]> git.proxmox.com Git - mirror_ubuntu-jammy-kernel.git/blame - lib/kfifo.c
UBUNTU: SAUCE: arm: fix build error in kvm tracepoint
[mirror_ubuntu-jammy-kernel.git] / lib / kfifo.c
CommitLineData
74ba9207 1// SPDX-License-Identifier: GPL-2.0-or-later
1da177e4 2/*
2e956fb3 3 * A generic kernel FIFO implementation
1da177e4 4 *
2e956fb3 5 * Copyright (C) 2009/2010 Stefani Seibold <stefani@seibold.net>
1da177e4
LT
6 */
7
8#include <linux/kernel.h>
9984de1a 9#include <linux/export.h>
1da177e4
LT
10#include <linux/slab.h>
11#include <linux/err.h>
f84d5a76 12#include <linux/log2.h>
a121f24a 13#include <linux/uaccess.h>
2e956fb3 14#include <linux/kfifo.h>
1da177e4 15
2e956fb3
SS
16/*
17 * internal helper to calculate the unused elements in a fifo
1da177e4 18 */
2e956fb3 19static inline unsigned int kfifo_unused(struct __kfifo *fifo)
1da177e4 20{
2e956fb3 21 return (fifo->mask + 1) - (fifo->in - fifo->out);
1da177e4 22}
1da177e4 23
2e956fb3
SS
24int __kfifo_alloc(struct __kfifo *fifo, unsigned int size,
25 size_t esize, gfp_t gfp_mask)
1da177e4 26{
1da177e4 27 /*
75a24b82 28 * round up to the next power of 2, since our 'let the indices
b33112d1 29 * wrap' technique works only in this case.
1da177e4 30 */
dfe2a77f 31 size = roundup_pow_of_two(size);
2e956fb3
SS
32
33 fifo->in = 0;
34 fifo->out = 0;
35 fifo->esize = esize;
36
37 if (size < 2) {
38 fifo->data = NULL;
39 fifo->mask = 0;
40 return -EINVAL;
1da177e4
LT
41 }
42
6da2ec56 43 fifo->data = kmalloc_array(esize, size, gfp_mask);
2e956fb3
SS
44
45 if (!fifo->data) {
46 fifo->mask = 0;
45465487
SS
47 return -ENOMEM;
48 }
2e956fb3 49 fifo->mask = size - 1;
1da177e4 50
45465487 51 return 0;
1da177e4 52}
2e956fb3 53EXPORT_SYMBOL(__kfifo_alloc);
1da177e4 54
2e956fb3 55void __kfifo_free(struct __kfifo *fifo)
1da177e4 56{
2e956fb3
SS
57 kfree(fifo->data);
58 fifo->in = 0;
59 fifo->out = 0;
60 fifo->esize = 0;
61 fifo->data = NULL;
62 fifo->mask = 0;
1da177e4 63}
2e956fb3 64EXPORT_SYMBOL(__kfifo_free);
1da177e4 65
2e956fb3
SS
66int __kfifo_init(struct __kfifo *fifo, void *buffer,
67 unsigned int size, size_t esize)
a121f24a 68{
2e956fb3
SS
69 size /= esize;
70
ab9bb631
LT
71 if (!is_power_of_2(size))
72 size = rounddown_pow_of_two(size);
2e956fb3
SS
73
74 fifo->in = 0;
75 fifo->out = 0;
76 fifo->esize = esize;
77 fifo->data = buffer;
78
79 if (size < 2) {
80 fifo->mask = 0;
81 return -EINVAL;
a121f24a 82 }
2e956fb3
SS
83 fifo->mask = size - 1;
84
85 return 0;
a121f24a 86}
2e956fb3 87EXPORT_SYMBOL(__kfifo_init);
a121f24a 88
2e956fb3
SS
89static void kfifo_copy_in(struct __kfifo *fifo, const void *src,
90 unsigned int len, unsigned int off)
1da177e4 91{
2e956fb3
SS
92 unsigned int size = fifo->mask + 1;
93 unsigned int esize = fifo->esize;
1da177e4
LT
94 unsigned int l;
95
2e956fb3
SS
96 off &= fifo->mask;
