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1da177e4 | 1 | /* |
45465487 | 2 | * A generic kernel FIFO implementation. |
1da177e4 | 3 | * |
45465487 | 4 | * Copyright (C) 2009 Stefani Seibold <stefani@seibold.net> |
1da177e4 LT |
5 | * Copyright (C) 2004 Stelian Pop <stelian@popies.net> |
6 | * | |
7 | * This program is free software; you can redistribute it and/or modify | |
8 | * it under the terms of the GNU General Public License as published by | |
9 | * the Free Software Foundation; either version 2 of the License, or | |
10 | * (at your option) any later version. | |
11 | * | |
12 | * This program is distributed in the hope that it will be useful, | |
13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
15 | * GNU General Public License for more details. | |
16 | * | |
17 | * You should have received a copy of the GNU General Public License | |
18 | * along with this program; if not, write to the Free Software | |
19 | * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. | |
20 | * | |
21 | */ | |
7acd72eb SS |
22 | |
23 | /* | |
24 | * Howto porting drivers to the new generic fifo API: | |
25 | * | |
26 | * - Modify the declaration of the "struct kfifo *" object into a | |
27 | * in-place "struct kfifo" object | |
28 | * - Init the in-place object with kfifo_alloc() or kfifo_init() | |
29 | * Note: The address of the in-place "struct kfifo" object must be | |
30 | * passed as the first argument to this functions | |
31 | * - Replace the use of __kfifo_put into kfifo_in and __kfifo_get | |
32 | * into kfifo_out | |
33 | * - Replace the use of kfifo_put into kfifo_in_locked and kfifo_get | |
34 | * into kfifo_out_locked | |
35 | * Note: the spinlock pointer formerly passed to kfifo_init/kfifo_alloc | |
36 | * must be passed now to the kfifo_in_locked and kfifo_out_locked | |
37 | * as the last parameter. | |
38 | * - All formerly name __kfifo_* functions has been renamed into kfifo_* | |
39 | */ | |
40 | ||
1da177e4 LT |
41 | #ifndef _LINUX_KFIFO_H |
42 | #define _LINUX_KFIFO_H | |
43 | ||
1da177e4 LT |
44 | #include <linux/kernel.h> |
45 | #include <linux/spinlock.h> | |
46 | ||
47 | struct kfifo { | |
48 | unsigned char *buffer; /* the buffer holding the data */ | |
49 | unsigned int size; /* the size of the allocated buffer */ | |
50 | unsigned int in; /* data is added at offset (in % size) */ | |
51 | unsigned int out; /* data is extracted from off. (out % size) */ | |
1da177e4 LT |
52 | }; |
53 | ||
37bdfbbf SS |
54 | /* |
55 | * Macros for declaration and initialization of the kfifo datatype | |
56 | */ | |
57 | ||
58 | /* helper macro */ | |
59 | #define __kfifo_initializer(s, b) \ | |
60 | (struct kfifo) { \ | |
61 | .size = s, \ | |
62 | .in = 0, \ | |
63 | .out = 0, \ | |
64 | .buffer = b \ | |
65 | } | |
66 | ||
67 | /** | |
68 | * DECLARE_KFIFO - macro to declare a kfifo and the associated buffer | |
69 | * @name: name of the declared kfifo datatype | |
5dab600e | 70 | * @size: size of the fifo buffer. Must be a power of two. |
37bdfbbf | 71 | * |
9c717de9 RD |
72 | * Note1: the macro can be used inside struct or union declaration |
73 | * Note2: the macro creates two objects: | |
37bdfbbf SS |
74 | * A kfifo object with the given name and a buffer for the kfifo |
75 | * object named name##kfifo_buffer | |
76 | */ | |
77 | #define DECLARE_KFIFO(name, size) \ | |
78 | union { \ | |
79 | struct kfifo name; \ | |
