[linux-2.6-block.git] / drivers / cpufreq / speedstep-smi.c

/*
 * Intel SpeedStep SMI driver.
 *
 * (C) 2003  Hiroshi Miura <miura@da-cha.org>
 *
 *  Licensed under the terms of the GNU GPL License version 2.
 *
 */


/*********************************************************************
 *                        SPEEDSTEP - DEFINITIONS                    *
 *********************************************************************/

#define pr_fmt(fmt) "cpufreq: " fmt

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/init.h>
#include <linux/cpufreq.h>
#include <linux/delay.h>
#include <linux/io.h>
#include <asm/ist.h>
#include <asm/cpu_device_id.h>

#include "speedstep-lib.h"

/* speedstep system management interface port/command.
 *
 * These parameters are got from IST-SMI BIOS call.
 * If user gives it, these are used.
 *
 */
static int smi_port;
static int smi_cmd;
static unsigned int smi_sig;

/* info about the processor */
static enum speedstep_processor speedstep_processor;

/*
 * There are only two frequency states for each processor. Values
 * are in kHz for the time being.
 */
static struct cpufreq_frequency_table speedstep_freqs[] = {
	{0, SPEEDSTEP_HIGH,	0},
	{0, SPEEDSTEP_LOW,	0},
	{0, 0,			CPUFREQ_TABLE_END},
};

#define GET_SPEEDSTEP_OWNER 0
#define GET_SPEEDSTEP_STATE 1
#define SET_SPEEDSTEP_STATE 2
#define GET_SPEEDSTEP_FREQS 4

/* how often shall the SMI call be tried if it failed, e.g. because
 * of DMA activity going on? */
#define SMI_TRIES 5

/**
 * speedstep_smi_ownership
 */
static int speedstep_smi_ownership(void)
{
	u32 command, result, magic, dummy;
	u32 function = GET_SPEEDSTEP_OWNER;
	unsigned char magic_data[] = "Copyright (c) 1999 Intel Corporation";

	command = (smi_sig & 0xffffff00) | (smi_cmd & 0xff);
	magic = virt_to_phys(magic_data);

	pr_debug("trying to obtain ownership with command %x at port %x\n",
			command, smi_port);

	__asm__ __volatile__(
		"push %%ebp\n"
		"out %%al, (%%dx)\n"
		"pop %%ebp\n"
		: "=D" (result),
		  "=a" (dummy), "=b" (dummy), "=c" (dummy), "=d" (dummy),
		  "=S" (dummy)
		: "a" (command), "b" (function), "c" (0), "d" (smi_port),
		  "D" (0), "S" (magic)
		: "memory"
	);

	pr_debug("result is %x\n", result);

	return result;
}

/**
 * speedstep_smi_get_freqs - get SpeedStep preferred & current freq.
 * @low: the low frequency value is placed here
 * @high: the high frequency value is placed here
 *
 * Only available on later SpeedStep-enabled systems, returns false results or
 * even hangs [cf. bugme.osdl.org # 1422] on earlier systems. Empirical testing
 * shows that the latter occurs if !(ist_info.event & 0xFFFF).
 */
static int speedstep_smi_get_freqs(unsigned int *low, unsigned int *high)
{
	u32 command, result = 0, edi, high_mhz, low_mhz, dummy;
	u32 state = 0;
	u32 function = GET_SPEEDSTEP_FREQS;

	if (!(ist_info.event & 0xFFFF)) {
		pr_debug("bug #1422 -- can't read freqs from BIOS\n");
		return -ENODEV;
	}

	command = (smi_sig & 0xffffff00) | (smi_cmd & 0xff);

	pr_debug("trying to determine frequencies with command %x at port %x\n",
			command, smi_port);

	__asm__ __volatile__(
		"push %%ebp\n"
		"out %%al, (%%dx)\n"
		"pop %%ebp"
		: "=a" (result),
		  "=b" (high_mhz),
		  "=c" (low_mhz),
		  "=d" (state), "=D" (edi), "=S" (dummy)
		: "a" (command),
		  "b" (function),
		  "c" (state),
		  "d" (smi_port), "S" (0), "D" (0)
	);

	pr_debug("result %x, low_freq %u, high_freq %u\n",
			result, low_mhz, high_mhz);

