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Commit 8344b568 authored by Alex Chiang's avatar Alex Chiang Committed by Jesse Barnes
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PCI: ACPI PCI slot detection driver



Detect all physical PCI slots as described by ACPI, and create entries in
/sys/bus/pci/slots/.

Not all physical slots are hotpluggable, and the acpiphp module does not
detect them.  Now we know the physical PCI geography of our system, without
caring about hotplug.

[kaneshige.kenji@jp.fujitsu.com: export-kobject_rename-for-pci_hotplug_core]
Signed-off-by: default avatarKenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Acked-by: default avatarGreg KH <greg@kroah.com>
[akpm@linux-foundation.org: build fix]
[akpm@linux-foundation.org: fix build with CONFIG_DMI=n]
Signed-off-by: default avatarAlex Chiang <achiang@hp.com>
Cc: Greg KH <greg@kroah.com>
Cc: Kristen Carlson Accardi <kristen.c.accardi@intel.com>
Cc: Len Brown <lenb@kernel.org>
Acked-by: default avatarLen Brown <len.brown@intel.com>
Acked-by: default avatarKenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarJesse Barnes <jbarnes@virtuousgeek.org>
parent f46753c5
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+9 −0
Original line number Diff line number Diff line
@@ -338,6 +338,15 @@ config ACPI_EC
	  the battery and thermal drivers.  If you are compiling for a 
	  mobile system, say Y.

config ACPI_PCI_SLOT
	tristate "PCI slot detection driver"
	default n
	help
	  This driver will attempt to discover all PCI slots in your system,
	  and creates entries in /sys/bus/pci/slots/. This feature can
	  help you correlate PCI bus addresses with the physical geography
	  of your slots. If you are unsure, say N.

config ACPI_POWER
	bool
	default y
+1 −0
Original line number Diff line number Diff line
@@ -48,6 +48,7 @@ obj-$(CONFIG_ACPI_DOCK) += dock.o
obj-$(CONFIG_ACPI_BAY)		+= bay.o
obj-$(CONFIG_ACPI_VIDEO)	+= video.o
obj-y				+= pci_root.o pci_link.o pci_irq.o pci_bind.o
obj-$(CONFIG_ACPI_PCI_SLOT)	+= pci_slot.o
obj-$(CONFIG_ACPI_POWER)	+= power.o
obj-$(CONFIG_ACPI_PROCESSOR)	+= processor.o
obj-$(CONFIG_ACPI_CONTAINER)	+= container.o
+368 −0
Original line number Diff line number Diff line
/*
 *  pci_slot.c - ACPI PCI Slot Driver
 *
 *  The code here is heavily leveraged from the acpiphp module.
 *  Thanks to Matthew Wilcox <matthew@wil.cx> for much guidance.
 *  Thanks to Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com> for code
 *  review and fixes.
 *
 *  Copyright (C) 2007 Alex Chiang <achiang@hp.com>
 *  Copyright (C) 2007 Hewlett-Packard Development Company, L.P.
 *
 *  This program is free software; you can redistribute it and/or modify it
 *  under the terms and conditions of the GNU General Public License,
 *  version 2, as published by the Free Software Foundation.
 *
 *  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.,
 *  51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/types.h>
#include <linux/pci.h>
#include <linux/acpi.h>
#include <acpi/acpi_bus.h>
#include <acpi/acpi_drivers.h>

static int debug;
static int check_sta_before_sun;

#define DRIVER_VERSION 	"0.1"
#define DRIVER_AUTHOR	"Alex Chiang <achiang@hp.com>"
#define DRIVER_DESC	"ACPI PCI Slot Detection Driver"
MODULE_AUTHOR(DRIVER_AUTHOR);
MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_LICENSE("GPL");
MODULE_PARM_DESC(debug, "Debugging mode enabled or not");
module_param(debug, bool, 0644);

#define _COMPONENT		ACPI_PCI_COMPONENT
ACPI_MODULE_NAME("pci_slot");

