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1da177e4 | 1 | /* |
2e956fb3 | 2 | * A generic kernel FIFO implementation |
1da177e4 | 3 | * |
2e956fb3 | 4 | * Copyright (C) 2009/2010 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 | |
d78a3eda | 13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
1da177e4 LT |
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 | #include <linux/kernel.h> | |
9984de1a | 23 | #include <linux/export.h> |
1da177e4 LT |
24 | #include <linux/slab.h> |
25 | #include <linux/err.h> | |
f84d5a76 | 26 | #include <linux/log2.h> |
a121f24a | 27 | #include <linux/uaccess.h> |
2e956fb3 | 28 | #include <linux/kfifo.h> |
1da177e4 | 29 | |
2e956fb3 SS |
30 | /* |
31 | * internal helper to calculate the unused elements in a fifo | |
1da177e4 | 32 | */ |
2e956fb3 | 33 | static inline unsigned int kfifo_unused(struct __kfifo *fifo) |
1da177e4 | 34 | { |
2e956fb3 | 35 | return (fifo->mask + 1) - (fifo->in - fifo->out); |
1da177e4 | 36 | } |
1da177e4 | 37 | |
2e956fb3 SS |
38 | int __kfifo_alloc(struct __kfifo *fifo, unsigned int size, |
39 | size_t esize, gfp_t gfp_mask) | |
1da177e4 | 40 | { |
1da177e4 | 41 | /* |
2e956fb3 | 42 | * round down to the next power of 2, since our 'let the indices |
b33112d1 | 43 | * wrap' technique works only in this case. |
1da177e4 | 44 | */ |
dfe2a77f | 45 | size = roundup_pow_of_two(size); |
2e956fb3 SS |
46 | |
47 | fifo->in = 0; | |
48 | fifo->out = 0; | |
49 | fifo->esize = esize; | |
50 | ||
51 | if (size < 2) { | |
52 | fifo->data = NULL; | |
53 | fifo->mask = 0; | |
54 | return -EINVAL; | |
1da177e4 LT |
55 | } |
56 | ||
2e956fb3 SS |
57 | fifo->data = kmalloc(size * esize, gfp_mask); |
58 | ||
59 | if (!fifo->data) { | |
60 | fifo->mask = 0; | |
45465487 SS |
61 | return -ENOMEM; |
62 | } | |
2e956fb3 | 63 | fifo->mask = size - 1; |
1da177e4 | 64 | |
45465487 | 65 | return 0; |
1da177e4 | 66 | } |
2e956fb3 | 67 | EXPORT_SYMBOL(__kfifo_alloc); |
1da177e4 | 68 | |
2e956fb3 | 69 | void __kfifo_free(struct __kfifo *fifo) |
1da177e4 | 70 | { |
2e956fb3 SS |
71 | kfree(fifo->data); |
72 | fifo->in = 0; | |
73 | fifo->out = 0; | |
74 | fifo->esize = 0; | |
75 | fifo->data = NULL; | |
76 | fifo->mask = 0; | |
1da177e4 | 77 | } |
2e956fb3 | 78 | EXPORT_SYMBOL(__kfifo_free); |
1da177e4 | 79 | |
2e956fb3 SS |
80 | int __kfifo_init(struct __kfifo *fifo, void *buffer, |
81 | unsigned int size, size_t esize) | |
a121f24a | 82 | { |
2e956fb3 SS |
83 | size /= esize; |
84 | ||
d60b6c50 LT |
85 | if (!is_power_of_2(size)) |
86 | size = rounddown_pow_of_two(size); | |
2e956fb3 SS |
87 | |
88 | fifo->in = 0; | |
89 | fifo->out = 0; | |
90 | fifo->esize = esize; | |
91 | fifo->data = buffer; | |
92 | ||
93 | if (size < 2) { | |
94 | fifo->mask = 0; | |
95 | return -EINVAL; | |
a121f24a | 96 | } |
2e956fb3 SS |
97 | fifo->mask = size - 1; |
98 | ||
99 | return 0; | |
a121f24a | 100 | } |
