1 /* SPDX-License-Identifier: BSD-3-Clause
2 * Copyright(c) 2010-2014 Intel Corporation
8 * Initializes the kni fifo structure
11 kni_fifo_init(struct rte_kni_fifo *fifo, unsigned size)
13 /* Ensure size is power of 2 */
14 if (size & (size - 1))
15 rte_panic("KNI fifo size must be power of 2\n");
20 fifo->elem_size = sizeof(void *);
24 * Adds num elements into the fifo. Return the number actually written
26 static inline unsigned
27 kni_fifo_put(struct rte_kni_fifo *fifo, void **data, unsigned num)
30 unsigned fifo_write = fifo->write;
31 unsigned new_write = fifo_write;
33 unsigned fifo_read = fifo->read;
35 for (i = 0; i < num; i++) {
36 new_write = (new_write + 1) & (fifo->len - 1);
38 if (new_write == fifo_read)
40 fifo->buffer[fifo_write] = data[i];
41 fifo_write = new_write;
44 fifo->write = fifo_write;
49 * Get up to num elements from the fifo. Return the number actually read
51 static inline unsigned
52 kni_fifo_get(struct rte_kni_fifo *fifo, void **data, unsigned num)
55 unsigned new_read = fifo->read;
57 unsigned fifo_write = fifo->write;
59 for (i = 0; i < num; i++) {
60 if (new_read == fifo_write)
63 data[i] = fifo->buffer[new_read];
64 new_read = (new_read + 1) & (fifo->len - 1);
67 fifo->read = new_read;
72 * Get the num of elements in the fifo
74 static inline uint32_t
75 kni_fifo_count(struct rte_kni_fifo *fifo)
77 unsigned fifo_write = fifo->write;
79 unsigned fifo_read = fifo->read;
80 return (fifo->len + fifo_write - fifo_read) & (fifo->len - 1);