1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 /*
3 * A generic kernel FIFO implementation
4 *
5 * Copyright (C) 2013 Stefani Seibold <stefani@seibold.net>
6 */
7
8 #ifndef _LINUX_KFIFO_H
9 #define _LINUX_KFIFO_H
10
11 /*
12 * How to porting drivers to the new generic FIFO API:
13 *
14 * - Modify the declaration of the "struct kfifo *" object into a
15 * in-place "struct kfifo" object
16 * - Init the in-place object with kfifo_alloc() or kfifo_init()
17 * Note: The address of the in-place "struct kfifo" object must be
18 * passed as the first argument to this functions
19 * - Replace the use of __kfifo_put into kfifo_in and __kfifo_get
20 * into kfifo_out
21 * - Replace the use of kfifo_put into kfifo_in_spinlocked and kfifo_get
22 * into kfifo_out_spinlocked
23 * Note: the spinlock pointer formerly passed to kfifo_init/kfifo_alloc
24 * must be passed now to the kfifo_in_spinlocked and kfifo_out_spinlocked
25 * as the last parameter
26 * - The formerly __kfifo_* functions are renamed into kfifo_*
27 */
28
29 /*
30 * Note about locking: There is no locking required until only one reader
31 * and one writer is using the fifo and no kfifo_reset() will be called.
32 * kfifo_reset_out() can be safely used, until it will be only called
33 * in the reader thread.
34 * For multiple writer and one reader there is only a need to lock the writer.
35 * And vice versa for only one writer and multiple reader there is only a need
36 * to lock the reader.
37 */
38
39 #include <linux/array_size.h>
40 #include <linux/dma-mapping.h>
41 #include <linux/spinlock.h>
42 #include <linux/stddef.h>
43 #include <linux/types.h>
44
45 #include <asm/barrier.h>
46 #include <asm/errno.h>
47
48 struct scatterlist;
49
50 struct __kfifo {
51 unsigned int in;
52 unsigned int out;
53 unsigned int mask;
54 unsigned int esize;
55 void *data;
56 };
57
58 #define __STRUCT_KFIFO_COMMON(datatype, recsize, ptrtype) \
59 union { \
60 struct __kfifo kfifo; \
61 datatype *type; \
62 const datatype *const_type; \
63 char (*rectype)[recsize]; \
64 ptrtype *ptr; \
65 ptrtype const *ptr_const; \
66 }
67
68 #define __STRUCT_KFIFO(type, size, recsize, ptrtype) \
69 { \
70 __STRUCT_KFIFO_COMMON(type, recsize, ptrtype); \
71 type buf[((size < 2) || (size & (size - 1))) ? -1 : size]; \
72 }
73
74 #define STRUCT_KFIFO(type, size) \
75 struct __STRUCT_KFIFO(type, size, 0, type)
76
77 #define __STRUCT_KFIFO_PTR(type, recsize, ptrtype) \
78 { \
79 __STRUCT_KFIFO_COMMON(type, recsize, ptrtype); \
80 type buf[0]; \
81 }
82
83 #define STRUCT_KFIFO_PTR(type) \
84 struct __STRUCT_KFIFO_PTR(type, 0, type)
85
86 /*
87 * define compatibility "struct kfifo" for dynamic allocated fifos
88 */
89 struct kfifo __STRUCT_KFIFO_PTR(unsigned char, 0, void);
90
91 #define STRUCT_KFIFO_REC_1(size) \
92 struct __STRUCT_KFIFO(unsigned char, size, 1, void)
93
94 #define STRUCT_KFIFO_REC_2(size) \
95 struct __STRUCT_KFIFO(unsigned char, size, 2, void)
96
97 /*
98 * define kfifo_rec types
99 */
100 struct kfifo_rec_ptr_1 __STRUCT_KFIFO_PTR(unsigned char, 1, void);
101 struct kfifo_rec_ptr_2 __STRUCT_KFIFO_PTR(unsigned char, 2, void);
102
103 /*
104 * helper macro to distinguish between real in place fifo where the fifo
105 * array is a part of the structure and the fifo type where the array is
106 * outside of the fifo structure.
