[deliverable/linux.git] / drivers / cpufreq / p4-clockmod.c

/*
 *	Pentium 4/Xeon CPU on demand clock modulation/speed scaling
 *	(C) 2002 - 2003 Dominik Brodowski <linux@brodo.de>
 *	(C) 2002 Zwane Mwaikambo <zwane@commfireservices.com>
 *	(C) 2002 Arjan van de Ven <arjanv@redhat.com>
 *	(C) 2002 Tora T. Engstad
 *	All Rights Reserved
 *
 *	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.
 *
 *      The author(s) of this software shall not be held liable for damages
 *      of any nature resulting due to the use of this software. This
 *      software is provided AS-IS with no warranties.
 *
 *	Date		Errata			Description
 *	20020525	N44, O17	12.5% or 25% DC causes lockup
 *
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/smp.h>
#include <linux/cpufreq.h>
#include <linux/cpumask.h>
#include <linux/timex.h>

#include <asm/processor.h>
#include <asm/msr.h>
#include <asm/timer.h>
#include <asm/cpu_device_id.h>

#include "speedstep-lib.h"

#define PFX	"p4-clockmod: "

/*
 * Duty Cycle (3bits), note DC_DISABLE is not specified in
 * intel docs i just use it to mean disable
 */
enum {
	DC_RESV, DC_DFLT, DC_25PT, DC_38PT, DC_50PT,
	DC_64PT, DC_75PT, DC_88PT, DC_DISABLE
};

#define DC_ENTRIES	8


static int has_N44_O17_errata[NR_CPUS];
static unsigned int stock_freq;
static struct cpufreq_driver p4clockmod_driver;
static unsigned int cpufreq_p4_get(unsigned int cpu);

static int cpufreq_p4_setdc(unsigned int cpu, unsigned int newstate)
{
	u32 l, h;

	if (!cpu_online(cpu) ||
	    (newstate > DC_DISABLE) || (newstate == DC_RESV))
		return -EINVAL;

	rdmsr_on_cpu(cpu, MSR_IA32_THERM_STATUS, &l, &h);

	if (l & 0x01)
		pr_debug("CPU#%d currently thermal throttled\n", cpu);

	if (has_N44_O17_errata[cpu] &&
	    (newstate == DC_25PT || newstate == DC_DFLT))
		newstate = DC_38PT;

	rdmsr_on_cpu(cpu, MSR_IA32_THERM_CONTROL, &l, &h);
	if (newstate == DC_DISABLE) {
		pr_debug("CPU#%d disabling modulation\n", cpu);
		wrmsr_on_cpu(cpu, MSR_IA32_THERM_CONTROL, l & ~(1<<4), h);
	} else {
		pr_debug("CPU#%d setting duty cycle to %d%%\n",
			cpu, ((125 * newstate) / 10));
		/* bits 63 - 5	: reserved
		 * bit  4	: enable/disable
		 * bits 3-1	: duty cycle
		 * bit  0	: reserved
		 */
		l = (l & ~14);
		l = l | (1<<4) | ((newstate & 0x7)<<1);
		wrmsr_on_cpu(cpu, MSR_IA32_THERM_CONTROL, l, h);
	}

	return 0;
}


static struct cpufreq_frequency_table p4clockmod_table[] = {
	{DC_RESV, CPUFREQ_ENTRY_INVALID},
	{DC_DFLT, 0},
	{DC_25PT, 0},
	{DC_38PT, 0},
	{DC_50PT, 0},
	{DC_64PT, 0},
	{DC_75PT, 0},
	{DC_88PT, 0},
	{DC_DISABLE, 0},
	{DC_RESV, CPUFREQ_TABLE_END},
};


static int cpufreq_p4_target(struct cpufreq_policy *policy,
			     unsigned int target_freq,
			     unsigned int relation)
{
	unsigned int    newstate = DC_RESV;
	struct cpufreq_freqs freqs;
	int i;

	if (cpufreq_frequency_table_target(policy, &p4clockmod_table[0],
				target_freq, relation, &newstate))
		return -EINVAL;

	freqs.old = cpufreq_p4_get(policy->cpu);
	freqs.new = stock_freq * p4clockmod_table[newstate].index / 8;

	if (freqs.new == freqs.old)
		return 0;

