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)
28extern void epapr_ev_idle(void);
29extern u32 epapr_ev_idle_start[];
30#endif
31
32bool epapr_paravirt_enabled;
33static bool __maybe_unused epapr_has_idle;
34
35static int __init early_init_dt_scan_epapr(unsigned long node,
36					   const char *uname,
37					   int depth, void *data)
38{
39	const u32 *insts;
40	int len;
41	int i;
42
43	insts = of_get_flat_dt_prop(node, "hcall-instructions", &len);
44	if (!insts)
45		return 0;
46
47	if (len % 4 || len > (4 * 4))
48		return -1;
49
50	for (i = 0; i < (len / 4); i++) {
51		u32 inst = be32_to_cpu(insts[i]);
52		patch_instruction(epapr_hypercall_start + i, inst);
53#if !defined(CONFIG_64BIT) || defined(CONFIG_PPC_BOOK3E_64)
54		patch_instruction(epapr_ev_idle_start + i, inst);
55#endif
56	}
57
58#if !defined(CONFIG_64BIT) || defined(CONFIG_PPC_BOOK3E_64)
59	if (of_get_flat_dt_prop(node, "has-idle", NULL))
60		epapr_has_idle = true;
61#endif
62
63	epapr_paravirt_enabled = true;
64
65	return 1;
66}
67
68int __init epapr_paravirt_early_init(void)
69{
70	of_scan_flat_dt(early_init_dt_scan_epapr, NULL);
71
72	return 0;
73}
74
75static int __init epapr_idle_init(void)
76{
77#if !defined(CONFIG_64BIT) || defined(CONFIG_PPC_BOOK3E_64)
78	if (epapr_has_idle)
79		ppc_md.power_save = epapr_ev_idle;
80#endif
81
82	return 0;
83}
84
85postcore_initcall(epapr_idle_init);
86