[people/ms/linux.git] / arch / i386 / kernel / cpu / cpufreq / acpi-cpufreq.c

/*
 * acpi-cpufreq.c - ACPI Processor P-States Driver ($Revision: 1.3 $)
 *
 *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
 *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
 *  Copyright (C) 2002 - 2004 Dominik Brodowski <linux@brodo.de>
 *
 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or (at
 *  your option) any later version.
 *
 *  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.
 *
 *  You should have received a copy of the GNU General Public License along
 *  with this program; if not, write to the Free Software Foundation, Inc.,
 *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
 *
 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 */

#include <linux/config.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/cpufreq.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/compiler.h>
#include <linux/sched.h>	/* current */
#include <asm/io.h>
#include <asm/delay.h>
#include <asm/uaccess.h>

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

#define dprintk(msg...) cpufreq_debug_printk(CPUFREQ_DEBUG_DRIVER, "acpi-cpufreq", msg)

MODULE_AUTHOR("Paul Diefenbaugh, Dominik Brodowski");
MODULE_DESCRIPTION("ACPI Processor P-States Driver");
MODULE_LICENSE("GPL");


struct cpufreq_acpi_io {
	struct acpi_processor_performance	acpi_data;
	struct cpufreq_frequency_table		*freq_table;
	unsigned int				resume;
};

static struct cpufreq_acpi_io	*acpi_io_data[NR_CPUS];

static struct cpufreq_driver acpi_cpufreq_driver;

static unsigned int acpi_pstate_strict;

static int
acpi_processor_write_port(
	u16	port,
	u8	bit_width,
	u32	value)
{
	if (bit_width <= 8) {
		outb(value, port);
	} else if (bit_width <= 16) {
		outw(value, port);
	} else if (bit_width <= 32) {
		outl(value, port);
	} else {
		return -ENODEV;
	}
	return 0;
}

static int
acpi_processor_read_port(
	u16	port,
	u8	bit_width,
	u32	*ret)
{
	*ret = 0;
	if (bit_width <= 8) {
		*ret = inb(port);
	} else if (bit_width <= 16) {
		*ret = inw(port);
	} else if (bit_width <= 32) {
		*ret = inl(port);
	} else {
		return -ENODEV;
	}
	return 0;
}

static int
acpi_processor_set_performance (
	struct cpufreq_acpi_io	*data,
	unsigned int		cpu,
	int			state)
{
	u16			port = 0;
	u8			bit_width = 0;
	int			ret = 0;
	u32			value = 0;
	int			i = 0;
	struct cpufreq_freqs    cpufreq_freqs;
	cpumask_t		saved_mask;
	int			retval;

	dprintk("acpi_processor_set_performance\n");

	/*
	 * TBD: Use something other than set_cpus_allowed.
	 * As set_cpus_allowed is a bit racy, 
	 * with any other set_cpus_allowed for this process.
	 */
	saved_mask = current->cpus_allowed;
	set_cpus_allowed(current, cpumask_of_cpu(cpu));
	if (smp_processor_id() != cpu) {
		return (-EAGAIN);
	}
	
	if (state == data->acpi_data.state) {
		if (unlikely(data->resume)) {
			dprintk("Called after resume, resetting to P%d\n", state);
			data->resume = 0;
		} else {
			dprintk("Already at target state (P%d)\n", state);
			retval = 0;
			goto migrate_end;
		}
	}

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

	/* cpufreq frequency struct */
	cpufreq_freqs.cpu = cpu;
	cpufreq_freqs.old = data->freq_table[data->acpi_data.state].frequency;
	cpufreq_freqs.new = data->freq_table[state].frequency;

	/* notify cpufreq */
	cpufreq_notify_transition(&cpufreq_freqs, CPUFREQ_PRECHANGE);

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

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

	dprintk("Writing 0x%08x to port 0x%04x\n", value, port);

	ret = acpi_processor_write_port(port, bit_width, value);
	if (ret) {
		dprintk("Invalid port width 0x%04x\n", bit_width);
		retval = ret;
		goto migrate_end;
	}

