drivers/acpi/processor.c

/*
 * acpi_processor.c - ACPI Processor Driver ($Revision: 69 $)
 *
 *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
 *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
 *
 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 *
 *  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.
 *
 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 *  TBD:
 *	1. Make # power/performance states dynamic.
 *	2. Support duty_cycle values that span bit 4.
 *	3. Optimize by having scheduler determine business instead of
 *	   having us try to calculate it here.
 *	4. Need C1 timing -- must modify kernel (IRQ handler) to get this.
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/types.h>
#include <linux/pci.h>
#include <linux/pm.h>
#include <asm/io.h>
#include <asm/system.h>
#include <asm/delay.h>
#include <linux/compatmac.h>
#include <linux/proc_fs.h>
#include <acpi/acpi_bus.h>
#include <acpi/acpi_drivers.h>


#define _COMPONENT		ACPI_PROCESSOR_COMPONENT
ACPI_MODULE_NAME		("acpi_processor")

MODULE_AUTHOR("Paul Diefenbaugh");
MODULE_DESCRIPTION(ACPI_PROCESSOR_DRIVER_NAME);
MODULE_LICENSE("GPL");

#define PREFIX				"ACPI: "

#define US_TO_PM_TIMER_TICKS(t)		((t * (PM_TIMER_FREQUENCY/1000)) / 1000)
#define C2_OVERHEAD			4	/* 1us (3.579 ticks per us) */
#define C3_OVERHEAD			4	/* 1us (3.579 ticks per us) */

#define ACPI_PROCESSOR_BUSY_METRIC	10

#define ACPI_PROCESSOR_MAX_POWER	ACPI_C_STATE_COUNT
#define ACPI_PROCESSOR_MAX_C2_LATENCY	100
#define ACPI_PROCESSOR_MAX_C3_LATENCY	1000

#define ACPI_PROCESSOR_MAX_PERFORMANCE	8

#define ACPI_PROCESSOR_MAX_THROTTLING	16
#define ACPI_PROCESSOR_MAX_THROTTLE	250	/* 25% */
#define ACPI_PROCESSOR_MAX_DUTY_WIDTH	4

#define ACPI_PROCESSOR_LIMIT_USER	0
#define ACPI_PROCESSOR_LIMIT_THERMAL	1

static int acpi_processor_add (struct acpi_device *device);
static int acpi_processor_remove (struct acpi_device *device, int type);

static struct acpi_driver acpi_processor_driver = {
	.name =		ACPI_PROCESSOR_DRIVER_NAME,
	.class =	ACPI_PROCESSOR_CLASS,
	.ids =		ACPI_PROCESSOR_HID,
	.ops =		{
				.add =		acpi_processor_add,
				.remove =	acpi_processor_remove,
			},
};

/* Power Management */

struct acpi_processor_cx_policy {
	u32			count;
	int			state;
	struct {
		u32			time;
		u32			ticks;
		u32			count;
		u32			bm;
	}			threshold;
};

struct acpi_processor_cx {
	u8			valid;
	u32			address;
	u32			latency;
	u32			latency_ticks;
	u32			power;
	u32			usage;
	struct acpi_processor_cx_policy promotion;
	struct acpi_processor_cx_policy demotion;
};

struct acpi_processor_power {
	int			state;
	int			default_state;
	u32			bm_activity;
	struct acpi_processor_cx states[ACPI_PROCESSOR_MAX_POWER];
};

/* Performance Management */

struct acpi_pct_register {
	u8			descriptor;
	u16			length;
	u8			space_id;
	u8			bit_width;
	u8			bit_offset;
	u8			reserved;
	u64			address;
} __attribute__ ((packed));

struct acpi_processor_px {
	acpi_integer		core_frequency;		/* megahertz */
	acpi_integer		power;			/* milliWatts */
	acpi_integer		transition_latency;	/* microseconds */
	acpi_integer		bus_master_latency;	/* microseconds */
	acpi_integer		control;		/* control value */
	acpi_integer		status;			/* success indicator */
};

struct acpi_processor_performance {
	int			state;
	int			platform_limit;
	u16			control_register;
	u16			status_register;
	u8			control_register_bit_width;
	u8			status_register_bit_width;
	int			state_count;
	struct acpi_processor_px states[ACPI_PROCESSOR_MAX_PERFORMANCE];
};


/* Throttling Control */

struct acpi_processor_tx {
	u16			power;
	u16			performance;
};

struct acpi_processor_throttling {
	int			state;
	u32			address;
	u8			duty_offset;
	u8			duty_width;
	int			state_count;
	struct acpi_processor_tx states[ACPI_PROCESSOR_MAX_THROTTLING];
};

/* Limit Interface */

struct acpi_processor_lx {
	int			px;		/* performace state */	
	int			tx;		/* throttle level */
};

struct acpi_processor_limit {
	struct acpi_processor_lx state;		/* current limit */
	struct acpi_processor_lx thermal;	/* thermal limit */
	struct acpi_processor_lx user;		/* user limit */
};


struct acpi_processor_flags {
	u8			power:1;
	u8			performance:1;
	u8			throttling:1;
	u8			limit:1;
	u8			bm_control:1;
	u8			bm_check:1;
	u8			reserved:2;
};

struct acpi_processor {
	acpi_handle		handle;
	u32			acpi_id;
	u32			id;
	struct acpi_processor_flags flags;
	struct acpi_processor_power power;
	struct acpi_processor_performance performance;
	struct acpi_processor_throttling throttling;
	struct acpi_processor_limit limit;
};

struct acpi_processor_errata {
	u8			smp;
	struct {
		u8			throttle:1;
		u8			fdma:1;
		u8			reserved:6;
		u32			bmisx;
	}			piix4;
};

static struct acpi_processor	*processors[NR_CPUS];
static struct acpi_processor_errata errata;
static void (*pm_idle_save)(void);


/* --------------------------------------------------------------------------
                                Errata Handling
   -------------------------------------------------------------------------- */

int
acpi_processor_errata_piix4 (
	struct pci_dev		*dev)
{
	u8			rev = 0;
	u8			value1 = 0;
	u8			value2 = 0;

	ACPI_FUNCTION_TRACE("acpi_processor_errata_piix4");

	if (!dev)
		return_VALUE(-EINVAL);

	/*
	 * Note that 'dev' references the PIIX4 ACPI Controller.
	 */

	pci_read_config_byte(dev, PCI_REVISION_ID, &rev);

	switch (rev) {
	case 0:
		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found PIIX4 A-step\n"));
		break;
	case 1:
		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found PIIX4 B-step\n"));
		break;
	case 2:
		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found PIIX4E\n"));
		break;
	case 3:
		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found PIIX4M\n"));
		break;
	default:
		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found unknown PIIX4\n"));
		break;
	}

	switch (rev) {

	case 0:		/* PIIX4 A-step */
	case 1:		/* PIIX4 B-step */
		/*
		 * See specification changes #13 ("Manual Throttle Duty Cycle")
		 * and #14 ("Enabling and Disabling Manual Throttle"), plus
		 * erratum #5 ("STPCLK# Deassertion Time") from the January 
		 * 2002 PIIX4 specification update.  Applies to only older 
		 * PIIX4 models.
		 */
		errata.piix4.throttle = 1;

	case 2:		/* PIIX4E */
	case 3:		/* PIIX4M */
		/*
		 * See erratum #18 ("C3 Power State/BMIDE and Type-F DMA 
		 * Livelock") from the January 2002 PIIX4 specification update.
		 * Applies to all PIIX4 models.
		 */

		/* 
		 * BM-IDE
		 * ------
		 * Find the PIIX4 IDE Controller and get the Bus Master IDE 
		 * Status register address.  We'll use this later to read 
		 * each IDE controller's DMA status to make sure we catch all
		 * DMA activity.
		 */
		dev = pci_find_subsys(PCI_VENDOR_ID_INTEL,
		           PCI_DEVICE_ID_INTEL_82371AB, 
                           PCI_ANY_ID, PCI_ANY_ID, NULL);
		if (dev)
			errata.piix4.bmisx = pci_resource_start(dev, 4);

