82 lines
1.5 KiB
C
82 lines
1.5 KiB
C
/*
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* Copyright (C) 2018 Intel Corporation. All rights reserved.
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*
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* SPDX-License-Identifier: BSD-3-Clause
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*/
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#include <asm/errno.h>
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#include <string.h>
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#include <unistd.h>
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#include <stdio.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_write(int fd, shared_buf_t *sbuf)
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{
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const void *start;
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int written;
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if (sbuf == NULL)
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return -EINVAL;
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if (sbuf_is_empty(sbuf)) {
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return 0;
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}
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start = (void *)sbuf + SBUF_HEAD_SIZE + sbuf->head;
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written = write(fd, start, sbuf->ele_size);
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if ( written != sbuf->ele_size) {
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printf("Failed to write. Expect written size %d, returned %d\n",
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sbuf->ele_size, written);
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return -1;
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}
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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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