107 */
108 #define __is_kfifo_ptr(fifo) \
109 (sizeof(*fifo) == sizeof(STRUCT_KFIFO_PTR(typeof(*(fifo)->type))))
110
111 /**
112 * DECLARE_KFIFO_PTR - macro to declare a fifo pointer object
113 * @fifo: name of the declared fifo
114 * @type: type of the fifo elements
115 */
116 #define DECLARE_KFIFO_PTR(fifo, type) STRUCT_KFIFO_PTR(type) fifo
117
118 /**
119 * DECLARE_KFIFO - macro to declare a fifo object
120 * @fifo: name of the declared fifo
121 * @type: type of the fifo elements
122 * @size: the number of elements in the fifo, this must be a power of 2
123 */
124 #define DECLARE_KFIFO(fifo, type, size) STRUCT_KFIFO(type, size) fifo
125
126 /**
127 * INIT_KFIFO - Initialize a fifo declared by DECLARE_KFIFO
128 * @fifo: name of the declared fifo datatype
129 */
130 #define INIT_KFIFO(fifo) \
131 (void)({ \
132 typeof(&(fifo)) __tmp = &(fifo); \
133 struct __kfifo *__kfifo = &__tmp->kfifo; \
134 __kfifo->in = 0; \
135 __kfifo->out = 0; \
136 __kfifo->mask = __is_kfifo_ptr(__tmp) ? 0 : ARRAY_SIZE(__tmp->buf) - 1;\
137 __kfifo->esize = sizeof(*__tmp->buf); \
138 __kfifo->data = __is_kfifo_ptr(__tmp) ? NULL : __tmp->buf; \
139 })
140
141 /**
142 * DEFINE_KFIFO - macro to define and initialize a fifo
143 * @fifo: name of the declared fifo datatype
144 * @type: type of the fifo elements
145 * @size: the number of elements in the fifo, this must be a power of 2
146 *
147 * Note: the macro can be used for global and local fifo data type variables.
148 */
149 #define DEFINE_KFIFO(fifo, type, size) \
150 DECLARE_KFIFO(fifo, type, size) = \
151 (typeof(fifo)) { \
152 { \
153 { \
154 .in = 0, \
155 .out = 0, \
156 .mask = __is_kfifo_ptr(&(fifo)) ? \
157 0 : \
158 ARRAY_SIZE((fifo).buf) - 1, \
159 .esize = sizeof(*(fifo).buf), \
160 .data = __is_kfifo_ptr(&(fifo)) ? \
161 NULL : \
162 (fifo).buf, \
163 } \
164 } \
165 }
166
167
168 static inline unsigned int __must_check
169 __kfifo_uint_must_check_helper(unsigned int val)
170 {
171 return val;
172 }
173
174 static inline int __must_check
175 __kfifo_int_must_check_helper(int val)
176 {
177 return val;
178 }
179
180 /**
181 * kfifo_initialized - Check if the fifo is initialized
182 * @fifo: address of the fifo to check
183 *
184 * Return %true if fifo is initialized, otherwise %false.
185 * Assumes the fifo was 0 before.
186 */
187 #define kfifo_initialized(fifo) ((fifo)->kfifo.mask)
188
189 /**
190 * kfifo_esize - returns the size of the element managed by the fifo
191 * @fifo: address of the fifo to be used
192 */
193 #define kfifo_esize(fifo) ((fifo)->kfifo.esize)
194
195 /**
196 * kfifo_recsize - returns the size of the record length field
197 * @fifo: address of the fifo to be used
198 */
199 #define kfifo_recsize(fifo) (sizeof(*(fifo)->rectype))
200
201 /**
202 * kfifo_size - returns the size of the fifo in elements
203 * @fifo: address of the fifo to be used
204 */
205 #define kfifo_size(fifo) ((fifo)->kfifo.mask + 1)
206
207 /**
208 * kfifo_reset - removes the entire fifo content
209 * @fifo: address of the fifo to be used
210 *
211 * Note: usage of kfifo_reset() is dangerous. It should be only called when the
212 * fifo is exclusived locked or when it is secured that no other thread is
213 * accessing the fifo.
214 */
215 #define kfifo_reset(fifo) \
216 (void)({ \
217 typeof((fifo) + 1) __tmp = (fifo); \
218 __tmp->kfifo.in = __tmp->kfifo.out = 0; \
219 })
220
221 /**
222 * kfifo_reset_out - skip fifo content
223 * @fifo: address of the fifo to be used
224 *
225 * Note: The usage of kfifo_reset_out() is safe until it will be only called
226 * from the reader thread and there is only one concurrent reader. Otherwise
227 * it is dangerous and must be handled in the same way as kfifo_reset().
