1/*
2 * A generic kernel FIFO implementation
3 *
4 * Copyright (C) 2013 Stefani Seibold <stefani@seibold.net>
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
19 *
20 */
21
22#ifndef _LINUX_KFIFO_H
23#define _LINUX_KFIFO_H
24
25/*
26 * How to porting drivers to the new generic FIFO API:
27 *
28 * - Modify the declaration of the "struct kfifo *" object into a
29 * in-place "struct kfifo" object
30 * - Init the in-place object with kfifo_alloc() or kfifo_init()
31 * Note: The address of the in-place "struct kfifo" object must be
32 * passed as the first argument to this functions
33 * - Replace the use of __kfifo_put into kfifo_in and __kfifo_get
34 * into kfifo_out
35 * - Replace the use of kfifo_put into kfifo_in_spinlocked and kfifo_get
36 * into kfifo_out_spinlocked
37 * Note: the spinlock pointer formerly passed to kfifo_init/kfifo_alloc
38 * must be passed now to the kfifo_in_spinlocked and kfifo_out_spinlocked
39 * as the last parameter
40 * - The formerly __kfifo_* functions are renamed into kfifo_*
41 */
42
43/*
44 * Note about locking: There is no locking required until only one reader
45 * and one writer is using the fifo and no kfifo_reset() will be called.
46 * kfifo_reset_out() can be safely used, until it will be only called
47 * in the reader thread.
48 * For multiple writer and one reader there is only a need to lock the writer.
49 * And vice versa for only one writer and multiple reader there is only a need
50 * to lock the reader.
51 */
52
53#include <linux/kernel.h>
54#include <linux/spinlock.h>
55#include <linux/stddef.h>
56#include <linux/scatterlist.h>
57
58struct __kfifo {
59 unsigned int in;
60 unsigned int out;
61 unsigned int mask;
62 unsigned int esize;
63 void *data;
64};
65
66#define __STRUCT_KFIFO_COMMON(datatype, recsize, ptrtype) \
67 union { \
68 struct __kfifo kfifo; \
69 datatype *type; \
70 const datatype *const_type; \
71 char (*rectype)[recsize]; \
72 ptrtype *ptr; \
73 ptrtype const *ptr_const; \
74 }
75
76#define __STRUCT_KFIFO(type, size, recsize, ptrtype) \
77{ \
78 __STRUCT_KFIFO_COMMON(type, recsize, ptrtype); \
79 type buf[((size < 2) || (size & (size - 1))) ? -1 : size]; \
80}
81
82#define STRUCT_KFIFO(type, size) \
83 struct __STRUCT_KFIFO(type, size, 0, type)
84
85#define __STRUCT_KFIFO_PTR(type, recsize, ptrtype) \
86{ \
87 __STRUCT_KFIFO_COMMON(type, recsize, ptrtype); \
88 type buf[0]; \
89}
90
91#define STRUCT_KFIFO_PTR(type) \
92 struct __STRUCT_KFIFO_PTR(type, 0, type)
93
94/*
95 * define compatibility "struct kfifo" for dynamic allocated fifos
96 */
97struct kfifo __STRUCT_KFIFO_PTR(unsigned char, 0, void);
98
99#define STRUCT_KFIFO_REC_1(size) \
100 struct __STRUCT_KFIFO(unsigned char, size, 1, void)
101
102#define STRUCT_KFIFO_REC_2(size) \
103 struct __STRUCT_KFIFO(unsigned char, size, 2, void)
104
105/*
106 * define kfifo_rec types
107 */
108struct kfifo_rec_ptr_1 __STRUCT_KFIFO_PTR(unsigned char, 1, void);
109struct kfifo_rec_ptr_2 __STRUCT_KFIFO_PTR(unsigned char, 2, void);
110
111/*
112 * helper macro to distinguish between real in place fifo where the fifo
113 * array is a part of the structure and the fifo type where the array is
114 * outside of the fifo structure.