	/* notifiers */
	for_each_cpu(i, policy->cpus) {
		freqs.cpu = i;
		cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
	}

	/* run on each logical CPU,
	 * see section 13.15.3 of IA32 Intel Architecture Software
	 * Developer's Manual, Volume 3
	 */
	for_each_cpu(i, policy->cpus)
		cpufreq_p4_setdc(i, p4clockmod_table[newstate].index);

	/* notifiers */
	for_each_cpu(i, policy->cpus) {
		freqs.cpu = i;
		cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
	}

	return 0;
}


static int cpufreq_p4_verify(struct cpufreq_policy *policy)
{
	return cpufreq_frequency_table_verify(policy, &p4clockmod_table[0]);
}


static unsigned int cpufreq_p4_get_frequency(struct cpuinfo_x86 *c)
{
	if (c->x86 == 0x06) {
		if (cpu_has(c, X86_FEATURE_EST))
			printk_once(KERN_WARNING PFX "Warning: EST-capable "
			       "CPU detected. The acpi-cpufreq module offers "
			       "voltage scaling in addition to frequency "
			       "scaling. You should use that instead of "
			       "p4-clockmod, if possible.\n");
		switch (c->x86_model) {
		case 0x0E: /* Core */
		case 0x0F: /* Core Duo */
		case 0x16: /* Celeron Core */
		case 0x1C: /* Atom */
			p4clockmod_driver.flags |= CPUFREQ_CONST_LOOPS;
			return speedstep_get_frequency(SPEEDSTEP_CPU_PCORE);
		case 0x0D: /* Pentium M (Dothan) */
			p4clockmod_driver.flags |= CPUFREQ_CONST_LOOPS;
			/* fall through */
		case 0x09: /* Pentium M (Banias) */
			return speedstep_get_frequency(SPEEDSTEP_CPU_PM);
		}
	}

	if (c->x86 != 0xF)
		return 0;

	/* on P-4s, the TSC runs with constant frequency independent whether
	 * throttling is active or not. */
	p4clockmod_driver.flags |= CPUFREQ_CONST_LOOPS;

	if (speedstep_detect_processor() == SPEEDSTEP_CPU_P4M) {
		printk(KERN_WARNING PFX "Warning: Pentium 4-M detected. "
		       "The speedstep-ich or acpi cpufreq modules offer "
		       "voltage scaling in addition of frequency scaling. "
		       "You should use either one instead of p4-clockmod, "
		       "if possible.\n");
		return speedstep_get_frequency(SPEEDSTEP_CPU_P4M);
	}

	return speedstep_get_frequency(SPEEDSTEP_CPU_P4D);
}


static int cpufreq_p4_cpu_init(struct cpufreq_policy *policy)
{
	struct cpuinfo_x86 *c = &cpu_data(policy->cpu);
	int cpuid = 0;
	unsigned int i;

#ifdef CONFIG_SMP
	cpumask_copy(policy->cpus, cpu_sibling_mask(policy->cpu));
#endif

	/* Errata workaround */
	cpuid = (c->x86 << 8) | (c->x86_model << 4) | c->x86_mask;
	switch (cpuid) {
	case 0x0f07:
	case 0x0f0a:
	case 0x0f11:
	case 0x0f12:
		has_N44_O17_errata[policy->cpu] = 1;
		pr_debug("has errata -- disabling low frequencies\n");
	}

	if (speedstep_detect_processor() == SPEEDSTEP_CPU_P4D &&
	    c->x86_model < 2) {
		/* switch to maximum frequency and measure result */
		cpufreq_p4_setdc(policy->cpu, DC_DISABLE);
		recalibrate_cpu_khz();
	}
	/* get max frequency */
	stock_freq = cpufreq_p4_get_frequency(c);
	if (!stock_freq)
		return -EINVAL;

