1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Copyright (C) 2017 Masahiro Yamada <yamada.masahiro@socionext.com>
4  *
5  * Based on drivers/firmware/psci.c from Linux:
6  * Copyright (C) 2015 ARM Limited
7  */
8 
9 #include <command.h>
10 #include <dm.h>
11 #include <efi_loader.h>
12 #include <irq_func.h>
13 #include <linker_lists.h>
14 #include <log.h>
15 #include <sysreset.h>
16 #include <asm/system.h>
17 #include <dm/device-internal.h>
18 #include <dm/lists.h>
19 #include <linux/arm-smccc.h>
20 #include <linux/delay.h>
21 #include <linux/errno.h>
22 #include <linux/libfdt.h>
23 #include <linux/printk.h>
24 #include <linux/psci.h>
25 #include <power-domain-uclass.h>
26 
27 #define DRIVER_NAME "psci"
28 
29 #define PSCI_METHOD_HVC 1
30 #define PSCI_METHOD_SMC 2
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 #if defined(CONFIG_ARM64)
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 #if CONFIG_IS_ENABLED(EFI_LOADER)
45 int __efi_runtime_data psci_method;
46 #else
47 int psci_method __section(".data");
48 #endif
49 
invoke_psci_fn(unsigned long function_id,unsigned long arg0,unsigned long arg1,unsigned long arg2)50 unsigned long __efi_runtime invoke_psci_fn
51 		(unsigned long function_id, unsigned long arg0,
52 		 unsigned long arg1, unsigned long arg2)
53 {
54 	struct arm_smccc_res res;
55 
56 	/*
57 	 * In the __efi_runtime we need to avoid the switch statement. In some
58 	 * cases the compiler creates lookup tables to implement switch. These
59 	 * tables are not correctly relocated when SetVirtualAddressMap is
60 	 * called.
61 	 */
62 	if (psci_method == PSCI_METHOD_SMC)
63 		arm_smccc_smc(function_id, arg0, arg1, arg2, 0, 0, 0, 0, &res);
64 	else if (psci_method == PSCI_METHOD_HVC)
65 		arm_smccc_hvc(function_id, arg0, arg1, arg2, 0, 0, 0, 0, &res);
66 	else
67 		res.a0 = PSCI_RET_DISABLED;
68 	return res.a0;
69 }
70 
request_psci_features(u32 psci_func_id)71 static int request_psci_features(u32 psci_func_id)
72 {
73 	return invoke_psci_fn(PSCI_1_0_FN_PSCI_FEATURES,
74 			      psci_func_id, 0, 0);
75 }
76 
psci_0_2_get_version(void)77 static u32 psci_0_2_get_version(void)
78 {
79 	return invoke_psci_fn(PSCI_0_2_FN_PSCI_VERSION, 0, 0, 0);
80 }
81 
psci_is_system_reset2_supported(void)82 static bool psci_is_system_reset2_supported(void)
83 {
84 	int ret;
85 	u32 ver;
86 
87 	ver = psci_0_2_get_version();
88 
89 	if (PSCI_VERSION_MAJOR(ver) >= 1) {
90 		ret = request_psci_features(PSCI_FN_NATIVE(1_1,
91 							   SYSTEM_RESET2));
92 
93 		if (ret != PSCI_RET_NOT_SUPPORTED)
94 			return true;
95 	}
96 
97 	return false;
98 }
99 
smccc_invoke_hvc(unsigned long a0,unsigned long a1,unsigned long a2,unsigned long a3,unsigned long a4,unsigned long a5,unsigned long a6,unsigned long a7,struct arm_smccc_res * res)100 static void smccc_invoke_hvc(unsigned long a0, unsigned long a1,
101 			     unsigned long a2, unsigned long a3,
102 			     unsigned long a4, unsigned long a5,
103 			     unsigned long a6, unsigned long a7,
104 			     struct arm_smccc_res *res)
105 {
106 	arm_smccc_hvc(a0, a1, a2, a3, a4, a5, a6, a7, res);
107 }
108 
smccc_invoke_smc(unsigned long a0,unsigned long a1,unsigned long a2,unsigned long a3,unsigned long a4,unsigned long a5,unsigned long a6,unsigned long a7,struct arm_smccc_res * res)109 static void smccc_invoke_smc(unsigned long a0, unsigned long a1,
110 			     unsigned long a2, unsigned long a3,
111 			     unsigned long a4, unsigned long a5,
112 			     unsigned long a6, unsigned long a7,
113 			     struct arm_smccc_res *res)
114 {
115 	arm_smccc_smc(a0, a1, a2, a3, a4, a5, a6, a7, res);
116 }
117 
bind_smccc_features(struct udevice * dev,int psci_method)118 static int bind_smccc_features(struct udevice *dev, int psci_method)
119 {
120 	struct psci_plat_data *pdata = dev_get_plat(dev);
121 	struct arm_smccc_feature *feature;
122 	size_t feature_cnt, n;
123 
124 	if (!IS_ENABLED(CONFIG_ARM_SMCCC_FEATURES))
125 		return 0;
126 
127 	/*
128 	 * SMCCC features discovery invoke SMCCC standard function ID
129 	 * ARM_SMCCC_ARCH_FEATURES but this sequence requires that this
130 	 * standard ARM_SMCCC_ARCH_FEATURES function ID itself is supported.
