2  * A generic kernel FIFO implementation
31  * internal helper to calculate the unused elements in a fifo
33 static inline unsigned int kfifo_unused(struct __kfifo *fifo)  in kfifo_unused()  argument
35 	return (fifo->mask + 1) - (fifo->in - fifo->out);  in kfifo_unused()
38 int __kfifo_alloc(struct __kfifo *fifo, unsigned int size,  in __kfifo_alloc()  argument
47 	fifo->in = 0;  in __kfifo_alloc()
48 	fifo->out = 0;  in __kfifo_alloc()
49 	fifo->esize = esize;  in __kfifo_alloc()
52 		fifo->data = NULL;  in __kfifo_alloc()
53 		fifo->mask = 0;  in __kfifo_alloc()
57 	fifo->data = kmalloc_array(esize, size, gfp_mask);  in __kfifo_alloc()
59 	if (!fifo->data) {  in __kfifo_alloc()
60 		fifo->mask = 0;  in __kfifo_alloc()
63 	fifo->mask = size - 1;  in __kfifo_alloc()
69 void __kfifo_free(struct __kfifo *fifo)  in __kfifo_free()  argument
71 	kfree(fifo->data);  in __kfifo_free()
72 	fifo->in = 0;  in __kfifo_free()
73 	fifo->out = 0;  in __kfifo_free()
74 	fifo->esize = 0;  in __kfifo_free()
75 	fifo->data = NULL;  in __kfifo_free()
76 	fifo->mask = 0;  in __kfifo_free()
80 int __kfifo_init(struct __kfifo *fifo, void *buffer,  in __kfifo_init()  argument
88 	fifo->in = 0;  in __kfifo_init()
89 	fifo->out = 0;  in __kfifo_init()
90 	fifo->esize = esize;  in __kfifo_init()
91 	fifo->data = buffer;  in __kfifo_init()
94 		fifo->mask = 0;  in __kfifo_init()
97 	fifo->mask = size - 1;  in __kfifo_init()
103 static void kfifo_copy_in(struct __kfifo *fifo, const void *src,  in kfifo_copy_in()  argument
106 	unsigned int size = fifo->mask + 1;  in kfifo_copy_in()
107 	unsigned int esize = fifo->esize;  in kfifo_copy_in()
110 	off &= fifo->mask;  in kfifo_copy_in()
118 	memcpy(fifo->data + off, src, l);  in kfifo_copy_in()
119 	memcpy(fifo->data, src + l, len - l);  in kfifo_copy_in()
121 	 * make sure that the data in the fifo is up to date before  in kfifo_copy_in()
122 	 * incrementing the fifo->in index counter  in kfifo_copy_in()
127 unsigned int __kfifo_in(struct __kfifo *fifo,  in __kfifo_in()  argument
132 	l = kfifo_unused(fifo);  in __kfifo_in()
136 	kfifo_copy_in(fifo, buf, len, fifo->in);  in __kfifo_in()
137 	fifo->in += len;  in __kfifo_in()
142 static void kfifo_copy_out(struct __kfifo *fifo, void *dst,  in kfifo_copy_out()  argument
145 	unsigned int size = fifo->mask + 1;  in kfifo_copy_out()
146 	unsigned int esize = fifo->esize;  in kfifo_copy_out()
149 	off &= fifo->mask;  in kfifo_copy_out()
157 	memcpy(dst, fifo->data + off, l);  in kfifo_copy_out()
158 	memcpy(dst + l, fifo->data, len - l);  in kfifo_copy_out()
161 	 * incrementing the fifo->out index counter  in kfifo_copy_out()
166 unsigned int __kfifo_out_peek(struct __kfifo *fifo,  in __kfifo_out_peek()  argument
171 	l = fifo->in - fifo->out;  in __kfifo_out_peek()
175 	kfifo_copy_out(fifo, buf, len, fifo->out);  in __kfifo_out_peek()
180 unsigned int __kfifo_out(struct __kfifo *fifo,  in __kfifo_out()  argument
183 	len = __kfifo_out_peek(fifo, buf, len);  in __kfifo_out()
184 	fifo->out += len;  in __kfifo_out()
189 static unsigned long kfifo_copy_from_user(struct __kfifo *fifo,  in kfifo_copy_from_user()  argument
193 	unsigned int size = fifo->mask + 1;  in kfifo_copy_from_user()
194 	unsigned int esize = fifo->esize;  in kfifo_copy_from_user()
198 	off &= fifo->mask;  in kfifo_copy_from_user()
