Commit | Line | Data |
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eebba71e | 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
bd9a4c7d OBC |
2 | /* |
3 | * Hardware spinlock public header | |
4 | * | |
5 | * Copyright (C) 2010 Texas Instruments Incorporated - http://www.ti.com | |
6 | * | |
7 | * Contact: Ohad Ben-Cohen <ohad@wizery.com> | |
bd9a4c7d OBC |
8 | */ |
9 | ||
10 | #ifndef __LINUX_HWSPINLOCK_H | |
11 | #define __LINUX_HWSPINLOCK_H | |
12 | ||
13 | #include <linux/err.h> | |
14 | #include <linux/sched.h> | |
15 | ||
16 | /* hwspinlock mode argument */ | |
360aa640 FD |
17 | #define HWLOCK_IRQSTATE 0x01 /* Disable interrupts, save state */ |
18 | #define HWLOCK_IRQ 0x02 /* Disable interrupts, don't save state */ | |
19 | #define HWLOCK_RAW 0x03 | |
20 | #define HWLOCK_IN_ATOMIC 0x04 /* Called while in atomic context */ | |
bd9a4c7d | 21 | |
313162d0 | 22 | struct device; |
fb7737e9 | 23 | struct device_node; |
bd9a4c7d | 24 | struct hwspinlock; |
300bab97 OBC |
25 | struct hwspinlock_device; |
26 | struct hwspinlock_ops; | |
bd9a4c7d | 27 | |
c3c1250e OBC |
28 | /** |
29 | * struct hwspinlock_pdata - platform data for hwspinlock drivers | |
30 | * @base_id: base id for this hwspinlock device | |
31 | * | |
32 | * hwspinlock devices provide system-wide hardware locks that are used | |
33 | * by remote processors that have no other way to achieve synchronization. | |
34 | * | |
35 | * To achieve that, each physical lock must have a system-wide id number | |
36 | * that is agreed upon, otherwise remote processors can't possibly assume | |
37 | * they're using the same hardware lock. | |
38 | * | |
39 | * Usually boards have a single hwspinlock device, which provides several | |
40 | * hwspinlocks, and in this case, they can be trivially numbered 0 to | |
41 | * (num-of-locks - 1). | |
42 | * | |
43 | * In case boards have several hwspinlocks devices, a different base id | |
44 | * should be used for each hwspinlock device (they can't all use 0 as | |
45 | * a starting id!). | |
46 | * | |
47 | * This platform data structure should be used to provide the base id | |
48 | * for each device (which is trivially 0 when only a single hwspinlock | |
49 | * device exists). It can be shared between different platforms, hence | |
50 | * its location. | |
51 | */ | |
52 | struct hwspinlock_pdata { | |
53 | int base_id; | |
54 | }; | |
55 | ||
2ceda54c | 56 | #ifdef CONFIG_HWSPINLOCK |
bd9a4c7d | 57 | |
300bab97 OBC |
58 | int hwspin_lock_register(struct hwspinlock_device *bank, struct device *dev, |
59 | const struct hwspinlock_ops *ops, int base_id, int num_locks); | |
60 | int hwspin_lock_unregister(struct hwspinlock_device *bank); | |
bd9a4c7d OBC |
61 | struct hwspinlock *hwspin_lock_request(void); |
62 | struct hwspinlock *hwspin_lock_request_specific(unsigned int id); | |
63 | int hwspin_lock_free(struct hwspinlock *hwlock); | |
fb7737e9 | 64 | int of_hwspin_lock_get_id(struct device_node *np, int index); |
bd9a4c7d OBC |
65 | int hwspin_lock_get_id(struct hwspinlock *hwlock); |
66 | int __hwspin_lock_timeout(struct hwspinlock *, unsigned int, int, | |
67 | unsigned long *); | |
68 | int __hwspin_trylock(struct hwspinlock *, int, unsigned long *); | |
69 | void __hwspin_unlock(struct hwspinlock *, int, unsigned long *); | |
5560f70c | 70 | int of_hwspin_lock_get_id_byname(struct device_node *np, const char *name); |
4f1acd75 BW |