2e956fb3 | 101 | EXPORT_SYMBOL(__kfifo_init); |
a121f24a | 102 | |
2e956fb3 SS |
103 | static void kfifo_copy_in(struct __kfifo *fifo, const void *src, |
104 | unsigned int len, unsigned int off) | |
1da177e4 | 105 | { |
2e956fb3 SS |
106 | unsigned int size = fifo->mask + 1; |
107 | unsigned int esize = fifo->esize; | |
1da177e4 LT |
108 | unsigned int l; |
109 | ||
2e956fb3 SS |
110 | off &= fifo->mask; |
111 | if (esize != 1) { | |
112 | off *= esize; | |
113 | size *= esize; | |
114 | len *= esize; | |
115 | } | |
116 | l = min(len, size - off); | |
117 | ||
118 | memcpy(fifo->data + off, src, l); | |
119 | memcpy(fifo->data, src + l, len - l); | |
a45bce49 | 120 | /* |
2e956fb3 SS |
121 | * make sure that the data in the fifo is up to date before |
122 | * incrementing the fifo->in index counter | |
a45bce49 | 123 | */ |
2e956fb3 SS |
124 | smp_wmb(); |
125 | } | |
a45bce49 | 126 | |
2e956fb3 SS |
127 | unsigned int __kfifo_in(struct __kfifo *fifo, |
128 | const void *buf, unsigned int len) | |
129 | { | |
130 | unsigned int l; | |
a121f24a | 131 | |
2e956fb3 SS |
132 | l = kfifo_unused(fifo); |
133 | if (len > l) | |
134 | len = l; | |
1da177e4 | 135 | |
2e956fb3 SS |
136 | kfifo_copy_in(fifo, buf, len, fifo->in); |
137 | fifo->in += len; | |
138 | return len; | |
1da177e4 | 139 | } |
2e956fb3 | 140 | EXPORT_SYMBOL(__kfifo_in); |
1da177e4 | 141 | |
2e956fb3 SS |
142 | static void kfifo_copy_out(struct __kfifo *fifo, void *dst, |
143 | unsigned int len, unsigned int off) | |
1da177e4 | 144 | { |
2e956fb3 SS |
145 | unsigned int size = fifo->mask + 1; |
146 | unsigned int esize = fifo->esize; | |
1da177e4 LT |
147 | unsigned int l; |
148 | ||
2e956fb3 SS |
149 | off &= fifo->mask; |
150 | if (esize != 1) { | |
151 | off *= esize; | |
152 | size *= esize; | |
153 | len *= esize; | |
154 | } | |
155 | l = min(len, size - off); | |
156 | ||
157 | memcpy(dst, fifo->data + off, l); | |
158 | memcpy(dst + l, fifo->data, len - l); | |
a45bce49 | 159 | /* |
2e956fb3 SS |
160 | * make sure that the data is copied before |
161 | * incrementing the fifo->out index counter | |
a45bce49 | 162 | */ |
2e956fb3 SS |
163 | smp_wmb(); |
164 | } | |
a45bce49 | 165 | |
2e956fb3 SS |
166 | unsigned int __kfifo_out_peek(struct __kfifo *fifo, |
167 | void *buf, unsigned int len) | |
168 | { | |
169 | unsigned int l; | |
a45bce49 | 170 | |
2e956fb3 SS |
171 | l = fifo->in - fifo->out; |
172 | if (len > l) | |
173 | len = l; | |
a121f24a | 174 | |
2e956fb3 SS |
175 | kfifo_copy_out(fifo, buf, len, fifo->out); |
176 | return len; | |
177 | } | |
178 | EXPORT_SYMBOL(__kfifo_out_peek); | |
1da177e4 | 179 | |
2e956fb3 SS |
180 | unsigned int __kfifo_out(struct __kfifo *fifo, |
181 | void *buf, unsigned int len) | |
182 | { | |
183 | len = __kfifo_out_peek(fifo, buf, len); | |
184 | fifo->out += len; | |
185 | return len; | |
a121f24a | 186 | } |
2e956fb3 | 187 | EXPORT_SYMBOL(__kfifo_out); |
