3  * A generic kernel FIFO implementation
17  * internal helper to calculate the unused elements in a fifo
19 static inline unsigned int kfifo_unused(struct __kfifo *fifo)  in kfifo_unused()  argument
21 	return (fifo->mask + 1) - (fifo->in - fifo->out);  in kfifo_unused()
24 int __kfifo_alloc(struct __kfifo *fifo, unsigned int size,  in __kfifo_alloc()  argument
33 	fifo->in = 0;  in __kfifo_alloc()
34 	fifo->out = 0;  in __kfifo_alloc()
35 	fifo->esize = esize;  in __kfifo_alloc()
38 		fifo->data = NULL;  in __kfifo_alloc()
39 		fifo->mask = 0;  in __kfifo_alloc()
43 	fifo->data = kmalloc_array(esize, size, gfp_mask);  in __kfifo_alloc()
45 	if (!fifo->data) {  in __kfifo_alloc()
46 		fifo->mask = 0;  in __kfifo_alloc()
49 	fifo->mask = size - 1;  in __kfifo_alloc()
55 void __kfifo_free(struct __kfifo *fifo)  in __kfifo_free()  argument
57 	kfree(fifo->data);  in __kfifo_free()
58 	fifo->in = 0;  in __kfifo_free()
59 	fifo->out = 0;  in __kfifo_free()
60 	fifo->esize = 0;  in __kfifo_free()
61 	fifo->data = NULL;  in __kfifo_free()
62 	fifo->mask = 0;  in __kfifo_free()
66 int __kfifo_init(struct __kfifo *fifo, void *buffer,  in __kfifo_init()  argument
74 	fifo->in = 0;  in __kfifo_init()
75 	fifo->out = 0;  in __kfifo_init()
76 	fifo->esize = esize;  in __kfifo_init()
77 	fifo->data = buffer;  in __kfifo_init()
80 		fifo->mask = 0;  in __kfifo_init()
83 	fifo->mask = size - 1;  in __kfifo_init()
89 static void kfifo_copy_in(struct __kfifo *fifo, const void *src,  in kfifo_copy_in()  argument
92 	unsigned int size = fifo->mask + 1;  in kfifo_copy_in()
93 	unsigned int esize = fifo->esize;  in kfifo_copy_in()
96 	off &= fifo->mask;  in kfifo_copy_in()
104 	memcpy(fifo->data + off, src, l);  in kfifo_copy_in()
105 	memcpy(fifo->data, src + l, len - l);  in kfifo_copy_in()
107 	 * make sure that the data in the fifo is up to date before  in kfifo_copy_in()
108 	 * incrementing the fifo->in index counter  in kfifo_copy_in()
113 unsigned int __kfifo_in(struct __kfifo *fifo,  in __kfifo_in()  argument
118 	l = kfifo_unused(fifo);  in __kfifo_in()
122 	kfifo_copy_in(fifo, buf, len, fifo->in);  in __kfifo_in()
123 	fifo->in += len;  in __kfifo_in()
128 static void kfifo_copy_out(struct __kfifo *fifo, void *dst,  in kfifo_copy_out()  argument
131 	unsigned int size = fifo->mask + 1;  in kfifo_copy_out()
132 	unsigned int esize = fifo->esize;  in kfifo_copy_out()
135 	off &= fifo->mask;  in kfifo_copy_out()
143 	memcpy(dst, fifo->data + off, l);  in kfifo_copy_out()
144 	memcpy(dst + l, fifo->data, len - l);  in kfifo_copy_out()
147 	 * incrementing the fifo->out index counter  in kfifo_copy_out()
152 unsigned int __kfifo_out_peek(struct __kfifo *fifo,  in __kfifo_out_peek()  argument
157 	l = fifo->in - fifo->out;  in __kfifo_out_peek()
161 	kfifo_copy_out(fifo, buf, len, fifo->out);  in __kfifo_out_peek()
166 unsigned int __kfifo_out(struct __kfifo *fifo,  in __kfifo_out()  argument
169 	len = __kfifo_out_peek(fifo, buf, len);  in __kfifo_out()
170 	fifo->out += len;  in __kfifo_out()
175 static unsigned long kfifo_copy_from_user(struct __kfifo *fifo,  in kfifo_copy_from_user()  argument
179 	unsigned int size = fifo->mask + 1;  in kfifo_copy_from_user()
180 	unsigned int esize = fifo->esize;  in kfifo_copy_from_user()
184 	off &= fifo->mask;  in kfifo_copy_from_user()