	/*
	 * Assume the write went through when acpi_pstate_strict is not used.
	 * As read status_register is an expensive operation and there 
	 * are no specific error cases where an IO port write will fail.
	 */
	if (acpi_pstate_strict) {
		/* Then we read the 'status_register' and compare the value 
		 * with the target state's 'status' to make sure the 
		 * transition was successful.
		 * Note that we'll poll for up to 1ms (100 cycles of 10us) 
		 * before giving up.
		 */

		port = data->acpi_data.status_register.address;
		bit_width = data->acpi_data.status_register.bit_width;

		dprintk("Looking for 0x%08x from port 0x%04x\n",
			(u32) data->acpi_data.states[state].status, port);

		for (i=0; i<100; i++) {
			ret = acpi_processor_read_port(port, bit_width, &value);
			if (ret) {	
				dprintk("Invalid port width 0x%04x\n", bit_width);
				retval = ret;
				goto migrate_end;
			}
			if (value == (u32) data->acpi_data.states[state].status)
				break;
			udelay(10);
		}
	} else {
		i = 0;
		value = (u32) data->acpi_data.states[state].status;
	}

	/* notify cpufreq */
	cpufreq_notify_transition(&cpufreq_freqs, CPUFREQ_POSTCHANGE);

	if (unlikely(value != (u32) data->acpi_data.states[state].status)) {
		unsigned int tmp = cpufreq_freqs.new;
		cpufreq_freqs.new = cpufreq_freqs.old;
		cpufreq_freqs.old = tmp;
		cpufreq_notify_transition(&cpufreq_freqs, CPUFREQ_PRECHANGE);
		cpufreq_notify_transition(&cpufreq_freqs, CPUFREQ_POSTCHANGE);
		printk(KERN_WARNING "acpi-cpufreq: Transition failed\n");
		retval = -ENODEV;
		goto migrate_end;
	}

	dprintk("Transition successful after %d microseconds\n", i * 10);

	data->acpi_data.state = state;

	retval = 0;
migrate_end:
	set_cpus_allowed(current, saved_mask);
	return (retval);
}


static int
acpi_cpufreq_target (
	struct cpufreq_policy   *policy,
	unsigned int target_freq,
	unsigned int relation)
{
	struct cpufreq_acpi_io *data = acpi_io_data[policy->cpu];
	unsigned int next_state = 0;
	unsigned int result = 0;

	dprintk("acpi_cpufreq_setpolicy\n");

	result = cpufreq_frequency_table_target(policy,
			data->freq_table,
			target_freq,
			relation,
			&next_state);
	if (result)
		return (result);

	result = acpi_processor_set_performance (data, policy->cpu, next_state);

	return (result);
}


static int
acpi_cpufreq_verify (
	struct cpufreq_policy   *policy)
{
	unsigned int result = 0;
	struct cpufreq_acpi_io *data = acpi_io_data[policy->cpu];

	dprintk("acpi_cpufreq_verify\n");

	result = cpufreq_frequency_table_verify(policy, 
			data->freq_table);

	return (result);
}


static unsigned long
acpi_cpufreq_guess_freq (
	struct cpufreq_acpi_io	*data,
	unsigned int		cpu)
{
	if (cpu_khz) {
		/* search the closest match to cpu_khz */
		unsigned int i;
		unsigned long freq;
		unsigned long freqn = data->acpi_data.states[0].core_frequency * 1000;

		for (i=0; i < (data->acpi_data.state_count - 1); i++) {
			freq = freqn;
			freqn = data->acpi_data.states[i+1].core_frequency * 1000;
			if ((2 * cpu_khz) > (freqn + freq)) {
				data->acpi_data.state = i;
				return (freq);
			}
		}
		data->acpi_data.state = data->acpi_data.state_count - 1;
		return (freqn);
	} else
		/* assume CPU is at P0... */
		data->acpi_data.state = 0;
		return data->acpi_data.states[0].core_frequency * 1000;
	
}


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 cpuinfo_x86 *c = &cpu_data[policy->cpu];

	dprintk("acpi_cpufreq_cpu_init\n");

	data = kzalloc(sizeof(struct cpufreq_acpi_io), 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;

	if (cpu_has(c, X86_FEATURE_CONSTANT_TSC)) {
		acpi_cpufreq_driver.flags |= CPUFREQ_CONST_LOOPS;
	}