115 */
116#define __is_kfifo_ptr(fifo) \
117 (sizeof(*fifo) == sizeof(STRUCT_KFIFO_PTR(typeof(*(fifo)->type))))
118
119/**
120 * DECLARE_KFIFO_PTR - macro to declare a fifo pointer object
121 * @fifo: name of the declared fifo
122 * @type: type of the fifo elements
123 */
124#define DECLARE_KFIFO_PTR(fifo, type) STRUCT_KFIFO_PTR(type) fifo
125
126/**
127 * DECLARE_KFIFO - macro to declare a fifo object
128 * @fifo: name of the declared fifo
129 * @type: type of the fifo elements
130 * @size: the number of elements in the fifo, this must be a power of 2
131 */
132#define DECLARE_KFIFO(fifo, type, size) STRUCT_KFIFO(type, size) fifo
133
134/**
135 * INIT_KFIFO - Initialize a fifo declared by DECLARE_KFIFO
136 * @fifo: name of the declared fifo datatype
137 */
138#define INIT_KFIFO(fifo) \
139(void)({ \
140 typeof(&(fifo)) __tmp = &(fifo); \
141 struct __kfifo *__kfifo = &__tmp->kfifo; \
142 __kfifo->in = 0; \
143 __kfifo->out = 0; \
144 __kfifo->mask = __is_kfifo_ptr(__tmp) ? 0 : ARRAY_SIZE(__tmp->buf) - 1;\
145 __kfifo->esize = sizeof(*__tmp->buf); \
146 __kfifo->data = __is_kfifo_ptr(__tmp) ? NULL : __tmp->buf; \
147})
148
149/**
150 * DEFINE_KFIFO - macro to define and initialize a fifo
151 * @fifo: name of the declared fifo datatype
152 * @type: type of the fifo elements
153 * @size: the number of elements in the fifo, this must be a power of 2
154 *
155 * Note: the macro can be used for global and local fifo data type variables.
156 */
157#define DEFINE_KFIFO(fifo, type, size) \
158 DECLARE_KFIFO(fifo, type, size) = \
159 (typeof(fifo)) { \
160 { \
161 { \
162 .in = 0, \
163 .out = 0, \
164 .mask = __is_kfifo_ptr(&(fifo)) ? \
165 0 : \
166 ARRAY_SIZE((fifo).buf) - 1, \
167 .esize = sizeof(*(fifo).buf), \
168 .data = __is_kfifo_ptr(&(fifo)) ? \
169 NULL : \
170 (fifo).buf, \
171 } \
172 } \
173 }
174
175
176static inline unsigned int __must_check
177__kfifo_uint_must_check_helper(unsigned int val)
178{
179 return val;
180}
181
182static inline int __must_check
183__kfifo_int_must_check_helper(int val)
184{
185 return val;
186}
187
188/**
189 * kfifo_initialized - Check if the fifo is initialized
190 * @fifo: address of the fifo to check
191 *
192 * Return %true if fifo is initialized, otherwise %false.
193 * Assumes the fifo was 0 before.
194 */
195#define kfifo_initialized(fifo) ((fifo)->kfifo.mask)
196
197/**
198 * kfifo_esize - returns the size of the element managed by the fifo
199 * @fifo: address of the fifo to be used
200 */
201#define kfifo_esize(fifo) ((fifo)->kfifo.esize)
202
203/**
204 * kfifo_recsize - returns the size of the record length field
205 * @fifo: address of the fifo to be used
206 */
207#define kfifo_recsize(fifo) (sizeof(*(fifo)->rectype))
208
209/**
210 * kfifo_size - returns the size of the fifo in elements
211 * @fifo: address of the fifo to be used
212 */
213#define kfifo_size(fifo) ((fifo)->kfifo.mask + 1)
214
215/**
216 * kfifo_reset - removes the entire fifo content
217 * @fifo: address of the fifo to be used
218 *
219 * Note: usage of kfifo_reset() is dangerous. It should be only called when the
220 * fifo is exclusived locked or when it is secured that no other thread is
221 * accessing the fifo.
222 */
223#define kfifo_reset(fifo) \
224(void)({ \
225 typeof((fifo) + 1) __tmp = (fifo); \
226 __tmp->kfifo.in = __tmp->kfifo.out = 0; \
227})
228
229/**
230 * kfifo_reset_out - skip fifo content
231 * @fifo: address of the fifo to be used
232 *
233 * Note: The usage of kfifo_reset_out() is safe until it will be only called
234 * from the reader thread and there is only one concurrent reader. Otherwise
235 * it is dangerous and must be handled in the same way as kfifo_reset().
