Commit | Line | Data |
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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> | |
30 | ||
1a5aeeec | 31 | #define DCA_VERSION "1.12.1" |
7589670f | 32 | |
7f1b358a MS |
33 | MODULE_VERSION(DCA_VERSION); |
34 | MODULE_LICENSE("GPL"); | |
35 | MODULE_AUTHOR("Intel Corporation"); | |
7589670f SN |
36 | |
37 | static DEFINE_SPINLOCK(dca_lock); | |
38 | ||
1a5aeeec | 39 | static LIST_HEAD(dca_domains); |
7f1b358a | 40 | |
1a5aeeec | 41 | static struct pci_bus *dca_pci_rc_from_dev(struct device *dev) |
7f1b358a | 42 | { |
1a5aeeec MS |
43 | struct pci_dev *pdev = to_pci_dev(dev); |
44 | struct pci_bus *bus = pdev->bus; | |
7f1b358a | 45 | |
1a5aeeec MS |
46 | while (bus->parent) |
47 | bus = bus->parent; | |
48 | ||
49 | return bus; | |
50 | } | |
51 | ||
52 | static struct dca_domain *dca_allocate_domain(struct pci_bus *rc) | |
53 | { | |
54 | struct dca_domain *domain; | |
55 | ||
56 | domain = kzalloc(sizeof(*domain), GFP_NOWAIT); | |
57 | if (!domain) | |
58 | return NULL; | |
59 | ||
60 | INIT_LIST_HEAD(&domain->dca_providers); | |
61 | domain->pci_rc = rc; | |
62 | ||
63 | return domain; | |
64 | } | |
65 | ||
66 | static void dca_free_domain(struct dca_domain *domain) | |
67 | { | |
68 | list_del(&domain->node); | |
69 | kfree(domain); | |
70 | } | |
71 | ||
72 | static struct dca_domain *dca_find_domain(struct pci_bus *rc) | |
73 | { | |
74 | struct dca_domain *domain; | |
75 | ||
76 | list_for_each_entry(domain, &dca_domains, node) | |
77 | if (domain->pci_rc == rc) | |
78 | return domain; | |
79 | ||
80 | return NULL; | |
81 | } | |
82 | ||
83 | static struct dca_domain *dca_get_domain(struct device *dev) | |
84 | { | |
85 | struct pci_bus *rc; | |
86 | struct dca_domain *domain; | |
87 | ||
88 | rc = dca_pci_rc_from_dev(dev); | |
89 | domain = dca_find_domain(rc); | |
90 | ||
91 | if (!domain) { | |
92 | domain = dca_allocate_domain(rc); | |
93 | if (domain) | |
94 | list_add(&domain->node, &dca_domains); | |
95 | } | |
96 | ||
97 | return domain; | |
98 | } | |
99 | ||
100 | static struct dca_provider *dca_find_provider_by_dev(struct device *dev) | |
101 | { | |
102 | struct dca_provider *dca; | |
103 | struct pci_bus *rc; | |
104 | struct dca_domain *domain; | |
105 | ||
106 | if (dev) { | |
107 | rc = dca_pci_rc_from_dev(dev); | |
108 | domain = dca_find_domain(rc); | |
109 | if (!domain) | |
110 | return NULL; | |
111 | } else { | |
112 | if (!list_empty(&dca_domains)) | |
113 | domain = list_first_entry(&dca_domains, | |
114 | struct dca_domain, | |
115 | node); | |
116 | else | |
117 | return NULL; | |
7f1b358a MS |
118 | } |
119 | ||
1a5aeeec MS |
120 | list_for_each_entry(dca, &domain->dca_providers, node) |
121 | if ((!dev) || (dca->ops->dev_managed(dca, dev))) | |
122 | return dca; | |
123 | ||
124 | return NULL; | |
7f1b358a | 125 | } |
7589670f SN |
126 | |
127 | /** | |
128 | * dca_add_requester - add a dca client to the list | |