	/* table init */
	for (i = 1; (p4clockmod_table[i].frequency != CPUFREQ_TABLE_END); i++) {
		if ((i < 2) && (has_N44_O17_errata[policy->cpu]))
			p4clockmod_table[i].frequency = CPUFREQ_ENTRY_INVALID;
		else
			p4clockmod_table[i].frequency = (stock_freq * i)/8;
	}
	cpufreq_frequency_table_get_attr(p4clockmod_table, policy->cpu);

	/* cpuinfo and default policy values */

	/* the transition latency is set to be 1 higher than the maximum
	 * transition latency of the ondemand governor */
	policy->cpuinfo.transition_latency = 10000001;
	policy->cur = stock_freq;

	return cpufreq_frequency_table_cpuinfo(policy, &p4clockmod_table[0]);
}


static int cpufreq_p4_cpu_exit(struct cpufreq_policy *policy)
{
	cpufreq_frequency_table_put_attr(policy->cpu);
	return 0;
}

static unsigned int cpufreq_p4_get(unsigned int cpu)
{
	u32 l, h;

	rdmsr_on_cpu(cpu, MSR_IA32_THERM_CONTROL, &l, &h);

	if (l & 0x10) {
		l = l >> 1;
		l &= 0x7;
	} else
		l = DC_DISABLE;

	if (l != DC_DISABLE)
		return stock_freq * l / 8;

	return stock_freq;
}

static struct freq_attr *p4clockmod_attr[] = {
	&cpufreq_freq_attr_scaling_available_freqs,
	NULL,
};

static struct cpufreq_driver p4clockmod_driver = {
	.verify		= cpufreq_p4_verify,
	.target		= cpufreq_p4_target,
	.init		= cpufreq_p4_cpu_init,
	.exit		= cpufreq_p4_cpu_exit,
	.get		= cpufreq_p4_get,
	.name		= "p4-clockmod",
	.owner		= THIS_MODULE,
	.attr		= p4clockmod_attr,
};

static const struct x86_cpu_id cpufreq_p4_id[] = {
	{ X86_VENDOR_INTEL, X86_FAMILY_ANY, X86_MODEL_ANY, X86_FEATURE_ACC },
	{}
};

/*
 * Intentionally no MODULE_DEVICE_TABLE here: this driver should not
 * be auto loaded.  Please don't add one.
 */

static int __init cpufreq_p4_init(void)
{
	int ret;

	/*
	 * THERM_CONTROL is architectural for IA32 now, so
	 * we can rely on the capability checks
	 */
	if (!x86_match_cpu(cpufreq_p4_id) || !boot_cpu_has(X86_FEATURE_ACPI))
		return -ENODEV;

	ret = cpufreq_register_driver(&p4clockmod_driver);
	if (!ret)
		printk(KERN_INFO PFX "P4/Xeon(TM) CPU On-Demand Clock "
				"Modulation available\n");

	return ret;
}


static void __exit cpufreq_p4_exit(void)
{
	cpufreq_unregister_driver(&p4clockmod_driver);
}


MODULE_AUTHOR("Zwane Mwaikambo <zwane@commfireservices.com>");
MODULE_DESCRIPTION("cpufreq driver for Pentium(TM) 4/Xeon(TM)");
MODULE_LICENSE("GPL");