71 | int devm_hwspin_lock_free(struct device *dev, struct hwspinlock *hwlock); |
72 | struct hwspinlock *devm_hwspin_lock_request(struct device *dev); | |
73 | struct hwspinlock *devm_hwspin_lock_request_specific(struct device *dev, | |
74 | unsigned int id); | |
c102780a BW |
75 | int devm_hwspin_lock_unregister(struct device *dev, |
76 | struct hwspinlock_device *bank); | |
77 | int devm_hwspin_lock_register(struct device *dev, | |
78 | struct hwspinlock_device *bank, | |
79 | const struct hwspinlock_ops *ops, | |
80 | int base_id, int num_locks); | |
bd9a4c7d OBC |
81 | |
82 | #else /* !CONFIG_HWSPINLOCK */ | |
83 | ||
84 | /* | |
85 | * We don't want these functions to fail if CONFIG_HWSPINLOCK is not | |
86 | * enabled. We prefer to silently succeed in this case, and let the | |
87 | * code path get compiled away. This way, if CONFIG_HWSPINLOCK is not | |
88 | * required on a given setup, users will still work. | |
89 | * | |
90 | * The only exception is hwspin_lock_register/hwspin_lock_unregister, with which | |
91 | * we _do_ want users to fail (no point in registering hwspinlock instances if | |
92 | * the framework is not available). | |
93 | * | |
94 | * Note: ERR_PTR(-ENODEV) will still be considered a success for NULL-checking | |
95 | * users. Others, which care, can still check this with IS_ERR. | |
96 | */ | |
97 | static inline struct hwspinlock *hwspin_lock_request(void) | |
98 | { | |
99 | return ERR_PTR(-ENODEV); | |
100 | } | |
101 | ||
102 | static inline struct hwspinlock *hwspin_lock_request_specific(unsigned int id) | |
103 | { | |
104 | return ERR_PTR(-ENODEV); | |
105 | } | |
106 | ||
107 | static inline int hwspin_lock_free(struct hwspinlock *hwlock) | |
108 | { | |
109 | return 0; | |
110 | } | |
111 | ||
112 | static inline | |
113 | int __hwspin_lock_timeout(struct hwspinlock *hwlock, unsigned int to, | |
114 | int mode, unsigned long *flags) | |
115 | { | |
116 | return 0; | |
117 | } | |
118 | ||
119 | static inline | |
120 | int __hwspin_trylock(struct hwspinlock *hwlock, int mode, unsigned long *flags) | |
121 | { | |
122 | return 0; | |
123 | } | |
124 | ||
125 | static inline | |
126 | void __hwspin_unlock(struct hwspinlock *hwlock, int mode, unsigned long *flags) | |
127 | { | |
bd9a4c7d OBC |
128 | } |
129 | ||
fb7737e9 SA |
130 | static inline int of_hwspin_lock_get_id(struct device_node *np, int index) |
131 | { | |
132 | return 0; | |
133 | } | |
134 | ||
bd9a4c7d OBC |
135 | static inline int hwspin_lock_get_id(struct hwspinlock *hwlock) |
136 | { | |
137 | return 0; | |
138 | } | |
139 | ||
5560f70c BW |
140 | static inline |
141 | int of_hwspin_lock_get_id_byname(struct device_node *np, const char *name) | |
142 | { | |
143 | return 0; | |
144 | } | |
145 | ||
4f1acd75 BW |
146 | static inline |
147 | int devm_hwspin_lock_free(struct device *dev, struct hwspinlock *hwlock) | |
148 | { | |
149 | return 0; | |
150 | } | |
151 | ||
152 | static inline struct hwspinlock *devm_hwspin_lock_request(struct device *dev) | |
153 | { | |
154 | return ERR_PTR(-ENODEV); | |
155 | } | |
156 | ||
157 | static inline | |
158 | struct hwspinlock *devm_hwspin_lock_request_specific(struct device *dev, | |
159 | unsigned int id) | |
160 | { | |
161 | return ERR_PTR(-ENODEV); | |
162 | } | |
163 | ||
bd9a4c7d OBC |
164 | #endif /* !CONFIG_HWSPINLOCK */ |
165 | ||
166 | /** | |
167 | * hwspin_trylock_irqsave() - try to lock an hwspinlock, disable interrupts | |