80 | unsigned char name##kfifo_buffer[size + sizeof(struct kfifo)]; \ | |
81 | } | |
82 | ||
83 | /** | |
ed656d8d | 84 | * INIT_KFIFO - Initialize a kfifo declared by DECLARE_KFIFO |
37bdfbbf | 85 | * @name: name of the declared kfifo datatype |
37bdfbbf SS |
86 | */ |
87 | #define INIT_KFIFO(name) \ | |
88 | name = __kfifo_initializer(sizeof(name##kfifo_buffer) - \ | |
89 | sizeof(struct kfifo), name##kfifo_buffer) | |
90 | ||
91 | /** | |
92 | * DEFINE_KFIFO - macro to define and initialize a kfifo | |
93 | * @name: name of the declared kfifo datatype | |
5dab600e | 94 | * @size: size of the fifo buffer. Must be a power of two. |
37bdfbbf | 95 | * |
9c717de9 RD |
96 | * Note1: the macro can be used for global and local kfifo data type variables |
97 | * Note2: the macro creates two objects: | |
37bdfbbf SS |
98 | * A kfifo object with the given name and a buffer for the kfifo |
99 | * object named name##kfifo_buffer | |
100 | */ | |
101 | #define DEFINE_KFIFO(name, size) \ | |
102 | unsigned char name##kfifo_buffer[size]; \ | |
103 | struct kfifo name = __kfifo_initializer(size, name##kfifo_buffer) | |
104 | ||
8ecc2951 | 105 | extern void kfifo_init(struct kfifo *fifo, void *buffer, |
c1e13f25 | 106 | unsigned int size); |
45465487 | 107 | extern __must_check int kfifo_alloc(struct kfifo *fifo, unsigned int size, |
c1e13f25 | 108 | gfp_t gfp_mask); |
1da177e4 | 109 | extern void kfifo_free(struct kfifo *fifo); |
9842c38e | 110 | extern unsigned int kfifo_in(struct kfifo *fifo, |
8ecc2951 | 111 | const void *from, unsigned int len); |
7acd72eb | 112 | extern __must_check unsigned int kfifo_out(struct kfifo *fifo, |
8ecc2951 | 113 | void *to, unsigned int len); |
a5b9e2c1 AK |
114 | extern __must_check unsigned int kfifo_out_peek(struct kfifo *fifo, |
115 | void *to, unsigned int len, unsigned offset); | |
116 | ||
d994ffc2 AK |
117 | /** |
118 | * kfifo_initialized - Check if kfifo is initialized. | |
119 | * @fifo: fifo to check | |
120 | * Return %true if FIFO is initialized, otherwise %false. | |
121 | * Assumes the fifo was 0 before. | |
122 | */ | |
123 | static inline bool kfifo_initialized(struct kfifo *fifo) | |
124 | { | |
5a5e0f4c | 125 | return fifo->buffer != NULL; |
d994ffc2 | 126 | } |
1da177e4 | 127 | |
1da177e4 LT |
128 | /** |
129 | * kfifo_reset - removes the entire FIFO contents | |
130 | * @fifo: the fifo to be emptied. | |
131 | */ | |
132 | static inline void kfifo_reset(struct kfifo *fifo) | |
133 | { | |
e64c026d | 134 | fifo->in = fifo->out = 0; |
c1e13f25 SS |
135 | } |
136 | ||
a121f24a SS |
137 | /** |
138 | * kfifo_reset_out - skip FIFO contents | |
139 | * @fifo: the fifo to be emptied. | |
140 | */ | |
141 | static inline void kfifo_reset_out(struct kfifo *fifo) | |
142 | { | |
143 | smp_mb(); | |
144 | fifo->out = fifo->in; | |
145 | } | |
146 | ||
37bdfbbf SS |
147 | /** |
148 | * kfifo_size - returns the size of the fifo in bytes | |
149 | * @fifo: the fifo to be used. | |
150 | */ | |
151 | static inline __must_check unsigned int kfifo_size(struct kfifo *fifo) | |
152 | { | |
153 | return fifo->size; | |
154 | } | |
155 | ||
c1e13f25 | 156 | /** |
e64c026d | 157 | * kfifo_len - returns the number of used bytes in the FIFO |
c1e13f25 SS |
158 | * @fifo: the fifo to be used. |
159 | */ | |
e64c026d | 160 | static inline unsigned int kfifo_len(struct kfifo *fifo) |
c1e13f25 SS |
161 | { |
162 | register unsigned int out; | |
1da177e4 | 163 | |
c1e13f25 SS |