		/* 
		 * Type-F DMA
		 * ----------
		 * Find the PIIX4 ISA Controller and read the Motherboard
		 * DMA controller's status to see if Type-F (Fast) DMA mode
		 * is enabled (bit 7) on either channel.  Note that we'll 
		 * disable C3 support if this is enabled, as some legacy 
		 * devices won't operate well if fast DMA is disabled.
		 */
		dev = pci_find_subsys(PCI_VENDOR_ID_INTEL, 
			PCI_DEVICE_ID_INTEL_82371AB_0, 
			PCI_ANY_ID, PCI_ANY_ID, NULL);
		if (dev) {
			pci_read_config_byte(dev, 0x76, &value1);
			pci_read_config_byte(dev, 0x77, &value2);
			if ((value1 & 0x80) || (value2 & 0x80))
				errata.piix4.fdma = 1;
		}

		break;
	}

	if (errata.piix4.bmisx)
		ACPI_DEBUG_PRINT((ACPI_DB_INFO, 
			"Bus master activity detection (BM-IDE) erratum enabled\n"));
	if (errata.piix4.fdma)
		ACPI_DEBUG_PRINT((ACPI_DB_INFO, 
			"Type-F DMA livelock erratum (C3 disabled)\n"));

	return_VALUE(0);
}


int
acpi_processor_errata (
	struct acpi_processor	*pr)
{
	int			result = 0;
	struct pci_dev		*dev = NULL;

	ACPI_FUNCTION_TRACE("acpi_processor_errata");

	if (!pr)
		return_VALUE(-EINVAL);

	/*
	 * PIIX4
	 */
	dev = pci_find_subsys(PCI_VENDOR_ID_INTEL, 
		PCI_DEVICE_ID_INTEL_82371AB_3, PCI_ANY_ID, PCI_ANY_ID, NULL);
	if (dev)
		result = acpi_processor_errata_piix4(dev);

	return_VALUE(result);
}


/* --------------------------------------------------------------------------
                                Power Management
   -------------------------------------------------------------------------- */

static inline u32
ticks_elapsed (
	u32			t1,
	u32			t2)
{
	if (t2 >= t1)
		return (t2 - t1);
	else if (!acpi_fadt.tmr_val_ext)
		return (((0x00FFFFFF - t1) + t2) & 0x00FFFFFF);
	else
		return ((0xFFFFFFFF - t1) + t2);
}


static void
acpi_processor_power_activate (
	struct acpi_processor	*pr,
	int			state)
{
	if (!pr)
		return;

	pr->power.states[pr->power.state].promotion.count = 0;
	pr->power.states[pr->power.state].demotion.count = 0;

	/* Cleanup from old state. */
	switch (pr->power.state) {
	case ACPI_STATE_C3:
		/* Disable bus master reload */
		acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD, 0, ACPI_MTX_DO_NOT_LOCK);
		break;
	}

	/* Prepare to use new state. */
	switch (state) {
	case ACPI_STATE_C3:
		/* Enable bus master reload */
		acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD, 1, ACPI_MTX_DO_NOT_LOCK);
		break;
	}

	pr->power.state = state;

	return;
}


static void
acpi_processor_idle (void)
{
	struct acpi_processor	*pr = NULL;
	struct acpi_processor_cx *cx = NULL;
	int			next_state = 0;
	int			sleep_ticks = 0;
	u32			t1, t2 = 0;

	pr = processors[smp_processor_id()];
	if (!pr)
		return;

	/*
	 * Interrupts must be disabled during bus mastering calculations and
	 * for C2/C3 transitions.
	 */
	__cli();

	cx = &(pr->power.states[pr->power.state]);

	/*
	 * Check BM Activity
	 * -----------------
	 * Check for bus mastering activity (if required), record, and check
	 * for demotion.
	 */
	if (pr->flags.bm_check) {
		u32		bm_status = 0;

		pr->power.bm_activity <<= 1;

		acpi_get_register(ACPI_BITREG_BUS_MASTER_STATUS, 
			&bm_status, ACPI_MTX_DO_NOT_LOCK);
		if (bm_status) {
			pr->power.bm_activity++;
			acpi_set_register(ACPI_BITREG_BUS_MASTER_STATUS,
				1, ACPI_MTX_DO_NOT_LOCK);
		}
		/*
		 * PIIX4 Erratum #18: Note that BM_STS doesn't always reflect
		 * the true state of bus mastering activity; forcing us to 
		 * manually check the BMIDEA bit of each IDE channel.
		 */
		else if (errata.piix4.bmisx) {
			if ((inb_p(errata.piix4.bmisx + 0x02) & 0x01) 
				|| (inb_p(errata.piix4.bmisx + 0x0A) & 0x01))
				pr->power.bm_activity++;
		}
		/*
		 * Apply bus mastering demotion policy.  Automatically demote
		 * to avoid a faulty transition.  Note that the processor 
		 * won't enter a low-power state during this call (to this 
		 * funciton) but should upon the next.
		 *
		 * TBD: A better policy might be to fallback to the demotion 
		 *      state (use it for this quantum only) istead of 
		 *      demoting -- and rely on duration as our sole demotion
		 *      qualification.  This may, however, introduce DMA 
		 *      issues (e.g. floppy DMA transfer overrun/underrun).
		 */
		if (pr->power.bm_activity & cx->demotion.threshold.bm) {
			__sti();
			next_state = cx->demotion.state;
			goto end;
		}
	}

	cx->usage++;

	/*
	 * Sleep:
	 * ------
	 * Invoke the current Cx state to put the processor to sleep.
	 */
	switch (pr->power.state) {

	case ACPI_STATE_C1:
		/* Invoke C1. */
		safe_halt();
		/*
                 * TBD: Can't get time duration while in C1, as resumes
		 *      go to an ISR rather than here.  Need to instrument
		 *      base interrupt handler.
		 */
		sleep_ticks = 0xFFFFFFFF;
		break;

	case ACPI_STATE_C2:
		/* Get start time (ticks) */
		t1 = inl(acpi_fadt.xpm_tmr_blk.address);
		/* Invoke C2 */
		inb(pr->power.states[ACPI_STATE_C2].address);
		/* Dummy op - must do something useless after P_LVL2 read */
		t2 = inl(acpi_fadt.xpm_tmr_blk.address);
		/* Get end time (ticks) */
		t2 = inl(acpi_fadt.xpm_tmr_blk.address);
		/* Re-enable interrupts */
		__sti();
		/* Compute time (ticks) that we were actually asleep */
		sleep_ticks = ticks_elapsed(t1, t2) - cx->latency_ticks - C2_OVERHEAD;
		break;

	case ACPI_STATE_C3:
		/* Disable bus master arbitration */
		acpi_set_register(ACPI_BITREG_ARB_DISABLE, 1, ACPI_MTX_DO_NOT_LOCK);
		/* Get start time (ticks) */
		t1 = inl(acpi_fadt.xpm_tmr_blk.address);
		/* Invoke C3 */
		inb(pr->power.states[ACPI_STATE_C3].address);
		/* Dummy op - must do something useless after P_LVL3 read */
		t2 = inl(acpi_fadt.xpm_tmr_blk.address);
		/* Get end time (ticks) */
		t2 = inl(acpi_fadt.xpm_tmr_blk.address);
		/* Enable bus master arbitration */
		acpi_set_register(ACPI_BITREG_ARB_DISABLE, 0, ACPI_MTX_DO_NOT_LOCK);
		/* Re-enable interrupts */
		__sti();
		/* Compute time (ticks) that we were actually asleep */
		sleep_ticks = ticks_elapsed(t1, t2) - cx->latency_ticks - C3_OVERHEAD;
		break;

	default:
		__sti();
		return;
	}

	next_state = pr->power.state;

	/*
	 * Promotion?
	 * ----------
	 * Track the number of longs (time asleep is greater than threshold)
	 * and promote when the count threshold is reached.  Note that bus
	 * mastering activity may prevent promotions.
	 */
	if (cx->promotion.state) {
		if (sleep_ticks > cx->promotion.threshold.ticks) {
			cx->promotion.count++;
 			cx->demotion.count = 0;
			if (cx->promotion.count >= cx->promotion.threshold.count) {
				if (pr->flags.bm_check) {
					if (!(pr->power.bm_activity & cx->promotion.threshold.bm)) {
						next_state = cx->promotion.state;
						goto end;
					}
				}
				else {
					next_state = cx->promotion.state;
					goto end;
				}
			}
		}
	}

	/*
	 * Demotion?
	 * ---------
	 * Track the number of shorts (time asleep is less than time threshold)
	 * and demote when the usage threshold is reached.
	 */
	if (cx->demotion.state) {
		if (sleep_ticks < cx->demotion.threshold.ticks) {
			cx->demotion.count++;
			cx->promotion.count = 0;
			if (cx->demotion.count >= cx->demotion.threshold.count) {
				next_state = cx->demotion.state;
				goto end;
			}
		}
	}

end:
	/*
	 * New Cx State?
	 * -------------
	 * If we're going to start using a new Cx state we must clean up
	 * from the previous and prepare to use the new.
	 */
	if (next_state != pr->power.state)
		acpi_processor_power_activate(pr, next_state);

	return;
}


static int
acpi_processor_set_power_policy (
	struct acpi_processor	*pr)
{
	ACPI_FUNCTION_TRACE("acpi_processor_set_power_policy");

