1 /*
2  * ePAPR para-virtualization support.
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License, version 2, as
6  * published by the Free Software Foundation.
7  *
8  * This program is distributed in the hope that it will be useful,
9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
11  * GNU General Public License for more details.
12  *
13  * You should have received a copy of the GNU General Public License
14  * along with this program; if not, write to the Free Software
15  * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
16  *
17  * Copyright (C) 2012 Freescale Semiconductor, Inc.
18  */
19 
20 #include <linux/of.h>
21 #include <asm/epapr_hcalls.h>
22 #include <asm/cacheflush.h>
23 #include <asm/code-patching.h>
24 
25 bool epapr_paravirt_enabled;
26 
27 static int __init epapr_paravirt_init(void)
28 {
29 	struct device_node *hyper_node;
30 	const u32 *insts;
31 	int len, i;
32 
33 	hyper_node = of_find_node_by_path("/hypervisor");
34 	if (!hyper_node)
35 		return -ENODEV;
36 
37 	insts = of_get_property(hyper_node, "hcall-instructions", &len);
38 	if (!insts)
39 		return -ENODEV;
40 
41 	if (len % 4 || len > (4 * 4))
42 		return -ENODEV;
43 
44 	for (i = 0; i < (len / 4); i++)
45 		patch_instruction(epapr_hypercall_start + i, insts[i]);
46 
47 	epapr_paravirt_enabled = true;
48 
49 	return 0;
50 }
51 
52 early_initcall(epapr_paravirt_init);
53