Linux-2.6.12-rc2v2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!

1 files changed, 904 insertions, 0 deletions

diff --git a/drivers/acpi/pci_link.c b/drivers/acpi/pci_link.c
new file mode 100644
index 00000000000..520b28ad074
--- /dev/null
+++ b/drivers/acpi/pci_link.c
@@ -0,0 +1,904 @@
+/*
+ *  pci_link.c - ACPI PCI Interrupt Link Device Driver ($Revision: 34 $)
+ *
+ *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
+ *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
+ *  Copyright (C) 2002       Dominik Brodowski <devel@brodo.de>
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ *
+ *  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. Support more than one IRQ resource entry per link device (index).
+ *	2. Implement start/stop mechanism and use ACPI Bus Driver facilities
+ *	   for IRQ management (e.g. start()->_SRS).
+ */
+
+#include <linux/sysdev.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/types.h>
+#include <linux/proc_fs.h>
+#include <linux/spinlock.h>
+#include <linux/pm.h>
+#include <linux/pci.h>
+
+#include <acpi/acpi_bus.h>
+#include <acpi/acpi_drivers.h>
+
+
+#define _COMPONENT		ACPI_PCI_COMPONENT
+ACPI_MODULE_NAME		("pci_link")
+
+#define ACPI_PCI_LINK_CLASS		"pci_irq_routing"
+#define ACPI_PCI_LINK_HID		"PNP0C0F"
+#define ACPI_PCI_LINK_DRIVER_NAME	"ACPI PCI Interrupt Link Driver"
+#define ACPI_PCI_LINK_DEVICE_NAME	"PCI Interrupt Link"
+#define ACPI_PCI_LINK_FILE_INFO		"info"
+#define ACPI_PCI_LINK_FILE_STATUS	"state"
+
+#define ACPI_PCI_LINK_MAX_POSSIBLE 16
+
+static int acpi_pci_link_add (struct acpi_device *device);
+static int acpi_pci_link_remove (struct acpi_device *device, int type);
+
+static struct acpi_driver acpi_pci_link_driver = {
+	.name =		ACPI_PCI_LINK_DRIVER_NAME,
+	.class =	ACPI_PCI_LINK_CLASS,
+	.ids =		ACPI_PCI_LINK_HID,
+	.ops =		{
+				.add =    acpi_pci_link_add,
+				.remove = acpi_pci_link_remove,
+			},
+};
+
+struct acpi_pci_link_irq {
+	u8			active;			/* Current IRQ */
+	u8			edge_level;		/* All IRQs */
+	u8			active_high_low;	/* All IRQs */
+	u8			initialized;
+	u8			resource_type;
+	u8			possible_count;
+	u8			possible[ACPI_PCI_LINK_MAX_POSSIBLE];
+};
+
+struct acpi_pci_link {
+	struct list_head	node;
+	struct acpi_device	*device;
+	acpi_handle		handle;
+	struct acpi_pci_link_irq irq;
+};
+
+static struct {
+	int			count;
+	struct list_head	entries;
+}				acpi_link;
+
+
+/* --------------------------------------------------------------------------
+                            PCI Link Device Management
+   -------------------------------------------------------------------------- */
+
+/*
+ * set context (link) possible list from resource list
+ */
+static acpi_status
+acpi_pci_link_check_possible (
+	struct acpi_resource	*resource,
+	void			*context)
+{
+	struct acpi_pci_link	*link = (struct acpi_pci_link *) context;
+	u32			i = 0;
+
+	ACPI_FUNCTION_TRACE("acpi_pci_link_check_possible");
+
+	switch (resource->id) {
+	case ACPI_RSTYPE_START_DPF:
+		return_ACPI_STATUS(AE_OK);
+	case ACPI_RSTYPE_IRQ:
+	{
+		struct acpi_resource_irq *p = &resource->data.irq;