	/*
	 * This function sets the default Cx state policy (OS idle handler).
	 * Our scheme is to promote quickly to C2 but more conservatively
	 * to C3.  We're favoring C2  for its characteristics of low latency
	 * (quick response), good power savings, and ability to allow bus
	 * mastering activity.  Note that the Cx state policy is completely
	 * customizable and can be altered dynamically.
	 */

	if (!pr)
		return_VALUE(-EINVAL);

	/*
	 * C0/C1
	 * -----
	 */
	pr->power.state = ACPI_STATE_C1;
	pr->power.default_state = ACPI_STATE_C1;

	/*
	 * C1/C2
	 * -----
	 * Set the default C1 promotion and C2 demotion policies, where we
	 * promote from C1 to C2 after several (10) successive C1 transitions,
	 * as we cannot (currently) measure the time spent in C1. Demote from
	 * C2 to C1 anytime we experience a 'short' (time spent in C2 is less
	 * than the C2 transtion latency).  Note the simplifying assumption 
	 * that the 'cost' of a transition is amortized when we sleep for at
	 * least as long as the transition's latency (thus the total transition
	 * time is two times the latency).
	 *
	 * TBD: Measure C1 sleep times by instrumenting the core IRQ handler.
	 * TBD: Demote to default C-State after long periods of activity.
	 * TBD: Investigate policy's use of CPU utilization -vs- sleep duration.
	 */
	if (pr->power.states[ACPI_STATE_C2].valid) {
		pr->power.states[ACPI_STATE_C1].promotion.threshold.count = 10;
		pr->power.states[ACPI_STATE_C1].promotion.threshold.ticks =
			pr->power.states[ACPI_STATE_C2].latency_ticks;
		pr->power.states[ACPI_STATE_C1].promotion.state = ACPI_STATE_C2;

		pr->power.states[ACPI_STATE_C2].demotion.threshold.count = 1;
		pr->power.states[ACPI_STATE_C2].demotion.threshold.ticks =
			pr->power.states[ACPI_STATE_C2].latency_ticks;
		pr->power.states[ACPI_STATE_C2].demotion.state = ACPI_STATE_C1;
	}

	/*
	 * C2/C3
	 * -----
	 * Set default C2 promotion and C3 demotion policies, where we promote
	 * from C2 to C3 after several (4) cycles of no bus mastering activity
	 * while maintaining sleep time criteria.  Demote immediately on a
	 * short or whenever bus mastering activity occurs.
	 */
	if ((pr->power.states[ACPI_STATE_C2].valid) &&
		(pr->power.states[ACPI_STATE_C3].valid)) {
		pr->power.states[ACPI_STATE_C2].promotion.threshold.count = 4;
		pr->power.states[ACPI_STATE_C2].promotion.threshold.ticks =
			pr->power.states[ACPI_STATE_C3].latency_ticks;
		pr->power.states[ACPI_STATE_C2].promotion.threshold.bm = 0x0F;
		pr->power.states[ACPI_STATE_C2].promotion.state = ACPI_STATE_C3;

		pr->power.states[ACPI_STATE_C3].demotion.threshold.count = 1;
		pr->power.states[ACPI_STATE_C3].demotion.threshold.ticks =
			pr->power.states[ACPI_STATE_C3].latency_ticks;
		pr->power.states[ACPI_STATE_C3].demotion.threshold.bm = 0x0F;
		pr->power.states[ACPI_STATE_C3].demotion.state = ACPI_STATE_C2;
	}

	return_VALUE(0);
}


int
acpi_processor_get_power_info (
	struct acpi_processor	*pr)
{
	int			result = 0;

	ACPI_FUNCTION_TRACE("acpi_processor_get_power_info");

	if (!pr)
		return_VALUE(-EINVAL);

	ACPI_DEBUG_PRINT((ACPI_DB_INFO,
		"lvl2[0x%08x] lvl3[0x%08x]\n",
		pr->power.states[ACPI_STATE_C2].address,
		pr->power.states[ACPI_STATE_C3].address));

	/* TBD: Support ACPI 2.0 objects */

	/*
	 * C0
	 * --
	 * This state exists only as filler in our array.
	 */
	pr->power.states[ACPI_STATE_C0].valid = 1;

	/*
	 * C1
	 * --
	 * ACPI requires C1 support for all processors.
	 *
	 * TBD: What about PROC_C1?
	 */
	pr->power.states[ACPI_STATE_C1].valid = 1;

	/*
	 * C2
	 * --
	 * We're (currently) only supporting C2 on UP systems.
	 *
	 * TBD: Support for C2 on MP (P_LVL2_UP).
	 */
	if (pr->power.states[ACPI_STATE_C2].address) {

		pr->power.states[ACPI_STATE_C2].latency = acpi_fadt.plvl2_lat;

		/*
		 * C2 latency must be less than or equal to 100 microseconds.
		 */
		if (acpi_fadt.plvl2_lat > ACPI_PROCESSOR_MAX_C2_LATENCY)
			ACPI_DEBUG_PRINT((ACPI_DB_INFO,
				"C2 latency too large [%d]\n",
				acpi_fadt.plvl2_lat));
		/*
		 * Only support C2 on UP systems (see TBD above).
		 */
		else if (errata.smp)
			ACPI_DEBUG_PRINT((ACPI_DB_INFO,
				"C2 not supported in SMP mode\n"));
		/*
		 * Otherwise we've met all of our C2 requirements.
		 * Normalize the C2 latency to expidite policy.
		 */
		else {
			pr->power.states[ACPI_STATE_C2].valid = 1;
			pr->power.states[ACPI_STATE_C2].latency_ticks = 
				US_TO_PM_TIMER_TICKS(acpi_fadt.plvl2_lat);
		}
	}

	/*
	 * C3
	 * --
	 * TBD: Investigate use of WBINVD on UP/SMP system in absence of
	 *	bm_control.
	 */
	if (pr->power.states[ACPI_STATE_C3].address) {

		pr->power.states[ACPI_STATE_C3].latency = acpi_fadt.plvl3_lat;

		/*
		 * C3 latency must be less than or equal to 1000 microseconds.
		 */
		if (acpi_fadt.plvl3_lat > ACPI_PROCESSOR_MAX_C3_LATENCY)
			ACPI_DEBUG_PRINT((ACPI_DB_INFO,
				"C3 latency too large [%d]\n", 
				acpi_fadt.plvl3_lat));
		/*
		 * Only support C3 when bus mastering arbitration control
		 * is present (able to disable bus mastering to maintain
		 * cache coherency while in C3).
		 */
		else if (!pr->flags.bm_control)
			ACPI_DEBUG_PRINT((ACPI_DB_INFO,
				"C3 support requires bus mastering control\n"));
		/*
		 * Only support C3 on UP systems, as bm_control is only viable
		 * on a UP system and flushing caches (e.g. WBINVD) is simply 
		 * too costly (at this time).
		 */
		else if (errata.smp)
			ACPI_DEBUG_PRINT((ACPI_DB_INFO,
				"C3 not supported in SMP mode\n"));
		/*
		 * PIIX4 Erratum #18: We don't support C3 when Type-F (fast) 
		 * DMA transfers are used by any ISA device to avoid livelock.
		 * Note that we could disable Type-F DMA (as recommended by
		 * the erratum), but this is known to disrupt certain ISA 
		 * devices thus we take the conservative approach.
		 */
		else if (errata.piix4.fdma) {
			ACPI_DEBUG_PRINT((ACPI_DB_INFO,
				"C3 not supported on PIIX4 with Type-F DMA\n"));
		}
		/*
		 * Otherwise we've met all of our C3 requirements.  
		 * Normalize the C2 latency to expidite policy.  Enable
		 * checking of bus mastering status (bm_check) so we can 
		 * use this in our C3 policy.
		 */
		else {
			pr->power.states[ACPI_STATE_C3].valid = 1;
			pr->power.states[ACPI_STATE_C3].latency_ticks = 
				US_TO_PM_TIMER_TICKS(acpi_fadt.plvl3_lat);
			pr->flags.bm_check = 1;
		}
	}