164 | out = fifo->out; |
165 | smp_rmb(); | |
166 | return fifo->in - out; | |
1da177e4 LT |
167 | } |
168 | ||
37bdfbbf SS |
169 | /** |
170 | * kfifo_is_empty - returns true if the fifo is empty | |
171 | * @fifo: the fifo to be used. | |
172 | */ | |
173 | static inline __must_check int kfifo_is_empty(struct kfifo *fifo) | |
174 | { | |
175 | return fifo->in == fifo->out; | |
176 | } | |
177 | ||
178 | /** | |
179 | * kfifo_is_full - returns true if the fifo is full | |
180 | * @fifo: the fifo to be used. | |
181 | */ | |
182 | static inline __must_check int kfifo_is_full(struct kfifo *fifo) | |
183 | { | |
184 | return kfifo_len(fifo) == kfifo_size(fifo); | |
185 | } | |
186 | ||
187 | /** | |
188 | * kfifo_avail - returns the number of bytes available in the FIFO | |
189 | * @fifo: the fifo to be used. | |
190 | */ | |
191 | static inline __must_check unsigned int kfifo_avail(struct kfifo *fifo) | |
192 | { | |
193 | return kfifo_size(fifo) - kfifo_len(fifo); | |
194 | } | |
195 | ||
1da177e4 | 196 | /** |
7acd72eb | 197 | * kfifo_in_locked - puts some data into the FIFO using a spinlock for locking |
1da177e4 | 198 | * @fifo: the fifo to be used. |
c1e13f25 SS |
199 | * @from: the data to be added. |
200 | * @n: the length of the data to be added. | |
201 | * @lock: pointer to the spinlock to use for locking. | |
1da177e4 | 202 | * |
c1e13f25 | 203 | * This function copies at most @len bytes from the @from buffer into |
1da177e4 LT |
204 | * the FIFO depending on the free space, and returns the number of |
205 | * bytes copied. | |
206 | */ | |
9842c38e | 207 | static inline unsigned int kfifo_in_locked(struct kfifo *fifo, |
8ecc2951 | 208 | const void *from, unsigned int n, spinlock_t *lock) |
1da177e4 LT |
209 | { |
210 | unsigned long flags; | |
211 | unsigned int ret; | |
212 | ||
c1e13f25 | 213 | spin_lock_irqsave(lock, flags); |
1da177e4 | 214 | |
7acd72eb | 215 | ret = kfifo_in(fifo, from, n); |
1da177e4 | 216 | |
c1e13f25 | 217 | spin_unlock_irqrestore(lock, flags); |
1da177e4 LT |
218 | |
219 | return ret; | |
220 | } | |
221 | ||
222 | /** | |
7acd72eb | 223 | * kfifo_out_locked - gets some data from the FIFO using a spinlock for locking |
1da177e4 | 224 | * @fifo: the fifo to be used. |
c1e13f25 SS |
225 | * @to: where the data must be copied. |
226 | * @n: the size of the destination buffer. | |
227 | * @lock: pointer to the spinlock to use for locking. | |
1da177e4 | 228 | * |
72fd4a35 | 229 | * This function copies at most @len bytes from the FIFO into the |
c1e13f25 | 230 | * @to buffer and returns the number of copied bytes. |
1da177e4 | 231 | */ |
7acd72eb | 232 | static inline __must_check unsigned int kfifo_out_locked(struct kfifo *fifo, |
8ecc2951 | 233 | void *to, unsigned int n, spinlock_t *lock) |
1da177e4 LT |
234 | { |
235 | unsigned long flags; | |
236 | unsigned int ret; | |
237 | ||
c1e13f25 | 238 | spin_lock_irqsave(lock, flags); |
1da177e4 | 239 | |
7acd72eb | 240 | ret = kfifo_out(fifo, to, n); |
1da177e4 | 241 | |
c1e13f25 | 242 | spin_unlock_irqrestore(lock, flags); |
1da177e4 LT |
243 | |
244 | return ret; | |
245 | } | |
246 | ||
a121f24a SS |
247 | extern void kfifo_skip(struct kfifo *fifo, unsigned int len); |
248 | ||
64ce1037 AK |
249 | extern __must_check int kfifo_from_user(struct kfifo *fifo, |
250 | const void __user *from, unsigned int n, unsigned *lenout); | |
a121f24a | 251 | |
64ce1037 AK |
