[linux-2.6-block.git] / drivers / cpufreq / ia64-acpi-cpufreq.c

/*
 * This file provides the ACPI based P-state support. This
 * module works with generic cpufreq infrastructure. Most of
 * the code is based on i386 version
 * (arch/i386/kernel/cpu/cpufreq/acpi-cpufreq.c)
 *
 * Copyright (C) 2005 Intel Corp
 *      Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
 */

#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/cpufreq.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <asm/io.h>
#include <asm/uaccess.h>
#include <asm/pal.h>

#include <linux/acpi.h>
#include <acpi/processor.h>

MODULE_AUTHOR("Venkatesh Pallipadi");
MODULE_DESCRIPTION("ACPI Processor P-States Driver");
MODULE_LICENSE("GPL");


struct cpufreq_acpi_io {
	struct acpi_processor_performance	acpi_data;
	unsigned int				resume;
};

static struct cpufreq_acpi_io	*acpi_io_data[NR_CPUS];

static struct cpufreq_driver acpi_cpufreq_driver;


static int
processor_set_pstate (
	u32	value)
{
	s64 retval;

	pr_debug("processor_set_pstate\n");

	retval = ia64_pal_set_pstate((u64)value);

	if (retval) {
		pr_debug("Failed to set freq to 0x%x, with error 0x%lx\n",
		        value, retval);
		return -ENODEV;
	}
	return (int)retval;
}


static int
processor_get_pstate (
	u32	*value)
{
	u64	pstate_index = 0;
	s64 	retval;

	pr_debug("processor_get_pstate\n");

	retval = ia64_pal_get_pstate(&pstate_index,
	                             PAL_GET_PSTATE_TYPE_INSTANT);
	*value = (u32) pstate_index;

	if (retval)
		pr_debug("Failed to get current freq with "
			"error 0x%lx, idx 0x%x\n", retval, *value);

	return (int)retval;
}


/* To be used only after data->acpi_data is initialized */
static unsigned
extract_clock (
	struct cpufreq_acpi_io *data,
	unsigned value,
	unsigned int cpu)
{
	unsigned long i;

	pr_debug("extract_clock\n");

	for (i = 0; i < data->acpi_data.state_count; i++) {
		if (value == data->acpi_data.states[i].status)
			return data->acpi_data.states[i].core_frequency;
	}
	return data->acpi_data.states[i-1].core_frequency;
}


static unsigned int
processor_get_freq (
	struct cpufreq_acpi_io	*data,
	unsigned int		cpu)
{
	int			ret = 0;
	u32			value = 0;
	cpumask_t		saved_mask;
	unsigned long 		clock_freq;

	pr_debug("processor_get_freq\n");

	saved_mask = current->cpus_allowed;
	set_cpus_allowed_ptr(current, cpumask_of(cpu));
	if (smp_processor_id() != cpu)
		goto migrate_end;

	/* processor_get_pstate gets the instantaneous frequency */
	ret = processor_get_pstate(&value);

	if (ret) {
		set_cpus_allowed_ptr(current, &saved_mask);
		printk(KERN_WARNING "get performance failed with error %d\n",
		       ret);
		ret = 0;
		goto migrate_end;
	}
	clock_freq = extract_clock(data, value, cpu);
	ret = (clock_freq*1000);

migrate_end:
	set_cpus_allowed_ptr(current, &saved_mask);
	return ret;
}


static int
processor_set_freq (
	struct cpufreq_acpi_io	*data,
	struct cpufreq_policy   *policy,
	int			state)
{
	int			ret = 0;
	u32			value = 0;
	cpumask_t		saved_mask;
	int			retval;

	pr_debug("processor_set_freq\n");

	saved_mask = current->cpus_allowed;
	set_cpus_allowed_ptr(current, cpumask_of(policy->cpu));
	if (smp_processor_id() != policy->cpu) {
		retval = -EAGAIN;
		goto migrate_end;
	}

	if (state == data->acpi_data.state) {
		if (unlikely(data->resume)) {
			pr_debug("Called after resume, resetting to P%d\n", state);
			data->resume = 0;
		} else {
			pr_debug("Already at target state (P%d)\n", state);
			retval = 0;
			goto migrate_end;
		}
	}

	pr_debug("Transitioning from P%d to P%d\n",
		data->acpi_data.state, state);