	/* capability check */
	if (data->acpi_data.state_count <= 1) {
		dprintk("No P-States\n");
		result = -ENODEV;
		goto err_unreg;
	}
	if ((data->acpi_data.control_register.space_id != ACPI_ADR_SPACE_SYSTEM_IO) ||
	    (data->acpi_data.status_register.space_id != ACPI_ADR_SPACE_SYSTEM_IO)) {
		dprintk("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 */
	data->freq_table = kmalloc(sizeof(struct cpufreq_frequency_table) * (data->acpi_data.state_count + 1), GFP_KERNEL);
	if (!data->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;
	}
	policy->governor = CPUFREQ_DEFAULT_GOVERNOR;

	/* The current speed is unknown and not detectable by ACPI...  */
	policy->cur = acpi_cpufreq_guess_freq(data, policy->cpu);

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

	result = cpufreq_frequency_table_cpuinfo(policy, data->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++)
		dprintk("     %cP%d: %d MHz, %d mW, %d uS\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);

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

 err_freqfree:
	kfree(data->freq_table);
 err_unreg:
	acpi_processor_unregister_performance(&data->acpi_data, 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];


	dprintk("acpi_cpufreq_cpu_exit\n");

	if (data) {
		cpufreq_frequency_table_put_attr(policy->cpu);
		acpi_io_data[policy->cpu] = NULL;
		acpi_processor_unregister_performance(&data->acpi_data, policy->cpu);
		kfree(data);
	}

	return (0);
}

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


	dprintk("acpi_cpufreq_resume\n");

	data->resume = 1;

	return (0);
}


static struct freq_attr* acpi_cpufreq_attr[] = {
	&cpufreq_freq_attr_scaling_available_freqs,
	NULL,
};

static struct cpufreq_driver acpi_cpufreq_driver = {
	.verify 	= acpi_cpufreq_verify,
	.target 	= acpi_cpufreq_target,
	.init		= acpi_cpufreq_cpu_init,
	.exit		= acpi_cpufreq_cpu_exit,
	.resume		= acpi_cpufreq_resume,
	.name		= "acpi-cpufreq",
	.owner		= THIS_MODULE,
	.attr           = acpi_cpufreq_attr,
};


static int __init
acpi_cpufreq_init (void)
{
	int                     result = 0;

	dprintk("acpi_cpufreq_init\n");

 	result = cpufreq_register_driver(&acpi_cpufreq_driver);
	
	return (result);
}


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

	cpufreq_unregister_driver(&acpi_cpufreq_driver);

	return;
}

module_param(acpi_pstate_strict, uint, 0644);
MODULE_PARM_DESC(acpi_pstate_strict, "value 0 or non-zero. non-zero -> strict ACPI checks are performed during frequency changes.");

late_initcall(acpi_cpufreq_init);
module_exit(acpi_cpufreq_exit);