131 	 * It is queried here with invoking PSCI_FEATURES known available
132 	 * from PSCI 1.0.
133 	 */
134 	if (!device_is_compatible(dev, "arm,psci-1.0") ||
135 	    PSCI_VERSION_MAJOR(psci_0_2_get_version()) == 0)
136 		return 0;
137 
138 	if (request_psci_features(ARM_SMCCC_VERSION) ==
139 	    PSCI_RET_NOT_SUPPORTED)
140 		return 0;
141 
142 	if (invoke_psci_fn(ARM_SMCCC_VERSION, 0, 0, 0) < ARM_SMCCC_VERSION_1_1)
143 		return 0;
144 
145 	if (psci_method == PSCI_METHOD_HVC)
146 		pdata->invoke_fn = smccc_invoke_hvc;
147 	else
148 		pdata->invoke_fn = smccc_invoke_smc;
149 
150 	feature_cnt = ll_entry_count(struct arm_smccc_feature, arm_smccc_feature);
151 	feature = ll_entry_start(struct arm_smccc_feature, arm_smccc_feature);
152 
153 	for (n = 0; n < feature_cnt; n++, feature++) {
154 		const char *drv_name = feature->driver_name;
155 		struct udevice *dev2;
156 		int ret;
157 
158 		if (!feature->is_supported || !feature->is_supported(pdata->invoke_fn))
159 			continue;
160 
161 		ret = device_bind_driver(dev, drv_name, drv_name, &dev2);
162 		if (ret) {
163 			pr_warn("%s was not bound: %d, ignore\n", drv_name, ret);
164 			continue;
165 		}
166 
167 		dev_set_parent_plat(dev2, dev_get_plat(dev));
168 	}
169 
170 	return 0;
171 }
172 
psci_bind(struct udevice * dev)173 static int psci_bind(struct udevice *dev)
174 {
175 #if IS_ENABLED(CONFIG_POWER_DOMAIN)
176 	ofnode node;
177 #endif
178 
179 	/* No SYSTEM_RESET support for PSCI 0.1 */
180 	if (device_is_compatible(dev, "arm,psci-0.2") ||
181 	    device_is_compatible(dev, "arm,psci-1.0")) {
182 		int ret;
183 
184 		/* bind psci-sysreset optionally */
185 		ret = device_bind_driver(dev, "psci-sysreset", "psci-sysreset",
186 					 NULL);
187 		if (ret)
188 			pr_debug("PSCI System Reset was not bound.\n");
189 	}
190 
191 	/* From PSCI v1.0 onward we can discover services through ARM_SMCCC_FEATURE */
192 	if (IS_ENABLED(CONFIG_ARM_SMCCC_FEATURES) && device_is_compatible(dev, "arm,psci-1.0"))
193 		dev_or_flags(dev, DM_FLAG_PROBE_AFTER_BIND);
194 
195 	/* Bind power-domain subnodes */
196 #if IS_ENABLED(CONFIG_POWER_DOMAIN)
197 	dev_for_each_subnode(node, dev) {
198 		if (device_bind_driver_to_node(dev, "psci_power_domain",
199 					       ofnode_get_name(node),
200 					       node, NULL))
201 			pr_warn("failed to bind %s\n", ofnode_get_name(node));
202 	}
203 #endif
204 
205 	return 0;
206 }
207 
psci_probe(struct udevice * dev)208 static int psci_probe(struct udevice *dev)
209 {
210 	const char *method;
211 
212 #if defined(CONFIG_ARM64)
213 	if (current_el() == 3)
214 		return -EINVAL;
215 #endif
216 
217 	method = ofnode_read_string(dev_ofnode(dev), "method");
218 	if (!method) {
219 		pr_warn("missing \"method\" property\n");
220 		return -ENXIO;
221 	}
222 
223 	if (!strcmp("hvc", method)) {
224 		psci_method = PSCI_METHOD_HVC;
225 	} else if (!strcmp("smc", method)) {
226 		psci_method = PSCI_METHOD_SMC;
227 	} else {
228 		pr_warn("invalid \"method\" property: %s\n", method);
229 		return -EINVAL;
230 	}
231 
232 	return bind_smccc_features(dev, psci_method);
233 }
234 
235 /**
236  * void do_psci_probe() - probe PSCI firmware driver
237  *
238  * Ensure that psci_method is initialized.