236 */
237#define kfifo_reset_out(fifo) \
238(void)({ \
239 typeof((fifo) + 1) __tmp = (fifo); \
240 __tmp->kfifo.out = __tmp->kfifo.in; \
241})
242
243/**
244 * kfifo_len - returns the number of used elements in the fifo
245 * @fifo: address of the fifo to be used
246 */
247#define kfifo_len(fifo) \
248({ \
249 typeof((fifo) + 1) __tmpl = (fifo); \
250 __tmpl->kfifo.in - __tmpl->kfifo.out; \
251})
252
253/**
254 * kfifo_is_empty - returns true if the fifo is empty
255 * @fifo: address of the fifo to be used
256 */
257#define kfifo_is_empty(fifo) \
258({ \
259 typeof((fifo) + 1) __tmpq = (fifo); \
260 __tmpq->kfifo.in == __tmpq->kfifo.out; \
261})
262
263/**
264 * kfifo_is_full - returns true if the fifo is full
265 * @fifo: address of the fifo to be used
266 */
267#define kfifo_is_full(fifo) \
268({ \
269 typeof((fifo) + 1) __tmpq = (fifo); \
270 kfifo_len(__tmpq) > __tmpq->kfifo.mask; \
271})
272
273/**
274 * kfifo_avail - returns the number of unused elements in the fifo
275 * @fifo: address of the fifo to be used
276 */
277#define kfifo_avail(fifo) \
278__kfifo_uint_must_check_helper( \
279({ \
280 typeof((fifo) + 1) __tmpq = (fifo); \
281 const size_t __recsize = sizeof(*__tmpq->rectype); \
282 unsigned int __avail = kfifo_size(__tmpq) - kfifo_len(__tmpq); \
283 (__recsize) ? ((__avail <= __recsize) ? 0 : \
284 __kfifo_max_r(__avail - __recsize, __recsize)) : \
285 __avail; \
286}) \
287)
288
289/**
290 * kfifo_skip - skip output data
291 * @fifo: address of the fifo to be used
292 */
293#define kfifo_skip(fifo) \
294(void)({ \
295 typeof((fifo) + 1) __tmp = (fifo); \
296 const size_t __recsize = sizeof(*__tmp->rectype); \
297 struct __kfifo *__kfifo = &__tmp->kfifo; \
298 if (__recsize) \
299 __kfifo_skip_r(__kfifo, __recsize); \
300 else \
301 __kfifo->out++; \
302})
303
304/**
305 * kfifo_peek_len - gets the size of the next fifo record
306 * @fifo: address of the fifo to be used
307 *
308 * This function returns the size of the next fifo record in number of bytes.
309 */
310#define kfifo_peek_len(fifo) \
311__kfifo_uint_must_check_helper( \
312({ \
313 typeof((fifo) + 1) __tmp = (fifo); \
314 const size_t __recsize = sizeof(*__tmp->rectype); \
315 struct __kfifo *__kfifo = &__tmp->kfifo; \
316 (!__recsize) ? kfifo_len(__tmp) * sizeof(*__tmp->type) : \
317 __kfifo_len_r(__kfifo, __recsize); \
318}) \
319)
320
321/**
322 * kfifo_alloc - dynamically allocates a new fifo buffer
323 * @fifo: pointer to the fifo
324 * @size: the number of elements in the fifo, this must be a power of 2
325 * @gfp_mask: get_free_pages mask, passed to kmalloc()
326 *
327 * This macro dynamically allocates a new fifo buffer.
328 *
329 * The number of elements will be rounded-up to a power of 2.
330 * The fifo will be release with kfifo_free().
331 * Return 0 if no error, otherwise an error code.