MODULE_ALIAS("acpi");
Commit	Line	Data
1da177e4 LT	1	/*
	2	* acpi-cpufreq.c - ACPI Processor P-States Driver ($Revision: 1.3 $)
	3	*
	4	* Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
	5	* Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
	6	* Copyright (C) 2002 - 2004 Dominik Brodowski <linux@brodo.de>
	7	*
	8	* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
	9	*
	10	* This program is free software; you can redistribute it and/or modify
	11	* it under the terms of the GNU General Public License as published by
	12	* the Free Software Foundation; either version 2 of the License, or (at
	13	* your option) any later version.
	14	*
	15	* This program is distributed in the hope that it will be useful, but
	16	* WITHOUT ANY WARRANTY; without even the implied warranty of
	17	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	18	* General Public License for more details.
	19	*
	20	* You should have received a copy of the GNU General Public License along
	21	* with this program; if not, write to the Free Software Foundation, Inc.,
	22	* 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
	23	*
	24	* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
	25	*/
	26
	27	#include <linux/config.h>
	28	#include <linux/kernel.h>
	29	#include <linux/module.h>
	30	#include <linux/init.h>
	31	#include <linux/cpufreq.h>
	32	#include <linux/proc_fs.h>
	33	#include <linux/seq_file.h>
d395bf12	34	#include <linux/compiler.h>
4e57b681	35	#include <linux/sched.h> /* current */
1da177e4 LT	36	#include <asm/io.h>
	37	#include <asm/delay.h>
	38	#include <asm/uaccess.h>
	39
	40	#include <linux/acpi.h>
	41	#include <acpi/processor.h>
	42
1da177e4 LT	43	#define dprintk(msg...) cpufreq_debug_printk(CPUFREQ_DEBUG_DRIVER, "acpi-cpufreq", msg)
	44
	45	MODULE_AUTHOR("Paul Diefenbaugh, Dominik Brodowski");
	46	MODULE_DESCRIPTION("ACPI Processor P-States Driver");
	47	MODULE_LICENSE("GPL");
	48
	49
	50	struct cpufreq_acpi_io {
	51	struct acpi_processor_performance acpi_data;
	52	struct cpufreq_frequency_table *freq_table;
	53	unsigned int resume;
	54	};
	55
	56	static struct cpufreq_acpi_io *acpi_io_data[NR_CPUS];
	57
	58	static struct cpufreq_driver acpi_cpufreq_driver;
	59
d395bf12 VP	60	static unsigned int acpi_pstate_strict;
d395bf12 VP	61
1da177e4 LT	62	static int
	63	acpi_processor_write_port(
	64	u16 port,
	65	u8 bit_width,
	66	u32 value)
	67	{
	68	if (bit_width <= 8) {
	69	outb(value, port);
	70	} else if (bit_width <= 16) {
	71	outw(value, port);
	72	} else if (bit_width <= 32) {
	73	outl(value, port);
	74	} else {
	75	return -ENODEV;
	76	}
	77	return 0;
	78	}
	79
	80	static int
	81	acpi_processor_read_port(
	82	u16 port,
	83	u8 bit_width,
	84	u32 *ret)
	85	{
	86	*ret = 0;
	87	if (bit_width <= 8) {
	88	*ret = inb(port);
	89	} else if (bit_width <= 16) {
	90	*ret = inw(port);
	91	} else if (bit_width <= 32) {
	92	*ret = inl(port);
	93	} else {
	94	return -ENODEV;
	95	}
	96	return 0;
	97	}
	98
	99	static int
	100	acpi_processor_set_performance (
	101	struct cpufreq_acpi_io *data,
	102	unsigned int cpu,
	103	int state)
	104	{
	105	u16 port = 0;
	106	u8 bit_width = 0;
	107	int ret = 0;
	108	u32 value = 0;
	109	int i = 0;
	110	struct cpufreq_freqs cpufreq_freqs;
	111	cpumask_t saved_mask;
	112	int retval;
	113
	114	dprintk("acpi_processor_set_performance\n");
	115
	116	/*
	117	* TBD: Use something other than set_cpus_allowed.
	118	* As set_cpus_allowed is a bit racy,
	119	* with any other set_cpus_allowed for this process.
	120	*/
	121	saved_mask = current->cpus_allowed;
