[deliverable/linux.git] / drivers / firmware / psci.c

/*
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * Copyright (C) 2015 ARM Limited
 */

#define pr_fmt(fmt) "psci: " fmt

#include <linux/errno.h>
#include <linux/linkage.h>
#include <linux/of.h>
#include <linux/pm.h>
#include <linux/printk.h>
#include <linux/psci.h>
#include <linux/reboot.h>

#include <uapi/linux/psci.h>

#include <asm/cputype.h>
#include <asm/system_misc.h>
#include <asm/smp_plat.h>

/*
 * While a 64-bit OS can make calls with SMC32 calling conventions, for some
 * calls it is necessary to use SMC64 to pass or return 64-bit values. For such
 * calls PSCI_0_2_FN_NATIVE(x) will choose the appropriate (native-width)
 * function ID.
 */
#ifdef CONFIG_64BIT
#define PSCI_0_2_FN_NATIVE(name)	PSCI_0_2_FN64_##name
#else
#define PSCI_0_2_FN_NATIVE(name)	PSCI_0_2_FN_##name
#endif

/*
 * The CPU any Trusted OS is resident on. The trusted OS may reject CPU_OFF
 * calls to its resident CPU, so we must avoid issuing those. We never migrate
 * a Trusted OS even if it claims to be capable of migration -- doing so will
 * require cooperation with a Trusted OS driver.
 */
static int resident_cpu = -1;

bool psci_tos_resident_on(int cpu)
{
	return cpu == resident_cpu;
}

struct psci_operations psci_ops;

typedef unsigned long (psci_fn)(unsigned long, unsigned long,
				unsigned long, unsigned long);
asmlinkage psci_fn __invoke_psci_fn_hvc;
asmlinkage psci_fn __invoke_psci_fn_smc;
static psci_fn *invoke_psci_fn;

enum psci_function {
	PSCI_FN_CPU_SUSPEND,
	PSCI_FN_CPU_ON,
	PSCI_FN_CPU_OFF,
	PSCI_FN_MIGRATE,
	PSCI_FN_MAX,
};

static u32 psci_function_id[PSCI_FN_MAX];

static int psci_to_linux_errno(int errno)
{
	switch (errno) {
	case PSCI_RET_SUCCESS:
		return 0;
	case PSCI_RET_NOT_SUPPORTED:
		return -EOPNOTSUPP;
	case PSCI_RET_INVALID_PARAMS:
	case PSCI_RET_INVALID_ADDRESS:
		return -EINVAL;
	case PSCI_RET_DENIED:
		return -EPERM;
	};

	return -EINVAL;
}

static u32 psci_get_version(void)
{
	return invoke_psci_fn(PSCI_0_2_FN_PSCI_VERSION, 0, 0, 0);
}

static int psci_cpu_suspend(u32 state, unsigned long entry_point)
{
	int err;
	u32 fn;

	fn = psci_function_id[PSCI_FN_CPU_SUSPEND];
	err = invoke_psci_fn(fn, state, entry_point, 0);
	return psci_to_linux_errno(err);
}

static int psci_cpu_off(u32 state)
{
	int err;
	u32 fn;

	fn = psci_function_id[PSCI_FN_CPU_OFF];
	err = invoke_psci_fn(fn, state, 0, 0);
	return psci_to_linux_errno(err);
}

static int psci_cpu_on(unsigned long cpuid, unsigned long entry_point)
{
	int err;
	u32 fn;

	fn = psci_function_id[PSCI_FN_CPU_ON];
	err = invoke_psci_fn(fn, cpuid, entry_point, 0);
	return psci_to_linux_errno(err);
}

static int psci_migrate(unsigned long cpuid)
{
	int err;
	u32 fn;

	fn = psci_function_id[PSCI_FN_MIGRATE];
	err = invoke_psci_fn(fn, cpuid, 0, 0);
	return psci_to_linux_errno(err);
}

static int psci_affinity_info(unsigned long target_affinity,
		unsigned long lowest_affinity_level)
{
	return invoke_psci_fn(PSCI_0_2_FN_NATIVE(AFFINITY_INFO),
			      target_affinity, lowest_affinity_level, 0);
}

