/**
* Searched a statically assigned array for a free entry
* Starts with the last given element + 1 for optimisation
* This call is safe from both ISR and task context
* @return poiter to a free csp_packet_t or NULL if out of memory
*/
void * csp_buffer_get(size_t buf_size) {
void * buffer;
CSP_ENTER_CRITICAL(csp_critical_lock);
buffer = csp_buffer_get_isr(buf_size);
CSP_EXIT_CRITICAL(csp_critical_lock);
return buffer;
}
/** pbuf_cleanup
* Purge all packets buffers that have timed out
*/
static void pbuf_cleanup(void) {
int i;
pbuf_element_t *buf;
/* Lock packet buffer */
CSP_ENTER_CRITICAL(pbuf_sem);
/* Loop through buffer elements */
for (i = 0; i < PBUF_ELEMENTS; i++) {
buf = &pbuf[i];
if (buf->state == BUF_USED) {
/* Check timeout */
uint32_t now = csp_get_ms();
if (now - buf->last_used > PBUF_TIMEOUT_MS) {
csp_log_info("CAN Buffer element timed out\r\n");
/* Reuse packet buffer */
pbuf_free(buf, NULL);
}
}
}
/* Unlock packet buffer */
CSP_EXIT_CRITICAL(pbuf_sem);
}
/** pbuf_find
* Find matching packet buffer or create a new one.
* @param id CFP identifier to match
* @param mask Match mask
* @return Pointer to matching or new packet buffer element on success, NULL on error.
*/
static pbuf_element_t *pbuf_find(uint32_t id, uint32_t mask, CSP_BASE_TYPE *task_woken) {
/* Search for matching buffer */
int i;
pbuf_element_t *buf, *ret = NULL;
/* Lock packet buffer */
if (task_woken == NULL)
CSP_ENTER_CRITICAL(pbuf_sem);
/* Loop through buffer elements */
for (i = 0; i < PBUF_ELEMENTS; i++) {
buf = &pbuf[i];
if((buf->state == BUF_USED) && ((buf->cfpid & mask) == (id & mask))) {
pbuf_timestamp(buf, task_woken);
ret = buf;
break;
}
}
/* Unlock packet buffer */
if (task_woken == NULL)
CSP_EXIT_CRITICAL(pbuf_sem);
/* No matching buffer was found */
return ret;
}
/** pbuf_new
* Get new packet buffer element.
* @param id CFP identifier
* @return Pointer to packet buffer element on success, NULL on error.
*/
static pbuf_element_t *pbuf_new(uint32_t id, CSP_BASE_TYPE *task_woken) {
/* Search for free buffer */
int i;
pbuf_element_t *buf, *ret = NULL;
/* Lock packet buffer */
if (task_woken == NULL)
CSP_ENTER_CRITICAL(pbuf_sem);
/* Loop through buffer elements */
for (i = 0; i < PBUF_ELEMENTS; i++) {
buf = &pbuf[i];
if(buf->state == BUF_FREE) {
buf->state = BUF_USED;
buf->cfpid = id;
buf->remain = 0;
pbuf_timestamp(buf, task_woken);
ret = buf;
break;
}
}
/* Unlock packet buffer */
if (task_woken == NULL)
CSP_EXIT_CRITICAL(pbuf_sem);
/* No free buffer was found */
return ret;
}
/** pbuf_free
* Free buffer element and associated CSP packet buffer element.
* @param buf Buffer element to free
* @param free_packet true if the associated packet should be freed as well
* @return 0 on success, -1 on error.
*/
static int pbuf_free(pbuf_element_t *buf, CSP_BASE_TYPE *task_woken, bool free_packet) {
int ret;
/* Lock packet buffer */
if (task_woken == NULL)
CSP_ENTER_CRITICAL(pbuf_sem);
ret = pbuf_free_locked(buf, task_woken, free_packet);
/* Unlock packet buffer */
if (task_woken == NULL)
CSP_EXIT_CRITICAL(pbuf_sem);
return ret;
}
/** pbuf_free
* Free buffer element and associated CSP packet buffer element.
* @param buf Buffer element to free
* @return 0 on success, -1 on error.
*/
static int pbuf_free(pbuf_element_t *buf, CSP_BASE_TYPE *task_woken) {
int32_t refcount;
/* Lock packet buffer */
if (task_woken == NULL)
CSP_ENTER_CRITICAL(pbuf_sem);
/* Free CSP packet */
if (buf->packet != NULL) {
/* first check to see if the buffer was already free. This could happen
if the top level timeout occurred already. If so, no need to free it
again */
refcount = csp_buffer_get_refcount(buf->packet);
if (refcount > 0) {
if (task_woken == NULL) {
csp_buffer_free(buf->packet);
} else {
csp_buffer_free_isr(buf->packet);
}
}
buf->packet = NULL;
}
/* Mark buffer element free */
buf->state = BUF_FREE;
buf->rx_count = 0;
buf->tx_count = 0;
buf->cfpid = 0;
buf->last_used = 0;
buf->remain = 0;
/* Unlock packet buffer */
if (task_woken == NULL)
CSP_EXIT_CRITICAL(pbuf_sem);
return CSP_ERR_NONE;
}