332 */
333#define kfifo_alloc(fifo, size, gfp_mask) \
334__kfifo_int_must_check_helper( \
335({ \
336 typeof((fifo) + 1) __tmp = (fifo); \
337 struct __kfifo *__kfifo = &__tmp->kfifo; \
338 __is_kfifo_ptr(__tmp) ? \
339 __kfifo_alloc(__kfifo, size, sizeof(*__tmp->type), gfp_mask) : \
340 -EINVAL; \
341}) \
342)
343
344/**
345 * kfifo_free - frees the fifo
346 * @fifo: the fifo to be freed
347 */
348#define kfifo_free(fifo) \
349({ \
350 typeof((fifo) + 1) __tmp = (fifo); \
351 struct __kfifo *__kfifo = &__tmp->kfifo; \
352 if (__is_kfifo_ptr(__tmp)) \
353 __kfifo_free(__kfifo); \
354})
355
356/**
357 * kfifo_init - initialize a fifo using a preallocated buffer
358 * @fifo: the fifo to assign the buffer
359 * @buffer: the preallocated buffer to be used
360 * @size: the size of the internal buffer, this have to be a power of 2
361 *
362 * This macro initializes a fifo using a preallocated buffer.
363 *
364 * The number of elements will be rounded-up to a power of 2.
365 * Return 0 if no error, otherwise an error code.
366 */
367#define kfifo_init(fifo, buffer, size) \
368({ \
369 typeof((fifo) + 1) __tmp = (fifo); \
370 struct __kfifo *__kfifo = &__tmp->kfifo; \
371 __is_kfifo_ptr(__tmp) ? \
372 __kfifo_init(__kfifo, buffer, size, sizeof(*__tmp->type)) : \
373 -EINVAL; \
374})
375
376/**
377 * kfifo_put - put data into the fifo
378 * @fifo: address of the fifo to be used
379 * @val: the data to be added
380 *
381 * This macro copies the given value into the fifo.
382 * It returns 0 if the fifo was full. Otherwise it returns the number
383 * processed elements.
384 *
385 * Note that with only one concurrent reader and one concurrent
386 * writer, you don't need extra locking to use these macro.
387 */
388#define kfifo_put(fifo, val) \
389({ \
390 typeof((fifo) + 1) __tmp = (fifo); \
391 typeof(*__tmp->const_type) __val = (val); \
392 unsigned int __ret; \
393 size_t __recsize = sizeof(*__tmp->rectype); \
394 struct __kfifo *__kfifo = &__tmp->kfifo; \
395 if (__recsize) \
396 __ret = __kfifo_in_r(__kfifo, &__val, sizeof(__val), \
397 __recsize); \
398 else { \
399 __ret = !kfifo_is_full(__tmp); \
400 if (__ret) { \
401 (__is_kfifo_ptr(__tmp) ? \
402 ((typeof(__tmp->type))__kfifo->data) : \
403 (__tmp->buf) \
404 )[__kfifo->in & __tmp->kfifo.mask] = \
405 *(typeof(__tmp->type))&__val; \
406 smp_wmb(); \
407 __kfifo->in++; \
408 } \
409 } \
410 __ret; \
411})
412
413/**
414 * kfifo_get - get data from the fifo
415 * @fifo: address of the fifo to be used
416 * @val: address where to store the data
417 *
418 * This macro reads the data from the fifo.
419 * It returns 0 if the fifo was empty. Otherwise it returns the number
420 * processed elements.
421 *
422 * Note that with only one concurrent reader and one concurrent
423 * writer, you don't need extra locking to use these macro.
424 */
425#define kfifo_get(fifo, val) \
426__kfifo_uint_must_check_helper( \
427({ \
428 typeof((fifo) + 1) __tmp = (fifo); \
429 typeof(__tmp->ptr) __val = (val); \
430 unsigned int __ret; \
431 const size_t __recsize = sizeof(*__tmp->rectype); \
432 struct __kfifo *__kfifo = &__tmp->kfifo; \
433 if (__recsize) \
434 __ret = __kfifo_out_r(__kfifo, __val, sizeof(*__val), \
435 __recsize); \
436 else { \
437 __ret = !kfifo_is_empty(__tmp); \
438 if (__ret) { \
439 *(typeof(__tmp->type))__val = \
440 (__is_kfifo_ptr(__tmp) ? \
441 ((typeof(__tmp->type))__kfifo->data) : \
442 (__tmp->buf) \
443 )[__kfifo->out & __tmp->kfifo.mask]; \
444 smp_wmb(); \
445 __kfifo->out++; \
446 } \
447 } \
448 __ret; \
449}) \
450)
451
452/**
453 * kfifo_peek - get data from the fifo without removing
454 * @fifo: address of the fifo to be used
455 * @val: address where to store the data
456 *
457 * This reads the data from the fifo without removing it from the fifo.