#define MY_NAME "pci_slot"
#define err(format, arg...) printk(KERN_ERR "%s: " format , MY_NAME , ## arg)
#define info(format, arg...) printk(KERN_INFO "%s: " format , MY_NAME , ## arg)
#define dbg(format, arg...)					\
	do {							\
		if (debug)					\
			printk(KERN_DEBUG "%s: " format,	\
				MY_NAME , ## arg);		\
	} while (0)

#define SLOT_NAME_SIZE 20		/* Inspired by #define in acpiphp.h */

struct acpi_pci_slot {
	acpi_handle root_handle;	/* handle of the root bridge */
	struct pci_slot *pci_slot;	/* corresponding pci_slot */
	struct list_head list;		/* node in the list of slots */
};

static int acpi_pci_slot_add(acpi_handle handle);
static void acpi_pci_slot_remove(acpi_handle handle);

static LIST_HEAD(slot_list);
static DEFINE_MUTEX(slot_list_lock);
static struct acpi_pci_driver acpi_pci_slot_driver = {
	.add = acpi_pci_slot_add,
	.remove = acpi_pci_slot_remove,
};

static int
check_slot(acpi_handle handle, int *device, unsigned long *sun)
{
	int retval = 0;
	unsigned long adr, sta;
	acpi_status status;
	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };

	acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
	dbg("Checking slot on path: %s\n", (char *)buffer.pointer);

	if (check_sta_before_sun) {
		/* If SxFy doesn't have _STA, we just assume it's there */
		status = acpi_evaluate_integer(handle, "_STA", NULL, &sta);
		if (ACPI_SUCCESS(status) && !(sta & ACPI_STA_DEVICE_PRESENT)) {
			retval = -1;
			goto out;
		}
	}

	status = acpi_evaluate_integer(handle, "_ADR", NULL, &adr);
	if (ACPI_FAILURE(status)) {
		dbg("_ADR returned %d on %s\n", status, (char *)buffer.pointer);
		retval = -1;
		goto out;
	}

	*device = (adr >> 16) & 0xffff;

	/* No _SUN == not a slot == bail */
	status = acpi_evaluate_integer(handle, "_SUN", NULL, sun);
	if (ACPI_FAILURE(status)) {
		dbg("_SUN returned %d on %s\n", status, (char *)buffer.pointer);
		retval = -1;
		goto out;
	}

out:
	kfree(buffer.pointer);
	return retval;
}

struct callback_args {
	acpi_walk_callback	user_function;	/* only for walk_p2p_bridge */
	struct pci_bus		*pci_bus;
	acpi_handle		root_handle;
};

/*
 * register_slot
 *
 * Called once for each SxFy object in the namespace. Don't worry about
 * calling pci_create_slot multiple times for the same pci_bus:device,
 * since each subsequent call simply bumps the refcount on the pci_slot.
 *
 * The number of calls to pci_destroy_slot from unregister_slot is
 * symmetrical.
 */
static acpi_status
register_slot(acpi_handle handle, u32 lvl, void *context, void **rv)
{
	int device;
	unsigned long sun;
	char name[SLOT_NAME_SIZE];
	struct acpi_pci_slot *slot;
	struct pci_slot *pci_slot;
	struct callback_args *parent_context = context;
	struct pci_bus *pci_bus = parent_context->pci_bus;

	if (check_slot(handle, &device, &sun))
		return AE_OK;

	slot = kmalloc(sizeof(*slot), GFP_KERNEL);
	if (!slot) {
		err("%s: cannot allocate memory\n", __func__);
		return AE_OK;
	}

	snprintf(name, sizeof(name), "%u", (u32)sun);
	pci_slot = pci_create_slot(pci_bus, device, name);
	if (IS_ERR(pci_slot)) {
		err("pci_create_slot returned %ld\n", PTR_ERR(pci_slot));
		kfree(slot);
	}

	slot->root_handle = parent_context->root_handle;
	slot->pci_slot = pci_slot;
	INIT_LIST_HEAD(&slot->list);
	mutex_lock(&slot_list_lock);
	list_add(&slot->list, &slot_list);
	mutex_unlock(&slot_list_lock);