	/*
	 * Set Default Policy
	 * ------------------
	 * Now that we know which state are supported, set the default
	 * policy.  Note that this policy can be changed dynamically
	 * (e.g. encourage deeper sleeps to conserve battery life when
	 * not on AC).
	 */
	result = acpi_processor_set_power_policy(pr);
	if (result)
		return_VALUE(result);

	/*
	 * If this processor supports C2 or C3 we denote it as being 'power
	 * manageable'.  Note that there's really no policy involved for
	 * when only C1 is supported.
	 */
	if (pr->power.states[ACPI_STATE_C2].valid 
		|| pr->power.states[ACPI_STATE_C3].valid)
		pr->flags.power = 1;

	return_VALUE(0);
}


/* --------------------------------------------------------------------------
                              Performance Management
   -------------------------------------------------------------------------- */

static int 
acpi_processor_get_platform_limit (
	struct acpi_processor*	pr)
{
	acpi_status		status = 0;
	unsigned long		ppc = 0;

	ACPI_FUNCTION_TRACE("acpi_processor_get_platform_limit");

	if (!pr)
		return_VALUE(-EINVAL);

	/*
	 * _PPC indicates the maximum state currently supported by the platform
	 * (e.g. 0 = states 0..n; 1 = states 1..n; etc.
	 */
	status = acpi_evaluate_integer(pr->handle, "_PPC", NULL, &ppc);
	if(ACPI_FAILURE(status)) {
		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error evaluating _PPC\n"));
		return_VALUE(-ENODEV);
	}

	pr->performance.platform_limit = (int) ppc;

	return_VALUE(0);
}


static int 
acpi_processor_get_performance_control (
	struct acpi_processor	*pr)
{
	int			result = 0;
	acpi_status		status = 0;
	struct acpi_buffer	buffer = {ACPI_ALLOCATE_BUFFER, NULL};
	union acpi_object	*pct = NULL;
	union acpi_object	obj = {0};
	struct acpi_pct_register *reg = NULL;

	ACPI_FUNCTION_TRACE("acpi_processor_get_performance_control");

	status = acpi_evaluate_object(pr->handle, "_PCT", NULL, &buffer);
	if(ACPI_FAILURE(status)) {
		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error evaluating _PCT\n"));
		return_VALUE(-ENODEV);
	}

	pct = (union acpi_object *) buffer.pointer;
	if (!pct || (pct->type != ACPI_TYPE_PACKAGE) 
		|| (pct->package.count != 2)) {
		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid _PCT data\n"));
		result = -EFAULT;
		goto end;
	}

	/*
	 * control_register
	 */

	obj = pct->package.elements[0];

	if ((obj.type != ACPI_TYPE_BUFFER) 
		|| (obj.buffer.length < sizeof(struct acpi_pct_register)) 
		|| (obj.buffer.pointer == NULL)) {
		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, 
			"Invalid _PCT data (control_register)\n"));
		result = -EFAULT;
		goto end;
	}

	reg = (struct acpi_pct_register *) (obj.buffer.pointer);

	if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO) {
		ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
			"Unsupported address space [%d] (control_register)\n",
			(u32) reg->space_id));
		result = -EFAULT;
		goto end;
	}

	pr->performance.control_register = (u16) reg->address;
	pr->performance.control_register_bit_width = reg->bit_width;
	/*
	 * status_register
	 */

	obj = pct->package.elements[1];

	if ((obj.type != ACPI_TYPE_BUFFER) 
		|| (obj.buffer.length < sizeof(struct acpi_pct_register)) 
		|| (obj.buffer.pointer == NULL)) {
		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, 
			"Invalid _PCT data (status_register)\n"));
		result = -EFAULT;
		goto end;
	}

	reg = (struct acpi_pct_register *) (obj.buffer.pointer);

	if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO) {
		ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
			"Unsupported address space [%d] (status_register)\n",
			(u32) reg->space_id));
		result = -EFAULT;
		goto end;
	}

	pr->performance.status_register = (u16) reg->address;
	pr->performance.status_register_bit_width = reg->bit_width;

	ACPI_DEBUG_PRINT((ACPI_DB_INFO, 
		"control_register[0x%04x] status_register[0x%04x]\n",
		pr->performance.control_register,
		pr->performance.status_register));

end:
	acpi_os_free(buffer.pointer);

	return_VALUE(result);
}


static int 
acpi_processor_get_performance_states (
	struct acpi_processor*	pr)
{
	int			result = 0;
	acpi_status		status = AE_OK;
	struct acpi_buffer	buffer = {ACPI_ALLOCATE_BUFFER, NULL};
	struct acpi_buffer	format = {sizeof("NNNNNN"), "NNNNNN"};
	struct acpi_buffer	state = {0, NULL};
	union acpi_object 	*pss = NULL;
	int			i = 0;

	ACPI_FUNCTION_TRACE("acpi_processor_get_performance_states");

	status = acpi_evaluate_object(pr->handle, "_PSS", NULL, &buffer);
	if(ACPI_FAILURE(status)) {
		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error evaluating _PSS\n"));
		return_VALUE(-ENODEV);
	}

	pss = (union acpi_object *) buffer.pointer;
	if (!pss || (pss->type != ACPI_TYPE_PACKAGE)) {
		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid _PSS data\n"));
		result = -EFAULT;
		goto end;
	}

	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d performance states\n", 
		pss->package.count));

	if (pss->package.count > ACPI_PROCESSOR_MAX_PERFORMANCE) {
		pr->performance.state_count = ACPI_PROCESSOR_MAX_PERFORMANCE;
		ACPI_DEBUG_PRINT((ACPI_DB_INFO, 
			"Limiting number of states to max (%d)\n", 
			ACPI_PROCESSOR_MAX_PERFORMANCE));
	}
	else
		pr->performance.state_count = pss->package.count;

	if (pr->performance.state_count > 1)
		pr->flags.performance = 1;

	for (i = 0; i < pr->performance.state_count; i++) {

		struct acpi_processor_px *px = &(pr->performance.states[i]);

		state.length = sizeof(struct acpi_processor_px);
		state.pointer = px;

		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Extracting state %d\n", i));

		status = acpi_extract_package(&(pss->package.elements[i]), 
			&format, &state);
		if (ACPI_FAILURE(status)) {
			ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid _PSS data\n"));
			result = -EFAULT;
			goto end;
		}

		ACPI_DEBUG_PRINT((ACPI_DB_INFO, 
			"State [%d]: core_frequency[%d] power[%d] transition_latency[%d] bus_master_latency[%d] control[0x%x] status[0x%x]\n",
			i, 
			(u32) px->core_frequency, 
			(u32) px->power, 
			(u32) px->transition_latency, 
			(u32) px->bus_master_latency,
			(u32) px->control, 
			(u32) px->status));
	}

end:
	acpi_os_free(buffer.pointer);

	return_VALUE(result);
}

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 acpi_processor	*pr,
	int			state)
{
	u16			port = 0;
	u8			bit_width = 0;
	int			ret = 0;
	u32			value = 0;
	int			i = 0;

	ACPI_FUNCTION_TRACE("acpi_processor_set_performance");

	if (!pr)
		return_VALUE(-EINVAL);

	if (!pr->flags.performance)
		return_VALUE(-ENODEV);

	if (state >= pr->performance.state_count) {
		ACPI_DEBUG_PRINT((ACPI_DB_WARN, 
			"Invalid target state (P%d)\n", state));
		return_VALUE(-ENODEV);
	}

	if (state < pr->performance.platform_limit) {
		ACPI_DEBUG_PRINT((ACPI_DB_WARN, 
			"Platform limit (P%d) overrides target state (P%d)\n",
			pr->performance.platform_limit, state));
		return_VALUE(-ENODEV);
	}

	if (state == pr->performance.state) {
		ACPI_DEBUG_PRINT((ACPI_DB_INFO, 
			"Already at target state (P%d)\n", state));
		return_VALUE(0);
	}

	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Transitioning from P%d to P%d\n",
		pr->performance.state, state));

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

	port = pr->performance.control_register;
	value = (u32) pr->performance.states[state].control;
	bit_width = pr->performance.control_register_bit_width;

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

	ret = acpi_processor_write_port(port, bit_width, value);
	if (ret) {
		ACPI_DEBUG_PRINT((ACPI_DB_WARN,
			"Invalid port width 0x%04x\n", bit_width));
		return_VALUE(ret);
	}

	/*
	 * 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 = pr->performance.status_register;
	bit_width = pr->performance.status_register_bit_width;

