1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
|
/*
* Copyright(c) 2007 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>
MODULE_LICENSE("GPL");
/* For now we're assuming a single, global, DCA provider for the system. */
static DEFINE_SPINLOCK(dca_lock);
static struct dca_provider *global_dca = 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)
{
int err, slot;
if (!global_dca)
return -ENODEV;
spin_lock(&dca_lock);
slot = global_dca->ops->add_requester(global_dca, dev);
spin_unlock(&dca_lock);
if (slot < 0)
return slot;
err = dca_sysfs_add_req(global_dca, dev, slot);
if (err) {
spin_lock(&dca_lock);
global_dca->ops->remove_requester(global_dca, dev);
spin_unlock(&dca_lock);
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)
{
int slot;
if (!global_dca)
return -ENODEV;
spin_lock(&dca_lock);
slot = global_dca->ops->remove_requester(global_dca, dev);
spin_unlock(&dca_lock);
if (slot < 0)
return slot;
dca_sysfs_remove_req(global_dca, slot);
return 0;
}
EXPORT_SYMBOL_GPL(dca_remove_requester);
/**
* dca_get_tag - return the dca tag for the given cpu
* @cpu - the cpuid as returned by get_cpu()
*/
u8 dca_get_tag(int cpu)
{
if (!global_dca)
return -ENODEV;
return global_dca->ops->get_tag(global_dca, 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);
static BLOCKING_NOTIFIER_HEAD(dca_provider_chain);
/**
* 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;
if (global_dca)
return -EEXIST;
err = dca_sysfs_add_provider(dca, dev);
if (err)
return err;
global_dca = dca;
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)
{
if (!global_dca)
return;
blocking_notifier_call_chain(&dca_provider_chain,
DCA_PROVIDER_REMOVE, NULL);
global_dca = NULL;
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)
{
return dca_sysfs_init();
}
static void __exit dca_exit(void)
{
dca_sysfs_exit();
}
module_init(dca_init);
module_exit(dca_exit);
|
