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git.proxmox.com Git - mirror_ubuntu-zesty-kernel.git/blob - drivers/dca/dca-core.c
2 * Copyright(c) 2007 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 MODULE_LICENSE("GPL");
33 /* For now we're assuming a single, global, DCA provider for the system. */
35 static DEFINE_SPINLOCK(dca_lock
);
37 static struct dca_provider
*global_dca
= NULL
;
40 * dca_add_requester - add a dca client to the list
41 * @dev - the device that wants dca service
43 int dca_add_requester(struct device
*dev
)
51 slot
= global_dca
->ops
->add_requester(global_dca
, dev
);
52 spin_unlock(&dca_lock
);
56 err
= dca_sysfs_add_req(global_dca
, dev
, slot
);
59 global_dca
->ops
->remove_requester(global_dca
, dev
);
60 spin_unlock(&dca_lock
);
66 EXPORT_SYMBOL_GPL(dca_add_requester
);
69 * dca_remove_requester - remove a dca client from the list
70 * @dev - the device that wants dca service
72 int dca_remove_requester(struct device
*dev
)
79 slot
= global_dca
->ops
->remove_requester(global_dca
, dev
);
80 spin_unlock(&dca_lock
);
84 dca_sysfs_remove_req(global_dca
, slot
);
87 EXPORT_SYMBOL_GPL(dca_remove_requester
);
90 * dca_get_tag - return the dca tag for the given cpu
91 * @cpu - the cpuid as returned by get_cpu()
93 u8
dca_get_tag(int cpu
)
97 return global_dca
->ops
->get_tag(global_dca
, cpu
);
99 EXPORT_SYMBOL_GPL(dca_get_tag
);
102 * alloc_dca_provider - get data struct for describing a dca provider
103 * @ops - pointer to struct of dca operation function pointers
104 * @priv_size - size of extra mem to be added for provider's needs
106 struct dca_provider
*alloc_dca_provider(struct dca_ops
*ops
, int priv_size
)
108 struct dca_provider
*dca
;
111 alloc_size
= (sizeof(*dca
) + priv_size
);
112 dca
= kzalloc(alloc_size
, GFP_KERNEL
);
119 EXPORT_SYMBOL_GPL(alloc_dca_provider
);
122 * free_dca_provider - release the dca provider data struct
123 * @ops - pointer to struct of dca operation function pointers
124 * @priv_size - size of extra mem to be added for provider's needs
126 void free_dca_provider(struct dca_provider
*dca
)
130 EXPORT_SYMBOL_GPL(free_dca_provider
);
132 static BLOCKING_NOTIFIER_HEAD(dca_provider_chain
);
135 * register_dca_provider - register a dca provider
136 * @dca - struct created by alloc_dca_provider()
137 * @dev - device providing dca services
139 int register_dca_provider(struct dca_provider
*dca
, struct device
*dev
)
145 err
= dca_sysfs_add_provider(dca
, dev
);
149 blocking_notifier_call_chain(&dca_provider_chain
,
150 DCA_PROVIDER_ADD
, NULL
);
153 EXPORT_SYMBOL_GPL(register_dca_provider
);
156 * unregister_dca_provider - remove a dca provider
157 * @dca - struct created by alloc_dca_provider()
159 void unregister_dca_provider(struct dca_provider
*dca
)
163 blocking_notifier_call_chain(&dca_provider_chain
,
164 DCA_PROVIDER_REMOVE
, NULL
);
166 dca_sysfs_remove_provider(dca
);
168 EXPORT_SYMBOL_GPL(unregister_dca_provider
);
171 * dca_register_notify - register a client's notifier callback
173 void dca_register_notify(struct notifier_block
*nb
)
175 blocking_notifier_chain_register(&dca_provider_chain
, nb
);
177 EXPORT_SYMBOL_GPL(dca_register_notify
);
180 * dca_unregister_notify - remove a client's notifier callback
182 void dca_unregister_notify(struct notifier_block
*nb
)
184 blocking_notifier_chain_unregister(&dca_provider_chain
, nb
);
186 EXPORT_SYMBOL_GPL(dca_unregister_notify
);
188 static int __init
dca_init(void)
190 return dca_sysfs_init();
193 static void __exit
dca_exit(void)
198 module_init(dca_init
);
199 module_exit(dca_exit
);