228 */
229 #define kfifo_reset_out(fifo) \
230 (void)({ \
231 typeof((fifo) + 1) __tmp = (fifo); \
232 __tmp->kfifo.out = __tmp->kfifo.in; \
233 })
234
235 /**
236 * kfifo_len - returns the number of used elements in the fifo
237 * @fifo: address of the fifo to be used
238 */
239 #define kfifo_len(fifo) \
240 ({ \
241 typeof((fifo) + 1) __tmpl = (fifo); \
242 __tmpl->kfifo.in - __tmpl->kfifo.out; \
243 })
244
245 /**
246 * kfifo_is_empty - returns true if the fifo is empty
247 * @fifo: address of the fifo to be used
248 */
249 #define kfifo_is_empty(fifo) \
250 ({ \
251 typeof((fifo) + 1) __tmpq = (fifo); \
252 __tmpq->kfifo.in == __tmpq->kfifo.out; \
253 })
254
255 /**
256 * kfifo_is_empty_spinlocked - returns true if the fifo is empty using
257 * a spinlock for locking
258 * @fifo: address of the fifo to be used
259 * @lock: spinlock to be used for locking
260 */
261 #define kfifo_is_empty_spinlocked(fifo, lock) \
262 ({ \
263 unsigned long __flags; \
264 bool __ret; \
265 spin_lock_irqsave(lock, __flags); \
266 __ret = kfifo_is_empty(fifo); \
267 spin_unlock_irqrestore(lock, __flags); \
268 __ret; \
269 })
270
271 /**
272 * kfifo_is_empty_spinlocked_noirqsave - returns true if the fifo is empty
273 * using a spinlock for locking, doesn't disable interrupts
274 * @fifo: address of the fifo to be used
275 * @lock: spinlock to be used for locking
276 */
277 #define kfifo_is_empty_spinlocked_noirqsave(fifo, lock) \
278 ({ \
279 bool __ret; \
280 spin_lock(lock); \
281 __ret = kfifo_is_empty(fifo); \
282 spin_unlock(lock); \
283 __ret; \
284 })
285
286 /**
287 * kfifo_is_full - returns true if the fifo is full
288 * @fifo: address of the fifo to be used
289 */
290 #define kfifo_is_full(fifo) \
291 ({ \
292 typeof((fifo) + 1) __tmpq = (fifo); \
293 kfifo_len(__tmpq) > __tmpq->kfifo.mask; \
294 })
295
296 /**
297 * kfifo_avail - returns the number of unused elements in the fifo
298 * @fifo: address of the fifo to be used
299 */
300 #define kfifo_avail(fifo) \
301 __kfifo_uint_must_check_helper( \
302 ({ \
303 typeof((fifo) + 1) __tmpq = (fifo); \
304 const size_t __recsize = sizeof(*__tmpq->rectype); \
305 unsigned int __avail = kfifo_size(__tmpq) - kfifo_len(__tmpq); \
306 (__recsize) ? ((__avail <= __recsize) ? 0 : \
307 __kfifo_max_r(__avail - __recsize, __recsize)) : \
308 __avail; \
309 }) \
310 )
311
312 /**
313 * kfifo_skip_count - skip output data
314 * @fifo: address of the fifo to be used
315 * @count: count of data to skip
316 */
317 #define kfifo_skip_count(fifo, count) do { \
318 typeof((fifo) + 1) __tmp = (fifo); \
319 const size_t __recsize = sizeof(*__tmp->rectype); \
320 struct __kfifo *__kfifo = &__tmp->kfifo; \
321 if (__recsize) \
322 __kfifo_skip_r(__kfifo, __recsize); \
323 else \
324 __kfifo->out += (count); \
325 } while(0)
326
327 /**
328 * kfifo_skip - skip output data
329 * @fifo: address of the fifo to be used
330 */
331 #define kfifo_skip(fifo) kfifo_skip_count(fifo, 1)
332
333 /**
334 * kfifo_peek_len - gets the size of the next fifo record
335 * @fifo: address of the fifo to be used
336 *
337 * This function returns the size of the next fifo record in number of bytes.
338 */
339 #define kfifo_peek_len(fifo) \
340 __kfifo_uint_must_check_helper( \
341 ({ \
342 typeof((fifo) + 1) __tmp = (fifo); \
343 const size_t __recsize = sizeof(*__tmp->rectype); \
344 struct __kfifo *__kfifo = &__tmp->kfifo; \
345 (!__recsize) ? kfifo_len(__tmp) * sizeof(*__tmp->type) : \
346 __kfifo_len_r(__kfifo, __recsize); \
347 }) \
348 )
349
350 /**
351 * kfifo_alloc - dynamically allocates a new fifo buffer
352 * @fifo: pointer to the fifo
353 * @size: the number of elements in the fifo, this must be a power of 2
354 * @gfp_mask: get_free_pages mask, passed to kmalloc()
355 *
356 * This macro dynamically allocates a new fifo buffer.
357 *
358 * The number of elements will be rounded-up to a power of 2.
359 * The fifo will be release with kfifo_free().
360 * Return 0 if no error, otherwise an error code.
361 */
362 #define kfifo_alloc(fifo, size, gfp_mask) \
363 __kfifo_int_must_check_helper( \
364 ({ \
365 typeof((fifo) + 1) __tmp = (fifo); \
366 struct __kfifo *__kfifo = &__tmp->kfifo; \
367 __is_kfifo_ptr(__tmp) ? \
368 __kfifo_alloc(__kfifo, size, sizeof(*__tmp->type), gfp_mask) : \
369 -EINVAL; \
370 }) \
371 )
372
373 /**
374 * kfifo_free - frees the fifo
375 * @fifo: the fifo to be freed
376 */
377 #define kfifo_free(fifo) \
378 ({ \
379 typeof((fifo) + 1) __tmp = (fifo); \
380 struct __kfifo *__kfifo = &__tmp->kfifo; \
381 if (__is_kfifo_ptr(__tmp)) \
382 __kfifo_free(__kfifo); \
383 })
384
385 /**
386 * kfifo_init - initialize a fifo using a preallocated buffer
387 * @fifo: the fifo to assign the buffer
388 * @buffer: the preallocated buffer to be used
389 * @size: the size of the internal buffer, this have to be a power of 2
390 *
391 * This macro initializes a fifo using a preallocated buffer.
