[GitHub/mt8127/android_kernel_alcatel_ttab.git] / drivers / dca / dca-core.c

/*
 * Copyright(c) 2007 - 2009 Intel Corporation. All rights reserved.
 *
 * 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.
 *
 * The full GNU General Public License is included in this distribution in the
 * file called COPYING.
 */

/*
 * This driver supports an interface for DCA clients and providers to meet.
 */

#include <linux/kernel.h>
#include <linux/notifier.h>
#include <linux/device.h>
#include <linux/dca.h>
#include <linux/slab.h>

#define DCA_VERSION "1.12.1"

MODULE_VERSION(DCA_VERSION);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Intel Corporation");

static DEFINE_SPINLOCK(dca_lock);

static LIST_HEAD(dca_domains);

static BLOCKING_NOTIFIER_HEAD(dca_provider_chain);

static int dca_providers_blocked;

static struct pci_bus *dca_pci_rc_from_dev(struct device *dev)
{
	struct pci_dev *pdev = to_pci_dev(dev);
	struct pci_bus *bus = pdev->bus;

	while (bus->parent)
		bus = bus->parent;

	return bus;
}

static struct dca_domain *dca_allocate_domain(struct pci_bus *rc)
{
	struct dca_domain *domain;

	domain = kzalloc(sizeof(*domain), GFP_NOWAIT);
	if (!domain)
		return NULL;

	INIT_LIST_HEAD(&domain->dca_providers);
	domain->pci_rc = rc;

	return domain;
}

static void dca_free_domain(struct dca_domain *domain)
{
	list_del(&domain->node);
	kfree(domain);
}

static int dca_provider_ioat_ver_3_0(struct device *dev)
{
	struct pci_dev *pdev = to_pci_dev(dev);

	return ((pdev->vendor == PCI_VENDOR_ID_INTEL) &&
		((pdev->device == PCI_DEVICE_ID_INTEL_IOAT_TBG0) ||
		(pdev->device == PCI_DEVICE_ID_INTEL_IOAT_TBG1) ||
		(pdev->device == PCI_DEVICE_ID_INTEL_IOAT_TBG2) ||
		(pdev->device == PCI_DEVICE_ID_INTEL_IOAT_TBG3) ||
		(pdev->device == PCI_DEVICE_ID_INTEL_IOAT_TBG4) ||
		(pdev->device == PCI_DEVICE_ID_INTEL_IOAT_TBG5) ||
		(pdev->device == PCI_DEVICE_ID_INTEL_IOAT_TBG6) ||
		(pdev->device == PCI_DEVICE_ID_INTEL_IOAT_TBG7)));
}

static void unregister_dca_providers(void)
{
	struct dca_provider *dca, *_dca;
	struct list_head unregistered_providers;
	struct dca_domain *domain;
	unsigned long flags;

	blocking_notifier_call_chain(&dca_provider_chain,
				     DCA_PROVIDER_REMOVE, NULL);

	INIT_LIST_HEAD(&unregistered_providers);

	spin_lock_irqsave(&dca_lock, flags);

	if (list_empty(&dca_domains)) {
		spin_unlock_irqrestore(&dca_lock, flags);
		return;
	}

	/* at this point only one domain in the list is expected */
	domain = list_first_entry(&dca_domains, struct dca_domain, node);

	list_for_each_entry_safe(dca, _dca, &domain->dca_providers, node) {
		list_del(&dca->node);
		list_add(&dca->node, &unregistered_providers);
	}

	dca_free_domain(domain);

	spin_unlock_irqrestore(&dca_lock, flags);

	list_for_each_entry_safe(dca, _dca, &unregistered_providers, node) {
		dca_sysfs_remove_provider(dca);
		list_del(&dca->node);
	}
}

static struct dca_domain *dca_find_domain(struct pci_bus *rc)
{
	struct dca_domain *domain;

	list_for_each_entry(domain, &dca_domains, node)
		if (domain->pci_rc == rc)
			return domain;