	122	set_cpus_allowed(current, cpumask_of_cpu(cpu));
	123	if (smp_processor_id() != cpu) {
	124	return (-EAGAIN);
	125	}
126
127	if (state == data->acpi_data.state) {
128	if (unlikely(data->resume)) {
129	dprintk("Called after resume, resetting to P%d\n", state);
130	data->resume = 0;
131	} else {
132	dprintk("Already at target state (P%d)\n", state);
133	retval = 0;
134	goto migrate_end;
135	}
136	}
137
138	dprintk("Transitioning from P%d to P%d\n",
139	data->acpi_data.state, state);
140
141	/* cpufreq frequency struct */
142	cpufreq_freqs.cpu = cpu;
143	cpufreq_freqs.old = data->freq_table[data->acpi_data.state].frequency;
144	cpufreq_freqs.new = data->freq_table[state].frequency;
145
146	/* notify cpufreq */
147	cpufreq_notify_transition(&cpufreq_freqs, CPUFREQ_PRECHANGE);
148
149	/*
150	* First we write the target state's 'control' value to the
151	* control_register.
152	*/
153
154	port = data->acpi_data.control_register.address;
155	bit_width = data->acpi_data.control_register.bit_width;
156	value = (u32) data->acpi_data.states[state].control;
157
158	dprintk("Writing 0x%08x to port 0x%04x\n", value, port);
159
160	ret = acpi_processor_write_port(port, bit_width, value);
161	if (ret) {
162	dprintk("Invalid port width 0x%04x\n", bit_width);
163	retval = ret;
164	goto migrate_end;
165	}
166
167	/*
d395bf12 VP	168	* Assume the write went through when acpi_pstate_strict is not used.
	169	* As read status_register is an expensive operation and there
	170	* are no specific error cases where an IO port write will fail.
1da177e4	171	*/
d395bf12 VP	172	if (acpi_pstate_strict) {
	173	/* Then we read the 'status_register' and compare the value
	174	* with the target state's 'status' to make sure the
	175	* transition was successful.
	176	* Note that we'll poll for up to 1ms (100 cycles of 10us)
	177	* before giving up.
	178	*/
	179
	180	port = data->acpi_data.status_register.address;
	181	bit_width = data->acpi_data.status_register.bit_width;
	182
	183	dprintk("Looking for 0x%08x from port 0x%04x\n",
	184	(u32) data->acpi_data.states[state].status, port);
	185
	186	for (i=0; i<100; i++) {
	187	ret = acpi_processor_read_port(port, bit_width, &value);
	188	if (ret) {
	189	dprintk("Invalid port width 0x%04x\n", bit_width);
	190	retval = ret;
	191	goto migrate_end;
	192	}
	193	if (value == (u32) data->acpi_data.states[state].status)
	194	break;
	195	udelay(10);
1da177e4	196	}
d395bf12 VP	197	} else {
	198	i = 0;
	199	value = (u32) data->acpi_data.states[state].status;
1da177e4 LT	200	}
	201
	202	/* notify cpufreq */
	203	cpufreq_notify_transition(&cpufreq_freqs, CPUFREQ_POSTCHANGE);
	204
d395bf12	205	if (unlikely(value != (u32) data->acpi_data.states[state].status)) {
1da177e4 LT	206	unsigned int tmp = cpufreq_freqs.new;
	207	cpufreq_freqs.new = cpufreq_freqs.old;
	208	cpufreq_freqs.old = tmp;
	209	cpufreq_notify_transition(&cpufreq_freqs, CPUFREQ_PRECHANGE);
	210	cpufreq_notify_transition(&cpufreq_freqs, CPUFREQ_POSTCHANGE);
	211	printk(KERN_WARNING "acpi-cpufreq: Transition failed\n");
	212	retval = -ENODEV;
	213	goto migrate_end;
	214	}
	215
	216	dprintk("Transition successful after %d microseconds\n", i * 10);
	217
	218	data->acpi_data.state = state;
	219
	220	retval = 0;
	221	migrate_end:
	222	set_cpus_allowed(current, saved_mask);
	223	return (retval);
	224	}
	225
	226
	227	static int
	228	acpi_cpufreq_target (
	229	struct cpufreq_policy *policy,
	230	unsigned int target_freq,
	231	unsigned int relation)
	232	{
	233	struct cpufreq_acpi_io *data = acpi_io_data[policy->cpu];