+		if (!p || !p->number_of_interrupts) {
+			ACPI_DEBUG_PRINT((ACPI_DB_WARN, "Blank IRQ resource\n"));
+			return_ACPI_STATUS(AE_OK);
+		}
+		for (i = 0; (i<p->number_of_interrupts && i<ACPI_PCI_LINK_MAX_POSSIBLE); i++) {
+			if (!p->interrupts[i]) {
+				ACPI_DEBUG_PRINT((ACPI_DB_WARN, "Invalid IRQ %d\n", p->interrupts[i]));
+				continue;
+			}
+			link->irq.possible[i] = p->interrupts[i];
+			link->irq.possible_count++;
+		}
+		link->irq.edge_level = p->edge_level;
+		link->irq.active_high_low = p->active_high_low;
+		link->irq.resource_type = ACPI_RSTYPE_IRQ;
+		break;
+	}
+	case ACPI_RSTYPE_EXT_IRQ:
+	{
+		struct acpi_resource_ext_irq *p = &resource->data.extended_irq;
+		if (!p || !p->number_of_interrupts) {
+			ACPI_DEBUG_PRINT((ACPI_DB_WARN, 
+				"Blank EXT IRQ resource\n"));
+			return_ACPI_STATUS(AE_OK);
+		}
+		for (i = 0; (i<p->number_of_interrupts && i<ACPI_PCI_LINK_MAX_POSSIBLE); i++) {
+			if (!p->interrupts[i]) {
+				ACPI_DEBUG_PRINT((ACPI_DB_WARN, "Invalid IRQ %d\n", p->interrupts[i]));
+				continue;
+			}
+			link->irq.possible[i] = p->interrupts[i];
+			link->irq.possible_count++;
+		}
+		link->irq.edge_level = p->edge_level;
+		link->irq.active_high_low = p->active_high_low;
+		link->irq.resource_type = ACPI_RSTYPE_EXT_IRQ;
+		break;
+	}
+	default:
+		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, 
+			"Resource is not an IRQ entry\n"));
+		return_ACPI_STATUS(AE_OK);
+	}
+
+	return_ACPI_STATUS(AE_CTRL_TERMINATE);
+}
+
+
+static int
+acpi_pci_link_get_possible (
+	struct acpi_pci_link	*link)
+{
+	acpi_status		status;
+
+	ACPI_FUNCTION_TRACE("acpi_pci_link_get_possible");
+
+	if (!link)
+		return_VALUE(-EINVAL);
+
+	status = acpi_walk_resources(link->handle, METHOD_NAME__PRS,
+			acpi_pci_link_check_possible, link);
+	if (ACPI_FAILURE(status)) {
+		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error evaluating _PRS\n"));
+		return_VALUE(-ENODEV);
+	}
+
+	ACPI_DEBUG_PRINT((ACPI_DB_INFO, 
+		"Found %d possible IRQs\n", link->irq.possible_count));
+
+	return_VALUE(0);
+}
+
+
+static acpi_status
+acpi_pci_link_check_current (
+	struct acpi_resource	*resource,
+	void			*context)
+{
+	int			*irq = (int *) context;
+
+	ACPI_FUNCTION_TRACE("acpi_pci_link_check_current");
+
+	switch (resource->id) {
+	case ACPI_RSTYPE_IRQ:
+	{
+		struct acpi_resource_irq *p = &resource->data.irq;
+		if (!p || !p->number_of_interrupts) {
+			/*
+			 * IRQ descriptors may have no IRQ# bits set,
+			 * particularly those those w/ _STA disabled
+			 */
+			ACPI_DEBUG_PRINT((ACPI_DB_INFO,
+				"Blank IRQ resource\n")); 
+			return_ACPI_STATUS(AE_OK);
+		}
+		*irq = p->interrupts[0];
+		break;
+	}
+	case ACPI_RSTYPE_EXT_IRQ:
+	{
+		struct acpi_resource_ext_irq *p = &resource->data.extended_irq;
+		if (!p || !p->number_of_interrupts) {
+			/*
+			 * extended IRQ descriptors must
+			 * return at least 1 IRQ
+			 */
+			ACPI_DEBUG_PRINT((ACPI_DB_WARN,
+				"Blank EXT IRQ resource\n"));
+			return_ACPI_STATUS(AE_OK);
+		}
+		*irq = p->interrupts[0];
+		break;
+	}
+	default:
+		ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
