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1da177e4 | 1 | /* |
2e956fb3 | 2 | * A generic kernel FIFO implementation |
1da177e4 | 3 | * |
498d319b | 4 | * Copyright (C) 2013 Stefani Seibold <stefani@seibold.net> |
1da177e4 LT |
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 | */ | |
7acd72eb | 21 | |
2e956fb3 SS |
22 | #ifndef _LINUX_KFIFO_H |
23 | #define _LINUX_KFIFO_H | |
24 | ||
7acd72eb | 25 | /* |
2e956fb3 | 26 | * How to porting drivers to the new generic FIFO API: |
7acd72eb SS |
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 | |
2e956fb3 SS |
35 | * - Replace the use of kfifo_put into kfifo_in_spinlocked and kfifo_get |
36 | * into kfifo_out_spinlocked | |
7acd72eb | 37 | * Note: the spinlock pointer formerly passed to kfifo_init/kfifo_alloc |
2e956fb3 SS |
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_* | |
7acd72eb SS |
41 | */ |
42 | ||
2e956fb3 | 43 | /* |
de99626c VV |
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 | |
2e956fb3 | 47 | * in the reader thread. |
de99626c | 48 | * For multiple writer and one reader there is only a need to lock the writer. |
2e956fb3 SS |
49 | * And vice versa for only one writer and multiple reader there is only a need |
50 | * to lock the reader. | |
51 | */ | |
1da177e4 | 52 | |
1da177e4 LT |
53 | #include <linux/kernel.h> |
54 | #include <linux/spinlock.h> | |
2e956fb3 SS |
55 | #include <linux/stddef.h> |
56 | #include <linux/scatterlist.h> | |
57 | ||
58 | struct __kfifo { | |
59 | unsigned int in; | |
60 | unsigned int out; | |
61 | unsigned int mask; | |
62 | unsigned int esize; | |
63 | void *data; | |
1da177e4 LT |
64 | }; |
65 | ||
2e956fb3 SS |
66 | #define __STRUCT_KFIFO_COMMON(datatype, recsize, ptrtype) \ |
67 | union { \ | |
68 | struct __kfifo kfifo; \ | |
69 | datatype *type; \ | |
498d319b | 70 | const datatype *const_type; \ |
2e956fb3 SS |
71 | char (*rectype)[recsize]; \ |
72 | ptrtype *ptr; \ | |
498d319b | 73 | ptrtype const *ptr_const; \ |
37bdfbbf SS |
74 | } |
75 | ||
2e956fb3 SS |
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]; \ | |
37bdfbbf SS |
80 | } |
81 | ||
2e956fb3 SS |
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 | |
37bdfbbf | 96 | */ |
2e956fb3 | 97 | struct kfifo __STRUCT_KFIFO_PTR(unsigned char, 0, void); |
37bdfbbf | 98 | |
2e956fb3 SS |
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 | |
37bdfbbf | 107 | */ |
2e956fb3 SS |
108 | struct kfifo_rec_ptr_1 __STRUCT_KFIFO_PTR(unsigned char, 1, void); |
109 | struct kfifo_rec_ptr_2 __STRUCT_KFIFO_PTR(unsigned char, 2, void); | |
37bdfbbf | 110 | |
2e956fb3 SS |
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 | */ | |
8a866fee SY |
116 | #define __is_kfifo_ptr(fifo) \ |
117 | (sizeof(*fifo) == sizeof(STRUCT_KFIFO_PTR(typeof(*(fifo)->type)))) | |
a5b9e2c1 | 118 | |
d994ffc2 | 119 | /** |
2e956fb3 SS |
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 | |
d994ffc2 | 123 | */ |
2e956fb3 | 124 | #define DECLARE_KFIFO_PTR(fifo, type) STRUCT_KFIFO_PTR(type) fifo |
1da177e4 | 125 | |
1da177e4 | 126 | /** |
2e956fb3 SS |
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 | |
1da177e4 | 131 | */ |
2e956fb3 | 132 | #define DECLARE_KFIFO(fifo, type, size) STRUCT_KFIFO(type, size) fifo |