	234	unsigned int next_state = 0;
	235	unsigned int result = 0;
	236
	237	dprintk("acpi_cpufreq_setpolicy\n");
	238
	239	result = cpufreq_frequency_table_target(policy,
	240	data->freq_table,
	241	target_freq,
	242	relation,
	243	&next_state);
	244	if (result)
	245	return (result);
	246
	247	result = acpi_processor_set_performance (data, policy->cpu, next_state);
	248
	249	return (result);
	250	}
	251
	252
	253	static int
	254	acpi_cpufreq_verify (
	255	struct cpufreq_policy *policy)
	256	{
	257	unsigned int result = 0;
	258	struct cpufreq_acpi_io *data = acpi_io_data[policy->cpu];
	259
	260	dprintk("acpi_cpufreq_verify\n");
	261
	262	result = cpufreq_frequency_table_verify(policy,
	263	data->freq_table);
	264
	265	return (result);
	266	}
	267
	268
	269	static unsigned long
270	acpi_cpufreq_guess_freq (
271	struct cpufreq_acpi_io *data,
272	unsigned int cpu)
273	{
274	if (cpu_khz) {
275	/* search the closest match to cpu_khz */
276	unsigned int i;
277	unsigned long freq;
278	unsigned long freqn = data->acpi_data.states[0].core_frequency * 1000;
279
280	for (i=0; i < (data->acpi_data.state_count - 1); i++) {
281	freq = freqn;
282	freqn = data->acpi_data.states[i+1].core_frequency * 1000;
283	if ((2 * cpu_khz) > (freqn + freq)) {
284	data->acpi_data.state = i;
285	return (freq);
286	}
287	}
288	data->acpi_data.state = data->acpi_data.state_count - 1;
289	return (freqn);
290	} else
291	/* assume CPU is at P0... */
292	data->acpi_data.state = 0;
293	return data->acpi_data.states[0].core_frequency * 1000;
294
295	}
296
297
1da177e4 LT	298	static int
	299	acpi_cpufreq_cpu_init (
	300	struct cpufreq_policy *policy)
	301	{
	302	unsigned int i;
	303	unsigned int cpu = policy->cpu;
	304	struct cpufreq_acpi_io *data;
	305	unsigned int result = 0;
152bf8c5	306	struct cpuinfo_x86 *c = &cpu_data[policy->cpu];
1da177e4	307
1da177e4	308	dprintk("acpi_cpufreq_cpu_init\n");
1da177e4	309
bfdc708d	310	data = kzalloc(sizeof(struct cpufreq_acpi_io), GFP_KERNEL);
1da177e4 LT	311	if (!data)
1da177e4 LT	312	return (-ENOMEM);
1da177e4 LT	313
	314	acpi_io_data[cpu] = data;
	315
1da177e4	316	result = acpi_processor_register_performance(&data->acpi_data, cpu);
1da177e4 LT	317
	318	if (result)
	319	goto err_free;
	320
152bf8c5	321	if (cpu_has(c, X86_FEATURE_CONSTANT_TSC)) {
1da177e4 LT	322	acpi_cpufreq_driver.flags \|= CPUFREQ_CONST_LOOPS;
	323	}
	324
	325	/* capability check */
	326	if (data->acpi_data.state_count <= 1) {
	327	dprintk("No P-States\n");
	328	result = -ENODEV;
	329	goto err_unreg;
	330	}
	331	if ((data->acpi_data.control_register.space_id != ACPI_ADR_SPACE_SYSTEM_IO) \|\|
	332	(data->acpi_data.status_register.space_id != ACPI_ADR_SPACE_SYSTEM_IO)) {
	333	dprintk("Unsupported address space [%d, %d]\n",
	334	(u32) (data->acpi_data.control_register.space_id),
	335	(u32) (data->acpi_data.status_register.space_id));
	336	result = -ENODEV;
	337	goto err_unreg;
	338	}
	339
	340	/* alloc freq_table */
	341	data->freq_table = kmalloc(sizeof(struct cpufreq_frequency_table) * (data->acpi_data.state_count + 1), GFP_KERNEL);
	342	if (!data->freq_table) {
	343	result = -ENOMEM;
	344	goto err_unreg;
	345	}
	346
	347	/* detect transition latency */
	348	policy->cpuinfo.transition_latency = 0;
	349	for (i=0; i<data->acpi_data.state_count; i++) {
	350	if ((data->acpi_data.states[i].transition_latency * 1000) > policy->cpuinfo.transition_latency)
	351	policy->cpuinfo.transition_latency = data->acpi_data.states[i].transition_latency * 1000;
	352	}
	353	policy->governor = CPUFREQ_DEFAULT_GOVERNOR;