+			"Resource isn't an IRQ\n"));
+		return_ACPI_STATUS(AE_OK);
+	}
+	return_ACPI_STATUS(AE_CTRL_TERMINATE);
+}
+
+/*
+ * Run _CRS and set link->irq.active
+ *
+ * return value:
+ * 0 - success
+ * !0 - failure
+ */
+static int
+acpi_pci_link_get_current (
+	struct acpi_pci_link	*link)
+{
+	int			result = 0;
+	acpi_status		status = AE_OK;
+	int			irq = 0;
+
+	ACPI_FUNCTION_TRACE("acpi_pci_link_get_current");
+
+	if (!link || !link->handle)
+		return_VALUE(-EINVAL);
+
+	link->irq.active = 0;
+
+	/* in practice, status disabled is meaningless, ignore it */
+	if (acpi_strict) {
+		/* Query _STA, set link->device->status */
+		result = acpi_bus_get_status(link->device);
+		if (result) {
+			ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Unable to read status\n"));
+			goto end;
+		}
+
+		if (!link->device->status.enabled) {
+			ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Link disabled\n"));
+			return_VALUE(0);
+		}
+	}
+
+	/* 
+	 * Query and parse _CRS to get the current IRQ assignment. 
+	 */
+
+	status = acpi_walk_resources(link->handle, METHOD_NAME__CRS,
+			acpi_pci_link_check_current, &irq);
+	if (ACPI_FAILURE(status)) {
+		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error evaluating _CRS\n"));
+		result = -ENODEV;
+		goto end;
+	}
+
+	if (acpi_strict && !irq) {
+		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "_CRS returned 0\n"));
+		result = -ENODEV;
+	}
+
+	link->irq.active = irq;
+
+	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Link at IRQ %d \n", link->irq.active));
+
+end:
+	return_VALUE(result);
+}
+
+static int
+acpi_pci_link_set (
+	struct acpi_pci_link	*link,
+	int			irq)
+{
+	int			result = 0;
+	acpi_status		status = AE_OK;
+	struct {
+		struct acpi_resource	res;
+		struct acpi_resource	end;
+	}    *resource;
+	struct acpi_buffer	buffer = {0, NULL};
+
+	ACPI_FUNCTION_TRACE("acpi_pci_link_set");
+
+	if (!link || !irq)
+		return_VALUE(-EINVAL);
+
+	resource = kmalloc( sizeof(*resource)+1, GFP_KERNEL);
+	if(!resource)
+		return_VALUE(-ENOMEM);
+
+	memset(resource, 0, sizeof(*resource)+1);
+	buffer.length = sizeof(*resource) +1;
+	buffer.pointer = resource;
+
+	switch(link->irq.resource_type) {
+	case ACPI_RSTYPE_IRQ:
+		resource->res.id = ACPI_RSTYPE_IRQ;
+		resource->res.length = sizeof(struct acpi_resource);
+		resource->res.data.irq.edge_level = link->irq.edge_level;
+		resource->res.data.irq.active_high_low = link->irq.active_high_low;
+		if (link->irq.edge_level == ACPI_EDGE_SENSITIVE)
+			resource->res.data.irq.shared_exclusive = ACPI_EXCLUSIVE;
+		else
+			resource->res.data.irq.shared_exclusive = ACPI_SHARED;
+		resource->res.data.irq.number_of_interrupts = 1;
+		resource->res.data.irq.interrupts[0] = irq;
+		break;
+	   
+	case ACPI_RSTYPE_EXT_IRQ:
+		resource->res.id = ACPI_RSTYPE_EXT_IRQ;
+		resource->res.length = sizeof(struct acpi_resource);
+		resource->res.data.extended_irq.producer_consumer = ACPI_CONSUMER;
+		resource->res.data.extended_irq.edge_level = link->irq.edge_level;
+		resource->res.data.extended_irq.active_high_low = link->irq.active_high_low;