a121f24a | 188 | |
2e956fb3 SS |
189 | static unsigned long kfifo_copy_from_user(struct __kfifo *fifo, |
190 | const void __user *from, unsigned int len, unsigned int off, | |
191 | unsigned int *copied) | |
a121f24a | 192 | { |
2e956fb3 SS |
193 | unsigned int size = fifo->mask + 1; |
194 | unsigned int esize = fifo->esize; | |
a121f24a | 195 | unsigned int l; |
2e956fb3 | 196 | unsigned long ret; |
a121f24a | 197 | |
2e956fb3 SS |
198 | off &= fifo->mask; |
199 | if (esize != 1) { | |
200 | off *= esize; | |
201 | size *= esize; | |
202 | len *= esize; | |
203 | } | |
204 | l = min(len, size - off); | |
205 | ||
206 | ret = copy_from_user(fifo->data + off, from, l); | |
207 | if (unlikely(ret)) | |
208 | ret = DIV_ROUND_UP(ret + len - l, esize); | |
209 | else { | |
210 | ret = copy_from_user(fifo->data, from + l, len - l); | |
211 | if (unlikely(ret)) | |
212 | ret = DIV_ROUND_UP(ret, esize); | |
213 | } | |
a45bce49 | 214 | /* |
2e956fb3 SS |
215 | * make sure that the data in the fifo is up to date before |
216 | * incrementing the fifo->in index counter | |
a45bce49 | 217 | */ |
2e956fb3 | 218 | smp_wmb(); |
a019e48c | 219 | *copied = len - ret * esize; |
2e956fb3 SS |
220 | /* return the number of elements which are not copied */ |
221 | return ret; | |
222 | } | |
a45bce49 | 223 | |
2e956fb3 SS |
224 | int __kfifo_from_user(struct __kfifo *fifo, const void __user *from, |
225 | unsigned long len, unsigned int *copied) | |
226 | { | |
227 | unsigned int l; | |
228 | unsigned long ret; | |
229 | unsigned int esize = fifo->esize; | |
230 | int err; | |
a45bce49 | 231 | |
2e956fb3 SS |
232 | if (esize != 1) |
233 | len /= esize; | |
a121f24a | 234 | |
2e956fb3 SS |
235 | l = kfifo_unused(fifo); |
236 | if (len > l) | |
237 | len = l; | |
a121f24a | 238 | |
2e956fb3 SS |
239 | ret = kfifo_copy_from_user(fifo, from, len, fifo->in, copied); |
240 | if (unlikely(ret)) { | |
241 | len -= ret; | |
242 | err = -EFAULT; | |
243 | } else | |
244 | err = 0; | |
245 | fifo->in += len; | |
246 | return err; | |
86d48803 | 247 | } |
2e956fb3 | 248 | EXPORT_SYMBOL(__kfifo_from_user); |
86d48803 | 249 | |
2e956fb3 SS |
250 | static unsigned long kfifo_copy_to_user(struct __kfifo *fifo, void __user *to, |
251 | unsigned int len, unsigned int off, unsigned int *copied) | |
86d48803 SS |
252 | { |
253 | unsigned int l; | |
2e956fb3 SS |
254 | unsigned long ret; |
255 | unsigned int size = fifo->mask + 1; | |
256 | unsigned int esize = fifo->esize; | |
257 | ||
258 | off &= fifo->mask; | |
259 | if (esize != 1) { | |
260 | off *= esize; | |
261 | size *= esize; | |
262 | len *= esize; | |
263 | } | |
264 | l = min(len, size - off); | |
265 | ||
266 | ret = copy_to_user(to, fifo->data + off, l); | |
267 | if (unlikely(ret)) | |
268 | ret = DIV_ROUND_UP(ret + len - l, esize); | |
269 | else { | |
270 | ret = copy_to_user(to + l, fifo->data, len - l); | |
