[deliverable/linux.git] / arch / arm64 / kernel / 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) 2013 ARM Limited
 *
 * Author: Will Deacon <will.deacon@arm.com>
 */

#define pr_fmt(fmt) "psci: " fmt

#include <linux/init.h>
#include <linux/of.h>
#include <linux/smp.h>
#include <linux/reboot.h>
#include <linux/pm.h>
#include <linux/delay.h>
#include <linux/slab.h>
#include <uapi/linux/psci.h>

#include <asm/compiler.h>
#include <asm/cpu_ops.h>
#include <asm/errno.h>
#include <asm/psci.h>
#include <asm/smp_plat.h>
#include <asm/suspend.h>
#include <asm/system_misc.h>

#define PSCI_POWER_STATE_TYPE_STANDBY		0
#define PSCI_POWER_STATE_TYPE_POWER_DOWN	1

struct psci_power_state {
	u16	id;
	u8	type;
	u8	affinity_level;
};

struct psci_operations {
	int (*cpu_suspend)(struct psci_power_state state,
			   unsigned long entry_point);
	int (*cpu_off)(struct psci_power_state state);
	int (*cpu_on)(unsigned long cpuid, unsigned long entry_point);
	int (*migrate)(unsigned long cpuid);
	int (*affinity_info)(unsigned long target_affinity,
			unsigned long lowest_affinity_level);
	int (*migrate_info_type)(void);
};

static struct psci_operations psci_ops;

static int (*invoke_psci_fn)(u64, u64, u64, u64);
typedef int (*psci_initcall_t)(const struct device_node *);

asmlinkage int __invoke_psci_fn_hvc(u64, u64, u64, u64);
asmlinkage int __invoke_psci_fn_smc(u64, u64, u64, u64);

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

static DEFINE_PER_CPU_READ_MOSTLY(struct psci_power_state *, psci_power_state);

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:
		return -EINVAL;
	case PSCI_RET_DENIED:
		return -EPERM;
	};

	return -EINVAL;
}

static u32 psci_power_state_pack(struct psci_power_state state)
{
	return ((state.id << PSCI_0_2_POWER_STATE_ID_SHIFT)
			& PSCI_0_2_POWER_STATE_ID_MASK) |
		((state.type << PSCI_0_2_POWER_STATE_TYPE_SHIFT)
		 & PSCI_0_2_POWER_STATE_TYPE_MASK) |
		((state.affinity_level << PSCI_0_2_POWER_STATE_AFFL_SHIFT)
		 & PSCI_0_2_POWER_STATE_AFFL_MASK);
}

static void psci_power_state_unpack(u32 power_state,
				    struct psci_power_state *state)
{
	state->id = (power_state & PSCI_0_2_POWER_STATE_ID_MASK) >>
			PSCI_0_2_POWER_STATE_ID_SHIFT;
	state->type = (power_state & PSCI_0_2_POWER_STATE_TYPE_MASK) >>
			PSCI_0_2_POWER_STATE_TYPE_SHIFT;
	state->affinity_level =
			(power_state & PSCI_0_2_POWER_STATE_AFFL_MASK) >>
			PSCI_0_2_POWER_STATE_AFFL_SHIFT;
}

static int psci_get_version(void)
{
	int err;

	err = invoke_psci_fn(PSCI_0_2_FN_PSCI_VERSION, 0, 0, 0);
	return err;
}

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

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

static int psci_cpu_off(struct psci_power_state state)
{
	int err;
	u32 fn, power_state;

	fn = psci_function_id[PSCI_FN_CPU_OFF];
	power_state = psci_power_state_pack(state);
	err = invoke_psci_fn(fn, power_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)
{
	int err;
	u32 fn;

	fn = psci_function_id[PSCI_FN_AFFINITY_INFO];
	err = invoke_psci_fn(fn, target_affinity, lowest_affinity_level, 0);
	return err;
}

static int psci_migrate_info_type(void)
{
	int err;
	u32 fn;

	fn = psci_function_id[PSCI_FN_MIGRATE_INFO_TYPE];
	err = invoke_psci_fn(fn, 0, 0, 0);
	return err;
}

static int __maybe_unused cpu_psci_cpu_init_idle(struct device_node *cpu_node,
						 unsigned int cpu)
{
	int i, ret, count = 0;
	struct psci_power_state *psci_states;
	struct device_node *state_node;