392 *
393 * The number of elements will be rounded-up to a power of 2.
394 * Return 0 if no error, otherwise an error code.
395 */
396 #define kfifo_init(fifo, buffer, size) \
397 ({ \
398 typeof((fifo) + 1) __tmp = (fifo); \
399 struct __kfifo *__kfifo = &__tmp->kfifo; \
400 __is_kfifo_ptr(__tmp) ? \
401 __kfifo_init(__kfifo, buffer, size, sizeof(*__tmp->type)) : \
402 -EINVAL; \
403 })
404
405 /**
406 * kfifo_put - put data into the fifo
407 * @fifo: address of the fifo to be used
408 * @val: the data to be added
409 *
410 * This macro copies the given value into the fifo.
411 * It returns 0 if the fifo was full. Otherwise it returns the number
412 * processed elements.
413 *
414 * Note that with only one concurrent reader and one concurrent
415 * writer, you don't need extra locking to use these macro.
416 */
417 #define kfifo_put(fifo, val) \
418 ({ \
419 typeof((fifo) + 1) __tmp = (fifo); \
420 typeof(*__tmp->const_type) __val = (val); \
421 unsigned int __ret; \
422 size_t __recsize = sizeof(*__tmp->rectype); \
423 struct __kfifo *__kfifo = &__tmp->kfifo; \
424 if (__recsize) \
425 __ret = __kfifo_in_r(__kfifo, &__val, sizeof(__val), \
426 __recsize); \
427 else { \
428 __ret = !kfifo_is_full(__tmp); \
429 if (__ret) { \
430 (__is_kfifo_ptr(__tmp) ? \
431 ((typeof(__tmp->type))__kfifo->data) : \
432 (__tmp->buf) \
433 )[__kfifo->in & __tmp->kfifo.mask] = \
434 *(typeof(__tmp->type))&__val; \
435 smp_wmb(); \
436 __kfifo->in++; \
437 } \
438 } \
439 __ret; \
440 })
441
442 /**
443 * kfifo_get - get data from the fifo
444 * @fifo: address of the fifo to be used
445 * @val: address where to store the data
446 *
447 * This macro reads the data from the fifo.
448 * It returns 0 if the fifo was empty. Otherwise it returns the number
449 * processed elements.
450 *
451 * Note that with only one concurrent reader and one concurrent
452 * writer, you don't need extra locking to use these macro.
453 */
454 #define kfifo_get(fifo, val) \
455 __kfifo_uint_must_check_helper( \
456 ({ \
457 typeof((fifo) + 1) __tmp = (fifo); \
458 typeof(__tmp->ptr) __val = (val); \
459 unsigned int __ret; \
460 const size_t __recsize = sizeof(*__tmp->rectype); \
461 struct __kfifo *__kfifo = &__tmp->kfifo; \
462 if (__recsize) \
463 __ret = __kfifo_out_r(__kfifo, __val, sizeof(*__val), \
464 __recsize); \
465 else { \
466 __ret = !kfifo_is_empty(__tmp); \
467 if (__ret) { \
468 *(typeof(__tmp->type))__val = \
469 (__is_kfifo_ptr(__tmp) ? \
470 ((typeof(__tmp->type))__kfifo->data) : \
471 (__tmp->buf) \
472 )[__kfifo->out & __tmp->kfifo.mask]; \
473 smp_wmb(); \
474 __kfifo->out++; \
475 } \
476 } \
477 __ret; \
478 }) \
479 )
480
481 /**
482 * kfifo_peek - get data from the fifo without removing
483 * @fifo: address of the fifo to be used
484 * @val: address where to store the data
485 *
486 * This reads the data from the fifo without removing it from the fifo.
487 * It returns 0 if the fifo was empty. Otherwise it returns the number
488 * processed elements.
489 *
490 * Note that with only one concurrent reader and one concurrent
491 * writer, you don't need extra locking to use these macro.
492 */
493 #define kfifo_peek(fifo, val) \
494 __kfifo_uint_must_check_helper( \
495 ({ \
496 typeof((fifo) + 1) __tmp = (fifo); \
497 typeof(__tmp->ptr) __val = (val); \
498 unsigned int __ret; \
499 const size_t __recsize = sizeof(*__tmp->rectype); \
500 struct __kfifo *__kfifo = &__tmp->kfifo; \
501 if (__recsize) \
502 __ret = __kfifo_out_peek_r(__kfifo, __val, sizeof(*__val), \
503 __recsize); \
504 else { \
505 __ret = !kfifo_is_empty(__tmp); \
506 if (__ret) { \
507 *(typeof(__tmp->type))__val = \
508 (__is_kfifo_ptr(__tmp) ? \
509 ((typeof(__tmp->type))__kfifo->data) : \
510 (__tmp->buf) \
511 )[__kfifo->out & __tmp->kfifo.mask]; \
512 smp_wmb(); \
513 } \
514 } \
515 __ret; \
516 }) \
517 )
518
519 /**
520 * kfifo_in - put data into the fifo
521 * @fifo: address of the fifo to be used
522 * @buf: the data to be added
523 * @n: number of elements to be added
524 *
525 * This macro copies the given buffer into the fifo and returns the
526 * number of copied elements.