	/* abort if results are obviously incorrect... */
	if ((high_mhz + low_mhz) < 600)
		return -EINVAL;

	*high = high_mhz * 1000;
	*low  = low_mhz  * 1000;

	return result;
}

/**
 * speedstep_set_state - set the SpeedStep state
 * @state: new processor frequency state (SPEEDSTEP_LOW or SPEEDSTEP_HIGH)
 *
 */
static void speedstep_set_state(unsigned int state)
{
	unsigned int result = 0, command, new_state, dummy;
	unsigned long flags;
	unsigned int function = SET_SPEEDSTEP_STATE;
	unsigned int retry = 0;

	if (state > 0x1)
		return;

	/* Disable IRQs */
	preempt_disable();
	local_irq_save(flags);

	command = (smi_sig & 0xffffff00) | (smi_cmd & 0xff);

	pr_debug("trying to set frequency to state %u "
		"with command %x at port %x\n",
		state, command, smi_port);

	do {
		if (retry) {
			/*
			 * We need to enable interrupts, otherwise the blockage
			 * won't resolve.
			 *
			 * We disable preemption so that other processes don't
			 * run. If other processes were running, they could
			 * submit more DMA requests, making the blockage worse.
			 */
			pr_debug("retry %u, previous result %u, waiting...\n",
					retry, result);
			local_irq_enable();
			mdelay(retry * 50);
			local_irq_disable();
		}
		retry++;
		__asm__ __volatile__(
			"push %%ebp\n"
			"out %%al, (%%dx)\n"
			"pop %%ebp"
			: "=b" (new_state), "=D" (result),
			  "=c" (dummy), "=a" (dummy),
			  "=d" (dummy), "=S" (dummy)
			: "a" (command), "b" (function), "c" (state),
			  "d" (smi_port), "S" (0), "D" (0)
			);
	} while ((new_state != state) && (retry <= SMI_TRIES));

	/* enable IRQs */
	local_irq_restore(flags);
	preempt_enable();

	if (new_state == state)
		pr_debug("change to %u MHz succeeded after %u tries "
			"with result %u\n",
			(speedstep_freqs[new_state].frequency / 1000),
			retry, result);
	else
		pr_err("change to state %u failed with new_state %u and result %u\n",
		       state, new_state, result);

	return;
}


/**
 * speedstep_target - set a new CPUFreq policy
 * @policy: new policy
 * @index: index of new freq
 *
 * Sets a new CPUFreq policy/freq.
 */
static int speedstep_target(struct cpufreq_policy *policy, unsigned int index)
{
	speedstep_set_state(index);

	return 0;
}


static int speedstep_cpu_init(struct cpufreq_policy *policy)
{
	int result;
	unsigned int *low, *high;

	/* capability check */
	if (policy->cpu != 0)
		return -ENODEV;

	result = speedstep_smi_ownership();
	if (result) {
		pr_debug("fails in acquiring ownership of a SMI interface.\n");
		return -EINVAL;
	}

	/* detect low and high frequency */
	low = &speedstep_freqs[SPEEDSTEP_LOW].frequency;
	high = &speedstep_freqs[SPEEDSTEP_HIGH].frequency;

	result = speedstep_smi_get_freqs(low, high);
	if (result) {
		/* fall back to speedstep_lib.c dection mechanism:
		 * try both states out */
		pr_debug("could not detect low and high frequencies "
				"by SMI call.\n");
		result = speedstep_get_freqs(speedstep_processor,
				low, high,
				NULL,
				&speedstep_set_state);

		if (result) {
			pr_debug("could not detect two different speeds"
					" -- aborting.\n");
			return result;
		} else
			pr_debug("workaround worked.\n");
	}

	policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL;
	return cpufreq_table_validate_and_show(policy, speedstep_freqs);
}

static unsigned int speedstep_get(unsigned int cpu)
{
	if (cpu)
		return -ENODEV;
	return speedstep_get_frequency(speedstep_processor);
}


static int speedstep_resume(struct cpufreq_policy *policy)
{
	int result = speedstep_smi_ownership();

	if (result)
		pr_debug("fails in re-acquiring ownership of a SMI interface.\n");

	return result;
}

static struct cpufreq_driver speedstep_driver = {
	.name		= "speedstep-smi",
	.verify		= cpufreq_generic_frequency_table_verify,
	.target_index	= speedstep_target,
	.init		= speedstep_cpu_init,
	.get		= speedstep_get,
	.resume		= speedstep_resume,
	.attr		= cpufreq_generic_attr,
};

static const struct x86_cpu_id ss_smi_ids[] = {
	{ X86_VENDOR_INTEL, 6, 0xb, },
	{ X86_VENDOR_INTEL, 6, 0x8, },
	{ X86_VENDOR_INTEL, 15, 2 },
	{}
};
#if 0
/* Not auto loaded currently */
MODULE_DEVICE_TABLE(x86cpu, ss_smi_ids);
#endif