129 | * @dev - the device that wants dca service | |
130 | */ | |
131 | int dca_add_requester(struct device *dev) | |
132 | { | |
7f1b358a MS |
133 | struct dca_provider *dca; |
134 | int err, slot = -ENODEV; | |
eb4400e3 | 135 | unsigned long flags; |
1a5aeeec MS |
136 | struct pci_bus *pci_rc; |
137 | struct dca_domain *domain; | |
7589670f | 138 | |
7f1b358a MS |
139 | if (!dev) |
140 | return -EFAULT; | |
7589670f | 141 | |
eb4400e3 | 142 | spin_lock_irqsave(&dca_lock, flags); |
7f1b358a MS |
143 | |
144 | /* check if the requester has not been added already */ | |
145 | dca = dca_find_provider_by_dev(dev); | |
146 | if (dca) { | |
eb4400e3 | 147 | spin_unlock_irqrestore(&dca_lock, flags); |
7f1b358a MS |
148 | return -EEXIST; |
149 | } | |
150 | ||
1a5aeeec MS |
151 | pci_rc = dca_pci_rc_from_dev(dev); |
152 | domain = dca_find_domain(pci_rc); | |
153 | if (!domain) { | |
154 | spin_unlock_irqrestore(&dca_lock, flags); | |
155 | return -ENODEV; | |
156 | } | |
157 | ||
158 | list_for_each_entry(dca, &domain->dca_providers, node) { | |
7f1b358a MS |
159 | slot = dca->ops->add_requester(dca, dev); |
160 | if (slot >= 0) | |
161 | break; | |
162 | } | |
eb4400e3 MS |
163 | |
164 | spin_unlock_irqrestore(&dca_lock, flags); | |
165 | ||
166 | if (slot < 0) | |
7589670f SN |
167 | return slot; |
168 | ||
7f1b358a | 169 | err = dca_sysfs_add_req(dca, dev, slot); |
7589670f | 170 | if (err) { |
eb4400e3 MS |
171 | spin_lock_irqsave(&dca_lock, flags); |
172 | if (dca == dca_find_provider_by_dev(dev)) | |
173 | dca->ops->remove_requester(dca, dev); | |
174 | spin_unlock_irqrestore(&dca_lock, flags); | |
7589670f SN |
175 | return err; |
176 | } | |
177 | ||
178 | return 0; | |
179 | } | |
180 | EXPORT_SYMBOL_GPL(dca_add_requester); | |
181 | ||
182 | /** | |
183 | * dca_remove_requester - remove a dca client from the list | |
184 | * @dev - the device that wants dca service | |
185 | */ | |
186 | int dca_remove_requester(struct device *dev) | |
187 | { | |
7f1b358a | 188 | struct dca_provider *dca; |
7589670f | 189 | int slot; |
eb4400e3 | 190 | unsigned long flags; |
7f1b358a MS |
191 | |
192 | if (!dev) | |
193 | return -EFAULT; | |
7589670f | 194 | |
eb4400e3 | 195 | spin_lock_irqsave(&dca_lock, flags); |
7f1b358a MS |
196 | dca = dca_find_provider_by_dev(dev); |
197 | if (!dca) { | |
eb4400e3 | 198 | spin_unlock_irqrestore(&dca_lock, flags); |
7f1b358a MS |
199 | return -ENODEV; |
200 | } | |
201 | slot = dca->ops->remove_requester(dca, dev); | |
eb4400e3 MS |
202 | spin_unlock_irqrestore(&dca_lock, flags); |
203 | ||
204 | if (slot < 0) | |
7589670f SN |
205 | return slot; |
206 | ||
7f1b358a MS |
207 | dca_sysfs_remove_req(dca, slot); |
208 | ||
7589670f SN |
209 | return 0; |
210 | } | |
211 | EXPORT_SYMBOL_GPL(dca_remove_requester); | |
212 | ||
213 | /** | |
7f1b358a MS |
214 | * dca_common_get_tag - return the dca tag (serves both new and old api) |
215 | * @dev - the device that wants dca service | |
