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Commit 95cb9093 authored by Kenji Kaneshige's avatar Kenji Kaneshige Committed by Jesse Barnes
Browse files

PCI Hotplug: serialize pci_hp_register and pci_hp_deregister 



Convert the pci_hotplug_slot_list_lock, which only protected the
list of hotplug slots, to a pci_hp_mutex which now protects both
interfaces.

Signed-off-by: default avatarKenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: default avatarAlex Chiang <achiang@hp.com>
Signed-off-by: default avatarJesse Barnes <jbarnes@virtuousgeek.org>
parent 828f3768

drivers/pci/hotplug/pci_hotplug_core.c

+28 −23
Original line number Diff line number Diff line
@@ -37,6 +37,7 @@ 
#include <linux/init.h>

#include <linux/mount.h>

#include <linux/namei.h>

#include <linux/mutex.h>

#include <linux/pci.h>

#include <linux/pci_hotplug.h>

#include <asm/uaccess.h>
@@ -61,7 +62,7 @@ static int debug; 
//////////////////////////////////////////////////////////////////



static LIST_HEAD(pci_hotplug_slot_list);

static DEFINE_SPINLOCK(pci_hotplug_slot_list_lock);

static DEFINE_MUTEX(pci_hp_mutex);



/* these strings match up with the values in pci_bus_speed */

static char *pci_bus_speed_strings[] = {
@@ -530,17 +531,13 @@ static struct hotplug_slot *get_slot_from_name (const char *name) 
	struct hotplug_slot *slot;

	struct list_head *tmp;



	spin_lock(&pci_hotplug_slot_list_lock);

	list_for_each (tmp, &pci_hotplug_slot_list) {

		slot = list_entry (tmp, struct hotplug_slot, slot_list);

		if (strcmp(slot->name, name) == 0)

			goto out;

	}

	slot = NULL;

out:

	spin_unlock(&pci_hotplug_slot_list_lock);

			return slot;

	}

	return NULL;

}



/**

 * pci_hp_register - register a hotplug_slot with the PCI hotplug subsystem
@@ -570,9 +567,13 @@ int pci_hp_register(struct hotplug_slot *slot, struct pci_bus *bus, int slot_nr, 
		return -EINVAL;

	}



	mutex_lock(&pci_hp_mutex);



	/* Check if we have already registered a slot with the same name. */

	if (get_slot_from_name(name))

		return -EEXIST;

	if (get_slot_from_name(name)) {

		result = -EEXIST;

		goto out;

	}



	/*

	 * No problems if we call this interface from both ACPI_PCI_SLOT
@@ -580,13 +581,15 @@ int pci_hp_register(struct hotplug_slot *slot, struct pci_bus *bus, int slot_nr, 
	 * pci_slot, the interface will simply bump the refcount.

	 */

	pci_slot = pci_create_slot(bus, slot_nr, name, slot);

	if (IS_ERR(pci_slot))

		return PTR_ERR(pci_slot);

	if (IS_ERR(pci_slot)) {

		result = PTR_ERR(pci_slot);

		goto cleanup;

	}



	if (pci_slot->hotplug) {

		dbg("%s: already claimed\n", __func__);

		pci_destroy_slot(pci_slot);

		return -EBUSY;

		result = -EBUSY;

		goto cleanup;

	}



	slot->pci_slot = pci_slot;
@@ -597,21 +600,21 @@ int pci_hp_register(struct hotplug_slot *slot, struct pci_bus *bus, int slot_nr, 
	 */

	if (strcmp(kobject_name(&pci_slot->kobj), name)) {

		result = kobject_rename(&pci_slot->kobj, name);

		if (result) {

			pci_destroy_slot(pci_slot);

			return result;

		}

		if (result)

			goto cleanup;

	}



	spin_lock(&pci_hotplug_slot_list_lock);

	list_add(&slot->slot_list, &pci_hotplug_slot_list);

	spin_unlock(&pci_hotplug_slot_list_lock);



	result = fs_add_slot(pci_slot);

	kobject_uevent(&pci_slot->kobj, KOBJ_ADD);

	dbg("Added slot %s to the list\n", name);



out:

	mutex_unlock(&pci_hp_mutex);

	return result;

cleanup:

	pci_destroy_slot(pci_slot);

	goto out;

}



/**
@@ -631,13 +634,14 @@ int pci_hp_deregister(struct hotplug_slot *hotplug) 
	if (!hotplug)

		return -ENODEV;



	mutex_lock(&pci_hp_mutex);

	temp = get_slot_from_name(hotplug->name);

	if (temp != hotplug)

	if (temp != hotplug) {

		mutex_unlock(&pci_hp_mutex);

		return -ENODEV;

	}



	spin_lock(&pci_hotplug_slot_list_lock);

	list_del(&hotplug->slot_list);

	spin_unlock(&pci_hotplug_slot_list_lock);



	slot = hotplug->pci_slot;

	fs_remove_slot(slot);
@@ -646,6 +650,7 @@ int pci_hp_deregister(struct hotplug_slot *hotplug) 
	hotplug->release(hotplug);

	slot->hotplug = NULL;

	pci_destroy_slot(slot);

	mutex_unlock(&pci_hp_mutex);



	return 0;

}