527 *
528 * Note that with only one concurrent reader and one concurrent
529 * writer, you don't need extra locking to use these macro.
530 */
531 #define kfifo_in(fifo, buf, n) \
532 ({ \
533 typeof((fifo) + 1) __tmp = (fifo); \
534 typeof(__tmp->ptr_const) __buf = (buf); \
535 unsigned long __n = (n); \
536 const size_t __recsize = sizeof(*__tmp->rectype); \
537 struct __kfifo *__kfifo = &__tmp->kfifo; \
538 (__recsize) ?\
539 __kfifo_in_r(__kfifo, __buf, __n, __recsize) : \
540 __kfifo_in(__kfifo, __buf, __n); \
541 })
542
543 /**
544 * kfifo_in_spinlocked - put data into the fifo using a spinlock for locking
545 * @fifo: address of the fifo to be used
546 * @buf: the data to be added
547 * @n: number of elements to be added
548 * @lock: pointer to the spinlock to use for locking
549 *
550 * This macro copies the given values buffer into the fifo and returns the
551 * number of copied elements.
552 */
553 #define kfifo_in_spinlocked(fifo, buf, n, lock) \
554 ({ \
555 unsigned long __flags; \
556 unsigned int __ret; \
557 spin_lock_irqsave(lock, __flags); \
558 __ret = kfifo_in(fifo, buf, n); \
559 spin_unlock_irqrestore(lock, __flags); \
560 __ret; \
561 })
562
563 /**
564 * kfifo_in_spinlocked_noirqsave - put data into fifo using a spinlock for
565 * locking, don't disable interrupts
566 * @fifo: address of the fifo to be used
567 * @buf: the data to be added
568 * @n: number of elements to be added
569 * @lock: pointer to the spinlock to use for locking
570 *
571 * This is a variant of kfifo_in_spinlocked() but uses spin_lock/unlock()
572 * for locking and doesn't disable interrupts.
573 */
574 #define kfifo_in_spinlocked_noirqsave(fifo, buf, n, lock) \
575 ({ \
576 unsigned int __ret; \
577 spin_lock(lock); \
578 __ret = kfifo_in(fifo, buf, n); \
579 spin_unlock(lock); \
580 __ret; \
581 })
582
583 /* alias for kfifo_in_spinlocked, will be removed in a future release */
584 #define kfifo_in_locked(fifo, buf, n, lock) \
585 kfifo_in_spinlocked(fifo, buf, n, lock)
586
587 /**
588 * kfifo_out - get data from the fifo
589 * @fifo: address of the fifo to be used
590 * @buf: pointer to the storage buffer
591 * @n: max. number of elements to get
592 *
593 * This macro gets some data from the fifo and returns the numbers of elements
594 * copied.
595 *
596 * Note that with only one concurrent reader and one concurrent
597 * writer, you don't need extra locking to use these macro.
598 */
599 #define kfifo_out(fifo, buf, n) \
600 __kfifo_uint_must_check_helper( \
601 ({ \
602 typeof((fifo) + 1) __tmp = (fifo); \
603 typeof(__tmp->ptr) __buf = (buf); \
604 unsigned long __n = (n); \
605 const size_t __recsize = sizeof(*__tmp->rectype); \
606 struct __kfifo *__kfifo = &__tmp->kfifo; \
607 (__recsize) ?\
608 __kfifo_out_r(__kfifo, __buf, __n, __recsize) : \
609 __kfifo_out(__kfifo, __buf, __n); \
610 }) \
611 )
612
613 /**
614 * kfifo_out_spinlocked - get data from the fifo using a spinlock for locking
615 * @fifo: address of the fifo to be used
616 * @buf: pointer to the storage buffer
617 * @n: max. number of elements to get
618 * @lock: pointer to the spinlock to use for locking
619 *
620 * This macro gets the data from the fifo and returns the numbers of elements
621 * copied.
622 */
623 #define kfifo_out_spinlocked(fifo, buf, n, lock) \
624 __kfifo_uint_must_check_helper( \
625 ({ \
626 unsigned long __flags; \
627 unsigned int __ret; \
628 spin_lock_irqsave(lock, __flags); \
629 __ret = kfifo_out(fifo, buf, n); \
630 spin_unlock_irqrestore(lock, __flags); \
631 __ret; \
632 }) \
633 )
634
635 /**
636 * kfifo_out_spinlocked_noirqsave - get data from the fifo using a spinlock
637 * for locking, don't disable interrupts
638 * @fifo: address of the fifo to be used
639 * @buf: pointer to the storage buffer
640 * @n: max. number of elements to get
641 * @lock: pointer to the spinlock to use for locking
642 *
643 * This is a variant of kfifo_out_spinlocked() which uses spin_lock/unlock()
644 * for locking and doesn't disable interrupts.