458 * It returns 0 if the fifo was empty. Otherwise it returns the number
459 * processed elements.
460 *
461 * Note that with only one concurrent reader and one concurrent
462 * writer, you don't need extra locking to use these macro.
463 */
464#define kfifo_peek(fifo, val) \
465__kfifo_uint_must_check_helper( \
466({ \
467 typeof((fifo) + 1) __tmp = (fifo); \
468 typeof(__tmp->ptr) __val = (val); \
469 unsigned int __ret; \
470 const size_t __recsize = sizeof(*__tmp->rectype); \
471 struct __kfifo *__kfifo = &__tmp->kfifo; \
472 if (__recsize) \
473 __ret = __kfifo_out_peek_r(__kfifo, __val, sizeof(*__val), \
474 __recsize); \
475 else { \
476 __ret = !kfifo_is_empty(__tmp); \
477 if (__ret) { \
478 *(typeof(__tmp->type))__val = \
479 (__is_kfifo_ptr(__tmp) ? \
480 ((typeof(__tmp->type))__kfifo->data) : \
481 (__tmp->buf) \
482 )[__kfifo->out & __tmp->kfifo.mask]; \
483 smp_wmb(); \
484 } \
485 } \
486 __ret; \
487}) \
488)
489
490/**
491 * kfifo_in - put data into the fifo
492 * @fifo: address of the fifo to be used
493 * @buf: the data to be added
494 * @n: number of elements to be added
495 *
496 * This macro copies the given buffer into the fifo and returns the
497 * number of copied elements.
498 *
499 * Note that with only one concurrent reader and one concurrent
500 * writer, you don't need extra locking to use these macro.
501 */
502#define kfifo_in(fifo, buf, n) \
503({ \
504 typeof((fifo) + 1) __tmp = (fifo); \
505 typeof(__tmp->ptr_const) __buf = (buf); \
506 unsigned long __n = (n); \
507 const size_t __recsize = sizeof(*__tmp->rectype); \
508 struct __kfifo *__kfifo = &__tmp->kfifo; \
509 (__recsize) ?\
510 __kfifo_in_r(__kfifo, __buf, __n, __recsize) : \
511 __kfifo_in(__kfifo, __buf, __n); \
512})
513
514/**
515 * kfifo_in_spinlocked - put data into the fifo using a spinlock for locking
516 * @fifo: address of the fifo to be used
517 * @buf: the data to be added
518 * @n: number of elements to be added
519 * @lock: pointer to the spinlock to use for locking
520 *
521 * This macro copies the given values buffer into the fifo and returns the
522 * number of copied elements.
523 */
524#define kfifo_in_spinlocked(fifo, buf, n, lock) \
525({ \
526 unsigned long __flags; \
527 unsigned int __ret; \
528 spin_lock_irqsave(lock, __flags); \
529 __ret = kfifo_in(fifo, buf, n); \
530 spin_unlock_irqrestore(lock, __flags); \
531 __ret; \
532})
533
534/* alias for kfifo_in_spinlocked, will be removed in a future release */
535#define kfifo_in_locked(fifo, buf, n, lock) \
536 kfifo_in_spinlocked(fifo, buf, n, lock)
537
538/**
539 * kfifo_out - get data from the fifo
540 * @fifo: address of the fifo to be used
541 * @buf: pointer to the storage buffer
542 * @n: max. number of elements to get
543 *
544 * This macro get some data from the fifo and return the numbers of elements
545 * copied.
546 *
547 * Note that with only one concurrent reader and one concurrent
548 * writer, you don't need extra locking to use these macro.
