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metag: ftrace support

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Add ftrace support for metag.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
This commit is contained in:
James Hogan 2012-10-05 16:27:31 +01:00
parent 903b20ad68
commit 00512bdd45
7 changed files with 248 additions and 1 deletions
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5
arch/metag/Kconfig
View file

@ -12,7 +12,12 @@ config METAG
select GENERIC_SMP_IDLE_THREAD
select HAVE_64BIT_ALIGNED_ACCESS
select HAVE_ARCH_TRACEHOOK
select HAVE_C_RECORDMCOUNT
select HAVE_DEBUG_KMEMLEAK
select HAVE_DYNAMIC_FTRACE
select HAVE_FTRACE_MCOUNT_RECORD
select HAVE_FUNCTION_TRACER
select HAVE_FUNCTION_TRACE_MCOUNT_TEST
select HAVE_GENERIC_HARDIRQS
select HAVE_IRQ_WORK
select HAVE_KERNEL_BZIP2

1
arch/metag/include/asm/Kbuild
View file

@ -11,7 +11,6 @@ generic-y += errno.h
generic-y += exec.h
generic-y += fb.h
generic-y += fcntl.h
generic-y += ftrace.h
generic-y += futex.h
generic-y += hardirq.h
generic-y += hw_irq.h

23
arch/metag/include/asm/ftrace.h Normal file
View file

@ -0,0 +1,23 @@
#ifndef _ASM_METAG_FTRACE
#define _ASM_METAG_FTRACE
#ifdef CONFIG_FUNCTION_TRACER
#define MCOUNT_INSN_SIZE 8 /* sizeof mcount call */
#ifndef __ASSEMBLY__
extern void mcount_wrapper(void);
#define MCOUNT_ADDR ((long)(mcount_wrapper))
static inline unsigned long ftrace_call_adjust(unsigned long addr)
{
return addr;
}
struct dyn_arch_ftrace {
/* No extra data needed on metag */
};
#endif /* __ASSEMBLY__ */
#endif /* CONFIG_FUNCTION_TRACER */
#endif /* _ASM_METAG_FTRACE */

126
arch/metag/kernel/ftrace.c Normal file
View file

@ -0,0 +1,126 @@
/*
* Copyright (C) 2008 Imagination Technologies Ltd.
* Licensed under the GPL
*
* Dynamic ftrace support.
*/
#include <linux/ftrace.h>
#include <linux/io.h>
#include <linux/uaccess.h>
#include <asm/cacheflush.h>
#define D04_MOVT_TEMPLATE 0x02200005
#define D04_CALL_TEMPLATE 0xAC200005
#define D1RTP_MOVT_TEMPLATE 0x03200005
#define D1RTP_CALL_TEMPLATE 0xAC200006
static const unsigned long NOP[2] = {0xa0fffffe, 0xa0fffffe};
static unsigned long movt_and_call_insn[2];
static unsigned char *ftrace_nop_replace(void)
{
return (char *)&NOP[0];
}
static unsigned char *ftrace_call_replace(unsigned long pc, unsigned long addr)
{
unsigned long hi16, low16;
hi16 = (addr & 0xffff0000) >> 13;
low16 = (addr & 0x0000ffff) << 3;
/*
* The compiler makes the call to mcount_wrapper()
* (Meta's wrapper around mcount()) through the register
* D0.4. So whenever we're patching one of those compiler-generated
* calls we also need to go through D0.4. Otherwise use D1RtP.
*/
if (pc == (unsigned long)&ftrace_call) {
writel(D1RTP_MOVT_TEMPLATE | hi16, &movt_and_call_insn[0]);
writel(D1RTP_CALL_TEMPLATE | low16, &movt_and_call_insn[1]);
} else {
writel(D04_MOVT_TEMPLATE | hi16, &movt_and_call_insn[0]);
writel(D04_CALL_TEMPLATE | low16, &movt_and_call_insn[1]);
}
return (unsigned char *)&movt_and_call_insn[0];
}
static int ftrace_modify_code(unsigned long pc, unsigned char *old_code,
unsigned char *new_code)
{
unsigned char replaced[MCOUNT_INSN_SIZE];
/*
* Note: Due to modules and __init, code can
* disappear and change, we need to protect against faulting
* as well as code changing.
*
* No real locking needed, this code is run through
* kstop_machine.
*/
/* read the text we want to modify */
if (probe_kernel_read(replaced, (void *)pc, MCOUNT_INSN_SIZE))
return -EFAULT;
/* Make sure it is what we expect it to be */
if (memcmp(replaced, old_code, MCOUNT_INSN_SIZE) != 0)
return -EINVAL;
/* replace the text with the new text */
if (probe_kernel_write((void *)pc, new_code, MCOUNT_INSN_SIZE))
return -EPERM;
flush_icache_range(pc, pc + MCOUNT_INSN_SIZE);
return 0;
}
int ftrace_update_ftrace_func(ftrace_func_t func)
{
int ret;
unsigned long pc;
unsigned char old[MCOUNT_INSN_SIZE], *new;
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_nop(struct module *mod,
struct dyn_ftrace *rec, unsigned long addr)
{
unsigned char *new, *old;
unsigned long ip = rec->ip;
old = ftrace_call_replace(ip, addr);
new = ftrace_nop_replace();
return ftrace_modify_code(ip, old, new);
}
int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
{
unsigned char *new, *old;
unsigned long ip = rec->ip;
old = ftrace_nop_replace();
new = ftrace_call_replace(ip, addr);
return ftrace_modify_code(ip, old, new);
}
/* run from kstop_machine */
int __init ftrace_dyn_arch_init(void *data)
{
/* The return code is returned via data */
writel(0, data);
return 0;
}