	/*
	 * First we write the target state's 'control' value to the
	 * control_register.
	 */

	value = (u32) data->acpi_data.states[state].control;

	pr_debug("Transitioning to state: 0x%08x\n", value);

	ret = processor_set_pstate(value);
	if (ret) {
		printk(KERN_WARNING "Transition failed with error %d\n", ret);
		retval = -ENODEV;
		goto migrate_end;
	}

	data->acpi_data.state = state;

	retval = 0;

migrate_end:
	set_cpus_allowed_ptr(current, &saved_mask);
	return (retval);
}


static unsigned int
acpi_cpufreq_get (
	unsigned int		cpu)
{
	struct cpufreq_acpi_io *data = acpi_io_data[cpu];

	pr_debug("acpi_cpufreq_get\n");

	return processor_get_freq(data, cpu);
}


static int
acpi_cpufreq_target (
	struct cpufreq_policy   *policy,
	unsigned int index)
{
	return processor_set_freq(acpi_io_data[policy->cpu], policy, index);
}

static int
acpi_cpufreq_cpu_init (
	struct cpufreq_policy   *policy)
{
	unsigned int		i;
	unsigned int		cpu = policy->cpu;
	struct cpufreq_acpi_io	*data;
	unsigned int		result = 0;
	struct cpufreq_frequency_table *freq_table;

	pr_debug("acpi_cpufreq_cpu_init\n");

	data = kzalloc(sizeof(*data), GFP_KERNEL);
	if (!data)
		return (-ENOMEM);

	acpi_io_data[cpu] = data;

	result = acpi_processor_register_performance(&data->acpi_data, cpu);

	if (result)
		goto err_free;

	/* capability check */
	if (data->acpi_data.state_count <= 1) {
		pr_debug("No P-States\n");
		result = -ENODEV;
		goto err_unreg;
	}

	if ((data->acpi_data.control_register.space_id !=
					ACPI_ADR_SPACE_FIXED_HARDWARE) ||
	    (data->acpi_data.status_register.space_id !=
					ACPI_ADR_SPACE_FIXED_HARDWARE)) {
		pr_debug("Unsupported address space [%d, %d]\n",
			(u32) (data->acpi_data.control_register.space_id),
			(u32) (data->acpi_data.status_register.space_id));
		result = -ENODEV;
		goto err_unreg;
	}

	/* alloc freq_table */
	freq_table = kzalloc(sizeof(*freq_table) *
	                           (data->acpi_data.state_count + 1),
	                           GFP_KERNEL);
	if (!freq_table) {
		result = -ENOMEM;
		goto err_unreg;
	}

	/* detect transition latency */
	policy->cpuinfo.transition_latency = 0;
	for (i=0; i<data->acpi_data.state_count; i++) {
		if ((data->acpi_data.states[i].transition_latency * 1000) >
		    policy->cpuinfo.transition_latency) {
			policy->cpuinfo.transition_latency =
			    data->acpi_data.states[i].transition_latency * 1000;
		}
	}

	/* table init */
	for (i = 0; i <= data->acpi_data.state_count; i++)
	{
		if (i < data->acpi_data.state_count) {
			freq_table[i].frequency =
			      data->acpi_data.states[i].core_frequency * 1000;
		} else {
			freq_table[i].frequency = CPUFREQ_TABLE_END;
		}
	}

	result = cpufreq_table_validate_and_show(policy, freq_table);
	if (result) {
		goto err_freqfree;
	}

	/* notify BIOS that we exist */
	acpi_processor_notify_smm(THIS_MODULE);

	printk(KERN_INFO "acpi-cpufreq: CPU%u - ACPI performance management "
	       "activated.\n", cpu);

	for (i = 0; i < data->acpi_data.state_count; i++)
		pr_debug("     %cP%d: %d MHz, %d mW, %d uS, %d uS, 0x%x 0x%x\n",
			(i == data->acpi_data.state?'*':' '), i,
			(u32) data->acpi_data.states[i].core_frequency,
			(u32) data->acpi_data.states[i].power,
			(u32) data->acpi_data.states[i].transition_latency,
			(u32) data->acpi_data.states[i].bus_master_latency,
			(u32) data->acpi_data.states[i].status,
			(u32) data->acpi_data.states[i].control);