549 */
550#define kfifo_out(fifo, buf, n) \
551__kfifo_uint_must_check_helper( \
552({ \
553 typeof((fifo) + 1) __tmp = (fifo); \
554 typeof(__tmp->ptr) __buf = (buf); \
555 unsigned long __n = (n); \
556 const size_t __recsize = sizeof(*__tmp->rectype); \
557 struct __kfifo *__kfifo = &__tmp->kfifo; \
558 (__recsize) ?\
559 __kfifo_out_r(__kfifo, __buf, __n, __recsize) : \
560 __kfifo_out(__kfifo, __buf, __n); \
561}) \
562)
563
564/**
565 * kfifo_out_spinlocked - get data from the fifo using a spinlock for locking
566 * @fifo: address of the fifo to be used
567 * @buf: pointer to the storage buffer
568 * @n: max. number of elements to get
569 * @lock: pointer to the spinlock to use for locking
570 *
571 * This macro get the data from the fifo and return the numbers of elements
572 * copied.
573 */
574#define kfifo_out_spinlocked(fifo, buf, n, lock) \
575__kfifo_uint_must_check_helper( \
576({ \
577 unsigned long __flags; \
578 unsigned int __ret; \
579 spin_lock_irqsave(lock, __flags); \
580 __ret = kfifo_out(fifo, buf, n); \
581 spin_unlock_irqrestore(lock, __flags); \
582 __ret; \
583}) \
584)
585
586/* alias for kfifo_out_spinlocked, will be removed in a future release */
587#define kfifo_out_locked(fifo, buf, n, lock) \
588 kfifo_out_spinlocked(fifo, buf, n, lock)
589
590/**
591 * kfifo_from_user - puts some data from user space into the fifo
592 * @fifo: address of the fifo to be used
593 * @from: pointer to the data to be added
594 * @len: the length of the data to be added
595 * @copied: pointer to output variable to store the number of copied bytes
596 *
597 * This macro copies at most @len bytes from the @from into the
598 * fifo, depending of the available space and returns -EFAULT/0.
599 *
600 * Note that with only one concurrent reader and one concurrent
601 * writer, you don't need extra locking to use these macro.
602 */
603#define kfifo_from_user(fifo, from, len, copied) \
604__kfifo_uint_must_check_helper( \
605({ \
606 typeof((fifo) + 1) __tmp = (fifo); \
607 const void __user *__from = (from); \
608 unsigned int __len = (len); \
609 unsigned int *__copied = (copied); \
610 const size_t __recsize = sizeof(*__tmp->rectype); \
611 struct __kfifo *__kfifo = &__tmp->kfifo; \
612 (__recsize) ? \
613 __kfifo_from_user_r(__kfifo, __from, __len, __copied, __recsize) : \
614 __kfifo_from_user(__kfifo, __from, __len, __copied); \
615}) \
616)
617
618/**
619 * kfifo_to_user - copies data from the fifo into user space
620 * @fifo: address of the fifo to be used
621 * @to: where the data must be copied
622 * @len: the size of the destination buffer
623 * @copied: pointer to output variable to store the number of copied bytes
624 *
625 * This macro copies at most @len bytes from the fifo into the
626 * @to buffer and returns -EFAULT/0.
627 *
628 * Note that with only one concurrent reader and one concurrent
629 * writer, you don't need extra locking to use these macro.
630 */
631#define kfifo_to_user(fifo, to, len, copied) \
632__kfifo_uint_must_check_helper( \
633({ \
634 typeof((fifo) + 1) __tmp = (fifo); \
635 void __user *__to = (to); \
636 unsigned int __len = (len); \
637 unsigned int *__copied = (copied); \
638 const size_t __recsize = sizeof(*__tmp->rectype); \
639 struct __kfifo *__kfifo = &__tmp->kfifo; \
640 (__recsize) ? \
641 __kfifo_to_user_r(__kfifo, __to, __len, __copied, __recsize) : \
642 __kfifo_to_user(__kfifo, __to, __len, __copied); \
643}) \
644)
645
646/**
647 * kfifo_dma_in_prepare - setup a scatterlist for DMA input
648 * @fifo: address of the fifo to be used
649 * @sgl: pointer to the scatterlist array
650 * @nents: number of entries in the scatterlist array
651 * @len: number of elements to transfer
652 *
653 * This macro fills a scatterlist for DMA input.