static int psci_migrate_info_type(void)
{
	return invoke_psci_fn(PSCI_0_2_FN_MIGRATE_INFO_TYPE, 0, 0, 0);
}

static unsigned long psci_migrate_info_up_cpu(void)
{
	return invoke_psci_fn(PSCI_0_2_FN_NATIVE(MIGRATE_INFO_UP_CPU),
			      0, 0, 0);
}

static int get_set_conduit_method(struct device_node *np)
{
	const char *method;

	pr_info("probing for conduit method from DT.\n");

	if (of_property_read_string(np, "method", &method)) {
		pr_warn("missing \"method\" property\n");
		return -ENXIO;
	}

	if (!strcmp("hvc", method)) {
		invoke_psci_fn = __invoke_psci_fn_hvc;
	} else if (!strcmp("smc", method)) {
		invoke_psci_fn = __invoke_psci_fn_smc;
	} else {
		pr_warn("invalid \"method\" property: %s\n", method);
		return -EINVAL;
	}
	return 0;
}

static void psci_sys_reset(enum reboot_mode reboot_mode, const char *cmd)
{
	invoke_psci_fn(PSCI_0_2_FN_SYSTEM_RESET, 0, 0, 0);
}

static void psci_sys_poweroff(void)
{
	invoke_psci_fn(PSCI_0_2_FN_SYSTEM_OFF, 0, 0, 0);
}

/*
 * Detect the presence of a resident Trusted OS which may cause CPU_OFF to
 * return DENIED (which would be fatal).
 */
static void __init psci_init_migrate(void)
{
	unsigned long cpuid;
	int type, cpu = -1;

	type = psci_ops.migrate_info_type();

	if (type == PSCI_0_2_TOS_MP) {
		pr_info("Trusted OS migration not required\n");
		return;
	}

	if (type == PSCI_RET_NOT_SUPPORTED) {
		pr_info("MIGRATE_INFO_TYPE not supported.\n");
		return;
	}

	if (type != PSCI_0_2_TOS_UP_MIGRATE &&
	    type != PSCI_0_2_TOS_UP_NO_MIGRATE) {
		pr_err("MIGRATE_INFO_TYPE returned unknown type (%d)\n", type);
		return;
	}

	cpuid = psci_migrate_info_up_cpu();
	if (cpuid & ~MPIDR_HWID_BITMASK) {
		pr_warn("MIGRATE_INFO_UP_CPU reported invalid physical ID (0x%lx)\n",
			cpuid);
		return;
	}

	cpu = get_logical_index(cpuid);
	resident_cpu = cpu >= 0 ? cpu : -1;

	pr_info("Trusted OS resident on physical CPU 0x%lx\n", cpuid);
}

static void __init psci_0_2_set_functions(void)
{
	pr_info("Using standard PSCI v0.2 function IDs\n");
	psci_function_id[PSCI_FN_CPU_SUSPEND] = PSCI_0_2_FN_NATIVE(CPU_SUSPEND);
	psci_ops.cpu_suspend = psci_cpu_suspend;

	psci_function_id[PSCI_FN_CPU_OFF] = PSCI_0_2_FN_CPU_OFF;
	psci_ops.cpu_off = psci_cpu_off;

	psci_function_id[PSCI_FN_CPU_ON] = PSCI_0_2_FN_NATIVE(CPU_ON);
	psci_ops.cpu_on = psci_cpu_on;

	psci_function_id[PSCI_FN_MIGRATE] = PSCI_0_2_FN_NATIVE(MIGRATE);
	psci_ops.migrate = psci_migrate;

	psci_ops.affinity_info = psci_affinity_info;

	psci_ops.migrate_info_type = psci_migrate_info_type;

	arm_pm_restart = psci_sys_reset;

	pm_power_off = psci_sys_poweroff;
}

/*
 * Probe function for PSCI firmware versions >= 0.2
 */
static int __init psci_probe(void)
{
	u32 ver = psci_get_version();

	pr_info("PSCIv%d.%d detected in firmware.\n",
			PSCI_VERSION_MAJOR(ver),
			PSCI_VERSION_MINOR(ver));

	if (PSCI_VERSION_MAJOR(ver) == 0 && PSCI_VERSION_MINOR(ver) < 2) {
		pr_err("Conflicting PSCI version detected.\n");
		return -EINVAL;
	}

	psci_0_2_set_functions();

	psci_init_migrate();

	return 0;
}

typedef int (*psci_initcall_t)(const struct device_node *);

