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 #include <linux/suspend.h>
24 
25 #include <uapi/linux/psci.h>
26 
27 #include <asm/cputype.h>
28 #include <asm/system_misc.h>
29 #include <asm/smp_plat.h>
30 #include <asm/suspend.h>
31 
32 /*
33  * While a 64-bit OS can make calls with SMC32 calling conventions, for some
34  * calls it is necessary to use SMC64 to pass or return 64-bit values.
35  * For such calls PSCI_FN_NATIVE(version, name) will choose the appropriate
36  * (native-width) function ID.
37  */
38 #ifdef CONFIG_64BIT
39 #define PSCI_FN_NATIVE(version, name)	PSCI_##version##_FN64_##name
40 #else
41 #define PSCI_FN_NATIVE(version, name)	PSCI_##version##_FN_##name
42 #endif
43 
44 /*
45  * The CPU any Trusted OS is resident on. The trusted OS may reject CPU_OFF
46  * calls to its resident CPU, so we must avoid issuing those. We never migrate
47  * a Trusted OS even if it claims to be capable of migration -- doing so will
48  * require cooperation with a Trusted OS driver.
49  */
50 static int resident_cpu = -1;
51 
psci_tos_resident_on(int cpu)52 bool psci_tos_resident_on(int cpu)
53 {
54 	return cpu == resident_cpu;
55 }
56 
57 struct psci_operations psci_ops;
58 
59 typedef unsigned long (psci_fn)(unsigned long, unsigned long,
60 				unsigned long, unsigned long);
61 asmlinkage psci_fn __invoke_psci_fn_hvc;
62 asmlinkage psci_fn __invoke_psci_fn_smc;
63 static psci_fn *invoke_psci_fn;
64 
65 enum psci_function {
66 	PSCI_FN_CPU_SUSPEND,
67 	PSCI_FN_CPU_ON,
68 	PSCI_FN_CPU_OFF,
69 	PSCI_FN_MIGRATE,
70 	PSCI_FN_MAX,
71 };
72 
73 static u32 psci_function_id[PSCI_FN_MAX];
74 
75 #define PSCI_0_2_POWER_STATE_MASK		\
76 				(PSCI_0_2_POWER_STATE_ID_MASK | \
77 				PSCI_0_2_POWER_STATE_TYPE_MASK | \
78 				PSCI_0_2_POWER_STATE_AFFL_MASK)
79 
80 #define PSCI_1_0_EXT_POWER_STATE_MASK		\
81 				(PSCI_1_0_EXT_POWER_STATE_ID_MASK | \
82 				PSCI_1_0_EXT_POWER_STATE_TYPE_MASK)
83 
84 static u32 psci_cpu_suspend_feature;
85 
psci_has_ext_power_state(void)86 static inline bool psci_has_ext_power_state(void)
87 {
88 	return psci_cpu_suspend_feature &
89 				PSCI_1_0_FEATURES_CPU_SUSPEND_PF_MASK;
90 }
91 
psci_power_state_loses_context(u32 state)92 bool psci_power_state_loses_context(u32 state)
93 {
94 	const u32 mask = psci_has_ext_power_state() ?
95 					PSCI_1_0_EXT_POWER_STATE_TYPE_MASK :
96 					PSCI_0_2_POWER_STATE_TYPE_MASK;
97 
98 	return state & mask;
99 }
100 
psci_power_state_is_valid(u32 state)101 bool psci_power_state_is_valid(u32 state)
102 {
103 	const u32 valid_mask = psci_has_ext_power_state() ?