	return NULL;
}

static struct dca_domain *dca_get_domain(struct device *dev)
{
	struct pci_bus *rc;
	struct dca_domain *domain;

	rc = dca_pci_rc_from_dev(dev);
	domain = dca_find_domain(rc);

	if (!domain) {
		if (dca_provider_ioat_ver_3_0(dev) && !list_empty(&dca_domains)) {
			dca_providers_blocked = 1;
		} else {
			domain = dca_allocate_domain(rc);
			if (domain)
				list_add(&domain->node, &dca_domains);
		}
	}

	return domain;
}

static struct dca_provider *dca_find_provider_by_dev(struct device *dev)
{
	struct dca_provider *dca;
	struct pci_bus *rc;
	struct dca_domain *domain;

	if (dev) {
		rc = dca_pci_rc_from_dev(dev);
		domain = dca_find_domain(rc);
		if (!domain)
			return NULL;
	} else {
		if (!list_empty(&dca_domains))
			domain = list_first_entry(&dca_domains,
						  struct dca_domain,
						  node);
		else
			return NULL;
	}

	list_for_each_entry(dca, &domain->dca_providers, node)
		if ((!dev) || (dca->ops->dev_managed(dca, dev)))
			return dca;

	return NULL;
}

/**
 * dca_add_requester - add a dca client to the list
 * @dev - the device that wants dca service
 */
int dca_add_requester(struct device *dev)
{
	struct dca_provider *dca;
	int err, slot = -ENODEV;
	unsigned long flags;
	struct pci_bus *pci_rc;
	struct dca_domain *domain;

	if (!dev)
		return -EFAULT;

	spin_lock_irqsave(&dca_lock, flags);

	/* check if the requester has not been added already */
	dca = dca_find_provider_by_dev(dev);
	if (dca) {
		spin_unlock_irqrestore(&dca_lock, flags);
		return -EEXIST;
	}

	pci_rc = dca_pci_rc_from_dev(dev);
	domain = dca_find_domain(pci_rc);
	if (!domain) {
		spin_unlock_irqrestore(&dca_lock, flags);
		return -ENODEV;
	}

	list_for_each_entry(dca, &domain->dca_providers, node) {
		slot = dca->ops->add_requester(dca, dev);
		if (slot >= 0)
			break;
	}

	spin_unlock_irqrestore(&dca_lock, flags);

	if (slot < 0)
		return slot;

	err = dca_sysfs_add_req(dca, dev, slot);
	if (err) {
		spin_lock_irqsave(&dca_lock, flags);
		if (dca == dca_find_provider_by_dev(dev))
			dca->ops->remove_requester(dca, dev);
		spin_unlock_irqrestore(&dca_lock, flags);
		return err;
	}

	return 0;
}
EXPORT_SYMBOL_GPL(dca_add_requester);

/**
 * dca_remove_requester - remove a dca client from the list
 * @dev - the device that wants dca service
 */
int dca_remove_requester(struct device *dev)
{
	struct dca_provider *dca;
	int slot;
	unsigned long flags;

	if (!dev)
		return -EFAULT;

	spin_lock_irqsave(&dca_lock, flags);
	dca = dca_find_provider_by_dev(dev);
	if (!dca) {
		spin_unlock_irqrestore(&dca_lock, flags);
		return -ENODEV;
	}
	slot = dca->ops->remove_requester(dca, dev);
	spin_unlock_irqrestore(&dca_lock, flags);

	if (slot < 0)
		return slot;

	dca_sysfs_remove_req(dca, slot);

	return 0;
}
EXPORT_SYMBOL_GPL(dca_remove_requester);

