processor_core.c

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/*
 * 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]>
 *  Copyright (C) 2004  Anil S Keshavamurthy <[e-mail]>
 *  			- Added processor hotplug support
 *
 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 *
 *  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/cpu.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/dmi.h>
#include <linux/moduleparam.h>
#include <linux/cpuidle.h>

#include <asm/io.h>
#include <asm/system.h>
#include <asm/cpu.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_DEVICE_NAME	"Processor"
#define ACPI_PROCESSOR_FILE_INFO	"info"
#define ACPI_PROCESSOR_FILE_THROTTLING	"throttling"
#define ACPI_PROCESSOR_FILE_LIMIT	"limit"
#define ACPI_PROCESSOR_NOTIFY_PERFORMANCE 0x80
#define ACPI_PROCESSOR_NOTIFY_POWER	0x81
#define ACPI_PROCESSOR_NOTIFY_THROTTLING	0x82

#define ACPI_PROCESSOR_LIMIT_USER	0
#define ACPI_PROCESSOR_LIMIT_THERMAL	1

#define _COMPONENT		ACPI_PROCESSOR_COMPONENT
ACPI_MODULE_NAME("processor_core");

MODULE_AUTHOR("Paul Diefenbaugh");
MODULE_DESCRIPTION("ACPI Processor Driver");
MODULE_LICENSE("GPL");

static int acpi_processor_add(struct acpi_device *device);
static int acpi_processor_start(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 void acpi_processor_notify(acpi_handle handle, u32 event, void *data);
static acpi_status acpi_processor_hotadd_init(acpi_handle handle, int *p_cpu);
static int acpi_processor_handle_eject(struct acpi_processor *pr);
extern int acpi_processor_tstate_has_changed(struct acpi_processor *pr);


static const struct acpi_device_id processor_device_ids[] = {
	{ACPI_PROCESSOR_HID, 0},
	{"", 0},
};
MODULE_DEVICE_TABLE(acpi, processor_device_ids);

static struct acpi_driver acpi_processor_driver = {
	.name = "processor",
	.class = ACPI_PROCESSOR_CLASS,
	.ids = processor_device_ids,
	.ops = {
		.add = acpi_processor_add,
		.remove = acpi_processor_remove,
		.start = acpi_processor_start,
		.suspend = acpi_processor_suspend,
		.resume = acpi_processor_resume,
		},
};

#define INSTALL_NOTIFY_HANDLER		1
#define UNINSTALL_NOTIFY_HANDLER	2

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

struct acpi_processor *processors[NR_CPUS];
struct acpi_processor_errata errata __read_mostly;

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

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


	if (!dev)
		return -EINVAL;

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

	switch (dev->revision) {
	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 (dev->revision) {

	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_get_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);
			pci_dev_put(dev);
		}

		/*
		 * 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_get_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;
			pci_dev_put(dev);
		}

		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 0;
}

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


	if (!pr)
		return -EINVAL;

	/*
	 * PIIX4
	 */
	dev = pci_get_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);
		pci_dev_put(dev);
	}

	return result;
}

/* --------------------------------------------------------------------------
                              Common ACPI processor functions
   -------------------------------------------------------------------------- */

/*
 * _PDC is required for a BIOS-OS handshake for most of the newer
 * ACPI processor features.
 */
static int acpi_processor_set_pdc(struct acpi_processor *pr)
{
	struct acpi_object_list *pdc_in = pr->pdc;
	acpi_status status = AE_OK;


	if (!pdc_in)
		return status;

	status = acpi_evaluate_object(pr->handle, "_PDC", pdc_in, NULL);

	if (ACPI_FAILURE(status))
		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
		    "Could not evaluate _PDC, using legacy perf. control...\n"));

	return status;
}

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

static struct proc_dir_entry *acpi_processor_dir = NULL;

static int acpi_processor_info_seq_show(struct seq_file *seq, void *offset)
{
	struct acpi_processor *pr = seq->private;


	if (!pr)
		goto end;

	seq_printf(seq, "processor id:            %d\n"
		   "acpi id:                 %d\n"
		   "bus mastering control:   %s\n"
		   "power management:        %s\n"
		   "throttling control:      %s\n"
		   "limit interface:         %s\n",
		   pr->id,
		   pr->acpi_id,
		   pr->flags.bm_control ? "yes" : "no",
		   pr->flags.power ? "yes" : "no",
		   pr->flags.throttling ? "yes" : "no",
		   pr->flags.limit ? "yes" : "no");

      end:
	return 0;
}

static int acpi_processor_info_open_fs(struct inode *inode, struct file *file)
{
	return single_open(file, acpi_processor_info_seq_show,
			   PDE(inode)->data);
}