late_initcall(cpufreq_p4_init);
module_exit(cpufreq_p4_exit);
Commit	Line	Data
1da177e4 LT	1	/*
	2	* Pentium 4/Xeon CPU on demand clock modulation/speed scaling
	3	* (C) 2002 - 2003 Dominik Brodowski <linux@brodo.de>
	4	* (C) 2002 Zwane Mwaikambo <zwane@commfireservices.com>
	5	* (C) 2002 Arjan van de Ven <arjanv@redhat.com>
	6	* (C) 2002 Tora T. Engstad
	7	* All Rights Reserved
	8	*
	9	* This program is free software; you can redistribute it and/or
	10	* modify it under the terms of the GNU General Public License
	11	* as published by the Free Software Foundation; either version
	12	* 2 of the License, or (at your option) any later version.
	13	*
	14	* The author(s) of this software shall not be held liable for damages
	15	* of any nature resulting due to the use of this software. This
	16	* software is provided AS-IS with no warranties.
32ee8c3e	17	*
1da177e4 LT	18	* Date Errata Description
	19	* 20020525 N44, O17 12.5% or 25% DC causes lockup
	20	*
	21	*/
	22
1da177e4	23	#include <linux/kernel.h>
32ee8c3e	24	#include <linux/module.h>
1da177e4 LT	25	#include <linux/init.h>
	26	#include <linux/smp.h>
	27	#include <linux/cpufreq.h>
1da177e4	28	#include <linux/cpumask.h>
bbfebd66	29	#include <linux/timex.h>
1da177e4	30
32ee8c3e	31	#include <asm/processor.h>
1da177e4	32	#include <asm/msr.h>
199785ea	33	#include <asm/timer.h>
fa8031ae	34	#include <asm/cpu_device_id.h>
1da177e4 LT	35
	36	#include "speedstep-lib.h"
	37
	38	#define PFX "p4-clockmod: "
1da177e4 LT	39
	40	/*
	41	* Duty Cycle (3bits), note DC_DISABLE is not specified in
	42	* intel docs i just use it to mean disable
	43	*/
	44	enum {
	45	DC_RESV, DC_DFLT, DC_25PT, DC_38PT, DC_50PT,
	46	DC_64PT, DC_75PT, DC_88PT, DC_DISABLE
	47	};
	48
	49	#define DC_ENTRIES 8
	50
	51
	52	static int has_N44_O17_errata[NR_CPUS];
	53	static unsigned int stock_freq;
	54	static struct cpufreq_driver p4clockmod_driver;
	55	static unsigned int cpufreq_p4_get(unsigned int cpu);
	56
	57	static int cpufreq_p4_setdc(unsigned int cpu, unsigned int newstate)
	58	{
	59	u32 l, h;
	60
bbfebd66 DJ	61	if (!cpu_online(cpu) \|\|
bbfebd66 DJ	62	(newstate > DC_DISABLE) \|\| (newstate == DC_RESV))
1da177e4 LT	63	return -EINVAL;
1da177e4 LT	64
551948bc	65	rdmsr_on_cpu(cpu, MSR_IA32_THERM_STATUS, &l, &h);
1da177e4 LT	66
1da177e4 LT	67	if (l & 0x01)
2d06d8c4	68	pr_debug("CPU#%d currently thermal throttled\n", cpu);
1da177e4	69
bbfebd66 DJ	70	if (has_N44_O17_errata[cpu] &&
bbfebd66 DJ	71	(newstate == DC_25PT \|\| newstate == DC_DFLT))
1da177e4 LT	72	newstate = DC_38PT;
1da177e4 LT	73
551948bc	74	rdmsr_on_cpu(cpu, MSR_IA32_THERM_CONTROL, &l, &h);
1da177e4	75	if (newstate == DC_DISABLE) {
2d06d8c4	76	pr_debug("CPU#%d disabling modulation\n", cpu);