/**
 * dca_common_get_tag - return the dca tag (serves both new and old api)
 * @dev - the device that wants dca service
 * @cpu - the cpuid as returned by get_cpu()
 */
u8 dca_common_get_tag(struct device *dev, int cpu)
{
	struct dca_provider *dca;
	u8 tag;
	unsigned long flags;

	spin_lock_irqsave(&dca_lock, flags);

	dca = dca_find_provider_by_dev(dev);
	if (!dca) {
		spin_unlock_irqrestore(&dca_lock, flags);
		return -ENODEV;
	}
	tag = dca->ops->get_tag(dca, dev, cpu);

	spin_unlock_irqrestore(&dca_lock, flags);
	return tag;
}

/**
 * dca3_get_tag - return the dca tag to the requester device
 *                for the given cpu (new api)
 * @dev - the device that wants dca service
 * @cpu - the cpuid as returned by get_cpu()
 */
u8 dca3_get_tag(struct device *dev, int cpu)
{
	if (!dev)
		return -EFAULT;

	return dca_common_get_tag(dev, cpu);
}
EXPORT_SYMBOL_GPL(dca3_get_tag);

/**
 * dca_get_tag - return the dca tag for the given cpu (old api)
 * @cpu - the cpuid as returned by get_cpu()
 */
u8 dca_get_tag(int cpu)
{
	struct device *dev = NULL;

	return dca_common_get_tag(dev, cpu);
}
EXPORT_SYMBOL_GPL(dca_get_tag);

/**
 * alloc_dca_provider - get data struct for describing a dca provider
 * @ops - pointer to struct of dca operation function pointers
 * @priv_size - size of extra mem to be added for provider's needs
 */
struct dca_provider *alloc_dca_provider(struct dca_ops *ops, int priv_size)
{
	struct dca_provider *dca;
	int alloc_size;

	alloc_size = (sizeof(*dca) + priv_size);
	dca = kzalloc(alloc_size, GFP_KERNEL);
	if (!dca)
		return NULL;
	dca->ops = ops;

	return dca;
}
EXPORT_SYMBOL_GPL(alloc_dca_provider);

/**
 * free_dca_provider - release the dca provider data struct
 * @ops - pointer to struct of dca operation function pointers
 * @priv_size - size of extra mem to be added for provider's needs
 */
void free_dca_provider(struct dca_provider *dca)
{
	kfree(dca);
}
EXPORT_SYMBOL_GPL(free_dca_provider);

/**
 * register_dca_provider - register a dca provider
 * @dca - struct created by alloc_dca_provider()
 * @dev - device providing dca services
 */
int register_dca_provider(struct dca_provider *dca, struct device *dev)
{
	int err;
	unsigned long flags;
	struct dca_domain *domain;

	spin_lock_irqsave(&dca_lock, flags);
	if (dca_providers_blocked) {
		spin_unlock_irqrestore(&dca_lock, flags);
		return -ENODEV;
	}
	spin_unlock_irqrestore(&dca_lock, flags);

	err = dca_sysfs_add_provider(dca, dev);
	if (err)
		return err;

	spin_lock_irqsave(&dca_lock, flags);
	domain = dca_get_domain(dev);
	if (!domain) {
		if (dca_providers_blocked) {
			spin_unlock_irqrestore(&dca_lock, flags);
			dca_sysfs_remove_provider(dca);
			unregister_dca_providers();
		} else {
			spin_unlock_irqrestore(&dca_lock, flags);
		}
		return -ENODEV;
	}
	list_add(&dca->node, &domain->dca_providers);
	spin_unlock_irqrestore(&dca_lock, flags);

	blocking_notifier_call_chain(&dca_provider_chain,
				     DCA_PROVIDER_ADD, NULL);
	return 0;
}
EXPORT_SYMBOL_GPL(register_dca_provider);

/**
 * unregister_dca_provider - remove a dca provider
 * @dca - struct created by alloc_dca_provider()
 */
void unregister_dca_provider(struct dca_provider *dca, struct device *dev)
{
	unsigned long flags;
	struct pci_bus *pci_rc;
	struct dca_domain *domain;

	blocking_notifier_call_chain(&dca_provider_chain,
				     DCA_PROVIDER_REMOVE, NULL);

	spin_lock_irqsave(&dca_lock, flags);

	list_del(&dca->node);

	pci_rc = dca_pci_rc_from_dev(dev);
	domain = dca_find_domain(pci_rc);
	if (list_empty(&domain->dca_providers))
		dca_free_domain(domain);

	spin_unlock_irqrestore(&dca_lock, flags);

	dca_sysfs_remove_provider(dca);
}
EXPORT_SYMBOL_GPL(unregister_dca_provider);