168 | * @hwlock: an hwspinlock which we want to trylock | |
169 | * @flags: a pointer to where the caller's interrupt state will be saved at | |
170 | * | |
171 | * This function attempts to lock the underlying hwspinlock, and will | |
172 | * immediately fail if the hwspinlock is already locked. | |
173 | * | |
174 | * Upon a successful return from this function, preemption and local | |
175 | * interrupts are disabled (previous interrupts state is saved at @flags), | |
176 | * so the caller must not sleep, and is advised to release the hwspinlock | |
177 | * as soon as possible. | |
178 | * | |
179 | * Returns 0 if we successfully locked the hwspinlock, -EBUSY if | |
180 | * the hwspinlock was already taken, and -EINVAL if @hwlock is invalid. | |
181 | */ | |
182 | static inline | |
183 | int hwspin_trylock_irqsave(struct hwspinlock *hwlock, unsigned long *flags) | |
184 | { | |
185 | return __hwspin_trylock(hwlock, HWLOCK_IRQSTATE, flags); | |
186 | } | |
187 | ||
188 | /** | |
189 | * hwspin_trylock_irq() - try to lock an hwspinlock, disable interrupts | |
190 | * @hwlock: an hwspinlock which we want to trylock | |
191 | * | |
192 | * This function attempts to lock the underlying hwspinlock, and will | |
193 | * immediately fail if the hwspinlock is already locked. | |
194 | * | |
195 | * Upon a successful return from this function, preemption and local | |
196 | * interrupts are disabled, so the caller must not sleep, and is advised | |
197 | * to release the hwspinlock as soon as possible. | |
198 | * | |
199 | * Returns 0 if we successfully locked the hwspinlock, -EBUSY if | |
200 | * the hwspinlock was already taken, and -EINVAL if @hwlock is invalid. | |
201 | */ | |
202 | static inline int hwspin_trylock_irq(struct hwspinlock *hwlock) | |
203 | { | |
204 | return __hwspin_trylock(hwlock, HWLOCK_IRQ, NULL); | |
205 | } | |
206 | ||
1e6c06a7 BW |
207 | /** |
208 | * hwspin_trylock_raw() - attempt to lock a specific hwspinlock | |
209 | * @hwlock: an hwspinlock which we want to trylock | |
210 | * | |
211 | * This function attempts to lock an hwspinlock, and will immediately fail | |
212 | * if the hwspinlock is already taken. | |
213 | * | |
214 | * Caution: User must protect the routine of getting hardware lock with mutex | |
215 | * or spinlock to avoid dead-lock, that will let user can do some time-consuming | |
216 | * or sleepable operations under the hardware lock. | |
217 | * | |
218 | * Returns 0 if we successfully locked the hwspinlock, -EBUSY if | |
219 | * the hwspinlock was already taken, and -EINVAL if @hwlock is invalid. | |
220 | */ | |
221 | static inline int hwspin_trylock_raw(struct hwspinlock *hwlock) | |
222 | { | |
223 | return __hwspin_trylock(hwlock, HWLOCK_RAW, NULL); | |
224 | } | |
225 | ||
360aa640 FD |
226 | /** |
227 | * hwspin_trylock_in_atomic() - attempt to lock a specific hwspinlock | |
228 | * @hwlock: an hwspinlock which we want to trylock | |
229 | * | |
230 | * This function attempts to lock an hwspinlock, and will immediately fail | |
231 | * if the hwspinlock is already taken. | |
232 | * | |
233 | * This function shall be called only from an atomic context. | |
234 | * | |
235 | * Returns 0 if we successfully locked the hwspinlock, -EBUSY if | |
236 | * the hwspinlock was already taken, and -EINVAL if @hwlock is invalid. | |
237 | */ | |
238 | static inline int hwspin_trylock_in_atomic(struct hwspinlock *hwlock) | |
239 | { | |