104 			       PSCI_1_0_EXT_POWER_STATE_MASK :
105 			       PSCI_0_2_POWER_STATE_MASK;
106 
107 	return !(state & ~valid_mask);
108 }
109 
psci_to_linux_errno(int errno)110 static int psci_to_linux_errno(int errno)
111 {
112 	switch (errno) {
113 	case PSCI_RET_SUCCESS:
114 		return 0;
115 	case PSCI_RET_NOT_SUPPORTED:
116 		return -EOPNOTSUPP;
117 	case PSCI_RET_INVALID_PARAMS:
118 	case PSCI_RET_INVALID_ADDRESS:
119 		return -EINVAL;
120 	case PSCI_RET_DENIED:
121 		return -EPERM;
122 	};
123 
124 	return -EINVAL;
125 }
126 
psci_get_version(void)127 static u32 psci_get_version(void)
128 {
129 	return invoke_psci_fn(PSCI_0_2_FN_PSCI_VERSION, 0, 0, 0);
130 }
131 
psci_cpu_suspend(u32 state,unsigned long entry_point)132 static int psci_cpu_suspend(u32 state, unsigned long entry_point)
133 {
134 	int err;
135 	u32 fn;
136 
137 	fn = psci_function_id[PSCI_FN_CPU_SUSPEND];
138 	err = invoke_psci_fn(fn, state, entry_point, 0);
139 	return psci_to_linux_errno(err);
140 }
141 
psci_cpu_off(u32 state)142 static int psci_cpu_off(u32 state)
143 {
144 	int err;
145 	u32 fn;
146 
147 	fn = psci_function_id[PSCI_FN_CPU_OFF];
148 	err = invoke_psci_fn(fn, state, 0, 0);
149 	return psci_to_linux_errno(err);
150 }
151 
psci_cpu_on(unsigned long cpuid,unsigned long entry_point)152 static int psci_cpu_on(unsigned long cpuid, unsigned long entry_point)
153 {
154 	int err;
155 	u32 fn;
156 
157 	fn = psci_function_id[PSCI_FN_CPU_ON];
158 	err = invoke_psci_fn(fn, cpuid, entry_point, 0);
159 	return psci_to_linux_errno(err);
160 }
161 
psci_migrate(unsigned long cpuid)162 static int psci_migrate(unsigned long cpuid)
163 {
164 	int err;
165 	u32 fn;
166 
167 	fn = psci_function_id[PSCI_FN_MIGRATE];
168 	err = invoke_psci_fn(fn, cpuid, 0, 0);
169 	return psci_to_linux_errno(err);
170 }
171 
psci_affinity_info(unsigned long target_affinity,unsigned long lowest_affinity_level)172 static int psci_affinity_info(unsigned long target_affinity,
173 		unsigned long lowest_affinity_level)
174 {
175 	return invoke_psci_fn(PSCI_FN_NATIVE(0_2, AFFINITY_INFO),
176 			      target_affinity, lowest_affinity_level, 0);
177 }
178 
psci_migrate_info_type(void)179 static int psci_migrate_info_type(void)
180 {
181 	return invoke_psci_fn(PSCI_0_2_FN_MIGRATE_INFO_TYPE, 0, 0, 0);
182 }
183 
psci_migrate_info_up_cpu(void)184 static unsigned long psci_migrate_info_up_cpu(void)
185 {
186 	return invoke_psci_fn(PSCI_FN_NATIVE(0_2, MIGRATE_INFO_UP_CPU),
187 			      0, 0, 0);
188 }
189 
get_set_conduit_method(struct device_node * np)190 static int get_set_conduit_method(struct device_node *np)
191 {
192 	const char *method;
193 
194 	pr_info("probing for conduit method from DT.\n");
195 
196 	if (of_property_read_string(np, "method", &method)) {
197 		pr_warn("missing \"method\" property\n");
198 		return -ENXIO;
199 	}
200 
201 	if (!strcmp("hvc", method)) {
202 		invoke_psci_fn = __invoke_psci_fn_hvc;
203 	} else if (!strcmp("smc", method)) {
204 		invoke_psci_fn = __invoke_psci_fn_smc;
205 	} else {
206 		pr_warn("invalid \"method\" property: %s\n", method);
207 		return -EINVAL;
208 	}
209 	return 0;
210 }
211 
psci_sys_reset(enum reboot_mode reboot_mode,const char * cmd)212 static void psci_sys_reset(enum reboot_mode reboot_mode, const char *cmd)
213 {
214 	invoke_psci_fn(PSCI_0_2_FN_SYSTEM_RESET, 0, 0, 0);
215 }
216 
psci_sys_poweroff(void)217 static void psci_sys_poweroff(void)
218 {
219 	invoke_psci_fn(PSCI_0_2_FN_SYSTEM_OFF, 0, 0, 0);
220 }
221 
psci_features(u32 psci_func_id)222 static int __init psci_features(u32 psci_func_id)
223 {
224 	return invoke_psci_fn(PSCI_1_0_FN_PSCI_FEATURES,
225 			      psci_func_id, 0, 0);
226 }
227 
psci_system_suspend(unsigned long unused)228 static int psci_system_suspend(unsigned long unused)
229 {
230 	return invoke_psci_fn(PSCI_FN_NATIVE(1_0, SYSTEM_SUSPEND),
231 			      virt_to_phys(cpu_resume), 0, 0);
232 }
233 
psci_system_suspend_enter(suspend_state_t state)234 static int psci_system_suspend_enter(suspend_state_t state)
235 {
236 	return cpu_suspend(0, psci_system_suspend);
237 }
238 
239 static const struct platform_suspend_ops psci_suspend_ops = {
240 	.valid          = suspend_valid_only_mem,
241 	.enter          = psci_system_suspend_enter,
242 };
243 
psci_init_system_suspend(void)244 static void __init psci_init_system_suspend(void)
245 {
246 	int ret;
247 
248 	if (!IS_ENABLED(CONFIG_SUSPEND))
249 		return;
250 
251 	ret = psci_features(PSCI_FN_NATIVE(1_0, SYSTEM_SUSPEND));
252 
253 	if (ret != PSCI_RET_NOT_SUPPORTED)
254 		suspend_set_ops(&psci_suspend_ops);
255 }
256 
psci_init_cpu_suspend(void)257 static void __init psci_init_cpu_suspend(void)
258 {
259 	int feature = psci_features(psci_function_id[PSCI_FN_CPU_SUSPEND]);
260 
261 	if (feature != PSCI_RET_NOT_SUPPORTED)
262 		psci_cpu_suspend_feature = feature;
263 }
264 
265 /*
266  * Detect the presence of a resident Trusted OS which may cause CPU_OFF to
267  * return DENIED (which would be fatal).