/**
 * dca_register_notify - register a client's notifier callback
 */
void dca_register_notify(struct notifier_block *nb)
{
	blocking_notifier_chain_register(&dca_provider_chain, nb);
}
EXPORT_SYMBOL_GPL(dca_register_notify);

/**
 * dca_unregister_notify - remove a client's notifier callback
 */
void dca_unregister_notify(struct notifier_block *nb)
{
	blocking_notifier_chain_unregister(&dca_provider_chain, nb);
}
EXPORT_SYMBOL_GPL(dca_unregister_notify);

static int __init dca_init(void)
{
	pr_info("dca service started, version %s\n", DCA_VERSION);
	return dca_sysfs_init();
}

static void __exit dca_exit(void)
{
	dca_sysfs_exit();
}

arch_initcall(dca_init);
module_exit(dca_exit);
Commit	Line	Data
7589670f	1	/*
211a22ce	2	* Copyright(c) 2007 - 2009 Intel Corporation. All rights reserved.
7589670f SN	3	*
	4	* This program is free software; you can redistribute it and/or modify it
	5	* under the terms of the GNU General Public License as published by the Free
	6	* Software Foundation; either version 2 of the License, or (at your option)
	7	* any later version.
	8	*
	9	* This program is distributed in the hope that it will be useful, but WITHOUT
	10	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	11	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
	12	* more details.
	13	*
	14	* You should have received a copy of the GNU General Public License along with
	15	* this program; if not, write to the Free Software Foundation, Inc., 59
	16	* Temple Place - Suite 330, Boston, MA 02111-1307, USA.
	17	*
	18	* The full GNU General Public License is included in this distribution in the
	19	* file called COPYING.
	20	*/
	21
	22	/*
	23	* This driver supports an interface for DCA clients and providers to meet.
	24	*/
	25
	26	#include <linux/kernel.h>
	27	#include <linux/notifier.h>
	28	#include <linux/device.h>
	29	#include <linux/dca.h>
5a0e3ad6	30	#include <linux/slab.h>
7589670f	31
1a5aeeec	32	#define DCA_VERSION "1.12.1"
7589670f	33
7f1b358a MS	34	MODULE_VERSION(DCA_VERSION);
	35	MODULE_LICENSE("GPL");
	36	MODULE_AUTHOR("Intel Corporation");
7589670f SN	37
	38	static DEFINE_SPINLOCK(dca_lock);
	39
1a5aeeec	40	static LIST_HEAD(dca_domains);
7f1b358a	41
4e8cec26 SM	42	static BLOCKING_NOTIFIER_HEAD(dca_provider_chain);
	43
	44	static int dca_providers_blocked;
	45
1a5aeeec	46	static struct pci_bus dca_pci_rc_from_dev(struct device dev)
7f1b358a	47	{
1a5aeeec MS	48	struct pci_dev *pdev = to_pci_dev(dev);
1a5aeeec MS	49	struct pci_bus *bus = pdev->bus;
7f1b358a	50
1a5aeeec MS	51	while (bus->parent)
	52	bus = bus->parent;
	53
	54	return bus;
	55	}
	56
	57	static struct dca_domain dca_allocate_domain(struct pci_bus rc)
	58	{
	59	struct dca_domain *domain;
	60
	61	domain = kzalloc(sizeof(*domain), GFP_NOWAIT);
	62	if (!domain)
	63	return NULL;
	64
	65	INIT_LIST_HEAD(&domain->dca_providers);
	66	domain->pci_rc = rc;
	67