/**
 * speedstep_init - initializes the SpeedStep CPUFreq driver
 *
 *   Initializes the SpeedStep support. Returns -ENODEV on unsupported
 * BIOS, -EINVAL on problems during initiatization, and zero on
 * success.
 */
static int __init speedstep_init(void)
{
	if (!x86_match_cpu(ss_smi_ids))
		return -ENODEV;

	speedstep_processor = speedstep_detect_processor();

	switch (speedstep_processor) {
	case SPEEDSTEP_CPU_PIII_T:
	case SPEEDSTEP_CPU_PIII_C:
	case SPEEDSTEP_CPU_PIII_C_EARLY:
		break;
	default:
		speedstep_processor = 0;
	}

	if (!speedstep_processor) {
		pr_debug("No supported Intel CPU detected.\n");
		return -ENODEV;
	}

	pr_debug("signature:0x%.8x, command:0x%.8x, "
		"event:0x%.8x, perf_level:0x%.8x.\n",
		ist_info.signature, ist_info.command,
		ist_info.event, ist_info.perf_level);

	/* Error if no IST-SMI BIOS or no PARM
		 sig= 'ISGE' aka 'Intel Speedstep Gate E' */
	if ((ist_info.signature !=  0x47534943) && (
	    (smi_port == 0) || (smi_cmd == 0)))
		return -ENODEV;

	if (smi_sig == 1)
		smi_sig = 0x47534943;
	else
		smi_sig = ist_info.signature;

	/* setup smi_port from MODLULE_PARM or BIOS */
	if ((smi_port > 0xff) || (smi_port < 0))
		return -EINVAL;
	else if (smi_port == 0)
		smi_port = ist_info.command & 0xff;

	if ((smi_cmd > 0xff) || (smi_cmd < 0))
		return -EINVAL;
	else if (smi_cmd == 0)
		smi_cmd = (ist_info.command >> 16) & 0xff;

	return cpufreq_register_driver(&speedstep_driver);
}


/**
 * speedstep_exit - unregisters SpeedStep support
 *
 *   Unregisters SpeedStep support.
 */
static void __exit speedstep_exit(void)
{
	cpufreq_unregister_driver(&speedstep_driver);
}

module_param(smi_port, int, 0444);
module_param(smi_cmd,  int, 0444);
module_param(smi_sig, uint, 0444);

MODULE_PARM_DESC(smi_port, "Override the BIOS-given IST port with this value "
		"-- Intel's default setting is 0xb2");
MODULE_PARM_DESC(smi_cmd, "Override the BIOS-given IST command with this value "
		"-- Intel's default setting is 0x82");
MODULE_PARM_DESC(smi_sig, "Set to 1 to fake the IST signature when using the "
		"SMI interface.");

MODULE_AUTHOR("Hiroshi Miura");
MODULE_DESCRIPTION("Speedstep driver for IST applet SMI interface.");
MODULE_LICENSE("GPL");

