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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;
+}