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 #include <asm/machdep.h>
25 
26 #if !defined(CONFIG_64BIT) || defined(CONFIG_PPC_BOOK3E_64)
27 extern void epapr_ev_idle(void);
28 extern u32 epapr_ev_idle_start[];
29 #endif
30 
31 bool epapr_paravirt_enabled;
32 
33 static int __init early_init_dt_scan_epapr(unsigned long node,
34 					   const char *uname,
35 					   int depth, void *data)
36 {
37 	const u32 *insts;
38 	unsigned long len;
39 	int i;
40 
41 	insts = of_get_flat_dt_prop(node, "hcall-instructions", &len);
42 	if (!insts)
43 		return 0;
44 
45 	if (len % 4 || len > (4 * 4))
46 		return -1;
47 
48 	for (i = 0; i < (len / 4); i++) {
49 		patch_instruction(epapr_hypercall_start + i, insts[i]);
50 #if !defined(CONFIG_64BIT) || defined(CONFIG_PPC_BOOK3E_64)
51 		patch_instruction(epapr_ev_idle_start + i, insts[i]);
52 #endif
53 	}
54 
55 #if !defined(CONFIG_64BIT) || defined(CONFIG_PPC_BOOK3E_64)
56 	if (of_get_flat_dt_prop(node, "has-idle", NULL))
57 		ppc_md.power_save = epapr_ev_idle;
58 #endif
59 
60 	epapr_paravirt_enabled = true;
61 
62 	return 1;
63 }
64 
65 int __init epapr_paravirt_early_init(void)
66 {
67 	of_scan_flat_dt(early_init_dt_scan_epapr, NULL);
68 
69 	return 0;
70 }
71 
72