	/*
	 * If the PSCI cpu_suspend function hook has not been initialized
	 * idle states must not be enabled, so bail out
	 */
	if (!psci_ops.cpu_suspend)
		return -EOPNOTSUPP;

	/* Count idle states */
	while ((state_node = of_parse_phandle(cpu_node, "cpu-idle-states",
					      count))) {
		count++;
		of_node_put(state_node);
	}

	if (!count)
		return -ENODEV;

	psci_states = kcalloc(count, sizeof(*psci_states), GFP_KERNEL);
	if (!psci_states)
		return -ENOMEM;

	for (i = 0; i < count; i++) {
		u32 psci_power_state;

		state_node = of_parse_phandle(cpu_node, "cpu-idle-states", i);

		ret = of_property_read_u32(state_node,
					   "arm,psci-suspend-param",
					   &psci_power_state);
		if (ret) {
			pr_warn(" * %s missing arm,psci-suspend-param property\n",
				state_node->full_name);
			of_node_put(state_node);
			goto free_mem;
		}

		of_node_put(state_node);
		pr_debug("psci-power-state %#x index %d\n", psci_power_state,
							    i);
		psci_power_state_unpack(psci_power_state, &psci_states[i]);
	}
	/* Idle states parsed correctly, initialize per-cpu pointer */
	per_cpu(psci_power_state, cpu) = psci_states;
	return 0;

free_mem:
	kfree(psci_states);
	return ret;
}

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);
}

/*
 * PSCI Function IDs for v0.2+ are well defined so use
 * standard values.
 */
static int __init psci_0_2_init(struct device_node *np)
{
	int err, ver;

	err = get_set_conduit_method(np);

	if (err)
		goto out_put_node;

	ver = psci_get_version();

	if (ver == PSCI_RET_NOT_SUPPORTED) {
		/* PSCI v0.2 mandates implementation of PSCI_ID_VERSION. */
		pr_err("PSCI firmware does not comply with the v0.2 spec.\n");
		err = -EOPNOTSUPP;
		goto out_put_node;
	} else {
		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) {
			err = -EINVAL;
			pr_err("Conflicting PSCI version detected.\n");
			goto out_put_node;
		}
	}

	pr_info("Using standard PSCI v0.2 function IDs\n");
	psci_function_id[PSCI_FN_CPU_SUSPEND] = PSCI_0_2_FN64_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_FN64_CPU_ON;
	psci_ops.cpu_on = psci_cpu_on;

	psci_function_id[PSCI_FN_MIGRATE] = PSCI_0_2_FN64_MIGRATE;
	psci_ops.migrate = psci_migrate;

	psci_function_id[PSCI_FN_AFFINITY_INFO] = PSCI_0_2_FN64_AFFINITY_INFO;
	psci_ops.affinity_info = psci_affinity_info;

	psci_function_id[PSCI_FN_MIGRATE_INFO_TYPE] =
		PSCI_0_2_FN_MIGRATE_INFO_TYPE;
	psci_ops.migrate_info_type = psci_migrate_info_type;

	arm_pm_restart = psci_sys_reset;

	pm_power_off = psci_sys_poweroff;

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 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_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_SMP

static int __init cpu_psci_cpu_init(struct device_node *dn, unsigned int cpu)
{
	return 0;
}

static int __init cpu_psci_cpu_prepare(unsigned int cpu)
{
	if (!psci_ops.cpu_on) {
		pr_err("no cpu_on method, not booting CPU%d\n", cpu);
		return -ENODEV;
	}

	return 0;
}

static int cpu_psci_cpu_boot(unsigned int cpu)
{
	int err = psci_ops.cpu_on(cpu_logical_map(cpu), __pa(secondary_entry));
	if (err)
		pr_err("failed to boot CPU%d (%d)\n", cpu, err);