	354
	355	/* The current speed is unknown and not detectable by ACPI... */
	356	policy->cur = acpi_cpufreq_guess_freq(data, policy->cpu);
	357
	358	/* table init */
	359	for (i=0; i<=data->acpi_data.state_count; i++)
	360	{
	361	data->freq_table[i].index = i;
	362	if (i<data->acpi_data.state_count)
	363	data->freq_table[i].frequency = data->acpi_data.states[i].core_frequency * 1000;
	364	else
	365	data->freq_table[i].frequency = CPUFREQ_TABLE_END;
	366	}
	367
	368	result = cpufreq_frequency_table_cpuinfo(policy, data->freq_table);
	369	if (result) {
	370	goto err_freqfree;
	371	}
	372
	373	/* notify BIOS that we exist */
	374	acpi_processor_notify_smm(THIS_MODULE);
	375
	376	printk(KERN_INFO "acpi-cpufreq: CPU%u - ACPI performance management activated.\n",
	377	cpu);
	378	for (i = 0; i < data->acpi_data.state_count; i++)
	379	dprintk(" %cP%d: %d MHz, %d mW, %d uS\n",
	380	(i == data->acpi_data.state?'*':' '), i,
	381	(u32) data->acpi_data.states[i].core_frequency,
	382	(u32) data->acpi_data.states[i].power,
	383	(u32) data->acpi_data.states[i].transition_latency);
	384
	385	cpufreq_frequency_table_get_attr(data->freq_table, policy->cpu);
4b31e774 DB	386
	387	/*
	388	* the first call to ->target() should result in us actually
	389	* writing something to the appropriate registers.
	390	*/
	391	data->resume = 1;
	392
1da177e4 LT	393	return (result);
	394
	395	err_freqfree:
	396	kfree(data->freq_table);
	397	err_unreg:
	398	acpi_processor_unregister_performance(&data->acpi_data, cpu);
	399	err_free:
	400	kfree(data);
	401	acpi_io_data[cpu] = NULL;
	402
	403	return (result);
	404	}
	405
	406
	407	static int
	408	acpi_cpufreq_cpu_exit (
	409	struct cpufreq_policy *policy)
	410	{
	411	struct cpufreq_acpi_io *data = acpi_io_data[policy->cpu];
	412
	413
	414	dprintk("acpi_cpufreq_cpu_exit\n");
	415
	416	if (data) {
	417	cpufreq_frequency_table_put_attr(policy->cpu);
	418	acpi_io_data[policy->cpu] = NULL;
	419	acpi_processor_unregister_performance(&data->acpi_data, policy->cpu);
	420	kfree(data);
	421	}
	422
	423	return (0);
	424	}
	425
	426	static int
	427	acpi_cpufreq_resume (
	428	struct cpufreq_policy *policy)
	429	{
	430	struct cpufreq_acpi_io *data = acpi_io_data[policy->cpu];
	431
	432
	433	dprintk("acpi_cpufreq_resume\n");
	434
	435	data->resume = 1;
	436
	437	return (0);
	438	}
	439
	440
	441	static struct freq_attr* acpi_cpufreq_attr[] = {
	442	&cpufreq_freq_attr_scaling_available_freqs,
	443	NULL,
	444	};
	445
	446	static struct cpufreq_driver acpi_cpufreq_driver = {
	447	.verify = acpi_cpufreq_verify,
	448	.target = acpi_cpufreq_target,
	449	.init = acpi_cpufreq_cpu_init,
	450	.exit = acpi_cpufreq_cpu_exit,
	451	.resume = acpi_cpufreq_resume,
	452	.name = "acpi-cpufreq",
	453	.owner = THIS_MODULE,
	454	.attr = acpi_cpufreq_attr,
	455	};
	456
457
458	static int __init
459	acpi_cpufreq_init (void)
460	{
461	int result = 0;
462
463	dprintk("acpi_cpufreq_init\n");
464
465	result = cpufreq_register_driver(&acpi_cpufreq_driver);
466
467	return (result);
468	}
469
470
471	static void __exit
472	acpi_cpufreq_exit (void)
473	{
474	dprintk("acpi_cpufreq_exit\n");
475
476	cpufreq_unregister_driver(&acpi_cpufreq_driver);
477
478	return;
479	}
480
d395bf12 VP	481	module_param(acpi_pstate_strict, uint, 0644);
d395bf12 VP	482	MODULE_PARM_DESC(acpi_pstate_strict, "value 0 or non-zero. non-zero -> strict ACPI checks are performed during frequency changes.");
1da177e4 LT	483
	484	late_initcall(acpi_cpufreq_init);
	485	module_exit(acpi_cpufreq_exit);
	486
	487	MODULE_ALIAS("acpi");