	dbg("pci_slot: %p, pci_bus: %x, device: %d, name: %s\n",
		pci_slot, pci_bus->number, device, name);

	return AE_OK;
}

/*
 * walk_p2p_bridge - discover and walk p2p bridges
 * @handle: points to an acpi_pci_root
 * @context: p2p_bridge_context pointer
 *
 * Note that when we call ourselves recursively, we pass a different
 * value of pci_bus in the child_context.
 */
static acpi_status
walk_p2p_bridge(acpi_handle handle, u32 lvl, void *context, void **rv)
{
	int device, function;
	unsigned long adr;
	acpi_status status;
	acpi_handle dummy_handle;
	acpi_walk_callback user_function;

	struct pci_dev *dev;
	struct pci_bus *pci_bus;
	struct callback_args child_context;
	struct callback_args *parent_context = context;

	pci_bus = parent_context->pci_bus;
	user_function = parent_context->user_function;

	status = acpi_get_handle(handle, "_ADR", &dummy_handle);
	if (ACPI_FAILURE(status))
		return AE_OK;

	status = acpi_evaluate_integer(handle, "_ADR", NULL, &adr);
	if (ACPI_FAILURE(status))
		return AE_OK;

	device = (adr >> 16) & 0xffff;
	function = adr & 0xffff;

	dev = pci_get_slot(pci_bus, PCI_DEVFN(device, function));
	if (!dev || !dev->subordinate)
		goto out;

	child_context.pci_bus = dev->subordinate;
	child_context.user_function = user_function;
	child_context.root_handle = parent_context->root_handle;

	dbg("p2p bridge walk, pci_bus = %x\n", dev->subordinate->number);
	status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, (u32)1,
				     user_function, &child_context, NULL);
	if (ACPI_FAILURE(status))
		goto out;

	status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, (u32)1,
				     walk_p2p_bridge, &child_context, NULL);
out:
	pci_dev_put(dev);
	return AE_OK;
}

/*
 * walk_root_bridge - generic root bridge walker
 * @handle: points to an acpi_pci_root
 * @user_function: user callback for slot objects
 *
 * Call user_function for all objects underneath this root bridge.
 * Walk p2p bridges underneath us and call user_function on those too.
 */
static int
walk_root_bridge(acpi_handle handle, acpi_walk_callback user_function)
{
	int seg, bus;
	unsigned long tmp;
	acpi_status status;
	acpi_handle dummy_handle;
	struct pci_bus *pci_bus;
	struct callback_args context;

	/* If the bridge doesn't have _STA, we assume it is always there */
	status = acpi_get_handle(handle, "_STA", &dummy_handle);
	if (ACPI_SUCCESS(status)) {
		status = acpi_evaluate_integer(handle, "_STA", NULL, &tmp);
		if (ACPI_FAILURE(status)) {
			info("%s: _STA evaluation failure\n", __func__);
			return 0;
		}
		if ((tmp & ACPI_STA_DEVICE_FUNCTIONING) == 0)
			/* don't register this object */
			return 0;
	}

	status = acpi_evaluate_integer(handle, "_SEG", NULL, &tmp);
	seg = ACPI_SUCCESS(status) ? tmp : 0;

	status = acpi_evaluate_integer(handle, "_BBN", NULL, &tmp);
	bus = ACPI_SUCCESS(status) ? tmp : 0;

	pci_bus = pci_find_bus(seg, bus);
	if (!pci_bus)
		return 0;

	context.pci_bus = pci_bus;
	context.user_function = user_function;
	context.root_handle = handle;

	dbg("root bridge walk, pci_bus = %x\n", pci_bus->number);
	status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, (u32)1,
				     user_function, &context, NULL);
	if (ACPI_FAILURE(status))
		return status;

	status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, (u32)1,
				     walk_p2p_bridge, &context, NULL);
	if (ACPI_FAILURE(status))
		err("%s: walk_p2p_bridge failure - %d\n", __func__, status);

