powerpc/livepatch: Add livepatch header

/*

 * livepatch.h - powerpc-specific Kernel Live Patching Core

 *

 * Copyright (C) 2015-2016, SUSE, IBM Corp.

 *

 * This program is free software; you can redistribute it and/or

 * modify it under the terms of the GNU General Public License

 * as published by the Free Software Foundation; either version 2

 * of the License, or (at your option) any later version.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program; if not, see <http://www.gnu.org/licenses/>.

 */

#ifndef _ASM_POWERPC_LIVEPATCH_H

#define _ASM_POWERPC_LIVEPATCH_H

#include <linux/module.h>

#include <linux/ftrace.h>

#ifdef CONFIG_LIVEPATCH

static inline int klp_check_compiler_support(void)

{

	return 0;

}

static inline int klp_write_module_reloc(struct module *mod, unsigned long

		type, unsigned long loc, unsigned long value)

{

	/* This requires infrastructure changes; we need the loadinfos. */

	return -ENOSYS;

}

static inline void klp_arch_set_pc(struct pt_regs *regs, unsigned long ip)

{

	regs->nip = ip;

}

#define klp_get_ftrace_location klp_get_ftrace_location

static inline unsigned long klp_get_ftrace_location(unsigned long faddr)

{

	/*

	 * Live patch works only with -mprofile-kernel on PPC. In this case,

	 * the ftrace location is always within the first 16 bytes.

	 */

	return ftrace_location_range(faddr, faddr + 16);

}

#endif /* CONFIG_LIVEPATCH */

#endif /* _ASM_POWERPC_LIVEPATCH_H */