Lines Matching +full:fifo +full:- +full:size
1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * A generic kernel FIFO implementation
8 #include <linux/dma-mapping.h>
18 * internal helper to calculate the unused elements in a fifo
20 static inline unsigned int kfifo_unused(struct __kfifo *fifo)
22 return (fifo->mask + 1) - (fifo->in - fifo->out);
25 int __kfifo_alloc(struct __kfifo *fifo, unsigned int size,
32 size = roundup_pow_of_two(size);
34 fifo->in = 0;
35 fifo->out = 0;
36 fifo->esize = esize;
38 if (size < 2) {
39 fifo->data = NULL;
40 fifo->mask = 0;
41 return -EINVAL;
44 fifo->data = kmalloc_array(esize, size, gfp_mask);
46 if (!fifo->data) {
47 fifo->mask = 0;
48 return -ENOMEM;
50 fifo->mask = size - 1;
56 void __kfifo_free(struct __kfifo *fifo)
58 kfree(fifo->data);
59 fifo->in = 0;
60 fifo->out = 0;
61 fifo->esize = 0;
62 fifo->data = NULL;
63 fifo->mask = 0;
67 int __kfifo_init(struct __kfifo *fifo, void *buffer,
68 unsigned int size, size_t esize)
70 size /= esize;
72 if (!is_power_of_2(size))
73 size = rounddown_pow_of_two(size);
75 fifo->in = 0;
76 fifo->out = 0;
77 fifo->esize = esize;
78 fifo->data = buffer;
80 if (size < 2) {
81 fifo->mask = 0;
82 return -EINVAL;
84 fifo->mask = size - 1;
90 static void kfifo_copy_in(struct __kfifo *fifo, const void *src,
93 unsigned int size = fifo->mask + 1;
94 unsigned int esize = fifo->esize;
97 off &= fifo->mask;
100 size *= esize;
103 l = min(len, size - off);
105 memcpy(fifo->data + off, src, l);
106 memcpy(fifo->data, src + l, len - l);
108 * make sure that the data in the fifo is up to date before
109 * incrementing the fifo->in index counter
114 unsigned int __kfifo_in(struct __kfifo *fifo,
119 l = kfifo_unused(fifo);
123 kfifo_copy_in(fifo, buf, len, fifo->in);
124 fifo->in += len;
129 static void kfifo_copy_out(struct __kfifo *fifo, void *dst,
132 unsigned int size = fifo->mask + 1;
133 unsigned int esize = fifo->esize;
136 off &= fifo->mask;
139 size *= esize;
142 l = min(len, size - off);
144 memcpy(dst, fifo->data + off, l);
145 memcpy(dst + l, fifo->data, len - l);
148 * incrementing the fifo->out index counter
153 unsigned int __kfifo_out_peek(struct __kfifo *fifo,
158 l = fifo->in - fifo->out;
162 kfifo_copy_out(fifo, buf, len, fifo->out);
167 unsigned int __kfifo_out_linear(struct __kfifo *fifo,
170 unsigned int size = fifo->mask + 1;
171 unsigned int off = fifo->out & fifo->mask;
176 return min3(n, fifo->in - fifo->out, size - off);
180 unsigned int __kfifo_out(struct __kfifo *fifo,
183 len = __kfifo_out_peek(fifo, buf, len);
184 fifo->out += len;
189 static unsigned long kfifo_copy_from_user(struct __kfifo *fifo,
193 unsigned int size = fifo->mask + 1;
194 unsigned int esize = fifo->esize;
198 off &= fifo->mask;
201 size *= esize;
204 l = min(len, size - off);
206 ret = copy_from_user(fifo->data + off, from, l);
208 ret = DIV_ROUND_UP(ret + len - l, esize);
210 ret = copy_from_user(fifo->data, from + l, len - l);
215 * make sure that the data in the fifo is up to date before
216 * incrementing the fifo->in index counter
219 *copied = len - ret * esize;
224 int __kfifo_from_user(struct __kfifo *fifo, const void __user *from,
229 unsigned int esize = fifo->esize;
235 l = kfifo_unused(fifo);
239 ret = kfifo_copy_from_user(fifo, from, len, fifo->in, copied);
241 len -= ret;
242 err = -EFAULT;
245 fifo->in += len;
250 static unsigned long kfifo_copy_to_user(struct __kfifo *fifo, void __user *to,
255 unsigned int size = fifo->mask + 1;
256 unsigned int esize = fifo->esize;
258 off &= fifo->mask;
261 size *= esize;
264 l = min(len, size - off);
266 ret = copy_to_user(to, fifo->data + off, l);
268 ret = DIV_ROUND_UP(ret + len - l, esize);
270 ret = copy_to_user(to + l, fifo->data, len - l);
276 * incrementing the fifo->out index counter
279 *copied = len - ret * esize;
284 int __kfifo_to_user(struct __kfifo *fifo, void __user *to,