	return err;
}

#ifdef CONFIG_HOTPLUG_CPU
static int cpu_psci_cpu_disable(unsigned int cpu)
{
	/* Fail early if we don't have CPU_OFF support */
	if (!psci_ops.cpu_off)
		return -EOPNOTSUPP;
	return 0;
}

static void cpu_psci_cpu_die(unsigned int cpu)
{
	int ret;
	/*
	 * There are no known implementations of PSCI actually using the
	 * power state field, pass a sensible default for now.
	 */
	struct psci_power_state state = {
		.type = PSCI_POWER_STATE_TYPE_POWER_DOWN,
	};

	ret = psci_ops.cpu_off(state);

	pr_crit("unable to power off CPU%u (%d)\n", cpu, ret);
}

static int cpu_psci_cpu_kill(unsigned int cpu)
{
	int err, i;

	if (!psci_ops.affinity_info)
		return 1;
	/*
	 * cpu_kill could race with cpu_die and we can
	 * potentially end up declaring this cpu undead
	 * while it is dying. So, try again a few times.
	 */

	for (i = 0; i < 10; i++) {
		err = psci_ops.affinity_info(cpu_logical_map(cpu), 0);
		if (err == PSCI_0_2_AFFINITY_LEVEL_OFF) {
			pr_info("CPU%d killed.\n", cpu);
			return 1;
		}

		msleep(10);
		pr_info("Retrying again to check for CPU kill\n");
	}

	pr_warn("CPU%d may not have shut down cleanly (AFFINITY_INFO reports %d)\n",
			cpu, err);
	/* Make op_cpu_kill() fail. */
	return 0;
}
#endif
#endif

static int psci_suspend_finisher(unsigned long index)
{
	struct psci_power_state *state = __this_cpu_read(psci_power_state);

	return psci_ops.cpu_suspend(state[index - 1],
				    virt_to_phys(cpu_resume));
}

static int __maybe_unused cpu_psci_cpu_suspend(unsigned long index)
{
	int ret;
	struct psci_power_state *state = __this_cpu_read(psci_power_state);
	/*
	 * idle state index 0 corresponds to wfi, should never be called
	 * from the cpu_suspend operations
	 */
	if (WARN_ON_ONCE(!index))
		return -EINVAL;

	if (state[index - 1].type == PSCI_POWER_STATE_TYPE_STANDBY)
		ret = psci_ops.cpu_suspend(state[index - 1], 0);
	else
		ret = __cpu_suspend(index, psci_suspend_finisher);