+		if (link->irq.edge_level == ACPI_EDGE_SENSITIVE)
+			resource->res.data.irq.shared_exclusive = ACPI_EXCLUSIVE;
+		else
+			resource->res.data.irq.shared_exclusive = ACPI_SHARED;
+		resource->res.data.extended_irq.number_of_interrupts = 1;
+		resource->res.data.extended_irq.interrupts[0] = irq;
+		/* ignore resource_source, it's optional */
+		break;
+	default:
+		printk("ACPI BUG: resource_type %d\n", link->irq.resource_type);
+		result = -EINVAL;
+		goto end;
+
+	}
+	resource->end.id = ACPI_RSTYPE_END_TAG;
+
+	/* Attempt to set the resource */
+	status = acpi_set_current_resources(link->handle, &buffer);
+
+	/* check for total failure */
+	if (ACPI_FAILURE(status)) {
+		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error evaluating _SRS\n"));
+		result = -ENODEV;
+		goto end;
+	}
+
+	/* Query _STA, set device->status */
+	result = acpi_bus_get_status(link->device);
+	if (result) {
+		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Unable to read status\n"));
+		goto end;
+	}
+	if (!link->device->status.enabled) {
+		printk(KERN_WARNING PREFIX
+			"%s [%s] disabled and referenced, BIOS bug.\n",
+			acpi_device_name(link->device),
+			acpi_device_bid(link->device));
+	}
+
+	/* Query _CRS, set link->irq.active */
+	result = acpi_pci_link_get_current(link);
+	if (result) {
+		goto end;
+	}
+
+	/*
+	 * Is current setting not what we set?
+	 * set link->irq.active
+	 */
+	if (link->irq.active != irq) {
+		/*
+		 * policy: when _CRS doesn't return what we just _SRS
+		 * assume _SRS worked and override _CRS value.
+		 */
+		printk(KERN_WARNING PREFIX 
+			"%s [%s] BIOS reported IRQ %d, using IRQ %d\n",
+			acpi_device_name(link->device),
+			acpi_device_bid(link->device),
+			link->irq.active, irq);
+		link->irq.active = irq;
+	}
+
+	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Set IRQ %d\n", link->irq.active));
+	
+end:
+	kfree(resource);
+	return_VALUE(result);
+}
+
+
+/* --------------------------------------------------------------------------
+                            PCI Link IRQ Management
+   -------------------------------------------------------------------------- */
+
+/*
+ * "acpi_irq_balance" (default in APIC mode) enables ACPI to use PIC Interrupt
+ * Link Devices to move the PIRQs around to minimize sharing.
+ * 
+ * "acpi_irq_nobalance" (default in PIC mode) tells ACPI not to move any PIC IRQs
+ * that the BIOS has already set to active.  This is necessary because
+ * ACPI has no automatic means of knowing what ISA IRQs are used.  Note that
+ * if the BIOS doesn't set a Link Device active, ACPI needs to program it
+ * even if acpi_irq_nobalance is set.
+ *
+ * A tables of penalties avoids directing PCI interrupts to well known
+ * ISA IRQs. Boot params are available to over-ride the default table:
+ *
+ * List interrupts that are free for PCI use.
+ * acpi_irq_pci=n[,m]
+ *
+ * List interrupts that should not be used for PCI:
+ * acpi_irq_isa=n[,m]
+ *
+ * Note that PCI IRQ routers have a list of possible IRQs,
+ * which may not include the IRQs this table says are available.