192 	ret = copy_from_user(fifo->data + off, from, l);  in kfifo_copy_from_user()
196 		ret = copy_from_user(fifo->data, from + l, len - l);  in kfifo_copy_from_user()
201 	 * make sure that the data in the fifo is up to date before  in kfifo_copy_from_user()
202 	 * incrementing the fifo->in index counter  in kfifo_copy_from_user()
210 int __kfifo_from_user(struct __kfifo *fifo, const void __user *from,  in __kfifo_from_user()  argument
215 	unsigned int esize = fifo->esize;  in __kfifo_from_user()
221 	l = kfifo_unused(fifo);  in __kfifo_from_user()
225 	ret = kfifo_copy_from_user(fifo, from, len, fifo->in, copied);  in __kfifo_from_user()
231 	fifo->in += len;  in __kfifo_from_user()
236 static unsigned long kfifo_copy_to_user(struct __kfifo *fifo, void __user *to,  in kfifo_copy_to_user()  argument
241 	unsigned int size = fifo->mask + 1;  in kfifo_copy_to_user()
242 	unsigned int esize = fifo->esize;  in kfifo_copy_to_user()
244 	off &= fifo->mask;  in kfifo_copy_to_user()
252 	ret = copy_to_user(to, fifo->data + off, l);  in kfifo_copy_to_user()
256 		ret = copy_to_user(to + l, fifo->data, len - l);  in kfifo_copy_to_user()
262 	 * incrementing the fifo->out index counter  in kfifo_copy_to_user()
270 int __kfifo_to_user(struct __kfifo *fifo, void __user *to,  in __kfifo_to_user()  argument
275 	unsigned int esize = fifo->esize;  in __kfifo_to_user()
281 	l = fifo->in - fifo->out;  in __kfifo_to_user()
284 	ret = kfifo_copy_to_user(fifo, to, len, fifo->out, copied);  in __kfifo_to_user()
290 	fifo->out += len;  in __kfifo_to_user()
334 static unsigned int setup_sgl(struct __kfifo *fifo, struct scatterlist *sgl,  in setup_sgl()  argument
337 	unsigned int size = fifo->mask + 1;  in setup_sgl()
338 	unsigned int esize = fifo->esize;  in setup_sgl()
342 	off &= fifo->mask;  in setup_sgl()
350 	n = setup_sgl_buf(sgl, fifo->data + off, nents, l);  in setup_sgl()
351 	n += setup_sgl_buf(sgl + n, fifo->data, nents - n, len - l);  in setup_sgl()
356 unsigned int __kfifo_dma_in_prepare(struct __kfifo *fifo,  in __kfifo_dma_in_prepare()  argument
361 	l = kfifo_unused(fifo);  in __kfifo_dma_in_prepare()
365 	return setup_sgl(fifo, sgl, nents, len, fifo->in);  in __kfifo_dma_in_prepare()
369 unsigned int __kfifo_dma_out_prepare(struct __kfifo *fifo,  in __kfifo_dma_out_prepare()  argument
374 	l = fifo->in - fifo->out;  in __kfifo_dma_out_prepare()
378 	return setup_sgl(fifo, sgl, nents, len, fifo->out);  in __kfifo_dma_out_prepare()
396  * the next record in the fifo
398 static unsigned int __kfifo_peek_n(struct __kfifo *fifo, size_t recsize)  in __kfifo_peek_n()  argument
401 	unsigned int mask = fifo->mask;  in __kfifo_peek_n()
402 	unsigned char *data = fifo->data;  in __kfifo_peek_n()
404 	l = __KFIFO_PEEK(data, fifo->out, mask);  in __kfifo_peek_n()
407 		l |= __KFIFO_PEEK(data, fifo->out + 1, mask) << 8;  in __kfifo_peek_n()
419  * the record into the fifo
421 static void __kfifo_poke_n(struct __kfifo *fifo, unsigned int n, size_t recsize)  in __kfifo_poke_n()  argument
423 	unsigned int mask = fifo->mask;  in __kfifo_poke_n()
424 	unsigned char *data = fifo->data;  in __kfifo_poke_n()
426 	__KFIFO_POKE(data, fifo->in, mask, n);  in __kfifo_poke_n()
429 		__KFIFO_POKE(data, fifo->in + 1, mask, n >> 8);  in __kfifo_poke_n()
