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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/opcodes-sec.h>
24#include <asm/opcodes-virt.h>
25#include <asm/psci.h>
26
27struct psci_operations psci_ops;
28
29static int (*invoke_psci_fn)(u32, u32, u32, u32);
30
31enum psci_function {
32 PSCI_FN_CPU_SUSPEND,
33 PSCI_FN_CPU_ON,
34 PSCI_FN_CPU_OFF,
35 PSCI_FN_MIGRATE,
36 PSCI_FN_MAX,
37};
38
39static u32 psci_function_id[PSCI_FN_MAX];
40
41#define PSCI_RET_SUCCESS 0
42#define PSCI_RET_EOPNOTSUPP -1
43#define PSCI_RET_EINVAL -2
44#define PSCI_RET_EPERM -3
45
46static int psci_to_linux_errno(int errno)
47{
48 switch (errno) {
49 case PSCI_RET_SUCCESS:
50 return 0;
51 case PSCI_RET_EOPNOTSUPP:
52 return -EOPNOTSUPP;
53 case PSCI_RET_EINVAL:
54 return -EINVAL;
55 case PSCI_RET_EPERM:
56 return -EPERM;
57 };
58
59 return -EINVAL;
60}
61
62#define PSCI_POWER_STATE_ID_MASK 0xffff
63#define PSCI_POWER_STATE_ID_SHIFT 0
64#define PSCI_POWER_STATE_TYPE_MASK 0x1
65#define PSCI_POWER_STATE_TYPE_SHIFT 16
66#define PSCI_POWER_STATE_AFFL_MASK 0x3
67#define PSCI_POWER_STATE_AFFL_SHIFT 24
68
69static u32 psci_power_state_pack(struct psci_power_state state)
70{
71 return ((state.id & PSCI_POWER_STATE_ID_MASK)
72 << PSCI_POWER_STATE_ID_SHIFT) |
73 ((state.type & PSCI_POWER_STATE_TYPE_MASK)
74 << PSCI_POWER_STATE_TYPE_SHIFT) |
75 ((state.affinity_level & PSCI_POWER_STATE_AFFL_MASK)
76 << PSCI_POWER_STATE_AFFL_SHIFT);
77}
78
79
80
81
82
83static noinline int __invoke_psci_fn_hvc(u32 function_id, u32 arg0, u32 arg1,
84 u32 arg2)
85{
86 asm volatile(
87 __asmeq("%0", "r0")
88 __asmeq("%1", "r1")
89 __asmeq("%2", "r2")
90 __asmeq("%3", "r3")
91 __HVC(0)
92 : "+r" (function_id)
93 : "r" (arg0), "r" (arg1), "r" (arg2));
94
95 return function_id;
96}
97
98static noinline int __invoke_psci_fn_smc(u32 function_id, u32 arg0, u32 arg1,
99 u32 arg2)
100{
101 asm volatile(
102 __asmeq("%0", "r0")
103 __asmeq("%1", "r1")
104 __asmeq("%2", "r2")
105 __asmeq("%3", "r3")
106 __SMC(0)
107 : "+r" (function_id)
108 : "r" (arg0), "r" (arg1), "r" (arg2));
109
110 return function_id;
111}
112
113static int psci_cpu_suspend(struct psci_power_state state,
114 unsigned long entry_point)
115{
116 int err;
117 u32 fn, power_state;
118
119 fn = psci_function_id[PSCI_FN_CPU_SUSPEND];
120 power_state = psci_power_state_pack(state);
121 err = invoke_psci_fn(fn, power_state, entry_point, 0);
122 return psci_to_linux_errno(err);
123}
124
125static int psci_cpu_off(struct psci_power_state state)
126{
127 int err;
128 u32 fn, power_state;
129
130 fn = psci_function_id[PSCI_FN_CPU_OFF];
131 power_state = psci_power_state_pack(state);
132 err = invoke_psci_fn(fn, power_state, 0, 0);
133 return psci_to_linux_errno(err);
134}
135
136static int psci_cpu_on(unsigned long cpuid, unsigned long entry_point)
137{
138 int err;
139 u32 fn;
140
141 fn = psci_function_id[PSCI_FN_CPU_ON];
142 err = invoke_psci_fn(fn, cpuid, entry_point, 0);
143 return psci_to_linux_errno(err);
144}
145
146static int psci_migrate(unsigned long cpuid)
147{
148 int err;
149 u32 fn;
150
151 fn = psci_function_id[PSCI_FN_MIGRATE];
152 err = invoke_psci_fn(fn, cpuid, 0, 0);
153 return psci_to_linux_errno(err);
154}
155
156static const struct of_device_id psci_of_match[] __initconst = {
157 { .compatible = "arm,psci", },
158 {},
159};
160
161static int __init psci_init(void)
162{
163 struct device_node *np;
164 const char *method;
165 u32 id;
166
167 np = of_find_matching_node(NULL, psci_of_match);
168 if (!np)
169 return 0;
170
171 pr_info("probing function IDs from device-tree\n");
172
173 if (of_property_read_string(np, "method", &method)) {
174 pr_warning("missing \"method\" property\n");
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 goto out_put_node;
185 }
186
187 if (!of_property_read_u32(np, "cpu_suspend", &id)) {
188 psci_function_id[PSCI_FN_CPU_SUSPEND] = id;
189 psci_ops.cpu_suspend = psci_cpu_suspend;
190 }
191
192 if (!of_property_read_u32(np, "cpu_off", &id)) {
193 psci_function_id[PSCI_FN_CPU_OFF] = id;
194 psci_ops.cpu_off = psci_cpu_off;
195 }
196
197 if (!of_property_read_u32(np, "cpu_on", &id)) {
198 psci_function_id[PSCI_FN_CPU_ON] = id;
199 psci_ops.cpu_on = psci_cpu_on;
200 }
201
202 if (!of_property_read_u32(np, "migrate", &id)) {
203 psci_function_id[PSCI_FN_MIGRATE] = id;
204 psci_ops.migrate = psci_migrate;
205 }
206
207out_put_node:
208 of_node_put(np);
209 return 0;
210}
211early_initcall(psci_init);
212