289 unsigned int esize = fifo->esize;
295 l = fifo->in - fifo->out;
298 ret = kfifo_copy_to_user(fifo, to, len, fifo->out, copied);
300 len -= ret;
301 err = -EFAULT;
304 fifo->out += len;
309 static unsigned int setup_sgl_buf(struct __kfifo *fifo, struct scatterlist *sgl,
313 const void *buf = fifo->data + data_offset;
328 static unsigned int setup_sgl(struct __kfifo *fifo, struct scatterlist *sgl,
331 unsigned int size = fifo->mask + 1;
332 unsigned int esize = fifo->esize;
336 off &= fifo->mask;
339 size *= esize;
342 len_to_end = min(len, size - off);
344 n = setup_sgl_buf(fifo, sgl, off, nents, len_to_end, dma);
345 n += setup_sgl_buf(fifo, sgl + n, 0, nents - n, len - len_to_end, dma);
350 unsigned int __kfifo_dma_in_prepare(struct __kfifo *fifo,
356 l = kfifo_unused(fifo);
360 return setup_sgl(fifo, sgl, nents, len, fifo->in, dma);
364 unsigned int __kfifo_dma_out_prepare(struct __kfifo *fifo,
370 l = fifo->in - fifo->out;
374 return setup_sgl(fifo, sgl, nents, len, fifo->out, dma);
380 unsigned int max = (1 << (recsize << 3)) - 1;
392 * the next record in the fifo
394 static unsigned int __kfifo_peek_n(struct __kfifo *fifo, size_t recsize)
397 unsigned int mask = fifo->mask;
398 unsigned char *data = fifo->data;
400 l = __KFIFO_PEEK(data, fifo->out, mask);
402 if (--recsize)
403 l |= __KFIFO_PEEK(data, fifo->out + 1, mask) << 8;
415 * the record into the fifo
417 static void __kfifo_poke_n(struct __kfifo *fifo, unsigned int n, size_t recsize)
419 unsigned int mask = fifo->mask;
420 unsigned char *data = fifo->data;
422 __KFIFO_POKE(data, fifo->in, mask, n);
425 __KFIFO_POKE(data, fifo->in + 1, mask, n >> 8);
428 unsigned int __kfifo_len_r(struct __kfifo *fifo, size_t recsize)
430 return __kfifo_peek_n(fifo, recsize);
434 unsigned int __kfifo_in_r(struct __kfifo *fifo, const void *buf,
437 if (len + recsize > kfifo_unused(fifo))
440 __kfifo_poke_n(fifo, len, recsize);
442 kfifo_copy_in(fifo, buf, len, fifo->in + recsize);
443 fifo->in += len + recsize;
448 static unsigned int kfifo_out_copy_r(struct __kfifo *fifo,
451 *n = __kfifo_peek_n(fifo, recsize);
456 kfifo_copy_out(fifo, buf, len, fifo->out + recsize);
460 unsigned int __kfifo_out_peek_r(struct __kfifo *fifo, void *buf,
465 if (fifo->in == fifo->out)
468 return kfifo_out_copy_r(fifo, buf, len, recsize, &n);
472 unsigned int __kfifo_out_linear_r(struct __kfifo *fifo,
475 if (fifo->in == fifo->out)
479 *tail = fifo->out + recsize;
481 return min(n, __kfifo_peek_n(fifo, recsize));
485 unsigned int __kfifo_out_r(struct __kfifo *fifo, void *buf,
490 if (fifo->in == fifo->out)
493 len = kfifo_out_copy_r(fifo, buf, len, recsize, &n);
494 fifo->out += n + recsize;
499 void __kfifo_skip_r(struct __kfifo *fifo, size_t recsize)
503 n = __kfifo_peek_n(fifo, recsize);
504 fifo->out += n + recsize;
508 int __kfifo_from_user_r(struct __kfifo *fifo, const void __user *from,
515 if (len + recsize > kfifo_unused(fifo)) {
520 __kfifo_poke_n(fifo, len, recsize);
522 ret = kfifo_copy_from_user(fifo, from, len, fifo->in + recsize, copied);
525 return -EFAULT;
527 fifo->in += len + recsize;
532 int __kfifo_to_user_r(struct __kfifo *fifo, void __user *to,
538 if (fifo->in == fifo->out) {
543 n = __kfifo_peek_n(fifo, recsize);
547 ret = kfifo_copy_to_user(fifo, to, len, fifo->out + recsize, copied);
550 return -EFAULT;
552 fifo->out += n + recsize;
557 unsigned int __kfifo_dma_in_prepare_r(struct __kfifo *fifo,
565 if (len + recsize > kfifo_unused(fifo))
568 return setup_sgl(fifo, sgl, nents, len, fifo->in + recsize, dma);
572 void __kfifo_dma_in_finish_r(struct __kfifo *fifo,
576 __kfifo_poke_n(fifo, len, recsize);
577 fifo->in += len + recsize;
581 unsigned int __kfifo_dma_out_prepare_r(struct __kfifo *fifo,
589 if (len + recsize > fifo->in - fifo->out)
592 return setup_sgl(fifo, sgl, nents, len, fifo->out + recsize, dma);