7589670f SN |
216 | * @cpu - the cpuid as returned by get_cpu() |
217 | */ | |
7f1b358a | 218 | u8 dca_common_get_tag(struct device *dev, int cpu) |
7589670f | 219 | { |
7f1b358a MS |
220 | struct dca_provider *dca; |
221 | u8 tag; | |
eb4400e3 | 222 | unsigned long flags; |
7f1b358a | 223 | |
eb4400e3 | 224 | spin_lock_irqsave(&dca_lock, flags); |
7f1b358a MS |
225 | |
226 | dca = dca_find_provider_by_dev(dev); | |
227 | if (!dca) { | |
eb4400e3 | 228 | spin_unlock_irqrestore(&dca_lock, flags); |
7589670f | 229 | return -ENODEV; |
7f1b358a MS |
230 | } |
231 | tag = dca->ops->get_tag(dca, dev, cpu); | |
232 | ||
eb4400e3 | 233 | spin_unlock_irqrestore(&dca_lock, flags); |
7f1b358a MS |
234 | return tag; |
235 | } | |
236 | ||
237 | /** | |
238 | * dca3_get_tag - return the dca tag to the requester device | |
239 | * for the given cpu (new api) | |
240 | * @dev - the device that wants dca service | |
241 | * @cpu - the cpuid as returned by get_cpu() | |
242 | */ | |
243 | u8 dca3_get_tag(struct device *dev, int cpu) | |
244 | { | |
245 | if (!dev) | |
246 | return -EFAULT; | |
247 | ||
248 | return dca_common_get_tag(dev, cpu); | |
249 | } | |
250 | EXPORT_SYMBOL_GPL(dca3_get_tag); | |
251 | ||
252 | /** | |
253 | * dca_get_tag - return the dca tag for the given cpu (old api) | |
254 | * @cpu - the cpuid as returned by get_cpu() | |
255 | */ | |
256 | u8 dca_get_tag(int cpu) | |
257 | { | |
258 | struct device *dev = NULL; | |
259 | ||
260 | return dca_common_get_tag(dev, cpu); | |
7589670f SN |
261 | } |
262 | EXPORT_SYMBOL_GPL(dca_get_tag); | |
263 | ||
264 | /** | |
265 | * alloc_dca_provider - get data struct for describing a dca provider | |
266 | * @ops - pointer to struct of dca operation function pointers | |
267 | * @priv_size - size of extra mem to be added for provider's needs | |
268 | */ | |
269 | struct dca_provider *alloc_dca_provider(struct dca_ops *ops, int priv_size) | |
270 | { | |
271 | struct dca_provider *dca; | |
272 | int alloc_size; | |
273 | ||
274 | alloc_size = (sizeof(*dca) + priv_size); | |
275 | dca = kzalloc(alloc_size, GFP_KERNEL); | |
276 | if (!dca) | |
277 | return NULL; | |
278 | dca->ops = ops; | |
279 | ||
280 | return dca; | |
281 | } | |
282 | EXPORT_SYMBOL_GPL(alloc_dca_provider); | |
283 | ||
284 | /** | |
285 | * free_dca_provider - release the dca provider data struct | |
286 | * @ops - pointer to struct of dca operation function pointers | |
287 | * @priv_size - size of extra mem to be added for provider's needs | |
288 | */ | |
289 | void free_dca_provider(struct dca_provider *dca) | |
290 | { | |
291 | kfree(dca); | |
292 | } | |
293 | EXPORT_SYMBOL_GPL(free_dca_provider); | |
294 | ||
295 | static BLOCKING_NOTIFIER_HEAD(dca_provider_chain); | |
296 | ||
297 | /** | |
298 | * register_dca_provider - register a dca provider | |
299 | * @dca - struct created by alloc_dca_provider() | |
300 | * @dev - device providing dca services | |
301 | */ | |