645 */
646 #define kfifo_out_spinlocked_noirqsave(fifo, buf, n, lock) \
647 __kfifo_uint_must_check_helper( \
648 ({ \
649 unsigned int __ret; \
650 spin_lock(lock); \
651 __ret = kfifo_out(fifo, buf, n); \
652 spin_unlock(lock); \
653 __ret; \
654 }) \
655 )
656
657 /* alias for kfifo_out_spinlocked, will be removed in a future release */
658 #define kfifo_out_locked(fifo, buf, n, lock) \
659 kfifo_out_spinlocked(fifo, buf, n, lock)
660
661 /**
662 * kfifo_from_user - puts some data from user space into the fifo
663 * @fifo: address of the fifo to be used
664 * @from: pointer to the data to be added
665 * @len: the length of the data to be added
666 * @copied: pointer to output variable to store the number of copied bytes
667 *
668 * This macro copies at most @len bytes from the @from into the
669 * fifo, depending of the available space and returns -EFAULT/0.
670 *
671 * Note that with only one concurrent reader and one concurrent
672 * writer, you don't need extra locking to use these macro.
673 */
674 #define kfifo_from_user(fifo, from, len, copied) \
675 __kfifo_uint_must_check_helper( \
676 ({ \
677 typeof((fifo) + 1) __tmp = (fifo); \
678 const void __user *__from = (from); \
679 unsigned int __len = (len); \
680 unsigned int *__copied = (copied); \
681 const size_t __recsize = sizeof(*__tmp->rectype); \
682 struct __kfifo *__kfifo = &__tmp->kfifo; \
683 (__recsize) ? \
684 __kfifo_from_user_r(__kfifo, __from, __len, __copied, __recsize) : \
685 __kfifo_from_user(__kfifo, __from, __len, __copied); \
686 }) \
687 )
688
689 /**
690 * kfifo_to_user - copies data from the fifo into user space
691 * @fifo: address of the fifo to be used
692 * @to: where the data must be copied
693 * @len: the size of the destination buffer
694 * @copied: pointer to output variable to store the number of copied bytes
695 *
696 * This macro copies at most @len bytes from the fifo into the
697 * @to buffer and returns -EFAULT/0.
698 *
699 * Note that with only one concurrent reader and one concurrent
700 * writer, you don't need extra locking to use these macro.
701 */
702 #define kfifo_to_user(fifo, to, len, copied) \
703 __kfifo_int_must_check_helper( \
704 ({ \
705 typeof((fifo) + 1) __tmp = (fifo); \
706 void __user *__to = (to); \
707 unsigned int __len = (len); \
708 unsigned int *__copied = (copied); \
709 const size_t __recsize = sizeof(*__tmp->rectype); \
710 struct __kfifo *__kfifo = &__tmp->kfifo; \
711 (__recsize) ? \
712 __kfifo_to_user_r(__kfifo, __to, __len, __copied, __recsize) : \
713 __kfifo_to_user(__kfifo, __to, __len, __copied); \
714 }) \
715 )
716
717 /**
718 * kfifo_dma_in_prepare_mapped - setup a scatterlist for DMA input
719 * @fifo: address of the fifo to be used
720 * @sgl: pointer to the scatterlist array
721 * @nents: number of entries in the scatterlist array
722 * @len: number of elements to transfer
723 * @dma: mapped dma address to fill into @sgl
724 *
725 * This macro fills a scatterlist for DMA input.
726 * It returns the number entries in the scatterlist array.
727 *
728 * Note that with only one concurrent reader and one concurrent
729 * writer, you don't need extra locking to use these macros.
730 */
731 #define kfifo_dma_in_prepare_mapped(fifo, sgl, nents, len, dma) \
732 ({ \
733 typeof((fifo) + 1) __tmp = (fifo); \
734 struct scatterlist *__sgl = (sgl); \
735 int __nents = (nents); \
736 unsigned int __len = (len); \
737 const size_t __recsize = sizeof(*__tmp->rectype); \
738 struct __kfifo *__kfifo = &__tmp->kfifo; \
739 (__recsize) ? \
740 __kfifo_dma_in_prepare_r(__kfifo, __sgl, __nents, __len, __recsize, \
741 dma) : \
742 __kfifo_dma_in_prepare(__kfifo, __sgl, __nents, __len, dma); \
743 })
744
745 #define kfifo_dma_in_prepare(fifo, sgl, nents, len) \
746 kfifo_dma_in_prepare_mapped(fifo, sgl, nents, len, DMA_MAPPING_ERROR)
747
748 /**
749 * kfifo_dma_in_finish - finish a DMA IN operation
750 * @fifo: address of the fifo to be used
751 * @len: number of bytes to received
752 *
753 * This macro finishes a DMA IN operation. The in counter will be updated by
754 * the len parameter. No error checking will be done.
