[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/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 */