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bff60792 MR |
1 | /* |
2 | * This program is free software; you can redistribute it and/or modify | |
3 | * it under the terms of the GNU General Public License version 2 as | |
4 | * published by the Free Software Foundation. | |
5 | * | |
6 | * This program is distributed in the hope that it will be useful, | |
7 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
8 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
9 | * GNU General Public License for more details. | |
10 | * | |
11 | * Copyright (C) 2015 ARM Limited | |
12 | */ | |
13 | ||
14 | #define pr_fmt(fmt) "psci: " fmt | |
15 | ||
16 | #include <linux/errno.h> | |
17 | #include <linux/linkage.h> | |
18 | #include <linux/of.h> | |
19 | #include <linux/pm.h> | |
20 | #include <linux/printk.h> | |
21 | #include <linux/psci.h> | |
22 | #include <linux/reboot.h> | |
23 | ||
24 | #include <uapi/linux/psci.h> | |
25 | ||
26 | #include <asm/cputype.h> | |
27 | #include <asm/system_misc.h> | |
28 | #include <asm/smp_plat.h> | |
29 | ||
30 | /* | |
31 | * The CPU any Trusted OS is resident on. The trusted OS may reject CPU_OFF | |
32 | * calls to its resident CPU, so we must avoid issuing those. We never migrate | |
33 | * a Trusted OS even if it claims to be capable of migration -- doing so will | |
34 | * require cooperation with a Trusted OS driver. | |
35 | */ | |
36 | static int resident_cpu = -1; | |
37 | ||
38 | bool psci_tos_resident_on(int cpu) | |
39 | { | |
40 | return cpu == resident_cpu; | |
41 | } | |
42 | ||
43 | struct psci_operations psci_ops; | |
44 | ||
45 | typedef unsigned long (psci_fn)(unsigned long, unsigned long, | |
46 | unsigned long, unsigned long); | |
47 | asmlinkage psci_fn __invoke_psci_fn_hvc; | |
48 | asmlinkage psci_fn __invoke_psci_fn_smc; | |
49 | static psci_fn *invoke_psci_fn; | |
50 | ||
51 | enum psci_function { | |
52 | PSCI_FN_CPU_SUSPEND, | |
53 | PSCI_FN_CPU_ON, | |
54 | PSCI_FN_CPU_OFF, | |
55 | PSCI_FN_MIGRATE, | |
56 | PSCI_FN_MAX, | |
57 | }; | |
58 | ||
59 | static u32 psci_function_id[PSCI_FN_MAX]; | |
60 | ||
61 | static int psci_to_linux_errno(int errno) | |
62 | { | |
63 | switch (errno) { | |
64 | case PSCI_RET_SUCCESS: | |
65 | return 0; | |
66 | case PSCI_RET_NOT_SUPPORTED: | |
67 | return -EOPNOTSUPP; | |
68 | case PSCI_RET_INVALID_PARAMS: | |
69 | return -EINVAL; | |
70 | case PSCI_RET_DENIED: | |
71 | return -EPERM; | |
72 | }; | |
73 | ||
74 | return -EINVAL; | |
75 | } | |
76 | ||
77 | static u32 psci_get_version(void) | |
78 | { | |
79 | return invoke_psci_fn(PSCI_0_2_FN_PSCI_VERSION, 0, 0, 0); | |
80 | } | |
81 | ||
82 | static int psci_cpu_suspend(u32 state, unsigned long entry_point) | |
83 | { | |
84 | int err; | |
85 | u32 fn; | |
86 | ||
87 | fn = psci_function_id[PSCI_FN_CPU_SUSPEND]; | |
88 | err = invoke_psci_fn(fn, state, entry_point, 0); | |