252 | extern __must_check int kfifo_to_user(struct kfifo *fifo, |
253 | void __user *to, unsigned int n, unsigned *lenout); | |
a121f24a | 254 | |
9c717de9 | 255 | /* |
a121f24a SS |
256 | * __kfifo_add_out internal helper function for updating the out offset |
257 | */ | |
258 | static inline void __kfifo_add_out(struct kfifo *fifo, | |
259 | unsigned int off) | |
260 | { | |
261 | smp_mb(); | |
262 | fifo->out += off; | |
263 | } | |
264 | ||
9c717de9 | 265 | /* |
a121f24a SS |
266 | * __kfifo_add_in internal helper function for updating the in offset |
267 | */ | |
268 | static inline void __kfifo_add_in(struct kfifo *fifo, | |
269 | unsigned int off) | |
270 | { | |
271 | smp_wmb(); | |
272 | fifo->in += off; | |
273 | } | |
274 | ||
9c717de9 | 275 | /* |
a121f24a SS |
276 | * __kfifo_off internal helper function for calculating the index of a |
277 | * given offeset | |
278 | */ | |
279 | static inline unsigned int __kfifo_off(struct kfifo *fifo, unsigned int off) | |
280 | { | |
281 | return off & (fifo->size - 1); | |
282 | } | |
283 | ||
9c717de9 | 284 | /* |
86d48803 SS |
285 | * __kfifo_peek_n internal helper function for determinate the length of |
286 | * the next record in the fifo | |
287 | */ | |
288 | static inline unsigned int __kfifo_peek_n(struct kfifo *fifo, | |
289 | unsigned int recsize) | |
290 | { | |
291 | #define __KFIFO_GET(fifo, off, shift) \ | |
292 | ((fifo)->buffer[__kfifo_off((fifo), (fifo)->out+(off))] << (shift)) | |
293 | ||
294 | unsigned int l; | |
295 | ||
296 | l = __KFIFO_GET(fifo, 0, 0); | |
297 | ||
298 | if (--recsize) | |
299 | l |= __KFIFO_GET(fifo, 1, 8); | |
300 | ||
301 | return l; | |
302 | #undef __KFIFO_GET | |
303 | } | |
304 | ||
9c717de9 | 305 | /* |
86d48803 SS |
306 | * __kfifo_poke_n internal helper function for storing the length of |
307 | * the next record into the fifo | |
308 | */ | |
309 | static inline void __kfifo_poke_n(struct kfifo *fifo, | |
310 | unsigned int recsize, unsigned int n) | |
311 | { | |
312 | #define __KFIFO_PUT(fifo, off, val, shift) \ | |
313 | ( \ | |
314 | (fifo)->buffer[__kfifo_off((fifo), (fifo)->in+(off))] = \ | |
315 | (unsigned char)((val) >> (shift)) \ | |
316 | ) | |
317 | ||
318 | __KFIFO_PUT(fifo, 0, n, 0); | |
319 | ||
320 | if (--recsize) | |
321 | __KFIFO_PUT(fifo, 1, n, 8); | |
322 | #undef __KFIFO_PUT | |
323 | } | |
324 | ||
9c717de9 | 325 | /* |
86d48803 SS |
326 | * __kfifo_in_... internal functions for put date into the fifo |
327 | * do not call it directly, use kfifo_in_rec() instead | |
328 | */ | |
329 | extern unsigned int __kfifo_in_n(struct kfifo *fifo, | |
330 | const void *from, unsigned int n, unsigned int recsize); | |
331 | ||
332 | extern unsigned int __kfifo_in_generic(struct kfifo *fifo, | |
333 | const void *from, unsigned int n, unsigned int recsize); | |
334 | ||
335 | static inline unsigned int __kfifo_in_rec(struct kfifo *fifo, | |
336 | const void *from, unsigned int n, unsigned int recsize) | |
337 | { | |
338 | unsigned int ret; | |
339 | ||
340 | ret = __kfifo_in_n(fifo, from, n, recsize); | |
341 | ||
342 | if (likely(ret == 0)) { | |
343 | if (recsize) | |
344 | __kfifo_poke_n(fifo, recsize, n); | |
345 | __kfifo_add_in(fifo, n + recsize); | |
346 | } | |
347 | return ret; | |
348 | } | |
349 | ||
350 | /** | |
351 | * kfifo_in_rec - puts some record data into the FIFO | |
352 | * @fifo: the fifo to be used. | |
353 | * @from: the data to be added. | |
