[linux-2.6-block.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 <asm/compiler.h>
#include <asm/cpu_ops.h>
#include <asm/errno.h>
#include <asm/psci.h>
#include <asm/smp_plat.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);
};

static struct psci_operations psci_ops;

static int (*invoke_psci_fn)(u64, u64, u64, u64);

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];

#define PSCI_RET_SUCCESS		0
#define PSCI_RET_EOPNOTSUPP		-1
#define PSCI_RET_EINVAL			-2
#define PSCI_RET_EPERM			-3

static int psci_to_linux_errno(int errno)
{
	switch (errno) {
	case PSCI_RET_SUCCESS:
		return 0;
	case PSCI_RET_EOPNOTSUPP:
		return -EOPNOTSUPP;
	case PSCI_RET_EINVAL:
		return -EINVAL;
	case PSCI_RET_EPERM:
		return -EPERM;
	};

	return -EINVAL;
}

#define PSCI_POWER_STATE_ID_MASK	0xffff
#define PSCI_POWER_STATE_ID_SHIFT	0
#define PSCI_POWER_STATE_TYPE_MASK	0x1
#define PSCI_POWER_STATE_TYPE_SHIFT	16
#define PSCI_POWER_STATE_AFFL_MASK	0x3
#define PSCI_POWER_STATE_AFFL_SHIFT	24

static u32 psci_power_state_pack(struct psci_power_state state)
{
	return	((state.id & PSCI_POWER_STATE_ID_MASK)
			<< PSCI_POWER_STATE_ID_SHIFT)	|
		((state.type & PSCI_POWER_STATE_TYPE_MASK)
			<< PSCI_POWER_STATE_TYPE_SHIFT)	|
		((state.affinity_level & PSCI_POWER_STATE_AFFL_MASK)
			<< PSCI_POWER_STATE_AFFL_SHIFT);
}

/*
 * The following two functions are invoked via the invoke_psci_fn pointer
 * and will not be inlined, allowing us to piggyback on the AAPCS.
 */
static noinline int __invoke_psci_fn_hvc(u64 function_id, u64 arg0, u64 arg1,
					 u64 arg2)
{
	asm volatile(
			__asmeq("%0", "x0")
			__asmeq("%1", "x1")
			__asmeq("%2", "x2")
			__asmeq("%3", "x3")
			"hvc	#0\n"
		: "+r" (function_id)
		: "r" (arg0), "r" (arg1), "r" (arg2));

	return function_id;
}

static noinline int __invoke_psci_fn_smc(u64 function_id, u64 arg0, u64 arg1,
					 u64 arg2)
{
	asm volatile(
			__asmeq("%0", "x0")
			__asmeq("%1", "x1")
			__asmeq("%2", "x2")
			__asmeq("%3", "x3")
			"smc	#0\n"
		: "+r" (function_id)
		: "r" (arg0), "r" (arg1), "r" (arg2));

	return function_id;
}

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 const struct of_device_id psci_of_match[] __initconst = {
	{ .compatible = "arm,psci",	},
	{},
};

int __init psci_init(void)
{
	struct device_node *np;
	const char *method;
	u32 id;
	int err = 0;

	np = of_find_matching_node(NULL, psci_of_match);
	if (!np)
		return -ENODEV;

	pr_info("probing function IDs from device-tree\n");

	if (of_property_read_string(np, "method", &method)) {
		pr_warning("missing \"method\" property\n");
		err = -ENXIO;
		goto out_put_node;
	}

	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_warning("invalid \"method\" property: %s\n", method);
		err = -EINVAL;
		goto out_put_node;
	}

	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;
}

#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("psci: 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("psci: unable to power off CPU%u (%d)\n", cpu, ret);
}
#endif