	/* the first call to ->target() should result in us actually
	 * writing something to the appropriate registers. */
	data->resume = 1;

	return (result);

 err_freqfree:
	kfree(freq_table);
 err_unreg:
	acpi_processor_unregister_performance(cpu);
 err_free:
	kfree(data);
	acpi_io_data[cpu] = NULL;

	return (result);
}


static int
acpi_cpufreq_cpu_exit (
	struct cpufreq_policy   *policy)
{
	struct cpufreq_acpi_io *data = acpi_io_data[policy->cpu];

	pr_debug("acpi_cpufreq_cpu_exit\n");

	if (data) {
		acpi_io_data[policy->cpu] = NULL;
		acpi_processor_unregister_performance(policy->cpu);
		kfree(policy->freq_table);
		kfree(data);
	}

	return (0);
}


static struct cpufreq_driver acpi_cpufreq_driver = {
	.verify 	= cpufreq_generic_frequency_table_verify,
	.target_index	= acpi_cpufreq_target,
	.get 		= acpi_cpufreq_get,
	.init		= acpi_cpufreq_cpu_init,
	.exit		= acpi_cpufreq_cpu_exit,
	.name		= "acpi-cpufreq",
	.attr		= cpufreq_generic_attr,
};


static int __init
acpi_cpufreq_init (void)
{
	pr_debug("acpi_cpufreq_init\n");

 	return cpufreq_register_driver(&acpi_cpufreq_driver);
}


static void __exit
acpi_cpufreq_exit (void)
{
	pr_debug("acpi_cpufreq_exit\n");