432 unsigned int __kfifo_len_r(struct __kfifo *fifo, size_t recsize)  in __kfifo_len_r()  argument
434 	return __kfifo_peek_n(fifo, recsize);  in __kfifo_len_r()
438 unsigned int __kfifo_in_r(struct __kfifo *fifo, const void *buf,  in __kfifo_in_r()  argument
441 	if (len + recsize > kfifo_unused(fifo))  in __kfifo_in_r()
444 	__kfifo_poke_n(fifo, len, recsize);  in __kfifo_in_r()
446 	kfifo_copy_in(fifo, buf, len, fifo->in + recsize);  in __kfifo_in_r()
447 	fifo->in += len + recsize;  in __kfifo_in_r()
452 static unsigned int kfifo_out_copy_r(struct __kfifo *fifo,  in kfifo_out_copy_r()  argument
455 	*n = __kfifo_peek_n(fifo, recsize);  in kfifo_out_copy_r()
460 	kfifo_copy_out(fifo, buf, len, fifo->out + recsize);  in kfifo_out_copy_r()
464 unsigned int __kfifo_out_peek_r(struct __kfifo *fifo, void *buf,  in __kfifo_out_peek_r()  argument
469 	if (fifo->in == fifo->out)  in __kfifo_out_peek_r()
472 	return kfifo_out_copy_r(fifo, buf, len, recsize, &n);  in __kfifo_out_peek_r()
476 unsigned int __kfifo_out_r(struct __kfifo *fifo, void *buf,  in __kfifo_out_r()  argument
481 	if (fifo->in == fifo->out)  in __kfifo_out_r()
484 	len = kfifo_out_copy_r(fifo, buf, len, recsize, &n);  in __kfifo_out_r()
485 	fifo->out += n + recsize;  in __kfifo_out_r()
490 void __kfifo_skip_r(struct __kfifo *fifo, size_t recsize)  in __kfifo_skip_r()  argument
494 	n = __kfifo_peek_n(fifo, recsize);  in __kfifo_skip_r()
495 	fifo->out += n + recsize;  in __kfifo_skip_r()
499 int __kfifo_from_user_r(struct __kfifo *fifo, const void __user *from,  in __kfifo_from_user_r()  argument
506 	if (len + recsize > kfifo_unused(fifo)) {  in __kfifo_from_user_r()
511 	__kfifo_poke_n(fifo, len, recsize);  in __kfifo_from_user_r()
513 	ret = kfifo_copy_from_user(fifo, from, len, fifo->in + recsize, copied);  in __kfifo_from_user_r()
518 	fifo->in += len + recsize;  in __kfifo_from_user_r()
523 int __kfifo_to_user_r(struct __kfifo *fifo, void __user *to,  in __kfifo_to_user_r()  argument
529 	if (fifo->in == fifo->out) {  in __kfifo_to_user_r()
534 	n = __kfifo_peek_n(fifo, recsize);  in __kfifo_to_user_r()
538 	ret = kfifo_copy_to_user(fifo, to, len, fifo->out + recsize, copied);  in __kfifo_to_user_r()
543 	fifo->out += n + recsize;  in __kfifo_to_user_r()
548 unsigned int __kfifo_dma_in_prepare_r(struct __kfifo *fifo,  in __kfifo_dma_in_prepare_r()  argument
555 	if (len + recsize > kfifo_unused(fifo))  in __kfifo_dma_in_prepare_r()
558 	return setup_sgl(fifo, sgl, nents, len, fifo->in + recsize);  in __kfifo_dma_in_prepare_r()
562 void __kfifo_dma_in_finish_r(struct __kfifo *fifo,  in __kfifo_dma_in_finish_r()  argument
566 	__kfifo_poke_n(fifo, len, recsize);  in __kfifo_dma_in_finish_r()
567 	fifo->in += len + recsize;  in __kfifo_dma_in_finish_r()
571 unsigned int __kfifo_dma_out_prepare_r(struct __kfifo *fifo,  in __kfifo_dma_out_prepare_r()  argument
578 	if (len + recsize > fifo->in - fifo->out)  in __kfifo_dma_out_prepare_r()
581 	return setup_sgl(fifo, sgl, nents, len, fifo->out + recsize);  in __kfifo_dma_out_prepare_r()
585 void __kfifo_dma_out_finish_r(struct __kfifo *fifo, size_t recsize)  in __kfifo_dma_out_finish_r()  argument
589 	len = __kfifo_peek_n(fifo, recsize);  in __kfifo_dma_out_finish_r()
590 	fifo->out += len + recsize;  in __kfifo_dma_out_finish_r()