acrn-hypervisor/hypervisor/debug/sbuf.c

119 lines
2.6 KiB
C

/*
* SHARED BUFFER
*
* Copyright (C) 2017 Intel Corporation. All rights reserved.
*
* SPDX-License-Identifier: BSD-3-Clause
*
* Li Fei <fei1.li@intel.com>
*
*/
#include <hypervisor.h>
static inline bool sbuf_is_empty(const struct shared_buf *sbuf)
{
return (sbuf->head == sbuf->tail);
}
uint32_t sbuf_next_ptr(uint32_t pos_arg,
uint32_t span, uint32_t scope)
{
uint32_t pos = pos_arg;
pos += span;
pos = (pos >= scope) ? (pos - scope) : pos;
return pos;
}
uint32_t sbuf_get(struct shared_buf *sbuf, uint8_t *data)
{
const void *from;
uint32_t ele_size;
stac();
if (sbuf_is_empty(sbuf)) {
clac();
/* no data available */
return 0;
}
from = (void *)sbuf + SBUF_HEAD_SIZE + sbuf->head;
(void)memcpy_s((void *)data, sbuf->ele_size, from, sbuf->ele_size);
sbuf->head = sbuf_next_ptr(sbuf->head, sbuf->ele_size, sbuf->size);
ele_size = sbuf->ele_size;
clac();
return ele_size;
}
/**
* The high caller should guarantee each time there must have
* sbuf->ele_size data can be write form data and this function
* should guarantee execution atomically.
*
* flag:
* If OVERWRITE_EN set, buf can store (ele_num - 1) elements at most.
* Should use lock to guarantee that only one read or write at
* the same time.
* if OVERWRITE_EN not set, buf can store (ele_num - 1) elements
* at most. Shouldn't modify the sbuf->head.
*
* return:
* ele_size: write succeeded.
* 0: no write, buf is full
* negative: failed.
*/
uint32_t sbuf_put(struct shared_buf *sbuf, uint8_t *data)
{
void *to;
uint32_t next_tail;
uint32_t ele_size;
bool trigger_overwrite = false;
stac();
next_tail = sbuf_next_ptr(sbuf->tail, sbuf->ele_size, sbuf->size);
/* if this write would trigger overrun */
if (next_tail == sbuf->head) {
/* accumulate overrun count if necessary */
sbuf->overrun_cnt += sbuf->flags & OVERRUN_CNT_EN;
if ((sbuf->flags & OVERWRITE_EN) == 0U) {
/* if not enable over write, return here. */
clac();
return 0;
}
trigger_overwrite = true;
}
to = (void *)sbuf + SBUF_HEAD_SIZE + sbuf->tail;
(void)memcpy_s(to, sbuf->ele_size, data, sbuf->ele_size);
if (trigger_overwrite) {
sbuf->head = sbuf_next_ptr(sbuf->head,
sbuf->ele_size, sbuf->size);
}
sbuf->tail = next_tail;
ele_size = sbuf->ele_size;
clac();
return ele_size;
}
int32_t sbuf_share_setup(uint16_t pcpu_id, uint32_t sbuf_id, uint64_t *hva)
{
if ((pcpu_id >= get_pcpu_nums()) || (sbuf_id >= ACRN_SBUF_ID_MAX)) {
return -EINVAL;
}
per_cpu(sbuf, pcpu_id)[sbuf_id] = hva;
pr_info("%s share sbuf for pCPU[%u] with sbuf_id[%u] setup successfully",
__func__, pcpu_id, sbuf_id);
return 0;
}