	cpufreq_unregister_driver(&acpi_cpufreq_driver);
	return;
}


late_initcall(acpi_cpufreq_init);
module_exit(acpi_cpufreq_exit);
Commit	Line	Data
4db8699b	1	/*
4db8699b VP	2	* This file provides the ACPI based P-state support. This
	3	* module works with generic cpufreq infrastructure. Most of
	4	* the code is based on i386 version
	5	* (arch/i386/kernel/cpu/cpufreq/acpi-cpufreq.c)
	6	*
	7	* Copyright (C) 2005 Intel Corp
	8	* Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
	9	*/
	10
4db8699b	11	#include <linux/kernel.h>
5a0e3ad6	12	#include <linux/slab.h>
4db8699b VP	13	#include <linux/module.h>
	14	#include <linux/init.h>
	15	#include <linux/cpufreq.h>
	16	#include <linux/proc_fs.h>
	17	#include <linux/seq_file.h>
	18	#include <asm/io.h>
	19	#include <asm/uaccess.h>
	20	#include <asm/pal.h>
	21
	22	#include <linux/acpi.h>
	23	#include <acpi/processor.h>
	24
4db8699b VP	25	MODULE_AUTHOR("Venkatesh Pallipadi");
	26	MODULE_DESCRIPTION("ACPI Processor P-States Driver");
	27	MODULE_LICENSE("GPL");
	28
	29
	30	struct cpufreq_acpi_io {
	31	struct acpi_processor_performance acpi_data;
4db8699b VP	32	unsigned int resume;
	33	};
	34
	35	static struct cpufreq_acpi_io *acpi_io_data[NR_CPUS];
	36
	37	static struct cpufreq_driver acpi_cpufreq_driver;
	38
	39
	40	static int
	41	processor_set_pstate (
	42	u32 value)
	43	{
	44	s64 retval;
	45
2d06d8c4	46	pr_debug("processor_set_pstate\n");
4db8699b VP	47
	48	retval = ia64_pal_set_pstate((u64)value);
	49
	50	if (retval) {
2d06d8c4	51	pr_debug("Failed to set freq to 0x%x, with error 0x%lx\n",
4db8699b VP	52	value, retval);
	53	return -ENODEV;
	54	}
	55	return (int)retval;
	56	}
	57
	58
	59	static int
	60	processor_get_pstate (
	61	u32 *value)
	62	{
	63	u64 pstate_index = 0;
	64	s64 retval;
	65
2d06d8c4	66	pr_debug("processor_get_pstate\n");
4db8699b	67
17e77b1c VP	68	retval = ia64_pal_get_pstate(&pstate_index,
17e77b1c VP	69	PAL_GET_PSTATE_TYPE_INSTANT);
4db8699b VP	70	*value = (u32) pstate_index;
	71
	72	if (retval)
2d06d8c4	73	pr_debug("Failed to get current freq with "
60192db8	74	"error 0x%lx, idx 0x%x\n", retval, *value);
4db8699b VP	75
	76	return (int)retval;
	77	}
	78
	79
	80	/* To be used only after data->acpi_data is initialized */
	81	static unsigned
	82	extract_clock (
	83	struct cpufreq_acpi_io *data,
	84	unsigned value,
	85	unsigned int cpu)
	86	{
	87	unsigned long i;
	88
2d06d8c4	89	pr_debug("extract_clock\n");
4db8699b VP	90
4db8699b VP	91	for (i = 0; i < data->acpi_data.state_count; i++) {
17e77b1c	92	if (value == data->acpi_data.states[i].status)
4db8699b VP	93	return data->acpi_data.states[i].core_frequency;
	94	}
	95	return data->acpi_data.states[i-1].core_frequency;
	96	}
	97
	98
	99	static unsigned int
	100	processor_get_freq (
	101	struct cpufreq_acpi_io *data,
	102	unsigned int cpu)
	103	{
	104	int ret = 0;
	105	u32 value = 0;
	106	cpumask_t saved_mask;
	107	unsigned long clock_freq;
	108
2d06d8c4	109	pr_debug("processor_get_freq\n");
4db8699b VP	110
4db8699b VP	111	saved_mask = current->cpus_allowed;
552dce3a	112	set_cpus_allowed_ptr(current, cpumask_of(cpu));
182fdd22	113	if (smp_processor_id() != cpu)
4db8699b	114	goto migrate_end;
4db8699b	115
17e77b1c	116	/* processor_get_pstate gets the instantaneous frequency */
4db8699b VP	117	ret = processor_get_pstate(&value);
	118
	119	if (ret) {
552dce3a	120	set_cpus_allowed_ptr(current, &saved_mask);
4db8699b VP	121	printk(KERN_WARNING "get performance failed with error %d\n",
4db8699b VP	122	ret);
182fdd22	123	ret = 0;
4db8699b VP	124	goto migrate_end;
	125	}
	126	clock_freq = extract_clock(data, value, cpu);
	127	ret = (clock_freq*1000);