	68	return domain;
	69	}
	70
	71	static void dca_free_domain(struct dca_domain *domain)
	72	{
	73	list_del(&domain->node);
	74	kfree(domain);
	75	}
	76
4e8cec26 SM	77	static int dca_provider_ioat_ver_3_0(struct device *dev)
	78	{
	79	struct pci_dev *pdev = to_pci_dev(dev);
	80
	81	return ((pdev->vendor == PCI_VENDOR_ID_INTEL) &&
	82	((pdev->device == PCI_DEVICE_ID_INTEL_IOAT_TBG0) \|\|
	83	(pdev->device == PCI_DEVICE_ID_INTEL_IOAT_TBG1) \|\|
	84	(pdev->device == PCI_DEVICE_ID_INTEL_IOAT_TBG2) \|\|
	85	(pdev->device == PCI_DEVICE_ID_INTEL_IOAT_TBG3) \|\|
	86	(pdev->device == PCI_DEVICE_ID_INTEL_IOAT_TBG4) \|\|
	87	(pdev->device == PCI_DEVICE_ID_INTEL_IOAT_TBG5) \|\|
	88	(pdev->device == PCI_DEVICE_ID_INTEL_IOAT_TBG6) \|\|
	89	(pdev->device == PCI_DEVICE_ID_INTEL_IOAT_TBG7)));
	90	}
	91
	92	static void unregister_dca_providers(void)
	93	{
	94	struct dca_provider dca, _dca;
	95	struct list_head unregistered_providers;
	96	struct dca_domain *domain;
	97	unsigned long flags;
	98
	99	blocking_notifier_call_chain(&dca_provider_chain,
	100	DCA_PROVIDER_REMOVE, NULL);
	101
	102	INIT_LIST_HEAD(&unregistered_providers);
	103
	104	spin_lock_irqsave(&dca_lock, flags);
	105
	106	if (list_empty(&dca_domains)) {
	107	spin_unlock_irqrestore(&dca_lock, flags);
	108	return;
	109	}
	110
	111	/* at this point only one domain in the list is expected */
	112	domain = list_first_entry(&dca_domains, struct dca_domain, node);
4e8cec26 SM	113
	114	list_for_each_entry_safe(dca, _dca, &domain->dca_providers, node) {
	115	list_del(&dca->node);
	116	list_add(&dca->node, &unregistered_providers);
	117	}
	118
	119	dca_free_domain(domain);
	120
	121	spin_unlock_irqrestore(&dca_lock, flags);
	122
	123	list_for_each_entry_safe(dca, _dca, &unregistered_providers, node) {
	124	dca_sysfs_remove_provider(dca);
	125	list_del(&dca->node);
	126	}
	127	}
	128
1a5aeeec MS	129	static struct dca_domain dca_find_domain(struct pci_bus rc)
	130	{
	131	struct dca_domain *domain;
	132
	133	list_for_each_entry(domain, &dca_domains, node)
	134	if (domain->pci_rc == rc)
	135	return domain;
	136
	137	return NULL;
	138	}
	139
	140	static struct dca_domain dca_get_domain(struct device dev)
	141	{
	142	struct pci_bus *rc;
	143	struct dca_domain *domain;
	144
	145	rc = dca_pci_rc_from_dev(dev);
	146	domain = dca_find_domain(rc);
	147
	148	if (!domain) {
4e8cec26 SM	149	if (dca_provider_ioat_ver_3_0(dev) && !list_empty(&dca_domains)) {
	150	dca_providers_blocked = 1;
	151	} else {
	152	domain = dca_allocate_domain(rc);
	153	if (domain)
	154	list_add(&domain->node, &dca_domains);
	155	}
1a5aeeec MS	156	}
	157
	158	return domain;
	159	}
	160
	161	static struct dca_provider dca_find_provider_by_dev(struct device dev)
	162	{
	163	struct dca_provider *dca;
	164	struct pci_bus *rc;
	165	struct dca_domain *domain;
	166
	167	if (dev) {
	168	rc = dca_pci_rc_from_dev(dev);
	169	domain = dca_find_domain(rc);