271 | if (unlikely(ret)) | |
272 | ret = DIV_ROUND_UP(ret, esize); | |
273 | } | |
86d48803 | 274 | /* |
2e956fb3 SS |
275 | * make sure that the data is copied before |
276 | * incrementing the fifo->out index counter | |
86d48803 | 277 | */ |
2e956fb3 | 278 | smp_wmb(); |
a019e48c | 279 | *copied = len - ret * esize; |
2e956fb3 SS |
280 | /* return the number of elements which are not copied */ |
281 | return ret; | |
282 | } | |
86d48803 | 283 | |
2e956fb3 SS |
284 | int __kfifo_to_user(struct __kfifo *fifo, void __user *to, |
285 | unsigned long len, unsigned int *copied) | |
286 | { | |
287 | unsigned int l; | |
288 | unsigned long ret; | |
289 | unsigned int esize = fifo->esize; | |
290 | int err; | |
86d48803 | 291 | |
2e956fb3 SS |
292 | if (esize != 1) |
293 | len /= esize; | |
86d48803 | 294 | |
2e956fb3 SS |
295 | l = fifo->in - fifo->out; |
296 | if (len > l) | |
297 | len = l; | |
298 | ret = kfifo_copy_to_user(fifo, to, len, fifo->out, copied); | |
64ce1037 | 299 | if (unlikely(ret)) { |
2e956fb3 SS |
300 | len -= ret; |
301 | err = -EFAULT; | |
302 | } else | |
303 | err = 0; | |
304 | fifo->out += len; | |
305 | return err; | |
306 | } | |
307 | EXPORT_SYMBOL(__kfifo_to_user); | |
a121f24a | 308 | |
2e956fb3 SS |
309 | static int setup_sgl_buf(struct scatterlist *sgl, void *buf, |
310 | int nents, unsigned int len) | |
311 | { | |
312 | int n; | |
313 | unsigned int l; | |
314 | unsigned int off; | |
315 | struct page *page; | |
316 | ||
317 | if (!nents) | |
318 | return 0; | |
319 | ||
320 | if (!len) | |
321 | return 0; | |
322 | ||
323 | n = 0; | |
324 | page = virt_to_page(buf); | |
325 | off = offset_in_page(buf); | |
326 | l = 0; | |
327 | ||
328 | while (len >= l + PAGE_SIZE - off) { | |
329 | struct page *npage; | |
330 | ||
331 | l += PAGE_SIZE; | |
332 | buf += PAGE_SIZE; | |
333 | npage = virt_to_page(buf); | |
334 | if (page_to_phys(page) != page_to_phys(npage) - l) { | |
d78a3eda SS |
335 | sg_set_page(sgl, page, l - off, off); |
336 | sgl = sg_next(sgl); | |
337 | if (++n == nents || sgl == NULL) | |
2e956fb3 SS |
338 | return n; |
339 | page = npage; | |
340 | len -= l - off; | |
341 | l = off = 0; | |
342 | } | |
64ce1037 | 343 | } |
d78a3eda | 344 | sg_set_page(sgl, page, len, off); |
2e956fb3 | 345 | return n + 1; |
86d48803 | 346 | } |
1da177e4 | 347 | |
2e956fb3 SS |
348 | static unsigned int setup_sgl(struct __kfifo *fifo, struct scatterlist *sgl, |
349 | int nents, unsigned int len, unsigned int off) | |
86d48803 | 350 | { |
2e956fb3 SS |
351 | unsigned int size = fifo->mask + 1; |
352 | unsigned int esize = fifo->esize; | |
353 | unsigned int l; | |
354 | unsigned int n; | |
86d48803 | 355 | |
2e956fb3 SS |
356 | off &= fifo->mask; |
357 | if (esize != 1) { | |
358 | off *= esize; | |
359 | size *= esize; | |
360 | len *= esize; | |
361 | } | |
362 | l = min(len, size - off); | |
363 | ||
