[linux.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>
#include <linux/module.h>

#define DCA_VERSION "1.12.1"

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

static DEFINE_RAW_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);

	raw_spin_lock_irqsave(&dca_lock, flags);

	if (list_empty(&dca_domains)) {
		raw_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_move(&dca->node, &unregistered_providers);

	dca_free_domain(domain);

	raw_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;
	}

	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;

	raw_spin_lock_irqsave(&dca_lock, flags);

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

	pci_rc = dca_pci_rc_from_dev(dev);
	domain = dca_find_domain(pci_rc);
	if (!domain) {
		raw_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;
	}

	raw_spin_unlock_irqrestore(&dca_lock, flags);

	if (slot < 0)
		return slot;

	err = dca_sysfs_add_req(dca, dev, slot);
	if (err) {
		raw_spin_lock_irqsave(&dca_lock, flags);
		if (dca == dca_find_provider_by_dev(dev))
			dca->ops->remove_requester(dca, dev);
		raw_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;

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

	raw_spin_lock_irqsave(&dca_lock, flags);

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

	raw_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(const 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, *newdomain = NULL;

	raw_spin_lock_irqsave(&dca_lock, flags);
	if (dca_providers_blocked) {
		raw_spin_unlock_irqrestore(&dca_lock, flags);
		return -ENODEV;
	}
	raw_spin_unlock_irqrestore(&dca_lock, flags);

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

	raw_spin_lock_irqsave(&dca_lock, flags);
	domain = dca_get_domain(dev);
	if (!domain) {
		struct pci_bus *rc;

		if (dca_providers_blocked) {
			raw_spin_unlock_irqrestore(&dca_lock, flags);
			dca_sysfs_remove_provider(dca);
			unregister_dca_providers();
			return -ENODEV;
		}

		raw_spin_unlock_irqrestore(&dca_lock, flags);
		rc = dca_pci_rc_from_dev(dev);
		newdomain = dca_allocate_domain(rc);
		if (!newdomain)
			return -ENODEV;
		raw_spin_lock_irqsave(&dca_lock, flags);
		/* Recheck, we might have raced after dropping the lock */
		domain = dca_get_domain(dev);
		if (!domain) {
			domain = newdomain;
			newdomain = NULL;
			list_add(&domain->node, &dca_domains);
		}
	}
	list_add(&dca->node, &domain->dca_providers);
	raw_spin_unlock_irqrestore(&dca_lock, flags);

	blocking_notifier_call_chain(&dca_provider_chain,
				     DCA_PROVIDER_ADD, NULL);
	kfree(newdomain);
	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);

	raw_spin_lock_irqsave(&dca_lock, flags);

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

	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);