	return ret;
}

const struct cpu_operations cpu_psci_ops = {
	.name		= "psci",
#ifdef CONFIG_CPU_IDLE
	.cpu_init_idle	= cpu_psci_cpu_init_idle,
	.cpu_suspend	= cpu_psci_cpu_suspend,
#endif
#ifdef CONFIG_SMP
	.cpu_init	= cpu_psci_cpu_init,
	.cpu_prepare	= cpu_psci_cpu_prepare,
	.cpu_boot	= cpu_psci_cpu_boot,
#ifdef CONFIG_HOTPLUG_CPU
	.cpu_disable	= cpu_psci_cpu_disable,
	.cpu_die	= cpu_psci_cpu_die,
	.cpu_kill	= cpu_psci_cpu_kill,
#endif
#endif
};
Commit	Line	Data
e790f1de WD	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) 2013 ARM Limited
	12	*
	13	* Author: Will Deacon <will.deacon@arm.com>
	14	*/
	15
	16	#define pr_fmt(fmt) "psci: " fmt
	17
	18	#include <linux/init.h>
	19	#include <linux/of.h>
00ef54bb	20	#include <linux/smp.h>
e71246a2 AC	21	#include <linux/reboot.h>
e71246a2 AC	22	#include <linux/pm.h>
c814ca02	23	#include <linux/delay.h>
18910ab0	24	#include <linux/slab.h>
e71246a2	25	#include <uapi/linux/psci.h>
e790f1de WD	26
e790f1de WD	27	#include <asm/compiler.h>
cd1aebf5	28	#include <asm/cpu_ops.h>
e790f1de WD	29	#include <asm/errno.h>
e790f1de WD	30	#include <asm/psci.h>
00ef54bb	31	#include <asm/smp_plat.h>
18910ab0	32	#include <asm/suspend.h>
e71246a2	33	#include <asm/system_misc.h>
e790f1de	34
00ef54bb MR	35	#define PSCI_POWER_STATE_TYPE_STANDBY 0
	36	#define PSCI_POWER_STATE_TYPE_POWER_DOWN 1
	37
	38	struct psci_power_state {
	39	u16 id;
	40	u8 type;
	41	u8 affinity_level;
	42	};
	43
	44	struct psci_operations {
	45	int (*cpu_suspend)(struct psci_power_state state,
	46	unsigned long entry_point);
	47	int (*cpu_off)(struct psci_power_state state);
	48	int (*cpu_on)(unsigned long cpuid, unsigned long entry_point);
	49	int (*migrate)(unsigned long cpuid);
e71246a2 AC	50	int (*affinity_info)(unsigned long target_affinity,
	51	unsigned long lowest_affinity_level);
	52	int (*migrate_info_type)(void);
00ef54bb MR	53	};
	54
	55	static struct psci_operations psci_ops;
e790f1de WD	56
e790f1de WD	57	static int (*invoke_psci_fn)(u64, u64, u64, u64);
e71246a2	58	typedef int (psci_initcall_t)(const struct device_node );
e790f1de	59
f5e0a12c WD	60	asmlinkage int __invoke_psci_fn_hvc(u64, u64, u64, u64);
	61	asmlinkage int __invoke_psci_fn_smc(u64, u64, u64, u64);
	62
e790f1de WD	63	enum psci_function {
	64	PSCI_FN_CPU_SUSPEND,
	65	PSCI_FN_CPU_ON,
	66	PSCI_FN_CPU_OFF,
	67	PSCI_FN_MIGRATE,
e71246a2 AC	68	PSCI_FN_AFFINITY_INFO,
e71246a2 AC	69	PSCI_FN_MIGRATE_INFO_TYPE,
e790f1de WD	70	PSCI_FN_MAX,
	71	};
	72
18910ab0 LP	73	static DEFINE_PER_CPU_READ_MOSTLY(struct psci_power_state *, psci_power_state);
18910ab0 LP	74
e790f1de WD	75	static u32 psci_function_id[PSCI_FN_MAX];
e790f1de WD	76
e790f1de WD	77	static int psci_to_linux_errno(int errno)
	78	{
	79	switch (errno) {
	80	case PSCI_RET_SUCCESS:
	81	return 0;
e71246a2	82	case PSCI_RET_NOT_SUPPORTED:
e790f1de	83	return -EOPNOTSUPP;
e71246a2	84	case PSCI_RET_INVALID_PARAMS:
e790f1de	85	return -EINVAL;
e71246a2	86	case PSCI_RET_DENIED:
e790f1de WD	87	return -EPERM;
	88	};
	89
	90	return -EINVAL;
	91	}
	92
e790f1de WD	93	static u32 psci_power_state_pack(struct psci_power_state state)
e790f1de WD	94	{