+ * 
+ * Since this heuristic can't tell the difference between a link
+ * that no device will attach to, vs. a link which may be shared
+ * by multiple active devices -- it is not optimal.
+ *
+ * If interrupt performance is that important, get an IO-APIC system
+ * with a pin dedicated to each device.  Or for that matter, an MSI
+ * enabled system.
+ */
+
+#define ACPI_MAX_IRQS		256
+#define ACPI_MAX_ISA_IRQ	16
+
+#define PIRQ_PENALTY_PCI_AVAILABLE	(0)
+#define PIRQ_PENALTY_PCI_POSSIBLE	(16*16)
+#define PIRQ_PENALTY_PCI_USING		(16*16*16)
+#define PIRQ_PENALTY_ISA_TYPICAL	(16*16*16*16)
+#define PIRQ_PENALTY_ISA_USED		(16*16*16*16*16)
+#define PIRQ_PENALTY_ISA_ALWAYS		(16*16*16*16*16*16)
+
+static int acpi_irq_penalty[ACPI_MAX_IRQS] = {
+	PIRQ_PENALTY_ISA_ALWAYS,	/* IRQ0 timer */
+	PIRQ_PENALTY_ISA_ALWAYS,	/* IRQ1 keyboard */
+	PIRQ_PENALTY_ISA_ALWAYS,	/* IRQ2 cascade */
+	PIRQ_PENALTY_ISA_TYPICAL,	/* IRQ3	serial */
+	PIRQ_PENALTY_ISA_TYPICAL,	/* IRQ4	serial */
+	PIRQ_PENALTY_ISA_TYPICAL,	/* IRQ5 sometimes SoundBlaster */
+	PIRQ_PENALTY_ISA_TYPICAL,	/* IRQ6 */
+	PIRQ_PENALTY_ISA_TYPICAL,	/* IRQ7 parallel, spurious */
+	PIRQ_PENALTY_ISA_TYPICAL,	/* IRQ8 rtc, sometimes */
+	PIRQ_PENALTY_PCI_AVAILABLE,	/* IRQ9  PCI, often acpi */
+	PIRQ_PENALTY_PCI_AVAILABLE,	/* IRQ10 PCI */
+	PIRQ_PENALTY_PCI_AVAILABLE,	/* IRQ11 PCI */
+	PIRQ_PENALTY_ISA_USED,	/* IRQ12 mouse */
+	PIRQ_PENALTY_ISA_USED,	/* IRQ13 fpe, sometimes */
+	PIRQ_PENALTY_ISA_USED,	/* IRQ14 ide0 */
+	PIRQ_PENALTY_ISA_USED,	/* IRQ15 ide1 */
+			/* >IRQ15 */
+};
+
+int __init
+acpi_irq_penalty_init(void)
+{
+	struct list_head	*node = NULL;
+	struct acpi_pci_link    *link = NULL;
+	int			i = 0;
+
+	ACPI_FUNCTION_TRACE("acpi_irq_penalty_init");
+
+	/*
+	 * Update penalties to facilitate IRQ balancing.
+	 */
+	list_for_each(node, &acpi_link.entries) {
+
+		link = list_entry(node, struct acpi_pci_link, node);
+		if (!link) {
+			ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid link context\n"));
+			continue;
+		}
+
+		/*
+		 * reflect the possible and active irqs in the penalty table --
+		 * useful for breaking ties.