268  */
psci_init_migrate(void)269 static void __init psci_init_migrate(void)
270 {
271 	unsigned long cpuid;
272 	int type, cpu = -1;
273 
274 	type = psci_ops.migrate_info_type();
275 
276 	if (type == PSCI_0_2_TOS_MP) {
277 		pr_info("Trusted OS migration not required\n");
278 		return;
279 	}
280 
281 	if (type == PSCI_RET_NOT_SUPPORTED) {
282 		pr_info("MIGRATE_INFO_TYPE not supported.\n");
283 		return;
284 	}
285 
286 	if (type != PSCI_0_2_TOS_UP_MIGRATE &&
287 	    type != PSCI_0_2_TOS_UP_NO_MIGRATE) {
288 		pr_err("MIGRATE_INFO_TYPE returned unknown type (%d)\n", type);
289 		return;
290 	}
291 
292 	cpuid = psci_migrate_info_up_cpu();
293 	if (cpuid & ~MPIDR_HWID_BITMASK) {
294 		pr_warn("MIGRATE_INFO_UP_CPU reported invalid physical ID (0x%lx)\n",
295 			cpuid);
296 		return;
297 	}
298 
299 	cpu = get_logical_index(cpuid);
300 	resident_cpu = cpu >= 0 ? cpu : -1;
301 
302 	pr_info("Trusted OS resident on physical CPU 0x%lx\n", cpuid);
303 }
304 
psci_0_2_set_functions(void)305 static void __init psci_0_2_set_functions(void)
306 {
307 	pr_info("Using standard PSCI v0.2 function IDs\n");
308 	psci_function_id[PSCI_FN_CPU_SUSPEND] =
309 					PSCI_FN_NATIVE(0_2, CPU_SUSPEND);
310 	psci_ops.cpu_suspend = psci_cpu_suspend;
311 
312 	psci_function_id[PSCI_FN_CPU_OFF] = PSCI_0_2_FN_CPU_OFF;
313 	psci_ops.cpu_off = psci_cpu_off;
314 
315 	psci_function_id[PSCI_FN_CPU_ON] = PSCI_FN_NATIVE(0_2, CPU_ON);
316 	psci_ops.cpu_on = psci_cpu_on;
317 
318 	psci_function_id[PSCI_FN_MIGRATE] = PSCI_FN_NATIVE(0_2, MIGRATE);
319 	psci_ops.migrate = psci_migrate;
320 
321 	psci_ops.affinity_info = psci_affinity_info;
322 
323 	psci_ops.migrate_info_type = psci_migrate_info_type;
324 
325 	arm_pm_restart = psci_sys_reset;
326 
327 	pm_power_off = psci_sys_poweroff;
328 }
329 
330 /*
331  * Probe function for PSCI firmware versions >= 0.2
332  */
psci_probe(void)333 static int __init psci_probe(void)
334 {
335 	u32 ver = psci_get_version();
336 
337 	pr_info("PSCIv%d.%d detected in firmware.\n",
338 			PSCI_VERSION_MAJOR(ver),
339 			PSCI_VERSION_MINOR(ver));
340 
341 	if (PSCI_VERSION_MAJOR(ver) == 0 && PSCI_VERSION_MINOR(ver) < 2) {
342 		pr_err("Conflicting PSCI version detected.\n");
343 		return -EINVAL;
344 	}
345 
346 	psci_0_2_set_functions();
347 
348 	psci_init_migrate();
349 
350 	if (PSCI_VERSION_MAJOR(ver) >= 1) {
351 		psci_init_cpu_suspend();
352 		psci_init_system_suspend();
353 	}
354 
355 	return 0;
356 }
357 
358 typedef int (*psci_initcall_t)(const struct device_node *);
359 
360 /*
361  * PSCI init function for PSCI versions >=0.2
362  *
363  * Probe based on PSCI PSCI_VERSION function
364  */
psci_0_2_init(struct device_node * np)365 static int __init psci_0_2_init(struct device_node *np)
366 {