89 | return psci_to_linux_errno(err); | |
90 | } | |
91 | ||
92 | static int psci_cpu_off(u32 state) | |
93 | { | |
94 | int err; | |
95 | u32 fn; | |
96 | ||
97 | fn = psci_function_id[PSCI_FN_CPU_OFF]; | |
98 | err = invoke_psci_fn(fn, state, 0, 0); | |
99 | return psci_to_linux_errno(err); | |
100 | } | |
101 | ||
102 | static int psci_cpu_on(unsigned long cpuid, unsigned long entry_point) | |
103 | { | |
104 | int err; | |
105 | u32 fn; | |
106 | ||
107 | fn = psci_function_id[PSCI_FN_CPU_ON]; | |
108 | err = invoke_psci_fn(fn, cpuid, entry_point, 0); | |
109 | return psci_to_linux_errno(err); | |
110 | } | |
111 | ||
112 | static int psci_migrate(unsigned long cpuid) | |
113 | { | |
114 | int err; | |
115 | u32 fn; | |
116 | ||
117 | fn = psci_function_id[PSCI_FN_MIGRATE]; | |
118 | err = invoke_psci_fn(fn, cpuid, 0, 0); | |
119 | return psci_to_linux_errno(err); | |
120 | } | |
121 | ||
122 | static int psci_affinity_info(unsigned long target_affinity, | |
123 | unsigned long lowest_affinity_level) | |
124 | { | |
125 | return invoke_psci_fn(PSCI_0_2_FN64_AFFINITY_INFO, target_affinity, | |
126 | lowest_affinity_level, 0); | |
127 | } | |
128 | ||
129 | static int psci_migrate_info_type(void) | |
130 | { | |
131 | return invoke_psci_fn(PSCI_0_2_FN_MIGRATE_INFO_TYPE, 0, 0, 0); | |
132 | } | |
133 | ||
134 | static unsigned long psci_migrate_info_up_cpu(void) | |
135 | { | |
136 | return invoke_psci_fn(PSCI_0_2_FN64_MIGRATE_INFO_UP_CPU, 0, 0, 0); | |
137 | } | |
138 | ||
139 | static int get_set_conduit_method(struct device_node *np) | |
140 | { | |
141 | const char *method; | |
142 | ||
143 | pr_info("probing for conduit method from DT.\n"); | |
144 | ||
145 | if (of_property_read_string(np, "method", &method)) { | |
146 | pr_warn("missing \"method\" property\n"); | |
147 | return -ENXIO; | |
148 | } | |
149 | ||
150 | if (!strcmp("hvc", method)) { | |
151 | invoke_psci_fn = __invoke_psci_fn_hvc; | |
152 | } else if (!strcmp("smc", method)) { | |
153 | invoke_psci_fn = __invoke_psci_fn_smc; | |
154 | } else { | |
155 | pr_warn("invalid \"method\" property: %s\n", method); | |
156 | return -EINVAL; | |
157 | } | |
158 | return 0; | |
159 | } | |
160 | ||
161 | static void psci_sys_reset(enum reboot_mode reboot_mode, const char *cmd) | |
162 | { | |
163 | invoke_psci_fn(PSCI_0_2_FN_SYSTEM_RESET, 0, 0, 0); | |
164 | } | |
165 | ||
166 | static void psci_sys_poweroff(void) | |
167 | { | |
168 | invoke_psci_fn(PSCI_0_2_FN_SYSTEM_OFF, 0, 0, 0); | |
169 | } | |
170 | ||
171 | /* | |
172 | * Detect the presence of a resident Trusted OS which may cause CPU_OFF to | |
173 | * return DENIED (which would be fatal). | |
174 | */ | |
175 | static void __init psci_init_migrate(void) | |
176 | { | |
177 | unsigned long cpuid; | |
178 | int type, cpu = -1; | |
179 | ||
180 | type = psci_ops.migrate_info_type(); | |
181 | ||
182 | if (type == PSCI_0_2_TOS_MP) { | |