/*
 * PSCI init function for PSCI versions >=0.2
 *
 * Probe based on PSCI PSCI_VERSION function
 */
static int __init psci_0_2_init(struct device_node *np)
{
	int err;

	err = get_set_conduit_method(np);

	if (err)
		goto out_put_node;
	/*
	 * Starting with v0.2, the PSCI specification introduced a call
	 * (PSCI_VERSION) that allows probing the firmware version, so
	 * that PSCI function IDs and version specific initialization
	 * can be carried out according to the specific version reported
	 * by firmware
	 */
	err = psci_probe();

out_put_node:
	of_node_put(np);
	return err;
}

/*
 * PSCI < v0.2 get PSCI Function IDs via DT.
 */
static int __init psci_0_1_init(struct device_node *np)
{
	u32 id;
	int err;

	err = get_set_conduit_method(np);

	if (err)
		goto out_put_node;

	pr_info("Using PSCI v0.1 Function IDs from DT\n");

	if (!of_property_read_u32(np, "cpu_suspend", &id)) {
		psci_function_id[PSCI_FN_CPU_SUSPEND] = id;
		psci_ops.cpu_suspend = psci_cpu_suspend;
	}

	if (!of_property_read_u32(np, "cpu_off", &id)) {
		psci_function_id[PSCI_FN_CPU_OFF] = id;
		psci_ops.cpu_off = psci_cpu_off;
	}

	if (!of_property_read_u32(np, "cpu_on", &id)) {
		psci_function_id[PSCI_FN_CPU_ON] = id;
		psci_ops.cpu_on = psci_cpu_on;
	}

	if (!of_property_read_u32(np, "migrate", &id)) {
		psci_function_id[PSCI_FN_MIGRATE] = id;
		psci_ops.migrate = psci_migrate;
	}

out_put_node:
	of_node_put(np);
	return err;
}

static const struct of_device_id const psci_of_match[] __initconst = {
	{ .compatible = "arm,psci",	.data = psci_0_1_init},
	{ .compatible = "arm,psci-0.2",	.data = psci_0_2_init},
	{},
};

int __init psci_dt_init(void)
{
	struct device_node *np;
	const struct of_device_id *matched_np;
	psci_initcall_t init_fn;

	np = of_find_matching_node_and_match(NULL, psci_of_match, &matched_np);

	if (!np)
		return -ENODEV;

	init_fn = (psci_initcall_t)matched_np->data;
	return init_fn(np);
}

#ifdef CONFIG_ACPI
/*
 * We use PSCI 0.2+ when ACPI is deployed on ARM64 and it's
 * explicitly clarified in SBBR
 */
int __init psci_acpi_init(void)
{
	if (!acpi_psci_present()) {
		pr_info("is not implemented in ACPI.\n");
		return -EOPNOTSUPP;
	}

	pr_info("probing for conduit method from ACPI.\n");

	if (acpi_psci_use_hvc())
		invoke_psci_fn = __invoke_psci_fn_hvc;
	else
		invoke_psci_fn = __invoke_psci_fn_smc;