module_init(speedstep_init);
module_exit(speedstep_exit);
Commit	Line	Data
1da177e4 LT	1	/*
	2	* Intel SpeedStep SMI driver.
	3	*
	4	* (C) 2003 Hiroshi Miura <miura@da-cha.org>
	5	*
	6	* Licensed under the terms of the GNU GPL License version 2.
	7	*
	8	*/
	9
	10
	11	/*********************************************************************
	12	* SPEEDSTEP - DEFINITIONS *
	13	*********************************************************************/
	14
1c5864e2 JP	15	#define pr_fmt(fmt) "cpufreq: " fmt
1c5864e2 JP	16
1da177e4	17	#include <linux/kernel.h>
32ee8c3e DJ	18	#include <linux/module.h>
32ee8c3e DJ	19	#include <linux/moduleparam.h>
1da177e4 LT	20	#include <linux/init.h>
1da177e4 LT	21	#include <linux/cpufreq.h>
1da177e4	22	#include <linux/delay.h>
bbfebd66	23	#include <linux/io.h>
1da177e4	24	#include <asm/ist.h>
fa8031ae	25	#include <asm/cpu_device_id.h>
1da177e4 LT	26
	27	#include "speedstep-lib.h"
	28
	29	/* speedstep system management interface port/command.
	30	*
	31	* These parameters are got from IST-SMI BIOS call.
	32	* If user gives it, these are used.
32ee8c3e	33	*
1da177e4	34	*/
bbfebd66 DJ	35	static int smi_port;
	36	static int smi_cmd;
	37	static unsigned int smi_sig;
1da177e4 LT	38
1da177e4 LT	39	/* info about the processor */
1cce76c2	40	static enum speedstep_processor speedstep_processor;
1da177e4	41
32ee8c3e DJ	42	/*
32ee8c3e DJ	43	* There are only two frequency states for each processor. Values
1da177e4 LT	44	* are in kHz for the time being.
	45	*/
	46	static struct cpufreq_frequency_table speedstep_freqs[] = {
7f4b0461 VK	47	{0, SPEEDSTEP_HIGH, 0},
	48	{0, SPEEDSTEP_LOW, 0},
	49	{0, 0, CPUFREQ_TABLE_END},
1da177e4 LT	50	};
	51
	52	#define GET_SPEEDSTEP_OWNER 0
	53	#define GET_SPEEDSTEP_STATE 1
	54	#define SET_SPEEDSTEP_STATE 2
	55	#define GET_SPEEDSTEP_FREQS 4
	56
	57	/* how often shall the SMI call be tried if it failed, e.g. because
	58	* of DMA activity going on? */
	59	#define SMI_TRIES 5
	60
1da177e4 LT	61	/**
	62	* speedstep_smi_ownership
	63	*/
bbfebd66	64	static int speedstep_smi_ownership(void)
1da177e4	65	{
c6e8256a	66	u32 command, result, magic, dummy;
1da177e4 LT	67	u32 function = GET_SPEEDSTEP_OWNER;
	68	unsigned char magic_data[] = "Copyright (c) 1999 Intel Corporation";
	69
	70	command = (smi_sig & 0xffffff00) \| (smi_cmd & 0xff);
	71	magic = virt_to_phys(magic_data);
	72
2d06d8c4	73	pr_debug("trying to obtain ownership with command %x at port %x\n",
bbfebd66	74	command, smi_port);
1da177e4 LT	75
1da177e4 LT	76	__asm__ __volatile__(
c6e8256a	77	"push %%ebp\n"
1da177e4	78	"out %%al, (%%dx)\n"
c6e8256a	79	"pop %%ebp\n"
bbfebd66 DJ	80	: "=D" (result),
	81	"=a" (dummy), "=b" (dummy), "=c" (dummy), "=d" (dummy),
	82	"=S" (dummy)
f081a529	83	: "a" (command), "b" (function), "c" (0), "d" (smi_port),
bbfebd66	84	"D" (0), "S" (magic)
f081a529	85	: "memory"
1da177e4 LT	86	);
1da177e4 LT	87
2d06d8c4	88	pr_debug("result is %x\n", result);
1da177e4 LT	89
	90	return result;
	91	}
	92
	93	/**
	94	* speedstep_smi_get_freqs - get SpeedStep preferred & current freq.
	95	* @low: the low frequency value is placed here
	96	* @high: the high frequency value is placed here
	97	*
	98	* Only available on later SpeedStep-enabled systems, returns false results or