240 | return __hwspin_trylock(hwlock, HWLOCK_IN_ATOMIC, NULL); | |
241 | } | |
242 | ||
bd9a4c7d OBC |
243 | /** |
244 | * hwspin_trylock() - attempt to lock a specific hwspinlock | |
245 | * @hwlock: an hwspinlock which we want to trylock | |
246 | * | |
247 | * This function attempts to lock an hwspinlock, and will immediately fail | |
248 | * if the hwspinlock is already taken. | |
249 | * | |
250 | * Upon a successful return from this function, preemption is disabled, | |
251 | * so the caller must not sleep, and is advised to release the hwspinlock | |
252 | * as soon as possible. This is required in order to minimize remote cores | |
253 | * polling on the hardware interconnect. | |
254 | * | |
255 | * Returns 0 if we successfully locked the hwspinlock, -EBUSY if | |
256 | * the hwspinlock was already taken, and -EINVAL if @hwlock is invalid. | |
257 | */ | |
258 | static inline int hwspin_trylock(struct hwspinlock *hwlock) | |
259 | { | |
260 | return __hwspin_trylock(hwlock, 0, NULL); | |
261 | } | |
262 | ||
263 | /** | |
264 | * hwspin_lock_timeout_irqsave() - lock hwspinlock, with timeout, disable irqs | |
265 | * @hwlock: the hwspinlock to be locked | |
266 | * @to: timeout value in msecs | |
267 | * @flags: a pointer to where the caller's interrupt state will be saved at | |
268 | * | |
269 | * This function locks the underlying @hwlock. If the @hwlock | |
270 | * is already taken, the function will busy loop waiting for it to | |
271 | * be released, but give up when @timeout msecs have elapsed. | |
272 | * | |
273 | * Upon a successful return from this function, preemption and local interrupts | |
274 | * are disabled (plus previous interrupt state is saved), so the caller must | |
275 | * not sleep, and is advised to release the hwspinlock as soon as possible. | |
276 | * | |
277 | * Returns 0 when the @hwlock was successfully taken, and an appropriate | |
278 | * error code otherwise (most notably an -ETIMEDOUT if the @hwlock is still | |
279 | * busy after @timeout msecs). The function will never sleep. | |
280 | */ | |
281 | static inline int hwspin_lock_timeout_irqsave(struct hwspinlock *hwlock, | |
282 | unsigned int to, unsigned long *flags) | |
283 | { | |
284 | return __hwspin_lock_timeout(hwlock, to, HWLOCK_IRQSTATE, flags); | |
285 | } | |
286 | ||
287 | /** | |
288 | * hwspin_lock_timeout_irq() - lock hwspinlock, with timeout, disable irqs | |
289 | * @hwlock: the hwspinlock to be locked | |
290 | * @to: timeout value in msecs | |
291 | * | |
292 | * This function locks the underlying @hwlock. If the @hwlock | |
293 | * is already taken, the function will busy loop waiting for it to | |
294 | * be released, but give up when @timeout msecs have elapsed. | |
295 | * | |
296 | * Upon a successful return from this function, preemption and local interrupts | |
297 | * are disabled so the caller must not sleep, and is advised to release the | |
298 | * hwspinlock as soon as possible. | |
299 | * | |
300 | * Returns 0 when the @hwlock was successfully taken, and an appropriate | |
301 | * error code otherwise (most notably an -ETIMEDOUT if the @hwlock is still | |
302 | * busy after @timeout msecs). The function will never sleep. | |
303 | */ | |
304 | static inline | |
305 | int hwspin_lock_timeout_irq(struct hwspinlock *hwlock, unsigned int to) | |
306 | { | |
307 | return __hwspin_lock_timeout(hwlock, to, HWLOCK_IRQ, NULL); | |
308 | } | |
309 | ||