c1e13f25 | 133 | |
a121f24a | 134 | /** |
2e956fb3 SS |
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 | }) | |
a121f24a | 148 | |
37bdfbbf | 149 | /** |
2e956fb3 SS |
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 | ||
144ecf31 SS |
176 | static inline unsigned int __must_check |
177 | __kfifo_uint_must_check_helper(unsigned int val) | |
178 | { | |
179 | return val; | |
180 | } | |
181 | ||
182 | static inline int __must_check | |
183 | __kfifo_int_must_check_helper(int val) | |
184 | { | |
185 | return val; | |
186 | } | |
37bdfbbf | 187 | |
c1e13f25 | 188 | /** |
2e956fb3 SS |
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. | |
c1e13f25 | 194 | */ |
2e956fb3 | 195 | #define kfifo_initialized(fifo) ((fifo)->kfifo.mask) |
1da177e4 | 196 | |
37bdfbbf | 197 | /** |
2e956fb3 SS |
198 | * kfifo_esize - returns the size of the element managed by the fifo |
199 | * @fifo: address of the fifo to be used | |
37bdfbbf | 200 | */ |
2e956fb3 | 201 | #define kfifo_esize(fifo) ((fifo)->kfifo.esize) |
37bdfbbf SS |
202 | |
203 | /** | |
2e956fb3 SS |
204 | * kfifo_recsize - returns the size of the record length field |
205 | * @fifo: address of the fifo to be used | |
37bdfbbf | 206 | */ |
2e956fb3 | 207 | #define kfifo_recsize(fifo) (sizeof(*(fifo)->rectype)) |
37bdfbbf SS |
208 | |
209 | /** | |
2e956fb3 SS |
210 | * kfifo_size - returns the size of the fifo in elements |
211 | * @fifo: address of the fifo to be used | |
37bdfbbf | 212 | */ |
2e956fb3 | 213 | #define kfifo_size(fifo) ((fifo)->kfifo.mask + 1) |
37bdfbbf | 214 | |
1da177e4 | 215 | /** |
2e956fb3 SS |
216 | * kfifo_reset - removes the entire fifo content |
217 | * @fifo: address of the fifo to be used | |
1da177e4 | 218 | * |
2e956fb3 SS |
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. | |
1da177e4 | 222 | */ |
2e956fb3 SS |
223 | #define kfifo_reset(fifo) \ |
224 | (void)({ \ | |
e0bf1024 | 225 | typeof((fifo) + 1) __tmp = (fifo); \ |
2e956fb3 SS |
226 | __tmp->kfifo.in = __tmp->kfifo.out = 0; \ |
227 | }) | |
1da177e4 LT |
228 | |
229 | /** | |
2e956fb3 SS |
230 | * kfifo_reset_out - skip fifo content |
231 | * @fifo: address of the fifo to be used | |
1da177e4 | 232 | * |
2e956fb3 SS |
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(). | |
a121f24a | 236 | */ |
2e956fb3 SS |
237 | #define kfifo_reset_out(fifo) \ |
238 | (void)({ \ | |
e0bf1024 | 239 | typeof((fifo) + 1) __tmp = (fifo); \ |
2e956fb3 SS |
240 | __tmp->kfifo.out = __tmp->kfifo.in; \ |
241 | }) | |
a121f24a | 242 | |
2e956fb3 SS |
243 | /** |
244 | * kfifo_len - returns the number of used elements in the fifo | |
245 | * @fifo: address of the fifo to be used | |
a121f24a | 246 | */ |
2e956fb3 SS |
247 | #define kfifo_len(fifo) \ |
248 | ({ \ | |
e0bf1024 | 249 | typeof((fifo) + 1) __tmpl = (fifo); \ |
2e956fb3 SS |
250 | __tmpl->kfifo.in - __tmpl->kfifo.out; \ |
251 | }) | |
a121f24a | 252 | |
2e956fb3 SS |
253 | /** |
254 | * kfifo_is_empty - returns true if the fifo is empty | |
255 | * @fifo: address of the fifo to be used | |
a121f24a | 256 | */ |
2e956fb3 SS |
257 | #define kfifo_is_empty(fifo) \ |
258 | ({ \ | |
e0bf1024 | 259 | typeof((fifo) + 1) __tmpq = (fifo); \ |