	99	* even hangs [cf. bugme.osdl.org # 1422] on earlier systems. Empirical testing
	100	* shows that the latter occurs if !(ist_info.event & 0xFFFF).
	101	*/
bbfebd66	102	static int speedstep_smi_get_freqs(unsigned int low, unsigned int high)
1da177e4	103	{
c6e8256a	104	u32 command, result = 0, edi, high_mhz, low_mhz, dummy;
bbfebd66	105	u32 state = 0;
1da177e4 LT	106	u32 function = GET_SPEEDSTEP_FREQS;
	107
	108	if (!(ist_info.event & 0xFFFF)) {
2d06d8c4	109	pr_debug("bug #1422 -- can't read freqs from BIOS\n");
1da177e4 LT	110	return -ENODEV;
	111	}
	112
	113	command = (smi_sig & 0xffffff00) \| (smi_cmd & 0xff);
	114
2d06d8c4	115	pr_debug("trying to determine frequencies with command %x at port %x\n",
bbfebd66	116	command, smi_port);
1da177e4	117
c6e8256a SD	118	__asm__ __volatile__(
c6e8256a SD	119	"push %%ebp\n"
1da177e4	120	"out %%al, (%%dx)\n"
c6e8256a	121	"pop %%ebp"
bbfebd66 DJ	122	: "=a" (result),
	123	"=b" (high_mhz),
	124	"=c" (low_mhz),
	125	"=d" (state), "=D" (edi), "=S" (dummy)
	126	: "a" (command),
	127	"b" (function),
	128	"c" (state),
	129	"d" (smi_port), "S" (0), "D" (0)
1da177e4 LT	130	);
1da177e4 LT	131
2d06d8c4	132	pr_debug("result %x, low_freq %u, high_freq %u\n",
bbfebd66	133	result, low_mhz, high_mhz);
1da177e4 LT	134
	135	/* abort if results are obviously incorrect... */
	136	if ((high_mhz + low_mhz) < 600)
	137	return -EINVAL;
	138
	139	high = high_mhz 1000;
	140	low = low_mhz 1000;
	141
	142	return result;
32ee8c3e	143	}
1da177e4	144
1da177e4 LT	145	/**
	146	* speedstep_set_state - set the SpeedStep state
	147	* @state: new processor frequency state (SPEEDSTEP_LOW or SPEEDSTEP_HIGH)
	148	*
	149	*/
bbfebd66	150	static void speedstep_set_state(unsigned int state)
1da177e4	151	{
c6e8256a	152	unsigned int result = 0, command, new_state, dummy;
1da177e4	153	unsigned long flags;
bbfebd66	154	unsigned int function = SET_SPEEDSTEP_STATE;
1da177e4 LT	155	unsigned int retry = 0;
	156
	157	if (state > 0x1)
	158	return;
	159
	160	/* Disable IRQs */
d4d4eda2	161	preempt_disable();
1da177e4 LT	162	local_irq_save(flags);
	163
	164	command = (smi_sig & 0xffffff00) \| (smi_cmd & 0xff);
	165
2d06d8c4	166	pr_debug("trying to set frequency to state %u "
bbfebd66 DJ	167	"with command %x at port %x\n",
bbfebd66 DJ	168	state, command, smi_port);
1da177e4 LT	169
	170	do {
	171	if (retry) {
d4d4eda2 MP	172	/*
	173	* We need to enable interrupts, otherwise the blockage
	174	* won't resolve.
	175	*
	176	* We disable preemption so that other processes don't
	177	* run. If other processes were running, they could
	178	* submit more DMA requests, making the blockage worse.
	179	*/
2d06d8c4	180	pr_debug("retry %u, previous result %u, waiting...\n",
bbfebd66	181	retry, result);
d4d4eda2	182	local_irq_enable();
1da177e4	183	mdelay(retry * 50);
d4d4eda2	184	local_irq_disable();
1da177e4 LT	185	}
	186	retry++;
	187	__asm__ __volatile__(
c6e8256a	188	"push %%ebp\n"
1da177e4	189	"out %%al, (%%dx)\n"
c6e8256a	190	"pop %%ebp"
bbfebd66 DJ	191	: "=b" (new_state), "=D" (result),
	192	"=c" (dummy), "=a" (dummy),
	193	"=d" (dummy), "=S" (dummy)
	194	: "a" (command), "b" (function), "c" (state),
	195	"d" (smi_port), "S" (0), "D" (0)
1da177e4 LT	196	);