354 | * @n: the length of the data to be added. | |
355 | * @recsize: size of record field | |
356 | * | |
357 | * This function copies @n bytes from the @from into the FIFO and returns | |
358 | * the number of bytes which cannot be copied. | |
359 | * A returned value greater than the @n value means that the record doesn't | |
360 | * fit into the buffer. | |
361 | * | |
362 | * Note that with only one concurrent reader and one concurrent | |
363 | * writer, you don't need extra locking to use these functions. | |
364 | */ | |
365 | static inline __must_check unsigned int kfifo_in_rec(struct kfifo *fifo, | |
366 | void *from, unsigned int n, unsigned int recsize) | |
367 | { | |
368 | if (!__builtin_constant_p(recsize)) | |
369 | return __kfifo_in_generic(fifo, from, n, recsize); | |
370 | return __kfifo_in_rec(fifo, from, n, recsize); | |
371 | } | |
372 | ||
9c717de9 | 373 | /* |
86d48803 SS |
374 | * __kfifo_out_... internal functions for get date from the fifo |
375 | * do not call it directly, use kfifo_out_rec() instead | |
376 | */ | |
377 | extern unsigned int __kfifo_out_n(struct kfifo *fifo, | |
378 | void *to, unsigned int reclen, unsigned int recsize); | |
379 | ||
380 | extern unsigned int __kfifo_out_generic(struct kfifo *fifo, | |
381 | void *to, unsigned int n, | |
382 | unsigned int recsize, unsigned int *total); | |
383 | ||
384 | static inline unsigned int __kfifo_out_rec(struct kfifo *fifo, | |
385 | void *to, unsigned int n, unsigned int recsize, | |
386 | unsigned int *total) | |
387 | { | |
388 | unsigned int l; | |
389 | ||
390 | if (!recsize) { | |
391 | l = n; | |
392 | if (total) | |
393 | *total = l; | |
394 | } else { | |
395 | l = __kfifo_peek_n(fifo, recsize); | |
396 | if (total) | |
397 | *total = l; | |
398 | if (n < l) | |
399 | return l; | |
400 | } | |
401 | ||
402 | return __kfifo_out_n(fifo, to, l, recsize); | |
403 | } | |
404 | ||
405 | /** | |
406 | * kfifo_out_rec - gets some record data from the FIFO | |
407 | * @fifo: the fifo to be used. | |
408 | * @to: where the data must be copied. | |
409 | * @n: the size of the destination buffer. | |
410 | * @recsize: size of record field | |
411 | * @total: pointer where the total number of to copied bytes should stored | |
412 | * | |
413 | * This function copies at most @n bytes from the FIFO to @to and returns the | |
414 | * number of bytes which cannot be copied. | |
415 | * A returned value greater than the @n value means that the record doesn't | |
416 | * fit into the @to buffer. | |
417 | * | |
418 | * Note that with only one concurrent reader and one concurrent | |
419 | * writer, you don't need extra locking to use these functions. | |
420 | */ | |
421 | static inline __must_check unsigned int kfifo_out_rec(struct kfifo *fifo, | |
422 | void *to, unsigned int n, unsigned int recsize, | |
423 | unsigned int *total) | |
424 | ||
425 | { | |
426 | if (!__builtin_constant_p(recsize)) | |
427 | return __kfifo_out_generic(fifo, to, n, recsize, total); | |
428 | return __kfifo_out_rec(fifo, to, n, recsize, total); | |
429 | } | |
430 | ||
9c717de9 | 431 | /* |
86d48803 SS |
432 | * __kfifo_from_user_... internal functions for transfer from user space into |
433 | * the fifo. do not call it directly, use kfifo_from_user_rec() instead | |
434 | */ | |
435 | extern unsigned int __kfifo_from_user_n(struct kfifo *fifo, | |
436 | const void __user *from, unsigned int n, unsigned int recsize); | |
437 | ||