2e956fb3 SS |
260 | __tmpq->kfifo.in == __tmpq->kfifo.out; \ |
261 | }) | |
a121f24a | 262 | |
2e956fb3 SS |
263 | /** |
264 | * kfifo_is_full - returns true if the fifo is full | |
265 | * @fifo: address of the fifo to be used | |
86d48803 | 266 | */ |
2e956fb3 SS |
267 | #define kfifo_is_full(fifo) \ |
268 | ({ \ | |
e0bf1024 | 269 | typeof((fifo) + 1) __tmpq = (fifo); \ |
2e956fb3 SS |
270 | kfifo_len(__tmpq) > __tmpq->kfifo.mask; \ |
271 | }) | |
86d48803 | 272 | |
2e956fb3 SS |
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) \ | |
144ecf31 | 278 | __kfifo_uint_must_check_helper( \ |
2e956fb3 | 279 | ({ \ |
e0bf1024 | 280 | typeof((fifo) + 1) __tmpq = (fifo); \ |
2e956fb3 SS |
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 | ) | |
86d48803 | 288 | |
2e956fb3 SS |
289 | /** |
290 | * kfifo_skip - skip output data | |
291 | * @fifo: address of the fifo to be used | |
292 | */ | |
293 | #define kfifo_skip(fifo) \ | |
294 | (void)({ \ | |
e0bf1024 | 295 | typeof((fifo) + 1) __tmp = (fifo); \ |
2e956fb3 SS |
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 | }) | |
86d48803 | 303 | |
2e956fb3 SS |
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) \ | |
144ecf31 | 311 | __kfifo_uint_must_check_helper( \ |
2e956fb3 | 312 | ({ \ |
e0bf1024 | 313 | typeof((fifo) + 1) __tmp = (fifo); \ |
2e956fb3 SS |
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 | ) | |
86d48803 | 320 | |
2e956fb3 SS |
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 | * | |
24d654fa | 329 | * The number of elements will be rounded-up to a power of 2. |
2e956fb3 SS |
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) \ | |
144ecf31 | 334 | __kfifo_int_must_check_helper( \ |
2e956fb3 | 335 | ({ \ |
e0bf1024 | 336 | typeof((fifo) + 1) __tmp = (fifo); \ |
2e956fb3 SS |
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 | ) | |
86d48803 | 343 | |
2e956fb3 SS |
344 | /** |
345 | * kfifo_free - frees the fifo | |
346 | * @fifo: the fifo to be freed | |
86d48803 | 347 | */ |
2e956fb3 SS |
348 | #define kfifo_free(fifo) \ |
349 | ({ \ | |
e0bf1024 | 350 | typeof((fifo) + 1) __tmp = (fifo); \ |
2e956fb3 SS |
351 | struct __kfifo *__kfifo = &__tmp->kfifo; \ |
352 | if (__is_kfifo_ptr(__tmp)) \ | |
353 | __kfifo_free(__kfifo); \ | |
354 | }) | |
86d48803 | 355 | |
2e956fb3 SS |
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 | * | |
24d654fa | 362 | * This macro initializes a fifo using a preallocated buffer. |
2e956fb3 | 363 | * |
24d654fa | 364 | * The number of elements will be rounded-up to a power of 2. |
2e956fb3 SS |
365 | * Return 0 if no error, otherwise an error code. |
366 | */ | |
367 | #define kfifo_init(fifo, buffer, size) \ | |
368 | ({ \ | |
e0bf1024 | 369 | typeof((fifo) + 1) __tmp = (fifo); \ |
2e956fb3 SS |
370 | struct __kfifo *__kfifo = &__tmp->kfifo; \ |
371 | __is_kfifo_ptr(__tmp) ? \ | |
372 | __kfifo_init(__kfifo, buffer, size, sizeof(*__tmp->type)) : \ | |
373 | -EINVAL; \ | |
374 | }) | |
86d48803 | 375 | |
2e956fb3 SS |
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 | ({ \ | |
e0bf1024 | 390 | typeof((fifo) + 1) __tmp = (fifo); \ |
498d319b | 391 | typeof(*__tmp->const_type) __val = (val); \ |