302 | int register_dca_provider(struct dca_provider *dca, struct device *dev) | |
303 | { | |
304 | int err; | |
eb4400e3 | 305 | unsigned long flags; |
1a5aeeec | 306 | struct dca_domain *domain; |
7589670f | 307 | |
7589670f SN |
308 | err = dca_sysfs_add_provider(dca, dev); |
309 | if (err) | |
310 | return err; | |
eb4400e3 MS |
311 | |
312 | spin_lock_irqsave(&dca_lock, flags); | |
1a5aeeec MS |
313 | domain = dca_get_domain(dev); |
314 | if (!domain) { | |
315 | spin_unlock_irqrestore(&dca_lock, flags); | |
316 | return -ENODEV; | |
317 | } | |
318 | list_add(&dca->node, &domain->dca_providers); | |
eb4400e3 MS |
319 | spin_unlock_irqrestore(&dca_lock, flags); |
320 | ||
7589670f SN |
321 | blocking_notifier_call_chain(&dca_provider_chain, |
322 | DCA_PROVIDER_ADD, NULL); | |
323 | return 0; | |
324 | } | |
325 | EXPORT_SYMBOL_GPL(register_dca_provider); | |
326 | ||
327 | /** | |
328 | * unregister_dca_provider - remove a dca provider | |
329 | * @dca - struct created by alloc_dca_provider() | |
330 | */ | |
1a5aeeec | 331 | void unregister_dca_provider(struct dca_provider *dca, struct device *dev) |
7589670f | 332 | { |
eb4400e3 | 333 | unsigned long flags; |
1a5aeeec MS |
334 | struct pci_bus *pci_rc; |
335 | struct dca_domain *domain; | |
eb4400e3 | 336 | |
7589670f SN |
337 | blocking_notifier_call_chain(&dca_provider_chain, |
338 | DCA_PROVIDER_REMOVE, NULL); | |
eb4400e3 MS |
339 | |
340 | spin_lock_irqsave(&dca_lock, flags); | |
1a5aeeec | 341 | |
7f1b358a | 342 | list_del(&dca->node); |
1a5aeeec MS |
343 | |
344 | pci_rc = dca_pci_rc_from_dev(dev); | |
345 | domain = dca_find_domain(pci_rc); | |
346 | if (list_empty(&domain->dca_providers)) | |
347 | dca_free_domain(domain); | |
348 | ||
eb4400e3 MS |
349 | spin_unlock_irqrestore(&dca_lock, flags); |
350 | ||
7589670f SN |
351 | dca_sysfs_remove_provider(dca); |
352 | } | |
353 | EXPORT_SYMBOL_GPL(unregister_dca_provider); | |
354 | ||
355 | /** | |
356 | * dca_register_notify - register a client's notifier callback | |
357 | */ | |
358 | void dca_register_notify(struct notifier_block *nb) | |
359 | { | |
360 | blocking_notifier_chain_register(&dca_provider_chain, nb); | |
361 | } | |
362 | EXPORT_SYMBOL_GPL(dca_register_notify); | |
363 | ||
364 | /** | |
365 | * dca_unregister_notify - remove a client's notifier callback | |
366 | */ | |
367 | void dca_unregister_notify(struct notifier_block *nb) | |
368 | { | |
369 | blocking_notifier_chain_unregister(&dca_provider_chain, nb); | |
370 | } | |
371 | EXPORT_SYMBOL_GPL(dca_unregister_notify); | |
372 | ||
373 | static int __init dca_init(void) | |
374 | { | |
7f1b358a | 375 | printk(KERN_ERR "dca service started, version %s\n", DCA_VERSION); |
7589670f SN |
376 | return dca_sysfs_init(); |
377 | } | |
378 | ||
379 | static void __exit dca_exit(void) | |
380 | { | |
381 | dca_sysfs_exit(); | |
382 | } | |
383 | ||
652afc27 | 384 | arch_initcall(dca_init); |
7589670f SN |
385 | module_exit(dca_exit); |
386 |