	170	if (!domain)
	171	return NULL;
	172	} else {
	173	if (!list_empty(&dca_domains))
	174	domain = list_first_entry(&dca_domains,
	175	struct dca_domain,
	176	node);
	177	else
	178	return NULL;
7f1b358a MS	179	}
7f1b358a MS	180
1a5aeeec MS	181	list_for_each_entry(dca, &domain->dca_providers, node)
	182	if ((!dev) \|\| (dca->ops->dev_managed(dca, dev)))
	183	return dca;
	184
	185	return NULL;
7f1b358a	186	}
7589670f SN	187
	188	/**
	189	* dca_add_requester - add a dca client to the list
	190	* @dev - the device that wants dca service
	191	*/
	192	int dca_add_requester(struct device *dev)
	193	{
7f1b358a MS	194	struct dca_provider *dca;
7f1b358a MS	195	int err, slot = -ENODEV;
eb4400e3	196	unsigned long flags;
1a5aeeec MS	197	struct pci_bus *pci_rc;
1a5aeeec MS	198	struct dca_domain *domain;
7589670f	199
7f1b358a MS	200	if (!dev)
7f1b358a MS	201	return -EFAULT;
7589670f	202
eb4400e3	203	spin_lock_irqsave(&dca_lock, flags);
7f1b358a MS	204
	205	/* check if the requester has not been added already */
	206	dca = dca_find_provider_by_dev(dev);
	207	if (dca) {
eb4400e3	208	spin_unlock_irqrestore(&dca_lock, flags);
7f1b358a MS	209	return -EEXIST;
	210	}
	211
1a5aeeec MS	212	pci_rc = dca_pci_rc_from_dev(dev);
	213	domain = dca_find_domain(pci_rc);
	214	if (!domain) {
	215	spin_unlock_irqrestore(&dca_lock, flags);
	216	return -ENODEV;
	217	}
	218
	219	list_for_each_entry(dca, &domain->dca_providers, node) {
7f1b358a MS	220	slot = dca->ops->add_requester(dca, dev);
	221	if (slot >= 0)
	222	break;
	223	}
eb4400e3 MS	224
	225	spin_unlock_irqrestore(&dca_lock, flags);
	226
	227	if (slot < 0)
7589670f SN	228	return slot;
7589670f SN	229
7f1b358a	230	err = dca_sysfs_add_req(dca, dev, slot);
7589670f	231	if (err) {
eb4400e3 MS	232	spin_lock_irqsave(&dca_lock, flags);
	233	if (dca == dca_find_provider_by_dev(dev))
	234	dca->ops->remove_requester(dca, dev);
	235	spin_unlock_irqrestore(&dca_lock, flags);
7589670f SN	236	return err;
	237	}
	238
	239	return 0;
	240	}
	241	EXPORT_SYMBOL_GPL(dca_add_requester);
	242
	243	/**
	244	* dca_remove_requester - remove a dca client from the list
	245	* @dev - the device that wants dca service
	246	*/
	247	int dca_remove_requester(struct device *dev)
	248	{
7f1b358a	249	struct dca_provider *dca;
7589670f	250	int slot;
eb4400e3	251	unsigned long flags;
7f1b358a MS	252
	253	if (!dev)
	254	return -EFAULT;
7589670f	255
eb4400e3	256	spin_lock_irqsave(&dca_lock, flags);
7f1b358a MS	257	dca = dca_find_provider_by_dev(dev);
7f1b358a MS	258	if (!dca) {
eb4400e3	259	spin_unlock_irqrestore(&dca_lock, flags);
7f1b358a MS	260	return -ENODEV;
	261	}
	262	slot = dca->ops->remove_requester(dca, dev);
eb4400e3 MS	263	spin_unlock_irqrestore(&dca_lock, flags);
	264
	265	if (slot < 0)
7589670f SN	266	return slot;
7589670f SN	267
7f1b358a MS	268	dca_sysfs_remove_req(dca, slot);
7f1b358a MS	269