654 * It returns the number entries in the scatterlist array.
655 *
656 * Note that with only one concurrent reader and one concurrent
657 * writer, you don't need extra locking to use these macros.
658 */
659#define kfifo_dma_in_prepare(fifo, sgl, nents, len) \
660({ \
661 typeof((fifo) + 1) __tmp = (fifo); \
662 struct scatterlist *__sgl = (sgl); \
663 int __nents = (nents); \
664 unsigned int __len = (len); \
665 const size_t __recsize = sizeof(*__tmp->rectype); \
666 struct __kfifo *__kfifo = &__tmp->kfifo; \
667 (__recsize) ? \
668 __kfifo_dma_in_prepare_r(__kfifo, __sgl, __nents, __len, __recsize) : \
669 __kfifo_dma_in_prepare(__kfifo, __sgl, __nents, __len); \
670})
671
672/**
673 * kfifo_dma_in_finish - finish a DMA IN operation
674 * @fifo: address of the fifo to be used
675 * @len: number of bytes to received
676 *
677 * This macro finish a DMA IN operation. The in counter will be updated by
678 * the len parameter. No error checking will be done.
679 *
680 * Note that with only one concurrent reader and one concurrent
681 * writer, you don't need extra locking to use these macros.
682 */
683#define kfifo_dma_in_finish(fifo, len) \
684(void)({ \
685 typeof((fifo) + 1) __tmp = (fifo); \
686 unsigned int __len = (len); \
687 const size_t __recsize = sizeof(*__tmp->rectype); \
688 struct __kfifo *__kfifo = &__tmp->kfifo; \
689 if (__recsize) \
690 __kfifo_dma_in_finish_r(__kfifo, __len, __recsize); \
691 else \
692 __kfifo->in += __len / sizeof(*__tmp->type); \
693})
694
695/**
696 * kfifo_dma_out_prepare - setup a scatterlist for DMA output
697 * @fifo: address of the fifo to be used
698 * @sgl: pointer to the scatterlist array
699 * @nents: number of entries in the scatterlist array
700 * @len: number of elements to transfer
701 *
702 * This macro fills a scatterlist for DMA output which at most @len bytes
703 * to transfer.
704 * It returns the number entries in the scatterlist array.
705 * A zero means there is no space available and the scatterlist is not filled.
706 *
707 * Note that with only one concurrent reader and one concurrent
708 * writer, you don't need extra locking to use these macros.
709 */
710#define kfifo_dma_out_prepare(fifo, sgl, nents, len) \
711({ \
712 typeof((fifo) + 1) __tmp = (fifo); \
713 struct scatterlist *__sgl = (sgl); \
714 int __nents = (nents); \
715 unsigned int __len = (len); \
716 const size_t __recsize = sizeof(*__tmp->rectype); \
717 struct __kfifo *__kfifo = &__tmp->kfifo; \
718 (__recsize) ? \
719 __kfifo_dma_out_prepare_r(__kfifo, __sgl, __nents, __len, __recsize) : \
720 __kfifo_dma_out_prepare(__kfifo, __sgl, __nents, __len); \
721})
722
723/**
724 * kfifo_dma_out_finish - finish a DMA OUT operation
725 * @fifo: address of the fifo to be used
726 * @len: number of bytes transferred
727 *
728 * This macro finish a DMA OUT operation. The out counter will be updated by
729 * the len parameter. No error checking will be done.
730 *
731 * Note that with only one concurrent reader and one concurrent
732 * writer, you don't need extra locking to use these macros.
733 */
734#define kfifo_dma_out_finish(fifo, len) \
735(void)({ \
736 typeof((fifo) + 1) __tmp = (fifo); \
737 unsigned int __len = (len); \
738 const size_t __recsize = sizeof(*__tmp->rectype); \
739 struct __kfifo *__kfifo = &__tmp->kfifo; \
740 if (__recsize) \
741 __kfifo_dma_out_finish_r(__kfifo, __recsize); \
742 else \
743 __kfifo->out += __len / sizeof(*__tmp->type); \
744})
745
746/**
747 * kfifo_out_peek - gets some data from the fifo
748 * @fifo: address of the fifo to be used
749 * @buf: pointer to the storage buffer
750 * @n: max. number of elements to get
751 *
752 * This macro get the data from the fifo and return the numbers of elements
753 * copied. The data is not removed from the fifo.