97 if (esize != 1) {
98 off *= esize;
99 size *= esize;
100 len *= esize;
101 }
102 l = min(len, size - off);
103
104 memcpy(fifo->data + off, src, l);
105 memcpy(fifo->data, src + l, len - l);
a45bce49 106 /*
2e956fb3
SS
107 * make sure that the data in the fifo is up to date before
108 * incrementing the fifo->in index counter
a45bce49 109 */
2e956fb3
SS
110 smp_wmb();
111}
a45bce49 112
2e956fb3
SS
113unsigned int __kfifo_in(struct __kfifo *fifo,
114 const void *buf, unsigned int len)
115{
116 unsigned int l;
a121f24a 117
2e956fb3
SS
118 l = kfifo_unused(fifo);
119 if (len > l)
120 len = l;
1da177e4 121
2e956fb3
SS
122 kfifo_copy_in(fifo, buf, len, fifo->in);
123 fifo->in += len;
124 return len;
1da177e4 125}
2e956fb3 126EXPORT_SYMBOL(__kfifo_in);
1da177e4 127
2e956fb3
SS
128static void kfifo_copy_out(struct __kfifo *fifo, void *dst,
129 unsigned int len, unsigned int off)
1da177e4 130{
2e956fb3
SS
131 unsigned int size = fifo->mask + 1;
132 unsigned int esize = fifo->esize;
1da177e4
LT
133 unsigned int l;
134
2e956fb3
SS
135 off &= fifo->mask;
136 if (esize != 1) {
137 off *= esize;
138 size *= esize;
139 len *= esize;
140 }
141 l = min(len, size - off);
142
143 memcpy(dst, fifo->data + off, l);
144 memcpy(dst + l, fifo->data, len - l);
a45bce49 145 /*
2e956fb3
SS
146 * make sure that the data is copied before
147 * incrementing the fifo->out index counter
a45bce49 148 */
2e956fb3
SS
149 smp_wmb();
150}
a45bce49 151
2e956fb3
SS
152unsigned int __kfifo_out_peek(struct __kfifo *fifo,
153 void *buf, unsigned int len)
154{
155 unsigned int l;
a45bce49 156
2e956fb3
SS
157 l = fifo->in - fifo->out;
158 if (len > l)
159 len = l;
a121f24a 160
2e956fb3
SS
161 kfifo_copy_out(fifo, buf, len, fifo->out);
162 return len;
163}
164EXPORT_SYMBOL(__kfifo_out_peek);
1da177e4 165
2e956fb3
SS
166unsigned int __kfifo_out(struct __kfifo *fifo,
167 void *buf, unsigned int len)
168{
169 len = __kfifo_out_peek(fifo, buf, len);
170 fifo->out += len;
171 return len;
a121f24a 172}
2e956fb3 173EXPORT_SYMBOL(__kfifo_out);
a121f24a 174
2e956fb3
SS
175static unsigned long kfifo_copy_from_user(struct __kfifo *fifo,
176 const void __user *from, unsigned int len, unsigned int off,
177 unsigned int *copied)
a121f24a 178{
2e956fb3
SS
179 unsigned int size = fifo->mask + 1;
180 unsigned int esize = fifo->esize;
a121f24a 181 unsigned int l;
2e956fb3 182 unsigned long ret;
a121f24a 183
2e956fb3
SS
184 off &= fifo->mask;
185 if (esize != 1) {
186 off *= esize;
187 size *= esize;
188 len *= esize;
189 }
190 l = min(len, size - off);
191
192 ret = copy_from_user(fifo->data + off, from, l);
193 if (unlikely(ret))
194 ret = DIV_ROUND_UP(ret + len - l, esize);
195 else {
196 ret = copy_from_user(fifo->data, from + l, len - l);
197 if (unlikely(ret))
198 ret = DIV_ROUND_UP(ret, esize);
