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 <linux/of_fdt.h>
22 #include <asm/epapr_hcalls.h>
23 #include <asm/cacheflush.h>
24 #include <asm/code-patching.h>
25 #include <asm/machdep.h>
26 
27 #if !defined(CONFIG_64BIT) || defined(CONFIG_PPC_BOOK3E_64)
28 extern void epapr_ev_idle(void);
29 extern u32 epapr_ev_idle_start[];
30 #endif
31 
32 bool epapr_paravirt_enabled;
33 
34 static int __init early_init_dt_scan_epapr(unsigned long node,
35 					   const char *uname,
36 					   int depth, void *data)
37 {
38 	const u32 *insts;
39 	int len;
40 	int i;
41 
42 	insts = of_get_flat_dt_prop(node, "hcall-instructions", &len);
43 	if (!insts)
44 		return 0;
45 
46 	if (len % 4 || len > (4 * 4))
47 		return -1;
48 
49 	for (i = 0; i < (len / 4); i++) {
50 		u32 inst = be32_to_cpu(insts[i]);
51 		patch_instruction(epapr_hypercall_start + i, inst);
52 #if !defined(CONFIG_64BIT) || defined(CONFIG_PPC_BOOK3E_64)
53 		patch_instruction(epapr_ev_idle_start + i, inst);
54 #endif
55 	}
56 
57 #if !defined(CONFIG_64BIT) || defined(CONFIG_PPC_BOOK3E_64)
58 	if (of_get_flat_dt_prop(node, "has-idle", NULL))
59 		ppc_md.power_save = epapr_ev_idle;
60 #endif
61 
62 	epapr_paravirt_enabled = true;
63 
64 	return 1;
65 }
66 
67 int __init epapr_paravirt_early_init(void)
68 {
69 	of_scan_flat_dt(early_init_dt_scan_epapr, NULL);
70 
71 	return 0;
72 }
73 
74