+		 */
+		if (link->irq.possible_count) {
+			int penalty = PIRQ_PENALTY_PCI_POSSIBLE / link->irq.possible_count;
+
+			for (i = 0; i < link->irq.possible_count; i++) {
+				if (link->irq.possible[i] < ACPI_MAX_ISA_IRQ)
+					acpi_irq_penalty[link->irq.possible[i]] += penalty;
+			}
+
+		} else if (link->irq.active) {
+			acpi_irq_penalty[link->irq.active] += PIRQ_PENALTY_PCI_POSSIBLE;
+		}
+	}
+	/* Add a penalty for the SCI */
+	acpi_irq_penalty[acpi_fadt.sci_int] += PIRQ_PENALTY_PCI_USING;
+
+	return_VALUE(0);
+}
+
+static int acpi_irq_balance;	/* 0: static, 1: balance */
+
+static int acpi_pci_link_allocate(
+	struct acpi_pci_link	*link)
+{
+	int			irq;
+	int			i;
+
+	ACPI_FUNCTION_TRACE("acpi_pci_link_allocate");
+
+	if (link->irq.initialized)
+		return_VALUE(0);
+
+	/*
+	 * search for active IRQ in list of possible IRQs.
+	 */
+	for (i = 0; i < link->irq.possible_count; ++i) {
+		if (link->irq.active == link->irq.possible[i])
+			break;
+	}
+	/*
+	 * forget active IRQ that is not in possible list
+	 */
+	if (i == link->irq.possible_count) {
+		if (acpi_strict)
+			printk(KERN_WARNING PREFIX "_CRS %d not found"
+				" in _PRS\n", link->irq.active);
+		link->irq.active = 0;
+	}
+
+	/*
+	 * if active found, use it; else pick entry from end of possible list.
+	 */
+	if (link->irq.active) {
+		irq = link->irq.active;
+	} else {
+		irq = link->irq.possible[link->irq.possible_count - 1];
+	}
+
+	if (acpi_irq_balance || !link->irq.active) {
+		/*
+		 * Select the best IRQ.  This is done in reverse to promote
+		 * the use of IRQs 9, 10, 11, and >15.
+		 */
+		for (i = (link->irq.possible_count - 1); i >= 0; i--) {
+			if (acpi_irq_penalty[irq] > acpi_irq_penalty[link->irq.possible[i]])
+				irq = link->irq.possible[i];
+		}
+	}
+
+	/* Attempt to enable the link device at this IRQ. */
+	if (acpi_pci_link_set(link, irq)) {
+		printk(PREFIX "Unable to set IRQ for %s [%s] (likely buggy ACPI BIOS).\n"
+				"Try pci=noacpi or acpi=off\n",
+			acpi_device_name(link->device),
+			acpi_device_bid(link->device));
+		return_VALUE(-ENODEV);
+	} else {
+		acpi_irq_penalty[link->irq.active] += PIRQ_PENALTY_PCI_USING;
+		printk(PREFIX "%s [%s] enabled at IRQ %d\n", 
+			acpi_device_name(link->device),
+			acpi_device_bid(link->device), link->irq.active);
+	}
+
+	link->irq.initialized = 1;
+
+	return_VALUE(0);
+}
+
+/*
+ * acpi_pci_link_get_irq
+ * success: return IRQ >= 0
+ * failure: return -1
+ */
+
+int
+acpi_pci_link_get_irq (
+	acpi_handle		handle,
+	int			index,
+	int			*edge_level,
+	int			*active_high_low,
+	char			**name)
+{
+	int                     result = 0;
+	struct acpi_device	*device = NULL;
+	struct acpi_pci_link	*link = NULL;
+
+	ACPI_FUNCTION_TRACE("acpi_pci_link_get_irq");
+
+	result = acpi_bus_get_device(handle, &device);
+	if (result) {
+		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid link device\n"));
+		return_VALUE(-1);
+	}
+
+	link = (struct acpi_pci_link *) acpi_driver_data(device);
+	if (!link) {
+		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid link context\n"));
+		return_VALUE(-1);
+	}
+
+	/* TBD: Support multiple index (IRQ) entries per Link Device */
+	if (index) {
+		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid index %d\n", index));
+		return_VALUE(-1);
+	}
+
+	if (acpi_pci_link_allocate(link))
+		return_VALUE(-1);
+	   
+	if (!link->irq.active) {
+		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Link active IRQ is 0!\n"));
+		return_VALUE(-1);
+	}
+
+	if (edge_level) *edge_level = link->irq.edge_level;
+	if (active_high_low) *active_high_low = link->irq.active_high_low;