e71246a2 AC	95	return ((state.id << PSCI_0_2_POWER_STATE_ID_SHIFT)
	96	& PSCI_0_2_POWER_STATE_ID_MASK) \|
	97	((state.type << PSCI_0_2_POWER_STATE_TYPE_SHIFT)
	98	& PSCI_0_2_POWER_STATE_TYPE_MASK) \|
	99	((state.affinity_level << PSCI_0_2_POWER_STATE_AFFL_SHIFT)
	100	& PSCI_0_2_POWER_STATE_AFFL_MASK);
e790f1de WD	101	}
e790f1de WD	102
18910ab0 LP	103	static void psci_power_state_unpack(u32 power_state,
	104	struct psci_power_state *state)
	105	{
	106	state->id = (power_state & PSCI_0_2_POWER_STATE_ID_MASK) >>
	107	PSCI_0_2_POWER_STATE_ID_SHIFT;
	108	state->type = (power_state & PSCI_0_2_POWER_STATE_TYPE_MASK) >>
	109	PSCI_0_2_POWER_STATE_TYPE_SHIFT;
	110	state->affinity_level =
	111	(power_state & PSCI_0_2_POWER_STATE_AFFL_MASK) >>
	112	PSCI_0_2_POWER_STATE_AFFL_SHIFT;
	113	}
	114
e71246a2 AC	115	static int psci_get_version(void)
	116	{
	117	int err;
	118
	119	err = invoke_psci_fn(PSCI_0_2_FN_PSCI_VERSION, 0, 0, 0);
	120	return err;
	121	}
	122
e790f1de WD	123	static int psci_cpu_suspend(struct psci_power_state state,
	124	unsigned long entry_point)
	125	{
	126	int err;
	127	u32 fn, power_state;
	128
	129	fn = psci_function_id[PSCI_FN_CPU_SUSPEND];
	130	power_state = psci_power_state_pack(state);
	131	err = invoke_psci_fn(fn, power_state, entry_point, 0);
	132	return psci_to_linux_errno(err);
	133	}
	134
	135	static int psci_cpu_off(struct psci_power_state state)
	136	{
	137	int err;
	138	u32 fn, power_state;
	139
	140	fn = psci_function_id[PSCI_FN_CPU_OFF];
	141	power_state = psci_power_state_pack(state);
	142	err = invoke_psci_fn(fn, power_state, 0, 0);
	143	return psci_to_linux_errno(err);
	144	}
	145
	146	static int psci_cpu_on(unsigned long cpuid, unsigned long entry_point)
	147	{
	148	int err;
	149	u32 fn;
	150
	151	fn = psci_function_id[PSCI_FN_CPU_ON];
	152	err = invoke_psci_fn(fn, cpuid, entry_point, 0);
	153	return psci_to_linux_errno(err);
	154	}
	155
	156	static int psci_migrate(unsigned long cpuid)
	157	{
	158	int err;
	159	u32 fn;
	160
	161	fn = psci_function_id[PSCI_FN_MIGRATE];
	162	err = invoke_psci_fn(fn, cpuid, 0, 0);
	163	return psci_to_linux_errno(err);
	164	}
	165
e71246a2 AC	166	static int psci_affinity_info(unsigned long target_affinity,
	167	unsigned long lowest_affinity_level)
	168	{
	169	int err;
	170	u32 fn;
e790f1de	171
e71246a2 AC	172	fn = psci_function_id[PSCI_FN_AFFINITY_INFO];
	173	err = invoke_psci_fn(fn, target_affinity, lowest_affinity_level, 0);
	174	return err;
	175	}
	176
	177	static int psci_migrate_info_type(void)
e790f1de	178	{
e71246a2 AC	179	int err;
e71246a2 AC	180	u32 fn;
e790f1de	181
e71246a2 AC	182	fn = psci_function_id[PSCI_FN_MIGRATE_INFO_TYPE];
	183	err = invoke_psci_fn(fn, 0, 0, 0);
	184	return err;
	185	}
e790f1de	186
18910ab0 LP	187	static int __maybe_unused cpu_psci_cpu_init_idle(struct device_node *cpu_node,
	188	unsigned int cpu)
	189	{
	190	int i, ret, count = 0;
	191	struct psci_power_state *psci_states;
	192	struct device_node *state_node;
	193
	194	/*
	195	* If the PSCI cpu_suspend function hook has not been initialized
	196	* idle states must not be enabled, so bail out
	197	*/
