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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 */ | |
17 | #define HWLOCK_IRQSTATE 0x01 /* Disable interrupts, save state */ | |
18 | #define HWLOCK_IRQ 0x02 /* Disable interrupts, don't save state */ | |
1e6c06a7 | 19 | #define HWLOCK_RAW 0x03 |
bd9a4c7d | 20 | |
313162d0 | 21 | struct device; |
fb7737e9 | 22 | struct device_node; |
bd9a4c7d | 23 | struct hwspinlock; |
300bab97 OBC |
24 | struct hwspinlock_device; |
25 | struct hwspinlock_ops; | |
bd9a4c7d | 26 | |
c3c1250e OBC |
27 | /** |
28 | * struct hwspinlock_pdata - platform data for hwspinlock drivers | |
29 | * @base_id: base id for this hwspinlock device | |
30 | * | |
31 | * hwspinlock devices provide system-wide hardware locks that are used | |
32 | * by remote processors that have no other way to achieve synchronization. | |
33 | * | |
34 | * To achieve that, each physical lock must have a system-wide id number | |
35 | * that is agreed upon, otherwise remote processors can't possibly assume | |
36 | * they're using the same hardware lock. | |
37 | * | |
38 | * Usually boards have a single hwspinlock device, which provides several | |
39 | * hwspinlocks, and in this case, they can be trivially numbered 0 to | |
40 | * (num-of-locks - 1). | |
41 | * | |
42 | * In case boards have several hwspinlocks devices, a different base id | |
43 | * should be used for each hwspinlock device (they can't all use 0 as | |
44 | * a starting id!). | |
45 | * | |
46 | * This platform data structure should be used to provide the base id | |
47 | * for each device (which is trivially 0 when only a single hwspinlock | |
48 | * device exists). It can be shared between different platforms, hence | |
49 | * its location. | |
50 | */ | |
51 | struct hwspinlock_pdata { | |
52 | int base_id; | |
53 | }; | |
54 | ||
bd9a4c7d OBC |
55 | #if defined(CONFIG_HWSPINLOCK) || defined(CONFIG_HWSPINLOCK_MODULE) |
56 | ||
300bab97 OBC |
57 | int hwspin_lock_register(struct hwspinlock_device *bank, struct device *dev, |
58 | const struct hwspinlock_ops *ops, int base_id, int num_locks); | |
59 | int hwspin_lock_unregister(struct hwspinlock_device *bank); | |
bd9a4c7d OBC |
60 | struct hwspinlock *hwspin_lock_request(void); |
61 | struct hwspinlock *hwspin_lock_request_specific(unsigned int id); | |
62 | int hwspin_lock_free(struct hwspinlock *hwlock); | |
fb7737e9 | 63 | int of_hwspin_lock_get_id(struct device_node *np, int index); |
bd9a4c7d OBC |
64 | int hwspin_lock_get_id(struct hwspinlock *hwlock); |
65 | int __hwspin_lock_timeout(struct hwspinlock *, unsigned int, int, | |
66 | unsigned long *); | |
67 | int __hwspin_trylock(struct hwspinlock *, int, unsigned long *); | |
68 | void __hwspin_unlock(struct hwspinlock *, int, unsigned long *); | |
69 | ||
70 | #else /* !CONFIG_HWSPINLOCK */ | |
71 | ||
72 | /* | |
73 | * We don't want these functions to fail if CONFIG_HWSPINLOCK is not | |
74 | * enabled. We prefer to silently succeed in this case, and let the | |
75 | * code path get compiled away. This way, if CONFIG_HWSPINLOCK is not | |
76 | * required on a given setup, users will still work. | |
77 | * | |
78 | * The only exception is hwspin_lock_register/hwspin_lock_unregister, with which | |
79 | * we _do_ want users to fail (no point in registering hwspinlock instances if | |
80 | * the framework is not available). | |
81 | * | |
82 | * Note: ERR_PTR(-ENODEV) will still be considered a success for NULL-checking | |
83 | * users. Others, which care, can still check this with IS_ERR. | |
84 | */ | |
85 | static inline struct hwspinlock *hwspin_lock_request(void) | |
86 | { | |
87 | return ERR_PTR(-ENODEV); | |
88 | } | |
89 | ||
90 | static inline struct hwspinlock *hwspin_lock_request_specific(unsigned int id) | |
91 | { | |
92 | return ERR_PTR(-ENODEV); | |
93 | } | |
94 | ||
95 | static inline int hwspin_lock_free(struct hwspinlock *hwlock) | |
96 | { | |
97 | return 0; | |
98 | } | |
99 | ||
100 | static inline | |
101 | int __hwspin_lock_timeout(struct hwspinlock *hwlock, unsigned int to, | |
