Re: [PATCH v2 11/13] powerpc/ftrace: directly call of function graph tracer by ftrace caller

Modify function graph tracer to be handled directly by the standard
ftrace caller.

This is made possible as powerpc now supports
CONFIG_DYNAMIC_FTRACE_WITH_ARGS.

This change simplifies the call of function graph ftrace.

Signed-off-by: Christophe Leroy <redacted>
---
 arch/powerpc/include/asm/ftrace.h             |  6 ++
 arch/powerpc/kernel/trace/ftrace.c            | 11 ++++
 arch/powerpc/kernel/trace/ftrace_32.S         | 53 +--------------
 .../powerpc/kernel/trace/ftrace_64_mprofile.S | 64 +------------------
 4 files changed, 20 insertions(+), 114 deletions(-)

diff --git a/arch/powerpc/include/asm/ftrace.h b/arch/powerpc/include/asm/ftrace.h
index 45c3d6f11daa..70b457097098 100644
--- a/arch/powerpc/include/asm/ftrace.h
+++ b/arch/powerpc/include/asm/ftrace.h

@@ -38,6 +38,12 @@ static __always_inline void ftrace_instruction_pointer_set(struct ftrace_regs *f
 {
 	regs_set_return_ip(&fregs->regs, ip);
 }
+
+struct ftrace_ops;
+
+#define ftrace_graph_func ftrace_graph_func
+void ftrace_graph_func(unsigned long ip, unsigned long parent_ip,
+		       struct ftrace_ops *op, struct ftrace_regs *fregs);
 #endif
 #endif /* __ASSEMBLY__ */
 

diff --git a/arch/powerpc/kernel/trace/ftrace.c b/arch/powerpc/kernel/trace/ftrace.c
index ce673764cb69..74a176e394ef 100644
--- a/arch/powerpc/kernel/trace/ftrace.c
+++ b/arch/powerpc/kernel/trace/ftrace.c

@@ -917,6 +917,9 @@ static int ftrace_modify_ftrace_graph_caller(bool enable)
 	unsigned long stub = (unsigned long)(&ftrace_graph_stub);
 	ppc_inst_t old, new;
 
+	if (IS_ENABLED(CONFIG_DYNAMIC_FTRACE_WITH_ARGS))
+		return 0;
+
 	old = ftrace_call_replace(ip, enable ? stub : addr, 0);
 	new = ftrace_call_replace(ip, enable ? addr : stub, 0);
 

@@ -955,6 +958,14 @@ unsigned long prepare_ftrace_return(unsigned long parent, unsigned long ip,
 out:
 	return parent;
 }