	ACPI_DEBUG_PRINT((ACPI_DB_INFO, 
		"Looking for 0x%08x from port 0x%04x\n",
		(u32) pr->performance.states[state].status, port));

	for (i=0; i<100; i++) {
		ret = acpi_processor_read_port(port, bit_width, &value);
		if (ret) {	
			ACPI_DEBUG_PRINT((ACPI_DB_WARN,
				"Invalid port width 0x%04x\n", bit_width));
			return_VALUE(ret);
		}
		if (value == (u32) pr->performance.states[state].status)
			break;
		udelay(10);
	}

	if (value != (u32) pr->performance.states[state].status) {
		ACPI_DEBUG_PRINT((ACPI_DB_WARN, "Transition failed\n"));
		return_VALUE(-ENODEV);
	}

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

	pr->performance.state = state;

	return_VALUE(0);
}


static int
acpi_processor_get_performance_info (
	struct acpi_processor	*pr)
{
	int			result = 0;
	acpi_status		status = AE_OK;
	acpi_handle		handle = NULL;

	ACPI_FUNCTION_TRACE("acpi_processor_get_performance_info");

	if (!pr)
		return_VALUE(-EINVAL);

	status = acpi_get_handle(pr->handle, "_PCT", &handle);
	if (ACPI_FAILURE(status)) {
		ACPI_DEBUG_PRINT((ACPI_DB_INFO, 
			"ACPI-based processor performance control unavailable\n"));
		return_VALUE(0);
	}

	result = acpi_processor_get_performance_control(pr);
	if (result)
		return_VALUE(result);

	result = acpi_processor_get_performance_states(pr);
	if (result)
		return_VALUE(result);

	result = acpi_processor_get_platform_limit(pr);
	if (result)
		return_VALUE(result);

	/* 
	 * TBD: Don't trust the latency values we get from BIOS, but rather
	 *      measure the latencies during run-time (e.g. get_latencies).
	 */

	return_VALUE(0);
}


/* --------------------------------------------------------------------------
                              Throttling Control
   -------------------------------------------------------------------------- */

static int
acpi_processor_get_throttling (
	struct acpi_processor	*pr)
{
	int			state = 0;
	u32			value = 0;
	u32			duty_mask = 0;
	u32			duty_value = 0;

	ACPI_FUNCTION_TRACE("acpi_processor_get_throttling");

	if (!pr)
		return_VALUE(-EINVAL);

	if (!pr->flags.throttling)
		return_VALUE(-ENODEV);

	pr->throttling.state = 0;

	__cli();

	duty_mask = pr->throttling.state_count - 1;

	duty_mask <<= pr->throttling.duty_offset;

	value = inl(pr->throttling.address);

	/*
	 * Compute the current throttling state when throttling is enabled
	 * (bit 4 is on).
	 */
	if (value & 0x10) {
		duty_value = value & duty_mask;
		duty_value >>= pr->throttling.duty_offset;

		if (duty_value)
			state = pr->throttling.state_count-duty_value;
	}

	pr->throttling.state = state;

	__sti();

	ACPI_DEBUG_PRINT((ACPI_DB_INFO, 
		"Throttling state is T%d (%d%% throttling applied)\n",
		state, pr->throttling.states[state].performance));

	return_VALUE(0);
}


static int
acpi_processor_set_throttling (
	struct acpi_processor	*pr,
	int			state)
{
	u32                     value = 0;
	u32                     duty_mask = 0;
	u32                     duty_value = 0;

	ACPI_FUNCTION_TRACE("acpi_processor_set_throttling");

	if (!pr)
		return_VALUE(-EINVAL);

	if ((state < 0) || (state > (pr->throttling.state_count - 1)))
		return_VALUE(-EINVAL);

	if (!pr->flags.throttling)
		return_VALUE(-ENODEV);

	if (state == pr->throttling.state)
		return_VALUE(0);

	__cli();

	/*
	 * Calculate the duty_value and duty_mask.
	 */
	if (state) {
		duty_value = pr->throttling.state_count - state;

		duty_value <<= pr->throttling.duty_offset;

		/* Used to clear all duty_value bits */
		duty_mask = pr->throttling.state_count - 1;

		duty_mask <<= acpi_fadt.duty_offset;
		duty_mask = ~duty_mask;
	}

	/*
	 * Disable throttling by writing a 0 to bit 4.  Note that we must
	 * turn it off before you can change the duty_value.
	 */
	value = inl(pr->throttling.address);
	if (value & 0x10) {
		value &= 0xFFFFFFEF;
		outl(value, pr->throttling.address);
	}

	/*
	 * Write the new duty_value and then enable throttling.  Note
	 * that a state value of 0 leaves throttling disabled.
	 */
	if (state) {
		value &= duty_mask;
		value |= duty_value;
		outl(value, pr->throttling.address);

		value |= 0x00000010;
		outl(value, pr->throttling.address);
	}

	pr->throttling.state = state;

	__sti();

	ACPI_DEBUG_PRINT((ACPI_DB_INFO, 
		"Throttling state set to T%d (%d%%)\n", state, 
		(pr->throttling.states[state].performance?pr->throttling.states[state].performance/10:0)));

	return_VALUE(0);
}


static int
acpi_processor_get_throttling_info (
	struct acpi_processor	*pr)
{
	int			result = 0;
	int			step = 0;
	int			i = 0;

	ACPI_FUNCTION_TRACE("acpi_processor_get_throttling_info");

	ACPI_DEBUG_PRINT((ACPI_DB_INFO,
		"pblk_address[0x%08x] duty_offset[%d] duty_width[%d]\n",
		pr->throttling.address,
		pr->throttling.duty_offset,
		pr->throttling.duty_width));

	if (!pr)
		return_VALUE(-EINVAL);

	/* TBD: Support ACPI 2.0 objects */

	if (!pr->throttling.address) {
		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No throttling register\n"));
		return_VALUE(0);
	}
	else if (!pr->throttling.duty_width) {
		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No throttling states\n"));
		return_VALUE(0);
	}
	/* TBD: Support duty_cycle values that span bit 4. */
	else if ((pr->throttling.duty_offset
		+ pr->throttling.duty_width) > 4) {
		ACPI_DEBUG_PRINT((ACPI_DB_WARN, "duty_cycle spans bit 4\n"));
		return_VALUE(0);
	}

	/*
	 * PIIX4 Errata: We don't support throttling on the original PIIX4.
	 * This shouldn't be an issue as few (if any) mobile systems ever
	 * used this part.
	 */
	if (errata.piix4.throttle) {
		ACPI_DEBUG_PRINT((ACPI_DB_INFO, 
			"Throttling not supported on PIIX4 A- or B-step\n"));
		return_VALUE(0);
	}

	pr->throttling.state_count = 1 << acpi_fadt.duty_width;

	/*
	 * Compute state values. Note that throttling displays a linear power/
	 * performance relationship (at 50% performance the CPU will consume
	 * 50% power).  Values are in 1/10th of a percent to preserve accuracy.
	 */

	step = (1000 / pr->throttling.state_count);

	for (i=0; i<pr->throttling.state_count; i++) {
		pr->throttling.states[i].performance = step * i;
		pr->throttling.states[i].power = step * i;
	}

	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d throttling states\n", 
		pr->throttling.state_count));

	pr->flags.throttling = 1;

	/*
	 * Disable throttling (if enabled).  We'll let subsequent policy (e.g. 
	 * thermal) decide to lower performance if it so chooses, but for now 
	 * we'll crank up the speed.
	 */

	result = acpi_processor_get_throttling(pr);
	if (result)
		goto end;

	if (pr->throttling.state) {
		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Disabling throttling (was T%d)\n", 
			pr->throttling.state));
		result = acpi_processor_set_throttling(pr, 0);
		if (result)
			goto end;
	}

end:
	if (result)
		pr->flags.throttling = 0;

	return_VALUE(result);
}


/* --------------------------------------------------------------------------
                                 Limit Interface
   -------------------------------------------------------------------------- */

static int
acpi_processor_apply_limit (
	struct acpi_processor* 	pr)
{
	int			result = 0;
	u16			px = 0;
	u16			tx = 0;

	ACPI_FUNCTION_TRACE("acpi_processor_apply_limit");

	if (!pr)
		return_VALUE(-EINVAL);

	if (!pr->flags.limit)
		return_VALUE(-ENODEV);

	if (pr->flags.performance) {
		px = pr->performance.platform_limit;
		if (pr->limit.user.px > px)
			px = pr->limit.user.px;
		if (pr->limit.thermal.px > px)
			px = pr->limit.thermal.px;

		result = acpi_processor_set_performance(pr, px);
		if (result)
			goto end;
	}

	if (pr->flags.throttling) {
		if (pr->limit.user.tx > tx)
			tx = pr->limit.user.tx;
		if (pr->limit.thermal.tx > tx)
			tx = pr->limit.thermal.tx;

		result = acpi_processor_set_throttling(pr, tx);
		if (result)
			goto end;
	}

	pr->limit.state.px = px;
	pr->limit.state.tx = tx;