	198	if (!psci_ops.cpu_suspend)
	199	return -EOPNOTSUPP;
	200
	201	/* Count idle states */
	202	while ((state_node = of_parse_phandle(cpu_node, "cpu-idle-states",
	203	count))) {
	204	count++;
	205	of_node_put(state_node);
	206	}
	207
	208	if (!count)
	209	return -ENODEV;
	210
	211	psci_states = kcalloc(count, sizeof(*psci_states), GFP_KERNEL);
	212	if (!psci_states)
	213	return -ENOMEM;
	214
	215	for (i = 0; i < count; i++) {
	216	u32 psci_power_state;
	217
	218	state_node = of_parse_phandle(cpu_node, "cpu-idle-states", i);
	219
	220	ret = of_property_read_u32(state_node,
	221	"arm,psci-suspend-param",
	222	&psci_power_state);
	223	if (ret) {
	224	pr_warn(" * %s missing arm,psci-suspend-param property\n",
	225	state_node->full_name);
	226	of_node_put(state_node);
	227	goto free_mem;
	228	}
	229
	230	of_node_put(state_node);
	231	pr_debug("psci-power-state %#x index %d\n", psci_power_state,
	232	i);
	233	psci_power_state_unpack(psci_power_state, &psci_states[i]);
	234	}
	235	/* Idle states parsed correctly, initialize per-cpu pointer */
	236	per_cpu(psci_power_state, cpu) = psci_states;
	237	return 0;
	238
	239	free_mem:
	240	kfree(psci_states);
	241	return ret;
	242	}
	243
e71246a2 AC	244	static int get_set_conduit_method(struct device_node *np)
	245	{
	246	const char *method;
	247
	248	pr_info("probing for conduit method from DT.\n");
e790f1de WD	249
e790f1de WD	250	if (of_property_read_string(np, "method", &method)) {
e71246a2 AC	251	pr_warn("missing \"method\" property\n");
e71246a2 AC	252	return -ENXIO;
e790f1de WD	253	}
	254
	255	if (!strcmp("hvc", method)) {
	256	invoke_psci_fn = __invoke_psci_fn_hvc;
	257	} else if (!strcmp("smc", method)) {
	258	invoke_psci_fn = __invoke_psci_fn_smc;
	259	} else {
e71246a2 AC	260	pr_warn("invalid \"method\" property: %s\n", method);
	261	return -EINVAL;
	262	}
	263	return 0;
	264	}
	265
	266	static void psci_sys_reset(enum reboot_mode reboot_mode, const char *cmd)
	267	{
	268	invoke_psci_fn(PSCI_0_2_FN_SYSTEM_RESET, 0, 0, 0);
	269	}
	270
	271	static void psci_sys_poweroff(void)
	272	{
	273	invoke_psci_fn(PSCI_0_2_FN_SYSTEM_OFF, 0, 0, 0);
	274	}
	275
	276	/*
	277	* PSCI Function IDs for v0.2+ are well defined so use
	278	* standard values.
	279	*/
b9e97ef9	280	static int __init psci_0_2_init(struct device_node *np)
e71246a2 AC	281	{
	282	int err, ver;
	283
	284	err = get_set_conduit_method(np);
	285
	286	if (err)
e790f1de	287	goto out_put_node;
e71246a2 AC	288
	289	ver = psci_get_version();
	290
	291	if (ver == PSCI_RET_NOT_SUPPORTED) {
	292	/* PSCI v0.2 mandates implementation of PSCI_ID_VERSION. */
	293	pr_err("PSCI firmware does not comply with the v0.2 spec.\n");
	294	err = -EOPNOTSUPP;
	295	goto out_put_node;
	296	} else {
	297	pr_info("PSCIv%d.%d detected in firmware.\n",
	298	PSCI_VERSION_MAJOR(ver),
	299	PSCI_VERSION_MINOR(ver));
	300
	301	if (PSCI_VERSION_MAJOR(ver) == 0 &&
	302	PSCI_VERSION_MINOR(ver) < 2) {
	303	err = -EINVAL;
	304	pr_err("Conflicting PSCI version detected.\n");
	305	goto out_put_node;
	306	}
e790f1de WD	307	}
e790f1de WD	308
e71246a2 AC	309	pr_info("Using standard PSCI v0.2 function IDs\n");