const struct cpu_operations cpu_psci_ops = {
	.name		= "psci",
	.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,
#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>
e790f1de WD	21
e790f1de WD	22	#include <asm/compiler.h>
cd1aebf5	23	#include <asm/cpu_ops.h>
e790f1de WD	24	#include <asm/errno.h>
e790f1de WD	25	#include <asm/psci.h>
00ef54bb	26	#include <asm/smp_plat.h>
e790f1de	27
00ef54bb MR	28	#define PSCI_POWER_STATE_TYPE_STANDBY 0
	29	#define PSCI_POWER_STATE_TYPE_POWER_DOWN 1
	30
	31	struct psci_power_state {
	32	u16 id;
	33	u8 type;
	34	u8 affinity_level;
	35	};
	36
	37	struct psci_operations {
	38	int (*cpu_suspend)(struct psci_power_state state,
	39	unsigned long entry_point);
	40	int (*cpu_off)(struct psci_power_state state);
	41	int (*cpu_on)(unsigned long cpuid, unsigned long entry_point);
	42	int (*migrate)(unsigned long cpuid);
	43	};
	44
	45	static struct psci_operations psci_ops;
e790f1de WD	46
	47	static int (*invoke_psci_fn)(u64, u64, u64, u64);
	48
	49	enum psci_function {
	50	PSCI_FN_CPU_SUSPEND,
	51	PSCI_FN_CPU_ON,
	52	PSCI_FN_CPU_OFF,
	53	PSCI_FN_MIGRATE,
	54	PSCI_FN_MAX,
	55	};
	56
	57	static u32 psci_function_id[PSCI_FN_MAX];
	58
	59	#define PSCI_RET_SUCCESS 0
	60	#define PSCI_RET_EOPNOTSUPP -1
	61	#define PSCI_RET_EINVAL -2
	62	#define PSCI_RET_EPERM -3
	63
	64	static int psci_to_linux_errno(int errno)
	65	{
	66	switch (errno) {
	67	case PSCI_RET_SUCCESS:
	68	return 0;
	69	case PSCI_RET_EOPNOTSUPP:
	70	return -EOPNOTSUPP;
	71	case PSCI_RET_EINVAL:
	72	return -EINVAL;
	73	case PSCI_RET_EPERM:
	74	return -EPERM;
	75	};
	76
	77	return -EINVAL;
	78	}
	79
	80	#define PSCI_POWER_STATE_ID_MASK 0xffff
	81	#define PSCI_POWER_STATE_ID_SHIFT 0
	82	#define PSCI_POWER_STATE_TYPE_MASK 0x1
	83	#define PSCI_POWER_STATE_TYPE_SHIFT 16
	84	#define PSCI_POWER_STATE_AFFL_MASK 0x3
	85	#define PSCI_POWER_STATE_AFFL_SHIFT 24
	86
	87	static u32 psci_power_state_pack(struct psci_power_state state)
	88	{
	89	return ((state.id & PSCI_POWER_STATE_ID_MASK)
	90	<< PSCI_POWER_STATE_ID_SHIFT) \|
	91	((state.type & PSCI_POWER_STATE_TYPE_MASK)
	92	<< PSCI_POWER_STATE_TYPE_SHIFT) \|
	93	((state.affinity_level & PSCI_POWER_STATE_AFFL_MASK)
	94	<< PSCI_POWER_STATE_AFFL_SHIFT);
	95	}
	96
	97	/*
	98	* The following two functions are invoked via the invoke_psci_fn pointer
	99	* and will not be inlined, allowing us to piggyback on the AAPCS.
	100	*/
	101	static noinline int __invoke_psci_fn_hvc(u64 function_id, u64 arg0, u64 arg1,
	102	u64 arg2)
	103	{
	104	asm volatile(
	105	__asmeq("%0", "x0")
	106	__asmeq("%1", "x1")
	107	__asmeq("%2", "x2")
	108	__asmeq("%3", "x3")
	109	"hvc #0\n"
110	: "+r" (function_id)
111	: "r" (arg0), "r" (arg1), "r" (arg2));
112
113	return function_id;
114	}
115
116	static noinline int __invoke_psci_fn_smc(u64 function_id, u64 arg0, u64 arg1,
117	u64 arg2)
118	{
119	asm volatile(
120	__asmeq("%0", "x0")
121	__asmeq("%1", "x1")
122	__asmeq("%2", "x2")
123	__asmeq("%3", "x3")
124	"smc #0\n"
125	: "+r" (function_id)
126	: "r" (arg0), "r" (arg1), "r" (arg2));
127
128	return function_id;
129	}
130
131	static int psci_cpu_suspend(struct psci_power_state state,
132	unsigned long entry_point)
133	{
134	int err;
135	u32 fn, power_state;
136
137	fn = psci_function_id[PSCI_FN_CPU_SUSPEND];
138	power_state = psci_power_state_pack(state);
139	err = invoke_psci_fn(fn, power_state, entry_point, 0);
140	return psci_to_linux_errno(err);
141	}
142
143	static int psci_cpu_off(struct psci_power_state state)
144	{
145	int err;
146	u32 fn, power_state;
147
148	fn = psci_function_id[PSCI_FN_CPU_OFF];
149	power_state = psci_power_state_pack(state);
150	err = invoke_psci_fn(fn, power_state, 0, 0);
151	return psci_to_linux_errno(err);
152	}
153