	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Processor [%d] limit set to (P%d:T%d)\n",
		pr->id,
		pr->limit.state.px,
		pr->limit.state.tx));

end:
	if (result)
		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Unable to set limit\n"));

	return_VALUE(result);
}


int
acpi_processor_set_thermal_limit (
	acpi_handle		handle,
	int			type)
{
	int			result = 0;
	struct acpi_processor	*pr = NULL;
	struct acpi_device	*device = NULL;
	int			px = 0;
	int			tx = 0;

	ACPI_FUNCTION_TRACE("acpi_processor_set_thermal_limit");

	if ((type < ACPI_PROCESSOR_LIMIT_NONE) 
		|| (type > ACPI_PROCESSOR_LIMIT_DECREMENT))
		return_VALUE(-EINVAL);

	result = acpi_bus_get_device(handle, &device);
	if (result)
		return_VALUE(result);

	pr = (struct acpi_processor *) acpi_driver_data(device);
	if (!pr)
		return_VALUE(-ENODEV);

	if (!pr->flags.limit)
		return_VALUE(-ENODEV);

	/* Thermal limits are always relative to the current Px/Tx state. */
	if (pr->flags.performance)
		pr->limit.thermal.px = pr->performance.state;
	if (pr->flags.throttling)
		pr->limit.thermal.tx = pr->throttling.state;

	/*
	 * Our default policy is to only use throttling at the lowest
	 * performance state.
	 */

	px = pr->limit.thermal.px;
	tx = pr->limit.thermal.tx;

	switch (type) {

	case ACPI_PROCESSOR_LIMIT_NONE:
		px = 0;
		tx = 0;
		break;

	case ACPI_PROCESSOR_LIMIT_INCREMENT:
		if (pr->flags.performance) {
			if (px == (pr->performance.state_count - 1))
				ACPI_DEBUG_PRINT((ACPI_DB_INFO, 
					"At maximum performance state\n"));
			else {
				px++;
				goto end;
			}
		}
		if (pr->flags.throttling) {
			if (tx == (pr->throttling.state_count - 1))
				ACPI_DEBUG_PRINT((ACPI_DB_INFO, 
					"At maximum throttling state\n"));
			else
				tx++;
		}
		break;

	case ACPI_PROCESSOR_LIMIT_DECREMENT:
		if (pr->flags.performance) {
			if (px == pr->performance.platform_limit)
				ACPI_DEBUG_PRINT((ACPI_DB_INFO, 
					"At minimum performance state\n"));
			else  {
				px--;
				goto end;
			}
		}
		if (pr->flags.throttling) {
			if (tx == 0)
				ACPI_DEBUG_PRINT((ACPI_DB_INFO, 
					"At minimum throttling state\n"));
			else
				tx--;
		}
		break;
	}

end:
	pr->limit.thermal.px = px;
	pr->limit.thermal.tx = tx;

	result = acpi_processor_apply_limit(pr);
	if (result)
		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, 
			"Unable to set thermal limit\n"));

	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Thermal limit now (P%d:T%d)\n",
		pr->limit.thermal.px,
		pr->limit.thermal.tx));

	return_VALUE(result);
}


static int
acpi_processor_get_limit_info (
	struct acpi_processor	*pr)
{
	ACPI_FUNCTION_TRACE("acpi_processor_get_limit_info");

	if (!pr)
		return_VALUE(-EINVAL);

	if (pr->flags.performance || pr->flags.throttling)
		pr->flags.limit = 1;

	return_VALUE(0);
}


/* --------------------------------------------------------------------------
                              FS Interface (/proc)
   -------------------------------------------------------------------------- */

struct proc_dir_entry		*acpi_processor_dir = NULL;

static int
acpi_processor_read_info (
	char			*page,
	char			**start,
	off_t			off,
	int 			count,
	int 			*eof,
	void			*data)
{
	struct acpi_processor	*pr = (struct acpi_processor *) data;
	char			*p = page;
	int			len = 0;

	ACPI_FUNCTION_TRACE("acpi_processor_read_info");

	if (!pr || (off != 0))
		goto end;

	p += sprintf(p, "processor id:            %d\n",
		pr->id);

	p += sprintf(p, "acpi id:                 %d\n",
		pr->acpi_id);

	p += sprintf(p, "bus mastering control:   %s\n",
		pr->flags.bm_control ? "yes" : "no");

	p += sprintf(p, "power management:        %s\n",
		pr->flags.power ? "yes" : "no");

	p += sprintf(p, "throttling control:      %s\n",
		pr->flags.throttling ? "yes" : "no");

	p += sprintf(p, "performance management:  %s\n",
		pr->flags.performance ? "yes" : "no");

	p += sprintf(p, "limit interface:         %s\n",
		pr->flags.limit ? "yes" : "no");

end:
	len = (p - page);
	if (len <= off+count) *eof = 1;
	*start = page + off;
	len -= off;
	if (len>count) len = count;
	if (len<0) len = 0;

	return_VALUE(len);
}


static int
acpi_processor_read_power (
	char			*page,
	char			**start,
	off_t			off,
	int 			count,
	int 			*eof,
	void			*data)
{
	struct acpi_processor	*pr = (struct acpi_processor *) data;
	char			*p = page;
	int			len = 0;
	int			i = 0;

	ACPI_FUNCTION_TRACE("acpi_processor_read_power");

	if (!pr || (off != 0))
		goto end;

	p += sprintf(p, "active state:            C%d\n",
		pr->power.state);

	p += sprintf(p, "default state:           C%d\n",
		pr->power.default_state);

	p += sprintf(p, "bus master activity:     %08x\n",
		pr->power.bm_activity);

	p += sprintf(p, "states:\n");

	for (i=1; i<ACPI_C_STATE_COUNT; i++) {

		p += sprintf(p, "   %cC%d:                  ", 
			(i == pr->power.state?'*':' '), i);

		if (!pr->power.states[i].valid) {
			p += sprintf(p, "<not supported>\n");
			continue;
		}

		if (pr->power.states[i].promotion.state)
			p += sprintf(p, "promotion[C%d] ",
				pr->power.states[i].promotion.state);
		else
			p += sprintf(p, "promotion[--] ");

		if (pr->power.states[i].demotion.state)
			p += sprintf(p, "demotion[C%d] ",
				pr->power.states[i].demotion.state);
		else
			p += sprintf(p, "demotion[--] ");

		p += sprintf(p, "latency[%03d] usage[%08d]\n",
			pr->power.states[i].latency,
			pr->power.states[i].usage);
	}

end:
	len = (p - page);
	if (len <= off+count) *eof = 1;
	*start = page + off;
	len -= off;
	if (len>count) len = count;
	if (len<0) len = 0;

	return_VALUE(len);
}


static int
acpi_processor_read_performance (
	char			*page,
	char			**start,
	off_t			off,
	int 			count,
	int 			*eof,
	void			*data)
{
	struct acpi_processor	*pr = (struct acpi_processor *) data;
	char			*p = page;
	int			len = 0;
	int			i = 0;

	ACPI_FUNCTION_TRACE("acpi_processor_read_performance");

	if (!pr || (off != 0))
		goto end;

	if (!pr->flags.performance) {
		p += sprintf(p, "<not supported>\n");
		goto end;
	}

	p += sprintf(p, "state count:             %d\n",
		pr->performance.state_count);

	p += sprintf(p, "active state:            P%d\n",
		pr->performance.state);

	p += sprintf(p, "states:\n");

	for (i=0; i<pr->performance.state_count; i++)
		p += sprintf(p, "   %cP%d:                  %d MHz, %d mW, %d uS\n",
			(i == pr->performance.state?'*':' '), i,
			(u32) pr->performance.states[i].core_frequency,
			(u32) pr->performance.states[i].power,
			(u32) pr->performance.states[i].transition_latency);

end:
	len = (p - page);
	if (len <= off+count) *eof = 1;
	*start = page + off;
	len -= off;
	if (len>count) len = count;
	if (len<0) len = 0;

	return_VALUE(len);
}


static int
acpi_processor_write_performance (
        struct file		*file,
        const char		*buffer,
        unsigned long		count,
        void			*data)
{
	int			result = 0;
	struct acpi_processor	*pr = (struct acpi_processor *) data;
	char			state_string[12] = {'\0'};