	197	} while ((new_state != state) && (retry <= SMI_TRIES));
	198
	199	/* enable IRQs */
	200	local_irq_restore(flags);
d4d4eda2	201	preempt_enable();
1da177e4	202
bbfebd66	203	if (new_state == state)
2d06d8c4	204	pr_debug("change to %u MHz succeeded after %u tries "
bbfebd66 DJ	205	"with result %u\n",
	206	(speedstep_freqs[new_state].frequency / 1000),
	207	retry, result);
	208	else
1c5864e2	209	pr_err("change to state %u failed with new_state %u and result %u\n",
b49c22a6	210	state, new_state, result);
1da177e4 LT	211
	212	return;
	213	}
	214
	215
	216	/**
	217	* speedstep_target - set a new CPUFreq policy
	218	* @policy: new policy
9c0ebcf7	219	* @index: index of new freq
1da177e4 LT	220	*
	221	* Sets a new CPUFreq policy/freq.
	222	*/
9c0ebcf7	223	static int speedstep_target(struct cpufreq_policy *policy, unsigned int index)
1da177e4	224	{
9c0ebcf7	225	speedstep_set_state(index);
1da177e4 LT	226
	227	return 0;
	228	}
	229
	230
1da177e4 LT	231	static int speedstep_cpu_init(struct cpufreq_policy *policy)
	232	{
	233	int result;
bbfebd66	234	unsigned int low, high;
1da177e4 LT	235
	236	/* capability check */
	237	if (policy->cpu != 0)
	238	return -ENODEV;
	239
	240	result = speedstep_smi_ownership();
	241	if (result) {
2d06d8c4	242	pr_debug("fails in acquiring ownership of a SMI interface.\n");
1da177e4 LT	243	return -EINVAL;
	244	}
	245
	246	/* detect low and high frequency */
bbfebd66 DJ	247	low = &speedstep_freqs[SPEEDSTEP_LOW].frequency;
	248	high = &speedstep_freqs[SPEEDSTEP_HIGH].frequency;
	249
	250	result = speedstep_smi_get_freqs(low, high);
1da177e4	251	if (result) {
bbfebd66 DJ	252	/* fall back to speedstep_lib.c dection mechanism:
bbfebd66 DJ	253	* try both states out */
2d06d8c4	254	pr_debug("could not detect low and high frequencies "
bbfebd66	255	"by SMI call.\n");
1da177e4	256	result = speedstep_get_freqs(speedstep_processor,
bbfebd66	257	low, high,
1a10760c	258	NULL,
1da177e4 LT	259	&speedstep_set_state);
	260
	261	if (result) {
2d06d8c4	262	pr_debug("could not detect two different speeds"
bbfebd66	263	" -- aborting.\n");
1da177e4 LT	264	return result;
1da177e4 LT	265	} else
2d06d8c4	266	pr_debug("workaround worked.\n");
1da177e4 LT	267	}
1da177e4 LT	268
1da177e4	269	policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL;
5f3a2d39	270	return cpufreq_table_validate_and_show(policy, speedstep_freqs);
1da177e4 LT	271	}
1da177e4 LT	272
1da177e4 LT	273	static unsigned int speedstep_get(unsigned int cpu)
	274	{
	275	if (cpu)
	276	return -ENODEV;
bbfebd66	277	return speedstep_get_frequency(speedstep_processor);
1da177e4 LT	278	}
	279
	280
	281	static int speedstep_resume(struct cpufreq_policy *policy)
	282	{
	283	int result = speedstep_smi_ownership();
	284
	285	if (result)
2d06d8c4	286	pr_debug("fails in re-acquiring ownership of a SMI interface.\n");
1da177e4 LT	287
	288	return result;
	289	}
	290
221dee28	291	static struct cpufreq_driver speedstep_driver = {
1da177e4	292	.name = "speedstep-smi",
3be1394a	293	.verify = cpufreq_generic_frequency_table_verify,
9c0ebcf7	294	.target_index = speedstep_target,
1da177e4	295	.init = speedstep_cpu_init,
1da177e4 LT	296	.get = speedstep_get,
1da177e4 LT	297	.resume = speedstep_resume,
3be1394a	298	.attr = cpufreq_generic_attr,
