static int dctcp_rcvr_flow_control(struct dtcp_ps * ps, const struct pci * pci)
{
struct dtcp * dtcp = ps->dm;
struct dctcp_dtcp_ps_data * data = ps->priv;
seq_num_t new_credit;
uint_t alpha_old = 0;
spin_lock_bh(&dtcp->parent->sv_lock);
new_credit = dtcp->sv->rcvr_credit;
if (data->state == SLOW_START) {
new_credit++;
if (new_credit >= data->sshtresh) {
data->state = CONG_AVOID;
}
} else {
data->dec_credit += DEC_PRECISION/new_credit;
if (data->dec_credit >= DEC_PRECISION) {
new_credit++;
data->dec_credit -= DEC_PRECISION;
}
}
spin_unlock_bh(&dtcp->parent->sv_lock);
data->sent_total++;
alpha_old = data->dctcp_alpha;
if ((pci_flags_get(pci) & PDU_FLAGS_EXPLICIT_CONGESTION)) {
data->ecn_total++;
/* alpha = (1-g) * alpha + g * F according DCTCP kernel patch */
data->dctcp_alpha = alpha_old - (alpha_old >> data->shift_g) + (data->ecn_total << (10 - data->shift_g)) / data->sent_total;
new_credit = max(new_credit - ((new_credit * data->dctcp_alpha) >> 11U), 2U);
data->sshtresh = new_credit;
data->state = CONG_AVOID;
LOG_DBG("DCTCP DTCP: dctcp_alpha: %d, new_credit %d", data->dctcp_alpha, new_credit);
}
static int mark_pdu(struct du * ret_pdu)
{
pdu_flags_t pci_flags;
pci_flags = pci_flags_get(&ret_pdu->pci);
pci_flags_set(&ret_pdu->pci, pci_flags |= PDU_FLAGS_EXPLICIT_CONGESTION);
LOG_DBG("ECN bit marked");
return 0;
}
static int serialize_base_pci(const struct serdes * instance,
char * data,
const struct pci * pci,
size_t pdu_len)
{
int offset;
address_t addr;
cep_id_t cep;
qos_id_t qos;
pdu_type_t type;
pdu_flags_t flags;
struct dt_cons * dt_cons;
ASSERT(instance);
ASSERT(data);
ASSERT(pci_is_ok(pci));
ASSERT(pdu_len);
dt_cons = instance->dt_cons;
ASSERT(dt_cons);
/*
* Putting 1 as version number for now
* If another version is needed, this will have to change
* Always 8 bit long
*/
offset = 0;
memcpy(data + offset, &version, VERSION_SIZE);
offset += VERSION_SIZE;
LOG_DBG("Serialized version %d, with size %d", version, VERSION_SIZE);
addr = pci_destination(pci);
memcpy(data + offset, &addr, dt_cons->address_length);
offset += dt_cons->address_length;
addr = pci_source(pci);
memcpy(data + offset, &addr, dt_cons->address_length);
offset += dt_cons->address_length;
qos = pci_qos_id(pci);
memcpy(data + offset, &qos, dt_cons->qos_id_length);
offset += dt_cons->qos_id_length;
cep = pci_cep_source(pci);
memcpy(data + offset, &cep, dt_cons->cep_id_length);
offset += dt_cons->cep_id_length;
cep = pci_cep_destination(pci);
memcpy(data + offset, &cep, dt_cons->cep_id_length);
offset += dt_cons->cep_id_length;
type = pci_type(pci);
memcpy(data + offset, &type, PDU_TYPE_SIZE);
offset += PDU_TYPE_SIZE;
flags = pci_flags_get(pci);
memcpy(data + offset, &flags, FLAGS_SIZE);
offset += FLAGS_SIZE;
memcpy(data + offset, &pdu_len, dt_cons->length_length);
offset += dt_cons->length_length;
return 0;
}