367 	int err;
368 
369 	err = get_set_conduit_method(np);
370 
371 	if (err)
372 		goto out_put_node;
373 	/*
374 	 * Starting with v0.2, the PSCI specification introduced a call
375 	 * (PSCI_VERSION) that allows probing the firmware version, so
376 	 * that PSCI function IDs and version specific initialization
377 	 * can be carried out according to the specific version reported
378 	 * by firmware
379 	 */
380 	err = psci_probe();
381 
382 out_put_node:
383 	of_node_put(np);
384 	return err;
385 }
386 
387 /*
388  * PSCI < v0.2 get PSCI Function IDs via DT.
389  */
psci_0_1_init(struct device_node * np)390 static int __init psci_0_1_init(struct device_node *np)
391 {
392 	u32 id;
393 	int err;
394 
395 	err = get_set_conduit_method(np);
396 
397 	if (err)
398 		goto out_put_node;
399 
400 	pr_info("Using PSCI v0.1 Function IDs from DT\n");
401 
402 	if (!of_property_read_u32(np, "cpu_suspend", &id)) {
403 		psci_function_id[PSCI_FN_CPU_SUSPEND] = id;
404 		psci_ops.cpu_suspend = psci_cpu_suspend;
405 	}
406 
407 	if (!of_property_read_u32(np, "cpu_off", &id)) {
408 		psci_function_id[PSCI_FN_CPU_OFF] = id;
409 		psci_ops.cpu_off = psci_cpu_off;
410 	}
411 
412 	if (!of_property_read_u32(np, "cpu_on", &id)) {
413 		psci_function_id[PSCI_FN_CPU_ON] = id;
414 		psci_ops.cpu_on = psci_cpu_on;
415 	}
416 
417 	if (!of_property_read_u32(np, "migrate", &id)) {
418 		psci_function_id[PSCI_FN_MIGRATE] = id;
419 		psci_ops.migrate = psci_migrate;
420 	}
421 
422 out_put_node:
423 	of_node_put(np);
424 	return err;
425 }
426 
427 static const struct of_device_id const psci_of_match[] __initconst = {
428 	{ .compatible = "arm,psci",	.data = psci_0_1_init},
429 	{ .compatible = "arm,psci-0.2",	.data = psci_0_2_init},
430 	{ .compatible = "arm,psci-1.0",	.data = psci_0_2_init},
431 	{},
432 };
433 
psci_dt_init(void)434 int __init psci_dt_init(void)
435 {
436 	struct device_node *np;
437 	const struct of_device_id *matched_np;
438 	psci_initcall_t init_fn;
439 
440 	np = of_find_matching_node_and_match(NULL, psci_of_match, &matched_np);
441 
442 	if (!np)
443 		return -ENODEV;
444 
445 	init_fn = (psci_initcall_t)matched_np->data;
446 	return init_fn(np);
447 }
448 
449 #ifdef CONFIG_ACPI
450 /*
451  * We use PSCI 0.2+ when ACPI is deployed on ARM64 and it's
452  * explicitly clarified in SBBR
453  */
psci_acpi_init(void)454 int __init psci_acpi_init(void)
455 {
456 	if (!acpi_psci_present()) {
457 		pr_info("is not implemented in ACPI.\n");
458 		return -EOPNOTSUPP;
459 	}
460 
461 	pr_info("probing for conduit method from ACPI.\n");
462 
463 	if (acpi_psci_use_hvc())
464 		invoke_psci_fn = __invoke_psci_fn_hvc;
465 	else
466 		invoke_psci_fn = __invoke_psci_fn_smc;
467 
468 	return psci_probe();
469 }
470 #endif
471