]>
git.proxmox.com Git - mirror_ubuntu-jammy-kernel.git/blob - drivers/dca/dca-core.c
2 * Copyright(c) 2007 - 2009 Intel Corporation. All rights reserved.
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)
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
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.
18 * The full GNU General Public License is included in this distribution in the
19 * file called COPYING.
23 * This driver supports an interface for DCA clients and providers to meet.
26 #include <linux/kernel.h>
27 #include <linux/notifier.h>
28 #include <linux/device.h>
29 #include <linux/dca.h>
31 #define DCA_VERSION "1.8"
33 MODULE_VERSION(DCA_VERSION
);
34 MODULE_LICENSE("GPL");
35 MODULE_AUTHOR("Intel Corporation");
37 static DEFINE_SPINLOCK(dca_lock
);
39 static LIST_HEAD(dca_providers
);
41 static struct dca_provider
*dca_find_provider_by_dev(struct device
*dev
)
43 struct dca_provider
*dca
, *ret
= NULL
;
45 list_for_each_entry(dca
, &dca_providers
, node
) {
46 if ((!dev
) || (dca
->ops
->dev_managed(dca
, dev
))) {
56 * dca_add_requester - add a dca client to the list
57 * @dev - the device that wants dca service
59 int dca_add_requester(struct device
*dev
)
61 struct dca_provider
*dca
;
62 int err
, slot
= -ENODEV
;
68 spin_lock_irqsave(&dca_lock
, flags
);
70 /* check if the requester has not been added already */
71 dca
= dca_find_provider_by_dev(dev
);
73 spin_unlock_irqrestore(&dca_lock
, flags
);
77 list_for_each_entry(dca
, &dca_providers
, node
) {
78 slot
= dca
->ops
->add_requester(dca
, dev
);
83 spin_unlock_irqrestore(&dca_lock
, flags
);
88 err
= dca_sysfs_add_req(dca
, dev
, slot
);
90 spin_lock_irqsave(&dca_lock
, flags
);
91 if (dca
== dca_find_provider_by_dev(dev
))
92 dca
->ops
->remove_requester(dca
, dev
);
93 spin_unlock_irqrestore(&dca_lock
, flags
);
99 EXPORT_SYMBOL_GPL(dca_add_requester
);
102 * dca_remove_requester - remove a dca client from the list
103 * @dev - the device that wants dca service
105 int dca_remove_requester(struct device
*dev
)
107 struct dca_provider
*dca
;
114 spin_lock_irqsave(&dca_lock
, flags
);
115 dca
= dca_find_provider_by_dev(dev
);
117 spin_unlock_irqrestore(&dca_lock
, flags
);
120 slot
= dca
->ops
->remove_requester(dca
, dev
);
121 spin_unlock_irqrestore(&dca_lock
, flags
);
126 dca_sysfs_remove_req(dca
, slot
);
130 EXPORT_SYMBOL_GPL(dca_remove_requester
);
133 * dca_common_get_tag - return the dca tag (serves both new and old api)
134 * @dev - the device that wants dca service
135 * @cpu - the cpuid as returned by get_cpu()
137 u8
dca_common_get_tag(struct device
*dev
, int cpu
)
139 struct dca_provider
*dca
;
143 spin_lock_irqsave(&dca_lock
, flags
);
145 dca
= dca_find_provider_by_dev(dev
);
147 spin_unlock_irqrestore(&dca_lock
, flags
);
150 tag
= dca
->ops
->get_tag(dca
, dev
, cpu
);
152 spin_unlock_irqrestore(&dca_lock
, flags
);
157 * dca3_get_tag - return the dca tag to the requester device
158 * for the given cpu (new api)
159 * @dev - the device that wants dca service
160 * @cpu - the cpuid as returned by get_cpu()
162 u8
dca3_get_tag(struct device
*dev
, int cpu
)
167 return dca_common_get_tag(dev
, cpu
);
169 EXPORT_SYMBOL_GPL(dca3_get_tag
);
172 * dca_get_tag - return the dca tag for the given cpu (old api)
173 * @cpu - the cpuid as returned by get_cpu()
175 u8
dca_get_tag(int cpu
)
177 struct device
*dev
= NULL
;
179 return dca_common_get_tag(dev
, cpu
);
181 EXPORT_SYMBOL_GPL(dca_get_tag
);
184 * alloc_dca_provider - get data struct for describing a dca provider
185 * @ops - pointer to struct of dca operation function pointers
186 * @priv_size - size of extra mem to be added for provider's needs
188 struct dca_provider
*alloc_dca_provider(struct dca_ops
*ops
, int priv_size
)
190 struct dca_provider
*dca
;
193 alloc_size
= (sizeof(*dca
) + priv_size
);
194 dca
= kzalloc(alloc_size
, GFP_KERNEL
);
201 EXPORT_SYMBOL_GPL(alloc_dca_provider
);
204 * free_dca_provider - release the dca provider data struct
205 * @ops - pointer to struct of dca operation function pointers
206 * @priv_size - size of extra mem to be added for provider's needs
208 void free_dca_provider(struct dca_provider
*dca
)
212 EXPORT_SYMBOL_GPL(free_dca_provider
);
214 static BLOCKING_NOTIFIER_HEAD(dca_provider_chain
);
217 * register_dca_provider - register a dca provider
218 * @dca - struct created by alloc_dca_provider()
219 * @dev - device providing dca services
221 int register_dca_provider(struct dca_provider
*dca
, struct device
*dev
)
226 err
= dca_sysfs_add_provider(dca
, dev
);
230 spin_lock_irqsave(&dca_lock
, flags
);
231 list_add(&dca
->node
, &dca_providers
);
232 spin_unlock_irqrestore(&dca_lock
, flags
);
234 blocking_notifier_call_chain(&dca_provider_chain
,
235 DCA_PROVIDER_ADD
, NULL
);
238 EXPORT_SYMBOL_GPL(register_dca_provider
);
241 * unregister_dca_provider - remove a dca provider
242 * @dca - struct created by alloc_dca_provider()
244 void unregister_dca_provider(struct dca_provider
*dca
)
248 blocking_notifier_call_chain(&dca_provider_chain
,
249 DCA_PROVIDER_REMOVE
, NULL
);
251 spin_lock_irqsave(&dca_lock
, flags
);
252 list_del(&dca
->node
);
253 spin_unlock_irqrestore(&dca_lock
, flags
);
255 dca_sysfs_remove_provider(dca
);
257 EXPORT_SYMBOL_GPL(unregister_dca_provider
);
260 * dca_register_notify - register a client's notifier callback
262 void dca_register_notify(struct notifier_block
*nb
)
264 blocking_notifier_chain_register(&dca_provider_chain
, nb
);
266 EXPORT_SYMBOL_GPL(dca_register_notify
);
269 * dca_unregister_notify - remove a client's notifier callback
271 void dca_unregister_notify(struct notifier_block
*nb
)
273 blocking_notifier_chain_unregister(&dca_provider_chain
, nb
);
275 EXPORT_SYMBOL_GPL(dca_unregister_notify
);
277 static int __init
dca_init(void)
279 printk(KERN_ERR
"dca service started, version %s\n", DCA_VERSION
);
280 return dca_sysfs_init();
283 static void __exit
dca_exit(void)
288 arch_initcall(dca_init
);
289 module_exit(dca_exit
);