powerpc: Move the patch_exception to a common place

So that it can be used by other codes. No function change.

Signed-off-by: Kevin Hao <haokexin@gmail.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

arch/powerpc/lib/code-patching.c

@@ -159,6 +159,21 @@ unsigned int translate_branch(const unsigned int *dest, const unsigned int *src)
 	return 0;
 }
 
+#ifdef CONFIG_PPC_BOOK3E_64
+void __patch_exception(int exc, unsigned long addr)
+{
+	extern unsigned int interrupt_base_book3e;
+	unsigned int *ibase = &interrupt_base_book3e;
+
+	/* Our exceptions vectors start with a NOP and -then- a branch
+	 * to deal with single stepping from userspace which stops on
+	 * the second instruction. Thus we need to patch the second
+	 * instruction of the exception, not the first one
+	 */
+
+	patch_branch(ibase + (exc / 4) + 1, addr, 0);
+}
+#endif
 
 #ifdef CONFIG_CODE_PATCHING_SELFTEST