1e6c06a7 BW |
310 | /** |
311 | * hwspin_lock_timeout_raw() - lock an hwspinlock with timeout limit | |
312 | * @hwlock: the hwspinlock to be locked | |
313 | * @to: timeout value in msecs | |
314 | * | |
315 | * This function locks the underlying @hwlock. If the @hwlock | |
316 | * is already taken, the function will busy loop waiting for it to | |
317 | * be released, but give up when @timeout msecs have elapsed. | |
318 | * | |
319 | * Caution: User must protect the routine of getting hardware lock with mutex | |
320 | * or spinlock to avoid dead-lock, that will let user can do some time-consuming | |
321 | * or sleepable operations under the hardware lock. | |
322 | * | |
323 | * Returns 0 when the @hwlock was successfully taken, and an appropriate | |
324 | * error code otherwise (most notably an -ETIMEDOUT if the @hwlock is still | |
325 | * busy after @timeout msecs). The function will never sleep. | |
326 | */ | |
327 | static inline | |
328 | int hwspin_lock_timeout_raw(struct hwspinlock *hwlock, unsigned int to) | |
329 | { | |
330 | return __hwspin_lock_timeout(hwlock, to, HWLOCK_RAW, NULL); | |
331 | } | |
332 | ||
360aa640 FD |
333 | /** |
334 | * hwspin_lock_timeout_in_atomic() - lock an hwspinlock with timeout limit | |
335 | * @hwlock: the hwspinlock to be locked | |
336 | * @to: timeout value in msecs | |
337 | * | |
338 | * This function locks the underlying @hwlock. If the @hwlock | |
339 | * is already taken, the function will busy loop waiting for it to | |
340 | * be released, but give up when @timeout msecs have elapsed. | |
341 | * | |
342 | * This function shall be called only from an atomic context and the timeout | |
343 | * value shall not exceed a few msecs. | |
344 | * | |
345 | * Returns 0 when the @hwlock was successfully taken, and an appropriate | |
346 | * error code otherwise (most notably an -ETIMEDOUT if the @hwlock is still | |
347 | * busy after @timeout msecs). The function will never sleep. | |
348 | */ | |
349 | static inline | |
350 | int hwspin_lock_timeout_in_atomic(struct hwspinlock *hwlock, unsigned int to) | |
351 | { | |
352 | return __hwspin_lock_timeout(hwlock, to, HWLOCK_IN_ATOMIC, NULL); | |
353 | } | |
354 | ||
bd9a4c7d OBC |
355 | /** |
356 | * hwspin_lock_timeout() - lock an hwspinlock with timeout limit | |
357 | * @hwlock: the hwspinlock to be locked | |
358 | * @to: timeout value in msecs | |
359 | * | |
360 | * This function locks the underlying @hwlock. If the @hwlock | |
361 | * is already taken, the function will busy loop waiting for it to | |
362 | * be released, but give up when @timeout msecs have elapsed. | |
363 | * | |
364 | * Upon a successful return from this function, preemption is disabled | |
365 | * so the caller must not sleep, and is advised to release the hwspinlock | |
366 | * as soon as possible. | |
367 | * This is required in order to minimize remote cores polling on the | |
368 | * hardware interconnect. | |
369 | * | |
370 | * Returns 0 when the @hwlock was successfully taken, and an appropriate | |
371 | * error code otherwise (most notably an -ETIMEDOUT if the @hwlock is still | |
372 | * busy after @timeout msecs). The function will never sleep. | |
373 | */ | |
374 | static inline | |
375 | int hwspin_lock_timeout(struct hwspinlock *hwlock, unsigned int to) | |
376 | { | |
377 | return __hwspin_lock_timeout(hwlock, to, 0, NULL); | |
378 | } | |
379 | ||
380 | /** | |