+	if (name) *name = acpi_device_bid(link->device);
+	return_VALUE(link->irq.active);
+}
+
+
+/* --------------------------------------------------------------------------
+                                 Driver Interface
+   -------------------------------------------------------------------------- */
+
+static int
+acpi_pci_link_add (
+	struct acpi_device *device)
+{
+	int			result = 0;
+	struct acpi_pci_link	*link = NULL;
+	int			i = 0;
+	int			found = 0;
+
+	ACPI_FUNCTION_TRACE("acpi_pci_link_add");
+
+	if (!device)
+		return_VALUE(-EINVAL);
+
+	link = kmalloc(sizeof(struct acpi_pci_link), GFP_KERNEL);
+	if (!link)
+		return_VALUE(-ENOMEM);
+	memset(link, 0, sizeof(struct acpi_pci_link));
+
+	link->device = device;
+	link->handle = device->handle;
+	strcpy(acpi_device_name(device), ACPI_PCI_LINK_DEVICE_NAME);
+	strcpy(acpi_device_class(device), ACPI_PCI_LINK_CLASS);
+	acpi_driver_data(device) = link;
+
+	result = acpi_pci_link_get_possible(link);
+	if (result)
+		goto end;
+
+	/* query and set link->irq.active */
+	acpi_pci_link_get_current(link);
+
+	printk(PREFIX "%s [%s] (IRQs", acpi_device_name(device),
+		acpi_device_bid(device));
+	for (i = 0; i < link->irq.possible_count; i++) {
+		if (link->irq.active == link->irq.possible[i]) {
+			printk(" *%d", link->irq.possible[i]);
+			found = 1;
+		}
+		else
+			printk(" %d", link->irq.possible[i]);
+	}
+
+	printk(")");
+
+	if (!found)
+		printk(" *%d", link->irq.active);
+
+	if(!link->device->status.enabled)
+		printk(", disabled.");
+
+	printk("\n");
+
+	/* TBD: Acquire/release lock */
+	list_add_tail(&link->node, &acpi_link.entries);
+	acpi_link.count++;
+
+end:
+	/* disable all links -- to be activated on use */
+	acpi_ut_evaluate_object(link->handle, "_DIS", 0, NULL);
+
+	if (result)
+		kfree(link);
+
+	return_VALUE(result);
+}
+
+
+static int
+acpi_pci_link_resume (
+	struct acpi_pci_link	*link)
+{
+	ACPI_FUNCTION_TRACE("acpi_pci_link_resume");
+	
+	if (link->irq.active && link->irq.initialized)
+		return_VALUE(acpi_pci_link_set(link, link->irq.active));
+	else
+		return_VALUE(0);
+}
+
+
+static int
+irqrouter_resume(
+	struct sys_device *dev)
+{
+	struct list_head        *node = NULL;
+	struct acpi_pci_link    *link = NULL;
+
+	ACPI_FUNCTION_TRACE("irqrouter_resume");
+
+	list_for_each(node, &acpi_link.entries) {
+
+		link = list_entry(node, struct acpi_pci_link, node);
+		if (!link) {
+			ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid link context\n"));
+			continue;
+		}
+
+		acpi_pci_link_resume(link);
+	}
+	return_VALUE(0);
+}
+
+
+static int
+acpi_pci_link_remove (
+	struct acpi_device	*device,
+	int			type)
+{
+	struct acpi_pci_link *link = NULL;
+
+	ACPI_FUNCTION_TRACE("acpi_pci_link_remove");
+
+	if (!device || !acpi_driver_data(device))
+		return_VALUE(-EINVAL);
+
+	link = (struct acpi_pci_link *) acpi_driver_data(device);
+
+	/* TBD: Acquire/release lock */
+	list_del(&link->node);
+
+	kfree(link);
+
+	return_VALUE(0);
+}
+
+/*
+ * modify acpi_irq_penalty[] from cmdline
+ */
+static int __init acpi_irq_penalty_update(char *str, int used)
+{
+	int i;
+
+	for (i = 0; i < 16; i++) {
+		int retval;
+		int irq;
+
+		retval = get_option(&str,&irq);
+
+		if (!retval)
+			break;	/* no number found */
+
+		if (irq < 0)
+			continue;
+		
+		if (irq >= ACPI_MAX_IRQS)
+			continue;
+
+		if (used)
+			acpi_irq_penalty[irq] += PIRQ_PENALTY_ISA_USED;
+		else
+			acpi_irq_penalty[irq] = PIRQ_PENALTY_PCI_AVAILABLE;
+
+		if (retval != 2)	/* no next number */
+			break;
+	}
+	return 1;
+}
+
+/*
+ * We'd like PNP to call this routine for the
+ * single ISA_USED value for each legacy device.
