// Handle randomly selected pending write
void handle_buffer_read(struct cmd *cmd)
{
struct cmd_event *event;
// Check that cmd struct is valid buffer read is available
if ((cmd == NULL) || (cmd->buffer_read != NULL))
return;
// Randomly select a pending write (or none)
event = cmd->list;
while (event != NULL) {
if ((event->type == CMD_WRITE) &&
(event->state == MEM_TOUCHED) &&
((event->client_state != CLIENT_VALID) ||
!allow_reorder(cmd->parms))) {
break;
}
event = event->_next;
}
// Test for client disconnect
if ((event == NULL) || (_get_client(cmd, event) == NULL))
return;
// Send buffer read request to AFU. Setting cmd->buffer_read
// will block any more buffer read requests until buffer read
// data is returned and handled in handle_buffer_data().
if (psl_buffer_read(cmd->afu_event, event->tag, event->addr,
CACHELINE_BYTES) == PSL_SUCCESS) {
cmd->buffer_read = event;
debug_cmd_buffer_read(cmd->dbg_fp, cmd->dbg_id, event->tag);
event->state = MEM_BUFFER;
}
}
static void buffer_event (int rnw, uint32_t tag, uint8_t *addr) {
uint8_t par[2];
if (status.psl_state==PSL_FLUSHING) {
#ifdef DEBUG
printf ("Response FLUSHED tag=0x%02x\n", tag);
#endif /* #ifdef DEBUG */
add_resp (tag, PSL_RESPONSE_FLUSHED);
return;
}
if (!testmemaddr (addr)) {
printf ("AFU attempted ");
if (rnw)
printf ("write");
else
printf ("read");
printf (" to invalid address 0x%016llx\n",(long long) addr);
#ifdef DEBUG
printf ("Response AERROR tag=0x%02x\n", tag);
#endif /* #ifdef DEBUG */
add_resp (tag, PSL_RESPONSE_AERROR);
status.psl_state = PSL_FLUSHING;
return;
}
if (rnw) {
#ifdef DEBUG
printf ("Buffer Read tag=0x%02x\n", tag);
#endif /* #ifdef DEBUG */
psl_buffer_read (status.event, tag, (uint64_t) addr,
CACHELINE_BYTES);
}
else {
#ifdef DEBUG
printf ("Buffer Write tag=0x%02x\n", tag);
#endif /* #ifdef DEBUG */
generate_cl_parity(addr, par);
psl_buffer_write (status.event, tag, (uint64_t) addr,
CACHELINE_BYTES,
addr, par);
++status.credits;
#ifdef DEBUG
printf ("Response tag=0x%02x\n", tag);
#endif /* #ifdef DEBUG */
if (status.psl_state==PSL_NLOCK) {
#ifdef DEBUG
printf ("Nlock response for read, tag=0x%02x\n", tag);
fflush (stdout);
#endif /* #ifdef DEBUG */
add_resp (tag, PSL_RESPONSE_NLOCK);
}
else if (!PAGED_RANDOMIZER || (rand() % PAGED_RANDOMIZER)) {
// Inject random "Paged" response
add_resp (tag, PSL_RESPONSE_DONE);
}
else {
add_resp (tag, PSL_RESPONSE_PAGED);
status.psl_state = PSL_FLUSHING;
}
}
}