79 lines
2.4 KiB
C
79 lines
2.4 KiB
C
/*
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* Copyright (C) 2018 Intel Corporation. All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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*
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* * Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* * Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in
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* the documentation and/or other materials provided with the
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* distribution.
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* * Neither the name of Intel Corporation nor the names of its
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* contributors may be used to endorse or promote products derived
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* from this software without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
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* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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#include <asm/errno.h>
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#include <string.h>
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#include <stdbool.h>
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#include "sbuf.h"
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static inline bool sbuf_is_empty(shared_buf_t *sbuf)
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{
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return (sbuf->head == sbuf->tail);
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}
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static inline uint32_t sbuf_next_ptr(uint32_t pos,
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uint32_t span, uint32_t scope)
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{
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pos += span;
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pos = (pos >= scope) ? (pos - scope) : pos;
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return pos;
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}
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int sbuf_get(shared_buf_t *sbuf, uint8_t *data)
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{
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const void *from;
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if ((sbuf == NULL) || (data == NULL))
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return -EINVAL;
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if (sbuf_is_empty(sbuf)) {
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/* no data available */
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return 0;
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}
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from = (void *)sbuf + SBUF_HEAD_SIZE + sbuf->head;
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memcpy(data, from, sbuf->ele_size);
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sbuf->head = sbuf_next_ptr(sbuf->head, sbuf->ele_size, sbuf->size);
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return sbuf->ele_size;
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}
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int sbuf_clear_buffered(shared_buf_t *sbuf)
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{
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if (sbuf == NULL)
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return -EINVAL;
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sbuf->head = sbuf->tail;
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return 0;
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}
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