199 }
a45bce49 200 /*
2e956fb3
SS
201 * make sure that the data in the fifo is up to date before
202 * incrementing the fifo->in index counter
a45bce49 203 */
2e956fb3 204 smp_wmb();
a019e48c 205 *copied = len - ret * esize;
2e956fb3
SS
206 /* return the number of elements which are not copied */
207 return ret;
208}
a45bce49 209
2e956fb3
SS
210int __kfifo_from_user(struct __kfifo *fifo, const void __user *from,
211 unsigned long len, unsigned int *copied)
212{
213 unsigned int l;
214 unsigned long ret;
215 unsigned int esize = fifo->esize;
216 int err;
a45bce49 217
2e956fb3
SS
218 if (esize != 1)
219 len /= esize;
a121f24a 220
2e956fb3
SS
221 l = kfifo_unused(fifo);
222 if (len > l)
223 len = l;
a121f24a 224
2e956fb3
SS
225 ret = kfifo_copy_from_user(fifo, from, len, fifo->in, copied);
226 if (unlikely(ret)) {
227 len -= ret;
228 err = -EFAULT;
229 } else
230 err = 0;
231 fifo->in += len;
232 return err;
86d48803 233}
2e956fb3 234EXPORT_SYMBOL(__kfifo_from_user);
86d48803 235
2e956fb3
SS
236static unsigned long kfifo_copy_to_user(struct __kfifo *fifo, void __user *to,
237 unsigned int len, unsigned int off, unsigned int *copied)
86d48803
SS
238{
239 unsigned int l;
2e956fb3
SS
240 unsigned long ret;
241 unsigned int size = fifo->mask + 1;
242 unsigned int esize = fifo->esize;
243
244 off &= fifo->mask;
245 if (esize != 1) {
246 off *= esize;
247 size *= esize;
248 len *= esize;
249 }
250 l = min(len, size - off);
251
252 ret = copy_to_user(to, fifo->data + off, l);
253 if (unlikely(ret))
254 ret = DIV_ROUND_UP(ret + len - l, esize);
255 else {
256 ret = copy_to_user(to + l, fifo->data, len - l);
257 if (unlikely(ret))
258 ret = DIV_ROUND_UP(ret, esize);
259 }
86d48803 260 /*
2e956fb3
SS
261 * make sure that the data is copied before
262 * incrementing the fifo->out index counter
86d48803 263 */
2e956fb3 264 smp_wmb();
a019e48c 265 *copied = len - ret * esize;
2e956fb3
SS
266 /* return the number of elements which are not copied */
267 return ret;
268}
86d48803 269
2e956fb3
SS
270int __kfifo_to_user(struct __kfifo *fifo, void __user *to,
271 unsigned long len, unsigned int *copied)
272{
273 unsigned int l;
274 unsigned long ret;
275 unsigned int esize = fifo->esize;
276 int err;
86d48803 277
2e956fb3
SS
278 if (esize != 1)
279 len /= esize;
86d48803 280
2e956fb3
SS
281 l = fifo->in - fifo->out;
282 if (len > l)
283 len = l;
284 ret = kfifo_copy_to_user(fifo, to, len, fifo->out, copied);
64ce1037 285 if (unlikely(ret)) {
2e956fb3
SS
286 len -= ret;
287 err = -EFAULT;
288 } else
289 err = 0;
290 fifo->out += len;
291 return err;
292}
293EXPORT_SYMBOL(__kfifo_to_user);
a121f24a 294
2e956fb3
SS
295static int setup_sgl_buf(struct scatterlist *sgl, void *buf,
296 int nents, unsigned int len)
297{
298 int n;
299 unsigned int l;
300 unsigned int off;