	310	psci_function_id[PSCI_FN_CPU_SUSPEND] = PSCI_0_2_FN64_CPU_SUSPEND;
	311	psci_ops.cpu_suspend = psci_cpu_suspend;
	312
	313	psci_function_id[PSCI_FN_CPU_OFF] = PSCI_0_2_FN_CPU_OFF;
	314	psci_ops.cpu_off = psci_cpu_off;
	315
	316	psci_function_id[PSCI_FN_CPU_ON] = PSCI_0_2_FN64_CPU_ON;
	317	psci_ops.cpu_on = psci_cpu_on;
	318
	319	psci_function_id[PSCI_FN_MIGRATE] = PSCI_0_2_FN64_MIGRATE;
	320	psci_ops.migrate = psci_migrate;
	321
	322	psci_function_id[PSCI_FN_AFFINITY_INFO] = PSCI_0_2_FN64_AFFINITY_INFO;
	323	psci_ops.affinity_info = psci_affinity_info;
	324
	325	psci_function_id[PSCI_FN_MIGRATE_INFO_TYPE] =
	326	PSCI_0_2_FN_MIGRATE_INFO_TYPE;
	327	psci_ops.migrate_info_type = psci_migrate_info_type;
	328
	329	arm_pm_restart = psci_sys_reset;
	330
	331	pm_power_off = psci_sys_poweroff;
	332
	333	out_put_node:
	334	of_node_put(np);
	335	return err;
	336	}
	337
	338	/*
	339	* PSCI < v0.2 get PSCI Function IDs via DT.
	340	*/
b9e97ef9	341	static int __init psci_0_1_init(struct device_node *np)
e71246a2 AC	342	{
	343	u32 id;
	344	int err;
	345
	346	err = get_set_conduit_method(np);
	347
	348	if (err)
	349	goto out_put_node;
	350
	351	pr_info("Using PSCI v0.1 Function IDs from DT\n");
	352
e790f1de WD	353	if (!of_property_read_u32(np, "cpu_suspend", &id)) {
	354	psci_function_id[PSCI_FN_CPU_SUSPEND] = id;
	355	psci_ops.cpu_suspend = psci_cpu_suspend;
	356	}
	357
	358	if (!of_property_read_u32(np, "cpu_off", &id)) {
	359	psci_function_id[PSCI_FN_CPU_OFF] = id;
	360	psci_ops.cpu_off = psci_cpu_off;
	361	}
	362
	363	if (!of_property_read_u32(np, "cpu_on", &id)) {
	364	psci_function_id[PSCI_FN_CPU_ON] = id;
	365	psci_ops.cpu_on = psci_cpu_on;
	366	}
	367
	368	if (!of_property_read_u32(np, "migrate", &id)) {
	369	psci_function_id[PSCI_FN_MIGRATE] = id;
	370	psci_ops.migrate = psci_migrate;
	371	}
	372
	373	out_put_node:
	374	of_node_put(np);
e71246a2 AC	375	return err;
	376	}
	377
	378	static const struct of_device_id psci_of_match[] __initconst = {
	379	{ .compatible = "arm,psci", .data = psci_0_1_init},
	380	{ .compatible = "arm,psci-0.2", .data = psci_0_2_init},
	381	{},
	382	};
	383
	384	int __init psci_init(void)
	385	{
	386	struct device_node *np;
	387	const struct of_device_id *matched_np;
	388	psci_initcall_t init_fn;
	389
	390	np = of_find_matching_node_and_match(NULL, psci_of_match, &matched_np);
	391
	392	if (!np)
	393	return -ENODEV;
	394
	395	init_fn = (psci_initcall_t)matched_np->data;
	396	return init_fn(np);
e790f1de	397	}
00ef54bb MR	398
	399	#ifdef CONFIG_SMP
	400
cd1aebf5	401	static int __init cpu_psci_cpu_init(struct device_node *dn, unsigned int cpu)
00ef54bb MR	402	{
	403	return 0;
	404	}
	405
cd1aebf5	406	static int __init cpu_psci_cpu_prepare(unsigned int cpu)
00ef54bb	407	{
00ef54bb MR	408	if (!psci_ops.cpu_on) {
	409	pr_err("no cpu_on method, not booting CPU%d\n", cpu);
	410	return -ENODEV;
	411	}
	412
00ef54bb MR	413	return 0;
	414	}
	415
652af899 MR	416	static int cpu_psci_cpu_boot(unsigned int cpu)
	417	{
	418	int err = psci_ops.cpu_on(cpu_logical_map(cpu), __pa(secondary_entry));
	419	if (err)