	raw_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>
d229807f	31	#include <linux/module.h>
7589670f	32
1a5aeeec	33	#define DCA_VERSION "1.12.1"
7589670f	34
7f1b358a MS	35	MODULE_VERSION(DCA_VERSION);
	36	MODULE_LICENSE("GPL");
	37	MODULE_AUTHOR("Intel Corporation");
7589670f	38
a1741e7f	39	static DEFINE_RAW_SPINLOCK(dca_lock);
7589670f	40
1a5aeeec	41	static LIST_HEAD(dca_domains);
7f1b358a	42
4e8cec26 SM	43	static BLOCKING_NOTIFIER_HEAD(dca_provider_chain);
	44
	45	static int dca_providers_blocked;
	46
1a5aeeec	47	static struct pci_bus dca_pci_rc_from_dev(struct device dev)
7f1b358a	48	{
1a5aeeec MS	49	struct pci_dev *pdev = to_pci_dev(dev);
1a5aeeec MS	50	struct pci_bus *bus = pdev->bus;
7f1b358a	51
1a5aeeec MS	52	while (bus->parent)
	53	bus = bus->parent;
	54
	55	return bus;
	56	}
	57
	58	static struct dca_domain dca_allocate_domain(struct pci_bus rc)
	59	{
	60	struct dca_domain *domain;
	61
	62	domain = kzalloc(sizeof(*domain), GFP_NOWAIT);
	63	if (!domain)
	64	return NULL;
	65
	66	INIT_LIST_HEAD(&domain->dca_providers);
	67	domain->pci_rc = rc;
	68
	69	return domain;
	70	}
	71
	72	static void dca_free_domain(struct dca_domain *domain)
	73	{
	74	list_del(&domain->node);
	75	kfree(domain);
	76	}
	77
4e8cec26 SM	78	static int dca_provider_ioat_ver_3_0(struct device *dev)
	79	{
	80	struct pci_dev *pdev = to_pci_dev(dev);
	81
	82	return ((pdev->vendor == PCI_VENDOR_ID_INTEL) &&
	83	((pdev->device == PCI_DEVICE_ID_INTEL_IOAT_TBG0) \|\|
	84	(pdev->device == PCI_DEVICE_ID_INTEL_IOAT_TBG1) \|\|
	85	(pdev->device == PCI_DEVICE_ID_INTEL_IOAT_TBG2) \|\|
	86	(pdev->device == PCI_DEVICE_ID_INTEL_IOAT_TBG3) \|\|
	87	(pdev->device == PCI_DEVICE_ID_INTEL_IOAT_TBG4) \|\|
	88	(pdev->device == PCI_DEVICE_ID_INTEL_IOAT_TBG5) \|\|
	89	(pdev->device == PCI_DEVICE_ID_INTEL_IOAT_TBG6) \|\|
	90	(pdev->device == PCI_DEVICE_ID_INTEL_IOAT_TBG7)));
	91	}
	92
	93	static void unregister_dca_providers(void)
	94	{
	95	struct dca_provider dca, _dca;
	96	struct list_head unregistered_providers;
	97	struct dca_domain *domain;
	98	unsigned long flags;
	99
	100	blocking_notifier_call_chain(&dca_provider_chain,
	101	DCA_PROVIDER_REMOVE, NULL);
	102
	103	INIT_LIST_HEAD(&unregistered_providers);
	104
a1741e7f	105	raw_spin_lock_irqsave(&dca_lock, flags);
4e8cec26 SM	106
4e8cec26 SM	107	if (list_empty(&dca_domains)) {
a1741e7f	108	raw_spin_unlock_irqrestore(&dca_lock, flags);
4e8cec26 SM	109	return;
	110	}
	111
	112	/* at this point only one domain in the list is expected */
	113	domain = list_first_entry(&dca_domains, struct dca_domain, node);
4e8cec26	114
3bb598fb KS	115	list_for_each_entry_safe(dca, _dca, &domain->dca_providers, node)
3bb598fb KS	116	list_move(&dca->node, &unregistered_providers);
4e8cec26 SM	117
	118	dca_free_domain(domain);
	119
a1741e7f	120	raw_spin_unlock_irqrestore(&dca_lock, flags);
4e8cec26 SM	121
	122	list_for_each_entry_safe(dca, _dca, &unregistered_providers, node) {
	123	dca_sysfs_remove_provider(dca);
	124	list_del(&dca->node);
	125	}
	126	}
	127
1a5aeeec MS	128	static struct dca_domain dca_find_domain(struct pci_bus rc)
	129	{
	130	struct dca_domain *domain;
	131
	132	list_for_each_entry(domain, &dca_domains, node)
	133	if (domain->pci_rc == rc)
	134	return domain;
	135
	136	return NULL;
	137	}
	138
	139	static struct dca_domain dca_get_domain(struct device dev)
	140	{
	141	struct pci_bus *rc;