	return psci_probe();
}
#endif
Commit	Line	Data
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
5211df00 MR	30	/*
	31	* While a 64-bit OS can make calls with SMC32 calling conventions, for some
	32	* calls it is necessary to use SMC64 to pass or return 64-bit values. For such
	33	* calls PSCI_0_2_FN_NATIVE(x) will choose the appropriate (native-width)
	34	* function ID.
	35	*/
	36	#ifdef CONFIG_64BIT
	37	#define PSCI_0_2_FN_NATIVE(name) PSCI_0_2_FN64_##name
	38	#else
	39	#define PSCI_0_2_FN_NATIVE(name) PSCI_0_2_FN_##name
	40	#endif
	41
bff60792 MR	42	/*
	43	* The CPU any Trusted OS is resident on. The trusted OS may reject CPU_OFF
	44	* calls to its resident CPU, so we must avoid issuing those. We never migrate
	45	* a Trusted OS even if it claims to be capable of migration -- doing so will
	46	* require cooperation with a Trusted OS driver.
	47	*/
	48	static int resident_cpu = -1;
	49
	50	bool psci_tos_resident_on(int cpu)
	51	{
	52	return cpu == resident_cpu;
	53	}
	54
	55	struct psci_operations psci_ops;
	56
	57	typedef unsigned long (psci_fn)(unsigned long, unsigned long,
	58	unsigned long, unsigned long);
	59	asmlinkage psci_fn __invoke_psci_fn_hvc;
	60	asmlinkage psci_fn __invoke_psci_fn_smc;
	61	static psci_fn *invoke_psci_fn;
	62
	63	enum psci_function {
	64	PSCI_FN_CPU_SUSPEND,
	65	PSCI_FN_CPU_ON,
	66	PSCI_FN_CPU_OFF,
	67	PSCI_FN_MIGRATE,
	68	PSCI_FN_MAX,
	69	};
	70
	71	static u32 psci_function_id[PSCI_FN_MAX];
	72
	73	static int psci_to_linux_errno(int errno)
	74	{
	75	switch (errno) {
	76	case PSCI_RET_SUCCESS:
	77	return 0;
	78	case PSCI_RET_NOT_SUPPORTED:
	79	return -EOPNOTSUPP;
	80	case PSCI_RET_INVALID_PARAMS:
2217d7c6	81	case PSCI_RET_INVALID_ADDRESS:
bff60792 MR	82	return -EINVAL;
	83	case PSCI_RET_DENIED:
	84	return -EPERM;
	85	};
	86
	87	return -EINVAL;
	88	}
	89
	90	static u32 psci_get_version(void)
	91	{
	92	return invoke_psci_fn(PSCI_0_2_FN_PSCI_VERSION, 0, 0, 0);
	93	}
	94
	95	static int psci_cpu_suspend(u32 state, unsigned long entry_point)
	96	{
	97	int err;
	98	u32 fn;
	99
	100	fn = psci_function_id[PSCI_FN_CPU_SUSPEND];
	101	err = invoke_psci_fn(fn, state, entry_point, 0);
	102	return psci_to_linux_errno(err);
	103	}
	104
	105	static int psci_cpu_off(u32 state)
	106	{
	107	int err;
	108	u32 fn;
	109
	110	fn = psci_function_id[PSCI_FN_CPU_OFF];
	111	err = invoke_psci_fn(fn, state, 0, 0);
	112	return psci_to_linux_errno(err);
	113	}
	114
	115	static int psci_cpu_on(unsigned long cpuid, unsigned long entry_point)
	116	{
	117	int err;
	118	u32 fn;
	119
	120	fn = psci_function_id[PSCI_FN_CPU_ON];
	121	err = invoke_psci_fn(fn, cpuid, entry_point, 0);
	122	return psci_to_linux_errno(err);
	123	}
	124
	125	static int psci_migrate(unsigned long cpuid)
	126	{
	127	int err;
	128	u32 fn;
	129
	130	fn = psci_function_id[PSCI_FN_MIGRATE];
	131	err = invoke_psci_fn(fn, cpuid, 0, 0);
	132	return psci_to_linux_errno(err);
	133	}
	134
	135	static int psci_affinity_info(unsigned long target_affinity,
	136	unsigned long lowest_affinity_level)
	137	{
5211df00 MR	138	return invoke_psci_fn(PSCI_0_2_FN_NATIVE(AFFINITY_INFO),
5211df00 MR	139	target_affinity, lowest_affinity_level, 0);
bff60792 MR	140	}
	141
	142	static int psci_migrate_info_type(void)