288ac26c	420	pr_err("failed to boot CPU%d (%d)\n", cpu, err);
652af899 MR	421
	422	return err;
	423	}
	424
831ccf79 MR	425	#ifdef CONFIG_HOTPLUG_CPU
	426	static int cpu_psci_cpu_disable(unsigned int cpu)
	427	{
	428	/* Fail early if we don't have CPU_OFF support */
	429	if (!psci_ops.cpu_off)
	430	return -EOPNOTSUPP;
	431	return 0;
	432	}
	433
	434	static void cpu_psci_cpu_die(unsigned int cpu)
	435	{
	436	int ret;
	437	/*
	438	* There are no known implementations of PSCI actually using the
	439	* power state field, pass a sensible default for now.
	440	*/
	441	struct psci_power_state state = {
	442	.type = PSCI_POWER_STATE_TYPE_POWER_DOWN,
	443	};
	444
	445	ret = psci_ops.cpu_off(state);
	446
288ac26c	447	pr_crit("unable to power off CPU%u (%d)\n", cpu, ret);
831ccf79	448	}
c814ca02 AC	449
	450	static int cpu_psci_cpu_kill(unsigned int cpu)
	451	{
	452	int err, i;
	453
	454	if (!psci_ops.affinity_info)
	455	return 1;
	456	/*
	457	* cpu_kill could race with cpu_die and we can
	458	* potentially end up declaring this cpu undead
	459	* while it is dying. So, try again a few times.
	460	*/
	461
	462	for (i = 0; i < 10; i++) {
	463	err = psci_ops.affinity_info(cpu_logical_map(cpu), 0);
	464	if (err == PSCI_0_2_AFFINITY_LEVEL_OFF) {
	465	pr_info("CPU%d killed.\n", cpu);
	466	return 1;
	467	}
	468
	469	msleep(10);
	470	pr_info("Retrying again to check for CPU kill\n");
	471	}
	472
	473	pr_warn("CPU%d may not have shut down cleanly (AFFINITY_INFO reports %d)\n",
	474	cpu, err);
	475	/* Make op_cpu_kill() fail. */
	476	return 0;
	477	}
831ccf79	478	#endif
756854d9	479	#endif
831ccf79	480
18910ab0 LP	481	static int psci_suspend_finisher(unsigned long index)
18910ab0 LP	482	{
56e4dea8	483	struct psci_power_state *state = __this_cpu_read(psci_power_state);
18910ab0 LP	484
	485	return psci_ops.cpu_suspend(state[index - 1],
	486	virt_to_phys(cpu_resume));
	487	}
	488
	489	static int __maybe_unused cpu_psci_cpu_suspend(unsigned long index)
	490	{
	491	int ret;
56e4dea8	492	struct psci_power_state *state = __this_cpu_read(psci_power_state);
18910ab0 LP	493	/*
	494	* idle state index 0 corresponds to wfi, should never be called
	495	* from the cpu_suspend operations
	496	*/
	497	if (WARN_ON_ONCE(!index))
	498	return -EINVAL;
	499
f4fd36b8	500	if (state[index - 1].type == PSCI_POWER_STATE_TYPE_STANDBY)
18910ab0 LP	501	ret = psci_ops.cpu_suspend(state[index - 1], 0);
	502	else
	503	ret = __cpu_suspend(index, psci_suspend_finisher);
	504
	505	return ret;
	506	}
	507
cd1aebf5	508	const struct cpu_operations cpu_psci_ops = {
00ef54bb	509	.name = "psci",
18910ab0 LP	510	#ifdef CONFIG_CPU_IDLE
	511	.cpu_init_idle = cpu_psci_cpu_init_idle,
	512	.cpu_suspend = cpu_psci_cpu_suspend,
	513	#endif
756854d9	514	#ifdef CONFIG_SMP
cd1aebf5 MR	515	.cpu_init = cpu_psci_cpu_init,
cd1aebf5 MR	516	.cpu_prepare = cpu_psci_cpu_prepare,
652af899	517	.cpu_boot = cpu_psci_cpu_boot,
831ccf79 MR	518	#ifdef CONFIG_HOTPLUG_CPU
	519	.cpu_disable = cpu_psci_cpu_disable,
	520	.cpu_die = cpu_psci_cpu_die,
c814ca02	521	.cpu_kill = cpu_psci_cpu_kill,
831ccf79	522	#endif
756854d9	523	#endif
00ef54bb MR	524	};
00ef54bb MR	525