	142	struct dca_domain *domain;
	143
	144	rc = dca_pci_rc_from_dev(dev);
	145	domain = dca_find_domain(rc);
	146
	147	if (!domain) {
a1741e7f	148	if (dca_provider_ioat_ver_3_0(dev) && !list_empty(&dca_domains))
4e8cec26	149	dca_providers_blocked = 1;
1a5aeeec MS	150	}
	151
	152	return domain;
	153	}
	154
	155	static struct dca_provider dca_find_provider_by_dev(struct device dev)
	156	{
	157	struct dca_provider *dca;
	158	struct pci_bus *rc;
	159	struct dca_domain *domain;
	160
	161	if (dev) {
	162	rc = dca_pci_rc_from_dev(dev);
	163	domain = dca_find_domain(rc);
	164	if (!domain)
	165	return NULL;
	166	} else {
	167	if (!list_empty(&dca_domains))
	168	domain = list_first_entry(&dca_domains,
	169	struct dca_domain,
	170	node);
	171	else
	172	return NULL;
7f1b358a MS	173	}
7f1b358a MS	174
1a5aeeec MS	175	list_for_each_entry(dca, &domain->dca_providers, node)
	176	if ((!dev) \|\| (dca->ops->dev_managed(dca, dev)))
	177	return dca;
	178
	179	return NULL;
7f1b358a	180	}
7589670f SN	181
	182	/**
	183	* dca_add_requester - add a dca client to the list
	184	* @dev - the device that wants dca service
	185	*/
	186	int dca_add_requester(struct device *dev)
	187	{
7f1b358a MS	188	struct dca_provider *dca;
7f1b358a MS	189	int err, slot = -ENODEV;
eb4400e3	190	unsigned long flags;
1a5aeeec MS	191	struct pci_bus *pci_rc;
1a5aeeec MS	192	struct dca_domain *domain;
7589670f	193
7f1b358a MS	194	if (!dev)
7f1b358a MS	195	return -EFAULT;
7589670f	196
a1741e7f	197	raw_spin_lock_irqsave(&dca_lock, flags);
7f1b358a MS	198
	199	/* check if the requester has not been added already */
	200	dca = dca_find_provider_by_dev(dev);
	201	if (dca) {
a1741e7f	202	raw_spin_unlock_irqrestore(&dca_lock, flags);
7f1b358a MS	203	return -EEXIST;
	204	}
	205
1a5aeeec MS	206	pci_rc = dca_pci_rc_from_dev(dev);
	207	domain = dca_find_domain(pci_rc);
	208	if (!domain) {
a1741e7f	209	raw_spin_unlock_irqrestore(&dca_lock, flags);
1a5aeeec MS	210	return -ENODEV;
	211	}
	212
	213	list_for_each_entry(dca, &domain->dca_providers, node) {
7f1b358a MS	214	slot = dca->ops->add_requester(dca, dev);
	215	if (slot >= 0)
	216	break;
	217	}
eb4400e3	218
a1741e7f	219	raw_spin_unlock_irqrestore(&dca_lock, flags);
eb4400e3 MS	220
eb4400e3 MS	221	if (slot < 0)
7589670f SN	222	return slot;
7589670f SN	223
7f1b358a	224	err = dca_sysfs_add_req(dca, dev, slot);
7589670f	225	if (err) {
a1741e7f	226	raw_spin_lock_irqsave(&dca_lock, flags);
eb4400e3 MS	227	if (dca == dca_find_provider_by_dev(dev))
eb4400e3 MS	228	dca->ops->remove_requester(dca, dev);
a1741e7f	229	raw_spin_unlock_irqrestore(&dca_lock, flags);
7589670f SN	230	return err;
	231	}
	232
	233	return 0;
	234	}
	235	EXPORT_SYMBOL_GPL(dca_add_requester);
	236
	237	/**
	238	* dca_remove_requester - remove a dca client from the list
	239	* @dev - the device that wants dca service
	240	*/
	241	int dca_remove_requester(struct device *dev)
	242	{
7f1b358a	243	struct dca_provider *dca;
7589670f	244	int slot;
eb4400e3	245	unsigned long flags;
7f1b358a MS	246
	247	if (!dev)
	248	return -EFAULT;
7589670f	249
a1741e7f	250	raw_spin_lock_irqsave(&dca_lock, flags);
7f1b358a MS	251	dca = dca_find_provider_by_dev(dev);
7f1b358a MS	252	if (!dca) {
a1741e7f	253	raw_spin_unlock_irqrestore(&dca_lock, flags);
7f1b358a MS	254	return -ENODEV;
	255	}
	256	slot = dca->ops->remove_requester(dca, dev);
a1741e7f	257	raw_spin_unlock_irqrestore(&dca_lock, flags);
