ARC: Make arc_unwind_core accessible externally

The arc unwinder can also be used for perf callchains.

Signed-off-by: Mischa Jonker <mjonker@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>

1 files changed, 37 insertions, 0 deletions

diff --git a/arch/arc/include/asm/stacktrace.h b/arch/arc/include/asm/stacktrace.h
new file mode 100644
index 000000000000..b29b6064ea14
--- /dev/null
+++ b/arch/arc/include/asm/stacktrace.h
@@ -0,0 +1,37 @@
+/*
+ * Copyright (C) 2014-15 Synopsys, Inc. (www.synopsys.com)
+ * Copyright (C) 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#ifndef __ASM_STACKTRACE_H
+#define __ASM_STACKTRACE_H
+
+#include <linux/sched.h>
+
+/**
+ * arc_unwind_core - Unwind the kernel mode stack for an execution context
+ * @tsk:		NULL for current task, specific task otherwise
+ * @regs:		pt_regs used to seed the unwinder {SP, FP, BLINK, PC}
+ * 			If NULL, use pt_regs of @tsk (if !NULL) otherwise
+ * 			use the current values of {SP, FP, BLINK, PC}
+ * @consumer_fn:	Callback invoked for each frame unwound
+ * 			Returns 0 to continue unwinding, -1 to stop
+ * @arg:		Arg to callback
+ *
+ * Returns the address of first function in stack
+ *
+ * Semantics:
+ *  - synchronous unwinding (e.g. dump_stack): @tsk  NULL, @regs  NULL
+ *  - Asynchronous unwinding of sleeping task: @tsk !NULL, @regs  NULL
+ *  - Asynchronous unwinding of intr/excp etc: @tsk !NULL, @regs !NULL
+ */
+notrace noinline unsigned int arc_unwind_core(
+	struct task_struct *tsk, struct pt_regs *regs,
+	int (*consumer_fn) (unsigned int, void *),
+	void *arg);
+
+#endif /* __ASM_STACKTRACE_H */