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-rw-r--r--kernel/kfifo-new.c602
1 files changed, 0 insertions, 602 deletions
diff --git a/kernel/kfifo-new.c b/kernel/kfifo-new.c
deleted file mode 100644
index 02192dd905cc..000000000000
--- a/kernel/kfifo-new.c
+++ /dev/null
@@ -1,602 +0,0 @@
1/*
2 * A generic kernel FIFO implementation
3 *
4 * Copyright (C) 2009/2010 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#include <linux/kernel.h>
23#include <linux/module.h>
24#include <linux/slab.h>
25#include <linux/err.h>
26#include <linux/log2.h>
27#include <linux/uaccess.h>
28#include <linux/kfifo.h>
29
30/*
31 * internal helper to calculate the unused elements in a fifo
32 */
33static inline unsigned int kfifo_unused(struct __kfifo *fifo)
34{
35 return (fifo->mask + 1) - (fifo->in - fifo->out);
36}
37
38int __kfifo_alloc(struct __kfifo *fifo, unsigned int size,
39 size_t esize, gfp_t gfp_mask)
40{
41 /*
42 * round down to the next power of 2, since our 'let the indices
43 * wrap' technique works only in this case.
44 */
45 if (!is_power_of_2(size))
46 size = rounddown_pow_of_two(size);
47
48 fifo->in = 0;
49 fifo->out = 0;
50 fifo->esize = esize;
51
52 if (size < 2) {
53 fifo->data = NULL;
54 fifo->mask = 0;
55 return -EINVAL;
56 }
57
58 fifo->data = kmalloc(size * esize, gfp_mask);
59
60 if (!fifo->data) {
61 fifo->mask = 0;
62 return -ENOMEM;
63 }
64 fifo->mask = size - 1;
65
66 return 0;
67}
68EXPORT_SYMBOL(__kfifo_alloc);
69
70void __kfifo_free(struct __kfifo *fifo)
71{
72 kfree(fifo->data);
73 fifo->in = 0;
74 fifo->out = 0;
75 fifo->esize = 0;
76 fifo->data = NULL;
77 fifo->mask = 0;
78}
79EXPORT_SYMBOL(__kfifo_free);
80
81int __kfifo_init(struct __kfifo *fifo, void *buffer,
82 unsigned int size, size_t esize)
83{
84 size /= esize;
85
86 if (!is_power_of_2(size))
87 size = rounddown_pow_of_two(size);
88
89 fifo->in = 0;
90 fifo->out = 0;
91 fifo->esize = esize;
92 fifo->data = buffer;
93
94 if (size < 2) {
95 fifo->mask = 0;
96 return -EINVAL;
97 }
98 fifo->mask = size - 1;
99
100 return 0;
101}
102EXPORT_SYMBOL(__kfifo_init);
103
104static void kfifo_copy_in(struct __kfifo *fifo, const void *src,
105 unsigned int len, unsigned int off)
106{
107 unsigned int size = fifo->mask + 1;
108 unsigned int esize = fifo->esize;
109 unsigned int l;
110
111 off &= fifo->mask;
112 if (esize != 1) {
113 off *= esize;
114 size *= esize;
115 len *= esize;
116 }
117 l = min(len, size - off);
118
119 memcpy(fifo->data + off, src, l);
120 memcpy(fifo->data, src + l, len - l);
121 /*
122 * make sure that the data in the fifo is up to date before
123 * incrementing the fifo->in index counter
124 */
125 smp_wmb();
126}
127
128unsigned int __kfifo_in(struct __kfifo *fifo,
129 const void *buf, unsigned int len)
130{
131 unsigned int l;
132
133 l = kfifo_unused(fifo);
134 if (len > l)
135 len = l;
136
137 kfifo_copy_in(fifo, buf, len, fifo->in);
138 fifo->in += len;
139 return len;
140}
141EXPORT_SYMBOL(__kfifo_in);
142
143static void kfifo_copy_out(struct __kfifo *fifo, void *dst,
144 unsigned int len, unsigned int off)
145{
146 unsigned int size = fifo->mask + 1;
147 unsigned int esize = fifo->esize;
148 unsigned int l;
149
150 off &= fifo->mask;
151 if (esize != 1) {
152 off *= esize;
153 size *= esize;
154 len *= esize;
155 }
156 l = min(len, size - off);
157
158 memcpy(dst, fifo->data + off, l);
159 memcpy(dst + l, fifo->data, len - l);
160 /*
161 * make sure that the data is copied before
162 * incrementing the fifo->out index counter
163 */
164 smp_wmb();
165}
166