183 | pr_info("Trusted OS migration not required\n"); | |
184 | return; | |
185 | } | |
186 | ||
187 | if (type == PSCI_RET_NOT_SUPPORTED) { | |
188 | pr_info("MIGRATE_INFO_TYPE not supported.\n"); | |
189 | return; | |
190 | } | |
191 | ||
192 | if (type != PSCI_0_2_TOS_UP_MIGRATE && | |
193 | type != PSCI_0_2_TOS_UP_NO_MIGRATE) { | |
194 | pr_err("MIGRATE_INFO_TYPE returned unknown type (%d)\n", type); | |
195 | return; | |
196 | } | |
197 | ||
198 | cpuid = psci_migrate_info_up_cpu(); | |
199 | if (cpuid & ~MPIDR_HWID_BITMASK) { | |
200 | pr_warn("MIGRATE_INFO_UP_CPU reported invalid physical ID (0x%lx)\n", | |
201 | cpuid); | |
202 | return; | |
203 | } | |
204 | ||
205 | cpu = get_logical_index(cpuid); | |
206 | resident_cpu = cpu >= 0 ? cpu : -1; | |
207 | ||
208 | pr_info("Trusted OS resident on physical CPU 0x%lx\n", cpuid); | |
209 | } | |
210 | ||
211 | static void __init psci_0_2_set_functions(void) | |
212 | { | |
213 | pr_info("Using standard PSCI v0.2 function IDs\n"); | |
214 | psci_function_id[PSCI_FN_CPU_SUSPEND] = PSCI_0_2_FN64_CPU_SUSPEND; | |
215 | psci_ops.cpu_suspend = psci_cpu_suspend; | |
216 | ||
217 | psci_function_id[PSCI_FN_CPU_OFF] = PSCI_0_2_FN_CPU_OFF; | |
218 | psci_ops.cpu_off = psci_cpu_off; | |
219 | ||
220 | psci_function_id[PSCI_FN_CPU_ON] = PSCI_0_2_FN64_CPU_ON; | |
221 | psci_ops.cpu_on = psci_cpu_on; | |
222 | ||
223 | psci_function_id[PSCI_FN_MIGRATE] = PSCI_0_2_FN64_MIGRATE; | |
224 | psci_ops.migrate = psci_migrate; | |
225 | ||
226 | psci_ops.affinity_info = psci_affinity_info; | |
227 | ||
228 | psci_ops.migrate_info_type = psci_migrate_info_type; | |
229 | ||
230 | arm_pm_restart = psci_sys_reset; | |
231 | ||
232 | pm_power_off = psci_sys_poweroff; | |
233 | } | |
234 | ||
235 | /* | |
236 | * Probe function for PSCI firmware versions >= 0.2 | |
237 | */ | |
238 | static int __init psci_probe(void) | |
239 | { | |
240 | u32 ver = psci_get_version(); | |
241 | ||
242 | pr_info("PSCIv%d.%d detected in firmware.\n", | |
243 | PSCI_VERSION_MAJOR(ver), | |
244 | PSCI_VERSION_MINOR(ver)); | |
245 | ||
246 | if (PSCI_VERSION_MAJOR(ver) == 0 && PSCI_VERSION_MINOR(ver) < 2) { | |
247 | pr_err("Conflicting PSCI version detected.\n"); | |
248 | return -EINVAL; | |
249 | } | |
250 | ||
251 | psci_0_2_set_functions(); | |
252 | ||
253 | psci_init_migrate(); | |
254 | ||
255 | return 0; | |
256 | } | |
257 | ||
258 | typedef int (*psci_initcall_t)(const struct device_node *); | |
259 | ||
260 | /* | |
261 | * PSCI init function for PSCI versions >=0.2 | |
262 | * | |
263 | * Probe based on PSCI PSCI_VERSION function | |
264 | */ | |
265 | static int __init psci_0_2_init(struct device_node *np) | |
266 | { | |
267 | int err; | |
268 | ||
269 | err = get_set_conduit_method(np); | |
270 | ||
271 | if (err) | |
272 | goto out_put_node; | |
273 | /* | |
274 | * Starting with v0.2, the PSCI specification introduced a call | |