438 | extern unsigned int __kfifo_from_user_generic(struct kfifo *fifo, | |
439 | const void __user *from, unsigned int n, unsigned int recsize); | |
440 | ||
441 | static inline unsigned int __kfifo_from_user_rec(struct kfifo *fifo, | |
442 | const void __user *from, unsigned int n, unsigned int recsize) | |
443 | { | |
444 | unsigned int ret; | |
445 | ||
446 | ret = __kfifo_from_user_n(fifo, from, n, recsize); | |
447 | ||
448 | if (likely(ret == 0)) { | |
449 | if (recsize) | |
450 | __kfifo_poke_n(fifo, recsize, n); | |
451 | __kfifo_add_in(fifo, n + recsize); | |
452 | } | |
453 | return ret; | |
454 | } | |
455 | ||
456 | /** | |
457 | * kfifo_from_user_rec - puts some data from user space into the FIFO | |
458 | * @fifo: the fifo to be used. | |
459 | * @from: pointer to the data to be added. | |
460 | * @n: the length of the data to be added. | |
461 | * @recsize: size of record field | |
462 | * | |
463 | * This function copies @n bytes from the @from into the | |
464 | * FIFO and returns the number of bytes which cannot be copied. | |
465 | * | |
466 | * If the returned value is equal or less the @n value, the copy_from_user() | |
467 | * functions has failed. Otherwise the record doesn't fit into the buffer. | |
468 | * | |
469 | * Note that with only one concurrent reader and one concurrent | |
470 | * writer, you don't need extra locking to use these functions. | |
471 | */ | |
472 | static inline __must_check unsigned int kfifo_from_user_rec(struct kfifo *fifo, | |
473 | const void __user *from, unsigned int n, unsigned int recsize) | |
474 | { | |
475 | if (!__builtin_constant_p(recsize)) | |
476 | return __kfifo_from_user_generic(fifo, from, n, recsize); | |
477 | return __kfifo_from_user_rec(fifo, from, n, recsize); | |
478 | } | |
479 | ||
9c717de9 | 480 | /* |
86d48803 SS |
481 | * __kfifo_to_user_... internal functions for transfer fifo data into user space |
482 | * do not call it directly, use kfifo_to_user_rec() instead | |
483 | */ | |
484 | extern unsigned int __kfifo_to_user_n(struct kfifo *fifo, | |
485 | void __user *to, unsigned int n, unsigned int reclen, | |
486 | unsigned int recsize); | |
487 | ||
488 | extern unsigned int __kfifo_to_user_generic(struct kfifo *fifo, | |
489 | void __user *to, unsigned int n, unsigned int recsize, | |
490 | unsigned int *total); | |
491 | ||
492 | static inline unsigned int __kfifo_to_user_rec(struct kfifo *fifo, | |
493 | void __user *to, unsigned int n, | |
494 | unsigned int recsize, unsigned int *total) | |
495 | { | |
496 | unsigned int l; | |
497 | ||
498 | if (!recsize) { | |
499 | l = n; | |
500 | if (total) | |
501 | *total = l; | |
502 | } else { | |
503 | l = __kfifo_peek_n(fifo, recsize); | |
504 | if (total) | |
505 | *total = l; | |
506 | if (n < l) | |
507 | return l; | |
508 | } | |
509 | ||
510 | return __kfifo_to_user_n(fifo, to, n, l, recsize); | |
511 | } | |
512 | ||
513 | /** | |
514 | * kfifo_to_user_rec - gets data from the FIFO and write it to user space | |
515 | * @fifo: the fifo to be used. | |
516 | * @to: where the data must be copied. | |
517 | * @n: the size of the destination buffer. | |
518 | * @recsize: size of record field | |
519 | * @total: pointer where the total number of to copied bytes should stored | |
520 | * | |
521 | * This function copies at most @n bytes from the FIFO to the @to. | |
522 | * In case of an error, the function returns the number of bytes which cannot | |