551948bc	77	wrmsr_on_cpu(cpu, MSR_IA32_THERM_CONTROL, l & ~(1<<4), h);
1da177e4	78	} else {
2d06d8c4	79	pr_debug("CPU#%d setting duty cycle to %d%%\n",
1da177e4	80	cpu, ((125 * newstate) / 10));
32ee8c3e	81	/* bits 63 - 5 : reserved
1da177e4 LT	82	* bit 4 : enable/disable
	83	* bits 3-1 : duty cycle
	84	* bit 0 : reserved
	85	*/
	86	l = (l & ~14);
	87	l = l \| (1<<4) \| ((newstate & 0x7)<<1);
551948bc	88	wrmsr_on_cpu(cpu, MSR_IA32_THERM_CONTROL, l, h);
1da177e4 LT	89	}
	90
	91	return 0;
	92	}
	93
	94
	95	static struct cpufreq_frequency_table p4clockmod_table[] = {
	96	{DC_RESV, CPUFREQ_ENTRY_INVALID},
	97	{DC_DFLT, 0},
	98	{DC_25PT, 0},
	99	{DC_38PT, 0},
	100	{DC_50PT, 0},
	101	{DC_64PT, 0},
	102	{DC_75PT, 0},
	103	{DC_88PT, 0},
	104	{DC_DISABLE, 0},
	105	{DC_RESV, CPUFREQ_TABLE_END},
	106	};
	107
	108
	109	static int cpufreq_p4_target(struct cpufreq_policy *policy,
	110	unsigned int target_freq,
	111	unsigned int relation)
	112	{
	113	unsigned int newstate = DC_RESV;
	114	struct cpufreq_freqs freqs;
1da177e4 LT	115	int i;
1da177e4 LT	116
bbfebd66 DJ	117	if (cpufreq_frequency_table_target(policy, &p4clockmod_table[0],
bbfebd66 DJ	118	target_freq, relation, &newstate))
1da177e4 LT	119	return -EINVAL;
	120
	121	freqs.old = cpufreq_p4_get(policy->cpu);
	122	freqs.new = stock_freq * p4clockmod_table[newstate].index / 8;
	123
	124	if (freqs.new == freqs.old)
	125	return 0;
	126
	127	/* notifiers */
835481d9	128	for_each_cpu(i, policy->cpus) {
1da177e4 LT	129	freqs.cpu = i;
	130	cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
	131	}
	132
bbfebd66 DJ	133	/* run on each logical CPU,
bbfebd66 DJ	134	* see section 13.15.3 of IA32 Intel Architecture Software
32ee8c3e	135	* Developer's Manual, Volume 3
1da177e4	136	*/
835481d9	137	for_each_cpu(i, policy->cpus)
1da177e4	138	cpufreq_p4_setdc(i, p4clockmod_table[newstate].index);
1da177e4 LT	139
1da177e4 LT	140	/* notifiers */
835481d9	141	for_each_cpu(i, policy->cpus) {
1da177e4 LT	142	freqs.cpu = i;
	143	cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
	144	}
	145
	146	return 0;
	147	}
	148
	149
	150	static int cpufreq_p4_verify(struct cpufreq_policy *policy)
	151	{
	152	return cpufreq_frequency_table_verify(policy, &p4clockmod_table[0]);
	153	}
	154
	155
	156	static unsigned int cpufreq_p4_get_frequency(struct cpuinfo_x86 *c)
	157	{
4e74663c DB	158	if (c->x86 == 0x06) {
4e74663c DB	159	if (cpu_has(c, X86_FEATURE_EST))
853cee26 NC	160	printk_once(KERN_WARNING PFX "Warning: EST-capable "
	161	"CPU detected. The acpi-cpufreq module offers "
	162	"voltage scaling in addition to frequency "
bbfebd66 DJ	163	"scaling. You should use that instead of "
bbfebd66 DJ	164	"p4-clockmod, if possible.\n");
4e74663c DB	165	switch (c->x86_model) {
	166	case 0x0E: /* Core */
	167	case 0x0F: /* Core Duo */