275 | * (PSCI_VERSION) that allows probing the firmware version, so | |
276 | * that PSCI function IDs and version specific initialization | |
277 | * can be carried out according to the specific version reported | |
278 | * by firmware | |
279 | */ | |
280 | err = psci_probe(); | |
281 | ||
282 | out_put_node: | |
283 | of_node_put(np); | |
284 | return err; | |
285 | } | |
286 | ||
287 | /* | |
288 | * PSCI < v0.2 get PSCI Function IDs via DT. | |
289 | */ | |
290 | static int __init psci_0_1_init(struct device_node *np) | |
291 | { | |
292 | u32 id; | |
293 | int err; | |
294 | ||
295 | err = get_set_conduit_method(np); | |
296 | ||
297 | if (err) | |
298 | goto out_put_node; | |
299 | ||
300 | pr_info("Using PSCI v0.1 Function IDs from DT\n"); | |
301 | ||
302 | if (!of_property_read_u32(np, "cpu_suspend", &id)) { | |
303 | psci_function_id[PSCI_FN_CPU_SUSPEND] = id; | |
304 | psci_ops.cpu_suspend = psci_cpu_suspend; | |
305 | } | |
306 | ||
307 | if (!of_property_read_u32(np, "cpu_off", &id)) { | |
308 | psci_function_id[PSCI_FN_CPU_OFF] = id; | |
309 | psci_ops.cpu_off = psci_cpu_off; | |
310 | } | |
311 | ||
312 | if (!of_property_read_u32(np, "cpu_on", &id)) { | |
313 | psci_function_id[PSCI_FN_CPU_ON] = id; | |
314 | psci_ops.cpu_on = psci_cpu_on; | |
315 | } | |
316 | ||
317 | if (!of_property_read_u32(np, "migrate", &id)) { | |
318 | psci_function_id[PSCI_FN_MIGRATE] = id; | |
319 | psci_ops.migrate = psci_migrate; | |
320 | } | |
321 | ||
322 | out_put_node: | |
323 | of_node_put(np); | |
324 | return err; | |
325 | } | |
326 | ||
327 | static const struct of_device_id psci_of_match[] __initconst = { | |
328 | { .compatible = "arm,psci", .data = psci_0_1_init}, | |
329 | { .compatible = "arm,psci-0.2", .data = psci_0_2_init}, | |
330 | {}, | |
331 | }; | |
332 | ||
333 | int __init psci_dt_init(void) | |
334 | { | |
335 | struct device_node *np; | |
336 | const struct of_device_id *matched_np; | |
337 | psci_initcall_t init_fn; | |
338 | ||
339 | np = of_find_matching_node_and_match(NULL, psci_of_match, &matched_np); | |
340 | ||
341 | if (!np) | |
342 | return -ENODEV; | |
343 | ||
344 | init_fn = (psci_initcall_t)matched_np->data; | |
345 | return init_fn(np); | |
346 | } | |
347 | ||
348 | #ifdef CONFIG_ACPI | |
349 | /* | |
350 | * We use PSCI 0.2+ when ACPI is deployed on ARM64 and it's | |
351 | * explicitly clarified in SBBR | |
352 | */ | |
353 | int __init psci_acpi_init(void) | |
354 | { | |
355 | if (!acpi_psci_present()) { | |
356 | pr_info("is not implemented in ACPI.\n"); | |
357 | return -EOPNOTSUPP; | |
358 | } | |
359 | ||
360 | pr_info("probing for conduit method from ACPI.\n"); | |
361 | ||
362 | if (acpi_psci_use_hvc()) | |
363 | invoke_psci_fn = __invoke_psci_fn_hvc; | |
364 | else | |
365 | invoke_psci_fn = __invoke_psci_fn_smc; | |
366 | ||
367 | return psci_probe(); | |
368 | } | |
369 | #endif |