1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
|
/*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* 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.
*
* Copyright (C) 2013 ARM Limited
*
* Author: Will Deacon <will.deacon@arm.com>
*/
#define pr_fmt(fmt) "psci: " fmt
#include <linux/init.h>
#include <linux/of.h>
#include <asm/compiler.h>
#include <asm/errno.h>
#include <asm/psci.h>
struct psci_operations psci_ops;
static int (*invoke_psci_fn)(u64, u64, u64, u64);
enum psci_function {
PSCI_FN_CPU_SUSPEND,
PSCI_FN_CPU_ON,
PSCI_FN_CPU_OFF,
PSCI_FN_MIGRATE,
PSCI_FN_MAX,
};
static u32 psci_function_id[PSCI_FN_MAX];
#define PSCI_RET_SUCCESS 0
#define PSCI_RET_EOPNOTSUPP -1
#define PSCI_RET_EINVAL -2
#define PSCI_RET_EPERM -3
static int psci_to_linux_errno(int errno)
{
switch (errno) {
case PSCI_RET_SUCCESS:
return 0;
case PSCI_RET_EOPNOTSUPP:
return -EOPNOTSUPP;
case PSCI_RET_EINVAL:
return -EINVAL;
case PSCI_RET_EPERM:
return -EPERM;
};
return -EINVAL;
}
#define PSCI_POWER_STATE_ID_MASK 0xffff
#define PSCI_POWER_STATE_ID_SHIFT 0
#define PSCI_POWER_STATE_TYPE_MASK 0x1
#define PSCI_POWER_STATE_TYPE_SHIFT 16
#define PSCI_POWER_STATE_AFFL_MASK 0x3
#define PSCI_POWER_STATE_AFFL_SHIFT 24
static u32 psci_power_state_pack(struct psci_power_state state)
{
return ((state.id & PSCI_POWER_STATE_ID_MASK)
<< PSCI_POWER_STATE_ID_SHIFT) |
((state.type & PSCI_POWER_STATE_TYPE_MASK)
<< PSCI_POWER_STATE_TYPE_SHIFT) |
((state.affinity_level & PSCI_POWER_STATE_AFFL_MASK)
<< PSCI_POWER_STATE_AFFL_SHIFT);
}
/*
* The following two functions are invoked via the invoke_psci_fn pointer
* and will not be inlined, allowing us to piggyback on the AAPCS.
*/
static noinline int __invoke_psci_fn_hvc(u64 function_id, u64 arg0, u64 arg1,
u64 arg2)
{
asm volatile(
__asmeq("%0", "x0")
__asmeq("%1", "x1")
__asmeq("%2", "x2")
__asmeq("%3", "x3")
"hvc #0\n"
: "+r" (function_id)
: "r" (arg0), "r" (arg1), "r" (arg2));
return function_id;
}
static noinline int __invoke_psci_fn_smc(u64 function_id, u64 arg0, u64 arg1,
u64 arg2)
{
asm volatile(
__asmeq("%0", "x0")
__asmeq("%1", "x1")
__asmeq("%2", "x2")
__asmeq("%3", "x3")
"smc #0\n"
: "+r" (function_id)
: "r" (arg0), "r" (arg1), "r" (arg2));
return function_id;
}
static int psci_cpu_suspend(struct psci_power_state state,
unsigned long entry_point)
{
int err;
u32 fn, power_state;
fn = psci_function_id[PSCI_FN_CPU_SUSPEND];
power_state = psci_power_state_pack(state);
err = invoke_psci_fn(fn, power_state, entry_point, 0);
return psci_to_linux_errno(err);
}
static int psci_cpu_off(struct psci_power_state state)
{
int err;
u32 fn, power_state;
fn = psci_function_id[PSCI_FN_CPU_OFF];
power_state = psci_power_state_pack(state);
err = invoke_psci_fn(fn, power_state, 0, 0);
return psci_to_linux_errno(err);
}
static int psci_cpu_on(unsigned long cpuid, unsigned long entry_point)
{
int err;
u32 fn;
fn = psci_function_id[PSCI_FN_CPU_ON];
err = invoke_psci_fn(fn, cpuid, entry_point, 0);
return psci_to_linux_errno(err);
}
static int psci_migrate(unsigned long cpuid)
{
int err;
u32 fn;
fn = psci_function_id[PSCI_FN_MIGRATE];
err = invoke_psci_fn(fn, cpuid, 0, 0);
return psci_to_linux_errno(err);
}
static const struct of_device_id psci_of_match[] __initconst = {
{ .compatible = "arm,psci", },
{},
};
int __init psci_init(void)
{
struct device_node *np;
const char *method;
u32 id;
int err = 0;
np = of_find_matching_node(NULL, psci_of_match);
if (!np)
return -ENODEV;
pr_info("probing function IDs from device-tree\n");
if (of_property_read_string(np, "method", &method)) {
pr_warning("missing \"method\" property\n");
err = -ENXIO;
goto out_put_node;
}
if (!strcmp("hvc", method)) {
invoke_psci_fn = __invoke_psci_fn_hvc;
} else if (!strcmp("smc", method)) {
invoke_psci_fn = __invoke_psci_fn_smc;
} else {
pr_warning("invalid \"method\" property: %s\n", method);
err = -EINVAL;
goto out_put_node;
}
if (!of_property_read_u32(np, "cpu_suspend", &id)) {
psci_function_id[PSCI_FN_CPU_SUSPEND] = id;
psci_ops.cpu_suspend = psci_cpu_suspend;
}
if (!of_property_read_u32(np, "cpu_off", &id)) {
psci_function_id[PSCI_FN_CPU_OFF] = id;
psci_ops.cpu_off = psci_cpu_off;
}
if (!of_property_read_u32(np, "cpu_on", &id)) {
psci_function_id[PSCI_FN_CPU_ON] = id;
psci_ops.cpu_on = psci_cpu_on;
}
if (!of_property_read_u32(np, "migrate", &id)) {
psci_function_id[PSCI_FN_MIGRATE] = id;
psci_ops.migrate = psci_migrate;
}
out_put_node:
of_node_put(np);
return err;
}
|