2e956fb3 | 392 | unsigned int __ret; \ |
498d319b | 393 | size_t __recsize = sizeof(*__tmp->rectype); \ |
2e956fb3 | 394 | struct __kfifo *__kfifo = &__tmp->kfifo; \ |
2e956fb3 | 395 | if (__recsize) \ |
498d319b | 396 | __ret = __kfifo_in_r(__kfifo, &__val, sizeof(__val), \ |
2e956fb3 SS |
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] = \ | |
21b2f443 | 405 | *(typeof(__tmp->type))&__val; \ |
2e956fb3 SS |
406 | smp_wmb(); \ |
407 | __kfifo->in++; \ | |
408 | } \ | |
409 | } \ | |
410 | __ret; \ | |
411 | }) | |
86d48803 | 412 | |
2e956fb3 SS |
413 | /** |
414 | * kfifo_get - get data from the fifo | |
415 | * @fifo: address of the fifo to be used | |
498d319b | 416 | * @val: address where to store the data |
2e956fb3 SS |
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) \ | |
144ecf31 | 426 | __kfifo_uint_must_check_helper( \ |
2e956fb3 | 427 | ({ \ |
e0bf1024 | 428 | typeof((fifo) + 1) __tmp = (fifo); \ |
498d319b | 429 | typeof(__tmp->ptr) __val = (val); \ |
2e956fb3 SS |
430 | unsigned int __ret; \ |
431 | const size_t __recsize = sizeof(*__tmp->rectype); \ | |
432 | struct __kfifo *__kfifo = &__tmp->kfifo; \ | |
2e956fb3 SS |
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 | ) | |
86d48803 | 451 | |
2e956fb3 SS |
452 | /** |
453 | * kfifo_peek - get data from the fifo without removing | |
454 | * @fifo: address of the fifo to be used | |
498d319b | 455 | * @val: address where to store the data |
2e956fb3 SS |
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) \ | |
144ecf31 | 465 | __kfifo_uint_must_check_helper( \ |
2e956fb3 | 466 | ({ \ |
e0bf1024 | 467 | typeof((fifo) + 1) __tmp = (fifo); \ |
498d319b | 468 | typeof(__tmp->ptr) __val = (val); \ |
2e956fb3 SS |
469 | unsigned int __ret; \ |
470 | const size_t __recsize = sizeof(*__tmp->rectype); \ | |
471 | struct __kfifo *__kfifo = &__tmp->kfifo; \ | |
2e956fb3 SS |
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 | ) | |
86d48803 | 489 | |
2e956fb3 SS |
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 | ({ \ | |
e0bf1024 | 504 | typeof((fifo) + 1) __tmp = (fifo); \ |
498d319b | 505 | typeof(__tmp->ptr_const) __buf = (buf); \ |
2e956fb3 SS |
506 | unsigned long __n = (n); \ |
507 | const size_t __recsize = sizeof(*__tmp->rectype); \ | |
508 | struct __kfifo *__kfifo = &__tmp->kfifo; \ | |
2e956fb3 SS |
509 | (__recsize) ?\ |
510 | __kfifo_in_r(__kfifo, __buf, __n, __recsize) : \ | |
511 | __kfifo_in(__kfifo, __buf, __n); \ | |
512 | }) | |
86d48803 | 513 | |
2e956fb3 SS |
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) | |
86d48803 | 537 | |
2e956fb3 SS |
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) \ | |
144ecf31 | 551 | __kfifo_uint_must_check_helper( \ |
2e956fb3 | 552 | ({ \ |
e0bf1024 | 553 | typeof((fifo) + 1) __tmp = (fifo); \ |
498d319b | 554 | typeof(__tmp->ptr) __buf = (buf); \ |
2e956fb3 SS |
555 | unsigned long __n = (n); \ |
556 | const size_t __recsize = sizeof(*__tmp->rectype); \ | |
557 | struct __kfifo *__kfifo = &__tmp->kfifo; \ | |
2e956fb3 SS |
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) \ | |
144ecf31 | 575 | __kfifo_uint_must_check_helper( \ |
2e956fb3 SS |