301 struct page *page;
302
303 if (!nents)
304 return 0;
305
306 if (!len)
307 return 0;
308
309 n = 0;
310 page = virt_to_page(buf);
311 off = offset_in_page(buf);
312 l = 0;
313
314 while (len >= l + PAGE_SIZE - off) {
315 struct page *npage;
316
317 l += PAGE_SIZE;
318 buf += PAGE_SIZE;
319 npage = virt_to_page(buf);
320 if (page_to_phys(page) != page_to_phys(npage) - l) {
d78a3eda
SS
321 sg_set_page(sgl, page, l - off, off);
322 sgl = sg_next(sgl);
323 if (++n == nents || sgl == NULL)
2e956fb3
SS
324 return n;
325 page = npage;
326 len -= l - off;
327 l = off = 0;
328 }
64ce1037 329 }
d78a3eda 330 sg_set_page(sgl, page, len, off);
2e956fb3 331 return n + 1;
86d48803 332}
1da177e4 333
2e956fb3
SS
334static unsigned int setup_sgl(struct __kfifo *fifo, struct scatterlist *sgl,
335 int nents, unsigned int len, unsigned int off)
86d48803 336{
2e956fb3
SS
337 unsigned int size = fifo->mask + 1;
338 unsigned int esize = fifo->esize;
339 unsigned int l;
340 unsigned int n;
86d48803 341
2e956fb3
SS
342 off &= fifo->mask;
343 if (esize != 1) {
344 off *= esize;
345 size *= esize;
346 len *= esize;
347 }
348 l = min(len, size - off);
349
d78a3eda 350 n = setup_sgl_buf(sgl, fifo->data + off, nents, l);
2e956fb3
SS
351 n += setup_sgl_buf(sgl + n, fifo->data, nents - n, len - l);
352
2e956fb3 353 return n;
86d48803 354}
86d48803 355
2e956fb3
SS
356unsigned int __kfifo_dma_in_prepare(struct __kfifo *fifo,
357 struct scatterlist *sgl, int nents, unsigned int len)
86d48803 358{
2e956fb3 359 unsigned int l;
86d48803 360
2e956fb3
SS
361 l = kfifo_unused(fifo);
362 if (len > l)
363 len = l;
364
365 return setup_sgl(fifo, sgl, nents, len, fifo->in);
1da177e4 366}
2e956fb3 367EXPORT_SYMBOL(__kfifo_dma_in_prepare);
86d48803 368
2e956fb3
SS
369unsigned int __kfifo_dma_out_prepare(struct __kfifo *fifo,
370 struct scatterlist *sgl, int nents, unsigned int len)
86d48803 371{
2e956fb3
SS
372 unsigned int l;
373
374 l = fifo->in - fifo->out;
375 if (len > l)
376 len = l;
377
378 return setup_sgl(fifo, sgl, nents, len, fifo->out);
86d48803 379}
2e956fb3 380EXPORT_SYMBOL(__kfifo_dma_out_prepare);
86d48803 381
2e956fb3 382unsigned int __kfifo_max_r(unsigned int len, size_t recsize)
86d48803 383{
2e956fb3 384 unsigned int max = (1 << (recsize << 3)) - 1;
86d48803 385
2e956fb3
SS
386 if (len > max)
387 return max;
388 return len;
86d48803 389}
30059d93 390EXPORT_SYMBOL(__kfifo_max_r);
a121f24a 391
2e956fb3
SS
392#define __KFIFO_PEEK(data, out, mask) \
393 ((data)[(out) & (mask)])
394/*
395 * __kfifo_peek_n internal helper function for determinate the length of
396 * the next record in the fifo
a121f24a 397 */
2e956fb3 398static unsigned int __kfifo_peek_n(struct __kfifo *fifo, size_t recsize)
a121f24a 399{
2e956fb3
SS
400 unsigned int l;
401 unsigned int mask = fifo->mask;
