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/*-
* BSD LICENSE
*
* Copyright(c) 2010-2014 Intel Corporation. All rights reserved.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* * Neither the name of Intel Corporation nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/**
* Initializes the kni fifo structure
*/
static void
kni_fifo_init(struct rte_kni_fifo *fifo, unsigned size)
{
/* Ensure size is power of 2 */
if (size & (size - 1))
rte_panic("KNI fifo size must be power of 2\n");
fifo->write = 0;
fifo->read = 0;
fifo->len = size;
fifo->elem_size = sizeof(void *);
}
/**
* Adds num elements into the fifo. Return the number actually written
*/
static inline unsigned
kni_fifo_put(struct rte_kni_fifo *fifo, void **data, unsigned num)
{
unsigned i = 0;
unsigned fifo_write = fifo->write;
unsigned fifo_read = fifo->read;
unsigned new_write = fifo_write;
for (i = 0; i < num; i++) {
new_write = (new_write + 1) & (fifo->len - 1);
if (new_write == fifo_read)
break;
fifo->buffer[fifo_write] = data[i];
fifo_write = new_write;
}
fifo->write = fifo_write;
return i;
}
/**
* Get up to num elements from the fifo. Return the number actully read
*/
static inline unsigned
kni_fifo_get(struct rte_kni_fifo *fifo, void **data, unsigned num)
{
unsigned i = 0;
unsigned new_read = fifo->read;
unsigned fifo_write = fifo->write;
for (i = 0; i < num; i++) {
if (new_read == fifo_write)
break;
data[i] = fifo->buffer[new_read];
new_read = (new_read + 1) & (fifo->len - 1);
}
fifo->read = new_read;
return i;
}
/**
* Get the num of elements in the fifo
*/
static inline uint32_t
kni_fifo_count(struct rte_kni_fifo *fifo)
{
return (fifo->len + fifo->write - fifo->read) & (fifo->len - 1);
}
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