8529154e	168	case 0x16: /* Celeron Core */
43195037	169	case 0x1C: /* Atom */
4e74663c	170	p4clockmod_driver.flags \|= CPUFREQ_CONST_LOOPS;
bbfebd66	171	return speedstep_get_frequency(SPEEDSTEP_CPU_PCORE);
4e74663c DB	172	case 0x0D: /* Pentium M (Dothan) */
	173	p4clockmod_driver.flags \|= CPUFREQ_CONST_LOOPS;
	174	/* fall through */
	175	case 0x09: /* Pentium M (Banias) */
bbfebd66	176	return speedstep_get_frequency(SPEEDSTEP_CPU_PM);
4e74663c	177	}
1da177e4 LT	178	}
1da177e4 LT	179
9d1f44ee	180	if (c->x86 != 0xF)
1da177e4	181	return 0;
1da177e4 LT	182
	183	/* on P-4s, the TSC runs with constant frequency independent whether
	184	* throttling is active or not. */
	185	p4clockmod_driver.flags \|= CPUFREQ_CONST_LOOPS;
	186
bbfebd66	187	if (speedstep_detect_processor() == SPEEDSTEP_CPU_P4M) {
1da177e4 LT	188	printk(KERN_WARNING PFX "Warning: Pentium 4-M detected. "
	189	"The speedstep-ich or acpi cpufreq modules offer "
	190	"voltage scaling in addition of frequency scaling. "
	191	"You should use either one instead of p4-clockmod, "
	192	"if possible.\n");
bbfebd66	193	return speedstep_get_frequency(SPEEDSTEP_CPU_P4M);
1da177e4 LT	194	}
1da177e4 LT	195
bbfebd66	196	return speedstep_get_frequency(SPEEDSTEP_CPU_P4D);
1da177e4 LT	197	}
1da177e4 LT	198
32ee8c3e	199
1da177e4 LT	200
	201	static int cpufreq_p4_cpu_init(struct cpufreq_policy *policy)
	202	{
92cb7612	203	struct cpuinfo_x86 *c = &cpu_data(policy->cpu);
1da177e4 LT	204	int cpuid = 0;
	205	unsigned int i;
	206
	207	#ifdef CONFIG_SMP
7ad728f9	208	cpumask_copy(policy->cpus, cpu_sibling_mask(policy->cpu));
1da177e4 LT	209	#endif
	210
	211	/* Errata workaround */
	212	cpuid = (c->x86 << 8) \| (c->x86_model << 4) \| c->x86_mask;
	213	switch (cpuid) {
	214	case 0x0f07:
	215	case 0x0f0a:
	216	case 0x0f11:
	217	case 0x0f12:
	218	has_N44_O17_errata[policy->cpu] = 1;
2d06d8c4	219	pr_debug("has errata -- disabling low frequencies\n");
1da177e4	220	}
32ee8c3e	221
199785ea MCO	222	if (speedstep_detect_processor() == SPEEDSTEP_CPU_P4D &&
	223	c->x86_model < 2) {
	224	/* switch to maximum frequency and measure result */
	225	cpufreq_p4_setdc(policy->cpu, DC_DISABLE);
	226	recalibrate_cpu_khz();
	227	}
1da177e4 LT	228	/* get max frequency */
	229	stock_freq = cpufreq_p4_get_frequency(c);
	230	if (!stock_freq)
	231	return -EINVAL;
	232
	233	/* table init */
bbfebd66 DJ	234	for (i = 1; (p4clockmod_table[i].frequency != CPUFREQ_TABLE_END); i++) {
bbfebd66 DJ	235	if ((i < 2) && (has_N44_O17_errata[policy->cpu]))
1da177e4 LT	236	p4clockmod_table[i].frequency = CPUFREQ_ENTRY_INVALID;
	237	else
	238	p4clockmod_table[i].frequency = (stock_freq * i)/8;
	239	}
	240	cpufreq_frequency_table_get_attr(p4clockmod_table, policy->cpu);
32ee8c3e	241