d78a3eda | 364 | n = setup_sgl_buf(sgl, fifo->data + off, nents, l); |
2e956fb3 SS |
365 | n += setup_sgl_buf(sgl + n, fifo->data, nents - n, len - l); |
366 | ||
2e956fb3 | 367 | return n; |
86d48803 | 368 | } |
86d48803 | 369 | |
2e956fb3 SS |
370 | unsigned int __kfifo_dma_in_prepare(struct __kfifo *fifo, |
371 | struct scatterlist *sgl, int nents, unsigned int len) | |
86d48803 | 372 | { |
2e956fb3 | 373 | unsigned int l; |
86d48803 | 374 | |
2e956fb3 SS |
375 | l = kfifo_unused(fifo); |
376 | if (len > l) | |
377 | len = l; | |
378 | ||
379 | return setup_sgl(fifo, sgl, nents, len, fifo->in); | |
1da177e4 | 380 | } |
2e956fb3 | 381 | EXPORT_SYMBOL(__kfifo_dma_in_prepare); |
86d48803 | 382 | |
2e956fb3 SS |
383 | unsigned int __kfifo_dma_out_prepare(struct __kfifo *fifo, |
384 | struct scatterlist *sgl, int nents, unsigned int len) | |
86d48803 | 385 | { |
2e956fb3 SS |
386 | unsigned int l; |
387 | ||
388 | l = fifo->in - fifo->out; | |
389 | if (len > l) | |
390 | len = l; | |
391 | ||
392 | return setup_sgl(fifo, sgl, nents, len, fifo->out); | |
86d48803 | 393 | } |
2e956fb3 | 394 | EXPORT_SYMBOL(__kfifo_dma_out_prepare); |
86d48803 | 395 | |
2e956fb3 | 396 | unsigned int __kfifo_max_r(unsigned int len, size_t recsize) |
86d48803 | 397 | { |
2e956fb3 | 398 | unsigned int max = (1 << (recsize << 3)) - 1; |
86d48803 | 399 | |
2e956fb3 SS |
400 | if (len > max) |
401 | return max; | |
402 | return len; | |
86d48803 | 403 | } |
30059d93 | 404 | EXPORT_SYMBOL(__kfifo_max_r); |
a121f24a | 405 | |
2e956fb3 SS |
406 | #define __KFIFO_PEEK(data, out, mask) \ |
407 | ((data)[(out) & (mask)]) | |
408 | /* | |
409 | * __kfifo_peek_n internal helper function for determinate the length of | |
410 | * the next record in the fifo | |
a121f24a | 411 | */ |
2e956fb3 | 412 | static unsigned int __kfifo_peek_n(struct __kfifo *fifo, size_t recsize) |
a121f24a | 413 | { |
2e956fb3 SS |
414 | unsigned int l; |
415 | unsigned int mask = fifo->mask; | |
416 | unsigned char *data = fifo->data; | |
a121f24a | 417 | |
2e956fb3 | 418 | l = __KFIFO_PEEK(data, fifo->out, mask); |
a121f24a | 419 | |
2e956fb3 SS |
420 | if (--recsize) |
421 | l |= __KFIFO_PEEK(data, fifo->out + 1, mask) << 8; | |
422 | ||
423 | return l; | |
86d48803 | 424 | } |
2e956fb3 SS |
425 | |
426 | #define __KFIFO_POKE(data, in, mask, val) \ | |
427 | ( \ | |
428 | (data)[(in) & (mask)] = (unsigned char)(val) \ | |
429 | ) | |
430 | ||
431 | /* | |
432 | * __kfifo_poke_n internal helper function for storeing the length of | |
433 | * the record into the fifo | |
a5b9e2c1 | 434 | */ |
2e956fb3 | 435 | static void __kfifo_poke_n(struct __kfifo *fifo, unsigned int n, size_t recsize) |
a5b9e2c1 | 436 | { |
2e956fb3 SS |
437 | unsigned int mask = fifo->mask; |
438 | unsigned char *data = fifo->data; | |
a5b9e2c1 | 439 | |
2e956fb3 SS |
440 | __KFIFO_POKE(data, fifo->in, mask, n); |
441 | ||