76
arch/metag/kernel/ftrace_stub.S Normal file
View file

@ -0,0 +1,76 @@
/*
* Copyright (C) 2008 Imagination Technologies Ltd.
* Licensed under the GPL
*
*/
#include <asm/ftrace.h>
.text
#ifdef CONFIG_DYNAMIC_FTRACE
.global _mcount_wrapper
.type _mcount_wrapper,function
_mcount_wrapper:
MOV PC,D0.4
.global _ftrace_caller
.type _ftrace_caller,function
_ftrace_caller:
MOVT D0Re0,#HI(_function_trace_stop)
ADD D0Re0,D0Re0,#LO(_function_trace_stop)
GETD D0Re0,[D0Re0]
CMP D0Re0,#0
BEQ $Lcall_stub
MOV PC,D0.4
$Lcall_stub:
MSETL [A0StP], D0Ar6, D0Ar4, D0Ar2, D0.4
MOV D1Ar1, D0.4
MOV D0Ar2, D1RtP
SUB D1Ar1,D1Ar1,#MCOUNT_INSN_SIZE
.global _ftrace_call
_ftrace_call:
MOVT D1RtP,#HI(_ftrace_stub)
CALL D1RtP,#LO(_ftrace_stub)
GETL D0.4, D1RtP, [A0StP++#(-8)]
GETL D0Ar2, D1Ar1, [A0StP++#(-8)]
GETL D0Ar4, D1Ar3, [A0StP++#(-8)]
GETL D0Ar6, D1Ar5, [A0StP++#(-8)]
MOV PC, D0.4
#else
.global _mcount_wrapper
.type _mcount_wrapper,function
_mcount_wrapper:
MOVT D0Re0,#HI(_function_trace_stop)
ADD D0Re0,D0Re0,#LO(_function_trace_stop)
GETD D0Re0,[D0Re0]
CMP D0Re0,#0
BEQ $Lcall_mcount
MOV PC,D0.4
$Lcall_mcount:
MSETL [A0StP], D0Ar6, D0Ar4, D0Ar2, D0.4
MOV D1Ar1, D0.4
MOV D0Ar2, D1RtP
MOVT D0Re0,#HI(_ftrace_trace_function)
ADD D0Re0,D0Re0,#LO(_ftrace_trace_function)
GET D1Ar3,[D0Re0]
MOVT D1Re0,#HI(_ftrace_stub)
ADD D1Re0,D1Re0,#LO(_ftrace_stub)
CMP D1Ar3,D1Re0
BEQ $Ltrace_exit
MOV D1RtP,D1Ar3
SUB D1Ar1,D1Ar1,#MCOUNT_INSN_SIZE
SWAP PC,D1RtP
$Ltrace_exit:
GETL D0.4, D1RtP, [A0StP++#(-8)]
GETL D0Ar2, D1Ar1, [A0StP++#(-8)]
GETL D0Ar4, D1Ar3, [A0StP++#(-8)]
GETL D0Ar6, D1Ar5, [A0StP++#(-8)]
MOV PC, D0.4
#endif /* CONFIG_DYNAMIC_FTRACE */
.global _ftrace_stub
_ftrace_stub:
MOV PC,D1RtP

5
arch/metag/kernel/metag_ksyms.c
View file

@ -10,6 +10,7 @@
#include <asm/checksum.h>
#include <asm/uaccess.h>
#include <asm/traps.h>
#include <asm/ftrace.h>
#include <asm/tbx.h>
/* uaccess symbols */
@ -73,3 +74,7 @@ EXPORT_SYMBOL(div_s64);
EXPORT_SYMBOL(memcpy);
EXPORT_SYMBOL(memset);
EXPORT_SYMBOL(memmove);
#ifdef CONFIG_FUNCTION_TRACER
EXPORT_SYMBOL(mcount_wrapper);
#endif

13
scripts/recordmcount.c
View file

@ -33,6 +33,13 @@
#include <string.h>
#include <unistd.h>
#ifndef EM_METAG
/* Remove this when these make it to the standard system elf.h. */
#define EM_METAG 174
#define R_METAG_ADDR32 2
#define R_METAG_NONE 3
#endif
static int fd_map; /* File descriptor for file being modified. */
static int mmap_failed; /* Boolean flag. */
static void *ehdr_curr; /* current ElfXX_Ehdr * for resource cleanup */
@ -341,6 +348,12 @@ do_file(char const *const fname)
altmcount = "__gnu_mcount_nc";
break;
case EM_IA_64: reltype = R_IA64_IMM64; gpfx = '_'; break;
case EM_METAG: reltype = R_METAG_ADDR32;
altmcount = "_mcount_wrapper";
rel_type_nop = R_METAG_NONE;
/* We happen to have the same requirement as MIPS */
is_fake_mcount32 = MIPS32_is_fake_mcount;
break;
case EM_MIPS: /* reltype: e_class */ gpfx = '_'; break;
case EM_PPC: reltype = R_PPC_ADDR32; gpfx = '_'; break;
case EM_PPC64: reltype = R_PPC64_ADDR64; gpfx = '_'; break;