167unsigned int __kfifo_out_peek(struct __kfifo *fifo,
168 void *buf, unsigned int len)
169{
170 unsigned int l;
171
172 l = fifo->in - fifo->out;
173 if (len > l)
174 len = l;
175
176 kfifo_copy_out(fifo, buf, len, fifo->out);
177 return len;
178}
179EXPORT_SYMBOL(__kfifo_out_peek);
180
181unsigned int __kfifo_out(struct __kfifo *fifo,
182 void *buf, unsigned int len)
183{
184 len = __kfifo_out_peek(fifo, buf, len);
185 fifo->out += len;
186 return len;
187}
188EXPORT_SYMBOL(__kfifo_out);
189
190static unsigned long kfifo_copy_from_user(struct __kfifo *fifo,
191 const void __user *from, unsigned int len, unsigned int off,
192 unsigned int *copied)
193{
194 unsigned int size = fifo->mask + 1;
195 unsigned int esize = fifo->esize;
196 unsigned int l;
197 unsigned long ret;
198
199 off &= fifo->mask;
200 if (esize != 1) {
201 off *= esize;
202 size *= esize;
203 len *= esize;
204 }
205 l = min(len, size - off);
206
207 ret = copy_from_user(fifo->data + off, from, l);
208 if (unlikely(ret))
209 ret = DIV_ROUND_UP(ret + len - l, esize);
210 else {
211 ret = copy_from_user(fifo->data, from + l, len - l);
212 if (unlikely(ret))
213 ret = DIV_ROUND_UP(ret, esize);
214 }
215 /*
216 * make sure that the data in the fifo is up to date before
217 * incrementing the fifo->in index counter
218 */
219 smp_wmb();
220 *copied = len - ret;
221 /* return the number of elements which are not copied */
222 return ret;
223}
224
225int __kfifo_from_user(struct __kfifo *fifo, const void __user *from,
226 unsigned long len, unsigned int *copied)
227{
228 unsigned int l;
229 unsigned long ret;
230 unsigned int esize = fifo->esize;
231 int err;
232
233 if (esize != 1)
234 len /= esize;
235
236 l = kfifo_unused(fifo);
237 if (len > l)
238 len = l;
239
240 ret = kfifo_copy_from_user(fifo, from, len, fifo->in, copied);
241 if (unlikely(ret)) {
242 len -= ret;
243 err = -EFAULT;
244 } else
245 err = 0;
246 fifo->in += len;
247 return err;
248}
249EXPORT_SYMBOL(__kfifo_from_user);
250
251static unsigned long kfifo_copy_to_user(struct __kfifo *fifo, void __user *to,
252 unsigned int len, unsigned int off, unsigned int *copied)
253{
254 unsigned int l;
255 unsigned long ret;
256 unsigned int size = fifo->mask + 1;
257 unsigned int esize = fifo->esize;
258
259 off &= fifo->mask;
260 if (esize != 1) {
261 off *= esize;
262 size *= esize;
263 len *= esize;
264 }
265 l = min(len, size - off);
266
267 ret = copy_to_user(to, fifo->data + off, l);
268 if (unlikely(ret))
269 ret = DIV_ROUND_UP(ret + len - l, esize);
270 else {
271 ret = copy_to_user(to + l, fifo->data, len - l);
272 if (unlikely(ret))
273 ret = DIV_ROUND_UP(ret, esize);
274 }
275 /*
276 * make sure that the data is copied before
277 * incrementing the fifo->out index counter
278 */
279 smp_wmb();
280 *copied = len - ret;
281 /* return the number of elements which are not copied */
282 return ret;
283}
284
285int __kfifo_to_user(struct __kfifo *fifo, void __user *to,
286 unsigned long len, unsigned int *copied)
287{
288 unsigned int l;
289 unsigned long ret;
290 unsigned int esize = fifo->esize;
291 int err;
292
293 if (esize != 1)
294 len /= esize;
295
296 l = fifo->in - fifo->out;
297 if (len > l)
298 len = l;
299 ret = kfifo_copy_to_user(fifo, to, len, fifo->out, copied);
300 if (unlikely(ret)) {
301 len -= ret;
302 err = -EFAULT;
303 } else
304 err = 0;
305 fifo->out += len;
306 return err;
307}
308EXPORT_SYMBOL(__kfifo_to_user);
309
310static int setup_sgl_buf(struct scatterlist *sgl, void *buf,
311 int nents, unsigned int len)