206 	ret = copy_from_user(fifo->data + off, from, l);  in kfifo_copy_from_user()
210 		ret = copy_from_user(fifo->data, from + l, len - l);  in kfifo_copy_from_user()
215 	 * make sure that the data in the fifo is up to date before  in kfifo_copy_from_user()
216 	 * incrementing the fifo->in index counter  in kfifo_copy_from_user()
224 int __kfifo_from_user(struct __kfifo *fifo, const void __user *from,  in __kfifo_from_user()  argument
229 	unsigned int esize = fifo->esize;  in __kfifo_from_user()
235 	l = kfifo_unused(fifo);  in __kfifo_from_user()
239 	ret = kfifo_copy_from_user(fifo, from, len, fifo->in, copied);  in __kfifo_from_user()
245 	fifo->in += len;  in __kfifo_from_user()
250 static unsigned long kfifo_copy_to_user(struct __kfifo *fifo, void __user *to,  in kfifo_copy_to_user()  argument
255 	unsigned int size = fifo->mask + 1;  in kfifo_copy_to_user()
256 	unsigned int esize = fifo->esize;  in kfifo_copy_to_user()
258 	off &= fifo->mask;  in kfifo_copy_to_user()
266 	ret = copy_to_user(to, fifo->data + off, l);  in kfifo_copy_to_user()
270 		ret = copy_to_user(to + l, fifo->data, len - l);  in kfifo_copy_to_user()
276 	 * incrementing the fifo->out index counter  in kfifo_copy_to_user()
284 int __kfifo_to_user(struct __kfifo *fifo, void __user *to,  in __kfifo_to_user()  argument
289 	unsigned int esize = fifo->esize;  in __kfifo_to_user()
295 	l = fifo->in - fifo->out;  in __kfifo_to_user()
298 	ret = kfifo_copy_to_user(fifo, to, len, fifo->out, copied);  in __kfifo_to_user()
304 	fifo->out += len;  in __kfifo_to_user()
348 static unsigned int setup_sgl(struct __kfifo *fifo, struct scatterlist *sgl,  in setup_sgl()  argument
351 	unsigned int size = fifo->mask + 1;  in setup_sgl()
352 	unsigned int esize = fifo->esize;  in setup_sgl()
356 	off &= fifo->mask;  in setup_sgl()
364 	n = setup_sgl_buf(sgl, fifo->data + off, nents, l);  in setup_sgl()
365 	n += setup_sgl_buf(sgl + n, fifo->data, nents - n, len - l);  in setup_sgl()
370 unsigned int __kfifo_dma_in_prepare(struct __kfifo *fifo,  in __kfifo_dma_in_prepare()  argument
375 	l = kfifo_unused(fifo);  in __kfifo_dma_in_prepare()
379 	return setup_sgl(fifo, sgl, nents, len, fifo->in);  in __kfifo_dma_in_prepare()
383 unsigned int __kfifo_dma_out_prepare(struct __kfifo *fifo,  in __kfifo_dma_out_prepare()  argument
388 	l = fifo->in - fifo->out;  in __kfifo_dma_out_prepare()
392 	return setup_sgl(fifo, sgl, nents, len, fifo->out);  in __kfifo_dma_out_prepare()
410  * the next record in the fifo
412 static unsigned int __kfifo_peek_n(struct __kfifo *fifo, size_t recsize)  in __kfifo_peek_n()  argument
415 	unsigned int mask = fifo->mask;  in __kfifo_peek_n()
416 	unsigned char *data = fifo->data;  in __kfifo_peek_n()
418 	l = __KFIFO_PEEK(data, fifo->out, mask);  in __kfifo_peek_n()
421 		l |= __KFIFO_PEEK(data, fifo->out + 1, mask) << 8;  in __kfifo_peek_n()
433  * the record into the fifo
435 static void __kfifo_poke_n(struct __kfifo *fifo, unsigned int n, size_t recsize)  in __kfifo_poke_n()  argument
437 	unsigned int mask = fifo->mask;  in __kfifo_poke_n()
438 	unsigned char *data = fifo->data;  in __kfifo_poke_n()
440 	__KFIFO_POKE(data, fifo->in, mask, n);  in __kfifo_poke_n()
443 		__KFIFO_POKE(data, fifo->in + 1, mask, n >> 8);  in __kfifo_poke_n()
