[S390] ftrace: function tracer backend for s390
This implements just the basic function tracer (_mcount) backend for s390.
The dynamic variant will come later.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index 90ba5d3..e6efc12 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -74,6 +74,7 @@
config S390
def_bool y
select USE_GENERIC_SMP_HELPERS if SMP
+ select HAVE_FUNCTION_TRACER
select HAVE_OPROFILE
select HAVE_KPROBES
select HAVE_KRETPROBES
diff --git a/arch/s390/include/asm/ftrace.h b/arch/s390/include/asm/ftrace.h
new file mode 100644
index 0000000..5a5bc75
--- /dev/null
+++ b/arch/s390/include/asm/ftrace.h
@@ -0,0 +1,8 @@
+#ifndef _ASM_S390_FTRACE_H
+#define _ASM_S390_FTRACE_H
+
+#ifndef __ASSEMBLY__
+extern void _mcount(void);
+#endif
+
+#endif /* _ASM_S390_FTRACE_H */
diff --git a/arch/s390/kernel/Makefile b/arch/s390/kernel/Makefile
index 235b948..92730cc 100644
--- a/arch/s390/kernel/Makefile
+++ b/arch/s390/kernel/Makefile
@@ -2,6 +2,11 @@
# Makefile for the linux kernel.
#
+ifdef CONFIG_FUNCTION_TRACER
+# Do not trace early boot code
+CFLAGS_REMOVE_early.o = -pg
+endif
+
#
# Passing null pointers is ok for smp code, since we access the lowcore here.
#
@@ -34,6 +39,7 @@
obj-$(CONFIG_VIRT_TIMER) += vtime.o
obj-$(CONFIG_STACKTRACE) += stacktrace.o
obj-$(CONFIG_KPROBES) += kprobes.o
+obj-$(CONFIG_FUNCTION_TRACER) += mcount.o
# Kexec part
S390_KEXEC_OBJS := machine_kexec.o crash.o
diff --git a/arch/s390/kernel/mcount.S b/arch/s390/kernel/mcount.S
new file mode 100644
index 0000000..397d131
--- /dev/null
+++ b/arch/s390/kernel/mcount.S
@@ -0,0 +1,56 @@
+/*
+ * Copyright IBM Corp. 2008
+ *
+ * Author(s): Heiko Carstens <heiko.carstens@de.ibm.com>,
+ *
+ */
+
+#ifndef CONFIG_64BIT
+.globl _mcount
+_mcount:
+ stm %r0,%r5,8(%r15)
+ st %r14,56(%r15)
+ lr %r1,%r15
+ ahi %r15,-96
+ l %r3,100(%r15)
+ la %r2,0(%r14)
+ st %r1,0(%r15)
+ la %r3,0(%r3)
+ bras %r14,0f
+ .long ftrace_trace_function
+0: l %r14,0(%r14)
+ l %r14,0(%r14)
+ basr %r14,%r14
+ ahi %r15,96
+ lm %r0,%r5,8(%r15)
+ l %r14,56(%r15)
+ br %r14
+
+.globl ftrace_stub
+ftrace_stub:
+ br %r14
+
+#else /* CONFIG_64BIT */
+
+.globl _mcount
+_mcount:
+ stmg %r0,%r5,16(%r15)
+ stg %r14,112(%r15)
+ lgr %r1,%r15
+ aghi %r15,-160
+ stg %r1,0(%r15)
+ lgr %r2,%r14
+ lg %r3,168(%r15)
+ larl %r14,ftrace_trace_function
+ lg %r14,0(%r14)
+ basr %r14,%r14
+ aghi %r15,160
+ lmg %r0,%r5,16(%r15)
+ lg %r14,112(%r15)
+ br %r14
+
+.globl ftrace_stub
+ftrace_stub:
+ br %r14
+
+#endif /* CONFIG_64BIT */
diff --git a/arch/s390/kernel/s390_ksyms.c b/arch/s390/kernel/s390_ksyms.c
index 48238a1..46b90cb 100644
--- a/arch/s390/kernel/s390_ksyms.c
+++ b/arch/s390/kernel/s390_ksyms.c
@@ -14,6 +14,7 @@
#include <asm/delay.h>
#include <asm/pgalloc.h>
#include <asm/setup.h>
+#include <asm/ftrace.h>
#ifdef CONFIG_IP_MULTICAST
#include <net/arp.h>
#endif
@@ -43,3 +44,7 @@
EXPORT_SYMBOL(console_mode);
EXPORT_SYMBOL(console_devno);
EXPORT_SYMBOL(console_irq);
+
+#ifdef CONFIG_FUNCTION_TRACER
+EXPORT_SYMBOL(_mcount);
+#endif