	128
	129	migrate_end:
552dce3a	130	set_cpus_allowed_ptr(current, &saved_mask);
4db8699b VP	131	return ret;
	132	}
	133
	134
	135	static int
	136	processor_set_freq (
	137	struct cpufreq_acpi_io *data,
b43a7ffb	138	struct cpufreq_policy *policy,
4db8699b VP	139	int state)
	140	{
	141	int ret = 0;
	142	u32 value = 0;
4db8699b VP	143	cpumask_t saved_mask;
	144	int retval;
	145
2d06d8c4	146	pr_debug("processor_set_freq\n");
4db8699b VP	147
4db8699b VP	148	saved_mask = current->cpus_allowed;
b43a7ffb VK	149	set_cpus_allowed_ptr(current, cpumask_of(policy->cpu));
b43a7ffb VK	150	if (smp_processor_id() != policy->cpu) {
4db8699b VP	151	retval = -EAGAIN;
	152	goto migrate_end;
	153	}
	154
	155	if (state == data->acpi_data.state) {
	156	if (unlikely(data->resume)) {
2d06d8c4	157	pr_debug("Called after resume, resetting to P%d\n", state);
4db8699b VP	158	data->resume = 0;
4db8699b VP	159	} else {
2d06d8c4	160	pr_debug("Already at target state (P%d)\n", state);
4db8699b VP	161	retval = 0;
	162	goto migrate_end;
	163	}
	164	}
	165
2d06d8c4	166	pr_debug("Transitioning from P%d to P%d\n",
4db8699b VP	167	data->acpi_data.state, state);
4db8699b VP	168
4db8699b VP	169	/*
	170	* First we write the target state's 'control' value to the
	171	* control_register.
	172	*/
	173
	174	value = (u32) data->acpi_data.states[state].control;
	175
2d06d8c4	176	pr_debug("Transitioning to state: 0x%08x\n", value);
4db8699b VP	177
	178	ret = processor_set_pstate(value);
	179	if (ret) {
4db8699b VP	180	printk(KERN_WARNING "Transition failed with error %d\n", ret);
	181	retval = -ENODEV;
	182	goto migrate_end;
	183	}
	184
4db8699b VP	185	data->acpi_data.state = state;
	186
	187	retval = 0;
	188
	189	migrate_end:
552dce3a	190	set_cpus_allowed_ptr(current, &saved_mask);
4db8699b VP	191	return (retval);
	192	}
	193
	194
	195	static unsigned int
	196	acpi_cpufreq_get (
	197	unsigned int cpu)
	198	{
	199	struct cpufreq_acpi_io *data = acpi_io_data[cpu];
	200
2d06d8c4	201	pr_debug("acpi_cpufreq_get\n");
4db8699b VP	202
	203	return processor_get_freq(data, cpu);
	204	}
	205
	206
	207	static int
	208	acpi_cpufreq_target (
	209	struct cpufreq_policy *policy,
9c0ebcf7	210	unsigned int index)
4db8699b	211	{
9c0ebcf7	212	return processor_set_freq(acpi_io_data[policy->cpu], policy, index);
4db8699b VP	213	}
4db8699b VP	214
4db8699b VP	215	static int
	216	acpi_cpufreq_cpu_init (
	217	struct cpufreq_policy *policy)
	218	{
	219	unsigned int i;
	220	unsigned int cpu = policy->cpu;
	221	struct cpufreq_acpi_io *data;
	222	unsigned int result = 0;
946c14f8	223	struct cpufreq_frequency_table *freq_table;
4db8699b	224
2d06d8c4	225	pr_debug("acpi_cpufreq_cpu_init\n");
4db8699b	226
d5b73cd8	227	data = kzalloc(sizeof(*data), GFP_KERNEL);
4db8699b VP	228	if (!data)
	229	return (-ENOMEM);
	230
4db8699b VP	231	acpi_io_data[cpu] = data;
4db8699b VP	232
4db8699b	233	result = acpi_processor_register_performance(&data->acpi_data, cpu);
4db8699b VP	234
	235	if (result)
	236	goto err_free;
	237
	238	/* capability check */
	239	if (data->acpi_data.state_count <= 1) {
2d06d8c4	240	pr_debug("No P-States\n");
4db8699b VP	241	result = -ENODEV;
	242	goto err_unreg;
	243	}
	244
	245	if ((data->acpi_data.control_register.space_id !=
	246	ACPI_ADR_SPACE_FIXED_HARDWARE) \|\|
	247	(data->acpi_data.status_register.space_id !=
	248	ACPI_ADR_SPACE_FIXED_HARDWARE)) {
2d06d8c4	249	pr_debug("Unsupported address space [%d, %d]\n",
4db8699b VP	250	(u32) (data->acpi_data.control_register.space_id),
	251	(u32) (data->acpi_data.status_register.space_id));
	252	result = -ENODEV;
	253	goto err_unreg;
	254	}
	255