	143	{
	144	return invoke_psci_fn(PSCI_0_2_FN_MIGRATE_INFO_TYPE, 0, 0, 0);
	145	}
	146
	147	static unsigned long psci_migrate_info_up_cpu(void)
	148	{
5211df00 MR	149	return invoke_psci_fn(PSCI_0_2_FN_NATIVE(MIGRATE_INFO_UP_CPU),
5211df00 MR	150	0, 0, 0);
bff60792 MR	151	}
	152
	153	static int get_set_conduit_method(struct device_node *np)
	154	{
	155	const char *method;
	156
	157	pr_info("probing for conduit method from DT.\n");
	158
	159	if (of_property_read_string(np, "method", &method)) {
	160	pr_warn("missing \"method\" property\n");
	161	return -ENXIO;
	162	}
	163
	164	if (!strcmp("hvc", method)) {
	165	invoke_psci_fn = __invoke_psci_fn_hvc;
	166	} else if (!strcmp("smc", method)) {
	167	invoke_psci_fn = __invoke_psci_fn_smc;
	168	} else {
	169	pr_warn("invalid \"method\" property: %s\n", method);
	170	return -EINVAL;
	171	}
	172	return 0;
	173	}
	174
	175	static void psci_sys_reset(enum reboot_mode reboot_mode, const char *cmd)
	176	{
	177	invoke_psci_fn(PSCI_0_2_FN_SYSTEM_RESET, 0, 0, 0);
	178	}
	179
	180	static void psci_sys_poweroff(void)
	181	{
	182	invoke_psci_fn(PSCI_0_2_FN_SYSTEM_OFF, 0, 0, 0);
	183	}
	184
	185	/*
	186	* Detect the presence of a resident Trusted OS which may cause CPU_OFF to
	187	* return DENIED (which would be fatal).
	188	*/
	189	static void __init psci_init_migrate(void)
	190	{
	191	unsigned long cpuid;
	192	int type, cpu = -1;
	193
	194	type = psci_ops.migrate_info_type();
	195
	196	if (type == PSCI_0_2_TOS_MP) {
	197	pr_info("Trusted OS migration not required\n");
	198	return;
	199	}
	200
	201	if (type == PSCI_RET_NOT_SUPPORTED) {
	202	pr_info("MIGRATE_INFO_TYPE not supported.\n");
	203	return;
	204	}
	205
	206	if (type != PSCI_0_2_TOS_UP_MIGRATE &&
	207	type != PSCI_0_2_TOS_UP_NO_MIGRATE) {
	208	pr_err("MIGRATE_INFO_TYPE returned unknown type (%d)\n", type);
	209	return;
	210	}
	211
	212	cpuid = psci_migrate_info_up_cpu();
	213	if (cpuid & ~MPIDR_HWID_BITMASK) {
	214	pr_warn("MIGRATE_INFO_UP_CPU reported invalid physical ID (0x%lx)\n",
215	cpuid);
216	return;
217	}
218
219	cpu = get_logical_index(cpuid);
220	resident_cpu = cpu >= 0 ? cpu : -1;
221
222	pr_info("Trusted OS resident on physical CPU 0x%lx\n", cpuid);
223	}
224
225	static void __init psci_0_2_set_functions(void)
226	{
227	pr_info("Using standard PSCI v0.2 function IDs\n");
5211df00	228	psci_function_id[PSCI_FN_CPU_SUSPEND] = PSCI_0_2_FN_NATIVE(CPU_SUSPEND);
bff60792 MR	229	psci_ops.cpu_suspend = psci_cpu_suspend;
	230
	231	psci_function_id[PSCI_FN_CPU_OFF] = PSCI_0_2_FN_CPU_OFF;
	232	psci_ops.cpu_off = psci_cpu_off;
	233
5211df00	234	psci_function_id[PSCI_FN_CPU_ON] = PSCI_0_2_FN_NATIVE(CPU_ON);
bff60792 MR	235	psci_ops.cpu_on = psci_cpu_on;
bff60792 MR	236
5211df00	237	psci_function_id[PSCI_FN_MIGRATE] = PSCI_0_2_FN_NATIVE(MIGRATE);
bff60792 MR	238	psci_ops.migrate = psci_migrate;
	239
	240	psci_ops.affinity_info = psci_affinity_info;
	241
	242	psci_ops.migrate_info_type = psci_migrate_info_type;
	243
	244	arm_pm_restart = psci_sys_reset;
	245
	246	pm_power_off = psci_sys_poweroff;
	247	}
	248
	249	/*
	250	* Probe function for PSCI firmware versions >= 0.2
	251	*/
	252	static int __init psci_probe(void)
	253	{
	254	u32 ver = psci_get_version();
	255
