sh: Setup the frame register in asm code
In order to use DWARF unwinder info the frame register has to contain a
valid value. Whilst GCC takes care of this for C code, we have to do it
ourselves for assembly.
Signed-off-by: Matt Fleming <matt@console-pimps.org>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
diff --git a/arch/sh/include/asm/entry-macros.S b/arch/sh/include/asm/entry-macros.S
index 1bdd938..64fd0de 100644
--- a/arch/sh/include/asm/entry-macros.S
+++ b/arch/sh/include/asm/entry-macros.S
@@ -108,3 +108,15 @@
#else
# define PREF(x) nop
#endif
+
+ /*
+ * Macro for use within assembly. Because the DWARF unwinder
+ * needs to use the frame register to unwind the stack, we
+ * need to setup r14 with the value of the stack pointer as
+ * the return address is usually on the stack somewhere.
+ */
+ .macro setup_frame_reg
+#ifdef CONFIG_DWARF_UNWINDER
+ mov r15, r14
+#endif
+ .endm