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16#define pr_fmt(fmt) "psci: " fmt
17
18#include <linux/init.h>
19#include <linux/of.h>
20
21#include <asm/compiler.h>
22#include <asm/errno.h>
23#include <asm/psci.h>
24
25struct psci_operations psci_ops;
26
27static int (*invoke_psci_fn)(u64, u64, u64, u64);
28
29enum psci_function {
30 PSCI_FN_CPU_SUSPEND,
31 PSCI_FN_CPU_ON,
32 PSCI_FN_CPU_OFF,
33 PSCI_FN_MIGRATE,
34 PSCI_FN_MAX,
35};
36
37static u32 psci_function_id[PSCI_FN_MAX];
38
39#define PSCI_RET_SUCCESS 0
40#define PSCI_RET_EOPNOTSUPP -1
41#define PSCI_RET_EINVAL -2
42#define PSCI_RET_EPERM -3
43
44static int psci_to_linux_errno(int errno)
45{
46 switch (errno) {
47 case PSCI_RET_SUCCESS:
48 return 0;
49 case PSCI_RET_EOPNOTSUPP:
50 return -EOPNOTSUPP;
51 case PSCI_RET_EINVAL:
52 return -EINVAL;
53 case PSCI_RET_EPERM:
54 return -EPERM;
55 };
56
57 return -EINVAL;
58}
59
60#define PSCI_POWER_STATE_ID_MASK 0xffff
61#define PSCI_POWER_STATE_ID_SHIFT 0
62#define PSCI_POWER_STATE_TYPE_MASK 0x1
63#define PSCI_POWER_STATE_TYPE_SHIFT 16
64#define PSCI_POWER_STATE_AFFL_MASK 0x3
65#define PSCI_POWER_STATE_AFFL_SHIFT 24
66
67static u32 psci_power_state_pack(struct psci_power_state state)
68{
69 return ((state.id & PSCI_POWER_STATE_ID_MASK)
70 << PSCI_POWER_STATE_ID_SHIFT) |
71 ((state.type & PSCI_POWER_STATE_TYPE_MASK)
72 << PSCI_POWER_STATE_TYPE_SHIFT) |
73 ((state.affinity_level & PSCI_POWER_STATE_AFFL_MASK)
74 << PSCI_POWER_STATE_AFFL_SHIFT);
75}
76
77
78
79
80
81static noinline int __invoke_psci_fn_hvc(u64 function_id, u64 arg0, u64 arg1,
82 u64 arg2)
83{
84 asm volatile(
85 __asmeq("%0", "x0")
86 __asmeq("%1", "x1")
87 __asmeq("%2", "x2")
88 __asmeq("%3", "x3")
89 "hvc #0\n"
90 : "+r" (function_id)
91 : "r" (arg0), "r" (arg1), "r" (arg2));
92
93 return function_id;
94}
95
96static noinline int __invoke_psci_fn_smc(u64 function_id, u64 arg0, u64 arg1,
97 u64 arg2)
98{
99 asm volatile(
100 __asmeq("%0", "x0")
101 __asmeq("%1", "x1")
102 __asmeq("%2", "x2")
103 __asmeq("%3", "x3")
104 "smc #0\n"
105 : "+r" (function_id)
106 : "r" (arg0), "r" (arg1), "r" (arg2));
107
108 return function_id;
109}
110
111static int psci_cpu_suspend(struct psci_power_state state,
112 unsigned long entry_point)
113{
114 int err;
115 u32 fn, power_state;
116
117 fn = psci_function_id[PSCI_FN_CPU_SUSPEND];
118 power_state = psci_power_state_pack(state);
119 err = invoke_psci_fn(fn, power_state, entry_point, 0);
120 return psci_to_linux_errno(err);
121}
122
123static int psci_cpu_off(struct psci_power_state state)
124{
125 int err;
126 u32 fn, power_state;
127
128 fn = psci_function_id[PSCI_FN_CPU_OFF];
129 power_state = psci_power_state_pack(state);
130 err = invoke_psci_fn(fn, power_state, 0, 0);
131 return psci_to_linux_errno(err);
132}
133
134static int psci_cpu_on(unsigned long cpuid, unsigned long entry_point)
135{
136 int err;
137 u32 fn;
138
139 fn = psci_function_id[PSCI_FN_CPU_ON];
140 err = invoke_psci_fn(fn, cpuid, entry_point, 0);
141 return psci_to_linux_errno(err);
142}
143
144static int psci_migrate(unsigned long cpuid)
145{
146 int err;
147 u32 fn;
148
149 fn = psci_function_id[PSCI_FN_MIGRATE];
150 err = invoke_psci_fn(fn, cpuid, 0, 0);
151 return psci_to_linux_errno(err);
152}
153
154static const struct of_device_id psci_of_match[] __initconst = {
155 { .compatible = "arm,psci", },
156 {},
157};
158
159int __init psci_init(void)
160{
161 struct device_node *np;
162 const char *method;
163 u32 id;
164 int err = 0;
165
166 np = of_find_matching_node(NULL, psci_of_match);
167 if (!np)
168 return -ENODEV;
169
170 pr_info("probing function IDs from device-tree\n");
171
172 if (of_property_read_string(np, "method", &method)) {
173 pr_warning("missing \"method\" property\n");
174 err = -ENXIO;
175 goto out_put_node;
176 }
177
178 if (!strcmp("hvc", method)) {
179 invoke_psci_fn = __invoke_psci_fn_hvc;
180 } else if (!strcmp("smc", method)) {
181 invoke_psci_fn = __invoke_psci_fn_smc;
182 } else {
183 pr_warning("invalid \"method\" property: %s\n", method);
184 err = -EINVAL;
185 goto out_put_node;
186 }
187
188 if (!of_property_read_u32(np, "cpu_suspend", &id)) {
189 psci_function_id[PSCI_FN_CPU_SUSPEND] = id;
190 psci_ops.cpu_suspend = psci_cpu_suspend;
191 }
192
193 if (!of_property_read_u32(np, "cpu_off", &id)) {
194 psci_function_id[PSCI_FN_CPU_OFF] = id;
195 psci_ops.cpu_off = psci_cpu_off;
196 }
197
198 if (!of_property_read_u32(np, "cpu_on", &id)) {
199 psci_function_id[PSCI_FN_CPU_ON] = id;
200 psci_ops.cpu_on = psci_cpu_on;
201 }
202
203 if (!of_property_read_u32(np, "migrate", &id)) {
204 psci_function_id[PSCI_FN_MIGRATE] = id;
205 psci_ops.migrate = psci_migrate;
206 }
207
208out_put_node:
209 of_node_put(np);
210 return err;
211}
212
