Files
opensbi/lib/sbi_fifo.c
Anup Patel 3fbe233a15 lib: Pack struct sbi_fifo
This patch reduces memory consumed by struct sbi_fifo by droping
redundant "head" member and using u16 in-place of "unsigned long".

Signed-off-by: Anup Patel <anup.patel@wdc.com>
2019-04-03 13:48:38 -07:00

111 lines
2.1 KiB
C

/*
* SPDX-License-Identifier: BSD-2-Clause
*
* Copyright (c) 2019 Western Digital Corporation or its affiliates.
*
* Authors:
* Atish Patra<atish.patra@wdc.com>
*
*/
#include <sbi/riscv_locks.h>
#include <sbi/sbi_error.h>
#include <sbi/sbi_fifo.h>
#include <plat/string.h>
void sbi_fifo_init(struct sbi_fifo *fifo, void *queue_mem,
u16 entries, u16 entry_size)
{
fifo->queue = queue_mem;
fifo->num_entries = entries;
fifo->entry_size = entry_size;
SPIN_LOCK_INIT(&fifo->qlock);
fifo->avail = fifo->tail = 0;
memset(fifo->queue, 0, entries * entry_size);
}
/* Note: must be called with fifo->qlock held */
static inline bool __sbi_fifo_is_full(struct sbi_fifo *fifo)
{
return (fifo->avail == fifo->num_entries) ? TRUE : FALSE;
}
bool sbi_fifo_is_full(struct sbi_fifo *fifo)
{
bool ret;
spin_lock(&fifo->qlock);
ret = __sbi_fifo_is_full(fifo);
spin_unlock(&fifo->qlock);
return ret;
}
/* Note: must be called with fifo->qlock held */
static inline bool __sbi_fifo_is_empty(struct sbi_fifo *fifo)
{
return (fifo->avail == 0) ? TRUE : FALSE;
}
bool sbi_fifo_is_empty(struct sbi_fifo *fifo)
{
bool ret;
spin_lock(&fifo->qlock);
ret = __sbi_fifo_is_empty(fifo);
spin_unlock(&fifo->qlock);
return ret;
}
int sbi_fifo_enqueue(struct sbi_fifo *fifo, void *data)
{
u32 head;
if (!fifo || !data)
return SBI_EINVAL;
spin_lock(&fifo->qlock);
if (__sbi_fifo_is_full(fifo)) {
spin_unlock(&fifo->qlock);
return SBI_ENOSPC;
}
head = (u32)fifo->tail + fifo->avail;
if (head >= fifo->num_entries)
head = head - fifo->num_entries;
memcpy(fifo->queue + head * fifo->entry_size, data, fifo->entry_size);
fifo->avail++;
spin_unlock(&fifo->qlock);
return 0;
}
int sbi_fifo_dequeue(struct sbi_fifo *fifo, void *data)
{
if (!fifo || !data)
return SBI_EINVAL;
spin_lock(&fifo->qlock);
if (__sbi_fifo_is_empty(fifo)) {
spin_unlock(&fifo->qlock);
return SBI_ENOENT;
}
memcpy(data, fifo->queue + (u32)fifo->tail * fifo->entry_size,
fifo->entry_size);
fifo->avail--;
fifo->tail++;
if (fifo->tail >= fifo->num_entries)
fifo->tail = 0;
spin_unlock(&fifo->qlock);
return 0;
}