processor.c

来自「Linux Kernel 2.6.9 for OMAP1710」· C语言 代码 · 共 2,497 行 · 第 1/5 页

/*
 * acpi_processor.c - ACPI Processor Driver ($Revision: 71 $)
 *
 *  Copyright (C) 2001, 2002 Andy Grover <[e-mail]>
 *  Copyright (C) 2001, 2002 Paul Diefenbaugh <[e-mail]>
 *  Copyright (C) 2004       Dominik Brodowski <[e-mail]>
 *
 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 *
 *  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 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 <linux/cpufreq.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>

#include <asm/io.h>
#include <asm/system.h>
#include <asm/delay.h>
#include <asm/uaccess.h>
#include <asm/processor.h>
#include <asm/smp.h>
#include <asm/acpi.h>

#include <acpi/acpi_bus.h>
#include <acpi/acpi_drivers.h>
#include <acpi/processor.h>


#define ACPI_PROCESSOR_COMPONENT	0x01000000
#define ACPI_PROCESSOR_CLASS		"processor"
#define ACPI_PROCESSOR_DRIVER_NAME	"ACPI Processor Driver"
#define ACPI_PROCESSOR_DEVICE_NAME	"Processor"
#define ACPI_PROCESSOR_FILE_INFO	"info"
#define ACPI_PROCESSOR_FILE_POWER	"power"
#define ACPI_PROCESSOR_FILE_THROTTLING	"throttling"
#define ACPI_PROCESSOR_FILE_LIMIT	"limit"
#define ACPI_PROCESSOR_FILE_PERFORMANCE	"performance"
#define ACPI_PROCESSOR_NOTIFY_PERFORMANCE 0x80
#define ACPI_PROCESSOR_NOTIFY_POWER	0x81

#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_LIMIT_USER	0
#define ACPI_PROCESSOR_LIMIT_THERMAL	1

#define _COMPONENT		ACPI_PROCESSOR_COMPONENT
ACPI_MODULE_NAME		("acpi_processor")

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


static int acpi_processor_add (struct acpi_device *device);
static int acpi_processor_remove (struct acpi_device *device, int type);
static int acpi_processor_info_open_fs(struct inode *inode, struct file *file);
static int acpi_processor_throttling_open_fs(struct inode *inode, struct file *file);
static int acpi_processor_power_open_fs(struct inode *inode, struct file *file);
static int acpi_processor_limit_open_fs(struct inode *inode, struct file *file);
static int acpi_processor_get_limit_info(struct acpi_processor *pr);

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,
			},
};


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

static struct file_operations acpi_processor_info_fops = {
	.open 		= acpi_processor_info_open_fs,
	.read		= seq_read,
	.llseek		= seq_lseek,
	.release	= single_release,
};

static struct file_operations acpi_processor_power_fops = {
	.open 		= acpi_processor_power_open_fs,
	.read		= seq_read,
	.llseek		= seq_lseek,
	.release	= single_release,
};

static struct file_operations acpi_processor_throttling_fops = {
	.open 		= acpi_processor_throttling_open_fs,
	.read		= seq_read,
	.llseek		= seq_lseek,
	.release	= single_release,
};

static struct file_operations acpi_processor_limit_fops = {
	.open 		= acpi_processor_limit_open_fs,
	.read		= seq_read,
	.llseek		= seq_lseek,
	.release	= single_release,
};

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.
	 */
	local_irq_disable();

	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) {
			local_irq_enable();
			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 */
		local_irq_enable();
		/* 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 */
		local_irq_enable();
		/* Compute time (ticks) that we were actually asleep */
		sleep_ticks = ticks_elapsed(t1, t2) - cx->latency_ticks - C3_OVERHEAD;
		break;

	default:
		local_irq_enable();
		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;
			}
		}
	}