102 | int mode, unsigned long *flags) | |
103 | { | |
104 | return 0; | |
105 | } | |
106 | ||
107 | static inline | |
108 | int __hwspin_trylock(struct hwspinlock *hwlock, int mode, unsigned long *flags) | |
109 | { | |
110 | return 0; | |
111 | } | |
112 | ||
113 | static inline | |
114 | void __hwspin_unlock(struct hwspinlock *hwlock, int mode, unsigned long *flags) | |
115 | { | |
bd9a4c7d OBC |
116 | } |
117 | ||
fb7737e9 SA |
118 | static inline int of_hwspin_lock_get_id(struct device_node *np, int index) |
119 | { | |
120 | return 0; | |
121 | } | |
122 | ||
bd9a4c7d OBC |
123 | static inline int hwspin_lock_get_id(struct hwspinlock *hwlock) |
124 | { | |
125 | return 0; | |
126 | } | |
127 | ||
bd9a4c7d OBC |
128 | #endif /* !CONFIG_HWSPINLOCK */ |
129 | ||
130 | /** | |
131 | * hwspin_trylock_irqsave() - try to lock an hwspinlock, disable interrupts | |
132 | * @hwlock: an hwspinlock which we want to trylock | |
133 | * @flags: a pointer to where the caller's interrupt state will be saved at | |
134 | * | |
135 | * This function attempts to lock the underlying hwspinlock, and will | |
136 | * immediately fail if the hwspinlock is already locked. | |
137 | * | |
138 | * Upon a successful return from this function, preemption and local | |
139 | * interrupts are disabled (previous interrupts state is saved at @flags), | |
140 | * so the caller must not sleep, and is advised to release the hwspinlock | |
141 | * as soon as possible. | |
142 | * | |
143 | * Returns 0 if we successfully locked the hwspinlock, -EBUSY if | |
144 | * the hwspinlock was already taken, and -EINVAL if @hwlock is invalid. | |
145 | */ | |
146 | static inline | |
147 | int hwspin_trylock_irqsave(struct hwspinlock *hwlock, unsigned long *flags) | |
148 | { | |
149 | return __hwspin_trylock(hwlock, HWLOCK_IRQSTATE, flags); | |
150 | } | |
151 | ||
152 | /** | |
153 | * hwspin_trylock_irq() - try to lock an hwspinlock, disable interrupts | |
154 | * @hwlock: an hwspinlock which we want to trylock | |
155 | * | |
156 | * This function attempts to lock the underlying hwspinlock, and will | |
157 | * immediately fail if the hwspinlock is already locked. | |
158 | * | |
159 | * Upon a successful return from this function, preemption and local | |
160 | * interrupts are disabled, so the caller must not sleep, and is advised | |
161 | * to release the hwspinlock as soon as possible. | |
162 | * | |
163 | * Returns 0 if we successfully locked the hwspinlock, -EBUSY if | |
164 | * the hwspinlock was already taken, and -EINVAL if @hwlock is invalid. | |
165 | */ | |
166 | static inline int hwspin_trylock_irq(struct hwspinlock *hwlock) | |
167 | { | |
168 | return __hwspin_trylock(hwlock, HWLOCK_IRQ, NULL); | |
169 | } | |
170 | ||
1e6c06a7 BW |
171 | /** |
172 | * hwspin_trylock_raw() - attempt to lock a specific hwspinlock | |
173 | * @hwlock: an hwspinlock which we want to trylock | |
174 | * | |
175 | * This function attempts to lock an hwspinlock, and will immediately fail | |
176 | * if the hwspinlock is already taken. | |
177 | * | |
178 | * Caution: User must protect the routine of getting hardware lock with mutex | |
179 | * or spinlock to avoid dead-lock, that will let user can do some time-consuming | |
180 | * or sleepable operations under the hardware lock. | |
181 | * | |
182 | * Returns 0 if we successfully locked the hwspinlock, -EBUSY if | |
183 | * the hwspinlock was already taken, and -EINVAL if @hwlock is invalid. | |
184 | */ | |
185 | static inline int hwspin_trylock_raw(struct hwspinlock *hwlock) | |
186 | { | |
187 | return __hwspin_trylock(hwlock, HWLOCK_RAW, NULL); | |
188 | } | |
189 | ||
bd9a4c7d OBC |
190 | /** |
191 | * hwspin_trylock() - attempt to lock a specific hwspinlock | |
192 | * @hwlock: an hwspinlock which we want to trylock | |
193 | * | |
194 | * This function attempts to lock an hwspinlock, and will immediately fail | |
195 | * if the hwspinlock is already taken. | |
196 | * | |
197 | * Upon a successful return from this function, preemption is disabled, | |
