forked from Mirrors/opensbi
9dc95021db
This patch does following improvements to sbi_fifo: 1. Use valid SBI_Exxxx error codes instead of -1 2. The sbi_fifo_is_full() and sbi_fifo_is_empty() did not acquire qlock before accessing head and tail hence fixed it 3. Added avail member for ease in debugging and simplifying head/tail updates. Due to above changes size of sbi_fifo changes from 48 bytes to 56 bytes. Signed-off-by: Anup Patel <anup.patel@wdc.com>
109 lines
2.1 KiB
C
109 lines
2.1 KiB
C
/*
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* SPDX-License-Identifier: BSD-2-Clause
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*
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* Copyright (c) 2019 Western Digital Corporation or its affiliates.
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*
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* Authors:
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* Atish Patra<atish.patra@wdc.com>
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*
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*/
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#include <sbi/riscv_locks.h>
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#include <sbi/sbi_error.h>
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#include <sbi/sbi_fifo.h>
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#include <plat/string.h>
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void sbi_fifo_init(struct sbi_fifo *fifo, void *queue_mem,
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unsigned long entries, unsigned long entry_size)
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{
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fifo->queue = queue_mem;
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fifo->num_entries = entries;
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fifo->entry_size = entry_size;
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SPIN_LOCK_INIT(&fifo->qlock);
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fifo->avail = fifo->head = fifo->tail = 0;
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memset(fifo->queue, 0, entries * entry_size);
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}
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/* Note: must be called with fifo->qlock held */
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static inline bool __sbi_fifo_is_full(struct sbi_fifo *fifo)
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{
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return (fifo->avail == fifo->num_entries) ? TRUE : FALSE;
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}
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bool sbi_fifo_is_full(struct sbi_fifo *fifo)
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{
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bool ret;
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spin_lock(&fifo->qlock);
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ret = __sbi_fifo_is_full(fifo);
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spin_unlock(&fifo->qlock);
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return ret;
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}
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/* Note: must be called with fifo->qlock held */
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static inline bool __sbi_fifo_is_empty(struct sbi_fifo *fifo)
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{
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return (fifo->avail == 0) ? TRUE : FALSE;
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}
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bool sbi_fifo_is_empty(struct sbi_fifo *fifo)
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{
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bool ret;
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spin_lock(&fifo->qlock);
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ret = __sbi_fifo_is_empty(fifo);
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spin_unlock(&fifo->qlock);
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return ret;
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}
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int sbi_fifo_enqueue(struct sbi_fifo *fifo, void *data)
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{
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if (!fifo || !data)
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return SBI_EINVAL;
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spin_lock(&fifo->qlock);
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if (__sbi_fifo_is_full(fifo)) {
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spin_unlock(&fifo->qlock);
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return SBI_ENOSPC;
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}
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memcpy(fifo->queue + fifo->head * fifo->entry_size, data,
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fifo->entry_size);
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fifo->avail++;
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fifo->head++;
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if (fifo->head >= fifo->num_entries)
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fifo->head = 0;
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spin_unlock(&fifo->qlock);
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return 0;
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}
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int sbi_fifo_dequeue(struct sbi_fifo *fifo, void *data)
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{
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if (!fifo || !data)
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return SBI_EINVAL;
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spin_lock(&fifo->qlock);
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if (__sbi_fifo_is_empty(fifo)) {
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spin_unlock(&fifo->qlock);
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return SBI_ENOENT;
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}
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memcpy(data, fifo->queue + fifo->tail * fifo->entry_size,
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fifo->entry_size);
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fifo->avail--;
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fifo->tail++;
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if (fifo->tail >= fifo->num_entries)
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fifo->tail = 0;
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spin_unlock(&fifo->qlock);
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return 0;
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}
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