239  */
do_psci_probe(void)240 static void __maybe_unused do_psci_probe(void)
241 {
242 	struct udevice *dev;
243 
244 	uclass_get_device_by_name(UCLASS_FIRMWARE, DRIVER_NAME, &dev);
245 }
246 
247 #if IS_ENABLED(CONFIG_EFI_LOADER) && IS_ENABLED(CONFIG_PSCI_RESET)
efi_reset_system_init(void)248 efi_status_t efi_reset_system_init(void)
249 {
250 	do_psci_probe();
251 	return EFI_SUCCESS;
252 }
253 
efi_reset_system(enum efi_reset_type reset_type,efi_status_t reset_status,unsigned long data_size,void * reset_data)254 void __efi_runtime EFIAPI efi_reset_system(enum efi_reset_type reset_type,
255 					   efi_status_t reset_status,
256 					   unsigned long data_size,
257 					   void *reset_data)
258 {
259 	if (reset_type == EFI_RESET_COLD ||
260 	    reset_type == EFI_RESET_WARM ||
261 	    reset_type == EFI_RESET_PLATFORM_SPECIFIC) {
262 		invoke_psci_fn(PSCI_0_2_FN_SYSTEM_RESET, 0, 0, 0);
263 	} else if (reset_type == EFI_RESET_SHUTDOWN) {
264 		invoke_psci_fn(PSCI_0_2_FN_SYSTEM_OFF, 0, 0, 0);
265 	}
266 	while (1)
267 		;
268 }
269 #endif /* IS_ENABLED(CONFIG_EFI_LOADER) && IS_ENABLED(CONFIG_PSCI_RESET) */
270 
271 #ifdef CONFIG_PSCI_RESET
reset_misc(void)272 void reset_misc(void)
273 {
274 	do_psci_probe();
275 	invoke_psci_fn(PSCI_0_2_FN_SYSTEM_RESET, 0, 0, 0);
276 }
277 #endif /* CONFIG_PSCI_RESET */
278 
psci_sys_reset(u32 type)279 void psci_sys_reset(u32 type)
280 {
281 	bool reset2_supported;
282 
283 	do_psci_probe();
284 
285 	reset2_supported = psci_is_system_reset2_supported();
286 
287 	if (type == SYSRESET_WARM && reset2_supported) {
288 		/*
289 		 * reset_type[31] = 0 (architectural)
290 		 * reset_type[30:0] = 0 (SYSTEM_WARM_RESET)
291 		 * cookie = 0 (ignored by the implementation)
292 		 */
293 		invoke_psci_fn(PSCI_FN_NATIVE(1_1, SYSTEM_RESET2), 0, 0, 0);
294 	} else {
295 		invoke_psci_fn(PSCI_0_2_FN_SYSTEM_RESET, 0, 0, 0);
296 	}
297 }
298 
psci_sys_poweroff(void)299 void psci_sys_poweroff(void)
300 {
301 	do_psci_probe();
302 
303 	invoke_psci_fn(PSCI_0_2_FN_SYSTEM_OFF, 0, 0, 0);
304 }
305 
306 #if IS_ENABLED(CONFIG_CMD_POWEROFF) && !IS_ENABLED(CONFIG_SYSRESET_CMD_POWEROFF)
do_poweroff(struct cmd_tbl * cmdtp,int flag,int argc,char * const argv[])307 int do_poweroff(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[])
308 {
309 	do_psci_probe();
310 
311 	puts("poweroff ...\n");
312 	udelay(50000); /* wait 50 ms */
313 
314 	disable_interrupts();
315 	invoke_psci_fn(PSCI_0_2_FN_SYSTEM_OFF, 0, 0, 0);
316 	enable_interrupts();
317 
318 	log_err("Power off not supported on this platform\n");
319 	return CMD_RET_FAILURE;
320 }
321 #endif
322 
323 static const struct udevice_id psci_of_match[] = {
324 	{ .compatible = "arm,psci" },
325 	{ .compatible = "arm,psci-0.2" },
326 	{ .compatible = "arm,psci-1.0" },
327 	{},
328 };
329 
330 U_BOOT_DRIVER(psci) = {
331 	.name = DRIVER_NAME,
332 	.id = UCLASS_FIRMWARE,
333 	.of_match = psci_of_match,
334 	.bind = psci_bind,
335 	.probe = psci_probe,
336 #ifdef CONFIG_ARM_SMCCC_FEATURES
337 	.plat_auto = sizeof(struct psci_plat_data),
338 #endif
339 	.flags = DM_FLAG_PRE_RELOC,
340 };
341 
342 #if IS_ENABLED(CONFIG_POWER_DOMAIN)
343 /* Accept #power-domain-cells == 0 */
psci_power_domain_xlate(struct power_domain * power_domain,struct ofnode_phandle_args * args)344 static int psci_power_domain_xlate(struct power_domain *power_domain,
345 				   struct ofnode_phandle_args *args)
346 {
347 	return args->args_count == 0 ? 0 : -EINVAL;
348 }
349 
350 static const struct power_domain_ops psci_power_ops = {
351 	.of_xlate = psci_power_domain_xlate,
352 };
353 
psci_power_domain_probe(struct udevice * dev)354 static int psci_power_domain_probe(struct udevice *dev)
355 {
356 	return 0;
357 }
358 
359 U_BOOT_DRIVER(psci_power_domain) = {
360 	.name = "psci_power_domain",
361 	.id = UCLASS_POWER_DOMAIN,
362 	.ops = &psci_power_ops,
363 	.probe = psci_power_domain_probe,
364 	.flags = DM_FLAG_PRE_RELOC,
365 };
366 #endif
367