402 unsigned char *data = fifo->data;
a121f24a 403
2e956fb3 404 l = __KFIFO_PEEK(data, fifo->out, mask);
a121f24a 405
2e956fb3
SS
406 if (--recsize)
407 l |= __KFIFO_PEEK(data, fifo->out + 1, mask) << 8;
408
409 return l;
86d48803 410}
2e956fb3
SS
411
412#define __KFIFO_POKE(data, in, mask, val) \
413 ( \
414 (data)[(in) & (mask)] = (unsigned char)(val) \
415 )
416
417/*
9dbbc3b9 418 * __kfifo_poke_n internal helper function for storing the length of
2e956fb3 419 * the record into the fifo
a5b9e2c1 420 */
2e956fb3 421static void __kfifo_poke_n(struct __kfifo *fifo, unsigned int n, size_t recsize)
a5b9e2c1 422{
2e956fb3
SS
423 unsigned int mask = fifo->mask;
424 unsigned char *data = fifo->data;
a5b9e2c1 425
2e956fb3
SS
426 __KFIFO_POKE(data, fifo->in, mask, n);
427
428 if (recsize > 1)
429 __KFIFO_POKE(data, fifo->in + 1, mask, n >> 8);
a5b9e2c1 430}
a5b9e2c1 431
2e956fb3 432unsigned int __kfifo_len_r(struct __kfifo *fifo, size_t recsize)
86d48803 433{
2e956fb3 434 return __kfifo_peek_n(fifo, recsize);
86d48803 435}
2e956fb3 436EXPORT_SYMBOL(__kfifo_len_r);
a121f24a 437
2e956fb3
SS
438unsigned int __kfifo_in_r(struct __kfifo *fifo, const void *buf,
439 unsigned int len, size_t recsize)
86d48803 440{
2e956fb3
SS
441 if (len + recsize > kfifo_unused(fifo))
442 return 0;
64ce1037 443
2e956fb3 444 __kfifo_poke_n(fifo, len, recsize);
a121f24a 445
2e956fb3
SS
446 kfifo_copy_in(fifo, buf, len, fifo->in + recsize);
447 fifo->in += len + recsize;
448 return len;
86d48803 449}
2e956fb3
SS
450EXPORT_SYMBOL(__kfifo_in_r);
451
452static unsigned int kfifo_out_copy_r(struct __kfifo *fifo,
453 void *buf, unsigned int len, size_t recsize, unsigned int *n)
86d48803 454{
2e956fb3
SS
455 *n = __kfifo_peek_n(fifo, recsize);
456
457 if (len > *n)
458 len = *n;
459
460 kfifo_copy_out(fifo, buf, len, fifo->out + recsize);
461 return len;
462}
463
464unsigned int __kfifo_out_peek_r(struct __kfifo *fifo, void *buf,
465 unsigned int len, size_t recsize)
466{
467 unsigned int n;
468
469 if (fifo->in == fifo->out)
470 return 0;
471
472 return kfifo_out_copy_r(fifo, buf, len, recsize, &n);
86d48803 473}
2e956fb3 474EXPORT_SYMBOL(__kfifo_out_peek_r);
a121f24a 475
2e956fb3
SS
476unsigned int __kfifo_out_r(struct __kfifo *fifo, void *buf,
477 unsigned int len, size_t recsize)
86d48803 478{
2e956fb3
SS
479 unsigned int n;
480
481 if (fifo->in == fifo->out)
482 return 0;
483
484 len = kfifo_out_copy_r(fifo, buf, len, recsize, &n);
485 fifo->out += n + recsize;
486 return len;
86d48803 487}
2e956fb3 488EXPORT_SYMBOL(__kfifo_out_r);
a121f24a 489
b35de43b
AR
490void __kfifo_skip_r(struct __kfifo *fifo, size_t recsize)
491{
492 unsigned int n;
493
494 n = __kfifo_peek_n(fifo, recsize);
495 fifo->out += n + recsize;
496}
497EXPORT_SYMBOL(__kfifo_skip_r);
498
