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/*
* 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 <sbi/sbi_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;
sbi_memset(fifo->queue, 0, (size_t)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;
}
u16 sbi_fifo_avail(struct sbi_fifo *fifo)
{
u16 ret;
if (!fifo)
return 0;
spin_lock(&fifo->qlock);
ret = fifo->avail;
spin_unlock(&fifo->qlock);
return ret;
}
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 void __sbi_fifo_enqueue(struct sbi_fifo *fifo, void *data)
{
u32 head;
head = (u32)fifo->tail + fifo->avail;
if (head >= fifo->num_entries)
head = head - fifo->num_entries;
sbi_memcpy(fifo->queue + head * fifo->entry_size, data, fifo->entry_size);
fifo->avail++;
}
/* 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;
}
/* Note: must be called with fifo->qlock held */
static inline void __sbi_fifo_reset(struct sbi_fifo *fifo)
{
size_t size = (size_t)fifo->num_entries * fifo->entry_size;
fifo->avail = 0;
fifo->tail = 0;
sbi_memset(fifo->queue, 0, size);
}
bool sbi_fifo_reset(struct sbi_fifo *fifo)
{
if (!fifo)
return FALSE;
spin_lock(&fifo->qlock);
__sbi_fifo_reset(fifo);
spin_unlock(&fifo->qlock);
return TRUE;
}
/**
* Provide a helper function to do inplace update to the fifo.
* Note: The callback function is called with lock being held.
*
* **Do not** invoke any other fifo function from callback. Otherwise, it will
* lead to deadlock.
*/
int sbi_fifo_inplace_update(struct sbi_fifo *fifo, void *in,
int (*fptr)(void *in, void *data))
{
int i, index = 0;
int ret = SBI_FIFO_UNCHANGED;
void *entry;
if (!fifo || !in)
return ret;
spin_lock(&fifo->qlock);
if (__sbi_fifo_is_empty(fifo)) {
spin_unlock(&fifo->qlock);
return ret;
}
for (i = 0; i < fifo->avail; i++) {
index = fifo->tail + i;
if (index >= fifo->num_entries)
index = index - fifo->num_entries;
entry = (void *)fifo->queue + (u32)index * fifo->entry_size;
ret = fptr(in, entry);
if (ret == SBI_FIFO_SKIP || ret == SBI_FIFO_UPDATED) {
break;
}
}
spin_unlock(&fifo->qlock);
return ret;
}
int sbi_fifo_enqueue(struct sbi_fifo *fifo, void *data)
{
if (!fifo || !data)
return SBI_EINVAL;
spin_lock(&fifo->qlock);
if (__sbi_fifo_is_full(fifo)) {
spin_unlock(&fifo->qlock);
return SBI_ENOSPC;
}
__sbi_fifo_enqueue(fifo, data);
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;
}
sbi_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;
}
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