312{
313 int n;
314 unsigned int l;
315 unsigned int off;
316 struct page *page;
317
318 if (!nents)
319 return 0;
320
321 if (!len)
322 return 0;
323
324 n = 0;
325 page = virt_to_page(buf);
326 off = offset_in_page(buf);
327 l = 0;
328
329 while (len >= l + PAGE_SIZE - off) {
330 struct page *npage;
331
332 l += PAGE_SIZE;
333 buf += PAGE_SIZE;
334 npage = virt_to_page(buf);
335 if (page_to_phys(page) != page_to_phys(npage) - l) {
336 sgl->page_link = 0;
337 sg_set_page(sgl++, page, l - off, off);
338 if (++n == nents)
339 return n;
340 page = npage;
341 len -= l - off;
342 l = off = 0;
343 }
344 }
345 sgl->page_link = 0;
346 sg_set_page(sgl++, page, len, off);
347 return n + 1;
348}
349
350static unsigned int setup_sgl(struct __kfifo *fifo, struct scatterlist *sgl,
351 int nents, unsigned int len, unsigned int off)
352{
353 unsigned int size = fifo->mask + 1;
354 unsigned int esize = fifo->esize;
355 unsigned int l;
356 unsigned int n;
357
358 off &= fifo->mask;
359 if (esize != 1) {
360 off *= esize;
361 size *= esize;
362 len *= esize;
363 }
364 l = min(len, size - off);
365
366 n = setup_sgl_buf(sgl, fifo->data + off, nents, l);
367 n += setup_sgl_buf(sgl + n, fifo->data, nents - n, len - l);
368
369 if (n)
370 sg_mark_end(sgl + n - 1);
371 return n;
372}
373
374unsigned int __kfifo_dma_in_prepare(struct __kfifo *fifo,
375 struct scatterlist *sgl, int nents, unsigned int len)
376{
377 unsigned int l;
378
379 l = kfifo_unused(fifo);
380 if (len > l)
381 len = l;
382
383 return setup_sgl(fifo, sgl, nents, len, fifo->in);
384}
385EXPORT_SYMBOL(__kfifo_dma_in_prepare);
386
387unsigned int __kfifo_dma_out_prepare(struct __kfifo *fifo,
388 struct scatterlist *sgl, int nents, unsigned int len)
389{
390 unsigned int l;
391
392 l = fifo->in - fifo->out;
393 if (len > l)
394 len = l;
395
396 return setup_sgl(fifo, sgl, nents, len, fifo->out);
397}
398EXPORT_SYMBOL(__kfifo_dma_out_prepare);
399
400unsigned int __kfifo_max_r(unsigned int len, size_t recsize)
401{
402 unsigned int max = (1 << (recsize << 3)) - 1;
403
404 if (len > max)
405 return max;
406 return len;
407}
408
409#define __KFIFO_PEEK(data, out, mask) \
410 ((data)[(out) & (mask)])
411/*
412 * __kfifo_peek_n internal helper function for determinate the length of
413 * the next record in the fifo
414 */
415static unsigned int __kfifo_peek_n(struct __kfifo *fifo, size_t recsize)
416{
417 unsigned int l;
418 unsigned int mask = fifo->mask;
419 unsigned char *data = fifo->data;
420
421 l = __KFIFO_PEEK(data, fifo->out, mask);
422
423 if (--recsize)
424 l |= __KFIFO_PEEK(data, fifo->out + 1, mask) << 8;
425
426 return l;
427}
428
429#define __KFIFO_POKE(data, in, mask, val) \
430 ( \
431 (data)[(in) & (mask)] = (unsigned char)(val) \
432 )
433
434/*
435 * __kfifo_poke_n internal helper function for storeing the length of
436 * the record into the fifo
437 */
438static void __kfifo_poke_n(struct __kfifo *fifo, unsigned int n, size_t recsize)
439{
440 unsigned int mask = fifo->mask;
441 unsigned char *data = fifo->data;
442
443 __KFIFO_POKE(data, fifo->in, mask, n);
444
445 if (recsize > 1)
446 __KFIFO_POKE(data, fifo->in + 1, mask, n >> 8);
447}
448
449unsigned int __kfifo_len_r(struct __kfifo *fifo, size_t recsize)
450{
451 return __kfifo_peek_n(fifo, recsize);
452}
453EXPORT_SYMBOL(__kfifo_len_r);
454
455unsigned int __kfifo_in_r(struct __kfifo *fifo, const void *buf,
456 unsigned int len, size_t recsize)
457{
458 if (len + recsize > kfifo_unused(fifo))
459 return 0;
460
461 __kfifo_poke_n(fifo, len, recsize);