154	static int psci_cpu_on(unsigned long cpuid, unsigned long entry_point)
155	{
156	int err;
157	u32 fn;
158
159	fn = psci_function_id[PSCI_FN_CPU_ON];
160	err = invoke_psci_fn(fn, cpuid, entry_point, 0);
161	return psci_to_linux_errno(err);
162	}
163
164	static int psci_migrate(unsigned long cpuid)
165	{
166	int err;
167	u32 fn;
168
169	fn = psci_function_id[PSCI_FN_MIGRATE];
170	err = invoke_psci_fn(fn, cpuid, 0, 0);
171	return psci_to_linux_errno(err);
172	}
173
174	static const struct of_device_id psci_of_match[] __initconst = {
175	{ .compatible = "arm,psci", },
176	{},
177	};
178
179	int __init psci_init(void)
180	{
181	struct device_node *np;
182	const char *method;
183	u32 id;
184	int err = 0;
185
186	np = of_find_matching_node(NULL, psci_of_match);
187	if (!np)
188	return -ENODEV;
189
190	pr_info("probing function IDs from device-tree\n");
191
192	if (of_property_read_string(np, "method", &method)) {
193	pr_warning("missing \"method\" property\n");
194	err = -ENXIO;
195	goto out_put_node;
196	}
197
198	if (!strcmp("hvc", method)) {
199	invoke_psci_fn = __invoke_psci_fn_hvc;
200	} else if (!strcmp("smc", method)) {
201	invoke_psci_fn = __invoke_psci_fn_smc;
202	} else {
203	pr_warning("invalid \"method\" property: %s\n", method);
204	err = -EINVAL;
205	goto out_put_node;
206	}
207
208	if (!of_property_read_u32(np, "cpu_suspend", &id)) {
209	psci_function_id[PSCI_FN_CPU_SUSPEND] = id;
210	psci_ops.cpu_suspend = psci_cpu_suspend;
211	}
212
213	if (!of_property_read_u32(np, "cpu_off", &id)) {
214	psci_function_id[PSCI_FN_CPU_OFF] = id;
215	psci_ops.cpu_off = psci_cpu_off;
216	}
217
218	if (!of_property_read_u32(np, "cpu_on", &id)) {
219	psci_function_id[PSCI_FN_CPU_ON] = id;
220	psci_ops.cpu_on = psci_cpu_on;
221	}
222
223	if (!of_property_read_u32(np, "migrate", &id)) {
224	psci_function_id[PSCI_FN_MIGRATE] = id;
225	psci_ops.migrate = psci_migrate;
226	}
227
228	out_put_node:
229	of_node_put(np);
230	return err;
231	}
00ef54bb MR	232
	233	#ifdef CONFIG_SMP
	234
cd1aebf5	235	static int __init cpu_psci_cpu_init(struct device_node *dn, unsigned int cpu)
00ef54bb MR	236	{
	237	return 0;
	238	}
	239
cd1aebf5	240	static int __init cpu_psci_cpu_prepare(unsigned int cpu)
00ef54bb	241	{
00ef54bb MR	242	if (!psci_ops.cpu_on) {
	243	pr_err("no cpu_on method, not booting CPU%d\n", cpu);
	244	return -ENODEV;
	245	}
	246
00ef54bb MR	247	return 0;
	248	}
	249
652af899 MR	250	static int cpu_psci_cpu_boot(unsigned int cpu)
	251	{
	252	int err = psci_ops.cpu_on(cpu_logical_map(cpu), __pa(secondary_entry));
	253	if (err)
	254	pr_err("psci: failed to boot CPU%d (%d)\n", cpu, err);
	255
	256	return err;
	257	}
	258
831ccf79 MR	259	#ifdef CONFIG_HOTPLUG_CPU
	260	static int cpu_psci_cpu_disable(unsigned int cpu)
	261	{
	262	/* Fail early if we don't have CPU_OFF support */
	263	if (!psci_ops.cpu_off)
	264	return -EOPNOTSUPP;
	265	return 0;
	266	}
	267
	268	static void cpu_psci_cpu_die(unsigned int cpu)
	269	{
	270	int ret;
	271	/*
	272	* There are no known implementations of PSCI actually using the
	273	* power state field, pass a sensible default for now.
	274	*/
	275	struct psci_power_state state = {
	276	.type = PSCI_POWER_STATE_TYPE_POWER_DOWN,
	277	};
	278
	279	ret = psci_ops.cpu_off(state);
	280
	281	pr_crit("psci: unable to power off CPU%u (%d)\n", cpu, ret);
	282	}
	283	#endif
	284
cd1aebf5	285	const struct cpu_operations cpu_psci_ops = {
00ef54bb	286	.name = "psci",
cd1aebf5 MR	287	.cpu_init = cpu_psci_cpu_init,
cd1aebf5 MR	288	.cpu_prepare = cpu_psci_cpu_prepare,
652af899	289	.cpu_boot = cpu_psci_cpu_boot,
831ccf79 MR	290	#ifdef CONFIG_HOTPLUG_CPU
	291	.cpu_disable = cpu_psci_cpu_disable,
	292	.cpu_die = cpu_psci_cpu_die,
	293	#endif
00ef54bb MR	294	};
	295
	296	#endif