755 *
756 * Note that with only one concurrent reader and one concurrent
757 * writer, you don't need extra locking to use these macros.
758 */
759 #define kfifo_dma_in_finish(fifo, len) \
760 (void)({ \
761 typeof((fifo) + 1) __tmp = (fifo); \
762 unsigned int __len = (len); \
763 const size_t __recsize = sizeof(*__tmp->rectype); \
764 struct __kfifo *__kfifo = &__tmp->kfifo; \
765 if (__recsize) \
766 __kfifo_dma_in_finish_r(__kfifo, __len, __recsize); \
767 else \
768 __kfifo->in += __len / sizeof(*__tmp->type); \
769 })
770
771 /**
772 * kfifo_dma_out_prepare_mapped - setup a scatterlist for DMA output
773 * @fifo: address of the fifo to be used
774 * @sgl: pointer to the scatterlist array
775 * @nents: number of entries in the scatterlist array
776 * @len: number of elements to transfer
777 * @dma: mapped dma address to fill into @sgl
778 *
779 * This macro fills a scatterlist for DMA output which at most @len bytes
780 * to transfer.
781 * It returns the number entries in the scatterlist array.
782 * A zero means there is no space available and the scatterlist is not filled.
783 *
784 * Note that with only one concurrent reader and one concurrent
785 * writer, you don't need extra locking to use these macros.
786 */
787 #define kfifo_dma_out_prepare_mapped(fifo, sgl, nents, len, dma) \
788 ({ \
789 typeof((fifo) + 1) __tmp = (fifo); \
790 struct scatterlist *__sgl = (sgl); \
791 int __nents = (nents); \
792 unsigned int __len = (len); \
793 const size_t __recsize = sizeof(*__tmp->rectype); \
794 struct __kfifo *__kfifo = &__tmp->kfifo; \
795 (__recsize) ? \
796 __kfifo_dma_out_prepare_r(__kfifo, __sgl, __nents, __len, __recsize, \
797 dma) : \
798 __kfifo_dma_out_prepare(__kfifo, __sgl, __nents, __len, dma); \
799 })
800
801 #define kfifo_dma_out_prepare(fifo, sgl, nents, len) \
802 kfifo_dma_out_prepare_mapped(fifo, sgl, nents, len, DMA_MAPPING_ERROR)
803
804 /**
805 * kfifo_dma_out_finish - finish a DMA OUT operation
806 * @fifo: address of the fifo to be used
807 * @len: number of bytes transferred
808 *
809 * This macro finishes a DMA OUT operation. The out counter will be updated by
810 * the len parameter. No error checking will be done.
811 *
812 * Note that with only one concurrent reader and one concurrent
813 * writer, you don't need extra locking to use these macros.
814 */
815 #define kfifo_dma_out_finish(fifo, len) do { \
816 typeof((fifo) + 1) ___tmp = (fifo); \
817 kfifo_skip_count(___tmp, (len) / sizeof(*___tmp->type)); \
818 } while (0)
819
820 /**
821 * kfifo_out_peek - gets some data from the fifo
822 * @fifo: address of the fifo to be used
823 * @buf: pointer to the storage buffer
824 * @n: max. number of elements to get
825 *
826 * This macro gets the data from the fifo and returns the numbers of elements
827 * copied. The data is not removed from the fifo.
828 *
829 * Note that with only one concurrent reader and one concurrent
830 * writer, you don't need extra locking to use these macro.
831 */
832 #define kfifo_out_peek(fifo, buf, n) \
833 __kfifo_uint_must_check_helper( \
834 ({ \
835 typeof((fifo) + 1) __tmp = (fifo); \
836 typeof(__tmp->ptr) __buf = (buf); \
837 unsigned long __n = (n); \
838 const size_t __recsize = sizeof(*__tmp->rectype); \
839 struct __kfifo *__kfifo = &__tmp->kfifo; \
840 (__recsize) ? \
841 __kfifo_out_peek_r(__kfifo, __buf, __n, __recsize) : \
842 __kfifo_out_peek(__kfifo, __buf, __n); \
843 }) \
844 )
845
846 /**
847 * kfifo_out_linear - gets a tail of/offset to available data
848 * @fifo: address of the fifo to be used
849 * @tail: pointer to an unsigned int to store the value of tail
850 * @n: max. number of elements to point at
851 *
852 * This macro obtains the offset (tail) to the available data in the fifo
853 * buffer and returns the
854 * numbers of elements available. It returns the available count till the end
855 * of data or till the end of the buffer. So that it can be used for linear
856 * data processing (like memcpy() of (@fifo->data + @tail) with count
857 * returned).
858 *
859 * Note that with only one concurrent reader and one concurrent
860 * writer, you don't need extra locking to use these macro.