198 | * so the caller must not sleep, and is advised to release the hwspinlock | |
199 | * as soon as possible. This is required in order to minimize remote cores | |
200 | * polling on the hardware interconnect. | |
201 | * | |
202 | * Returns 0 if we successfully locked the hwspinlock, -EBUSY if | |
203 | * the hwspinlock was already taken, and -EINVAL if @hwlock is invalid. | |
204 | */ | |
205 | static inline int hwspin_trylock(struct hwspinlock *hwlock) | |
206 | { | |
207 | return __hwspin_trylock(hwlock, 0, NULL); | |
208 | } | |
209 | ||
210 | /** | |
211 | * hwspin_lock_timeout_irqsave() - lock hwspinlock, with timeout, disable irqs | |
212 | * @hwlock: the hwspinlock to be locked | |
213 | * @to: timeout value in msecs | |
214 | * @flags: a pointer to where the caller's interrupt state will be saved at | |
215 | * | |
216 | * This function locks the underlying @hwlock. If the @hwlock | |
217 | * is already taken, the function will busy loop waiting for it to | |
218 | * be released, but give up when @timeout msecs have elapsed. | |
219 | * | |
220 | * Upon a successful return from this function, preemption and local interrupts | |
221 | * are disabled (plus previous interrupt state is saved), so the caller must | |
222 | * not sleep, and is advised to release the hwspinlock as soon as possible. | |
223 | * | |
224 | * Returns 0 when the @hwlock was successfully taken, and an appropriate | |
225 | * error code otherwise (most notably an -ETIMEDOUT if the @hwlock is still | |
226 | * busy after @timeout msecs). The function will never sleep. | |
227 | */ | |
228 | static inline int hwspin_lock_timeout_irqsave(struct hwspinlock *hwlock, | |
229 | unsigned int to, unsigned long *flags) | |
230 | { | |
231 | return __hwspin_lock_timeout(hwlock, to, HWLOCK_IRQSTATE, flags); | |
232 | } | |
233 | ||
234 | /** | |
235 | * hwspin_lock_timeout_irq() - lock hwspinlock, with timeout, disable irqs | |
236 | * @hwlock: the hwspinlock to be locked | |
237 | * @to: timeout value in msecs | |
238 | * | |
239 | * This function locks the underlying @hwlock. If the @hwlock | |
240 | * is already taken, the function will busy loop waiting for it to | |
241 | * be released, but give up when @timeout msecs have elapsed. | |
242 | * | |
243 | * Upon a successful return from this function, preemption and local interrupts | |
244 | * are disabled so the caller must not sleep, and is advised to release the | |
245 | * hwspinlock as soon as possible. | |
246 | * | |
247 | * Returns 0 when the @hwlock was successfully taken, and an appropriate | |
248 | * error code otherwise (most notably an -ETIMEDOUT if the @hwlock is still | |
249 | * busy after @timeout msecs). The function will never sleep. | |
250 | */ | |
251 | static inline | |
252 | int hwspin_lock_timeout_irq(struct hwspinlock *hwlock, unsigned int to) | |
253 | { | |
254 | return __hwspin_lock_timeout(hwlock, to, HWLOCK_IRQ, NULL); | |
255 | } | |
256 | ||
1e6c06a7 BW |
257 | /** |
258 | * hwspin_lock_timeout_raw() - lock an hwspinlock with timeout limit | |
259 | * @hwlock: the hwspinlock to be locked | |
260 | * @to: timeout value in msecs | |
261 | * | |
262 | * This function locks the underlying @hwlock. If the @hwlock | |
263 | * is already taken, the function will busy loop waiting for it to | |
264 | * be released, but give up when @timeout msecs have elapsed. | |
265 | * | |
266 | * Caution: User must protect the routine of getting hardware lock with mutex | |
267 | * or spinlock to avoid dead-lock, that will let user can do some time-consuming | |
268 | * or sleepable operations under the hardware lock. | |
269 | * | |
270 | * Returns 0 when the @hwlock was successfully taken, and an appropriate | |
271 | * error code otherwise (most notably an -ETIMEDOUT if the @hwlock is still | |
272 | * busy after @timeout msecs). The function will never sleep. | |
273 | */ | |
274 | static inline | |
275 | int hwspin_lock_timeout_raw(struct hwspinlock *hwlock, unsigned int to) | |
276 | { | |
277 | return __hwspin_lock_timeout(hwlock, to, HWLOCK_RAW, NULL); | |