7589670f SN	270	return 0;
	271	}
	272	EXPORT_SYMBOL_GPL(dca_remove_requester);
	273
	274	/**
7f1b358a MS	275	* dca_common_get_tag - return the dca tag (serves both new and old api)
7f1b358a MS	276	* @dev - the device that wants dca service
7589670f SN	277	* @cpu - the cpuid as returned by get_cpu()
7589670f SN	278	*/
7f1b358a	279	u8 dca_common_get_tag(struct device *dev, int cpu)
7589670f	280	{
7f1b358a MS	281	struct dca_provider *dca;
7f1b358a MS	282	u8 tag;
eb4400e3	283	unsigned long flags;
7f1b358a	284
eb4400e3	285	spin_lock_irqsave(&dca_lock, flags);
7f1b358a MS	286
	287	dca = dca_find_provider_by_dev(dev);
	288	if (!dca) {
eb4400e3	289	spin_unlock_irqrestore(&dca_lock, flags);
7589670f	290	return -ENODEV;
7f1b358a MS	291	}
	292	tag = dca->ops->get_tag(dca, dev, cpu);
	293
eb4400e3	294	spin_unlock_irqrestore(&dca_lock, flags);
7f1b358a MS	295	return tag;
	296	}
	297
	298	/**
	299	* dca3_get_tag - return the dca tag to the requester device
	300	* for the given cpu (new api)
	301	* @dev - the device that wants dca service
	302	* @cpu - the cpuid as returned by get_cpu()
	303	*/
	304	u8 dca3_get_tag(struct device *dev, int cpu)
	305	{
	306	if (!dev)
	307	return -EFAULT;
	308
	309	return dca_common_get_tag(dev, cpu);
	310	}
	311	EXPORT_SYMBOL_GPL(dca3_get_tag);
	312
	313	/**
	314	* dca_get_tag - return the dca tag for the given cpu (old api)
	315	* @cpu - the cpuid as returned by get_cpu()
	316	*/
	317	u8 dca_get_tag(int cpu)
	318	{
	319	struct device *dev = NULL;
	320
	321	return dca_common_get_tag(dev, cpu);
7589670f SN	322	}
	323	EXPORT_SYMBOL_GPL(dca_get_tag);
	324
	325	/**
	326	* alloc_dca_provider - get data struct for describing a dca provider
	327	* @ops - pointer to struct of dca operation function pointers
	328	* @priv_size - size of extra mem to be added for provider's needs
	329	*/
	330	struct dca_provider alloc_dca_provider(struct dca_ops ops, int priv_size)
	331	{
	332	struct dca_provider *dca;
	333	int alloc_size;
	334
	335	alloc_size = (sizeof(*dca) + priv_size);
	336	dca = kzalloc(alloc_size, GFP_KERNEL);
	337	if (!dca)
	338	return NULL;
	339	dca->ops = ops;
	340
	341	return dca;
	342	}
	343	EXPORT_SYMBOL_GPL(alloc_dca_provider);
	344
	345	/**
	346	* free_dca_provider - release the dca provider data struct
	347	* @ops - pointer to struct of dca operation function pointers
	348	* @priv_size - size of extra mem to be added for provider's needs
	349	*/
	350	void free_dca_provider(struct dca_provider *dca)
	351	{
	352	kfree(dca);
	353	}
	354	EXPORT_SYMBOL_GPL(free_dca_provider);
	355
7589670f SN	356	/**
	357	* register_dca_provider - register a dca provider
	358	* @dca - struct created by alloc_dca_provider()
	359	* @dev - device providing dca services
	360	*/
	361	int register_dca_provider(struct dca_provider dca, struct device dev)
	362	{
	363	int err;
eb4400e3	364	unsigned long flags;
1a5aeeec	365	struct dca_domain *domain;