	256	/* alloc freq_table */
946c14f8	257	freq_table = kzalloc(sizeof(freq_table)
4db8699b VP	258	(data->acpi_data.state_count + 1),
4db8699b VP	259	GFP_KERNEL);
946c14f8	260	if (!freq_table) {
4db8699b VP	261	result = -ENOMEM;
	262	goto err_unreg;
	263	}
	264
	265	/* detect transition latency */
	266	policy->cpuinfo.transition_latency = 0;
	267	for (i=0; i<data->acpi_data.state_count; i++) {
	268	if ((data->acpi_data.states[i].transition_latency * 1000) >
	269	policy->cpuinfo.transition_latency) {
	270	policy->cpuinfo.transition_latency =
	271	data->acpi_data.states[i].transition_latency * 1000;
	272	}
	273	}
4db8699b VP	274
	275	/* table init */
	276	for (i = 0; i <= data->acpi_data.state_count; i++)
	277	{
4db8699b	278	if (i < data->acpi_data.state_count) {
946c14f8	279	freq_table[i].frequency =
4db8699b VP	280	data->acpi_data.states[i].core_frequency * 1000;
4db8699b VP	281	} else {
946c14f8	282	freq_table[i].frequency = CPUFREQ_TABLE_END;
4db8699b VP	283	}
	284	}
	285
946c14f8	286	result = cpufreq_table_validate_and_show(policy, freq_table);
4db8699b VP	287	if (result) {
	288	goto err_freqfree;
	289	}
	290
	291	/* notify BIOS that we exist */
	292	acpi_processor_notify_smm(THIS_MODULE);
	293
	294	printk(KERN_INFO "acpi-cpufreq: CPU%u - ACPI performance management "
	295	"activated.\n", cpu);
	296
	297	for (i = 0; i < data->acpi_data.state_count; i++)
2d06d8c4	298	pr_debug(" %cP%d: %d MHz, %d mW, %d uS, %d uS, 0x%x 0x%x\n",
4db8699b VP	299	(i == data->acpi_data.state?'*':' '), i,
	300	(u32) data->acpi_data.states[i].core_frequency,
	301	(u32) data->acpi_data.states[i].power,
	302	(u32) data->acpi_data.states[i].transition_latency,
	303	(u32) data->acpi_data.states[i].bus_master_latency,
	304	(u32) data->acpi_data.states[i].status,
	305	(u32) data->acpi_data.states[i].control);
	306
4db8699b VP	307	/* the first call to ->target() should result in us actually
	308	* writing something to the appropriate registers. */
	309	data->resume = 1;
	310
	311	return (result);
	312
	313	err_freqfree:
946c14f8	314	kfree(freq_table);
4db8699b	315	err_unreg:
b2f8dc4c	316	acpi_processor_unregister_performance(cpu);
4db8699b VP	317	err_free:
	318	kfree(data);
	319	acpi_io_data[cpu] = NULL;
	320
	321	return (result);
	322	}
	323
	324
	325	static int
	326	acpi_cpufreq_cpu_exit (
	327	struct cpufreq_policy *policy)
	328	{
	329	struct cpufreq_acpi_io *data = acpi_io_data[policy->cpu];
	330
2d06d8c4	331	pr_debug("acpi_cpufreq_cpu_exit\n");
4db8699b VP	332
4db8699b VP	333	if (data) {
4db8699b	334	acpi_io_data[policy->cpu] = NULL;
b2f8dc4c	335	acpi_processor_unregister_performance(policy->cpu);
555f3fe9	336	kfree(policy->freq_table);
4db8699b VP	337	kfree(data);
	338	}
	339
	340	return (0);
	341	}
	342
	343
4db8699b	344	static struct cpufreq_driver acpi_cpufreq_driver = {
59b2413b	345	.verify = cpufreq_generic_frequency_table_verify,
9c0ebcf7	346	.target_index = acpi_cpufreq_target,
4db8699b VP	347	.get = acpi_cpufreq_get,
	348	.init = acpi_cpufreq_cpu_init,
	349	.exit = acpi_cpufreq_cpu_exit,
	350	.name = "acpi-cpufreq",
59b2413b	351	.attr = cpufreq_generic_attr,
4db8699b VP	352	};
	353
	354
	355	static int __init
	356	acpi_cpufreq_init (void)
	357	{
2d06d8c4	358	pr_debug("acpi_cpufreq_init\n");
4db8699b VP	359
	360	return cpufreq_register_driver(&acpi_cpufreq_driver);
	361	}
	362
	363
	364	static void __exit
	365	acpi_cpufreq_exit (void)
	366	{
2d06d8c4	367	pr_debug("acpi_cpufreq_exit\n");
4db8699b VP	368
	369	cpufreq_unregister_driver(&acpi_cpufreq_driver);
	370	return;
	371	}
	372
	373
	374	late_initcall(acpi_cpufreq_init);
	375	module_exit(acpi_cpufreq_exit);
	376