861 */
862 #define kfifo_out_linear(fifo, tail, n) \
863 __kfifo_uint_must_check_helper( \
864 ({ \
865 typeof((fifo) + 1) __tmp = (fifo); \
866 unsigned int *__tail = (tail); \
867 unsigned long __n = (n); \
868 const size_t __recsize = sizeof(*__tmp->rectype); \
869 struct __kfifo *__kfifo = &__tmp->kfifo; \
870 (__recsize) ? \
871 __kfifo_out_linear_r(__kfifo, __tail, __n, __recsize) : \
872 __kfifo_out_linear(__kfifo, __tail, __n); \
873 }) \
874 )
875
876 /**
877 * kfifo_out_linear_ptr - gets a pointer to the available data
878 * @fifo: address of the fifo to be used
879 * @ptr: pointer to data to store the pointer to tail
880 * @n: max. number of elements to point at
881 *
882 * Similarly to kfifo_out_linear(), this macro obtains the pointer to the
883 * available data in the fifo buffer and returns the numbers of elements
884 * available. It returns the available count till the end of available data or
885 * till the end of the buffer. So that it can be used for linear data
886 * processing (like memcpy() of @ptr with count returned).
887 *
888 * Note that with only one concurrent reader and one concurrent
889 * writer, you don't need extra locking to use these macro.
890 */
891 #define kfifo_out_linear_ptr(fifo, ptr, n) \
892 __kfifo_uint_must_check_helper( \
893 ({ \
894 typeof((fifo) + 1) ___tmp = (fifo); \
895 unsigned int ___tail; \
896 unsigned int ___n = kfifo_out_linear(___tmp, &___tail, (n)); \
897 *(ptr) = ___tmp->kfifo.data + ___tail * kfifo_esize(___tmp); \
898 ___n; \
899 }) \
900 )
901
902
903 extern int __kfifo_alloc(struct __kfifo *fifo, unsigned int size,
904 size_t esize, gfp_t gfp_mask);
905
906 extern void __kfifo_free(struct __kfifo *fifo);
907
908 extern int __kfifo_init(struct __kfifo *fifo, void *buffer,
909 unsigned int size, size_t esize);
910
911 extern unsigned int __kfifo_in(struct __kfifo *fifo,
912 const void *buf, unsigned int len);
913
914 extern unsigned int __kfifo_out(struct __kfifo *fifo,
915 void *buf, unsigned int len);
916
917 extern int __kfifo_from_user(struct __kfifo *fifo,
918 const void __user *from, unsigned long len, unsigned int *copied);
919
920 extern int __kfifo_to_user(struct __kfifo *fifo,
921 void __user *to, unsigned long len, unsigned int *copied);
922
923 extern unsigned int __kfifo_dma_in_prepare(struct __kfifo *fifo,
924 struct scatterlist *sgl, int nents, unsigned int len, dma_addr_t dma);
925
926 extern unsigned int __kfifo_dma_out_prepare(struct __kfifo *fifo,
927 struct scatterlist *sgl, int nents, unsigned int len, dma_addr_t dma);
928
929 extern unsigned int __kfifo_out_peek(struct __kfifo *fifo,
930 void *buf, unsigned int len);
931
932 extern unsigned int __kfifo_out_linear(struct __kfifo *fifo,
933 unsigned int *tail, unsigned int n);
934
935 extern unsigned int __kfifo_in_r(struct __kfifo *fifo,
936 const void *buf, unsigned int len, size_t recsize);
937
938 extern unsigned int __kfifo_out_r(struct __kfifo *fifo,
939 void *buf, unsigned int len, size_t recsize);
940
941 extern int __kfifo_from_user_r(struct __kfifo *fifo,
942 const void __user *from, unsigned long len, unsigned int *copied,
943 size_t recsize);
944
945 extern int __kfifo_to_user_r(struct __kfifo *fifo, void __user *to,
946 unsigned long len, unsigned int *copied, size_t recsize);
947
948 extern unsigned int __kfifo_dma_in_prepare_r(struct __kfifo *fifo,
949 struct scatterlist *sgl, int nents, unsigned int len, size_t recsize,
950 dma_addr_t dma);
951
952 extern void __kfifo_dma_in_finish_r(struct __kfifo *fifo,
953 unsigned int len, size_t recsize);
954
955 extern unsigned int __kfifo_dma_out_prepare_r(struct __kfifo *fifo,
956 struct scatterlist *sgl, int nents, unsigned int len, size_t recsize,
957 dma_addr_t dma);
958
959 extern unsigned int __kfifo_len_r(struct __kfifo *fifo, size_t recsize);
960
961 extern void __kfifo_skip_r(struct __kfifo *fifo, size_t recsize);
962
963 extern unsigned int __kfifo_out_peek_r(struct __kfifo *fifo,
964 void *buf, unsigned int len, size_t recsize);
965
966 extern unsigned int __kfifo_out_linear_r(struct __kfifo *fifo,
967 unsigned int *tail, unsigned int n, size_t recsize);
968
969 extern unsigned int __kfifo_max_r(unsigned int len, size_t recsize);
970
971 #endif
972
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