	return status;
}

/*
 * acpi_pci_slot_add
 * @handle: points to an acpi_pci_root
 */
static int
acpi_pci_slot_add(acpi_handle handle)
{
	acpi_status status;

	status = walk_root_bridge(handle, register_slot);
	if (ACPI_FAILURE(status))
		err("%s: register_slot failure - %d\n", __func__, status);

	return status;
}

/*
 * acpi_pci_slot_remove
 * @handle: points to an acpi_pci_root
 */
static void
acpi_pci_slot_remove(acpi_handle handle)
{
	struct acpi_pci_slot *slot, *tmp;

	mutex_lock(&slot_list_lock);
	list_for_each_entry_safe(slot, tmp, &slot_list, list) {
		if (slot->root_handle == handle) {
			list_del(&slot->list);
			pci_destroy_slot(slot->pci_slot);
			kfree(slot);
		}
	}
	mutex_unlock(&slot_list_lock);
}

static int do_sta_before_sun(const struct dmi_system_id *d)
{
	info("%s detected: will evaluate _STA before calling _SUN\n", d->ident);
	check_sta_before_sun = 1;
	return 0;
}

static struct dmi_system_id acpi_pci_slot_dmi_table[] __initdata = {
	/*
	 * Fujitsu Primequest machines will return 1023 to indicate an
	 * error if the _SUN method is evaluated on SxFy objects that
	 * are not present (as indicated by _STA), so for those machines,
	 * we want to check _STA before evaluating _SUN.
	 */
	{
	 .callback = do_sta_before_sun,
	 .ident = "Fujitsu PRIMEQUEST",
	 .matches = {
		DMI_MATCH(DMI_BIOS_VENDOR, "FUJITSU LIMITED"),
		DMI_MATCH(DMI_BIOS_VERSION, "PRIMEQUEST"),
		},
	},
	{}
};

static int __init
acpi_pci_slot_init(void)
{
	dmi_check_system(acpi_pci_slot_dmi_table);
	acpi_pci_register_driver(&acpi_pci_slot_driver);
	return 0;
}

static void __exit
acpi_pci_slot_exit(void)
{
	acpi_pci_unregister_driver(&acpi_pci_slot_driver);
}

module_init(acpi_pci_slot_init);
module_exit(acpi_pci_slot_exit);
+16 −0
Original line number Diff line number Diff line
@@ -572,6 +572,11 @@ int pci_hp_register(struct hotplug_slot *slot, struct pci_bus *bus, int slot_nr)
	if (tmp)
		return -EEXIST;

	/*
	 * No problems if we call this interface from both ACPI_PCI_SLOT
	 * driver and call it here again. If we've already created the
	 * pci_slot, the interface will simply bump the refcount.
	 */
	pci_slot = pci_create_slot(bus, slot_nr, slot->name);
	if (IS_ERR(pci_slot))
		return PTR_ERR(pci_slot);
@@ -585,6 +590,17 @@ int pci_hp_register(struct hotplug_slot *slot, struct pci_bus *bus, int slot_nr)
	slot->pci_slot = pci_slot;
	pci_slot->hotplug = slot;

	/*
	 * Allow pcihp drivers to override the ACPI_PCI_SLOT name.
	 */
	if (strcmp(kobject_name(&pci_slot->kobj), slot->name)) {
		result = kobject_rename(&pci_slot->kobj, slot->name);
		if (result) {
			pci_destroy_slot(pci_slot);
			return result;
		}
	}

	spin_lock(&pci_hotplug_slot_list_lock);
	list_add(&slot->slot_list, &pci_hotplug_slot_list);
	spin_unlock(&pci_hotplug_slot_list_lock);
+1 −0
Original line number Diff line number Diff line
@@ -439,6 +439,7 @@ int kobject_rename(struct kobject *kobj, const char *new_name)

	return error;
}
EXPORT_SYMBOL_GPL(kobject_rename);

/**
 * kobject_move - move object to another parent
+1 −1

File changed.

Contains only whitespace changes.

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