+ * But instead it calls us with each POSSIBLE setting.
+ * There is no ISA_POSSIBLE weight, so we simply use
+ * the (small) PCI_USING penalty.
+ */
+void acpi_penalize_isa_irq(int irq)
+{
+	acpi_irq_penalty[irq] += PIRQ_PENALTY_PCI_USING;
+}
+
+/*
+ * Over-ride default table to reserve additional IRQs for use by ISA
+ * e.g. acpi_irq_isa=5
+ * Useful for telling ACPI how not to interfere with your ISA sound card.
+ */
+static int __init acpi_irq_isa(char *str)
+{
+	return acpi_irq_penalty_update(str, 1);
+}
+__setup("acpi_irq_isa=", acpi_irq_isa);
+
+/*
+ * Over-ride default table to free additional IRQs for use by PCI
+ * e.g. acpi_irq_pci=7,15
+ * Used for acpi_irq_balance to free up IRQs to reduce PCI IRQ sharing.
+ */
+static int __init acpi_irq_pci(char *str)
+{
+	return acpi_irq_penalty_update(str, 0);
+}
+__setup("acpi_irq_pci=", acpi_irq_pci);
+
+static int __init acpi_irq_nobalance_set(char *str)
+{
+	acpi_irq_balance = 0;
+	return 1;
+}
+__setup("acpi_irq_nobalance", acpi_irq_nobalance_set);
+
+int __init acpi_irq_balance_set(char *str)
+{
+	acpi_irq_balance = 1;
+	return 1;
+}
+__setup("acpi_irq_balance", acpi_irq_balance_set);
+
+
+static struct sysdev_class irqrouter_sysdev_class = {
+        set_kset_name("irqrouter"),
+        .resume = irqrouter_resume,
+};
+
+
+static struct sys_device device_irqrouter = {
+	.id     = 0,
+	.cls    = &irqrouter_sysdev_class,
+};
+
+
+static int __init irqrouter_init_sysfs(void)
+{
+	int error;
+
+	ACPI_FUNCTION_TRACE("irqrouter_init_sysfs");
+
+	if (acpi_disabled || acpi_noirq)
+		return_VALUE(0);
+
+	error = sysdev_class_register(&irqrouter_sysdev_class);
+	if (!error)
+		error = sysdev_register(&device_irqrouter);
+
+	return_VALUE(error);
+}                                        
+
+device_initcall(irqrouter_init_sysfs);
+
+
+static int __init acpi_pci_link_init (void)
+{
+	ACPI_FUNCTION_TRACE("acpi_pci_link_init");
+
+	if (acpi_noirq)
+		return_VALUE(0);
+
+	acpi_link.count = 0;
+	INIT_LIST_HEAD(&acpi_link.entries);
+
+	if (acpi_bus_register_driver(&acpi_pci_link_driver) < 0)
+		return_VALUE(-ENODEV);
+
+	return_VALUE(0);
+}
+
+subsys_initcall(acpi_pci_link_init);