ftrace: powerpc clean ups
This patch cleans up the ftrace code in PowerPC based on the comments from
Michael Ellerman.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Cc: Michael Ellerman <michael@ellerman.id.au>
Cc: proski@gnu.org
Cc: a.p.zijlstra@chello.nl
Cc: Pekka Paalanen <pq@iki.fi>
Cc: Steven Rostedt <srostedt@redhat.com>
Cc: linuxppc-dev@ozlabs.org
Cc: Soeren Sandmann Pedersen <sandmann@redhat.com>
Cc: paulus@samba.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index 0e62218..3b1dd29 100644
--- a/arch/powerpc/kernel/entry_32.S
+++ b/arch/powerpc/kernel/entry_32.S
@@ -1129,18 +1129,11 @@
stw r5, 8(r1)
LOAD_REG_ADDR(r5, ftrace_trace_function)
-#if 0
- mtctr r3
- mr r1, r5
- bctrl
-#endif
lwz r5,0(r5)
-#if 1
+
mtctr r5
bctrl
-#else
- bl ftrace_stub
-#endif
+
nop
lwz r6, 8(r1)
diff --git a/arch/powerpc/kernel/ftrace.c b/arch/powerpc/kernel/ftrace.c
index 5a4993f..69ed412 100644
--- a/arch/powerpc/kernel/ftrace.c
+++ b/arch/powerpc/kernel/ftrace.c
@@ -51,10 +51,16 @@
{
static unsigned int op;
+ /*
+ * It would be nice to just use create_function_call, but that will
+ * update the code itself. Here we need to just return the
+ * instruction that is going to be modified, without modifying the
+ * code.
+ */
addr = GET_ADDR(addr);
/* Set to "bl addr" */
- op = 0x48000001 | (ftrace_calc_offset(ip, addr) & 0x03fffffe);
+ op = 0x48000001 | (ftrace_calc_offset(ip, addr) & 0x03fffffc);
/*
* No locking needed, this must be called via kstop_machine
diff --git a/arch/powerpc/kernel/ppc_ksyms.c b/arch/powerpc/kernel/ppc_ksyms.c
index cf6b5a7..4300db5 100644
--- a/arch/powerpc/kernel/ppc_ksyms.c
+++ b/arch/powerpc/kernel/ppc_ksyms.c
@@ -43,6 +43,7 @@
#include <asm/div64.h>
#include <asm/signal.h>
#include <asm/dcr.h>
+#include <asm/ftrace.h>
#ifdef CONFIG_PPC32
extern void transfer_to_handler(void);
@@ -68,6 +69,10 @@
EXPORT_SYMBOL(sys_sigreturn);
#endif
+#ifdef CONFIG_FTRACE
+EXPORT_SYMBOL(_mcount);
+#endif
+
EXPORT_SYMBOL(strcpy);
EXPORT_SYMBOL(strncpy);
EXPORT_SYMBOL(strcat);
diff --git a/arch/powerpc/kernel/setup_32.c b/arch/powerpc/kernel/setup_32.c
index 22f8e2b..19e8fcb 100644
--- a/arch/powerpc/kernel/setup_32.c
+++ b/arch/powerpc/kernel/setup_32.c
@@ -47,11 +47,6 @@
#include <asm/kgdb.h>
#endif
-#ifdef CONFIG_FTRACE
-extern void _mcount(void);
-EXPORT_SYMBOL(_mcount);
-#endif
-
extern void bootx_init(unsigned long r4, unsigned long phys);
int boot_cpuid;
diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c
index 277bf18..098fd96 100644
--- a/arch/powerpc/kernel/setup_64.c
+++ b/arch/powerpc/kernel/setup_64.c
@@ -85,11 +85,6 @@
};
EXPORT_SYMBOL_GPL(ppc64_caches);
-#ifdef CONFIG_FTRACE
-extern void _mcount(void);
-EXPORT_SYMBOL(_mcount);
-#endif
-
/*
* These are used in binfmt_elf.c to put aux entries on the stack
* for each elf executable being started.
diff --git a/include/asm-powerpc/ftrace.h b/include/asm-powerpc/ftrace.h
new file mode 100644
index 0000000..b1bfa70
--- /dev/null
+++ b/include/asm-powerpc/ftrace.h
@@ -0,0 +1,6 @@
+#ifndef _ASM_POWERPC_FTRACE
+#define _ASM_POWERPC_FTRACE
+
+extern void _mcount(void);
+
+#endif