	ACPI_FUNCTION_TRACE("acpi_processor_write_performance");

	if (!pr || (count > sizeof(state_string) - 1))
		return_VALUE(-EINVAL);
	
	if (copy_from_user(state_string, buffer, count))
		return_VALUE(-EFAULT);
	
	state_string[count] = '\0';

	result = acpi_processor_set_performance(pr, 
		simple_strtoul(state_string, NULL, 0));
	if (result)
		return_VALUE(result);

	return_VALUE(count);
}


static int
acpi_processor_read_throttling (
	char			*page,
	char			**start,
	off_t			off,
	int 			count,
	int 			*eof,
	void			*data)
{
	struct acpi_processor	*pr = (struct acpi_processor *) data;
	char			*p = page;
	int			len = 0;
	int			i = 0;
	int                     result = 0;

	ACPI_FUNCTION_TRACE("acpi_processor_read_throttling");

	if (!pr || (off != 0))
		goto end;

	if (!(pr->throttling.state_count > 0)) {
		p += sprintf(p, "<not supported>\n");
		goto end;
	}

	result = acpi_processor_get_throttling(pr);

	if (result) {
		p += sprintf(p, "Could not determine current throttling state.\n");
		goto end;
	}

	p += sprintf(p, "state count:             %d\n",
		pr->throttling.state_count);

	p += sprintf(p, "active state:            T%d\n",
		pr->throttling.state);

	p += sprintf(p, "states:\n");

	for (i=0; i<pr->throttling.state_count; i++)
		p += sprintf(p, "   %cT%d:                  %02d%%\n",
			(i == pr->throttling.state?'*':' '), i,
			(pr->throttling.states[i].performance?pr->throttling.states[i].performance/10:0));

end:
	len = (p - page);
	if (len <= off+count) *eof = 1;
	*start = page + off;
	len -= off;
	if (len>count) len = count;
	if (len<0) len = 0;

	return_VALUE(len);
}


static int
acpi_processor_write_throttling (
        struct file		*file,
        const char		*buffer,
        unsigned long		count,
        void			*data)
{
	int			result = 0;
	struct acpi_processor	*pr = (struct acpi_processor *) data;
	char			state_string[12] = {'\0'};

	ACPI_FUNCTION_TRACE("acpi_processor_write_throttling");

	if (!pr || (count > sizeof(state_string) - 1))
		return_VALUE(-EINVAL);
	
	if (copy_from_user(state_string, buffer, count))
		return_VALUE(-EFAULT);
	
	state_string[count] = '\0';
	
	result = acpi_processor_set_throttling(pr, 
		simple_strtoul(state_string, NULL, 0));
	if (result)
		return_VALUE(result);

	return_VALUE(count);
}


static int
acpi_processor_read_limit (
	char			*page,
	char			**start,
	off_t			off,
	int 			count,
	int 			*eof,
	void			*data)
{
	struct acpi_processor	*pr = (struct acpi_processor *) data;
	char			*p = page;
	int			len = 0;

	ACPI_FUNCTION_TRACE("acpi_processor_read_limit");

	if (!pr || (off != 0))
		goto end;

	if (!pr->flags.limit) {
		p += sprintf(p, "<not supported>\n");
		goto end;
	}

	p += sprintf(p, "active limit:            P%d:T%d\n",
		pr->limit.state.px, pr->limit.state.tx);

	p += sprintf(p, "platform limit:          P%d:T0\n",
		pr->flags.performance?pr->performance.platform_limit:0);

	p += sprintf(p, "user limit:              P%d:T%d\n",
		pr->limit.user.px, pr->limit.user.tx);

	p += sprintf(p, "thermal limit:           P%d:T%d\n",
		pr->limit.thermal.px, pr->limit.thermal.tx);

end:
	len = (p - page);
	if (len <= off+count) *eof = 1;
	*start = page + off;
	len -= off;
	if (len>count) len = count;
	if (len<0) len = 0;

	return_VALUE(len);
}


static int
acpi_processor_write_limit (
        struct file		*file,
        const char		*buffer,
        unsigned long		count,
        void			*data)
{
	int			result = 0;
	struct acpi_processor	*pr = (struct acpi_processor *) data;
	char			limit_string[25] = {'\0'};
	int			px = 0;
	int			tx = 0;

	ACPI_FUNCTION_TRACE("acpi_processor_write_limit");

	if (!pr || (count > sizeof(limit_string) - 1)) {
		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid argument\n"));
		return_VALUE(-EINVAL);
	}
	
	if (copy_from_user(limit_string, buffer, count)) {
		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid data\n"));
		return_VALUE(-EFAULT);
	}
	
	limit_string[count] = '\0';

	if (sscanf(limit_string, "%d:%d", &px, &tx) != 2) {
		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid data format\n"));
		return_VALUE(-EINVAL);
	}

	if (pr->flags.performance) {
		if ((px < pr->performance.platform_limit) 
			|| (px > (pr->performance.state_count - 1))) {
			ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid px\n"));
			return_VALUE(-EINVAL);
		}
		pr->limit.user.px = px;
	}

	if (pr->flags.throttling) {
		if ((tx < 0) || (tx > (pr->throttling.state_count - 1))) {
			ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid tx\n"));
			return_VALUE(-EINVAL);
		}
		pr->limit.user.tx = tx;
	}

	result = acpi_processor_apply_limit(pr);

	return_VALUE(count);
}


static int
acpi_processor_add_fs (
	struct acpi_device	*device)
{
	struct proc_dir_entry	*entry = NULL;

	ACPI_FUNCTION_TRACE("acpi_processor_add_fs");

	if (!acpi_device_dir(device)) {
		acpi_device_dir(device) = proc_mkdir(acpi_device_bid(device),
			acpi_processor_dir);
		if (!acpi_device_dir(device))
			return_VALUE(-ENODEV);
	}
	acpi_device_dir(device)->owner = THIS_MODULE;

	/* 'info' [R] */
	entry = create_proc_entry(ACPI_PROCESSOR_FILE_INFO,
		S_IRUGO, acpi_device_dir(device));
	if (!entry)
		ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
			"Unable to create '%s' fs entry\n",
			ACPI_PROCESSOR_FILE_INFO));
	else {
		entry->read_proc = acpi_processor_read_info;
		entry->data = acpi_driver_data(device);
		entry->owner = THIS_MODULE;
	}

	/* 'power' [R] */
	entry = create_proc_entry(ACPI_PROCESSOR_FILE_POWER,
		S_IRUGO, acpi_device_dir(device));
	if (!entry)
		ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
			"Unable to create '%s' fs entry\n",
			ACPI_PROCESSOR_FILE_POWER));
	else {
		entry->read_proc = acpi_processor_read_power;
		entry->data = acpi_driver_data(device);
		entry->owner = THIS_MODULE;
	}

	/* 'performance' [R/W] */
	entry = create_proc_entry(ACPI_PROCESSOR_FILE_PERFORMANCE,
		S_IFREG|S_IRUGO|S_IWUSR, acpi_device_dir(device));
	if (!entry)
		ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
			"Unable to create '%s' fs entry\n",
			ACPI_PROCESSOR_FILE_PERFORMANCE));
	else {
		entry->read_proc = acpi_processor_read_performance;
		entry->write_proc = acpi_processor_write_performance;
		entry->data = acpi_driver_data(device);
		entry->owner = THIS_MODULE;
	}

	/* 'throttling' [R/W] */
	entry = create_proc_entry(ACPI_PROCESSOR_FILE_THROTTLING,
		S_IFREG|S_IRUGO|S_IWUSR, acpi_device_dir(device));
	if (!entry)
		ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
			"Unable to create '%s' fs entry\n",
			ACPI_PROCESSOR_FILE_THROTTLING));
	else {
		entry->read_proc = acpi_processor_read_throttling;
		entry->write_proc = acpi_processor_write_throttling;
		entry->data = acpi_driver_data(device);
		entry->owner = THIS_MODULE;
	}