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


	if (!acpi_device_dir(device)) {
		acpi_device_dir(device) = proc_mkdir(acpi_device_bid(device),
						     acpi_processor_dir);
		if (!acpi_device_dir(device))
			return -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)
		return -EIO;
	else {
		entry->proc_fops = &acpi_processor_info_fops;
		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)
		return -EIO;
	else {
		entry->proc_fops = &acpi_processor_throttling_fops;
		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)
		return -EIO;
	else {
		entry->proc_fops = &acpi_processor_limit_fops;
		entry->data = acpi_driver_data(device);
		entry->owner = THIS_MODULE;
	}

	return 0;
}

static int acpi_processor_remove_fs(struct acpi_device *device)
{

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

	return 0;
}

/* Use the acpiid in MADT to map cpus in case of SMP */

#ifndef CONFIG_SMP
static int get_cpu_id(acpi_handle handle, u32 acpi_id) {return -1;}
#else

static struct acpi_table_madt *madt;

static int map_lapic_id(struct acpi_subtable_header *entry,
		 u32 acpi_id, int *apic_id)
{
	struct acpi_madt_local_apic *lapic =
		(struct acpi_madt_local_apic *)entry;
	if ((lapic->lapic_flags & ACPI_MADT_ENABLED) &&
	    lapic->processor_id == acpi_id) {
		*apic_id = lapic->id;
		return 1;
	}
	return 0;
}

static int map_lsapic_id(struct acpi_subtable_header *entry,
		  u32 acpi_id, int *apic_id)
{
	struct acpi_madt_local_sapic *lsapic =
		(struct acpi_madt_local_sapic *)entry;
	/* Only check enabled APICs*/
	if (lsapic->lapic_flags & ACPI_MADT_ENABLED) {
		/* First check against id */
		if (lsapic->processor_id == acpi_id) {
			*apic_id = (lsapic->id << 8) | lsapic->eid;
			return 1;
		/* Check against optional uid */
		} else if (entry->length >= 16 &&
			lsapic->uid == acpi_id) {
			*apic_id = lsapic->uid;
			return 1;
		}
	}
	return 0;
}

static int map_madt_entry(u32 acpi_id)
{
	unsigned long madt_end, entry;
	int apic_id = -1;

	if (!madt)
		return apic_id;

	entry = (unsigned long)madt;
	madt_end = entry + madt->header.length;

	/* Parse all entries looking for a match. */

	entry += sizeof(struct acpi_table_madt);
	while (entry + sizeof(struct acpi_subtable_header) < madt_end) {
		struct acpi_subtable_header *header =
			(struct acpi_subtable_header *)entry;
		if (header->type == ACPI_MADT_TYPE_LOCAL_APIC) {
			if (map_lapic_id(header, acpi_id, &apic_id))
				break;
		} else if (header->type == ACPI_MADT_TYPE_LOCAL_SAPIC) {
			if (map_lsapic_id(header, acpi_id, &apic_id))
				break;
		}
		entry += header->length;
	}
	return apic_id;
}

static int map_mat_entry(acpi_handle handle, u32 acpi_id)
{
	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
	union acpi_object *obj;
	struct acpi_subtable_header *header;
	int apic_id = -1;

	if (ACPI_FAILURE(acpi_evaluate_object(handle, "_MAT", NULL, &buffer)))
		goto exit;

	if (!buffer.length || !buffer.pointer)
		goto exit;

	obj = buffer.pointer;
	if (obj->type != ACPI_TYPE_BUFFER ||
	    obj->buffer.length < sizeof(struct acpi_subtable_header)) {
		goto exit;
	}

	header = (struct acpi_subtable_header *)obj->buffer.pointer;
	if (header->type == ACPI_MADT_TYPE_LOCAL_APIC) {
		map_lapic_id(header, acpi_id, &apic_id);
	} else if (header->type == ACPI_MADT_TYPE_LOCAL_SAPIC) {
		map_lsapic_id(header, acpi_id, &apic_id);
	}

exit:
	if (buffer.pointer)
		kfree(buffer.pointer);
	return apic_id;
}

static int get_cpu_id(acpi_handle handle, u32 acpi_id)
{
	int i;
	int apic_id = -1;

	apic_id = map_mat_entry(handle, acpi_id);
	if (apic_id == -1)
		apic_id = map_madt_entry(acpi_id);
	if (apic_id == -1)
		return apic_id;

	for_each_possible_cpu(i) {
		if (cpu_physical_id(i) == apic_id)
			return i;
	}
	return -1;
}
#endif

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

static int acpi_processor_get_info(struct acpi_processor *pr, unsigned has_uid)
{
	acpi_status status = 0;
	union acpi_object object = { 0 };
	struct acpi_buffer buffer = { sizeof(union acpi_object), &object };
	int cpu_index;
	static int cpu0_initialized;


	if (!pr)
		return -EINVAL;

	if (num_online_cpus() > 1)
		errata.smp = TRUE;

	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_gbl_FADT.pm2_control_block && acpi_gbl_FADT.pm2_control_length) {
		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"));

	/* Check if it is a Device with HID and UID */
	if (has_uid) {
		unsigned long value;
		status = acpi_evaluate_integer(pr->handle, METHOD_NAME__UID,
						NULL, &value);
		if (ACPI_FAILURE(status)) {
			printk(KERN_ERR PREFIX "Evaluating processor _UID\n");
			return -ENODEV;
		}
		pr->acpi_id = value;
	} else {
		/*