	256	pr_info("PSCIv%d.%d detected in firmware.\n",
	257	PSCI_VERSION_MAJOR(ver),
	258	PSCI_VERSION_MINOR(ver));
	259
	260	if (PSCI_VERSION_MAJOR(ver) == 0 && PSCI_VERSION_MINOR(ver) < 2) {
	261	pr_err("Conflicting PSCI version detected.\n");
	262	return -EINVAL;
	263	}
	264
	265	psci_0_2_set_functions();
	266
	267	psci_init_migrate();
	268
	269	return 0;
	270	}
	271
	272	typedef int (psci_initcall_t)(const struct device_node );
	273
	274	/*
	275	* PSCI init function for PSCI versions >=0.2
	276	*
	277	* Probe based on PSCI PSCI_VERSION function
	278	*/
	279	static int __init psci_0_2_init(struct device_node *np)
	280	{
	281	int err;
	282
	283	err = get_set_conduit_method(np);
	284
	285	if (err)
	286	goto out_put_node;
	287	/*
	288	* Starting with v0.2, the PSCI specification introduced a call
	289	* (PSCI_VERSION) that allows probing the firmware version, so
	290	* that PSCI function IDs and version specific initialization
	291	* can be carried out according to the specific version reported
	292	* by firmware
	293	*/
	294	err = psci_probe();
	295
	296	out_put_node:
	297	of_node_put(np);
	298	return err;
	299	}
	300
	301	/*
302	* PSCI < v0.2 get PSCI Function IDs via DT.
303	*/
304	static int __init psci_0_1_init(struct device_node *np)
305	{
306	u32 id;
307	int err;
308
309	err = get_set_conduit_method(np);
310
311	if (err)
312	goto out_put_node;
313
314	pr_info("Using PSCI v0.1 Function IDs from DT\n");
315
316	if (!of_property_read_u32(np, "cpu_suspend", &id)) {
317	psci_function_id[PSCI_FN_CPU_SUSPEND] = id;
318	psci_ops.cpu_suspend = psci_cpu_suspend;
319	}
320
321	if (!of_property_read_u32(np, "cpu_off", &id)) {
322	psci_function_id[PSCI_FN_CPU_OFF] = id;
323	psci_ops.cpu_off = psci_cpu_off;
324	}
325
326	if (!of_property_read_u32(np, "cpu_on", &id)) {
327	psci_function_id[PSCI_FN_CPU_ON] = id;
328	psci_ops.cpu_on = psci_cpu_on;
329	}
330
331	if (!of_property_read_u32(np, "migrate", &id)) {
332	psci_function_id[PSCI_FN_MIGRATE] = id;
333	psci_ops.migrate = psci_migrate;
334	}
335
336	out_put_node:
337	of_node_put(np);
338	return err;
339	}
340
c706c7eb	341	static const struct of_device_id const psci_of_match[] __initconst = {
bff60792 MR	342	{ .compatible = "arm,psci", .data = psci_0_1_init},
	343	{ .compatible = "arm,psci-0.2", .data = psci_0_2_init},
	344	{},
	345	};
	346
	347	int __init psci_dt_init(void)
	348	{
	349	struct device_node *np;
	350	const struct of_device_id *matched_np;
	351	psci_initcall_t init_fn;
	352
	353	np = of_find_matching_node_and_match(NULL, psci_of_match, &matched_np);
	354
	355	if (!np)
	356	return -ENODEV;
	357
	358	init_fn = (psci_initcall_t)matched_np->data;
	359	return init_fn(np);
	360	}
	361
	362	#ifdef CONFIG_ACPI
	363	/*
	364	* We use PSCI 0.2+ when ACPI is deployed on ARM64 and it's
	365	* explicitly clarified in SBBR
	366	*/
	367	int __init psci_acpi_init(void)
	368	{
	369	if (!acpi_psci_present()) {
	370	pr_info("is not implemented in ACPI.\n");
	371	return -EOPNOTSUPP;
	372	}
	373
	374	pr_info("probing for conduit method from ACPI.\n");
	375
	376	if (acpi_psci_use_hvc())
	377	invoke_psci_fn = __invoke_psci_fn_hvc;
	378	else
	379	invoke_psci_fn = __invoke_psci_fn_smc;
	380
	381	return psci_probe();
	382	}
	383	#endif