278 | } | |
279 | ||
bd9a4c7d OBC |
280 | /** |
281 | * hwspin_lock_timeout() - lock an hwspinlock with timeout limit | |
282 | * @hwlock: the hwspinlock to be locked | |
283 | * @to: timeout value in msecs | |
284 | * | |
285 | * This function locks the underlying @hwlock. If the @hwlock | |
286 | * is already taken, the function will busy loop waiting for it to | |
287 | * be released, but give up when @timeout msecs have elapsed. | |
288 | * | |
289 | * Upon a successful return from this function, preemption is disabled | |
290 | * so the caller must not sleep, and is advised to release the hwspinlock | |
291 | * as soon as possible. | |
292 | * This is required in order to minimize remote cores polling on the | |
293 | * hardware interconnect. | |
294 | * | |
295 | * Returns 0 when the @hwlock was successfully taken, and an appropriate | |
296 | * error code otherwise (most notably an -ETIMEDOUT if the @hwlock is still | |
297 | * busy after @timeout msecs). The function will never sleep. | |
298 | */ | |
299 | static inline | |
300 | int hwspin_lock_timeout(struct hwspinlock *hwlock, unsigned int to) | |
301 | { | |
302 | return __hwspin_lock_timeout(hwlock, to, 0, NULL); | |
303 | } | |
304 | ||
305 | /** | |
306 | * hwspin_unlock_irqrestore() - unlock hwspinlock, restore irq state | |
307 | * @hwlock: a previously-acquired hwspinlock which we want to unlock | |
308 | * @flags: previous caller's interrupt state to restore | |
309 | * | |
310 | * This function will unlock a specific hwspinlock, enable preemption and | |
311 | * restore the previous state of the local interrupts. It should be used | |
312 | * to undo, e.g., hwspin_trylock_irqsave(). | |
313 | * | |
314 | * @hwlock must be already locked before calling this function: it is a bug | |
315 | * to call unlock on a @hwlock that is already unlocked. | |
316 | */ | |
317 | static inline void hwspin_unlock_irqrestore(struct hwspinlock *hwlock, | |
318 | unsigned long *flags) | |
319 | { | |
320 | __hwspin_unlock(hwlock, HWLOCK_IRQSTATE, flags); | |
321 | } | |
322 | ||
323 | /** | |
324 | * hwspin_unlock_irq() - unlock hwspinlock, enable interrupts | |
325 | * @hwlock: a previously-acquired hwspinlock which we want to unlock | |
326 | * | |
327 | * This function will unlock a specific hwspinlock, enable preemption and | |
328 | * enable local interrupts. Should be used to undo hwspin_lock_irq(). | |
329 | * | |
330 | * @hwlock must be already locked (e.g. by hwspin_trylock_irq()) before | |
331 | * calling this function: it is a bug to call unlock on a @hwlock that is | |
332 | * already unlocked. | |
333 | */ | |
334 | static inline void hwspin_unlock_irq(struct hwspinlock *hwlock) | |
335 | { | |
336 | __hwspin_unlock(hwlock, HWLOCK_IRQ, NULL); | |
337 | } | |
338 | ||
1e6c06a7 BW |
339 | /** |
340 | * hwspin_unlock_raw() - unlock hwspinlock | |
341 | * @hwlock: a previously-acquired hwspinlock which we want to unlock | |
342 | * | |
343 | * This function will unlock a specific hwspinlock. | |
344 | * | |
345 | * @hwlock must be already locked (e.g. by hwspin_trylock()) before calling | |
346 | * this function: it is a bug to call unlock on a @hwlock that is already | |
347 | * unlocked. | |
348 | */ | |
349 | static inline void hwspin_unlock_raw(struct hwspinlock *hwlock) | |
350 | { | |
351 | __hwspin_unlock(hwlock, HWLOCK_RAW, NULL); | |
352 | } | |
353 | ||
bd9a4c7d OBC |
354 | /** |
355 | * hwspin_unlock() - unlock hwspinlock | |
356 | * @hwlock: a previously-acquired hwspinlock which we want to unlock | |
357 | * | |
358 | * This function will unlock a specific hwspinlock and enable preemption | |
359 | * back. | |
360 | * | |
361 | * @hwlock must be already locked (e.g. by hwspin_trylock()) before calling | |
362 | * this function: it is a bug to call unlock on a @hwlock that is already | |
363 | * unlocked. | |
364 | */ | |
365 | static inline void hwspin_unlock(struct hwspinlock *hwlock) | |
366 | { | |
367 | __hwspin_unlock(hwlock, 0, NULL); | |
368 | } | |
369 | ||
370 | #endif /* __LINUX_HWSPINLOCK_H */ |