eb4400e3 MS	258
eb4400e3 MS	259	if (slot < 0)
7589670f SN	260	return slot;
7589670f SN	261
7f1b358a MS	262	dca_sysfs_remove_req(dca, slot);
7f1b358a MS	263
7589670f SN	264	return 0;
	265	}
	266	EXPORT_SYMBOL_GPL(dca_remove_requester);
	267
	268	/**
7f1b358a MS	269	* dca_common_get_tag - return the dca tag (serves both new and old api)
7f1b358a MS	270	* @dev - the device that wants dca service
7589670f SN	271	* @cpu - the cpuid as returned by get_cpu()
7589670f SN	272	*/
7f1b358a	273	u8 dca_common_get_tag(struct device *dev, int cpu)
7589670f	274	{
7f1b358a MS	275	struct dca_provider *dca;
7f1b358a MS	276	u8 tag;
eb4400e3	277	unsigned long flags;
7f1b358a	278
a1741e7f	279	raw_spin_lock_irqsave(&dca_lock, flags);
7f1b358a MS	280
	281	dca = dca_find_provider_by_dev(dev);
	282	if (!dca) {
a1741e7f	283	raw_spin_unlock_irqrestore(&dca_lock, flags);
7589670f	284	return -ENODEV;
7f1b358a MS	285	}
	286	tag = dca->ops->get_tag(dca, dev, cpu);
	287
a1741e7f	288	raw_spin_unlock_irqrestore(&dca_lock, flags);
7f1b358a MS	289	return tag;
	290	}
	291
	292	/**
	293	* dca3_get_tag - return the dca tag to the requester device
	294	* for the given cpu (new api)
	295	* @dev - the device that wants dca service
	296	* @cpu - the cpuid as returned by get_cpu()
	297	*/
	298	u8 dca3_get_tag(struct device *dev, int cpu)
	299	{
	300	if (!dev)
	301	return -EFAULT;
	302
	303	return dca_common_get_tag(dev, cpu);
	304	}
	305	EXPORT_SYMBOL_GPL(dca3_get_tag);
	306
	307	/**
	308	* dca_get_tag - return the dca tag for the given cpu (old api)
	309	* @cpu - the cpuid as returned by get_cpu()
	310	*/
	311	u8 dca_get_tag(int cpu)
	312	{
	313	struct device *dev = NULL;
	314
	315	return dca_common_get_tag(dev, cpu);
7589670f SN	316	}
	317	EXPORT_SYMBOL_GPL(dca_get_tag);
	318
	319	/**
	320	* alloc_dca_provider - get data struct for describing a dca provider
	321	* @ops - pointer to struct of dca operation function pointers
	322	* @priv_size - size of extra mem to be added for provider's needs
	323	*/
2bb129eb JL	324	struct dca_provider alloc_dca_provider(const struct dca_ops ops,
2bb129eb JL	325	int priv_size)
7589670f SN	326	{
	327	struct dca_provider *dca;
	328	int alloc_size;
	329
	330	alloc_size = (sizeof(*dca) + priv_size);
	331	dca = kzalloc(alloc_size, GFP_KERNEL);
	332	if (!dca)
	333	return NULL;
	334	dca->ops = ops;
	335
	336	return dca;
	337	}
	338	EXPORT_SYMBOL_GPL(alloc_dca_provider);
	339
	340	/**
	341	* free_dca_provider - release the dca provider data struct
	342	* @ops - pointer to struct of dca operation function pointers
	343	* @priv_size - size of extra mem to be added for provider's needs
	344	*/
	345	void free_dca_provider(struct dca_provider *dca)
	346	{
	347	kfree(dca);
	348	}
	349	EXPORT_SYMBOL_GPL(free_dca_provider);
	350
7589670f SN	351	/**
	352	* register_dca_provider - register a dca provider
	353	* @dca - struct created by alloc_dca_provider()
	354	* @dev - device providing dca services
	355	*/
	356	int register_dca_provider(struct dca_provider dca, struct device dev)
	357	{
	358	int err;
eb4400e3	359	unsigned long flags;
a1741e7f	360	struct dca_domain domain, newdomain = NULL;
7589670f	361
a1741e7f	362	raw_spin_lock_irqsave(&dca_lock, flags);
4e8cec26	363	if (dca_providers_blocked) {
a1741e7f	364	raw_spin_unlock_irqrestore(&dca_lock, flags);
4e8cec26 SM	365	return -ENODEV;
4e8cec26 SM	366	}