754 *
755 * Note that with only one concurrent reader and one concurrent
756 * writer, you don't need extra locking to use these macro.
757 */
758#define kfifo_out_peek(fifo, buf, n) \
759__kfifo_uint_must_check_helper( \
760({ \
761 typeof((fifo) + 1) __tmp = (fifo); \
762 typeof(__tmp->ptr) __buf = (buf); \
763 unsigned long __n = (n); \
764 const size_t __recsize = sizeof(*__tmp->rectype); \
765 struct __kfifo *__kfifo = &__tmp->kfifo; \
766 (__recsize) ? \
767 __kfifo_out_peek_r(__kfifo, __buf, __n, __recsize) : \
768 __kfifo_out_peek(__kfifo, __buf, __n); \
769}) \
770)
771
772extern int __kfifo_alloc(struct __kfifo *fifo, unsigned int size,
773 size_t esize, gfp_t gfp_mask);
774
775extern void __kfifo_free(struct __kfifo *fifo);
776
777extern int __kfifo_init(struct __kfifo *fifo, void *buffer,
778 unsigned int size, size_t esize);
779
780extern unsigned int __kfifo_in(struct __kfifo *fifo,
781 const void *buf, unsigned int len);
782
783extern unsigned int __kfifo_out(struct __kfifo *fifo,
784 void *buf, unsigned int len);
785
786extern int __kfifo_from_user(struct __kfifo *fifo,
787 const void __user *from, unsigned long len, unsigned int *copied);
788
789extern int __kfifo_to_user(struct __kfifo *fifo,
790 void __user *to, unsigned long len, unsigned int *copied);
791
792extern unsigned int __kfifo_dma_in_prepare(struct __kfifo *fifo,
793 struct scatterlist *sgl, int nents, unsigned int len);
794
795extern unsigned int __kfifo_dma_out_prepare(struct __kfifo *fifo,
796 struct scatterlist *sgl, int nents, unsigned int len);
797
798extern unsigned int __kfifo_out_peek(struct __kfifo *fifo,
799 void *buf, unsigned int len);
800
801extern unsigned int __kfifo_in_r(struct __kfifo *fifo,
802 const void *buf, unsigned int len, size_t recsize);
803
804extern unsigned int __kfifo_out_r(struct __kfifo *fifo,
805 void *buf, unsigned int len, size_t recsize);
806
807extern int __kfifo_from_user_r(struct __kfifo *fifo,
808 const void __user *from, unsigned long len, unsigned int *copied,
809 size_t recsize);
810
811extern int __kfifo_to_user_r(struct __kfifo *fifo, void __user *to,
812 unsigned long len, unsigned int *copied, size_t recsize);
813
814extern unsigned int __kfifo_dma_in_prepare_r(struct __kfifo *fifo,
815 struct scatterlist *sgl, int nents, unsigned int len, size_t recsize);
816
817extern void __kfifo_dma_in_finish_r(struct __kfifo *fifo,
818 unsigned int len, size_t recsize);
819
820extern unsigned int __kfifo_dma_out_prepare_r(struct __kfifo *fifo,
821 struct scatterlist *sgl, int nents, unsigned int len, size_t recsize);
822
823extern void __kfifo_dma_out_finish_r(struct __kfifo *fifo, size_t recsize);
824
825extern unsigned int __kfifo_len_r(struct __kfifo *fifo, size_t recsize);
826
827extern void __kfifo_skip_r(struct __kfifo *fifo, size_t recsize);
828
829extern unsigned int __kfifo_out_peek_r(struct __kfifo *fifo,
830 void *buf, unsigned int len, size_t recsize);
831
832extern unsigned int __kfifo_max_r(unsigned int len, size_t recsize);
833
834#endif
835