v4.19.13 snapshot.
diff --git a/arch/parisc/kernel/ftrace.c b/arch/parisc/kernel/ftrace.c
new file mode 100644
index 0000000..e46a415
--- /dev/null
+++ b/arch/parisc/kernel/ftrace.c
@@ -0,0 +1,78 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Code for tracing calls in Linux kernel.
+ * Copyright (C) 2009-2016 Helge Deller <deller@gmx.de>
+ *
+ * based on code for x86 which is:
+ * Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com>
+ *
+ * future possible enhancements:
+ * - add CONFIG_DYNAMIC_FTRACE
+ * - add CONFIG_STACK_TRACER
+ */
+
+#include <linux/init.h>
+#include <linux/ftrace.h>
+
+#include <asm/assembly.h>
+#include <asm/sections.h>
+#include <asm/ftrace.h>
+
+
+#define __hot __attribute__ ((__section__ (".text.hot")))
+
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+/*
+ * Hook the return address and push it in the stack of return addrs
+ * in current thread info.
+ */
+static void __hot prepare_ftrace_return(unsigned long *parent,
+ unsigned long self_addr)
+{
+ unsigned long old;
+ extern int parisc_return_to_handler;
+
+ if (unlikely(ftrace_graph_is_dead()))
+ return;
+
+ if (unlikely(atomic_read(¤t->tracing_graph_pause)))
+ return;
+
+ old = *parent;
+
+ if (!function_graph_enter(old, self_addr, 0, NULL))
+ /* activate parisc_return_to_handler() as return point */
+ *parent = (unsigned long) &parisc_return_to_handler;
+}
+#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
+
+void notrace __hot ftrace_function_trampoline(unsigned long parent,
+ unsigned long self_addr,
+ unsigned long org_sp_gr3)
+{
+ extern ftrace_func_t ftrace_trace_function; /* depends on CONFIG_DYNAMIC_FTRACE */
+ extern int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace);
+
+ if (ftrace_trace_function != ftrace_stub) {
+ /* struct ftrace_ops *op, struct pt_regs *regs); */
+ ftrace_trace_function(parent, self_addr, NULL, NULL);
+ return;
+ }
+
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+ if (ftrace_graph_return != (trace_func_graph_ret_t) ftrace_stub ||
+ ftrace_graph_entry != ftrace_graph_entry_stub) {
+ unsigned long *parent_rp;
+
+ /* calculate pointer to %rp in stack */
+ parent_rp = (unsigned long *) (org_sp_gr3 - RP_OFFSET);
+ /* sanity check: parent_rp should hold parent */
+ if (*parent_rp != parent)
+ return;
+
+ prepare_ftrace_return(parent_rp, self_addr);
+ return;
+ }
+#endif
+}
+