442 | if (recsize > 1) | |
443 | __KFIFO_POKE(data, fifo->in + 1, mask, n >> 8); | |
a5b9e2c1 | 444 | } |
a5b9e2c1 | 445 | |
2e956fb3 | 446 | unsigned int __kfifo_len_r(struct __kfifo *fifo, size_t recsize) |
86d48803 | 447 | { |
2e956fb3 | 448 | return __kfifo_peek_n(fifo, recsize); |
86d48803 | 449 | } |
2e956fb3 | 450 | EXPORT_SYMBOL(__kfifo_len_r); |
a121f24a | 451 | |
2e956fb3 SS |
452 | unsigned int __kfifo_in_r(struct __kfifo *fifo, const void *buf, |
453 | unsigned int len, size_t recsize) | |
86d48803 | 454 | { |
2e956fb3 SS |
455 | if (len + recsize > kfifo_unused(fifo)) |
456 | return 0; | |
64ce1037 | 457 | |
2e956fb3 | 458 | __kfifo_poke_n(fifo, len, recsize); |
a121f24a | 459 | |
2e956fb3 SS |
460 | kfifo_copy_in(fifo, buf, len, fifo->in + recsize); |
461 | fifo->in += len + recsize; | |
462 | return len; | |
86d48803 | 463 | } |
2e956fb3 SS |
464 | EXPORT_SYMBOL(__kfifo_in_r); |
465 | ||
466 | static unsigned int kfifo_out_copy_r(struct __kfifo *fifo, | |
467 | void *buf, unsigned int len, size_t recsize, unsigned int *n) | |
86d48803 | 468 | { |
2e956fb3 SS |
469 | *n = __kfifo_peek_n(fifo, recsize); |
470 | ||
471 | if (len > *n) | |
472 | len = *n; | |
473 | ||
474 | kfifo_copy_out(fifo, buf, len, fifo->out + recsize); | |
475 | return len; | |
476 | } | |
477 | ||
478 | unsigned int __kfifo_out_peek_r(struct __kfifo *fifo, void *buf, | |
479 | unsigned int len, size_t recsize) | |
480 | { | |
481 | unsigned int n; | |
482 | ||
483 | if (fifo->in == fifo->out) | |
484 | return 0; | |
485 | ||
486 | return kfifo_out_copy_r(fifo, buf, len, recsize, &n); | |
86d48803 | 487 | } |
2e956fb3 | 488 | EXPORT_SYMBOL(__kfifo_out_peek_r); |
a121f24a | 489 | |
2e956fb3 SS |
490 | unsigned int __kfifo_out_r(struct __kfifo *fifo, void *buf, |
491 | unsigned int len, size_t recsize) | |
86d48803 | 492 | { |
2e956fb3 SS |
493 | unsigned int n; |
494 | ||
495 | if (fifo->in == fifo->out) | |
496 | return 0; | |
497 | ||
498 | len = kfifo_out_copy_r(fifo, buf, len, recsize, &n); | |
499 | fifo->out += n + recsize; | |
500 | return len; | |
86d48803 | 501 | } |
2e956fb3 | 502 | EXPORT_SYMBOL(__kfifo_out_r); |
a121f24a | 503 | |
b35de43b AR |
504 | void __kfifo_skip_r(struct __kfifo *fifo, size_t recsize) |
505 | { | |
506 | unsigned int n; | |
507 | ||
508 | n = __kfifo_peek_n(fifo, recsize); | |
509 | fifo->out += n + recsize; | |
510 | } | |
511 | EXPORT_SYMBOL(__kfifo_skip_r); | |
512 | ||
2e956fb3 SS |
513 | int __kfifo_from_user_r(struct __kfifo *fifo, const void __user *from, |
514 | unsigned long len, unsigned int *copied, size_t recsize) | |
86d48803 | 515 | { |
2e956fb3 | 516 | unsigned long ret; |
a121f24a | 517 | |
2e956fb3 | 518 | len = __kfifo_max_r(len, recsize); |
a121f24a | 519 | |
2e956fb3 SS |
520 | if (len + recsize > kfifo_unused(fifo)) { |
521 | *copied = 0; | |
522 | return 0; | |
523 | } | |
86d48803 | 524 | |