381 | * hwspin_unlock_irqrestore() - unlock hwspinlock, restore irq state | |
382 | * @hwlock: a previously-acquired hwspinlock which we want to unlock | |
383 | * @flags: previous caller's interrupt state to restore | |
384 | * | |
385 | * This function will unlock a specific hwspinlock, enable preemption and | |
386 | * restore the previous state of the local interrupts. It should be used | |
387 | * to undo, e.g., hwspin_trylock_irqsave(). | |
388 | * | |
389 | * @hwlock must be already locked before calling this function: it is a bug | |
390 | * to call unlock on a @hwlock that is already unlocked. | |
391 | */ | |
392 | static inline void hwspin_unlock_irqrestore(struct hwspinlock *hwlock, | |
393 | unsigned long *flags) | |
394 | { | |
395 | __hwspin_unlock(hwlock, HWLOCK_IRQSTATE, flags); | |
396 | } | |
397 | ||
398 | /** | |
399 | * hwspin_unlock_irq() - unlock hwspinlock, enable interrupts | |
400 | * @hwlock: a previously-acquired hwspinlock which we want to unlock | |
401 | * | |
402 | * This function will unlock a specific hwspinlock, enable preemption and | |
403 | * enable local interrupts. Should be used to undo hwspin_lock_irq(). | |
404 | * | |
405 | * @hwlock must be already locked (e.g. by hwspin_trylock_irq()) before | |
406 | * calling this function: it is a bug to call unlock on a @hwlock that is | |
407 | * already unlocked. | |
408 | */ | |
409 | static inline void hwspin_unlock_irq(struct hwspinlock *hwlock) | |
410 | { | |
411 | __hwspin_unlock(hwlock, HWLOCK_IRQ, NULL); | |
412 | } | |
413 | ||
1e6c06a7 BW |
414 | /** |
415 | * hwspin_unlock_raw() - unlock hwspinlock | |
416 | * @hwlock: a previously-acquired hwspinlock which we want to unlock | |
417 | * | |
418 | * This function will unlock a specific hwspinlock. | |
419 | * | |
420 | * @hwlock must be already locked (e.g. by hwspin_trylock()) before calling | |
421 | * this function: it is a bug to call unlock on a @hwlock that is already | |
422 | * unlocked. | |
423 | */ | |
424 | static inline void hwspin_unlock_raw(struct hwspinlock *hwlock) | |
425 | { | |
426 | __hwspin_unlock(hwlock, HWLOCK_RAW, NULL); | |
427 | } | |
428 | ||
360aa640 FD |
429 | /** |
430 | * hwspin_unlock_in_atomic() - unlock hwspinlock | |
431 | * @hwlock: a previously-acquired hwspinlock which we want to unlock | |
432 | * | |
433 | * This function will unlock a specific hwspinlock. | |
434 | * | |
435 | * @hwlock must be already locked (e.g. by hwspin_trylock()) before calling | |
436 | * this function: it is a bug to call unlock on a @hwlock that is already | |
437 | * unlocked. | |
438 | */ | |
439 | static inline void hwspin_unlock_in_atomic(struct hwspinlock *hwlock) | |
440 | { | |
441 | __hwspin_unlock(hwlock, HWLOCK_IN_ATOMIC, NULL); | |
442 | } | |
443 | ||
bd9a4c7d OBC |
444 | /** |
445 | * hwspin_unlock() - unlock hwspinlock | |
446 | * @hwlock: a previously-acquired hwspinlock which we want to unlock | |
447 | * | |
448 | * This function will unlock a specific hwspinlock and enable preemption | |
449 | * back. | |
450 | * | |
451 | * @hwlock must be already locked (e.g. by hwspin_trylock()) before calling | |
452 | * this function: it is a bug to call unlock on a @hwlock that is already | |
453 | * unlocked. | |
454 | */ | |
455 | static inline void hwspin_unlock(struct hwspinlock *hwlock) | |
456 | { | |
457 | __hwspin_unlock(hwlock, 0, NULL); | |
458 | } | |
459 | ||
460 | #endif /* __LINUX_HWSPINLOCK_H */ |