446 unsigned int __kfifo_len_r(struct __kfifo *fifo, size_t recsize)  in __kfifo_len_r()  argument
448 	return __kfifo_peek_n(fifo, recsize);  in __kfifo_len_r()
452 unsigned int __kfifo_in_r(struct __kfifo *fifo, const void *buf,  in __kfifo_in_r()  argument
455 	if (len + recsize > kfifo_unused(fifo))  in __kfifo_in_r()
458 	__kfifo_poke_n(fifo, len, recsize);  in __kfifo_in_r()
460 	kfifo_copy_in(fifo, buf, len, fifo->in + recsize);  in __kfifo_in_r()
461 	fifo->in += len + recsize;  in __kfifo_in_r()
466 static unsigned int kfifo_out_copy_r(struct __kfifo *fifo,  in kfifo_out_copy_r()  argument
469 	*n = __kfifo_peek_n(fifo, recsize);  in kfifo_out_copy_r()
474 	kfifo_copy_out(fifo, buf, len, fifo->out + recsize);  in kfifo_out_copy_r()
478 unsigned int __kfifo_out_peek_r(struct __kfifo *fifo, void *buf,  in __kfifo_out_peek_r()  argument
483 	if (fifo->in == fifo->out)  in __kfifo_out_peek_r()
486 	return kfifo_out_copy_r(fifo, buf, len, recsize, &n);  in __kfifo_out_peek_r()
490 unsigned int __kfifo_out_r(struct __kfifo *fifo, void *buf,  in __kfifo_out_r()  argument
495 	if (fifo->in == fifo->out)  in __kfifo_out_r()
498 	len = kfifo_out_copy_r(fifo, buf, len, recsize, &n);  in __kfifo_out_r()
499 	fifo->out += n + recsize;  in __kfifo_out_r()
504 void __kfifo_skip_r(struct __kfifo *fifo, size_t recsize)  in __kfifo_skip_r()  argument
508 	n = __kfifo_peek_n(fifo, recsize);  in __kfifo_skip_r()
509 	fifo->out += n + recsize;  in __kfifo_skip_r()
513 int __kfifo_from_user_r(struct __kfifo *fifo, const void __user *from,  in __kfifo_from_user_r()  argument
520 	if (len + recsize > kfifo_unused(fifo)) {  in __kfifo_from_user_r()
525 	__kfifo_poke_n(fifo, len, recsize);  in __kfifo_from_user_r()
527 	ret = kfifo_copy_from_user(fifo, from, len, fifo->in + recsize, copied);  in __kfifo_from_user_r()
532 	fifo->in += len + recsize;  in __kfifo_from_user_r()
537 int __kfifo_to_user_r(struct __kfifo *fifo, void __user *to,  in __kfifo_to_user_r()  argument
543 	if (fifo->in == fifo->out) {  in __kfifo_to_user_r()
548 	n = __kfifo_peek_n(fifo, recsize);  in __kfifo_to_user_r()
552 	ret = kfifo_copy_to_user(fifo, to, len, fifo->out + recsize, copied);  in __kfifo_to_user_r()
557 	fifo->out += n + recsize;  in __kfifo_to_user_r()
562 unsigned int __kfifo_dma_in_prepare_r(struct __kfifo *fifo,  in __kfifo_dma_in_prepare_r()  argument
569 	if (len + recsize > kfifo_unused(fifo))  in __kfifo_dma_in_prepare_r()
572 	return setup_sgl(fifo, sgl, nents, len, fifo->in + recsize);  in __kfifo_dma_in_prepare_r()
576 void __kfifo_dma_in_finish_r(struct __kfifo *fifo,  in __kfifo_dma_in_finish_r()  argument
580 	__kfifo_poke_n(fifo, len, recsize);  in __kfifo_dma_in_finish_r()
581 	fifo->in += len + recsize;  in __kfifo_dma_in_finish_r()
585 unsigned int __kfifo_dma_out_prepare_r(struct __kfifo *fifo,  in __kfifo_dma_out_prepare_r()  argument
592 	if (len + recsize > fifo->in - fifo->out)  in __kfifo_dma_out_prepare_r()
595 	return setup_sgl(fifo, sgl, nents, len, fifo->out + recsize);  in __kfifo_dma_out_prepare_r()
599 void __kfifo_dma_out_finish_r(struct __kfifo *fifo, size_t recsize)  in __kfifo_dma_out_finish_r()  argument
603 	len = __kfifo_peek_n(fifo, recsize);  in __kfifo_dma_out_finish_r()
604 	fifo->out += len + recsize;  in __kfifo_dma_out_finish_r()