7589670f	366
4e8cec26 SM	367	spin_lock_irqsave(&dca_lock, flags);
	368	if (dca_providers_blocked) {
	369	spin_unlock_irqrestore(&dca_lock, flags);
	370	return -ENODEV;
	371	}
	372	spin_unlock_irqrestore(&dca_lock, flags);
	373
7589670f SN	374	err = dca_sysfs_add_provider(dca, dev);
	375	if (err)
	376	return err;
eb4400e3 MS	377
eb4400e3 MS	378	spin_lock_irqsave(&dca_lock, flags);
1a5aeeec MS	379	domain = dca_get_domain(dev);
1a5aeeec MS	380	if (!domain) {
4e8cec26 SM	381	if (dca_providers_blocked) {
	382	spin_unlock_irqrestore(&dca_lock, flags);
	383	dca_sysfs_remove_provider(dca);
	384	unregister_dca_providers();
	385	} else {
	386	spin_unlock_irqrestore(&dca_lock, flags);
	387	}
1a5aeeec MS	388	return -ENODEV;
	389	}
	390	list_add(&dca->node, &domain->dca_providers);
eb4400e3 MS	391	spin_unlock_irqrestore(&dca_lock, flags);
eb4400e3 MS	392
7589670f SN	393	blocking_notifier_call_chain(&dca_provider_chain,
	394	DCA_PROVIDER_ADD, NULL);
	395	return 0;
	396	}
	397	EXPORT_SYMBOL_GPL(register_dca_provider);
	398
	399	/**
	400	* unregister_dca_provider - remove a dca provider
	401	* @dca - struct created by alloc_dca_provider()
	402	*/
1a5aeeec	403	void unregister_dca_provider(struct dca_provider dca, struct device dev)
7589670f	404	{
eb4400e3	405	unsigned long flags;
1a5aeeec MS	406	struct pci_bus *pci_rc;
1a5aeeec MS	407	struct dca_domain *domain;
eb4400e3	408
7589670f SN	409	blocking_notifier_call_chain(&dca_provider_chain,
7589670f SN	410	DCA_PROVIDER_REMOVE, NULL);
eb4400e3 MS	411
eb4400e3 MS	412	spin_lock_irqsave(&dca_lock, flags);
1a5aeeec	413
7f1b358a	414	list_del(&dca->node);
1a5aeeec MS	415
	416	pci_rc = dca_pci_rc_from_dev(dev);
	417	domain = dca_find_domain(pci_rc);
	418	if (list_empty(&domain->dca_providers))
	419	dca_free_domain(domain);
	420
eb4400e3 MS	421	spin_unlock_irqrestore(&dca_lock, flags);
eb4400e3 MS	422
7589670f SN	423	dca_sysfs_remove_provider(dca);
	424	}
	425	EXPORT_SYMBOL_GPL(unregister_dca_provider);
	426
	427	/**
	428	* dca_register_notify - register a client's notifier callback
	429	*/
	430	void dca_register_notify(struct notifier_block *nb)
	431	{
	432	blocking_notifier_chain_register(&dca_provider_chain, nb);
	433	}
	434	EXPORT_SYMBOL_GPL(dca_register_notify);
	435
	436	/**
	437	* dca_unregister_notify - remove a client's notifier callback
	438	*/
	439	void dca_unregister_notify(struct notifier_block *nb)
	440	{
	441	blocking_notifier_chain_unregister(&dca_provider_chain, nb);
	442	}
	443	EXPORT_SYMBOL_GPL(dca_unregister_notify);
	444
	445	static int __init dca_init(void)
	446	{
084dac53	447	pr_info("dca service started, version %s\n", DCA_VERSION);
7589670f SN	448	return dca_sysfs_init();
	449	}
	450
	451	static void __exit dca_exit(void)
	452	{
	453	dca_sysfs_exit();
	454	}
	455
652afc27	456	arch_initcall(dca_init);
7589670f SN	457	module_exit(dca_exit);
7589670f SN	458