523 | * be copied. | |
524 | * If the returned value is equal or less the @n value, the copy_to_user() | |
525 | * functions has failed. Otherwise the record doesn't fit into the @to buffer. | |
526 | * | |
527 | * Note that with only one concurrent reader and one concurrent | |
528 | * writer, you don't need extra locking to use these functions. | |
529 | */ | |
530 | static inline __must_check unsigned int kfifo_to_user_rec(struct kfifo *fifo, | |
531 | void __user *to, unsigned int n, unsigned int recsize, | |
532 | unsigned int *total) | |
533 | { | |
534 | if (!__builtin_constant_p(recsize)) | |
535 | return __kfifo_to_user_generic(fifo, to, n, recsize, total); | |
536 | return __kfifo_to_user_rec(fifo, to, n, recsize, total); | |
537 | } | |
538 | ||
9c717de9 | 539 | /* |
86d48803 SS |
540 | * __kfifo_peek_... internal functions for peek into the next fifo record |
541 | * do not call it directly, use kfifo_peek_rec() instead | |
542 | */ | |
543 | extern unsigned int __kfifo_peek_generic(struct kfifo *fifo, | |
544 | unsigned int recsize); | |
545 | ||
546 | /** | |
547 | * kfifo_peek_rec - gets the size of the next FIFO record data | |
548 | * @fifo: the fifo to be used. | |
549 | * @recsize: size of record field | |
550 | * | |
551 | * This function returns the size of the next FIFO record in number of bytes | |
552 | */ | |
553 | static inline __must_check unsigned int kfifo_peek_rec(struct kfifo *fifo, | |
554 | unsigned int recsize) | |
555 | { | |
556 | if (!__builtin_constant_p(recsize)) | |
557 | return __kfifo_peek_generic(fifo, recsize); | |
558 | if (!recsize) | |
559 | return kfifo_len(fifo); | |
560 | return __kfifo_peek_n(fifo, recsize); | |
561 | } | |
562 | ||
9c717de9 | 563 | /* |
86d48803 SS |
564 | * __kfifo_skip_... internal functions for skip the next fifo record |
565 | * do not call it directly, use kfifo_skip_rec() instead | |
566 | */ | |
567 | extern void __kfifo_skip_generic(struct kfifo *fifo, unsigned int recsize); | |
568 | ||
569 | static inline void __kfifo_skip_rec(struct kfifo *fifo, | |
570 | unsigned int recsize) | |
571 | { | |
572 | unsigned int l; | |
573 | ||
574 | if (recsize) { | |
575 | l = __kfifo_peek_n(fifo, recsize); | |
576 | ||
577 | if (l + recsize <= kfifo_len(fifo)) { | |
578 | __kfifo_add_out(fifo, l + recsize); | |
579 | return; | |
580 | } | |
581 | } | |
582 | kfifo_reset_out(fifo); | |
583 | } | |
584 | ||
585 | /** | |
586 | * kfifo_skip_rec - skip the next fifo out record | |
587 | * @fifo: the fifo to be used. | |
588 | * @recsize: size of record field | |
589 | * | |
590 | * This function skips the next FIFO record | |
591 | */ | |
592 | static inline void kfifo_skip_rec(struct kfifo *fifo, | |
593 | unsigned int recsize) | |
594 | { | |
595 | if (!__builtin_constant_p(recsize)) | |
596 | __kfifo_skip_generic(fifo, recsize); | |
597 | else | |
598 | __kfifo_skip_rec(fifo, recsize); | |
599 | } | |
600 | ||
601 | /** | |
602 | * kfifo_avail_rec - returns the number of bytes available in a record FIFO | |
603 | * @fifo: the fifo to be used. | |
604 | * @recsize: size of record field | |
605 | */ | |
606 | static inline __must_check unsigned int kfifo_avail_rec(struct kfifo *fifo, | |
607 | unsigned int recsize) | |
608 | { | |
609 | unsigned int l = kfifo_size(fifo) - kfifo_len(fifo); | |
610 | ||
611 | return (l > recsize) ? l - recsize : 0; | |
612 | } | |
613 | ||
1da177e4 | 614 | #endif |