a1741e7f	367	raw_spin_unlock_irqrestore(&dca_lock, flags);
4e8cec26	368
7589670f SN	369	err = dca_sysfs_add_provider(dca, dev);
	370	if (err)
	371	return err;
eb4400e3	372
a1741e7f	373	raw_spin_lock_irqsave(&dca_lock, flags);
1a5aeeec MS	374	domain = dca_get_domain(dev);
1a5aeeec MS	375	if (!domain) {
a1741e7f MG	376	struct pci_bus *rc;
a1741e7f MG	377
4e8cec26	378	if (dca_providers_blocked) {
a1741e7f	379	raw_spin_unlock_irqrestore(&dca_lock, flags);
4e8cec26 SM	380	dca_sysfs_remove_provider(dca);
4e8cec26 SM	381	unregister_dca_providers();
a1741e7f MG	382	return -ENODEV;
	383	}
	384
	385	raw_spin_unlock_irqrestore(&dca_lock, flags);
	386	rc = dca_pci_rc_from_dev(dev);
	387	newdomain = dca_allocate_domain(rc);
	388	if (!newdomain)
	389	return -ENODEV;
	390	raw_spin_lock_irqsave(&dca_lock, flags);
	391	/* Recheck, we might have raced after dropping the lock */
	392	domain = dca_get_domain(dev);
	393	if (!domain) {
	394	domain = newdomain;
	395	newdomain = NULL;
	396	list_add(&domain->node, &dca_domains);
4e8cec26	397	}
1a5aeeec MS	398	}
1a5aeeec MS	399	list_add(&dca->node, &domain->dca_providers);
a1741e7f	400	raw_spin_unlock_irqrestore(&dca_lock, flags);
eb4400e3	401
7589670f SN	402	blocking_notifier_call_chain(&dca_provider_chain,
7589670f SN	403	DCA_PROVIDER_ADD, NULL);
a1741e7f	404	kfree(newdomain);
7589670f SN	405	return 0;
	406	}
	407	EXPORT_SYMBOL_GPL(register_dca_provider);
	408
	409	/**
	410	* unregister_dca_provider - remove a dca provider
	411	* @dca - struct created by alloc_dca_provider()
	412	*/
1a5aeeec	413	void unregister_dca_provider(struct dca_provider dca, struct device dev)
7589670f	414	{
eb4400e3	415	unsigned long flags;
1a5aeeec MS	416	struct pci_bus *pci_rc;
1a5aeeec MS	417	struct dca_domain *domain;
eb4400e3	418
7589670f SN	419	blocking_notifier_call_chain(&dca_provider_chain,
7589670f SN	420	DCA_PROVIDER_REMOVE, NULL);
eb4400e3	421
a1741e7f	422	raw_spin_lock_irqsave(&dca_lock, flags);
1a5aeeec	423
c419fcfd MS	424	if (list_empty(&dca_domains)) {
	425	raw_spin_unlock_irqrestore(&dca_lock, flags);
	426	return;
	427	}
	428
7f1b358a	429	list_del(&dca->node);
1a5aeeec MS	430
	431	pci_rc = dca_pci_rc_from_dev(dev);
	432	domain = dca_find_domain(pci_rc);
	433	if (list_empty(&domain->dca_providers))
	434	dca_free_domain(domain);
	435
a1741e7f	436	raw_spin_unlock_irqrestore(&dca_lock, flags);
eb4400e3	437
7589670f SN	438	dca_sysfs_remove_provider(dca);
	439	}
	440	EXPORT_SYMBOL_GPL(unregister_dca_provider);
	441
	442	/**
	443	* dca_register_notify - register a client's notifier callback
	444	*/
	445	void dca_register_notify(struct notifier_block *nb)
	446	{
	447	blocking_notifier_chain_register(&dca_provider_chain, nb);
	448	}
	449	EXPORT_SYMBOL_GPL(dca_register_notify);
	450
	451	/**
	452	* dca_unregister_notify - remove a client's notifier callback
	453	*/
	454	void dca_unregister_notify(struct notifier_block *nb)
	455	{
	456	blocking_notifier_chain_unregister(&dca_provider_chain, nb);
	457	}
	458	EXPORT_SYMBOL_GPL(dca_unregister_notify);
	459
	460	static int __init dca_init(void)
	461	{
084dac53	462	pr_info("dca service started, version %s\n", DCA_VERSION);
7589670f SN	463	return dca_sysfs_init();
	464	}
	465
	466	static void __exit dca_exit(void)
	467	{
	468	dca_sysfs_exit();
	469	}
	470
652afc27	471	arch_initcall(dca_init);
7589670f SN	472	module_exit(dca_exit);
7589670f SN	473