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) | |
86d48803 SS |
589 | |
590 | /** | |
2e956fb3 SS |
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 | |
86d48803 | 596 | * |
2e956fb3 SS |
597 | * This macro copies at most @len bytes from the @from into the |
598 | * fifo, depending of the available space and returns -EFAULT/0. | |
86d48803 SS |
599 | * |
600 | * Note that with only one concurrent reader and one concurrent | |
2e956fb3 SS |
601 | * writer, you don't need extra locking to use these macro. |
602 | */ | |
603 | #define kfifo_from_user(fifo, from, len, copied) \ | |
144ecf31 | 604 | __kfifo_uint_must_check_helper( \ |
2e956fb3 | 605 | ({ \ |
e0bf1024 | 606 | typeof((fifo) + 1) __tmp = (fifo); \ |
2e956fb3 SS |
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 | ) | |
86d48803 | 617 | |
2e956fb3 SS |
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) \ | |
144ecf31 | 632 | __kfifo_uint_must_check_helper( \ |
2e956fb3 | 633 | ({ \ |
e0bf1024 | 634 | typeof((fifo) + 1) __tmp = (fifo); \ |
2e956fb3 SS |
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 | ({ \ | |
e0bf1024 | 661 | typeof((fifo) + 1) __tmp = (fifo); \ |
2e956fb3 SS |
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 | }) | |
86d48803 | 671 | |
2e956fb3 SS |
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)({ \ | |
e0bf1024 | 685 | typeof((fifo) + 1) __tmp = (fifo); \ |
2e956fb3 SS |
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 | }) | |
86d48803 | 694 | |
2e956fb3 SS |
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 | ({ \ | |
e0bf1024 | 712 | typeof((fifo) + 1) __tmp = (fifo); \ |
2e956fb3 SS |
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 | }) | |
86d48803 | 722 | |
2e956fb3 SS |
723 | /** |
724 | * kfifo_dma_out_finish - finish a DMA OUT operation | |
725 | * @fifo: address of the fifo to be used | |
da3dae54 | 726 | * @len: number of bytes transferred |
2e956fb3 SS |
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)({ \ | |
e0bf1024 | 736 | typeof((fifo) + 1) __tmp = (fifo); \ |
2e956fb3 SS |
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 | }) | |
86d48803 SS |
745 | |
746 | /** | |
2e956fb3 SS |
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 | |
86d48803 | 751 | * |
2e956fb3 SS |
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. | |
86d48803 SS |
754 | * |
755 | * Note that with only one concurrent reader and one concurrent | |
2e956fb3 | 756 | * writer, you don't need extra locking to use these macro. |
86d48803 | 757 | */ |
2e956fb3 | 758 | #define kfifo_out_peek(fifo, buf, n) \ |
144ecf31 | 759 | __kfifo_uint_must_check_helper( \ |
2e956fb3 | 760 | ({ \ |
e0bf1024 | 761 | typeof((fifo) + 1) __tmp = (fifo); \ |
498d319b | 762 | typeof(__tmp->ptr) __buf = (buf); \ |
2e956fb3 SS |
763 | unsigned long __n = (n); \ |
764 | const size_t __recsize = sizeof(*__tmp->rectype); \ | |
765 | struct __kfifo *__kfifo = &__tmp->kfifo; \ | |
2e956fb3 SS |
766 | (__recsize) ? \ |
767 | __kfifo_out_peek_r(__kfifo, __buf, __n, __recsize) : \ | |
768 | __kfifo_out_peek(__kfifo, __buf, __n); \ | |
769 | }) \ | |
770 | ) | |
86d48803 | 771 | |
2e956fb3 SS |
772 | extern int __kfifo_alloc(struct __kfifo *fifo, unsigned int size, |