1da177e4 LT	299	};
1da177e4 LT	300
fa8031ae AK	301	static const struct x86_cpu_id ss_smi_ids[] = {
	302	{ X86_VENDOR_INTEL, 6, 0xb, },
	303	{ X86_VENDOR_INTEL, 6, 0x8, },
	304	{ X86_VENDOR_INTEL, 15, 2 },
	305	{}
	306	};
	307	#if 0
	308	/* Not auto loaded currently */
	309	MODULE_DEVICE_TABLE(x86cpu, ss_smi_ids);
	310	#endif
	311
1da177e4 LT	312	/**
	313	* speedstep_init - initializes the SpeedStep CPUFreq driver
	314	*
	315	* Initializes the SpeedStep support. Returns -ENODEV on unsupported
	316	* BIOS, -EINVAL on problems during initiatization, and zero on
	317	* success.
	318	*/
	319	static int __init speedstep_init(void)
	320	{
fa8031ae AK	321	if (!x86_match_cpu(ss_smi_ids))
	322	return -ENODEV;
	323
1da177e4 LT	324	speedstep_processor = speedstep_detect_processor();
	325
	326	switch (speedstep_processor) {
bbfebd66 DJ	327	case SPEEDSTEP_CPU_PIII_T:
	328	case SPEEDSTEP_CPU_PIII_C:
	329	case SPEEDSTEP_CPU_PIII_C_EARLY:
1da177e4 LT	330	break;
	331	default:
	332	speedstep_processor = 0;
	333	}
	334
	335	if (!speedstep_processor) {
2d06d8c4	336	pr_debug("No supported Intel CPU detected.\n");
1da177e4 LT	337	return -ENODEV;
	338	}
	339
a5f30eba HW	340	pr_debug("signature:0x%.8x, command:0x%.8x, "
a5f30eba HW	341	"event:0x%.8x, perf_level:0x%.8x.\n",
bbfebd66 DJ	342	ist_info.signature, ist_info.command,
bbfebd66 DJ	343	ist_info.event, ist_info.perf_level);
1da177e4	344
32ee8c3e	345	/* Error if no IST-SMI BIOS or no PARM
1da177e4	346	sig= 'ISGE' aka 'Intel Speedstep Gate E' */
32ee8c3e	347	if ((ist_info.signature != 0x47534943) && (
1da177e4 LT	348	(smi_port == 0) \|\| (smi_cmd == 0)))
	349	return -ENODEV;
	350
	351	if (smi_sig == 1)
	352	smi_sig = 0x47534943;
	353	else
	354	smi_sig = ist_info.signature;
	355
	356	/* setup smi_port from MODLULE_PARM or BIOS */
32ee8c3e	357	if ((smi_port > 0xff) \|\| (smi_port < 0))
1da177e4	358	return -EINVAL;
32ee8c3e	359	else if (smi_port == 0)
1da177e4	360	smi_port = ist_info.command & 0xff;
1da177e4	361
32ee8c3e	362	if ((smi_cmd > 0xff) \|\| (smi_cmd < 0))
1da177e4	363	return -EINVAL;
32ee8c3e	364	else if (smi_cmd == 0)
1da177e4	365	smi_cmd = (ist_info.command >> 16) & 0xff;
1da177e4 LT	366
	367	return cpufreq_register_driver(&speedstep_driver);
	368	}
	369
	370
	371	/**
	372	* speedstep_exit - unregisters SpeedStep support
	373	*
	374	* Unregisters SpeedStep support.
	375	*/
	376	static void __exit speedstep_exit(void)
	377	{
	378	cpufreq_unregister_driver(&speedstep_driver);
	379	}
	380
bbfebd66 DJ	381	module_param(smi_port, int, 0444);
	382	module_param(smi_cmd, int, 0444);
	383	module_param(smi_sig, uint, 0444);
1da177e4	384
bbfebd66 DJ	385	MODULE_PARM_DESC(smi_port, "Override the BIOS-given IST port with this value "
	386	"-- Intel's default setting is 0xb2");
	387	MODULE_PARM_DESC(smi_cmd, "Override the BIOS-given IST command with this value "
	388	"-- Intel's default setting is 0x82");
	389	MODULE_PARM_DESC(smi_sig, "Set to 1 to fake the IST signature when using the "
	390	"SMI interface.");
1da177e4	391
bbfebd66 DJ	392	MODULE_AUTHOR("Hiroshi Miura");
	393	MODULE_DESCRIPTION("Speedstep driver for IST applet SMI interface.");
	394	MODULE_LICENSE("GPL");
1da177e4 LT	395
	396	module_init(speedstep_init);
	397	module_exit(speedstep_exit);