1da177e4	242	/* cpuinfo and default policy values */
36e8abf3 DJ	243
	244	/* the transition latency is set to be 1 higher than the maximum
	245	* transition latency of the ondemand governor */
	246	policy->cpuinfo.transition_latency = 10000001;
1da177e4 LT	247	policy->cur = stock_freq;
	248
	249	return cpufreq_frequency_table_cpuinfo(policy, &p4clockmod_table[0]);
	250	}
	251
	252
	253	static int cpufreq_p4_cpu_exit(struct cpufreq_policy *policy)
	254	{
32ee8c3e	255	cpufreq_frequency_table_put_attr(policy->cpu);
1da177e4 LT	256	return 0;
	257	}
	258
	259	static unsigned int cpufreq_p4_get(unsigned int cpu)
	260	{
1da177e4 LT	261	u32 l, h;
1da177e4 LT	262
551948bc	263	rdmsr_on_cpu(cpu, MSR_IA32_THERM_CONTROL, &l, &h);
1da177e4 LT	264
	265	if (l & 0x10) {
	266	l = l >> 1;
	267	l &= 0x7;
	268	} else
	269	l = DC_DISABLE;
	270
	271	if (l != DC_DISABLE)
bbfebd66	272	return stock_freq * l / 8;
1da177e4 LT	273
	274	return stock_freq;
	275	}
	276
bbfebd66	277	static struct freq_attr *p4clockmod_attr[] = {
1da177e4 LT	278	&cpufreq_freq_attr_scaling_available_freqs,
	279	NULL,
	280	};
	281
	282	static struct cpufreq_driver p4clockmod_driver = {
32ee8c3e	283	.verify = cpufreq_p4_verify,
1da177e4 LT	284	.target = cpufreq_p4_target,
	285	.init = cpufreq_p4_cpu_init,
	286	.exit = cpufreq_p4_cpu_exit,
	287	.get = cpufreq_p4_get,
	288	.name = "p4-clockmod",
	289	.owner = THIS_MODULE,
	290	.attr = p4clockmod_attr,
	291	};
	292
fa8031ae AK	293	static const struct x86_cpu_id cpufreq_p4_id[] = {
	294	{ X86_VENDOR_INTEL, X86_FAMILY_ANY, X86_MODEL_ANY, X86_FEATURE_ACC },
	295	{}
	296	};
	297
	298	/*
	299	* Intentionally no MODULE_DEVICE_TABLE here: this driver should not
	300	* be auto loaded. Please don't add one.
	301	*/
1da177e4 LT	302
1da177e4 LT	303	static int __init cpufreq_p4_init(void)
32ee8c3e	304	{
1da177e4 LT	305	int ret;
	306
	307	/*
32ee8c3e	308	* THERM_CONTROL is architectural for IA32 now, so
1da177e4 LT	309	* we can rely on the capability checks
1da177e4 LT	310	*/
fa8031ae	311	if (!x86_match_cpu(cpufreq_p4_id) \|\| !boot_cpu_has(X86_FEATURE_ACPI))
1da177e4 LT	312	return -ENODEV;
	313
	314	ret = cpufreq_register_driver(&p4clockmod_driver);
	315	if (!ret)
bbfebd66 DJ	316	printk(KERN_INFO PFX "P4/Xeon(TM) CPU On-Demand Clock "
bbfebd66 DJ	317	"Modulation available\n");
1da177e4	318
bbfebd66	319	return ret;
1da177e4 LT	320	}
	321
	322
	323	static void __exit cpufreq_p4_exit(void)
	324	{
	325	cpufreq_unregister_driver(&p4clockmod_driver);
	326	}
	327
	328
bbfebd66 DJ	329	MODULE_AUTHOR("Zwane Mwaikambo <zwane@commfireservices.com>");
	330	MODULE_DESCRIPTION("cpufreq driver for Pentium(TM) 4/Xeon(TM)");
	331	MODULE_LICENSE("GPL");
1da177e4 LT	332
	333	late_initcall(cpufreq_p4_init);
	334	module_exit(cpufreq_p4_exit);