUNT_SAVE_REGS
/* arg1: self return address */
/* arg2: parent's return address */
{ move r0, lr; move r1, r10 }
.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(function_trace_stop)
{ shl16insli r11, r11, hw1(function_trace_stop); move r12, lr }
{ shl16insli r11, r11, hw0(function_trace_stop); move lr, r10 }
ld r11, r11
beqz r11, 1f
jrp r12
1:
{ move r10, lr; move lr, r12 }
{
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 */
......@@ -43,6 +43,7 @@ SECTIONS
HEAD_TEXT
SCHED_TEXT
LOCK_TEXT
IRQENTRY_TEXT
__fix_text_end = .; /* tile-cpack won't rearrange before this */
TEXT_TEXT
*(.text.*)
......
......@@ -33,6 +33,12 @@ EXPORT_SYMBOL(dump_stack);
/* arch/tile/kernel/head.S */
EXPORT_SYMBOL(empty_zero_page);
#ifdef CONFIG_FUNCTION_TRACER
/* arch/tile/kernel/mcount_64.S */
#include <asm/ftrace.h>
EXPORT_SYMBOL(__mcount);
#endif /* CONFIG_FUNCTION_TRACER */
/* arch/tile/lib/, various memcpy files */
EXPORT_SYMBOL(memcpy);
EXPORT_SYMBOL(__copy_to_user_inatomic);
......
......@@ -364,6 +364,10 @@ if ($arch eq "x86_64") {
} elsif ($arch eq "blackfin") {
$mcount_regex = "^\\s*([0-9a-fA-F]+):.*\\s__mcount\$";
$mcount_adjust = -4;
} elsif ($arch eq "tilegx") {
$mcount_regex = "^\\s*([0-9a-fA-F]+):.*\\s__mcount\$";
$type = ".quad";
$alignment = 8;
} else {
die "Arch $arch is not supported with CONFIG_FTRACE_MCOUNT_RECORD";
}
......
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