462
463 kfifo_copy_in(fifo, buf, len, fifo->in + recsize);
464 fifo->in += len + recsize;
465 return len;
466}
467EXPORT_SYMBOL(__kfifo_in_r);
468
469static unsigned int kfifo_out_copy_r(struct __kfifo *fifo,
470 void *buf, unsigned int len, size_t recsize, unsigned int *n)
471{
472 *n = __kfifo_peek_n(fifo, recsize);
473
474 if (len > *n)
475 len = *n;
476
477 kfifo_copy_out(fifo, buf, len, fifo->out + recsize);
478 return len;
479}
480
481unsigned int __kfifo_out_peek_r(struct __kfifo *fifo, void *buf,
482 unsigned int len, size_t recsize)
483{
484 unsigned int n;
485
486 if (fifo->in == fifo->out)
487 return 0;
488
489 return kfifo_out_copy_r(fifo, buf, len, recsize, &n);
490}
491EXPORT_SYMBOL(__kfifo_out_peek_r);
492
493unsigned int __kfifo_out_r(struct __kfifo *fifo, void *buf,
494 unsigned int len, size_t recsize)
495{
496 unsigned int n;
497
498 if (fifo->in == fifo->out)
499 return 0;
500
501 len = kfifo_out_copy_r(fifo, buf, len, recsize, &n);
502 fifo->out += n + recsize;
503 return len;
504}
505EXPORT_SYMBOL(__kfifo_out_r);
506
507int __kfifo_from_user_r(struct __kfifo *fifo, const void __user *from,
508 unsigned long len, unsigned int *copied, size_t recsize)
509{
510 unsigned long ret;
511
512 len = __kfifo_max_r(len, recsize);
513
514 if (len + recsize > kfifo_unused(fifo)) {
515 *copied = 0;
516 return 0;
517 }
518
519 __kfifo_poke_n(fifo, len, recsize);
520
521 ret = kfifo_copy_from_user(fifo, from, len, fifo->in + recsize, copied);
522 if (unlikely(ret)) {
523 *copied = 0;
524 return -EFAULT;
525 }
526 fifo->in += len + recsize;
527 return 0;
528}
529EXPORT_SYMBOL(__kfifo_from_user_r);
530
531int __kfifo_to_user_r(struct __kfifo *fifo, void __user *to,
532 unsigned long len, unsigned int *copied, size_t recsize)
533{
534 unsigned long ret;
535 unsigned int n;
536
537 if (fifo->in == fifo->out) {
538 *copied = 0;
539 return 0;
540 }
541
542 n = __kfifo_peek_n(fifo, recsize);
543 if (len > n)
544 len = n;
545
546 ret = kfifo_copy_to_user(fifo, to, len, fifo->out + recsize, copied);
547 if (unlikely(ret)) {
548 *copied = 0;
549 return -EFAULT;
550 }
551 fifo->out += n + recsize;
552 return 0;
553}
554EXPORT_SYMBOL(__kfifo_to_user_r);
555
556unsigned int __kfifo_dma_in_prepare_r(struct __kfifo *fifo,
557 struct scatterlist *sgl, int nents, unsigned int len, size_t recsize)
558{
559 if (!nents)
560 BUG();
561
562 len = __kfifo_max_r(len, recsize);
563
564 if (len + recsize > kfifo_unused(fifo))
565 return 0;
566
567 return setup_sgl(fifo, sgl, nents, len, fifo->in + recsize);
568}
569EXPORT_SYMBOL(__kfifo_dma_in_prepare_r);
570
571void __kfifo_dma_in_finish_r(struct __kfifo *fifo,
572 unsigned int len, size_t recsize)
573{
574 len = __kfifo_max_r(len, recsize);
575 __kfifo_poke_n(fifo, len, recsize);
576 fifo->in += len + recsize;
577}
578EXPORT_SYMBOL(__kfifo_dma_in_finish_r);
579
580unsigned int __kfifo_dma_out_prepare_r(struct __kfifo *fifo,
581 struct scatterlist *sgl, int nents, unsigned int len, size_t recsize)
582{
583 if (!nents)
584 BUG();
585
586 len = __kfifo_max_r(len, recsize);
587
588 if (len + recsize > fifo->in - fifo->out)
589 return 0;
590
591 return setup_sgl(fifo, sgl, nents, len, fifo->out + recsize);
592}
593EXPORT_SYMBOL(__kfifo_dma_out_prepare_r);
594
595void __kfifo_dma_out_finish_r(struct __kfifo *fifo, size_t recsize)
596{
597 unsigned int len;
598
599 len = __kfifo_peek_n(fifo, recsize);
600 fifo->out += len + recsize;
601}
602EXPORT_SYMBOL(__kfifo_dma_out_finish_r);
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