parisc: add parisc code patching

Instead of re-mapping the whole kernel text with RWX rights
add a patch_text() which can be used to replace instructions
in the kernel .text section. Based on the ARM implementation.

Signed-off-by: Sven Schnelle <svens@stackframe.org>
Signed-off-by: Helge Deller <deller@gmx.de>

arch/parisc/include/asm/patch.h

@@ -0,0 +1,11 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _PARISC_KERNEL_PATCH_H
+#define _PARISC_KERNEL_PATCH_H
+
+/* stop machine and patch kernel text */
+void patch_text(void *addr, unsigned int insn);
+
+/* patch kernel text with machine already stopped (e.g. in kgdb) */
+void __patch_text(void *addr, unsigned int insn);
+
+#endif