2e956fb3 | 525 | __kfifo_poke_n(fifo, len, recsize); |
86d48803 | 526 | |
2e956fb3 SS |
527 | ret = kfifo_copy_from_user(fifo, from, len, fifo->in + recsize, copied); |
528 | if (unlikely(ret)) { | |
529 | *copied = 0; | |
530 | return -EFAULT; | |
531 | } | |
532 | fifo->in += len + recsize; | |
533 | return 0; | |
86d48803 | 534 | } |
2e956fb3 SS |
535 | EXPORT_SYMBOL(__kfifo_from_user_r); |
536 | ||
537 | int __kfifo_to_user_r(struct __kfifo *fifo, void __user *to, | |
538 | unsigned long len, unsigned int *copied, size_t recsize) | |
86d48803 | 539 | { |
2e956fb3 SS |
540 | unsigned long ret; |
541 | unsigned int n; | |
542 | ||
543 | if (fifo->in == fifo->out) { | |
544 | *copied = 0; | |
545 | return 0; | |
546 | } | |
547 | ||
548 | n = __kfifo_peek_n(fifo, recsize); | |
549 | if (len > n) | |
550 | len = n; | |
551 | ||
552 | ret = kfifo_copy_to_user(fifo, to, len, fifo->out + recsize, copied); | |
553 | if (unlikely(ret)) { | |
554 | *copied = 0; | |
555 | return -EFAULT; | |
556 | } | |
557 | fifo->out += n + recsize; | |
558 | return 0; | |
a121f24a | 559 | } |
2e956fb3 | 560 | EXPORT_SYMBOL(__kfifo_to_user_r); |
a121f24a | 561 | |
2e956fb3 SS |
562 | unsigned int __kfifo_dma_in_prepare_r(struct __kfifo *fifo, |
563 | struct scatterlist *sgl, int nents, unsigned int len, size_t recsize) | |
86d48803 | 564 | { |
89b3ac63 | 565 | BUG_ON(!nents); |
2e956fb3 SS |
566 | |
567 | len = __kfifo_max_r(len, recsize); | |
568 | ||
569 | if (len + recsize > kfifo_unused(fifo)) | |
570 | return 0; | |
571 | ||
572 | return setup_sgl(fifo, sgl, nents, len, fifo->in + recsize); | |
86d48803 | 573 | } |
2e956fb3 | 574 | EXPORT_SYMBOL(__kfifo_dma_in_prepare_r); |
86d48803 | 575 | |
2e956fb3 SS |
576 | void __kfifo_dma_in_finish_r(struct __kfifo *fifo, |
577 | unsigned int len, size_t recsize) | |
86d48803 | 578 | { |
2e956fb3 SS |
579 | len = __kfifo_max_r(len, recsize); |
580 | __kfifo_poke_n(fifo, len, recsize); | |
581 | fifo->in += len + recsize; | |
86d48803 | 582 | } |
2e956fb3 | 583 | EXPORT_SYMBOL(__kfifo_dma_in_finish_r); |
86d48803 | 584 | |
2e956fb3 SS |
585 | unsigned int __kfifo_dma_out_prepare_r(struct __kfifo *fifo, |
586 | struct scatterlist *sgl, int nents, unsigned int len, size_t recsize) | |
86d48803 | 587 | { |
89b3ac63 | 588 | BUG_ON(!nents); |
2e956fb3 SS |
589 | |
590 | len = __kfifo_max_r(len, recsize); | |
591 | ||
592 | if (len + recsize > fifo->in - fifo->out) | |
593 | return 0; | |
594 | ||
595 | return setup_sgl(fifo, sgl, nents, len, fifo->out + recsize); | |
86d48803 | 596 | } |
2e956fb3 SS |
597 | EXPORT_SYMBOL(__kfifo_dma_out_prepare_r); |
598 | ||
599 | void __kfifo_dma_out_finish_r(struct __kfifo *fifo, size_t recsize) | |
600 | { | |
601 | unsigned int len; | |
86d48803 | 602 | |
2e956fb3 SS |
603 | len = __kfifo_peek_n(fifo, recsize); |
604 | fifo->out += len + recsize; | |
605 | } | |
606 | EXPORT_SYMBOL(__kfifo_dma_out_finish_r); |