	/* 'limit' [R/W] */
	entry = create_proc_entry(ACPI_PROCESSOR_FILE_LIMIT,
		S_IFREG|S_IRUGO|S_IWUSR, acpi_device_dir(device));
	if (!entry)
		ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
			"Unable to create '%s' fs entry\n",
			ACPI_PROCESSOR_FILE_LIMIT));
	else {
		entry->read_proc = acpi_processor_read_limit;
		entry->write_proc = acpi_processor_write_limit;
		entry->data = acpi_driver_data(device);
		entry->owner = THIS_MODULE;
	}

	return_VALUE(0);
}


static int
acpi_processor_remove_fs (
	struct acpi_device	*device)
{
	ACPI_FUNCTION_TRACE("acpi_processor_remove_fs");

	if (acpi_device_dir(device)) {
		remove_proc_entry(acpi_device_bid(device), acpi_processor_dir);
		acpi_device_dir(device) = NULL;
	}

	return_VALUE(0);
}


/* --------------------------------------------------------------------------
                                 Driver Interface
   -------------------------------------------------------------------------- */

static int
acpi_processor_get_info (
	struct acpi_processor	*pr)
{
	acpi_status		status = 0;
	union acpi_object	object = {0};
	struct acpi_buffer	buffer = {sizeof(union acpi_object), &object};
	static int		cpu_index = 0;

	ACPI_FUNCTION_TRACE("acpi_processor_get_info");

	if (!pr)
		return_VALUE(-EINVAL);

#ifdef CONFIG_SMP
	if (smp_num_cpus > 1)
		errata.smp = smp_num_cpus;

	/*
	 *  Extra Processor objects may be enumerated on MP systems with
	 *  less than the max # of CPUs. They should be ignored.
	 */
	if ((cpu_index + 1) > smp_num_cpus)
		return_VALUE(-ENODEV);
#endif

	acpi_processor_errata(pr);

	/*
	 * Check to see if we have bus mastering arbitration control.  This
	 * is required for proper C3 usage (to maintain cache coherency).
	 */
	if (acpi_fadt.V1_pm2_cnt_blk && acpi_fadt.pm2_cnt_len) {
		pr->flags.bm_control = 1;
		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
			"Bus mastering arbitration control present\n"));
	}
	else
		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
			"No bus mastering arbitration control\n"));

	/*
	 * Evalute the processor object.  Note that it is common on SMP to
	 * have the first (boot) processor with a valid PBLK address while
	 * all others have a NULL address.
	 */
	status = acpi_evaluate_object(pr->handle, NULL, NULL, &buffer);
	if (ACPI_FAILURE(status)) {
		ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
			"Error evaluating processor object\n"));
		return_VALUE(-ENODEV);
	}

	/*
	 * TBD: Synch processor ID (via LAPIC/LSAPIC structures) on SMP.
	 *	>>> 'acpi_get_processor_id(acpi_id, &id)' in arch/xxx/acpi.c
	 */
	pr->id = cpu_index++;
	pr->acpi_id = object.processor.proc_id;

	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Processor [%d:%d]\n", pr->id, 
		pr->acpi_id));

	if (!object.processor.pblk_address)
		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No PBLK (NULL address)\n"));
	else if (object.processor.pblk_length != 6)
		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid PBLK length [%d]\n",
			object.processor.pblk_length));
	else {
		pr->throttling.address = object.processor.pblk_address;
		pr->throttling.duty_offset = acpi_fadt.duty_offset;
		pr->throttling.duty_width = acpi_fadt.duty_width;
		pr->power.states[ACPI_STATE_C2].address =
			object.processor.pblk_address + 4;
		pr->power.states[ACPI_STATE_C3].address =
			object.processor.pblk_address + 5;
	}

	acpi_processor_get_power_info(pr);
	acpi_processor_get_performance_info(pr);
	acpi_processor_get_throttling_info(pr);
	acpi_processor_get_limit_info(pr);

	return_VALUE(0);
}


static void
acpi_processor_notify (
	acpi_handle		handle,
	u32			event,
	void			*data)
{
	int			result = 0;
	struct acpi_processor	*pr = (struct acpi_processor *) data;
	struct acpi_device	*device = NULL;

	ACPI_FUNCTION_TRACE("acpi_processor_notify");

	if (!pr)
		return_VOID;

	if (acpi_bus_get_device(pr->handle, &device))
		return_VOID;

	switch (event) {
	case ACPI_PROCESSOR_NOTIFY_PERFORMANCE:
		result = acpi_processor_get_platform_limit(pr);
		if (!result)
			acpi_processor_apply_limit(pr);

		acpi_bus_generate_event(device, event, 
			pr->performance.platform_limit);
		break;
	case ACPI_PROCESSOR_NOTIFY_POWER:
		/* TBD */
		acpi_bus_generate_event(device, event, 0);
		break;
	default:
		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
			"Unsupported event [0x%x]\n", event));
		break;
	}

	return_VOID;
}


static int
acpi_processor_add (
	struct acpi_device	*device)
{
	int			result = 0;
	acpi_status		status = AE_OK;
	struct acpi_processor	*pr = NULL;
	u32			i = 0;

	ACPI_FUNCTION_TRACE("acpi_processor_add");

	if (!device)
		return_VALUE(-EINVAL);

	pr = kmalloc(sizeof(struct acpi_processor), GFP_KERNEL);
	if (!pr)
		return_VALUE(-ENOMEM);
	memset(pr, 0, sizeof(struct acpi_processor));

	pr->handle = device->handle;
	sprintf(acpi_device_name(device), "%s", ACPI_PROCESSOR_DEVICE_NAME);
	sprintf(acpi_device_class(device), "%s", ACPI_PROCESSOR_CLASS);
	acpi_driver_data(device) = pr;

	result = acpi_processor_get_info(pr);
	if (result)
		goto end;

	result = acpi_processor_add_fs(device);
	if (result)
		goto end;

	status = acpi_install_notify_handler(pr->handle, ACPI_DEVICE_NOTIFY, 
		acpi_processor_notify, pr);
	if (ACPI_FAILURE(status)) {
		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, 
			"Error installing notify handler\n"));
		result = -ENODEV;
		goto end;
	}

	processors[pr->id] = pr;

	/*
	 * Install the idle handler if processor power management is supported.
	 * Note that the default idle handler (default_idle) will be used on 
	 * platforms that only support C1.
	 */
	if ((pr->id == 0) && (pr->flags.power)) {
		pm_idle_save = pm_idle;
		pm_idle = acpi_processor_idle;
	}
	
	printk(KERN_INFO PREFIX "%s [%s] (supports",
		acpi_device_name(device), acpi_device_bid(device));
	for (i=1; i<ACPI_C_STATE_COUNT; i++)
		if (pr->power.states[i].valid)
			printk(" C%d", i);
	if (pr->flags.performance)
		printk(", %d performance states", pr->performance.state_count);
	if (pr->flags.throttling)
		printk(", %d throttling states", pr->throttling.state_count);
	printk(")\n");

end:
	if (result) {
		acpi_processor_remove_fs(device);
		kfree(pr);
	}

	return_VALUE(result);
}


static int
acpi_processor_remove (
	struct acpi_device	*device,
	int			type)
{
	acpi_status		status = AE_OK;
	struct acpi_processor	*pr = NULL;

	ACPI_FUNCTION_TRACE("acpi_processor_remove");

	if (!device || !acpi_driver_data(device))
		return_VALUE(-EINVAL);

	pr = (struct acpi_processor *) acpi_driver_data(device);

	/* Unregister the idle handler when processor #0 is removed. */
	if (pr->id == 0)
		pm_idle = pm_idle_save;

	status = acpi_remove_notify_handler(pr->handle, ACPI_DEVICE_NOTIFY, 
		acpi_processor_notify);
	if (ACPI_FAILURE(status)) {
		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, 
			"Error removing notify handler\n"));
	}

	acpi_processor_remove_fs(device);

	processors[pr->id] = NULL;

	kfree(pr);

	return_VALUE(0);
}


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

	ACPI_FUNCTION_TRACE("acpi_processor_init");

	memset(&processors, 0, sizeof(processors));
	memset(&errata, 0, sizeof(errata));

	acpi_processor_dir = proc_mkdir(ACPI_PROCESSOR_CLASS, acpi_root_dir);
	if (!acpi_processor_dir)
		return_VALUE(-ENODEV);
	acpi_processor_dir->owner = THIS_MODULE;

	result = acpi_bus_register_driver(&acpi_processor_driver);
	if (result < 0) {
		remove_proc_entry(ACPI_PROCESSOR_CLASS, acpi_root_dir);
		return_VALUE(-ENODEV);
	}

	return_VALUE(0);
}


static void __exit
acpi_processor_exit (void)
{
	ACPI_FUNCTION_TRACE("acpi_processor_exit");

	acpi_bus_unregister_driver(&acpi_processor_driver);

	remove_proc_entry(ACPI_PROCESSOR_CLASS, acpi_root_dir);

	return_VOID;
}


module_init(acpi_processor_init);
module_exit(acpi_processor_exit);

EXPORT_SYMBOL(acpi_processor_set_thermal_limit);