2e956fb3
SS
499int __kfifo_from_user_r(struct __kfifo *fifo, const void __user *from,
500 unsigned long len, unsigned int *copied, size_t recsize)
86d48803 501{
2e956fb3 502 unsigned long ret;
a121f24a 503
2e956fb3 504 len = __kfifo_max_r(len, recsize);
a121f24a 505
2e956fb3
SS
506 if (len + recsize > kfifo_unused(fifo)) {
507 *copied = 0;
508 return 0;
509 }
86d48803 510
2e956fb3 511 __kfifo_poke_n(fifo, len, recsize);
86d48803 512
2e956fb3
SS
513 ret = kfifo_copy_from_user(fifo, from, len, fifo->in + recsize, copied);
514 if (unlikely(ret)) {
515 *copied = 0;
516 return -EFAULT;
517 }
518 fifo->in += len + recsize;
519 return 0;
86d48803 520}
2e956fb3
SS
521EXPORT_SYMBOL(__kfifo_from_user_r);
522
523int __kfifo_to_user_r(struct __kfifo *fifo, void __user *to,
524 unsigned long len, unsigned int *copied, size_t recsize)
86d48803 525{
2e956fb3
SS
526 unsigned long ret;
527 unsigned int n;
528
529 if (fifo->in == fifo->out) {
530 *copied = 0;
531 return 0;
532 }
533
534 n = __kfifo_peek_n(fifo, recsize);
535 if (len > n)
536 len = n;
537
538 ret = kfifo_copy_to_user(fifo, to, len, fifo->out + recsize, copied);
539 if (unlikely(ret)) {
540 *copied = 0;
541 return -EFAULT;
542 }
543 fifo->out += n + recsize;
544 return 0;
a121f24a 545}
2e956fb3 546EXPORT_SYMBOL(__kfifo_to_user_r);
a121f24a 547
2e956fb3
SS
548unsigned int __kfifo_dma_in_prepare_r(struct __kfifo *fifo,
549 struct scatterlist *sgl, int nents, unsigned int len, size_t recsize)
86d48803 550{
89b3ac63 551 BUG_ON(!nents);
2e956fb3
SS
552
553 len = __kfifo_max_r(len, recsize);
554
555 if (len + recsize > kfifo_unused(fifo))
556 return 0;
557
558 return setup_sgl(fifo, sgl, nents, len, fifo->in + recsize);
86d48803 559}
2e956fb3 560EXPORT_SYMBOL(__kfifo_dma_in_prepare_r);
86d48803 561
2e956fb3
SS
562void __kfifo_dma_in_finish_r(struct __kfifo *fifo,
563 unsigned int len, size_t recsize)
86d48803 564{
2e956fb3
SS
565 len = __kfifo_max_r(len, recsize);
566 __kfifo_poke_n(fifo, len, recsize);
567 fifo->in += len + recsize;
86d48803 568}
2e956fb3 569EXPORT_SYMBOL(__kfifo_dma_in_finish_r);
86d48803 570
2e956fb3
SS
571unsigned int __kfifo_dma_out_prepare_r(struct __kfifo *fifo,
572 struct scatterlist *sgl, int nents, unsigned int len, size_t recsize)
86d48803 573{
89b3ac63 574 BUG_ON(!nents);
2e956fb3
SS
575
576 len = __kfifo_max_r(len, recsize);
577
578 if (len + recsize > fifo->in - fifo->out)
579 return 0;
580
581 return setup_sgl(fifo, sgl, nents, len, fifo->out + recsize);
86d48803 582}
2e956fb3
SS
583EXPORT_SYMBOL(__kfifo_dma_out_prepare_r);
584
585void __kfifo_dma_out_finish_r(struct __kfifo *fifo, size_t recsize)
586{
587 unsigned int len;
86d48803 588
2e956fb3
SS
589 len = __kfifo_peek_n(fifo, recsize);
590 fifo->out += len + recsize;
591}
592EXPORT_SYMBOL(__kfifo_dma_out_finish_r);