773 | size_t esize, gfp_t gfp_mask); | |
86d48803 | 774 | |
2e956fb3 | 775 | extern void __kfifo_free(struct __kfifo *fifo); |
86d48803 | 776 | |
2e956fb3 SS |
777 | extern int __kfifo_init(struct __kfifo *fifo, void *buffer, |
778 | unsigned int size, size_t esize); | |
86d48803 | 779 | |
2e956fb3 SS |
780 | extern unsigned int __kfifo_in(struct __kfifo *fifo, |
781 | const void *buf, unsigned int len); | |
86d48803 | 782 | |
2e956fb3 SS |
783 | extern unsigned int __kfifo_out(struct __kfifo *fifo, |
784 | void *buf, unsigned int len); | |
86d48803 | 785 | |
2e956fb3 SS |
786 | extern int __kfifo_from_user(struct __kfifo *fifo, |
787 | const void __user *from, unsigned long len, unsigned int *copied); | |
86d48803 | 788 | |
2e956fb3 SS |
789 | extern int __kfifo_to_user(struct __kfifo *fifo, |
790 | void __user *to, unsigned long len, unsigned int *copied); | |
86d48803 | 791 | |
2e956fb3 SS |
792 | extern unsigned int __kfifo_dma_in_prepare(struct __kfifo *fifo, |
793 | struct scatterlist *sgl, int nents, unsigned int len); | |
86d48803 | 794 | |
2e956fb3 SS |
795 | extern unsigned int __kfifo_dma_out_prepare(struct __kfifo *fifo, |
796 | struct scatterlist *sgl, int nents, unsigned int len); | |
86d48803 | 797 | |
2e956fb3 SS |
798 | extern unsigned int __kfifo_out_peek(struct __kfifo *fifo, |
799 | void *buf, unsigned int len); | |
86d48803 | 800 | |
2e956fb3 SS |
801 | extern unsigned int __kfifo_in_r(struct __kfifo *fifo, |
802 | const void *buf, unsigned int len, size_t recsize); | |
86d48803 | 803 | |
2e956fb3 SS |
804 | extern unsigned int __kfifo_out_r(struct __kfifo *fifo, |
805 | void *buf, unsigned int len, size_t recsize); | |
86d48803 | 806 | |
2e956fb3 SS |
807 | extern int __kfifo_from_user_r(struct __kfifo *fifo, |
808 | const void __user *from, unsigned long len, unsigned int *copied, | |
809 | size_t recsize); | |
86d48803 | 810 | |
2e956fb3 SS |
811 | extern int __kfifo_to_user_r(struct __kfifo *fifo, void __user *to, |
812 | unsigned long len, unsigned int *copied, size_t recsize); | |
86d48803 | 813 | |
2e956fb3 SS |
814 | extern unsigned int __kfifo_dma_in_prepare_r(struct __kfifo *fifo, |
815 | struct scatterlist *sgl, int nents, unsigned int len, size_t recsize); | |
86d48803 | 816 | |
2e956fb3 SS |
817 | extern void __kfifo_dma_in_finish_r(struct __kfifo *fifo, |
818 | unsigned int len, size_t recsize); | |
86d48803 | 819 | |
2e956fb3 SS |
820 | extern unsigned int __kfifo_dma_out_prepare_r(struct __kfifo *fifo, |
821 | struct scatterlist *sgl, int nents, unsigned int len, size_t recsize); | |
86d48803 | 822 | |
2e956fb3 | 823 | extern void __kfifo_dma_out_finish_r(struct __kfifo *fifo, size_t recsize); |
86d48803 | 824 | |
2e956fb3 | 825 | extern unsigned int __kfifo_len_r(struct __kfifo *fifo, size_t recsize); |
86d48803 | 826 | |
b35de43b AR |
827 | extern void __kfifo_skip_r(struct __kfifo *fifo, size_t recsize); |
828 | ||
2e956fb3 SS |
829 | extern unsigned int __kfifo_out_peek_r(struct __kfifo *fifo, |
830 | void *buf, unsigned int len, size_t recsize); | |
86d48803 | 831 | |
2e956fb3 | 832 | extern unsigned int __kfifo_max_r(unsigned int len, size_t recsize); |
86d48803 | 833 | |
1da177e4 | 834 | #endif |